52 results on '"Kai M. Rösler"'
Search Results
2. Extent, impact, and predictors of diagnostic delay in Pompe disease: A combined survey approach to unveil the diagnostic odyssey
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Angelika Moder, Seyfullah Gökce, Thomas Hundsberger, Martina Huemer, Eugen Mengel, Julia B. Hennermann, Florian B. Lagler, Marianne Rohrbach, Nesrin Karabul, Kai M. Rösler, and University of Zurich
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Research Report ,Pediatrics ,medicine.medical_specialty ,Referral ,lcsh:QH426-470 ,Endocrinology, Diabetes and Metabolism ,610 Medicine & health ,Late onset ,Disease ,Biochemistry, Genetics and Molecular Biology (miscellaneous) ,lcsh:Diseases of the endocrine glands. Clinical endocrinology ,Internal Medicine ,medicine ,survey ,In patient ,expert centers ,lcsh:RC648-665 ,Descriptive statistics ,business.industry ,diagnostic odyssey ,Pompe disease ,Research Reports ,diagnostic delay ,patient perspective ,lcsh:Genetics ,10036 Medical Clinic ,business ,Time to diagnosis ,initial symptoms - Abstract
Background Early diagnosis is of substantial benefit for patients with Pompe disease. Yet underdiagnosing and substantial diagnostic delay are still frequent and the determinants of this are unknown. This study is the first to systematically investigate the diagnostic odyssey in Pompe disease from patients', parents', and physicians' perspectives. Methods Patients with infantile or late onset Pompe disease, their parents as well as their metabolic experts were invited to fill in respective surveys. The survey addressed perceived disease symptoms at onset and during the course of the disease, specialties of involved physicians, activities of patient-initiated search for diagnosis and the perceived impact of time to diagnosis on outcome. Results of experts' and patients'/parents' surveys were compared and expressed by descriptive statistics. Results and Discussion We collected data on 15 males and 17 females including 9 infantile and 23 late onset Pompe patients. All received the correct diagnosis at a metabolic or musculoskeletal expert center. Patients with direct referral to the expert center had the lowest diagnostic delay, while patients who were seen by several physicians, received the correct diagnosis after 44%-200% longer delay. The proportion of direct referral varied strongly between pediatricians (57%) and other disciplines (18%-36%). Conclusion Our study highlights a substantially larger diagnostic delay in Pompe patients that are not directly referred to expert centers for diagnostic work. Our findings may be used to develop more successful strategies for early diagnosis. Synopsis Diagnostic delay in Pompe disease is substantial particularly in patients that are not directly referred to expert centers for diagnostic workup, so facilitating direct referral may be a new strategy for early diagnosis.
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- 2019
3. Comparison of recent pivotal recommendations for the diagnosis and treatment of late-onset Pompe disease using diagnostic nodes-the Pompe disease burden scale
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Thomas Hundsberger, Benedikt Schoser, Paul Martin Putora, Daniela Leupold, and Kai M. Rösler
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Weakness ,medicine.medical_specialty ,Concordance ,610 Medicine & health ,Disease ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,Randomized controlled trial ,Cost of Illness ,law ,medicine ,Humans ,Respiratory function ,Enzyme Replacement Therapy ,030212 general & internal medicine ,Age of Onset ,Intensive care medicine ,Disease burden ,business.industry ,Glycogen Storage Disease Type II ,Decision Trees ,Enzyme replacement therapy ,Clinical research ,Treatment Outcome ,Neurology ,Practice Guidelines as Topic ,Neurology (clinical) ,medicine.symptom ,business ,030217 neurology & neurosurgery - Abstract
Pompe disease is a rare autosomal-recessive disorder characterised by limb-girdle myopathy and respiratory weakness in the late-onset form (LOPD). Various mutations in the acid alpha-glucosidase gene lead to toxic lysosomal and extra-lysosomal glycogen accumulation in all organs due to ineffective glycogen clearance by the encoded enzyme. Only one randomized trial demonstrated beneficial effects of respiratory function and meters walked in the 6-min walking test with enzyme replacement therapy (ERT). These results were confirmed in several retrospective and prospective observations and in meta-analyses. Due to a potential lifelong therapy, moderate efficacy and high treatment costs time of ERT initiation and cessation is an ongoing matter of debate. So far, several national and international recommendations have been published with different criteria concerning diagnosis, initiation and cessation of ERT in LOPD. We therefore formally analysed recent published recommendations and consensus statements of LOPD using diagnostic nodes (DODES) as a special software tool. With DODES, an objective analysis becomes possible if the content of the recommendations is represented as algorithms using cross-compatible elements. This analysis formally disclosed both, areas of great heterogeneity and concordance for the diagnosis and management of LOPD and paved the way for a Pompe disease burden scale focussing on ERT initiation. According to this investigation further clinical research should concentrate on ERT in pre-symptomatic and severely affected LOPD patients and on cessation criteria for ERT as these issues are areas of international uncertainty and discordance.
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- 2019
4. Nutrient pattern analysis in critically ill patients using Omics technology (NAChO) - Study protocol for a prospective observational study
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Werner J. Z’Graggen, Wolfram Doehner, Stefanie Wenger, Jukka Takala, Lionel Müller, Olivier Scheidegger, Anna S. Messmer, Stephan von Haehling, Tobias Konz, Bernard Cuenoud, Kai M. Rösler, Joerg C. Schefold, Stephan M. Jakob, Serge Rezzi, Dominik Grathwohl, Jamie S. McPhee, Michaela Fux, and Radu Olariu
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Adult ,Male ,medicine.medical_specialty ,Critical Illness ,ICU acquired weakness ,610 Medicine & health ,Mass Spectrometry ,law.invention ,Sepsis ,sepsis ,03 medical and health sciences ,0302 clinical medicine ,Enteral Nutrition ,proteomics ,law ,Study Protocol Clinical Trial ,Intensive care ,medicine ,Humans ,metabolic pathways ,030212 general & internal medicine ,Prospective Studies ,Prospective cohort study ,Intracerebral hemorrhage ,business.industry ,Septic shock ,Muscles ,General Medicine ,Nutrients ,medicine.disease ,brain injury ,Intensive care unit ,metabolomics ,Intensive Care Units ,Parenteral nutrition ,nutrition ,030220 oncology & carcinogenesis ,Brain Injuries ,Emergency medicine ,ComputingMethodologies_DOCUMENTANDTEXTPROCESSING ,Body Composition ,Quality of Life ,Observational study ,Female ,business ,Research Article - Abstract
Supplemental Digital Content is available in the text, Introduction: Intensive care unit-acquired weakness (ICU-AW) is often observed in critically ill patients with prolonged intensive care unit (ICU) stay. We hypothesized that evolving metabolic abnormalities during prolonged ICU stay are reflected by changing nutrient patterns in blood, urine and skeletal muscle, and that these patterns differ in patients with/without ICU-AW and between patients with/without sepsis. Methods: In a prospective single-center observational trial, we aim to recruit 100 critically ill patients (ICU length of stay ≥ 5 days) with severe sepsis/septic shock (“sepsis group”, n = 50) or severe head trauma/intracerebral hemorrhage (“CNS group”, n = 50). Patients will be sub-grouped for presence or absence of ICU-AW as determined by the Medical Research Council sum score. Blood and urine samples will be collected and subjected to comprehensive nutrient analysis at different time points by targeted quantitative mass spectrometric methods. In addition, changes in muscular tissue (biopsy, when available), muscular architecture (ultrasound), electrophysiology, body composition analyses (bioimpedance, cerebral magnetic resonance imaging), along with clinical status will be assessed. Patients will be followed-up for 180 and 360 days including assessment of quality of life. Discussion: Key objective of this trial is to assess changes in nutrient pattern in blood and urine over time in critically ill patients with/without ICU-AW by using quantitative nutrient analysis techniques. Peer-reviewed published NAChO data will allow for a better understanding of metabolic changes in critically ill patients on standard liquid enteral nutrition and will likely open up new avenues for future therapeutic and nutritional interventions.
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- 2019
5. Sural nerve conduction studies using ultrasound-guided needle positioning: Influence of age and recording location
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Olivier Scheidegger, Christian P. Kamm, Christina Kihm, and Kai M. Rösler
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030506 rehabilitation ,Physiology ,business.industry ,Snap ,Healthy subjects ,Sural nerve ,Anatomy ,Lateral malleolus ,Ultrasound guided ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,medicine.anatomical_structure ,Surface electrode ,Physiology (medical) ,Medicine ,Neurology (clinical) ,0305 other medical science ,business ,Orthodromic ,030217 neurology & neurosurgery ,Sensory nerve - Abstract
INTRODUCTION The aim of this study was to compare orthodromic sural nerve conduction study (NCS) results using ultrasound-guided needle positioning (USNP) to surface electrode recordings. METHODS 51 healthy subjects aged 24 - 80 years, divided into 5 age groups, were examined. Electrical stimuli were applied behind the lateral malleolus. Sensory nerve action potentials (SNAPs) were recorded 8 and 15 cm proximally with surface and needle electrodes. RESULTS Mean SNAP amplitudes in µV (surface/needle electrodes) averaged 12.7 (SD 7.6)/40.6 (SD 20.8), P 60 years. SNAP amplitudes were smaller at the proximal recording location. DISCUSSION NCS using USNP yield higher amplitude responses than surface electrodes in all age groups at all recording sites. SNAP amplitudes are smaller at proximal recording locations due to sural nerve branching. This article is protected by copyright. All rights reserved.
- Published
- 2016
6. 36-Months follow-up assessment after cessation and resuming of enzyme replacement therapy in late onset Pompe disease: data from the Swiss Pompe Registry
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Oliver Findling, Rafael Sauter, Kai M. Rösler, Thomas Hundsberger, Daniela Leupold, and Olivier Scheidegger
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0301 basic medicine ,Male ,congenital, hereditary, and neonatal diseases and abnormalities ,Vital capacity ,medicine.medical_specialty ,Pediatrics ,Neurology ,Late onset ,610 Medicine & health ,Disease ,Pulmonary function testing ,03 medical and health sciences ,0302 clinical medicine ,Quality of life ,medicine ,Humans ,Enzyme Replacement Therapy ,Prospective Studies ,Registries ,Retrospective Studies ,business.industry ,Glycogen Storage Disease Type II ,nutritional and metabolic diseases ,Enzyme replacement therapy ,030104 developmental biology ,Treatment Outcome ,Walk test ,Female ,Neurology (clinical) ,business ,030217 neurology & neurosurgery ,Switzerland ,Follow-Up Studies - Abstract
Although not curative, enzyme replacement therapy (ERT) with recombinant human acid alpha-glucosidase enzyme has shown to be effective in the treatment of late-onset Pompe disease (LOPD). For this potentially life-long treatment, little is known on the clinical effect of cessation and resuming ERT. Due to a Swiss supreme court decision on ERT reimbursement, a temporary stop of ERT occurred in our study population. The aim of this study was to report the 36-months follow-up assessments after resuming ERT. After resuming ERT, seven patients suffering from genetically and enzymatically confirmed LOPD had periodic, mandatory, prospective assessments of pulmonary function tests, muscle strength summary scores, distances walked in timed walking tests, and patient-reported questionnaires. Data were statistically analyzed for significant differences between time points at ERT cessation, at ERT resuming, and 36 months thereafter. After resuming ERT forced vital capacity (p = 0.007) and distance walked in the 6 min walk test (6-MWT, p = 0.011) significantly increased at 36 months. Compared to before ERT cessation, distance walked in 6-MWT at 36 months still remained significantly lower (p = 0.005). Self-reported scores in the fatigue severity scale significantly declined at 36 months after resuming ERT (p = 0.019). No other functional or reported parameter significantly changed at 36 months after resuming ERT. Our data suggests that long-term interruption of ERT in LOPD may lead to deterioration of clinical meaningful parameters and quality of life. In addition, a clinical restoration after ERT cessation is possible for most of the LOPD patients within a 36 months follow-up.
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- 2018
7. Cessation and resuming of alglucosidase alfa in Pompe disease: a retrospective analysis
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Thomas Hundsberger, Oliver Findling, and Kai M. Rösler
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Adult ,Male ,medicine.medical_specialty ,Vital capacity ,Pediatrics ,Time Factors ,Neurology ,Vital Capacity ,610 Medicine & health ,Walking ,FEV1/FVC ratio ,medicine ,Humans ,Enzyme Replacement Therapy ,Respiratory function ,Muscle Strength ,Alglucosidase alfa ,Retrospective Studies ,Glycogen Storage Disease Type II ,business.industry ,Respiration ,alpha-Glucosidases ,Retrospective cohort study ,Enzyme replacement therapy ,Middle Aged ,Surgery ,Treatment Outcome ,Breathing ,Female ,Neurology (clinical) ,business ,Switzerland ,medicine.drug - Abstract
Enzyme replacement therapy (ERT) with recombinant human alglucosidase alfa (rhGAA) in late-onset Pompe disease is moderately effective. Little is known about the clinical course after treatment termination and the resumption of ERT. In Switzerland, rhGAA therapy for Pompe disease was temporarily withdrawn after the federal court judged that the treatment costs were greatly out of proportion compared to the benefits. Re-treatment was initiated after the therapy was finally licensed. We retrospectively analysed seven Pompe patients, who underwent cessation and resumption of ERT (median age 43 years). The delay from first symptoms to final diagnosis ranged from 4 to 20 years. The demographics, clinical characteristics, assessments with the 6-min walking test (6-MWT), the predicted forced vital capacity (FVC) and muscle strength were analysed. Before initiation of ERT, all patients suffered from proximal muscle weakness of the lower limbs; one was wheelchair-bound and two patients received night-time non-invasive ventilation. Initial treatment stabilised respiratory function in most patients and improved their walking performance. After treatment cessation, upright FVC declined in most and the 6-MWT declined in all patients. Two patients needed additional non-invasive ventilatory support. Twelve months after resuming ERT, the respiratory and walking capacity improved again in most patients. However, aside for one patient, none of the patients reached the same level of respiratory function or distance walked in 6 min, as at the time of ERT withdrawal. We conclude that cessation of ERT in Pompe disease causes a decline in clinical function and should be avoided. Resuming treatment only partially recovers respiratory function and walking capacity.
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- 2014
8. Feasibility of Using EMG for Early Detection of the Facial Nerve During Robotic Direct Cochlear Access
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Stefan Weber, Kai M. Rösler, Kate Gavaghan, Tom Williamson, Juan Anso, Christina Stahl, M. Caversaccio, Brett Bell, and Nicolas Gerber
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medicine.medical_specialty ,medicine.medical_treatment ,610 Medicine & health ,Mastoidectomy ,Electromyography ,otorhinolaryngologic diseases ,medicine ,Animals ,Drill bit ,Ear canal ,Sheep ,630 Agriculture ,medicine.diagnostic_test ,Drill ,business.industry ,Robotics ,Cochlear Implantation ,Facial nerve ,Sensory Systems ,Cochlea ,Surgery ,Facial Nerve ,medicine.anatomical_structure ,Surgery, Computer-Assisted ,Otorhinolaryngology ,Models, Animal ,Neurology (clinical) ,Artificial intelligence ,business ,Fiducial marker ,Biomedical engineering - Abstract
HYPOTHESIS Facial nerve monitoring can be used synchronous with a high-precision robotic tool as a functional warning to prevent of a collision of the drill bit with the facial nerve during direct cochlear access (DCA). BACKGROUND Minimally invasive direct cochlear access (DCA) aims to eliminate the need for a mastoidectomy by drilling a small tunnel through the facial recess to the cochlea with the aid of stereotactic tool guidance. Because the procedure is performed in a blind manner, structures such as the facial nerve are at risk. Neuromonitoring is a commonly used tool to help surgeons identify the facial nerve (FN) during routine surgical procedures in the mastoid. Recently, neuromonitoring technology was integrated into a commercially available drill system enabling real-time monitoring of the FN. The objective of this study was to determine if this drilling system could be used to warn of an impending collision with the FN during robot-assisted DCA. MATERIALS AND METHODS The sheep was chosen as a suitable model for this study because of its similarity to the human ear anatomy. The same surgical workflow applicable to human patients was performed in the animal model. Bone screws, serving as reference fiducials, were placed in the skull near the ear canal. The sheep head was imaged using a computed tomographic scanner and segmentation of FN, mastoid, and other relevant structures as well as planning of drilling trajectories was carried out using a dedicated software tool. During the actual procedure, a surgical drill system was connected to a nerve monitor and guided by a custom built robot system. As the planned trajectories were drilled, stimulation and EMG response signals were recorded. A postoperative analysis was achieved after each surgery to determine the actual drilled positions. RESULTS Using the calibrated pose synchronized with the EMG signals, the precise relationship between distance to FN and EMG with 3 different stimulation intensities could be determined for 11 different tunnels drilled in 3 different subjects. CONCLUSION From the results, it was determined that the current implementation of the neuromonitoring system lacks sensitivity and repeatability necessary to be used as a warning device in robotic DCA. We hypothesize that this is primarily because of the stimulation pattern achieved using a noninsulated drill as a stimulating probe. Further work is necessary to determine whether specific changes to the design can improve the sensitivity and specificity.
- Published
- 2014
9. P13. Semi-automatic, machine-learning based segmentation of peripheral nerves for quantitative morphometry: Comparison of low- and high-resolution MR neurography
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Waldo Valenzuela, Fabian Balsiger, Benedikt Wagner, C. Steindel, Mauricio Reyes, Olivier Scheidegger, M. Arn, Marwan El-Koussy, and Kai M. Rösler
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Ground truth ,Computer science ,business.industry ,Magnetic resonance neurography ,Context (language use) ,Pattern recognition ,medicine.disease ,Sensory Systems ,Random forest ,Peripheral neuropathy ,Neurology ,Discriminative model ,Sørensen–Dice coefficient ,Physiology (medical) ,medicine ,Segmentation ,Neurology (clinical) ,Artificial intelligence ,business - Abstract
Background Current state-of-the-art to diagnose peripheral neuropathy are neurological examination and electrodiagnostic studies. However, deeply situated nerves and plexus remain difficult to assess using these techniques, hence magnetic resonance neurography (MRN) emerged as a complementary method. MRN remains a qualitative approach and quantification, in terms of extraction of imaging biomarkers is needed to facilitate diagnosis and for follow-up examinations. Towards a multi-parametric quantitative imaging approach, accurate nerve segmentation needs to be performed first. Hampered by time-consuming manual annotation, we developed a semi-automatic, time-effective, hence clinically feasible segmentation approach based on machine-learning algorithms. In this study, we compared its performance on low- and high-resolution MRN. Materials and methods We acquired images of 9 healthy volunteers at the upper leg using 3 MRN sequences: lower resolution turbo inversion recovery magnitude (TIRM, voxel size of 78 × 78 × 4.0 mm3), lower resolution spin echo T2-weighted (T2, voxel size .52 × .52 × 4.0 mm3), and high resolution, fat-suppressed spin echo T2-weighted (hrT2, voxel size .25 × .25 × 3.3 mm3). An expert manually segmented the sciatic nerve on the T2 and hrT2 images (ground truth, GT). Our segmentation algorithm is based on a decision forest with context- and intensity-based descriptors. We split the images into two sets: a multi-modal low-resolution (TIRM and T2), and a mono-modal high-resolution (hrT2). We perform a leave-one-out cross-validation for both sets and calculate the Dice coefficient to the manually annotated GT. Cross-sectional areas (CSA) were calculated from the middle slice of the image stack. Results Dice coefficients of 0.723 ± 0.202 and 0.735 ± 0.080 are achieved for the low- and high-resolution MRN images (p = 0.858, CI 95 %). Segmentation results and 3-D renderings of the same nerve segmented in low- and high-resolution are shown in Fig. 1 . CSA for GT were 34.0 ± 5.5 mm2 (T2), and 35.4 ± 8.5 mm2 (hrT2), using semi-automatic segmentation 24.8 ± 7.6 mm2 (T2), and 25.7 ± 10.6 mm2 (hrT2). Discussion and conclusion Semi-automatic, hence fast peripheral nerve segmentation is feasible in both low- and high-resolution MRN images of the upper leg, providing image-based quantitative morphometric data. The equal performance of the low-resolution images might be due to the multi-modal setting, which possibly provides more discriminative descriptors for nerve. The lower CSA using semi-automatic segmentation is due to more rigorous segmentation constraints. Future work will include the application of our method to localize and quantify nerve lesions in images of patients diagnosed with peripheral neuropathy.
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- 2018
10. A Neuromonitoring Approach to Facial Nerve Preservation During Image-guided Robotic Cochlear Implantation
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Nicolas Gerber, Christina Precht, Marco Caversaccio, Thomas Wyss Balmer, Helene Rohrbach, Stefan Weber, Kate Gavaghan, Damien Ferrario, Kai M. Rösler, Matthias S. Dettmer, Cilgia Dür, Tom Williamson, Enric M. Calvo, Juan Anso, and Brett Bell
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medicine.medical_treatment ,0206 medical engineering ,Mastoidectomy ,610 Medicine & health ,02 engineering and technology ,Electromyography ,Stimulus (physiology) ,Mastoid ,03 medical and health sciences ,Postoperative Complications ,0302 clinical medicine ,Animals ,Medicine ,030223 otorhinolaryngology ,Cochlear implantation ,Cranial Nerve Injuries ,Sheep ,medicine.diagnostic_test ,630 Agriculture ,business.industry ,Robotics ,Anatomy ,Surgical Instruments ,Cochlear Implantation ,Neurophysiological Monitoring ,020601 biomedical engineering ,Facial nerve ,Electric Stimulation ,Sensory Systems ,Shunting ,Facial Nerve ,medicine.anatomical_structure ,Surgery, Computer-Assisted ,Otorhinolaryngology ,Cranial Nerve Injury ,Middle ear ,570 Life sciences ,biology ,Neurology (clinical) ,Otologic Surgical Procedures ,business ,Biomedical engineering - Abstract
HYPOTHESIS A multielectrode probe in combination with an optimized stimulation protocol could provide sufficient sensitivity and specificity to act as an effective safety mechanism for preservation of the facial nerve in case of an unsafe drill distance during image-guided cochlear implantation. BACKGROUND A minimally invasive cochlear implantation is enabled by image-guided and robotic-assisted drilling of an access tunnel to the middle ear cavity. The approach requires the drill to pass at distances below 1 mm from the facial nerve and thus safety mechanisms for protecting this critical structure are required. Neuromonitoring is currently used to determine facial nerve proximity in mastoidectomy but lacks sensitivity and specificity necessaries to effectively distinguish the close distance ranges experienced in the minimally invasive approach, possibly because of current shunting of uninsulated stimulating drilling tools in the drill tunnel and because of nonoptimized stimulation parameters. To this end, we propose an advanced neuromonitoring approach using varying levels of stimulation parameters together with an integrated bipolar and monopolar stimulating probe. MATERIALS AND METHODS An in vivo study (sheep model) was conducted in which measurements at specifically planned and navigated lateral distances from the facial nerve were performed to determine if specific sets of stimulation parameters in combination with the proposed neuromonitoring system could reliably detect an imminent collision with the facial nerve. For the accurate positioning of the neuromonitoring probe, a dedicated robotic system for image-guided cochlear implantation was used and drilling accuracy was corrected on postoperative microcomputed tomographic images. RESULTS From 29 trajectories analyzed in five different subjects, a correlation between stimulus threshold and drill-to-facial nerve distance was found in trajectories colliding with the facial nerve (distance 95%) at distances to the facial nerve below 0.5 mm. However, reduction in stimulus threshold to 0.3 mA or lower resulted in a decrease of facial nerve distance detection range below 0.1 mm (>95% sensitivity). Subsequent histopathology follow-up of three representative cases where the neuromonitoring system could reliably detect a collision with the facial nerve (distance
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- 2016
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11. Reproducibility of sensory nerve conduction studies of the sural nerve using ultrasound-guided needle positioning
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Kai M. Rösler, Alexander F. Kuffer, Christian P. Kamm, and Olivier Scheidegger
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Needle electrode ,Reproducibility ,Physiology ,business.industry ,Magnetic resonance neurography ,Ultrasound ,Sural nerve ,Anatomy ,behavioral disciplines and activities ,Ultrasound guided ,Cellular and Molecular Neuroscience ,medicine.anatomical_structure ,Physiology (medical) ,mental disorders ,medicine ,Neurology (clinical) ,Nerve conduction ,business ,Sensory nerve ,Biomedical engineering - Abstract
In this study we sought to evaluate the reproducibility of sensory nerve conduction studies (NCS) using ultrasound-guided needle positioning (USNP).
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- 2011
12. Ultrasound-guided needle positioning in sensory nerve conduction study of the sural nerve
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Kai M. Rösler, Christian P. Kamm, and Olivier Scheidegger
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Adult ,Male ,Adolescent ,Sensory Receptor Cells ,Neural Conduction ,Action Potentials ,Neurophysiology ,Pilot Projects ,Sural nerve ,Sensory system ,Young Adult ,Sural Nerve ,Physiology (medical) ,mental disorders ,medicine ,Humans ,Electrodes ,Aged ,Ultrasonography ,Aged, 80 and over ,business.industry ,Ultrasound ,Snap ,Middle Aged ,medicine.disease ,Sensory Systems ,medicine.anatomical_structure ,Neurology ,Anesthesia ,Female ,Neurology (clinical) ,business ,Orthodromic ,Polyneuropathy ,Biomedical engineering ,Sensory nerve - Abstract
To evaluate the usefulness of ultrasound imaging to improve the positioning of the recording needle for nerve conduction studies (NCS) of the sural nerve.Orthodromic NCS of the sural nerve was performed in 44 consecutive patients evaluated for polyneuropathy. Ultrasound-guided needle positioning (USNP) was compared to conventional "blind" needle positioning (BNP), electrically guided needle positioning (EGNP), and to recordings with surface electrodes (SFN).The mean distance between the needle tip and the nerve was 1.1 mm with USNP compared to 5.1 mm with BNP (p0.0001). The mean amplitude of the sensory nerve action potential (SNAP) was 21 microV with USNP and 11 microV with BNP (p0.0001). Compared to BNP, nerve-needle distances and SNAP amplitudes did not improve with EGNP. SNAP amplitudes recorded with SFN were significantly smaller than with BNP, EGNP and USNP.Ultrasound increases the precision of needle positioning markedly, compared to conventional methods. The amplitude of the recorded SNAP is usually clearly greater using USNP. In addition, USNP is faster, less painful and less dependent on the patient.USNP is superior to BNP, EGNP, and SFN in accurate measurement of SNAP amplitude. It has a potential use in the routine near-nerve needle sensory NCS of pure sensory nerves.
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- 2009
13. Repetitive spinal motor neuron discharges following single transcranial magnetic stimuli: a quantitative study
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Michel R. Magistris, Werner J. Z’Graggen, N. Durisch, A.M. Humm, and Kai M. Rösler
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Adult ,Male ,medicine.medical_treatment ,Neural Conduction ,Action Potentials ,Stimulation ,Stimulus (physiology) ,Efferent Pathways ,Magnetics ,Anterior Horn Cells ,Physiology (medical) ,Reaction Time ,medicine ,Humans ,Peripheral Nerves ,Axon ,Muscle, Skeletal ,business.industry ,Electrodiagnosis ,Motor Cortex ,Motor neuron ,Evoked Potentials, Motor ,Hand ,Electric Stimulation ,Sensory Systems ,Electrophysiology ,Transcranial magnetic stimulation ,medicine.anatomical_structure ,Neurology ,Female ,Neurology (clinical) ,medicine.symptom ,business ,Neuroscience ,Muscle contraction ,Motor cortex - Abstract
Objective To quantify repetitive discharges of spinal motor neurons (repMNDs) in response to single transcranial magnetic stimuli (TMS). To assess their contribution to the size of motor evoked potentials (MEPs). Methods We combined the triple stimulation technique (TST) with an additional nerve stimulus in the periphery (=quadruple stimulation; QuadS). The QuadS eliminates the first action potential descending on each axon after TMS, and eliminates effects on response size induced by desynchronization of these discharges, thereby allowing a quantification of motor neurons (MNs) discharging twice. In some instances, a quintuple stimulation (QuintS) was used, to quantify the number of MNs discharging three times. Recordings were from the abductor digiti minimi of 14 healthy subjects, using two different stimulation intensities and three different levels of facilitatory muscle precontractions. Results The threshold to obtain repMNDs was high. Their maximal size differed markedly between subjects, ranging from 8 to 52% of all MNs. Stimulation intensity and facilitatory muscle contraction, but not resting motor threshold, correlated with the amount of repMNDs. QuintS never yielded discernible responses, hence all observed repMNDs were double discharges. RepMNDs contributed to the MEP areas, but did not influence MEP amplitudes. Conclusions QuadS and QuintS allow precise quantification of repMNDs. The threshold of repMNDs is high and varies considerably between subjects. Significance repMNDs have to be considered when MEP areas are measured. Their analysis may be of interest in neurological disorders, but standardized stimulation parameters appear essential.
- Published
- 2005
14. Assessment of central motor conduction to intrinsic hand muscles using the triple stimulation technique: normal values and repeatability
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Kai M. Rösler, N.E. von Hornstein, Werner J. Z’Graggen, A.M. Humm, and Michel R. Magistris
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Adult ,Male ,medicine.medical_treatment ,Neural Conduction ,Pilot Projects ,Fingers ,Magnetics ,Physical Stimulation ,Physiology (medical) ,medicine ,Humans ,Muscle, Skeletal ,Abductor pollicis brevis muscle ,business.industry ,Motor Cortex ,Reproducibility of Results ,Motor control ,Repeatability ,Anatomy ,Middle Aged ,Motor neuron ,bacterial infections and mycoses ,Sensory Systems ,Peripheral ,Transcranial magnetic stimulation ,Electrophysiology ,medicine.anatomical_structure ,Neurology ,Female ,sense organs ,Neurology (clinical) ,business ,Motor cortex ,Biomedical engineering - Abstract
Objective : To establish the triple stimulation technique (TST) for recordings from the first dorsal interosseus (FDI) and the abductor pollicis brevis muscles (APB), and to analyse the test–retest repeatability of the TST measurements in APB. Methods : The recently developed TST was slightly modified for recordings from small hand muscles to account for volume conducted activity from surrounding muscles. The TST combines transcranial magnetic stimulation (TMS) with a peripheral collision technique [Magistris et al. Brain 121 (1998) 437]. In contrast to conventional motor-evoked potentials (MEPs), it quantifies the number of conducting central motor neurons (expressed by the TST amplitude ratio, TST–AR). MEPs and TST were performed in 30 sides of 25 healthy subjects (target muscle FDI), and in 29 sides of 21 healthy subjects (target muscle APB). All APB recordings were repeated after 25±5.9 days. Results : The TST–AR averaged 97.4±2.5% in FDI and 95.9±4.7% in APB. There was a mean difference of the TST–AR ratio of 2.9±3.1% between the repeated APB recordings (95% limits of agreement±6.3%). Conclusions : TMS allows activation of virtually all motor neurons supplying FDI and APB, when effects of volume conduction are eliminated. Its test–retest repeatability is excellent. Significance : The TST is well suited for follow-up examinations of central motor conduction failures. The greater number of established target muscles widens its clinical applicability.
- Published
- 2004
15. Quantification of Uhthoff's phenomenon in multiple sclerosis: a magnetic stimulation study
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A.M. Humm, Michel R. Magistris, Jürg Kesselring, Kai M. Rösler, J. Kool, Serafin Beer, and Molecular and Computational Toxicology
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Adult ,Male ,medicine.medical_specialty ,Multiple Sclerosis ,Neural Conduction ,Stimulation ,Uhthoff's phenomenon ,Body Temperature ,Central nervous system disease ,Magnetics ,Physiology (medical) ,Internal medicine ,Motor system ,medicine ,Reaction Time ,Humans ,Aged ,Pyramidal tracts ,business.industry ,Multiple sclerosis ,Brain ,Motor neuron ,Middle Aged ,bacterial infections and mycoses ,medicine.disease ,Evoked Potentials, Motor ,Sensory Systems ,Electric Stimulation ,Electrophysiology ,medicine.anatomical_structure ,Neurology ,Cardiology ,Female ,Neurology (clinical) ,business ,Neuroscience ,Motor cortex - Abstract
Objective : To quantify temperature induced changes (=Uhthoff phenomenon) in central motor conduction and their relation to clinical motor deficits in 20 multiple sclerosis (MS) patients. Methods : Self-assessment of vulnerability to temperature and clinical examination were performed. We used motor evoked potentials to measure central motor conduction time (CMCT) and applied the triple stimulation technique (TST) to assess conduction failure. The TST allows an accurate quantification of the proportion of conducting central motor neurons, expressed by the TST amplitude ratio (TST-AR). Results : Temperature induced changes of TST-AR were significantly more marked in patients with prolonged CMCT ( P =0.037). There was a significant linear correlation between changes of TST-AR and walking velocity ( P =0.0002). Relationships were found between pronounced subjective vulnerability to temperature and (i) abnormal CMCT ( P =0.02), (ii) temperature induced changes in TST-AR ( P =0.04) and (iii) temperature induced changes in walking velocity ( P =0.04). CMCT remained virtually unchanged by temperature modification. Conclusions : Uhthoff phenomena in the motor system are due to varying degrees of conduction block and associated with prolonged CMCT. In contrast to conduction block, CMCT is not importantly affected by temperature. Significance : This is the first study quantifying the Uhthoff phenomenon in the pyramidal tract of MS patients. The results suggest that patients with central conduction slowing are particularly vulnerable to develop temperature-dependent central motor conduction blocks.
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- 2004
16. Central motor conduction differs between acute relapsing–remitting and chronic progressive multiple sclerosis
- Author
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A.M. Humm, Christian W. Hess, André Truffert, Michel R. Magistris, and Kai M. Rösler
- Subjects
Adult ,Male ,medicine.medical_specialty ,Pathology ,Adolescent ,medicine.medical_treatment ,Neural Conduction ,Nerve conduction velocity ,Central nervous system disease ,Magnetics ,Multiple Sclerosis, Relapsing-Remitting ,Physiology (medical) ,Internal medicine ,Immunopathology ,Reaction Time ,Humans ,Medicine ,Aged ,Motor Neurons ,business.industry ,Multiple sclerosis ,Middle Aged ,Multiple Sclerosis, Chronic Progressive ,Evoked Potentials, Motor ,medicine.disease ,Spinal cord ,Electric Stimulation ,Sensory Systems ,Transcranial magnetic stimulation ,medicine.anatomical_structure ,Neurology ,Acute Disease ,Cardiology ,Female ,Neurology (clinical) ,business ,Motor Deficit ,Motor cortex - Abstract
To characterize central motor conduction in relation to the clinical deficits and to the disease duration in 90 patients with acute relapsing-remitting MS (RR-MS) and in 51 patients with chronic primary or secondary progressive MS (P-MS).The triple stimulation technique (TST) was used to quantify the central motor conduction failure (expressed by the TST amplitude ratio) and conventional motor evoked potentials (MEPs) were used to measure the central motor conduction time (CMCT).The TST amplitude ratio was reduced in presence of a clinical motor deficit (p=0.02 for RR-MS, p0.01 for P-MS), but did not significantly differ in RR-MS and P-MS (p0.05) when patients with similar clinical motor deficit were compared. The CMCT was not related to the clinical motor deficit in both RR-MS and P-MS. However, the CMCT was markedly prolonged in P-MS, when patients with similar clinical motor deficit and with similar disease duration were compared (p0.01). The differences were not attributable to differential involvement of the spinal cord, which was similar in RR-MS and P-MS.Our results disclose differences between the central motor conduction in RR-MS and P-MS that are not related to disease severity, spinal cord involvement or disease duration.
- Published
- 2003
17. The triple stimulation technique to study central motor conduction to the lower limbs
- Author
-
Kai M. Rösler, André Truffert, Michel R. Magistris, Christian W. Hess, and R Bühler
- Subjects
Adult ,Male ,medicine.medical_specialty ,Multiple Sclerosis ,medicine.medical_treatment ,Neural Conduction ,Pyramidal Tracts ,Central nervous system disease ,Muscular Diseases ,Physiology (medical) ,Internal medicine ,medicine ,Humans ,Motor Neuron Disease ,Amyotrophic lateral sclerosis ,Muscle, Skeletal ,Motor Neurons ,Leg ,business.industry ,Motor control ,Middle Aged ,Motor neuron ,Evoked Potentials, Motor ,bacterial infections and mycoses ,medicine.disease ,Electric Stimulation ,Sensory Systems ,Motor unit ,Transcranial magnetic stimulation ,medicine.anatomical_structure ,Spinal Cord ,Neurology ,Corticospinal tract ,Cardiology ,Female ,Neurology (clinical) ,business ,Neuroscience ,Motor cortex - Abstract
Objective : To quantify the percentage of motor units of a foot muscle that can be activated by transcranial magnetic stimulation (TMS) in normal subjects and patients. Methods : We adapted the recently described triple stimulation technique (TST) for recordings from abductor hallucis (AH). Conventional motor evoked potentials (MEPs) of this muscle are usually small and variable in shape, because of an important temporal desynchronization of the TMS induced spinal motor neuron discharges. The TST allows ‘resynchronization’ of these discharges and thereby a quantification of the proportion of motor units activated by TMS. The lower limb (LL-) TST was applied to 33 sides of 18 normal subjects and 51 sides of 46 patients with multiple sclerosis, amyotrophic lateral sclerosis, or spinal cord disorders. Results : In healthy subjects, the LL-TST demonstrated that TMS achieves activation of virtually all motor neurons supplying the AH. In 33 of 51 patient sides, abnormal LL-TST responses suggested corticospinal conduction failures of various degrees. The LL-TST was 2.54 times more sensitive to detect central conduction failures than the conventional LL-MEPs. Combining the LL-TST with TST of the upper limbs further increased the sensitivity to detect a conduction failure by 1.50 times. Conclusion : The LL-TST markedly improves the examination of corticospinal pathways.
- Published
- 2001
18. Quantification of upper motor neuron loss in amyotrophic lateral sclerosis
- Author
-
Michel R. Magistris, André Truffert, Kai M. Rösler, and Christian W. Hess
- Subjects
Adult ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,Neural Conduction ,Action Potentials ,Lower motor neuron ,Magnetics ,Physiology (medical) ,Internal medicine ,medicine ,Humans ,Amyotrophic lateral sclerosis ,Motor Neurons ,business.industry ,Upper motor neuron ,Muscles ,Amyotrophic Lateral Sclerosis ,Muscle weakness ,Anatomy ,Motor neuron ,medicine.disease ,Sensory Systems ,Motor unit ,Transcranial magnetic stimulation ,medicine.anatomical_structure ,Neurology ,Cardiology ,Female ,Neurology (clinical) ,medicine.symptom ,business ,Motor cortex - Abstract
Objective : To quantitatively estimate upper motor neuron (UMN) loss in ALS. Methods : We used the recently developed triple stimulation technique (TST) to study corticospinal conduction to 86 abductor digiti minimi muscles of 48 ALS patients. This method employs a collision technique to estimate the proportion of motor units activated by a transcranial magnetic stimulus. At the same time, it yields an estimate of lower motor neuron (LMN) integrity. Results : The TST disclosed and quantified central conduction failures attributable to UMN loss in 38 sides of 24 patients (subclinical in 15 sides), whereas conventional motor evoked potentials detected abnormalities in only 18 sides of 12 patients (subclinical in two sides). The increased sensitivity of the TST to detect UMN dysfunction was particularly observed in early cases. Increased central motor conduction times (CMCT) occurred exclusively in sides with conduction failure. In sides with clinical UMN syndromes, the TST response size (but not the CMCT) correlated with the muscle weakness. In sides with clinical LMN syndromes, the size of the peripherally evoked compound muscle action potentials correlated with the muscle weakness. Conclusion : The TST is a sensitive method to detect UMN dysfunction in ALS. It allows a quantitative estimate of the UMN loss, which is related to the functional deficit. Therefore, the TST has a considerable impact on diagnostic certainty in many patients. It will be suited to follow the disease progression and therapeutic trials.
- Published
- 2000
19. Polyneuropathy attributes: a comparison between patients with anti-MAG and anti-sulfatide antibodies
- Author
-
Andreas J. Steck, C. W. Hess, Thierry Kuntzer, Peter Fuhr, Roman Sztajzel, Julien Bogousslavsky, Kai M. Rösler, F. Ferracin, and Stefan Erb
- Subjects
Male ,Paraproteinemia ,Pathology ,medicine.medical_specialty ,Ataxia ,Myelin ,medicine ,Humans ,Aged ,Aged, 80 and over ,biology ,Myelin-associated glycoprotein ,business.industry ,Peripheral Nervous System Diseases ,Hyporeflexia ,Middle Aged ,medicine.disease ,Electrophysiology ,Motor Skills Disorders ,Myelin-Associated Glycoprotein ,Peripheral neuropathy ,medicine.anatomical_structure ,Immunoglobulin M ,nervous system ,Neurology ,Chronic Disease ,Disease Progression ,biology.protein ,Female ,Neurology (clinical) ,medicine.symptom ,Antibody ,business ,Polyneuropathy - Abstract
Thirty-two patients with a peripheral neuropathy and paraproteinemia were tested for IgM antibodies against myelin-associated protein (MAG) and sulfatide by means of enzyme-linked immunosorbent assay. Nine patients (28 %) had increased anti-sulfatide IgM antibodies and showed a chronic, slowly progressive, distally pronounced, and symmetric polyneuropathy with sensory to sensory-motor impairment, ataxia, hyporeflexia, and axonal involvement in electrophysiological studies. Ten patients (31 %) with increased anti-MAG antibodies had a similar, homogeneous polyneuropathy syndrome but presented with demyelinating features. A weak cross-reactivity between anti-MAG and anti-sulfatide antibodies was present in only three patients. In conclusion, although the two neuropathy groups clearly differed in their electrophysiological features, their clinical presentation was rather similar.
- Published
- 2000
20. Amyotrophic lateral sclerosis versus cervical spondylotic myelopathy: a study using transcranial magnetic stimulation with recordings from the trapezius and limb muscles
- Author
-
André Truffert, Michel R. Magistris, and Kai M. Rösler
- Subjects
Adult ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,Neural Conduction ,Diagnosis, Differential ,Spinal Osteophytosis ,Central nervous system disease ,Physical medicine and rehabilitation ,Degenerative disease ,Reference Values ,Physiology (medical) ,medicine ,Humans ,Motor Neuron Disease ,Amyotrophic lateral sclerosis ,Muscle, Skeletal ,Aged ,Aged, 80 and over ,business.industry ,Middle Aged ,Evoked Potentials, Motor ,medicine.disease ,Transcranial Magnetic Stimulation ,Sensory Systems ,Surgery ,body regions ,Transcranial magnetic stimulation ,Electrophysiology ,medicine.anatomical_structure ,Neurology ,Arm ,Cervical Vertebrae ,Female ,Neurology (clinical) ,business ,Trapezius muscle ,Motor cortex ,Cervical vertebrae - Abstract
Objective : We report an electrophysiological method to differentiate amyotrophic lateral sclerosis (ALS) from cervical spondylotic myelopathy (CSM). Methods : Motor evoked potentials (MEPs) by transcranial magnetic stimulation were investigated in patients with ALS ( n =10) and CSM ( n =9). In addition to limb MEPs using the triple stimulation technique (TST) at upper limbs, MEPs recorded from trapezius muscles were compared with those obtained from 23 normal subjects. The parameters studied were: central motor conduction time, amplitude ratio and, for the trapezius, the interside asymmetry. Results : Whereas limb MEPs were abnormal in most ALS and CSM patients (17/19), trapezius MEPs were abnormal in all ALS patients, and normal in 8 out of 9 CSM patients. Conclusion : Recording of trapezius MEPs is a valuable addition to the limb MEPs study, since it distinguishes ALS from SCM in most patients.
- Published
- 2000
21. Transcranial stimulation excites virtually all motor neurons supplying the target muscle. A demonstration and a method improving the study of motor evoked potentials
- Author
-
Michel R. Magistris, J P Myers, André Truffert, and Kai M. Rösler
- Subjects
Nervous system ,business.industry ,Stimulation ,Depolarization ,Stimulus (physiology) ,Peripheral ,medicine.anatomical_structure ,Cerebral cortex ,Corticospinal tract ,Medicine ,Neurology (clinical) ,Evoked potential ,business ,Neuroscience - Abstract
Transcranial stimulation has become an established method in the evaluation of corticospinal tract function. Clinical studies mainly address slowing of conduction through measurement of increased central conduction time (CCT) and 'failures' of conduction through observation of marked reductions in the size of the motor evoked potential (MEP). While CCT is of great interest in detecting subclinical slowing of conduction, the method discloses only gross failures of conduction, since the size of the MEP varies markedly between normal subjects and from one stimulus to another, leading to a broad range of normal values. Furthermore, transcranial stimulation does not appear to achieve depolarization of all spinal motor neurons leading to the target muscles, since in most normal subjects MEPs are smaller in amplitude than the responses evoked by peripheral nerve stimulation. We have developed a triple stimulation technique (TST) which, through two collisions, links central to peripheral conduction and suppresses desynchronization of MEPs. This technique shows that transcranial stimulation does achieve depolarization of all, or nearly all, spinal motor neurons supplying the target muscle in healthy subjects. Our data thus demonstrate that the amplitudes of MEPs are (i) smaller than those of peripheral responses, mostly due to phase cancellation of the action potentials caused by the desynchronization occurring within the corticospinal tract or at spinal cell level and (ii) variable between normal subjects and from one stimulus to another, mostly due to variability of this desynchronization. This technique provides new insights into normal corticospinal tract conduction. It will improve detection and quantification of central motor conduction failures.
- Published
- 1998
22. Swiss national guideline for reimbursement of enzyme replacement therapy in late-onset Pompe disease
- Author
-
Lukas Kern, Thomas Hundsberger, Kai M. Rösler, Marianne Rohrbach, University of Zurich, and Hundsberger, Thomas
- Subjects
Pediatrics ,medicine.medical_specialty ,congenital, hereditary, and neonatal diseases and abnormalities ,Cost effectiveness ,Cardiomyopathy ,Guidelines as Topic ,610 Medicine & health ,Disease ,Rare Diseases ,Cost of Illness ,Glycogen storage disease type II ,medicine ,Humans ,Enzyme Replacement Therapy ,Age of Onset ,Aged ,business.industry ,Glycogen Storage Disease Type II ,Prescription Fees ,Guideline ,Enzyme replacement therapy ,medicine.disease ,Insurance, Pharmaceutical Services ,Surgery ,2728 Neurology (clinical) ,Neurology ,10036 Medical Clinic ,2808 Neurology ,Acid alpha-glucosidase ,Female ,Neurology (clinical) ,Age of onset ,Glucan 1,4-alpha-Glucosidase ,business ,Switzerland - Abstract
Glycogen storage disease type II is a rare multi-systemic disorder characterised by an intracellular accumulation of glycogen due a mutation in the acid alpha glucosidase (GAA) gene. The level of residual enzyme activity, the genotype and other yet unknown factors account for the broad variation of the clinical phenotype. The classical infantile form is characterised by severe muscle hypotonia and cardiomyopathy leading to early death. The late-onset form presents as a limb girdle myopathy with or without pulmonary dysfunction. Enzyme replacement therapy (ERT) with recombinant human GAA (rhGAA) in infants is life saving. In contrast, therapeutic efficacy of rhGAA in the late-onset form is modest. High expenses of rhGAA, on-going infusions and poor pharmacokinetic efficacy raised a discussion of the cost effectiveness of ERT in late-onset Pompe disease in Switzerland. This discussion was triggered by a Swiss federal court ruling which confirmed the reluctance of a health care insurer not to reimburse treatment costs in a 67-year-old female suffering from Pompe disease. As a consequence of this judgement ERT was stopped by all insurance companies in late-onset Pompe patients in Switzerland regardless of their clinical condition. Subsequent negotiations lead to the release of a national guideline of the management of late-onset Pompe disease. Initiation and limitation of ERT is outlined in a national Pompe registry. Reimbursement criteria are defined and individual efficacy of ERT with rhGAA is continuously monitored.
- Published
- 2013
23. Electrophysiological characteristics of lesions in facial palsies of different etiologies. A study using electrical and magnetic stimulation techniques
- Author
-
Günther Deuschl, Kai M. Rösler, F.X. Glocker, Michel R. Magistris, Christian W. Hess, and A. Kohler
- Subjects
Adult ,Male ,Pathology ,medicine.medical_specialty ,Facial Paralysis ,Neural Conduction ,Electromyography ,Magnetics ,Bell's palsy ,medicine ,Axonotmesis ,Humans ,Cranial nerve disease ,Aged ,Analysis of Variance ,Palsy ,medicine.diagnostic_test ,business.industry ,General Neuroscience ,Middle Aged ,medicine.disease ,Facial nerve ,Electric Stimulation ,Facial paralysis ,medicine.anatomical_structure ,Female ,Neurology (clinical) ,medicine.symptom ,business ,Neuroscience ,Motor cortex - Abstract
Using magnetic stimulation techniques in addition to conventional electrical stimulation, the entire facial motor pathway can be assessed electrophysiologically. To study the diagnostic yield of these examinations, 174 patients with facial palsies of a variety of etiologies were examined (85 Bell's palsies, 24 Guillain-Barré syndrome (GBS), 19 Lyme borreliosis, 17 zoster oticus, 12 meningeal affections, 10 brain-stem disorders and 7 HIV-related facial palsies). The facial nerve was stimulated electrically at the stylomastoid fossa and magnetically within its canalicular portion. Additionally, the face-associated contralateral motor cortex was stimulated magnetically. Recordings were from the nasalis or mentalis muscle, or both, using surface electrodes. Bell's palsy patients showed typically a unilateral local hypoexcitability of the facial nerve to canalicular stimulation. In GBS, bilateral latency prolongations were frequent, as expected for a myelinic disorder. In contrast, in zoster, predominant axonotmesis was unilateral, and in HIV infection sometimes bilateral. The method was very sensitive to detect subclinical dysfunctions in meningo-radiculitis and malignant meningeal diseases, either prior to the onset of palsy, or on the contralateral (clinically unaffected) side. It also distinguished reliably between central and peripheral facial motor pathway lesions. In our experience, these inexpensive and non-invasive electrophysiological techniques contribute substantially to the differential diagnosis of facial palsies.
- Published
- 1995
24. Sensitivity and specificity of needle electromyography: a prospective study comparing automated interference pattern analysis with single motor unit potential analysis
- Author
-
Christian W. Hess, Kai M. Rösler, and Arto C. Nirkko
- Subjects
Adult ,Male ,Adolescent ,Electrodiagnosis ,Electromyography ,Sensitivity and Specificity ,Text mining ,Muscular Diseases ,medicine ,Humans ,Prospective Studies ,Potential analysis ,Prospective cohort study ,Aged ,Needle electromyography ,Aged, 80 and over ,medicine.diagnostic_test ,business.industry ,Muscles ,General Neuroscience ,Reproducibility of Results ,Middle Aged ,Motor unit ,Female ,Neurology (clinical) ,Nuclear medicine ,business ,Sensitivity (electronics) - Abstract
In this prospective study, automated interference pattern analysis (IPA, "Willison analysis", modified by Stålberg et al. 1983) was compared to the quantitative evaluation of mean motor unit potential duration (QMUP) in 239 muscles from consecutive, unselected patients. The sensitivity and specificity of both methods were calculated with respect to the clinically derived final neurological diagnosis, with histology available for 120 examinations. Whereas specificities were not different for the methods, the sensitivity for detection of abnormal vs. normal was 49% for QMUP and 74% for IPA (P0.001). The sensitivity for detection of myopathy or neuropathy was 46% or 38% for QMUP and 75% (P0.001) or 53% (P0.05) for IPA. Thus, in all instances, IPA had superior sensitivity with unchanged specificity as compared to QMUP. The results of a rapid and purely qualitative visual MUP assessment were statistically not different from QMUP. Although widely used, neither of these methods has been evaluated for its reliability in unselected patients with various grades of disease. Our results indicate that in a routine setting, the best diagnostic strategy might be the automated IPA, which can be quickly obtained in several muscles, followed by muscle biopsy in unclear cases.
- Published
- 1995
25. Corticospinal output during muscular fatigue differs in multiple sclerosis patients compared to healthy controls
- Author
-
Kai M. Rösler, Sebastian Humpert, Olivier Scheidegger, and Christian P. Kamm
- Subjects
Adult ,Male ,medicine.medical_specialty ,Multiple Sclerosis ,Adolescent ,medicine.medical_treatment ,Neural Conduction ,Pyramidal Tracts ,Stimulation ,Young Adult ,Physical medicine and rehabilitation ,Internal medicine ,medicine ,Humans ,In patient ,Young adult ,Muscle fatigue ,business.industry ,Multiple sclerosis ,Middle Aged ,medicine.disease ,Evoked Potentials, Motor ,Transcranial Magnetic Stimulation ,Transcranial magnetic stimulation ,Neurology ,Muscular fatigue ,Muscle Fatigue ,Cardiology ,Female ,Neurology (clinical) ,medicine.symptom ,business ,Muscle contraction ,Muscle Contraction - Abstract
Background: In multiple sclerosis (MS), fatigue is a common and often disabling symptom. It has multiple causes with central motor fatigue playing an important role. Objective: The objective of this study was to analyse the central motor conduction changes in relation to muscle contraction force during muscle fatigue and recovery in MS patients compared to healthy controls. Methods: A total of 23 MS patients with fatigue and 13 healthy subjects were assessed during 2 minutes of fatiguing exercise of the abductor digiti minimi muscle of the hand and the subsequent 7 minutes of recovery. Central motor conduction was quantified by transcranial magnetic stimulation using the triple stimulation protocol and calculating a central conduction index (CCI). Results: Force declined to 36% of the pre-exercise level (SD 16%; p < 0.01) in MS patients and to 44% (SD 9%, p < 0.01) in healthy subjects (group differences, not statistically significant). The decline of the CCI was significantly less marked in patients (–20%, SD 26%, p < 0.05) than in healthy subjects (–57%, SD 15%, p < 0.05; group differences, p < 0.05). The decline of force and CCI were not correlated in either group. Conclusions: During a fatiguing exercise, the decline in central motor conduction is significantly less pronounced in MS patients than healthy subjects, although the reduction of force is similar.
- Published
- 2012
26. Assessment of motor pathways to masticatory muscles: An examination technique using electrical and magnetic stimulation
- Author
-
Ülkü Türk, Johannes Mathis, Kai M. Rösler, Wolf Müllbacher, and Christian W. Hess
- Subjects
Trigeminal nerve ,Physiology ,business.industry ,Magnetic resonance neurography ,Motor nerve ,Anatomy ,medicine.disease ,Facial nerve ,Masticatory force ,Cellular and Molecular Neuroscience ,medicine.anatomical_structure ,Trigeminal neuralgia ,Physiology (medical) ,Neuralgia ,Medicine ,Zygomatic arch ,Neurology (clinical) ,business - Abstract
To study motor pathways to masticatory muscles, a new recording technique using surface electrodes was developed. The recording electrode was mounted on a spatula and inserted enorally into the pterygomandibular plica over the belly of m. masseter. Using this technique, mean latencies/amplitudes of the compound action potentials (CMAPs) in 18 healthy subjects were 1.2 ms/4.9 mV after electrical stimulation of the trigeminal nerve below the zygomatic arch, and 5.5 ms/1.1 mV after magnetic stimulation of the cortex. In 15 patients with unilateral lesions of the facial nerve, masticatory CMAPs had virtually symmetrical configuration, latency, and amplitude, excluding a major contribution of volume conducted activity from other cranial muscles. The technique was evaluated in patients after surgical treatment for trigeminal neuralgia. Patients with with retrogasserian thermocoagulation and central demyelinating lesions were consistently identified. © 1994 John Wiley & Sons, Inc.
- Published
- 1994
27. Motor-Evoked Responses to Transcranial Brain Stimulation Persist During Cataplexy: A Case Report
- Author
-
Arto C. Nirkko, Kai M. Rösler, Christian W. Hess, and Rihs F
- Subjects
Male ,Cataplexy ,Rapid eye movement sleep ,Neuromuscular transmission ,Action Potentials ,Magnetics ,Muscle tone ,Tibialis anterior muscle ,Physiology (medical) ,medicine ,Humans ,Narcolepsy ,business.industry ,Muscles ,Brain ,Middle Aged ,medicine.disease ,medicine.anatomical_structure ,Brain stimulation ,Neurology (clinical) ,medicine.symptom ,business ,Trapezius muscle ,Neuroscience - Abstract
Magnetic brain stimulation was performed in a patient with the narcolepsy-cataplexy syndrome during and after a cataplectic status. Amplitudes and thresholds of responses in six muscles (diaphragm, lumbar erector spinae, trapezius, biceps, tibialis anterior and abductor digiti V) remained unchanged during cataplexy as compared to the normal state. Our data suggest that, similar to rapid eye movement (REM) sleep, an enhanced cortical excitability to magnetic brain stimulation may compensate for the postsynaptic spinal inhibition of muscle tone during cataplexy, and that there is no difference in this respect between axial and distal muscles. Our data agree well with other evidence of increased cortex activity during cataplexy and REM sleep.
- Published
- 1994
28. Electrophysiological characterization of pre- and postoperative facial nerve function in patients with acoustic neuroma using electrical and magnetic stimulation techniques
- Author
-
Kai M. Rösler, Urs D. Schmid, Walther K. Jenni, and Christian W. Hess
- Subjects
medicine.medical_specialty ,Palsy ,Nasalis muscle ,medicine.diagnostic_test ,Physiology ,business.industry ,Magnetic resonance neurography ,Acoustic neuroma ,Electromyography ,Neuroma ,medicine.disease ,Facial nerve ,Facial paralysis ,Surgery ,Cellular and Molecular Neuroscience ,Physiology (medical) ,Anesthesia ,otorhinolaryngologic diseases ,Medicine ,Neurology (clinical) ,business - Abstract
Facial nerve function was examined in patients who underwent posterior fossa surgery for unilateral acoustic neuroma. Examinations took place prior to surgery (n = 47 patients), early after surgery (0-12 days, n = 16 of 47 patients), and late after surgery (187-1505 days, n = 29 of 47 patients). Clinical signs of facial palsy were present to a variable extent in 13 of 47 patients before, in 12 of 16 patients early, and in 18 of 29 patients later after surgery. Electrophysiologically, the facial nerve was stimulated electrically at the stylomastoid fossa and magnetically at its proximal intracanalicular segment. In addition, the face-associated motor cortex was stimulated magnetically. In patients with facial palsy, any of these stimulation methods resulted in a decreased amplitude of the response in the nasalis muscle. The decrease showed a linear relationship to the clinical grade of palsy, pre- and postoperatively. Corticomuscular latencies remained unchanged. We conclude that: (i) the electrophysiological characteristics of facial nerve lesions due to compression by acoustic neuromas or due to a complication of neuroma removal are those of a purely axonal neuropathy; (ii) the three stimulation techniques have a similar diagnostic yield, thus making the use of all three of them redundant; and (iii) the electrophysiological techniques allowed no prediction of the final facial nerve function.
- Published
- 1994
29. Basic mechanisms
- Author
-
Kai M. Rösler and Christian W. Hess
- Subjects
Solifenacin ,business.industry ,Multiple sclerosis ,Disease progression ,Oligoclonal banding ,medicine.disease ,Atropine ,Methylprednisolone ,Anesthesia ,Edema ,medicine ,medicine.symptom ,business ,Cognitive impairment ,medicine.drug - Published
- 2010
30. Sciatic neuropathy after body contouring surgery in massive weight loss patients
- Author
-
Kai M. Rösler, Andrej Banic, David Kiermeir, and Dominique Erni
- Subjects
Adult ,Foot drop ,Sciatic Neuropathy ,medicine.medical_specialty ,medicine.medical_treatment ,Population ,Dermatologic Surgical Procedures ,Bariatric Surgery ,Young Adult ,Weight loss ,Weight Loss ,medicine ,Humans ,education ,education.field_of_study ,Wound Healing ,Abdominoplasty ,business.industry ,Electromyography ,Abdominal Wall ,Plastic Surgery Procedures ,Surgery ,Body contouring surgery ,Obesity, Morbid ,Thigh ,Anesthesia ,Body contouring ,Female ,Sciatic nerve ,medicine.symptom ,business ,Follow-Up Studies - Abstract
To date, obesity affects a substantial population in industrialised countries. Due to the increased awareness of obesity-related morbidity, efficient dietary regimens and the recent successes with bariatric surgery, there is now a high demand for body contouring surgery to correct skin abundancies after massive weight loss. The known risks for this type of surgery are mainly wound-healing complications, and, more rarely, thromboembolic or respiratory complications. We present two female patients (23 and 39 years of age) who, in spite of standard positioning and precautions, developed sciatic neuropathy after combined body contouring procedures, including abdominoplasty and inner thigh lift. Complete functional loss of the sciatic nerve was found by clinical and electroneurographic examination on the left side in patient one and bilaterally in patient two. Full nerve conductance recovery was obtained after 6 months in both patients. Although the occurrence of spontaneous neuropathies after heavy weight loss is well documented, this is the first report describing the appearance of such a phenomenon following body contouring surgery. One theoretical explanation may be the compression of the nerve during the semirecumbent positioning combined with hip flexion and abduction, which was required for abdominal closure and simultaneous access to the inner thighs. We advise to avoid this positioning and to include the risk of sciatic neuropathy in the routine preoperative information of patients scheduled for body contouring surgery after heavy weight loss.
- Published
- 2009
31. Motor-evoked potential changes during human muscular fatigue – A triple stimulation technique study
- Author
-
L. Firmin, Kai M. Rösler, and Olivier Scheidegger
- Subjects
business.industry ,Stimulation technique ,Physiology (medical) ,Muscular fatigue ,Medicine ,Neurology (clinical) ,Evoked potential ,business ,Neuroscience - Published
- 2009
32. Supramaximal excitation of the brachial plexus by percutaneous monopolar stimulation
- Author
-
L. Firmin, S. Humpert, and Kai M. Rösler
- Subjects
Percutaneous ,business.industry ,Physiology (medical) ,Anesthesia ,Medicine ,Neurology (clinical) ,Monopolar stimulation ,business ,Brachial plexus - Published
- 2008
33. Ultrasound-guided sensory needle neurography of the sural nerve
- Author
-
Olivier Scheidegger, Christian P. Kamm, and Kai M. Rösler
- Subjects
business.industry ,Physiology (medical) ,Magnetic resonance neurography ,Medicine ,Sensory system ,Sural nerve ,Neurology (clinical) ,Nuclear medicine ,business ,Ultrasound guided - Published
- 2008
34. Long-Term Interruption of Enzyme Replacement Therapy with rhGAA in Pompe Disease Leads to Irreversible Clinical Decline
- Author
-
Oliver Findling, Thomas Hundsberger, and Kai M. Rösler
- Subjects
Drug supply ,congenital, hereditary, and neonatal diseases and abnormalities ,medicine.medical_specialty ,business.industry ,nutritional and metabolic diseases ,Enzyme replacement therapy ,Disease ,humanities ,Neurology ,Federal court ,medicine ,Neurology (clinical) ,Intensive care medicine ,Treatment costs ,business ,Alglucosidase alfa ,medicine.drug - Abstract
Enzyme replacement therapy (ERT) with recombinant human alglucosidase alfa (rhGAA) in Pompe disease is moderately effective and a life-long therapy is warranted. Clinical investigations of temporary ERT interruption are lacking, but might be of clinical signifi cance (i.e. due to patient’s wish, adherence issues, holidays, or problems with drug supply). In Switzerland, ERT for Pompe disease was interrupted after the federal court judged that the treatment costs for adults were greatly out of proportion. Retreatment was initiated after therapy was fi nally licensed.
- Published
- 2015
35. Muscle metabolites: functional MR spectroscopy during exercise imposed by tetanic electrical nerve stimulation
- Author
-
Johannes Slotboom, Arto C. Nirkko, and Kai M. Rösler
- Subjects
Adult ,Male ,Nerve stimulation ,medicine.medical_specialty ,Magnetic Resonance Spectroscopy ,Phosphocreatine ,Metabolite ,Stimulation ,chemistry.chemical_compound ,Internal medicine ,medicine ,Functional mr ,Humans ,Radiology, Nuclear Medicine and imaging ,Repetitive nerve stimulation ,Prospective Studies ,Acetylcarnitine ,Exercise ,medicine.diagnostic_test ,business.industry ,Muscles ,Magnetic resonance imaging ,Middle Aged ,Creatine ,Electric Stimulation ,chemistry ,Cardiology ,business ,Nuclear medicine ,medicine.drug ,Muscle Contraction - Abstract
Permission from the ethics committee and informed consent were obtained. The purpose of this study was to prospectively evaluate a method developed for the noninvasive assessment of muscle metabolites during exercise. Hydrogen 1 magnetic resonance (MR) spectroscopy peaks were measured during tetanic isometric muscle contraction imposed by supramaximal repetitive nerve stimulation. The kinetics of creatine-phosphocreatine and acetylcarnitine signal changes (P < .001) could be assessed continuously before, during, and after exercise. The control peak (trimethylammonium compounds), which served as an internal reference, did not change. This technique-that is, functional MR spectroscopy-opens the possibility for noninvasive diagnostic muscle metabolite testing in a clinical setting.
- Published
- 2006
36. Quantification of central motor conduction deficits in multiple sclerosis patients before and after treatment of acute exacerbation by methylprednisolone
- Author
-
Werner J. Z’Graggen, A.M. Humm, Robert Bühler, Kai M. Rösler, and Michel R. Magistris
- Subjects
Adult ,Male ,Paper ,medicine.medical_specialty ,Optic Neuritis ,Exacerbation ,Neural Conduction ,Pyramidal Tracts ,Methylprednisolone ,Central nervous system disease ,Multiple Sclerosis, Relapsing-Remitting ,Isometric Contraction ,Motor system ,medicine ,Humans ,Optic neuritis ,Motor Neuron Disease ,Infusions, Intravenous ,Muscle, Skeletal ,Pyramidal tracts ,Dose-Response Relationship, Drug ,business.industry ,Multiple sclerosis ,Middle Aged ,Multiple Sclerosis, Chronic Progressive ,medicine.disease ,Evoked Potentials, Motor ,Surgery ,Psychiatry and Mental health ,medicine.anatomical_structure ,Treatment Outcome ,Anesthesia ,Female ,Neurology (clinical) ,business ,medicine.drug - Abstract
To compare the effects of intravenous methylprednisolone (IVMP) in patients with relapsing-remitting (RR-MS), secondary progressive (SP-MS), and primary progressive multiple sclerosis (PP-MS).Clinical and neurophysiological follow up was undertaken in 24 RR-MS, eight SP-MS, and nine PP-MS patients receiving Solu-Medrol 500 mg/d over five days for exacerbations involving the motor system. Motor evoked potentials (MEPs) were used to measure central motor conduction time (CMCT) and the triple stimulation technique (TST) was applied to assess conduction deficits. The TST allows accurate quantification of the number of conducting central motor neurones, expressed by the TST amplitude ratio.There was a significant increase in TST amplitude ratio in RR-MS (p0.001) and SP-MS patients (p0.02) at day 5, paralleling an increase in muscle force. TST amplitude ratio and muscle force remained stable at two months. In PP-MS, TST amplitude ratio and muscle force did not change. CMCT did not change significantly in any of the three groups.In RR-MS and SP-MS, IVMP is followed by a prompt increase in conducting central motor neurones paralleled by improvement in muscle force, which most probably reflects partial resolution of central conduction block. The lack of similar clinical and neurophysiological changes in PP-MS corroborates previous clinical reports on limited IVMP efficacy in this patient group and points to pathophysiological differences underlying exacerbations in PP-MS.
- Published
- 2005
37. Significance of coil orientation for motor evoked potentials from nasalis muscle elicited by transcranial magnetic stimulation
- Author
-
Christian W. Hess, Johannes Mathis, Kai M. Rösler, Adrian G. Guggisberg, and Patrick Dubach
- Subjects
Adult ,Male ,Motor Cortex/physiology ,Nasalis muscle ,medicine.medical_treatment ,Neural Conduction ,Facial Muscles ,Stimulation ,Functional Laterality ,Functional Laterality/physiology ,Masseter muscle ,Physiology (medical) ,medicine ,Reaction Time ,Humans ,Facial Muscles/innervation/physiology ,Electric Stimulation/methods ,business.industry ,Neural Conduction/physiology ,Motor Cortex ,Motor control ,Anatomy ,Middle Aged ,Evoked Potentials, Motor ,Transcranial Magnetic Stimulation ,Sensory Systems ,Electric Stimulation ,Transcranial magnetic stimulation ,Facial muscles ,medicine.anatomical_structure ,Neurology ,Reaction Time/physiology ,Reflex ,Female ,Neurology (clinical) ,business ,Neuroscience ,Evoked Potentials, Motor/physiology ,Motor cortex - Abstract
OBJECTIVE: In transcranial magnetic stimulation (TMS) of the motor cortex, the optimal orientation of the coil on the scalp is dependent on the muscle under investigation, but not yet known for facial muscles. METHODS: Using a figure-of-eight coil, we compared TMS induced motor evoked potentials (MEPs) from eight different coil orientations when recording from ipsi- and contralateral nasalis muscle. RESULTS: The MEPs from nasalis muscle revealed three components: The major ipsi- and contra-lateral middle latency responses of approximately 10 ms onset latency proved entirely dependent on voluntary pre-innervation. They were most easily obtained from a coil orientation with posterior inducing current direction, and in this respect resembled the intrinsic hand rather than the masseter muscles. Early short duration responses of around 6 ms onset latency were best elicited with an antero-lateral current direction and not pre-innervation dependent, and therefore most probably due to stimulation of the nerve roots. Late responses (>18 ms) could inconsistently be elicited with posterior coil orientations in pre-innervated condition. CONCLUSIONS: By using the appropriate coil orientation and both conditions relaxed and pre-innervated, cortically evoked MEP responses from nasalis muscle can reliably be separated from peripheral and reflex components and also from cross talk of masseter muscle activation.
- Published
- 2003
38. Transcranial magnetic brain stimulation: a tool to investigate central motor pathways
- Author
-
Kai M. Rösler
- Subjects
medicine.medical_specialty ,Neuronal Plasticity ,Physical Education and Training ,Physiology ,business.industry ,medicine.medical_treatment ,Magnetic brain stimulation ,Brain ,Motor Activity ,Clinical neurophysiology ,Evoked Potentials, Motor ,Motor Pathways ,Electric Stimulation ,Transcranial magnetic stimulation ,Magnetics ,Cognition ,Neural Pathways ,Medicine ,Humans ,business ,Neuroscience - Abstract
Transcranial magnetic stimulation allows the painless activation of cortical motor neurons and elicits responses in a wide range of muscles, termed “motor-evoked potentials.” Since its introduction in 1985, the technique has evolved as one of the most fruitful recent contributions to clinical neurophysiology.
- Published
- 2001
39. Inhibitory conditioning stimulus in transcranial magnetic stimulation reduces the number of excited spinal motor neurons
- Author
-
Florian Heinen, Urban M. Fietzek, Rudolf Korinthenberg, Kai M. Rösler, Steffen Berweck, Volker Mall, and F.X. Glocker
- Subjects
Adult ,Male ,Wrist Joint ,medicine.medical_treatment ,Central nervous system ,Electromyography ,Stimulus (physiology) ,Reference Values ,Physiology (medical) ,Conditioning, Psychological ,Medicine ,Humans ,Muscle, Skeletal ,Motor Neurons ,Informed Consent ,medicine.diagnostic_test ,business.industry ,Motor control ,Motor neuron ,bacterial infections and mycoses ,Spinal cord ,Transcranial Magnetic Stimulation ,Sensory Systems ,Peripheral ,Transcranial magnetic stimulation ,medicine.anatomical_structure ,Neurology ,Spinal Cord ,Female ,Neurology (clinical) ,business ,Neuroscience - Abstract
Objective : To study the mechanisms of amplitude attenuation caused by a transcranial magnetic conditioning stimulus. Both conventional MEPs and the recently described triple stimulation technique (TST) were applied; the latter to improve the quantification of the response size decrease. Methods : TST uses a peripheral collision method to eliminate the effects of desynchronization of the transcranial magnetic stimulation (TMS) induced spinal motor neuron discharges. The attenuation of motor evoked potentials (MEPs) and responses to TST was studied in 10 healthy volunteers using the conditioning-test paradigm with 2 ms interstimulus intervals. Results : Conventional MEPs and responses to TST demonstrated a marked attenuation by the preceding conditioning stimulus in all subjects. The ratio of MEP to TST amplitudes was the same in conditioned and unconditioned responses. Conclusions : Our findings suggest that the transcranial conditioning stimulus does not change the degrees of desynchronization of spinal motor neuron discharges, but results in a reduced number of excited alpha motor neurons. This reduction can be estimated by both MEPs and TST.
- Published
- 2001
40. A bedside test to determine motion stereopsis using the Pulfrich phenomenon
- Author
-
Hans Oetliker, Daniel S. Mojon, and Kai M. Rösler
- Subjects
Adult ,Male ,medicine.medical_specialty ,Optic Neuritis ,Adolescent ,Point-of-Care Systems ,Motion Perception ,Pulfrich effect ,Audiology ,Diagnostic Techniques, Ophthalmological ,Spearman's rank correlation coefficient ,Sensitivity and Specificity ,Correlation ,Perceptual Disorders ,Optics ,Bedside test ,Medicine ,Humans ,Visual Pathways ,Normal range ,Depth Perception ,Perceptual Distortion ,business.industry ,Outcome measures ,Reproducibility of Results ,Middle Aged ,Illusions ,Ophthalmology ,Stereopsis ,Acute Disease ,Female ,business ,Neutral density filter - Abstract
Many diseases induce asymmetric delays in the visual pathway, resulting in a spontaneous Pulfrich phenomenon (PP). The PP is a visual stereoillusion that may cause difficulties in persons when traveling in cars, crossing the road, or playing ball games. The authors developed and tested a simple new bedside procedure to detect PP.A case series.Disease simulation in 2 normal subjects and 18 patients with optic neuritis (ON) was examined. Ninety normal subjects were studied to determine normal range of PP.The new test, called swinging pen test (SPT), is performed by oscillating a pen by hand. The SPT was compared to a gold standard, a mechanical pendulum (MP).The authors measured simulated PP in two normal subjects and PP in 18 patients with ON and 90 normal control subjects. The Pearson product-moment correlation (r) and the Spearman rank correlation (rs) between SPT and MP were calculated.The magnitudes of simulated PP determined with the SPT and the MP correlated well (r = 0.92, P0.005, and r = 0.96, P0.001). Correlation also was good in patients with ON (rs = 0.90, P0.05). The positive predictive value of the SPT was 100%, and the negative predictive value was 92%. The PP was absent in all control subjects testing with either pendulum. The normal range for PP varied from -1.40 to 1.52 msec. For the SPT, the intraobserver variability coefficient was 8.2%, and the interobserver variability coefficient was 10.5%.The authors believe that SPT will be of value to clinicians on bedside evaluation of motion stereopsis dysfunctions. The normal range of PP was approximately +/- -1.5 msec (approximately +/- -1.5 cm), corresponding to a 0.3-log unit neutral density filter).
- Published
- 1998
41. Electrical Stylomastoidal and Magnetic Transcranial Stimulation of the Facial Nerve in Bell’s Palsy: Time Course of Electrophysiological Parameters
- Author
-
Kai M. Rösler, Ch. W. Hess, F.X. Glocker, and Michel R. Magistris
- Subjects
Palsy ,business.industry ,Stimulation ,medicine.disease ,Facial nerve ,Compound muscle action potential ,Electrophysiology ,medicine.anatomical_structure ,Anesthesia ,Cortex (anatomy) ,Bell's palsy ,medicine ,Mentalis ,business - Abstract
Facial nerve motor neurographies were performed at various time intervals after onset of Bell’s palsy in 75 patients. Amplitudes and onset latencies of the compound muscle action potential (CMAP) of m. nasalis and/or mentalis were measured after electrical extracranial (fossa stylomastoidea; ElStim) and magnetic transcranial (intracranial; MagStim) stimulation of the facial nerve, and in some patients also after magnetic cortex stimulation. Onset latencies were on average slightly increased on the side of the palsy: MagStim 109.8% (SD 19.8), ElStim 107.2% (SD 15.2). The time course of CMAP amplitudes was characterized by an early and marked reduction after MagStim as compared to ElStim (in 68% of patients MagStim evoked no response). Mean amplitudes (as percentages of the healthy side) versus days of palsy were
- Published
- 1994
42. The effect of ketamine anesthetic induction on muscle responses to transcranial magnetic cortex stimulation studied in man
- Author
-
U. D. Schmid, Karl Kothbauer, Kai M. Rösler, and Susanne Liechti
- Subjects
Adult ,Male ,Dose ,Stimulation ,Anesthetic Agent ,Magnetics ,Physical Stimulation ,medicine ,Humans ,Ketamine ,Evoked Potentials ,Cerebral Cortex ,Pyramidal tracts ,business.industry ,General Neuroscience ,Muscles ,Motor Cortex ,Middle Aged ,medicine.anatomical_structure ,Cerebral cortex ,Anesthesia ,Anesthetic ,Anesthesia, Intravenous ,Female ,business ,Motor cortex ,medicine.drug - Abstract
In man, an anesthetic agent that induces surgical anesthesia with minimal influence on descending pyramidal tract activity remains to be found. Anesthesia with ketamine allows recording of stable compound muscle action potentials (CMAPs) to single transcranial magnetic stimulations of the motor cortex (CortStim) in monkeys. This report describes the findings in 5 patients, where CMAPs to CortStim were recorded from the right hypothenar during anesthesia induction with ketamine. The agent was injected intravenously every 90 s in 6 steps of 0.5 mg up to a maximum of 3 mg/kg body weight (BW). Surgical anesthesia was achieved after ketamine injection of 1.5 (n = 4 patients) or 2.0 mg/kg BW (n = 1). In the five individuals tested, CMAP amplitudes and latencies (mean; range) were 2.6 (1.6-5.8) mV and 22.8 (20.4-24.6) ms before induction, and 1.6 (0.3-4.7) mV and 23.5 (21.7-24.5) ms after administration of the maximum dose. The paired differences (mean +/- 1 S.D.) were 0.8 +/- 0.6 mV and 1.0 +/- 0.8 ms and were statistically not significant (n = 5, P = 0.1, Wilcoxon-test). With ketamine as a single anesthetic induction agent CMAPs to single CortStim remain easily recordable even in dosages higher than those necessary to induce surgical anesthesia. All other previously tested anesthetic agents suppress CMAPs to CortStim as soon as the patient is unconscious.
- Published
- 1993
43. The Pulfrich phenomenon: Authors’ reply
- Author
-
Hans Oetliker, Daniel S. Mojon, and Kai M Rösler
- Subjects
Ophthalmology ,Psychoanalysis ,business.industry ,Phenomenon ,Medicine ,business - Published
- 1999
44. 4. Supramaximal excitation of the brachial plexus by percutaneous monopolar stimulation
- Author
-
Kai M. Rösler, S. Humpert, and L. Firmin
- Subjects
Percutaneous ,Neurology ,business.industry ,Physiology (medical) ,Anesthesia ,Medicine ,Neurology (clinical) ,Monopolar stimulation ,business ,Brachial plexus ,Sensory Systems - Published
- 2008
45. Repetitive spinal motor neuron discharges following single transcranial magnetic stimulation: Relation to handedness
- Author
-
Werner J. Z’Graggen, A.M. Humm, M. Hosang, S. Bachmann, and Kai M. Rösler
- Subjects
Transcranial magnetic stimulation ,medicine.anatomical_structure ,Neurology ,business.industry ,Physiology (medical) ,medicine.medical_treatment ,Medicine ,Neurology (clinical) ,Motor neuron ,business ,Neuroscience ,Sensory Systems - Published
- 2007
46. Electrophysiologic findings in multifocal motor neuropathy
- Author
-
Kai M. Rösler
- Subjects
medicine.medical_specialty ,Physical medicine and rehabilitation ,Text mining ,business.industry ,medicine ,Neurology (clinical) ,business ,medicine.disease ,Multifocal motor neuropathy - Published
- 1998
47. PS-54-5 Do quantitative EMG and muscle biopsy provide prognostic clues in amyotrophic lateral sclerosis?
- Author
-
Heinz Truffer, Christian W. Hess, Patrick Saudan, and Kai M. Rösler
- Subjects
Pathology ,medicine.medical_specialty ,Muscle biopsy ,medicine.diagnostic_test ,business.industry ,General Neuroscience ,medicine ,Neurology (clinical) ,Amyotrophic lateral sclerosis ,business ,medicine.disease - Published
- 1995
48. Multifocal motor neuropathy (MMN): clinical and electrophysiological observation in a patient before and during therapy with intravenous immunoglobulins (IVIG)
- Author
-
Christian W. Hess, S. Beer, Kai M. Rösler, M. Sturzenegger, and R. Baugmgartner
- Subjects
Electrophysiology ,Pathology ,medicine.medical_specialty ,business.industry ,Intravenous Immunoglobulins ,General Neuroscience ,Anesthesia ,medicine ,Mismatch negativity ,Neurology (clinical) ,business ,medicine.disease ,Multifocal motor neuropathy - Published
- 1995
49. Contribution of electrophysiological examinations to the differential diagnosis of facial palsies
- Author
-
F.X. Glocker, Michel R. Magistris, Kai M. Rösler, and Christian W. Hess
- Subjects
medicine.medical_specialty ,Electrophysiology ,business.industry ,General Neuroscience ,medicine ,Neurology (clinical) ,Radiology ,Differential diagnosis ,business - Published
- 1995
50. Time course of electrophysiological findings by electrical and magnetic stimulation of facial motor pathways in Bell's palsy
- Author
-
F.X. Glocker, Michel R. Magistris, Christian W. Hess, and Kai M. Rösler
- Subjects
medicine.medical_specialty ,business.industry ,General Neuroscience ,Stimulation ,Audiology ,medicine.disease ,Motor Pathways ,Electrophysiology ,Bell's palsy ,Time course ,medicine ,Neurology (clinical) ,business ,Neuroscience - Published
- 1993
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