Frequency of spinocerebellar ataxia mutations in patients with multiple system atrophy.

PURPOSE: Investigate single nucleotide variants and short tandem repeats in 39 genes related to spinocerebellar ataxia in clinical and pathologically defined cohorts of multiple system atrophy. METHODS: Exome sequencing was conducted in 28 clinical multiple system atrophy patients to identify single nucleotide variants in spinocerebellar ataxia-related genes. Novel variants were validated in two independent disease cohorts: 86 clinically diagnosed multiple system atrophy patients and 166 pathological multiple system atrophy cases. Expanded repeat alleles in spinocerebellar ataxia genes were evaluated in 36 clinically diagnosed multiple system atrophy patients, and CAG/CAA repeats in TATA-Box Binding Protein (TBP, causative of SCA17) were screened in 216 clinical and pathological multiple system atrophy patients and 346 controls. RESULTS: No known pathogenic spinocerebellar ataxia single nucleotide variants or pathogenic range expanded repeat alleles of ATXN1, ATXN2, ATXN3, CACNA1A, AXTN7, ATXN8OS, ATXN10, PPP2R2B, and TBP were detected in any clinical multiple system atrophy patients. However, four novel variants were identified in four spinocerebellar ataxia-related genes across three multiple system atrophy patients. Additionally, four multiple system atrophy patients (1.6%) and one control (0.3%) carried an intermediate length 41 TBP CAG/CAA repeat allele (OR = 4.11, P = 0.21). There was a significant association between the occurrence of a repeat length of longer alleles (> 38 repeats) and an increased risk of multiple system atrophy (OR = 1.64, P = 0.03). CONCLUSION: Occurrence of TBP CAG/CAA repeat length of longer alleles (> 38 repeats) is significantly associated with increased multiple system atrophy risk. This discovery warrants further investigation and supports a possible genetic overlap of multiple system atrophy with SCA17.

Development and Validation of the Orthostatic Tremor Severity and Disability Scale (OT-10).

BACKGROUND: Limited tools are available for the assessment of orthostatic tremor severity and disability. OBJECTIVES: To develop and validate a self-administered orthostatic tremor scale. METHODS: After expert consensus and literature review generating a list of 42 items, the scale was developed and modified for validation after a patient focus group, multiple rounds of Delphi panels, and cognitive interviews. Clinimetric evaluations included assessing content validity, internal consistency, measurement error and reliability, construct validity, and concurrent validity anchored on the examiner's Clinical Global Impression score. RESULTS: Eleven items ranked on a Likert scale from 0 (no disability/severity) to 5 (maximal disability/severity) were evaluated in 54 orthostatic tremor patients (16 men and 38 women; mean age: 69.17 ± 9.64 years; disease duration: 13.83 ± 11.24 years) to probe severity and disability over the preceding 1-week period. The 11-item scale showed good internal consistency (Cronbach's alpha = 0.863) and acceptable (>0.40) item-to-total correlation. However, one item was removed at the final Delphi panel because of significant floor effect, poor item-to-total correlation, and poor factor-loading, leaving the scale with 10 items (10-item Orthostatic Tremor Severity and Disability Scale). Test-retest reliability at 2 weeks was excellent (two-way random intraclass correlation coefficient > 0.90), and the individual item test-retest reliability showed good agreement, with a threshold weighted kappa >0.60 for all items. Exploratory factor analyses revealed a parsimonious two-factor construct accounting for 57.7% of the scale's variance. The 10-item Orthostatic Tremor Severity and Disability Scale scores correlated with the CGI. CONCLUSIONS: The self-administered 10-item Orthostatic Tremor Severity and Disability Scale scale is valid and reliable for capturing orthostatic tremor-related severity and disability. © 2020 International Parkinson and Movement Disorder Society.

Global Survey on Telemedicine Utilization for Movement Disorders During the COVID-19 Pandemic.

BACKGROUND: The COVID-19 pandemic restricted usual healthcare management for movement-disorders patients, with a consequent upsurge in telemedicine to bridge the gap. OBJECTIVE: To assess global telemedicine usage in the context of the pandemic. METHODS: The Movement Disorder Society (MDS) Telemedicine Study Group surveyed telemedicine experts from 40 countries across all continents in March-April 2020. Four domains of telemedicine were assessed: legal regulations, reimbursement, clinical use, and barriers; comparing emerging responses to the pandemic versus the baseline scenario. RESULTS: All forms of telemedicine for movement disorders increased globally, irrespective of country income categorization, as an immediate response to the pandemic. This was aided by widespread availability of technology and updated government regulations. However, privacy concerns, lack of reimbursement, limited access, and lack of telemedicine training were barriers highlighted worldwide. CONCLUSIONS: Questions remain about the longevity and extent of changes in regulations and reimbursement regarding telemedicine in the aftermath of the pandemic. © 2020 International Parkinson and Movement Disorder Society.

Sensitivity and Specificity of Diagnostic Criteria for Progressive Supranuclear Palsy.

BACKGROUND: In 2017, the International Parkinson and Movement Disorder Society put forward new clinical criteria for the diagnosis of PSP, recognizing diverse PSP phenotypes. In this study, we compared the sensitivity and specificity of the new criteria with the National Institutes of Neurological Disease and Society for Progressive Supranuclear Palsy criteria at different times. METHODS: Patients with clinical parkinsonism, clinical and/or neuropathological diagnosis of PSP, were identified from the Society for Progressive Supranuclear Palsy brain bank. All patients had neuropathologic diagnoses and detailed clinical examination performed by a neurologist at 1 of the 3 Mayo Clinic sites, in Florida, Arizona, and Minnesota. Clinical symptoms and signs were abstracted retrospectively in a blinded fashion and used to determine whether patients met either diagnostic criterion. Patients were divided into early and late disease stage groups using a 3-year cutoff. RESULTS: A total of 129 patients were included, of whom 66 had PSP pathology (51%). The remainder had other neurodegenerative diseases. The overall sensitivity of the International Parkinson and Movement Disorder Society criteria was 87.9%, compared with 45.5% for the National Institutes of Neurological Disease and Society for Progressive Supranuclear Palsy criteria, whereas the specificity of the International Parkinson and Movement Disorder Society probable PSP criteria was 85.7%, compared with 90.5% for the National Institutes of Neurological Disease and Society for Progressive Supranuclear Palsy. Individual patients were noted to have features of multiple PSP phenotypes. CONCLUSION: The International Parkinson and Movement Disorder Society criteria recognize several phenotypes of progressive supranuclear palsy and hence have higher sensitivity than the previous criteria. © 2019 International Parkinson and Movement Disorder Society.

An unusual presentation of late-onset Alexander's disease with slow orthostatic tremor and a novel GFAP variant.

Alexander disease (AxD) is a leukodystrophy, described in infantile, juvenile and adult onset forms, due to mutations in the glial fibrillary acid protein (GFAP) gene. Adult-onset AxD (AOAD) has a range of clinical and radiographic phenotypes with the oldest reported onset in the seventh decade.We report a case of AOAD, with onset in the eighth decade, presenting with slow variant orthostatic tremor, which has not been previously described. Genetic analysis revealed a GFAP variant (c.1158C>A) that has not been previously reported. Our case serves to expand the diagnostic spectrum of AOAD both clinically and genetically.

Telemedicine Use for Movement Disorders: A Global Survey.

BACKGROUND: Telemedicine is increasingly used to care for patients with movement disorders, but data regarding its global use are limited. INTRODUCTION: To obtain baseline international data about telemedicine use among movement disorder clinicians. METHODS: An online survey was sent to all 6,056 Movement Disorder Society members in 2015. Scope, reimbursement, and perceived quality of telemedicine were assessed. RESULTS: There were 549 respondents (9.1% overall response rate) from 83 countries. Most (85.8%) were physicians, and most (70.9%) worked in an academic or university practice. Half of respondents (n = 287, from 57 countries) used telemedicine for clinical care; activities included e-mail (63.2%), video visits (follow-up [39.7%] and new [35.2%]), and video-based education (35.2%). One hundred five respondents personally conducted video visits, most frequently to outpatient clinics (53.5%), patient homes (30.8%), and hospital inpatients (30.3%). The most common challenges were a limited neurological examination (58.9%) and technological difficulties (53.3%), and the most common benefits were reduced travel time (92.9%) and patient costs (60.1%). The most frequent reimbursements were none (39.0%), public insurance (24.5%), and patient payment (9.3%). Half of respondents planned to use telemedicine in the future, and three-quarters were interested in telemedicine education. CONCLUSIONS: More than 250 respondents around the world engage in telemedicine for movement disorders; most perceived benefit for patients, despite challenges and reimbursement for clinicians. Formal instruction on telemedicine is highly desired. Although the survey response was low and possibly biased to over represent those with telemedicine experience, the study provides baseline data for future comparison and to improve telemedicine delivery.

Thalamic deep brain stimulation for orthostatic tremor: A multicenter international registry.

BACKGROUND: We report the accumulated experience with ventral intermediate nucleus deep brain stimulation for medically refractory orthostatic tremor. METHODS: Data from 17 patients were reviewed, comparing presurgical, short-term (0-48 months), and long-term (≥48 months) follow-up. The primary end point was the composite activities of daily living/instrumental activities of daily living score. Secondary end points included latency of symptoms on standing and treatment-related complications. RESULTS: There was a 21.6% improvement (P = 0.004) in the composite activities of daily living/instrumental activities of daily living score, which gradually attenuated (12.5%) in the subgroup of patients with an additional long-term follow-up (8 of 17). The latency of symptoms on standing significantly improved, both in the short-term (P = 0.001) and in the long-term (P = 0.018). Three patients obtained no/minimal benefit from the procedure. CONCLUSIONS: Deep brain stimulation of the ventral intermediate nucleus was, in general, safe and well tolerated, yielding sustained benefit in selected patients with medically refractory orthostatic tremor. © 2017 International Parkinson and Movement Disorder Society.

Alien Hand Syndrome.

Alien hand syndrome (AHS) is a rare disorder of involuntary limb movement together with a sense of loss of limb ownership. It most commonly affects the hand, but can occur in the leg. The anterior (frontal, callosal) and posterior variants are recognized, with distinguishing clinical features and anatomical lesions. Initial descriptions were attributed to stroke and neurosurgical operations, but neurodegenerative causes are now recognized as most common. Structural and functional imaging and clinical studies have implicated the supplementary motor area, pre-supplementary motor area, and their network connections in the frontal variant of AHS, and the inferior parietal lobule and connections in the posterior variant. Several theories are proposed to explain the pathophysiology. Herein, we review the literature to update advances in the understanding of the classification, pathophysiology, etiology, and treatment of AHS.

MAPT haplotype H1G is associated with increased risk of dementia with Lewy bodies.

INTRODUCTION: The MAPT H1 haplotype has been associated with several neurodegenerative diseases. We were interested in exploring the role of MAPT haplotypic variation in risk of dementia with Lewy bodies (DLB). METHOD: We genotyped six MAPT haplotype tagging SNPs and screened 431 clinical DLB cases, 347 pathologically defined high-likelihood DLB cases, and 1049 controls. RESULT: We performed haplotypic association tests and detected an association with the protective H2 haplotype in our combined series (odds ratio [OR] = 0.75). We fine-mapped the locus and identified a relatively rare haplotype, H1G, that is associated with an increased risk of DLB (OR = 3.30, P = .0017). This association was replicated in our pathologically defined series (OR = 2.26, P = .035). DISCUSSION: These results support a role for H1 and specifically H1G in susceptibility to DLB. However, the exact functional variant at the locus is still unknown, and additional studies are warranted to fully explain genetic risk of DLB at the MAPT locus.

National Randomized Controlled Trial of Virtual House Calls for People with Parkinson's Disease: Interest and Barriers.

BACKGROUND: Delivering specialty care remotely directly into people's homes can enhance access for and improve the healthcare of individuals with chronic conditions. However, evidence supporting this approach is limited. MATERIALS AND METHODS: Connect.Parkinson is a randomized comparative effectiveness study that compares usual care of individuals with Parkinson's disease in the community with usual care augmented by virtual house calls with a Parkinson's disease specialist from 1 of 18 centers nationally. Individuals in the intervention arm receive four virtual visits from a Parkinson's disease specialist over 1 year via secure, Web-based videoconferencing directly into their homes. All study activities, including recruitment, enrollment, and assessments, are conducted remotely. Here we report on interest, feasibility, and barriers to enrollment in this ongoing study. RESULTS: During recruitment, 11,734 individuals visited the study's Web site, and 927 unique individuals submitted electronic interest forms. Two hundred ten individuals from 18 states enrolled in the study from March 2014 to June 2015, and 195 were randomized. Most participants were white (96%) and college educated (73%). Of the randomized participants, 73% had seen a Parkinson's disease specialist within the previous year. CONCLUSIONS: Among individuals with Parkinson's disease, national interest in receiving remote specialty care directly into the home is high. Remote enrollment in this care model is feasible but is likely affected by differential access to the Internet.

Smile without euphoria induced by deep brain stimulation: a case report.

Poststroke central pain (PSCP) can be a debilitating medication-refractory disorder. We report a single case where right unilateral ventral capsule/ventral striatum (VC/VS) deep brain stimulation was used to treat PSCP and inadvertently induced a smile without euphoria. The patient was a 69 year-old woman who had a stroke with resultant dysesthesia and allodynia in her left hemibody and also a painful left hemibody dystonia. In her case, VC/VS stimulation induced a smile phenomenon, but without a euphoric sensation. This phenomenon was different from the typical smile responses we have observed in obsessive-compulsive disorder cases. This difference was considered to be possibly attributable to impairment in the emotional smile pathway.

Numb Chin Syndrome.

"Numb chin syndrome" (NCS) refers to new-onset numbness of the lower lip and chin within the distribution of the mental or inferior alveolar nerves. While this focal numbness may be downplayed or even overlooked by patients and clinicians, in the right clinical scenario this may be the presenting symptom of an underlying malignancy. In the absence of any obvious, temporally related dental cause, there are certain conditions that clinicians should consider including orofacial and systemic malignancies as well as several inflammatory disorders. Thorough diagnostic evaluation should always be performed when no clear cause is evident. This paper will discuss the differential, recommended evaluations, and the prognosis, for a patient presenting with NCS.

The past, present, and future of telemedicine for Parkinson's disease.

Travel distance, growing disability, and uneven distribution of doctors limit access to care for most Parkinson's disease (PD) patients worldwide. Telemedicine, the use of telecommunications technology to deliver care at a distance, can help overcome these barriers. In this report, we describe the past, present, and likely future applications of telemedicine to PD. Historically, telemedicine has relied on expensive equipment to connect single patients to a specialist in pilot programs in wealthy nations. As the cost of video conferencing has plummeted, these efforts have expanded in scale and scope, now reaching larger parts of the world and extending the focus from care to training of remote providers. Policy, especially limited reimbursement, currently hinders the growth and adoption of these new care models. As these policies change and technology advances and spreads, the following will likely develop: integrated care networks that connect patients to a wide range of providers; education programs that support patients and health care providers; and new research applications that include remote monitoring and remote visits. Together, these developments will enable more individuals with PD to connect to care, increase access to expertise for patients and providers, and allow more-extensive, less-expensive participation in research.

Median nerve ultrasound in diabetic peripheral neuropathy with and without carpal tunnel syndrome.

INTRODUCTION: Median nerve ultrasound shows increased cross-sectional area (CSA) in carpal tunnel syndrome (CTS) and diabetic peripheral neuropathy (PN). The role of ultrasound in diagnosing CTS superimposed on diabetic PN is unknown. The objective of this study is to evaluate ultrasound for diagnosis of CTS in diabetic PN. METHODS: Prospective recruitment of diabetics with electrodiagnostically proven PN, subdivided into cases (with CTS) or controls (without CTS). The gold standard for CTS was clinical diagnosis. NCS were correlated with blinded median nerve CSA ultrasound measurements. RESULTS: Eight cases (CTS) and eight controls (no CTS) were recruited. Nerve conduction studies (NCS): Median nerve distal latencies (antidromic sensory; palmar; lumbrical motor; and lumbrical motor to ulnar interosseous difference) were significantly prolonged in CTS cases. No ultrasound measurement (distal median CSA, wrist-forearm ratio, wrist-forearm difference) reached significance to detect CTS. Area under the curve was greatest for lumbrical distal latency by receiver operator characteristic analysis (0.85). CONCLUSIONS: In this pilot study, NCS may be superior to ultrasound for identification of superimposed CTS in diabetic PN patients, but larger numbers are needed for confirmation.

Episodic Ataxias: Primary and Secondary Etiologies, Treatment, and Classification Approaches.

Background: Episodic ataxia (EA), characterized by recurrent attacks of cerebellar dysfunction, is the manifestation of a group of rare autosomal dominant inherited disorders. EA1 and EA2 are most frequently encountered, caused by mutations in KCNA1 and CACNA1A. EA3-8 are reported in rare families. Advances in genetic testing have broadened the KCNA1 and CACNA1A phenotypes, and detected EA as an unusual presentation of several other genetic disorders. Additionally, there are various secondary causes of EA and mimicking disorders. Together, these can pose diagnostic challenges for neurologists. Methods: A systematic literature review was performed in October 2022 for 'episodic ataxia' and 'paroxysmal ataxia', restricted to publications in the last 10 years to focus on recent clinical advances. Clinical, genetic, and treatment characteristics were summarized. Results: EA1 and EA2 phenotypes have further broadened. In particular, EA2 may be accompanied by other paroxysmal disorders of childhood with chronic neuropsychiatric features. New treatments for EA2 include dalfampridine and fampridine, in addition to 4-aminopyridine and acetazolamide. There are recent proposals for EA9-10. EA may also be caused by gene mutations associated with chronic ataxias (SCA-14, SCA-27, SCA-42, AOA2, CAPOS), epilepsy syndromes (KCNA2, SCN2A, PRRT2), GLUT-1, mitochondrial disorders (PDHA1, PDHX, ACO2), metabolic disorders (Maple syrup urine disease, Hartnup disease, type I citrullinemia, thiamine and biotin metabolism defects), and others. Secondary causes of EA are more commonly encountered than primary EA (vascular, inflammatory, toxic-metabolic). EA can be misdiagnosed as migraine, peripheral vestibular disorders, anxiety, and functional symptoms. Primary and secondary EA are frequently treatable which should prompt a search for the cause. Discussion: EA may be overlooked or misdiagnosed for a variety of reasons, including phenotype-genotype variability and clinical overlap between primary and secondary causes. EA is highly treatable, so it is important to consider in the differential diagnosis of paroxysmal disorders. Classical EA1 and EA2 phenotypes prompt single gene test and treatment pathways. For atypical phenotypes, next generation genetic testing can aid diagnosis and guide treatment. Updated classification systems for EA are discussed which may assist diagnosis and management.

Outpatient Motor Retraining for Functional Movement Disorder: Predictors of a Favorable Short-Term Response.

Background: Treating functional movement disorder (FMD) with motor retraining is effective but resource intensive. Objectives: Identify patient, disease, and program variables associated with favorable treatment outcomes. Methods: Retrospective review of the 1 week intensive outpatient FMD program at Mayo Clinic in Minnesota from February 2019 to August 2021. Outcomes included patient-reported measures (Canadian Occupational Performance Measure-Performance and Satisfaction subscales [COPM-P and COPM-S, range 0-10] and Global Rating of Change [GROC, -7 to +7]) and a retrospective investigator-rated scale (0-3, worse/not improved to significantly improved/resolved). Linear regression models identified variables predicting favorable outcomes. Results: Participants (n = 201, 74% female, mean age = 46) had median FMD duration of 24 months. The commonest FMD subtypes were gait disorder (65%), tremor (41%) and weakness (17%); 53% had ≥2 subtypes. Most patients (88%) completed a therapeutic screening process before program entry. Patient-reported outcomes at the end of the week improved substantially (COPM-P average change 3.8 ± 1.9; GROC post-program average 5.5 ± 1.7). Available investigator-rated outcomes from short-term follow-up were also positive (102/122 [84%] moderately to significantly improved/resolved). Factors predicting greater improvement in COPM-P were completing therapeutic screening, higher number of non-motor symptoms, shorter FMD duration, earlier program entry, lower baseline COPM scores, and (among screened patients) higher GROC between therapeutic screening and program start. Conclusion: Patients with diverse FMD subtypes improved substantially over a 1 week period. Utilization of therapeutic screening and greater improvement between therapeutic screening and program start were novel predictors of favorable outcomes. Non-motor symptoms did not preclude positive responses, although patients with predominant non-motor burden were excluded.

Deep Brain Stimulator Device Infection: The Mayo Clinic Rochester Experience.

Background: Deep brain stimulator (DBS)-related infection is a recognized complication that may significantly alter the course of DBS therapy. We describe the Mayo Clinic Rochester experience with DBS-related infections. Methods: This was a retrospective study of all adults (≥18 years old) who underwent DBS-related procedures between 2000 and 2020 at the Mayo Clinic Rochester. Results: There were 1087 patients who underwent 1896 procedures. Infection occurred in 57/1112 (5%) primary DBS implantations and 16/784 (2%) revision surgeries. The median time to infection (interquartile range) was 2.1 (0.9-6.9) months. The odds of infection were higher with longer operative length (P = .002), higher body mass index (BMI; P = .006), male sex (P = .041), and diabetes mellitus (P = .002). The association between infection and higher BMI (P = .002), male sex (P = .016), and diabetes mellitus (P = .003) remained significant in a subgroup analysis of primary implantations but not revision surgeries. Infection was superficial in 17 (23%) and deep in 56 (77%) cases. Commonly identified pathogens were Staphylococcus aureus (65%), coagulase-negative staphylococci (43%), and Cutibacterium acnes (45%). Three device management approaches were identified: 39 (53%) had complete device explantation, 20 (27%) had surgical intervention with device retention, and 14 (19%) had medical management alone. Treatment failure occurred in 16 (23%) patients. Time-to-event analysis showed fewer treatment failures with complete device explantation (P = .015). Only 1 individual had complications with brain abscess at failure. Conclusions: Primary DBS implantations had higher rates of infection compared with revision surgeries. Complete device explantation was favored for deep infections. However, device salvage was commonly attempted and is a reasonable approach in select cases given the low rate of complications.

Efficacy and Safety of N-Acetyl-l-Leucine in Children and Adults With GM2 Gangliosidoses.

BACKGROUND AND OBJECTIVES: GM2 gangliosidoses (Tay-Sachs and Sandhoff diseases) are rare, autosomal recessive, neurodegenerative diseases with no available symptomatic or disease-modifying treatments. This clinical trial investigated N-acetyl-l-leucine (NALL), an orally administered, modified amino acid in pediatric (≥6 years) and adult patients with GM2 gangliosidoses. METHODS: In this phase IIb, multinational, open-label, rater-blinded study (IB1001-202), male and female patients aged ≥6 years with a genetically confirmed diagnosis of GM2 gangliosidoses received orally administered NALL for a 6-week treatment period (4 g/d in patients ≥13 years, weight-tiered doses for patients 6-12 years), followed by a 6-week posttreatment washout period. For the primary Clinical Impression of Change in Severity analysis, patient performance on a predetermined primary anchor test (the 8-Meter Walk Test or the 9-Hole Peg Test) at baseline, after 6 weeks on NALL, and again after a 6-week washout period was videoed and evaluated centrally by blinded raters. Secondary outcomes included assessments of ataxia, clinical global impression, and quality of life. RESULTS: Thirty patients between the age of 6 and 55 years were enrolled. Twenty-nine had an on-treatment assessment and were included in the primary modified intention-to-treat analysis. The study met its CI-CS primary end point (mean difference 0.71, SD = 2.09, 90% CI 0.00, 1.50, p = 0.039), as well as secondary measures of ataxia and global impression. NALL was safe and well tolerated, with no serious adverse reactions. DISCUSSION: Treatment with NALL was associated with statistically significant and clinically relevant changes in functioning and quality of life in patients with GM2 gangliosidosis. NALL was safe and well tolerated, contributing to an overall favorable risk:benefit profile. NALL is a promising, easily administered (oral) therapeutic option for these rare, debilitating diseases with immense unmet medical needs. TRIAL REGISTRATION INFORMATION: The trial is registered with ClinicalTrials.gov (NCT03759665; registered on November 30, 2018), EudraCT (2018-004406-25), and DRKS (DRKS00017539). The first patient was enrolled on June 7, 2019. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that NALL improves outcomes for patients with GM2 gangliosidoses.

Focal and other unusual presentations of facioscapulohumeral muscular dystrophy.

INTRODUCTION: Facioscapulohumeral dystrophy (FSHD) presents classically with facial and shoulder-girdle weakness. We report focal atypical presentations of FSHD. Our aim was to identify focal/unusual phenotypes in genetically confirmed FSHD cases. METHODS: We undertook a retrospective review of an academic center database of the period from 1996 to 2011. Of 139 FSHD cases, 7 had atypical genetically confirmed disease. Clinical data were abstracted. RESULTS: Seven cases (4 men) had a mean age of 37 years at onset (range 18-63 years) and mean 43 years at diagnosis (range 20-74 years). Presenting symptoms were monomelic lower limb (n = 3) or upper limb (n = 2) atrophy, or axial weakness (n = 2). Five patients had focal weakness on examination. CK was normal to borderline high. Two patients had a relative with FSHD. Coexistent unusual features included dyspnea (n = 1), S1 radicular pain with calf atrophy (n = 2), and peripheral neuropathy (n = 1). Almost all patients had myopathic EMG changes. DNA analysis showed a D4Z4 EcoRI fragment size ranging from 20 to 37 kilobases. CONCLUSIONS: FSHD may present with focal weakness, dyspnea and myopathic EMG changes. These findings should raise the possibility of FSHD.

Neuropathological features of corticobasal degeneration presenting as corticobasal syndrome or Richardson syndrome.

Patients with corticobasal degeneration can present with several different clinical syndromes, making ante-mortem diagnosis a challenge. Corticobasal syndrome is the clinical phenotype originally described for corticobasal degeneration, characterized by asymmetric rigidity and apraxia, cortical sensory deficits, dystonia and myoclonus. Some patients do not develop these features, but instead have clinical features consistent with the Richardson syndrome presentation of progressive supranuclear palsy, characterized by postural instability, early unexplained falls, vertical supranuclear gaze palsy, symmetric motor disability and dysphagia. The aim of this study was to identify differences in corticobasal degeneration presenting with corticobasal syndrome (n = 11) or Richardson syndrome (n = 15) with respect to demographic, clinical and neuropathological features. Corticobasal degeneration cases were also compared with patients with pathologically proven progressive supranuclear palsy with Richardson syndrome (n = 15). Cases with corticobasal degeneration, regardless of presentation, shared histopathological and tau biochemical characteristics, but they had differing densities of tau pathology in neuroanatomical regions that correlated with their clinical presentation. In particular, those with corticobasal syndrome had greater tau pathology in the primary motor and somatosensory cortices and putamen, while those with Richardson syndrome had greater tau pathology in limbic and hindbrain structures. Compared with progressive supranuclear palsy, patients with corticobasal degeneration and Richardson syndrome had less neuronal loss in the subthalamic nucleus, but more severe neuronal loss in the medial substantia nigra and greater atrophy of the anterior corpus callosum. Clinically, they had more cognitive impairment and frontal behavioural dysfunction. The results suggest that Richardson syndrome can be a clinicopathological presentation of corticobasal degeneration. Atrophy of anterior corpus callosum may be a potential neuroimaging marker to differentiate corticobasal degeneration from progressive supranuclear palsy in patients with Richardson syndrome.