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Background: Cortical plasticity induced by quadripulse stimulation (QPS) has been shown to correlate with cognitive functions in patients with relapsing-remitting multiple sclerosis (RRMS) and to not be reduced compared to healthy controls (HCs). Objective: This study aimed to compare the degree of QPS-induced plasticity between different subtypes of multiple sclerosis (MS) and HCs and to investigate the association of the degree of plasticity with motor and cognitive functions. We expected lower levels of plasticity in patients with progressive MS (PMS) but not RRMS compared to HCs. Furthermore, we expected to find positive correlations with cognitive and motor performance in patients with MS. Methods: QPS-induced plasticity was compared between 34 patients with PMS, 30 patients with RRMS, and 30 HCs using linear mixed-effects models. The degree of QPS-induced cortical plasticity was correlated with various motor and cognitive outcomes. Results: There were no differences regarding the degree of QPS-induced cortical plasticity between HCs and patients with RRMS (p = 0.86) and PMS (p = 0.18). However, we only found correlations between the level of induced plasticity and both motor and cognitive functions in patients with intact corticospinal tract integrity. Exploratory analysis revealed significantly reduced QPS-induced plasticity in patients with damage compared to intact corticospinal tract integrity (p < 0.001). Conclusion: Our study supports the notion of pyramidal tract integrity being of more relevance for QPS-induced cortical plasticity in MS and related functional significance than the type of disease. [ABSTRACT FROM AUTHOR]

Purpose: Deep brain stimulation (DBS), an effective treatment for movement disorders, usually involves lead implantation while the patient is awake and sedated. Recently, there has been interest in performing the procedure under general anesthesia (asleep). This report of a consecutive cohort of DBS patients describes anesthesia protocols for both awake and asleep procedures. Methods: Consecutive patients with Parkinson's disease received subthalamic nucleus (STN) implants either moderately sedated or while intubated, using propofol and remifentanil. Microelectrode recordings were performed with up to five trajectories after discontinuing sedation in the awake group, or reducing sedation in the asleep group. Clinical outcome was compared between groups with the UPDRS III. Results: The awake group (n = 17) received 3.5 mg/kg/h propofol and 11.6 μg/kg/h remifentanil. During recording, all anesthesia was stopped. The asleep group (n = 63) initially received 6.9 mg/kg/h propofol and 31.3 μg/kg/h remifentanil. During recording, this was reduced to 3.1 mg/kg/h propofol and 10.8 μg/kg/h remifentanil. Without parkinsonian medications or stimulation, 3-month UPDRS III ratings (ns = 16 and 52) were 40.8 in the awake group and 41.4 in the asleep group. Without medications but with stimulation turned on, ratings improved to 26.5 in the awake group and 26.3 in the asleep group. With both medications and stimulation, ratings improved further to 17.6 in the awake group and 15.3 in the asleep group. All within-group improvements from the off/off condition were statistically significant (all ps < 0.01). The degree of improvement with stimulation, with or without medications, was not significantly different in the awake vs. asleep groups (ps > 0.05). Conclusion: The above anesthesia protocols make possible an asleep implant procedure that can incorporate sufficient microelectrode recording. Together, this may increase patient comfort and improve clinical outcomes. [ABSTRACT FROM AUTHOR]

Objective: Motor evoked potentials (MEP), obtained by transcranial magnetic stimulation (TMS) are a common tool in clinical research and diagnostic. Nevertheless, reports regarding the influence of filter settings on MEP are sparse. Here, we compared MEP amplitudes and signal to noise ratio (SNR) using multiple high pass filter (HPF) and notch filter settings. Materials and Methods: Twenty healthy subjects were enrolled in the study. Recruitment curves were obtained with HPF settings varied at 10, 20, 50, and 100 Hz. The four HPF settings were tested both with and without 50 Hz active notch filter. Low pass filter was kept constant at 5 kHz. Results: MEP amplitudes with HPF at 10 and 20 Hz were significantly higher than at 100 Hz, regardless of the notch filter. However, SNR did not differ among HPF settings. An active notch filter significantly improved SNR. Conclusion: The reduction in MEP amplitudes with HPF above 20 Hz may be due to noise reduction, since the different HPF conditions did not alter SNR. Thus, higher HPF above 50 Hz may be an option to reduce noise, the use of a notch filter may even improve SNR. Significance: Our findings are relevant for the selection of filter settings and might be of importance to any researcher who utilizes TMS-MEP. [ABSTRACT FROM AUTHOR]

Conditioning transcranial magnetic stimulation (TMS) with subthreshold conditioning stimulus followed by supra-threshold test stimulus at inter-stimulus intervals (ISI) of 1–5 ms results in inhibition (SICI), while ISI at 10–15 ms results in facilitation (ICF). One concerning issue, applying ICF/SICI protocols on patients is the substantial protocol variability. Here, we hypothesized that increasing the number of CS could result in more robust ICF/SICI protocols. Twenty healthy subjects participated in the study. Motor-evoked potentials (MEP) were obtained from conditioning TMS with a varying number of conditioning stimuli in 3, 4, 10, and 15 ms ISI over the primary motor cortex. MEP amplitudes were then compared to examine excitability. TMS with 3, 5, and 7 conditioning stimuli but not with one conditioning stimulus induced ICF. Moreover, 10 ms ISI produced stronger ICF than 15 ms ISI. Significant SICI was only induced with one conditioning stimulus. Besides, 3 ms ISI resulted in stronger SICI than 4 ms ISI. Only a train of conditioning stimuli induced stable ICF and may be more advantageous than the classical paired pulse ICF paradigm. [ABSTRACT FROM AUTHOR]

Objective: The affection of both the peripheral (PNS) and central nervous system (CNS) by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been assumed to play a direct role in the respiratory failure of patients with Corona virus disease 2019 (COVID-19) through affection of medullary cardiorespiratory centers resulting in neurological complications and sequelae. Methods: We used a multimodal electrophysiological approach combined with neuropsychological investigations to study functional alteration of both the PNS and CNS in four patients with severe COVID-19. Results: We found electrophysiological evidence for affection of both the PNS and CNS, and particularly affection of brain stem function. Furthermore, our neuropsychological investigations provide evidence of marked impairment of cognition independent of delirium, and outlasting the duration of acute infection with SARS-CoV-2. Conclusion: This case series provides first direct electrophysiological evidence for functional brain stem involvement in COVID-19 patients without evident morphological changes supporting the notion of the brain stem contributing to respiratory failure and thus promoting severe courses of the disease. Moreover, sustained neuropsychological sequelae in these patients may be of particular psychosocial and possibly also economic relevance for society. [ABSTRACT FROM AUTHOR]

Cortical facilitation assessed with triad conditioning transcranial magnetic stimulation has been termed triad-conditioned facilitation (TCF). TCF has been supposed to reflect increased intracortical facilitation (ICF) at short interstimulus intervals (ISI) around 10 ms and an intrinsic rhythm of the motor cortex at longer ISI around 25 ms. To gain further insight into the pathophysiological mechanism of TCF, we systematically studied the effect of suprathreshold conditioning stimulus (CS) and test stimulus (TS) intensity on TCF. Various CS intensities and TS intensities were used in a triad-conditioning paradigm that was applied to 11 healthy subjects. ISI between pulses were studied between 5 and 200 ms. TCF at 10 ms ISI enhanced with increasing CS intensity but decreased with increasing TS intensity. The duration of facilitation was longer with higher CS intensity. However, TCF at 25 ms ISI could not be elicited with none of the CS and TS intensities addressed here. Our results are consistent with the notion of TCF at short ISI reflecting ICF. The enhanced and prolonged facilitation with increase of CS without additional isolated facilitation at longer ISI suggest a prolongation of ICF. [ABSTRACT FROM AUTHOR]

Background: Recently, therapeutic attempts to control motor choreatic hyperkinesia of Huntington’s disease (HD) by means of pallidal deep brain stimulation (Gp-DBS) were successful. With respect to the clinical effects of Gp-DBS in juvenile hypokinetic-rigid HD (jHD; Westphal variant), only one single-case has been reported up to date. Oscillatory patterns of the Gp in jHD are not known.Objectives and methods: This work aimed to analyse pallidal local field potential oscillations (LFP) in two patients with jHD treated with Gp-DBS. Safety data and clinical scores up to 12 months after DBS-electrode implantation were collected in the framework of a prospective trial (ClinicalTrials.gov; NCT00902889).Results: Intraoperative LFP revealed local alpha and beta oscillations similar to those found in other movement disorders with akinetic rigid and dystonic presentation. Significant motor improvement was not found. There were no treatment-related complications or unresolved long-term adverse events.Conclusions: In spite of similar intraoperative LFP patterns of jHD with those of movement disorders benefitting from DBS, clinical results were not convincing in our patients, so that Gp-DBS in jHD cannot be generally recommended. [ABSTRACT FROM AUTHOR]

Background: Stimulation parameters in deep brain stimulation (DBS) of the subthalamic nucleus for Parkinson's disease (PD) are rarely tested in double-blind conditions. Evidence-based recommendations on optimal stimulator settings are needed. Results from the CUSTOM-DBS study are reported, comparing 2 pulse durations.Methods: A total of 15 patients were programmed using a pulse width of 30 µs (test) or 60 µs (control). Efficacy and side-effect thresholds and unified PD rating scale (UPDRS) III were measured in meds-off (primary outcome). The therapeutic window was the difference between patients' efficacy and side effect thresholds.Results: The therapeutic window was significantly larger at 30 µs than 60 µs (P = ·0009) and the efficacy (UPDRS III score) was noninferior (P = .00008).Interpretation: Subthalamic neurostimulation at 30 µs versus 60 µs pulse width is equally effective on PD motor signs, is more energy efficient, and has less likelihood of stimulation-related side effects. © 2017 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]

Objectives: The triad conditioned facilitation (TCF) technique has been shown to detect motor cortical intrinsic rhythms depending on the functioning of specific cortical layers by measuring motor evoked potential (MEP) enhancement after a triad of conditioning TMS pulses at a certain interval. However, the influence of cortical degeneration on TCF is still undetermined. We therefore studied TCF in patients with amyotrophic lateral sclerosis (ALS), a neurodegenerative disorder characterised by degeneration of the motor cortex. Methods: Thirteen patients with ALS and 11 age-matched disease control patients with cervical myelopathy (CM) or radiculopathy (CR) participated in the study. We studied short-interval intracortical inhibition (SICI), intracortical facilitation (ICF) and TCF using the paired-pulse and triad conditioned TMS paradigm. Results: TCF was significantly reduced in ALS patients compared to CM/CR patients, who had normal TCF. SICI and ICF did not differ between groups. Conclusion: The absence of TCF with preserved SICI and ICF suggests changes in the intrinsic rhythm generation within the motor cortex due to cortical neurodegeneration in ALS patients. In contrast, TCF was normal in patents with CM/CR in whom the motor cortical intrinsic circuits are not involved. This technique may be valuable to differentiate patients with ALS from those with CM/CR. [ABSTRACT FROM AUTHOR]

Somatosensory evoked potentials (SSEPs) are a viable way to measure processing of somatosensory information. SSEPs have been described at the scalp and the cortical level by electroencephalographic, magnetoencephalographic and intracranial cortical recordings focusing on short-latency (SL; latency<40 ms) and long-latency (LL; latency>40 ms) SSEPs as well as by deep brain stimulation (DBS) electrode studies targeting SL-SSEPs. Unfortunately, LL-SSEPs have not been addressed at the subcortical level aside from the fact that studies targeting the characteristics and generators of SSEPs have been neglected for the last ten years. To cope with these issues, we investigated LL-SSEPs of the subthalamic nucleus (STN) in twelve patients with Parkinson’s disease (PD) that underwent deep brain stimulation (DBS) treatment. In a postoperative setting, LL-SSEPs were elicited by median nerve stimulation (MNS) to the patient’s wrists. Ipsilateral or contralateral MNS was applied with a 3 s inter-stimulus interval. Here, we report about four distinctive LL-SSEPs (“LL–complex” consisting of P80, N100, P140 and N200 component), which were recorded by using monopolar/bipolar reference and ipsi/contralateral MNS. Phase reversal and/or maximum amplitude provided support for the generation of such LL-SSEPs within the STN, which also underscores a role of this subcortical structure in sensory processing. [ABSTRACT FROM AUTHOR]

DYT-THAP1 dystonia is known to present a variety of clinical symptoms. To the best of our knowledge, this is the first case with DYT-THAP 1 dystonia and clinical signs of cerebellar involvement studied with transcranial magnetic stimulation in vivo. We report a case of a 51-year-old male DYT-THAP1 mutation carrier with dystonia, who additionally developed ataxia 1.5 years ago. To study cerebellar involvement in our patient, we used a TMS protocol called cerebellar inhibition (CBI). The lack of CBI in our patient strongly suggests cerebellar involvement. According to our findings, cerebellar syndrome may be part of the phenotypical spectrum of DYT-THAP1 mutations. [ABSTRACT FROM AUTHOR]

Huntington's disease (HD) is one of the most disabling degenerative movement disorders, as it not only affects the motor system but also leads to cognitive disabilities and psychiatric symptoms. Deep brain stimulation (DBS) of the pallidum is a promising symptomatic treatment targeting the core motor symptom: chorea. This article gives an overview of preliminary evidence on pathophysiology, safety and efficacy of DBS in HD. [ABSTRACT FROM AUTHOR]

Background: Movement disorders in Huntington's disease are often medically refractive. The aim of the trial was assessment of procedure safety of deep brain stimulation, equality of internal- and external-pallidal stimulation and efficacy followed-up for 6 months in a prospective pilot trial. Methods: In a controlled double-blind phase six patients (four chorea-dominant, two Westphal-variant) with predominant movement disorder were randomly assigned to either the sequence of 6-week internal- or 6-week external-pallidal stimulation, or vice versa, followed by further 3 months chronic pallidal stimulation at the target with best effectside- effect ratio. Primary endpoints were changes in the Unified Huntington's Disease Rating Scale motor-score, chorea subscore, and total motor-score 4 (blinded-video ratings), comparing internal- versus external-pallidal stimulation, and 6 months versus baseline. Secondary endpoints assessed scores on dystonia, hypokinesia, cognition, mood, functionality/disability, and quality-of-life. Results: Intention-to-treat analysis of all patients (n=3 in each treatment sequence): Both targets were equal in terms of efficacy. Chorea subscores decreased significantly over 6 months (-5.3 (60.2%), p=0.037). Effects on dystonia were not significant over the group due to it consisting of three responders (>50% improvement) and three non-responders. Westphal patients did not improve. Cognition was stable. Mood and some functionality/disability and quality-of-life scores improved significantly. Eight adverse events and two additional serious adverse events - mostly internal-pallidal stimulationrelated - resolved without sequalae. No procedure-related complications occurred. Conclusion: Pallidal deep brain stimulation was demonstrated to be a safe treatment option for the reduction of chorea in Huntington's disease. Their effects on chorea and dystonia and on quality-of-life should be examined in larger controlled trials. [ABSTRACT FROM AUTHOR]

Gait disturbance in individuals with spinal cord lesion is attributed to the interruption of descending pathways to the spinal locomotor center, whereas neural circuits below and above the lesion maintain their functional capability. An artificial neural connection (ANC), which bridges supraspinal centers and locomotor networks in the lumbar spinal cord beyond the lesion site, may restore the functional impairment. To achieve an ANC that sends descending voluntary commands to the lumbar locomotor center and bypasses the thoracic spinal cord, upper limb muscle activity was converted to magnetic stimuli delivered noninvasively over the lumbar vertebra. Healthy participants were able to initiate and terminate walking-like behavior and to control the step cycle through an ANC controlled by volitional upper limb muscle activity. The walking-like behavior stopped just after the ANC was disconnected from the participants even when the participant continued to swing arms. Furthermore, additional simultaneous peripheral electrical stimulation to the foot via the ANC enhanced this walking-like behavior. Kinematics of the induced behaviors were identical to those observed in voluntary walking. These results demonstrate that the ANC induces volitionally controlled, walking-like behavior of the legs. This paradigm may be able to compensate for the dysfunction of descending pathways by sending commands to the preserved locomotor center at the lumbar spinal cord and may enable individuals with paraplegia to regain volitionally controlled walking. [ABSTRACT FROM AUTHOR]

Background and Study Aims The use of multiple trajectories microelectrode recording (MER) during implantation of deep brain stimulation (DBS) electrodes into the subthalamic nucleus (STN) in patients with Parkinson's disease (PD) is discussed controversially because of possible risks and unclear benefits. The aim of the study is to investigate whether MER combined with intraoperative evaluation of stimulation effects improve clinical outcome in PD patients undergoing STN DBS surgery. Material and Methods Prior to final DBS electrode implantation, we performed multiple trajectories MER and intraoperative test stimulations aftermagnetic resonance imaging (MRI)-guided planning in 32 PD patients. In further 10 patients no MER (only intraoperative test stimulation) was used. Results We found a significantly better clinical outcome (Unified Parkinson's Disease Rating Scale [UPDRS] III) in patients undergoing MER compared with non-MER patients. In MER patients, DBS electrode placement was performed using the central trajectory in 73%. Another than the central trajectory was taken in 27% of the patients. No difference in clinical outcome between DBS electrodes implanted on the central or a decentral trajectory was observed. Conclusions DBS surgery based on intraoperative multiple trajectories MER and test stimulation improves clinical outcome if compared with intraoperative test stimulation alone. The data suggest that DBS surgery solely based on MRI and intraoperative test stimulation without MER may lead to nonoptimal placement of DBS electrodes and consequently poorer clinical outcome. [ABSTRACT FROM AUTHOR]

Background/Objective: Corticobasal syndrome (CBS) is a rare neurodegenerative disorder characterized by a progressive and asymmetric manifestation of cortical and basal-ganglia symptoms of different origin. The spatio-temporal dynamics of cerebral atrophy in CBS is barely known. This study aimed to longitudinally quantify the individual dynamics of brain volume changes in patients with CBS as compared to healthy controls. Methods: We used deformation-field-based morphometry (DFM) to study volumetric changes of each individual brain in short intervals of a few months. DFM enabled the quantitative analysis of local volume changes without predefining regions of interest in MR images of 6 patients with CBS and 11 matched healthy controls. A total of 64 whole brain 3D-MR-scans were acquired two to eight times over periods of 14 to 26 months. Based on repeated registrations of MR observations to the initial scan, maps of local volume ratio changes were computed. Results: Compared to controls patients showed significant and increasing volume loss over time in premotor and primarymotor- cortices, somatosensory area 3a, superior parietal areas BA 5/7, and corticospinal tract. Furthermore, significant and asymmetric atrophy was identified in the caudate nucleus head, putamen, pallidum, motor-thalamus and substantia nigra. Temporal lobe was affected in those patients who presented progressive cognitive impairment. Conclusions: The analysis revealed localized, pathological changes in brains of patients with CBS, which differed significantly from those occurring during aging in healthy controls. As compared to age- and sex-matched controls, brains of CBS patients showed a common degenerating neural network comprising the motor circuit with basal ganglia and motor thalamic nuclei as well as the premotor and primary-motor-cortex. [ABSTRACT FROM AUTHOR]

The mechanism and time course of emotional side effects of subthalamic deep brain stimulation in Parkinson's disease are a matter for discussion. We report a 53-month follow-up of a patient with affective lability. Postoperative lesion plus bilateral stimulation strongly influenced mood in the first week in terms of laughing behavior, while voltage changes had only minor long-term impact up to 37 months on negative emotion, possibly caused by the right electrode stimulating the subthalamic nucleus and adjacent fiber tracts involving the internal capsule. Thus we conclude that affective lability can occur with different temporal dynamics of microlesion, and early and chronic stimulation. [ABSTRACT FROM AUTHOR]

To evaluate on-line effects of quadripulse stimulation (QPS) over the primary motor cortex (M1) on cortical areas in the contralateral hemisphere. QPS consisted of 24 bursts of transcranial magnetic stimulation (TMS) pulses with an inter-burst interval of 5 s for 2 min (for on-line effect study) or 360 bursts for 30 min (for after-effect study). Each burst consisted of four TMS pulses (i.e. QPS) separated by an interstimulus interval of 5 or 50 ms (QPS-5 or QPS-50). QPSs were delivered over the left M1. Experiment 1 [on-line effect on somatosensory evoked potential (SEP)]: Left median nerve SEPs were recorded before, during and after QPS. Experiment 2 (after effect on SEP): After-effects of QPS were evaluated by following up SEPs after the QPS sessions. Experiment 3 (on-line effect on NIRS): Near infrared spectroscopy (NIRS) was also recorded at the right hemisphere during all QPS paradigms. Both QPS-5 and QPS-50 enlarged a cortical component of the contralateral SEP during stimulation. On the other hand, concerning the after effects, QPS-5 over M1 potentiated the contralateral SEP and QPS-50 tended to depress it. In NIRS study, both QPS-5 and QPS-50 induced a significant oxy-Hb decrease (deactivation pattern) at the right hemisphere during stimulation whereas sham stimulations unaffected them. We have shown the unidirectional on-line effects evoked by QPS-5 and QPS-50 on both SEP and NIRS, and bidirectional after effects on SEP at the contralateral hemisphere. The discrepancy between on-line effect and after effect may be explained by the differences in the underlying mechanisms between them. The former may be mainly explained by pure electrophysiological property changes in the membrane or synapses. The latter may be explained by synaptic efficacy changes which need some protein syntheses at least partly. Another discrepancy shown here is the direction of on-line effects. Electrophysiological (SEP) function was potentiated by both QPSs whereas hemodynamic (NIRS) function was depressed. This may be explained by which sensory areas contribute to NIRS or SEP generation. [ABSTRACT FROM AUTHOR]

Timing in the range of seconds referred to as interval timing is crucial for cognitive operations and conscious time processing. According to recent models of interval timing basal ganglia (BG) oscillatory loops are involved in time interval recognition. Parkinsons disease (PD) is a typical disease of the basal ganglia that shows distortions in interval timing. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a powerful treatment of PD which modulates motor and cognitive functions depending on stimulation frequency by affecting subcortical-cortical oscillatory loops. Thus, for the understanding of BG-involvement in interval timing it is of interest whether STN-DBS can modulate timing in a frequency dependent manner by interference with oscillatory time recognition processes. We examined production and reproduction of 5 and 15 second intervals and millisecond timing in a double blind, randomised, within-subject repeated-measures design of 12 PD-patients applying no, 10-Hz- and ≤130-Hz-STN-DBS compared to healthy controls. We found under(re- )production of the 15-second interval and a significant enhancement of this under(re-)production by 10-Hz-stimulation compared to no stimulation, ≤130-Hz-STN-DBS and controls. Milliseconds timing was not affected. We provide first evidence for a frequency-specific modulatory effect of STN-DBS on interval timing. Our results corroborate the involvement of BG in general and of the STN in particular in the cognitive representation of time intervals in the range of multiple seconds. [ABSTRACT FROM AUTHOR]

A case of isolated unilateral hypertrophy of the Musculus temporalis identified by magnetic resonance imaging associated with recurrent hemicranial headache in a 22-year-old woman with Turkish ancestry is presented. Symptomatic relief was achieved by administration of acetaminophen. A review of the literature is presented and additional treatment options are discussed. [ABSTRACT FROM AUTHOR]

We simultaneously recorded local field potentials (LFPs) in the subthalamic nucleus (STN) and surface electromyographic signals (EMGs) from the extensor and flexor muscles of the contralateral forearm in eight patients with idiopathic tremor-dominant Parkinson’s disease (resting tremor) during the bilateral implantation of deep brain stimulation electrodes. Recordings were made at different heights (in 0.5- to 2.0-mm steps beginning outside the STN) using up to five concentrically configured macroelectrodes (2 mm apart). The patients were instructed to relax their contralateral forearm (rest condition). We analysed the coherence between tremor EMGs and STN LFPs, which showed significant tremor-associated coupling at single tremor and double tremor frequencies. Moreover, the EMG–LFP coherences were characterised by differences between antagonistic muscles (flexor, extensor) and by the spatial distribution of LFPs within the STN. Coherence at single and double tremor frequencies occurred significantly more frequently within STN than above STN (in the zona incerta). In this study, we were able to show that, within STN, tremor-associated LFP activity varied with spatial distribution and with the contralateral antagonistic forearm muscles. These findings suggest the existence of distribution- and muscle-specific tremor-associated LFP activity at different tremor frequencies and an organisation of tremor-related subloops within the STN. [ABSTRACT FROM AUTHOR]

Cardinal symptoms of Parkinson's disease (PD) respond well to treatment with levodopa and deep brain stimulation (DBS) of the subthalamic nucleus (STN). However, it has remained unclear whether levodopa and STN-DBS have differential effects on bradykinesia. We investigated 8 PD-patients with STN-electrodes in four conditions: STN-DBS and levodopa (ONMED/ONSTIM), STN-DBS only (OFFMED/ONSTIM), levodopa only (ONMED/OFFSTIM), without STN-DBS/levodopa (OFFMED/OFFSTIM). Fourteen volunteers served as controls. Subjects performed fastest possible (1) pronation/supination of the forearm (diadochokinesia) and (2) flexion and extension of the index finger (finger movements). Movements were recorded using a 3D-ultrasound-system. Maximum frequency, amplitude, and smoothness of movements were determined. During OFFMED/OFFSTIM, all parameters were worser than in all other conditions. In proximal diadochokinesia, OFFMED/ONSTIM significantly improved the amplitude and frequency, whereas ONMED/OFFSTIM had no significant effect. In contrast, we found a stronger effect of levodopa (ONMED/OFFSTIM) on amplitudes of distal finger movement than on amplitudes of diadochokinesia. Combination of treatments during ONMED/ONSTIM further improved both movements. However, maximum frequency remained lower in PD-patients during ONMED/ONSTIM compared with controls. This study demonstrates a better effect of levodopa on distal finger movements and STN-DBS on proximal diadochokinesia. Furthermore, a complementary effect of both therapies on brain areas involved in bradykinesia can be assumed. © 2007 Movement Disorder Society [ABSTRACT FROM AUTHOR]

In this paper, an optoelectronic receiver IC for CD, DVD, and Blue. Laser optical data storage applications is presented. The lC was developed in a 0.5-µm BiCMOS technology with integrated PIN photodiodes. It includes a new architecture of high-speed and low-noise variable gain transimpedance amplifiers witch current preamplifier input. The amplifier transimpedance gain is programmable over a gain range of 130 Δ to 270 kΔ by a serial interface. The amplifier small-signal bandwidth is 260 MHz for the highest gain, which gives a gain-bandwidth product of 70 THzΔ and a sensitivity improvement by a factor of 2 compared to published OEICs. The amplifiers support a special write/clip mode which realizes a nonlinear gain reduction for high input signals. The output voltage buffers are 130-Δ impedance matched for optimized data transmission over a ilex cable. The impedance is generated by active-impedance synthesis to increase the output dynamic range. [ABSTRACT FROM AUTHOR]

Presents a three dimensional finite element analysis to calculate the resonance frequencies and quality factors of inhomogeneously loaded cavity resonators terminated by n waveguides. Problem formulation; Selection of perfectly matched layer (PML) parameters; Scattering matrix reconstruction; Numerical examples; Conclusions.

The cerebellum plays an important role in movement execution and motor control by modulation of the primary motor cortex (M1) through cerebello-thalamo-cortical connections. Transcranial magnetic stimulation (TMS) allows direct investigations of neural networks by stimulating neural structures in humans noninvasively. The motor evoked potential to single-pulse TMS of M1 is used to measure the motor cortical excitability. A conditioning stimulus over the cerebellum preceding a test stimulus of the contralateral M1 enables us to study the cerebellar regulatory functions on M1. In this brief review, we describe this cerebellar stimulation method and its usefulness as a diagnostic tool in clinical neurophysiology. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented regarding the new missense mutation of ε-sarcoglycan (SGCE) gene in a patient with myoclonus-dystonia syndrome (MDS) .

Background: To identify mechanisms of cortical plasticity of the visual cortex and to quantify their significance, sensitive parameters are warranted. In this context, multifocal visual evoked potentials (mfVEPs) can make a valuable contribution as they are not associated with cancellation artifacts and include also the peripheral visual field.Objective: To investigate if occipital repetitive transcranial magnetic stimulation (rTMS) can induce mfVEP changes.Methods: 18 healthy participants were included in a single-blind crossover-study receiving sessions of excitatory, occipital 10 Hz rTMS and sham stimulation. MfVEP was performed before and after each rTMS session and changes in amplitude and latency between both sessions were compared using generalized estimation equation models.Results: There was no significant difference in amplitude or latency between verum and sham group.Conclusion: We conclude that occipital 10 Hz rTMS has no effect on mfVEP measures, which is in line with previous studies using full field VEP. [ABSTRACT FROM AUTHOR]

During the last 30 years, deep brain stimulation (DBS) has evolved into the clinical standard of care as a highly effective treatment for advanced Parkinson's disease. Careful patient selection, an individualized anatomical target localization and meticulous evaluation of stimulation parameters for chronic DBS are crucial requirements to achieve optimal results. Current hardware-related advances allow for a more focused, individualized stimulation and hence may help to achieve optimal clinical results. However, current advances also increase the degrees of freedom for DBS programming and therefore challenge the skills of healthcare providers. This review gives an overview of the clinical effects of DBS, the criteria for patient, target, and device selection, and finally, offers strategies for a structured programming approach. [ABSTRACT FROM AUTHOR]