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Orthostatic tremor is a rare movement disorder characterized by a sensation of unsteadiness and leg tremor while standing. It has been hypothesized that the disorder is attributable to dysregulation of a central oscillatory network in the brain. This putative network includes primary motor cortex, supplementary motor area, cerebellum, thalamus, and pontine tegmentum. We studied this brain network by recording resting-state functional MRI data from individuals with orthostatic tremor. For each participant, we measured resting-state functional connectivity using a seed-based approach. Regions of interest included were components of the putative central oscillatory network and a primary motor thumb region (identified via transcranial magnetic stimulation). A non-central oscillatory network region of interest-posterior cingulate cortex-was included for comparative analysis of a well-characterized intrinsic network, the default mode network. Demographic information, medical history, and tremor characteristics were collected to test associations with functional connectivity. For normative context, data from the 1000 Functional Connectomes Project were analyzed using an identical approach. We observed that tremor and demographic variables were correlated with functional connectivity of central oscillatory network components. Furthermore, relative to healthy comparison participants, patients with orthostatic tremor exhibited qualitatively different patterns of cerebellar resting state functional connectivity. Our study enhances the current understanding of brain network differences related to orthostatic tremor and is consistent with a hypothesized selective decoupling of cerebellum. Additionally, associations observed between functional connectivity and factors including medical history and tremor features may suggest targets for treatment of orthostatic tremor.

The aim of this consensus paper is to discuss the roles of the cerebellum in human gait, as well as its assessment and therapy. Cerebellar vermis is critical for postural control. The cerebellum ensures the mapping of sensory information into temporally relevant motor commands. Mental imagery of gait involves intrinsically connected fronto-parietal networks comprising the cerebellum. Muscular activities in cerebellar patients show impaired timing of discharges, affecting the patterning of the synergies subserving locomotion. Ataxia of stance/gait is amongst the first cerebellar deficits in cerebellar disorders such as degenerative ataxias and is a disabling symptom with a high risk of falls. Prolonged discharges and increased muscle coactivation may be related to compensatory mechanisms and enhanced body sway, respectively. Essential tremor is frequently associated with mild gait ataxia. There is growing evidence for an important role of the cerebellar cortex in the pathogenesis of essential tremor. In multiple sclerosis, balance and gait are affected due to cerebellar and spinal cord involvement, as a result of disseminated demyelination and neurodegeneration impairing proprioception. In orthostatic tremor, patients often show mild-to-moderate limb and gait ataxia. The tremor generator is likely located in the posterior fossa. Tandem gait is impaired in the early stages of cerebellar disorders and may be particularly useful in the evaluation of pre-ataxic stages of progressive ataxias. Impaired inter-joint coordination and enhanced variability of gait temporal and kinetic parameters can be grasped by wearable devices such as accelerometers. Kinect is a promising low cost technology to obtain reliable measurements and remote assessments of gait. Deep learning methods are being developed in order to help clinicians in the diagnosis and decision-making process. Locomotor adaptation is impaired in cerebellar patients. Coordinative training aims to improve the coordinative strategy and foot placements across strides, cerebellar patients benefiting from intense rehabilitation therapies. Robotic training is a promising approach to complement conventional rehabilitation and neuromodulation of the cerebellum. Wearable dynamic orthoses represent a potential aid to assist gait. The panel of experts agree that the understanding of the cerebellar contribution to gait control will lead to a better management of cerebellar ataxias in general and will likely contribute to use gait parameters as robust biomarkers of future clinical trials., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: Orthostatic tremor (OT) is a rare neurological disorder characterized by a sensation of instability while standing. Very few clinical signs have been described for OT to date. Finding other symptoms and signs could prove valuable for this hard-to-recognized disease., Methods: This protocol is part of the University of Nebraska Medical Center Orthostatic Tremor longitudinal study. It was noted that OT patients flex their toes and sometimes the foot arch while standing (Plantar Grasp). They reported doing this to "grab" the floor and improve stability. This paper analyses the diagnostic test characteristics of the patient-self-reported Plantar Grasp, a new sign in OT., Results: There were 34 OT patients (88% females), and 20 controls (65% females). Eighty-eight percent of patients with OT reported the plantar grasp sign and none of the controls. The Plantar Grasp Sign was found to be very sensitive (88%), and extremely specific (100%) in our cohort. Non-weighted Negative Likelihood Ratio (NLR) was 0.12. And the 3% prevalence-weighted NLR was so low that the negative post-test probability was close to zero., Conclusion: Due to its high sensitivity, specificity, and ideal likelihood ratio, we propose that the Plantar Grasp sign could be considered to screen patients with possible OT. Further studies are needed to determine the specificity of this sign in OT versus other balance disorders., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Background: Orthostatic tremor (OT) is characterized by a sensation of instability while standing, associated with high frequency (1318 Hz) tremor in the legs. Small retrospective series have reported electroencephalography (EEG) findings in OT with discordant results., Methods: We prospectively enrolled 30 OT subjects. Mean age = 68.3 (range 5487) with mean disease duration 16.3 years (range 444). A modified 1020 system EEG recording with additional midline electrodes was obtained. EMG electrodes were placed on quadricep muscles. EEG recording was performed at rest, during sleep and while standing unassisted., Results: In all subjects, EEG showed normal background, normal drowsiness and/or stage 2 sleep, and normal responses to hyperventilation and photic stimulation. These normal results persisted during stance. EEG abnormalities were found in 3 subjects (anterior-mid temporal slow activity), but were not position-dependent and were judged unlikely to be related to OT. Tremor artifact while standing was noted in all subjects, however it was measurable in 26 with frequency in the OT range in 25. When compared with EMG, the average difference in frequency was small at 1.2 Hz (range 0.52.5, p 0.46). Visual EEG analysis in OT patients did not reveal electrographic abnormalities even upon standing unassisted., Discussion: EEG was normal on this prospective, relatively large OT series. Clinicians interpreting video-EEGs should be aware of the OT artifact that can be seen in EEG and EKG leads mostly while standing., Competing Interests: The authors have no competing interests to declare., (Copyright: 2021 The Author(s).)

Background: The exact pathophysiology of primary Orthostatic Tremor (OT) is unknown. A central oscillator is assumed, and previous imaging studies show involvement of cerebellar pathways. However, the presence of ataxia on clinical exam is disputed. We set out to study ataxia in OT prospectively., Methods: EMG-confirmed primary OT subjects and spousal controls received a neurological exam with additional semiquantitative evaluations of ataxia as part of a multinational, prospective study. These included detailed limb coordination (DLC), detailed stance and gait evaluation (DS), and the Brief Ataxia Rating Scale (BARS). Intra- and inter-rater reliability were assessed and satisfactory., Results: 34 OT subjects (mean age = 67 years, 88% female) and 21 controls (mean age = 66 years, 65% male) were enrolled. Average disease duration was 18 years (range 4-44). BARS items were abnormal in 88% of OT patients. The OT subjects were more likely to have appendicular and truncal ataxia with significant differences in DLC, DS and BARS. Ocular ataxia and dysarthria were not statistically different between the groups., Discussion: Mild-to-moderate ataxia could be more common in OT than previously thought. This is supportive of cerebellar involvement in the pathophysiology of OT. We discuss possible implications for clinical care and future research., Highlights: Previous studies of Primary Orthostatic Tremor (OT) have proposed pathophysiologic involvement of the cerebellar pathways.However, presence of ataxia has not been systematically studied in OT.This is a prospective comprehensive ataxia assessment in OT compared to controls. Mild-to-moderate appendiculo-truncal ataxia was found to be common in OT., Competing Interests: The authors have no competing interests to declare., (Copyright: © 2020 The Author(s).)

Introduction: Although stigma has been linked to poor quality of life, studies examining its prevalence in dystonia are lacking. Our objective was to determine prevalence and predictors of stigma against generalized dystonia in diverse cultural settings., Method: Participants were 273 (65.9% female) patients and visitors approached at primary care clinics from three populations: León, Nicaragua (92 participants); a mostly-Hispanic Clinic in Omaha, NE USA (85 participants); and a mostly-non-Hispanic population in Omaha, Nebraska (96 participants). Participants learned about generalized dystonia, epilepsy and schizophrenia through reading a small vignette and viewing videos, followed by a questionnaire designed to identify stigma. We compared levels of stigma between dystonia and other conditions at different sites and measured variables that could affect them., Results: Prevalence of stigma was high toward dystonia (33.00%), similar to epilepsy and lower than schizophrenia. The results showed a complex relationship between the studied variables and level of stigma, especially with age. Female gender predicted more stigmatizing answers. Country of origin, level of education and self-identification of Hispanic ethnicity did not affect stigma. Learning more personal information about the dystonia patient decreased dystonia, a proof that unjustified preliminary negative judgment was present., Conclusions: Stigma against generalized dystonia was very prevalent across all the communities studied. Demographic and socio-cultural variables had different correlations to level of stigma, underlying the complexity of this problem. The alarming levels of stigma against dystonia justify further studies on how to minimize its impact on our patients., (© 2020 The Authors.)

Orthostatic tremor (OT) is a rare movement disorder characterized by a fast tremor (13-18 Hz) in the lower extremities during stance. Patients with OT typically complain of instability while standing/walking. However, due to the geographical limitation, the standing instability or gait problems in patients with OT cannot be assessed and monitored frequently. The increasing popularity of using smartphone-based accelerometers could be a solution to eliminate this limitation. This study examined the feasibility of using smartphone-based accelerometers to identify the changes in body movement in different standing and locomotor tasks. Twenty patients with OT and seven healthy controls were consented to participate in this study. Subjects stood with eyes open or eyes closed for 20 seconds. They also performed four different locomotor tasks (normal walking, tandem walk, walking on an elevated surface, and obstacle negotiation). When performed different locomotor tasks, patients with OT had a larger acceleration of body movement than controls in the medial-lateral direction (tandem walk: p = 0.026, walking on an elevated surface: p = 0.002, and stepping over the obstacle: p = 0.028). Patients with OT had smaller acceleration of body movement than controls while standing with eyes open in the vertical direction (p = 0.012), in the anterior-posterior direction (p = 0.013) and in the medial-lateral direction (p = 0.011). This study provides objective evidence of balance instability in patients with OT not only while standing but also during different challenging locomotor tasks by using smartphone-based accelerometers., Competing Interests: All authors have read and approved the manuscript, it has not been submitted nor published elsewhere in whole or in part, except as an abstract. For competing interests, JHC has no disclosures; DT-R is a consultant/speaker for Allergan, Teva, AbbVie, Ipsen, and Lundbeck; ZW, CG, DW, and K-CS report no disclosures. Importantly, these statements do not alter our adherence to PLOS ONE policies on sharing data and materials.

Objective: To report a 2017 survey of all US medical school neurology clerkship directors (CDs) and to compare the results to similar surveys conducted in 2005 and 2012., Methods: An American Academy of Neurology (AAN) Consortium of Neurology Clerkship Directors (CNCD) workgroup developed the survey that was sent to all neurology CDs listed in the AAN CNCD database. Comparisons were made to similar 2005 and 2012 surveys., Results: The response rate was 92 of 146 programs (63%). Among the responding institutions, neurology is required in 94% of schools and is 4 weeks in length in 75%. From 2005 to 2017, clerkships shifted out of a fourth-year-only rotation ( p = 0.035) to earlier curricular time points. CD protected time averages 0.24 full-time equivalent (FTE), with 31% of CDs reporting 0.26 to 0.50 FTE support, a >4-fold increase from prior surveys ( p < 0.001). CD service of >12 years increased from 9% in 2005 to 23% in 2017. Twenty-seven percent also serve as division chief/director, and 22% direct a preclinical neuroscience course. Forty-nine percent of CDs are very satisfied in their role, increased from 34% in 2012 ( p = 0.046). The majority of CDs identify as white and male, with none identifying as black/African American., Conclusion: Changes since 2005 and 2012 include shifting of the neurology clerkship to earlier in the medical school curriculum and an increase in CD salary support. CDs are more satisfied than reflected in previous surveys and stay in the role longer. There is a lack of racial diversity among neurology CDs., (© 2018 American Academy of Neurology.)

Introduction: Evaluation of people with Parkinson's disease (PD) is often complex due to heterogeneity of symptoms and disease course, including the variability of motor fluctuations and dyskinesia. Routine clinical evaluations may be incomplete, may not accurately capture important symptoms, and may not reflect day-to-day variability. While significant advances have been made in wearable ambulatory continuous objective monitoring (COM) technologies, many clinicians remain uncertain of how to incorporate them in clinical practice, including the value to clinical decision-making. The Personal KinetiGraph™ (PKG) has FDA clearance in the United States, and has recently been used in several clinical studies. Areas covered: An expert group of movement disorders neurologists convened to discuss the clinical utility of the PKG in the routine assessment of people with PD. Based on their experience, the group identified clinical scenarios where objective information gained from review of PKG reports can provide useful information to improve clinical management. Expert commentary: PKG provides clinically meaningful data in patients with PD that can aid the clinician in evaluating patients and optimizing their pharmacologic therapy. Early clinical experience and expert opinion suggest that utilization of COM technologies such as the PKG have the potential to improve medical care in people with PD.

Purpose of Review: Orthostatic tremor (OT) is a rare disorder characterized by tremor and a feeling of unsteadiness while standing that resolve upon walking or sitting. A pathognomonic 13-18 Hz tremor is seen on surface EMG while standing. Though its clinical features have been better defined over time, much of its pathophysiology remains unknown and treatment options are limited. We review here recent developments in both of these areas., Recent Findings: Several recent studies have furthered our understanding of the central oscillatory network involved in OT. fMRI and 18 F-FDG-PET studies have identified a ponto-cerebello-thalamo-cortical network underlying OT, though the nature of its dysfunction remains unknown. Randomized trials of treatments for OT are few, so most data are from case reports or small case series. Clonazepam and gabapentin are likely the most effective medical therapies, while bilateral ventral intermediate nucleus deep brain stimulation shows promise for refractory cases. Though much about OT remains unknown, our understanding of its pathophysiology has improved through recent studies. Treatment benefit is overall modest and inconsistent, though better understanding of the disease could lead to new avenues for treatment.

Non-ketotic hyperglycaemia (NKH) is the most common metabolic cause of hemichorea-hemiballismus (HC-HB) and an often-reversible condition. A 68-year-old man presented to the emergency department with a severe hyperglycaemic episode and altered mental status. He was treated appropriately and discharged home after his blood glucose levels were normal with an improvement of mental status. Four weeks after the discharge, he returned with flailing movements of bilateral upper and lower limbs. MRI of the brain revealed hyperintensities of the bilateral putamen on T1-weighted imaging. The patient ' s symptoms improved with a combination of amantadine, clonazepam and tetrabenazine. Several hypotheses involving gemistocytes, calcification and petechial haemorrhage were proposed in support of imaging abnormalities in the striatum. Dopamine-depleting agents and neuroleptics are used in the treatment of chorea. It is recommended to try a dose of tetrabenazine in patients with NKH-induced HC-HB if no improvement is appreciated with initial treatment of glycaemic control., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Introduction: Orthostatic Tremor (OT) is a movement disorder characterized by a sensation of unsteadiness and tremors in the 13-18 Hz range present upon standing. The pathophysiology of OT is not well understood but there is a relationship between the sensation of instability and leg tremors. Despite the sensation of unsteadiness, OT patients do not fall often and balance in OT has not been formally assessed. We present a prospective blinded study comparing balance assessment in patients with OT versus healthy controls., Methods: We prospectively enrolled 34 surface Electromyography (EMG)-confirmed primary OT subjects and 21 healthy controls. Participants underwent evaluations of balance by blinded physical therapists (PT) with standardized, validated, commonly used balance scales and tasks., Results: OT subjects were mostly female (30/34, 88%) and controls were majority males (13/20, 65%). The average age of OT subjects was 68.5 years (range 54-87) and for controls was 69.4 (range 32-86). The average duration of OT symptoms was 18 years. OT subjects did significantly worse on all the balance scales and on most balance tasks including Berg Balance Scale, Functional Gait Assessment, Dynamic Gait Index, Unipedal Stance Test, Functional Reach Test and pull test. Gait speed and five times sit to stand were normal in OT., Conclusions: Common validated balance scales are significantly abnormal in primary OT. Despite the objective finding of impaired balance, OT patients do not commonly have falls. The reported sensation of unsteadiness in this patient population seems to be out of proportion to the number of actual falls. Further studies are needed to determine which components of commonly used balance scales are affected by a sensation of unsteadiness and fear of falling., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Neuropsychiatric sequelae have been reported in 15%-45% of survivors of carbon monoxide (CO) poisoning. Hyperbaric oxygen (HBO₂) therapy reduces the incidence of cognitive and neurological a dysfunction. The efficacy of providing HBO₂ beyond the first one to two days after initial insult is unknown. However, some evidence exists for the benefit of this treatment. We report on treating a patient 14 months after CO injury, who responded with markedly improved neurologic status. A 27-year-old scholar was found comatose due to CO poisoning (carboxyhemoglobin = 31.7%). He received five acute HBO₂ treatments. After discharge, he developed chorea, Parkinsonism, dystonia, memory loss, slowed processing speed and verbal fluency, leaving him disabled. After the patient reached a clinical plateau, HBO₂ was tried again at 90 minutes at 2.4 ATA plus air breaks. Neuropsychological testing was performed at baseline and after each 20 HBO₂ cycles, five of which were performed during the period from 14-22 months after CO exposure. After the first 20 treatments, Parkinsonism and dystonia improved. After 40 sessions, further improvements were seen on mental speed, verbal fluency, and fine motor movements. The outcome following 100 treatments was that the patient regained independence, including the ability to drive and to become gainfully employed. Our case calls into question the concept that HBO₂ therapy has no role during the chronic phase of CO brain injury. Randomized clinical trials should be considered to evaluate the therapeutic efficacy of HBO₂ in patients with neurological sequelae following CO injury., Competing Interests: The authors of this paper declare no conflicts of interest exist with this submission., (Copyright© Undersea and Hyperbaric Medical Society.)

Background: Tremor is a known side-effect of anticonvulsants, particularly of valproate. However, there is a dearth of information regarding detailed clinical features and functional impact of valproate-induced tremor., Methods: We studied a cohort of patients treated with anticonvulsants for neurological disorders, through blinded evaluations using the Clinical Rating Scale for Tremor (CRST); we compared the frequency, severity and functional impact of drug-induced tremor between patients treated with valproate and those treated with other anticonvulsants., Results: From a cohort of 218 consecutive patients, 171 were fully evaluated; 118 patients were taking valproate alone or combined with other anticonvulsants and 53 patients were taking other anticonvulsants. Mean age (±SD) at evaluation of the cohort was 32 ± 13 years, females represented 55.6% of cases. Tremor was more frequently observed in patients taking valproate particularly postural upper limb tremor: 49% vs. 15% (right-side) (P < 0.001) and 48.3% vs. 13.2% (left-side), (P < 0.001); had a higher total CRST score: 12.14 vs. 3.06 (P < 0.001), and required more frequently treatment for drug-induced tremor: 23.7% vs. 5.6% (P=0.005) compared with patients taking other anticonvulsants. Among 118 patients taking valproate, women had a higher total CRST score compared with men: 14.54 ± 14.9 vs. 9.56 ± 9.55 (P=0.034). A weak correlation between the total CRST score, dose per Kg of valproate and serum levels of valproate were observed., Conclusions: Tremor is frequently observed in patients taking valproate and is severe enough to require treatment in about 24% of cases., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: Orthostatic Tremor (OT) is characterized by the presence of a sensation of instability while standing, associated with high frequency (13-18 Hz) lower extremity tremor. Diagnosis is confirmed with surface electromyography (EMG). An accurate screening tool that could be used in the routine clinical setting, without any specialized equipment, would be useful in earlier detection of OT and judicial use of additional testing., Objective: The objective of this study was to evaluate OT diagnostic test characteristics at bedside using iPhone's built-in accelerometer and available applications for tremor recordings., Methods: We obtained recordings using iPhones (Model 5, 5s, and 6) and free Applications ("LiftPulse" by LiftLabs [App1] and "iSeismometer" by ObjectGraph LLC [App2]) at default settings., Results: 24 EMG-confirmed OT subjects (mostly females, 22/24) and 15 age-matched controls (mostly males, 11/15) were evaluated. App1 detected OT range tremor in 22/24 patients and none of the controls. (Sensitivity = 92%, Specificity = 100%, NPV = 88%). App2 detected OT range tremor in 21/24 patients and in 1/13 controls (Sensitivity = 88%, Specificity = 92%, NPV = 80%). When combined, 24/24 patients and 1/13 controls had OT range tremor (Sensitivity = 100%, Specificity = 92%, NPV = 100%)., Conclusions: Smartphone apps that use the built-in accelerometer provide a simple, accurate and inexpensive bedside screening diagnostic tool for patients with OT.

Objective: The aim of this study was to examine the efficacy, safety and dosing practices of rimabotulinumtoxinB (BoNT-B) for the treatment of patients with sialorrhea based on a systematic review of clinical trials., Methods: A systematic literature review was performed to identify randomized controlled trials and other comparative clinical studies of BoNT-B for the treatment of sialorrhea published in English between January 1999 and December 2015. Medical literature databases (PubMed, Cochrane Library, and EMBASE) were searched and a total of 41 records were identified. Of these, six primary publications that evaluated BoNT-B for the treatment of sialorrhea met criteria and were included in the final data report., Synthesis: Total BoNT-B doses ranged from 1500 to 4000 units for sialorrhea. Most of the studies in sialorrhea showed statistically significant benefits of BoNT-B versus placebo (range 4-19.2 weeks). BoNT-B was generally well tolerated across the individual studies; most adverse events reported were considered unrelated to treatment. Adverse events considered potentially associated with BoNT-B included: dry mouth, change in saliva thickness, mild transient dysphagia, mild weakness of chewing and diarrhea., Conclusions: BoNT-B significantly reduces sialorrhea at doses between 1500 and 4000 units. The relatively mild dose-dependent adverse events suggest both direct and remote toxin effects.

Blepharospasm is a focal (although usually bilateral) dystonia of the orbicularis oculi muscles, producing excessive eye closure. This produces significant disability through functional blindness. Botulinum neurotoxins (BoNT) have become the treatment of choice for blepharospasm; the impressive response rate and the tolerable safety profile have been proven through multiple clinical studies. There are currently four BoNT approved in the United States for different indications - we review the data on blepharospasm for each of these drugs. Currently, incobotulinumtoxinA and onabotulinumtoxinA have the most evidence of benefit for patients with blepharospasm. Current evidence, recent development and future directions are discussed.

Parkinson's disease (PD) is a neurodegenerative disorder associated with debilitating motor, posture, and gait abnormalities. Human studies recording local field potentials within the subthalamic nucleus and scalp-based electroencephalography have shown pathological beta synchronization throughout the cortical-basal ganglia motor network in PD. Suppression of such pathological beta synchronization has been associated with improved motor function, which may explain the effectiveness of deep-brain stimulation. We used magnetoencephalography (MEG) to investigate neural population-level beta responses, and other oscillatory activity, during a motor task in unmedicated patients with PD and a matched group of healthy adults. MEG is a noninvasive neurophysiological technique that permits the recording of oscillatory activity during movement planning, execution, and termination phases. Each of these phases was independently examined using beamforming to distinguish the brain areas and movement phases, where pathological oscillations exist during motor control. Patients with PD exhibited significantly diminished beta desynchronization compared with controls prior to and during movement, which paralleled reduced alpha desynchronization. This study is the first to systematically investigate neural oscillatory responses in PD during distinct stages of motor control (e.g. planning, execution, and termination) and indicates that these patients have significant difficulty suppressing cortical beta synchronization during movement planning, which may contribute to their diminished movement capacities., (© The Author 2013. Published by Oxford University Press.)

A 63-year-old male radio announcer was admitted with a narrow complex, long RP tachycardia. While in the awake state, the patient spoke in his radio voice, initiating and maintaining the tachycardia. Three-dimensional electroanatomic mapping during electrophysiology study localized the tachycardia to the ostium of the right superior pulmonary vein. After single radiofrequency energy application, no further arrhythmias were inducible with speech. At more than 1 year of follow-up, the patient had no recurrences and continues to work as a radio announcer., (© 2013 Wiley Periodicals, Inc.)

Deep brain stimulation (DBS) is an accepted therapy for people with Parkinson's disease (PD) motor symptoms that are refractory to pharmacologic therapy. Standard DBS targets are globus pallidus interna (GPi) and subthalamic nucleus (STN). The pedunculopontine nucleus (PPN) is being investigated as a novel target. Which target provides the best outcomes is unknown. The utility of GPi and STN as targets has been confirmed in numerous studies, including randomized comparisons of GPi DBS and STN DBS that demonstrated no difference in motor outcomes. DBS at either site improves appendicular motor symptoms, but beneficial effects on axial manifestations of PD such as postural instability or gait dysfunction (PIGD) are less apparent. PPN has been introduced as a DBS target due to failure of GPi and STN DBS to improve PIGD. Small observational studies indicate improved PIGD with PPN DBS, but small blinded trials show only subjective reduction in falls with no other impact on PIGD or other PD manifestations. No single DBS target is superior to the others. Each target offers relative advantages. Further studies are needed to better define the roles of each target, particularly PPN. Choice of target should be individualized according to providers' preferences and patients' needs., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

The use of intramuscular injections of Botulinum neurotoxin A (BoNT-A) is common in the treatment of hypertonicity and movement disorders. Although most side effects are mild, systemic effects, manifested by generalized weakness distant from the site of injection, have been reported. Previously reported occurrences are discussed, and 3 new cases of patients, who developed systemic weakness after administration of BoNT-A (Botox), despite having tolerated similar injections on several previous occasions, are presented. A review of the literature and reported cases indicate that risk of developing systemic effects does not seem to be related to dose based on body weight. It may be more likely that risk for systemic effects is related to total injection dose and injection frequency. The results of our 3 patients would indicate that injections of greater than 600 units of Botox with follow-up injections occurring every 3 months may lead to an increased risk. We would recommend careful consideration of reinjection frequency if injections of greater than 600 units of Botox are given. Reduction in systemic side effects may occur if reinjection frequency occurs in intervals of 4 months or greater in these individuals.

Task-specific dystonias are primary focal dystonias characterized by excessive muscle contractions producing abnormal postures during selective motor activities that often involve highly skilled, repetitive movements. Historically these peculiar postures were considered psychogenic but have now been classified as forms of dystonia. Writer's cramp is the most commonly identified task-specific dystonia and has features typical of this group of disorders. Symptoms may begin with lack of dexterity during performance of a specific motor task with increasingly abnormal posturing of the involved body part as motor activity continues. Initially, the dystonia may manifest only during the performance of the inciting task, but as the condition progresses it may also occur during other activities or even at rest. Neurological exam is usually unremarkable except for the dystonia-related abnormalities. Although the precise pathophysiology remains unclear, increasing evidence suggests reduced inhibition at different levels of the sensorimotor system. Symptomatic treatment options include oral medications, botulinum toxin injections, neurosurgical procedures, and adaptive strategies. Prognosis may vary depending upon body part involved and specific type of task affected. Further research may reveal new insights into the etiology, pathophysiology, natural history, and improved treatment of these conditions.