Peripheral neuropathy in late onset spinocerebellar ataxia

We studied 10 patients with late onset spinocerebellar ataxia including electrophysiological and muscle biopsy examinations. Nerve conduction studies of eight patients revealed axonal neuropathy, and six cases also showed signs of the involvement of the lower motor neuron. In 9 patients quantitative analysis of single motor unit potentials (MUPs) of the tibialis anterior or biceps brachii muscles showed mild to severe neuropathic changes and in all 10 patients the histopathological examination of the tibialis anterior showed mild to severe neuropathic changes. Neither nerve conduction studies, quantitative MUP analysis, nor histological findings of the muscle were related to the severity of duration of the disease.     

Sensory neuropathy in infantile onset spinocerebellar ataxia (IOSCA)

Infantile onset spinocerebellar ataxia with sensory neuropathy is a new, inherited multisystem disorder discovered in 19 Finnish patients. In order to define the neuropathy of the disease, we measured sensory nerve action potentials and nerve conduction velocities in 18 patients, and recorded somatosensory evoked potentials (SEP) in 10 patients and performed a sural nerve biopsy in 13 patients. The fixed and teased nerve fascicles were examined by light and electron microscopy, and the whole transverse section of a nerve fascicle was photographed and enlarged for morphometric measurements. Our investigation revealed an early onset, rapidly progressive axonal neuropathy: the sensory action potentials were decreased after the age of 2 and a severe loss of mainly large myelinated fibers was found. © 1994 John & Sons, Inc.     

早发型脊髓小脑共济失调6型家系的神经病理学研究

目的 对我国首次报道的经基因诊断明确的早发型脊髓小脑共济失调6型(spinocerebellar ataxia 6,SCA6)家系进行神经病理学研究.方法 对经基因诊断明确的一个SCA6家系中的2例患者进行尸检,分别取小脑上蚓部、齿状核、下橄榄核等部位进行HE染色、尼氏染色、Golgi染色、Calbindin免疫组织化学以及电镜的检测,研究早发型SCA6中枢神经系统的病理改变.结果 早发型SCA6患者的小脑皮质浦肯野细胞出现严重的神经退行性改变,齿状核、下橄榄核神经元以及大脑皮质中央前回也受到累及,而脊髓相对保存无明显的神经病理学改变.结论 早发型SCA6患者中枢神经系统存在较为严重的神经退行性改变,主要发生在小脑皮质、齿状核以及下橄榄核,这些病理改变随病程的延长而逐渐加重.     

Gastrointestinal disorders in hyperkinetic movement disorders and ataxia

BackgroundGastrointestinal (GI) disorders have been thoroughly investigated in hypokinetic disorders such as Parkinson's disease, but much less is known about GI disorders in hyperkinetic movement disorders and ataxia. The aim of this review is to draw attention to the GI disorders that are associated with these movement disorders.MethodsReferences for this systematic review were identified by searches of PubMed through May 2020. Only publications in English were reviewed.ResultsData from 249 articles were critically reviewed, compared, and integrated. The most frequently reported GI symptoms overall in hyperkinetic movement disorders and ataxia are dysphagia, sialorrhea, weight changes, esophago-gastritis, gastroparesis, constipation, diarrhea, and malabsorption. We report in detail on the frequency, characteristics, pathophysiology, and management of GI symptoms in essential tremor, restless legs syndrome, chorea, and spinocerebellar ataxias. The limited available data on GI disorders in dystonias, paroxysmal movement disorders, tardive dyskinesias, myoclonus, and non-SCA ataxias are also summarized.ConclusionThe purpose of our systematic review is to draw attention that, although primarily motor disorders, hyperkinetic movement disorders and ataxia can involve the GI system. Raising awareness about the GI symptom burden in hyperkinetic movement disorders and ataxia could contribute to a new research interest in that field, as well as improved patient care.     

Symptom onset of spinocerebellar ataxia type 10 in pregnancy and puerperium

Spinocerebellar ataxia type 10 is an autosomal dominant neurodegenerative disorder. It was initially described in Mexican families presenting with ataxia and epilepsy, with or without polyneuropathy, pyramidal signs and cognitive symptoms. The authors report three patients from the same family who were asymptomatic until gestation and puerperium, when they developed symptoms and signs suggestive of the syndrome. Genetic diagnosis was made in the three patients. The authors hypothesize that hormonal changes are likely to influence the manifestation of the condition.     

Adult onset tic disorders

BACKGROUND: Tic disorders presenting during adulthood have infrequently been described in the medical literature. Most reports depict adult onset secondary tic disorders caused by trauma, encephalitis, and other acquired conditions. Only rare reports describe idiopathic adult onset tic disorders, and most of these cases represent recurrent childhood tic disorders. OBJECTIVE: To describe a large series of patients with tic disorders presenting during adulthood, to compare clinical characteristics between groups of patients, and to call attention to this potentially disabling and underrecognised neurological disorder. METHODS: Using a computerised database, all patients with tic disorders who presented between 1988 and 1998 to the movement disorders clinic at Columbia-Presbyterian Medical Center after the age of 21 were identified. Patients' charts were retrospectively reviewed for demographic information, age of onset of tics, tic phenomenology, distribution, the presence of premonitory sensory symptoms and tic suppressibility, family history, and associated psychiatric features. These patients' videotapes were reviewed for diagnostic confirmation and information was obtained about disability, course, and response to treatment in a structured follow up interview. RESULTS: Of 411 patients with tic disorders in the database, 22 patients presented for the first time with tic disorders after the age of 21. In nine patients, detailed questioning disclosed a history of previous childhood transient tic disorder, but in 13 patients, the adult onset tic disorder was new. Among the new onset cases, six patients developed tics in relation to an external trigger, and could be considered to have secondary tic disorders. The remaining patients had idiopathic tic disorders. Comparing adult patients with recurrent childhood tics and those with new onset adult tics, the appearance of the tic disorder, the course and prognosis, the family history of tic disorder, and the prevalence of obsessive-compulsive disorder were found to be similar. Adults with new onset tics were more likely to have a symptomatic or secondary tic disorder, which in this series was caused by infection, trauma, cocaine use, and neuroleptic exposure. CONCLUSIONS: Adult onset tic disorders represent an underrecognised condition that is more common than generally appreciated or reported. The clinical characteristics of adults newly presenting to a movement disorder clinic with tic disorders are reviewed, analysed, and discussed in detail. Clinical evidence supports the concept that tic disorders in adults are part of a range that includes childhood onset tic disorders and Tourette's syndrome.     

A neuropathological study at autopsy of early onset spinocerebellar ataxia 6

Spinocerebellar ataxia type 6 (SCA6) is a late-onset, autosomal dominantly inherited ataxic disorder, and most previous clinical studies consider SCA6 to be a “pure” cerebellar ataxia. We carried out a detailed pathoanatomical study at autopsy of two patients, brother and sister, with genetically confirmed SCA6. The disease in both patients was early onset and short, which is atypical for SCA6. We observed severe neurodegeneration in the cerebellum, dentate nucleus and olivary nuclei. Both patients showed evidence of synaptic modification in the cerebellar cortex, which morphologically confirmed the existence of retrograde and anterograde trans-synaptic degeneration secondary to the cerebellar cortical lesion. Furthermore, our study shows for the first time that neurodegeneration in SCA6 occurs in the spinal cord. Finally, our postmortem study confirms that SCA6 is not a simple “pure” cerebellar disease, but a complex neurodegenerative condition in which many extracerebellar structures are involved.     

Disturbance of rapid eye movement sleep in spinocerebellar ataxia type 2.

Five genetically confirmed spinocerebellar ataxia type 2 (SCA2) patients were admitted to our sleep laboratory for two all-night video-polysomnographies. A standard montage was used, including electroencephalography, vertical and horizontal electrooculography, electromyography of mental, submental, and tibialis anterior muscles, and respiratory monitoring. Four of five SCA2 patients had insufficient muscle atonia during rapid eye movement (REM) sleep. All patients exhibited myoclonic jerks during REM sleep, while elaborated behavior was not observed in the video. Abnormal motor control during sleep with periodic leg movements and REM sleep without atonia occurs frequently in SCA2. This finding may reflect a dysfunction of dopaminergic and/or brainstem and cerebellar outflow pathways.     

Pimavanserin use in a movement disorders clinic: a single-center experience

Background

Parkinson’s disease psychosis (PDP) is a disabling non-motor symptom of Parkinson’s disease (PD) that is challenging to treat. Dopamine receptor blockers (DRB) are used to treat PDP, though these may be associated with adverse effects, including worsening of Parkinsonism. Pimavanserin, a selective 5-HT_2A receptor inverse agonist, was recently FDA-approved for treatment of PDP; however, there is limited information on its long-term use in PDP patients.

Methods

A retrospective chart review of patients prescribed pimavanserin was performed in August, 2017. Data on demographics, psychotic features, sleep, and adverse effects was collected using a semi-structured telephone interview with patients or caregivers. Hallucination severity (HS) was quantified as mild (<?1 episode/week), moderate (1/week to <?1/day), or severe (daily/continuous).

Results

Seventeen patients consented to participate in the study; 16 were diagnosed with PDP, 1 with Lewy body dementia. Fourteen had co-morbid cognitive impairment/dementia. The mean duration of Parkinsonism was 11.8?±?8.0 years, with 2.6?±?1.9 years of psychosis. Eleven of the seventeen patients reported improvement of hallucinations of which 5/8 were initiated on pimavanserin monotherapy, and 6/9 reported improvement of HS with combination of DRB. Six of nine patients prescribed DRB were able to discontinue this medication after introduction of pimavanserin. Four patients discontinued medications (2, no benefit; 1, spontaneous resolution; 1, cost). No major side effects were reported, and two patients noted subjective improvement of sleep.

Conclusion

In our series based on a small sample size, pimavanserin is well-tolerated and effective as both monotherapy and adjuvant treatment for moderate to severe. This medication can facilitate reduction or cessation of DRB medication.

     

Vergence disorders in patients with spinocerebellar ataxia 3/Machado-Joseph disease: a synoptophore study

Diplopia, a common symptom in spinocerebellar ataxia 3/Machado-Joseph disease (SCA3/MJD) cases, is not always due to asymmetric ophthalmoplegia. We found a Japanese SCA3/MJD family, in which three patients clearly had an impairment of divergence eye movement. We thus quantitatively examined the vergence ranges in eight Japanese SCA3/MJD cases using the synoptophore test. An impairment of the vergence eye movements was found in all patients, and the vergence impairment pattern, but not the ophthalmoplegia pattern, was found to be compatible with the diplopia pattern. The diplopia in SCA3/MJD cases is, therefore, attributed, at least in part, to the impairment of the vergence eye movements.     

Identification of a novel Twinkle mutation in a family with infantile onset spinocerebellar ataxia by whole exome sequencing

Whole exome sequencing combined with homozygosity mapping comprises a genetic diagnostic tool to identify genetic defects in families with multiple affected members, compatible with presumed autosomal recessively inherited neurometabolic/neurogenetic disease. These tools were applied to a family with two individuals manifesting ataxia, associated with peripheral sensory neuropathy, athetosis, seizures, deafness, and ophthalmoplegia. A novel homozygous missense mutation c.1366C>G (L456V) in C10orf2 (the Twinkle gene) was identified, confirming infantile onset spinocerebellar ataxia in the probands. Signs in infantile onset spinocerebellar ataxia follow a fairly distinct pattern, affecting early development, followed by ataxia and loss of skills. However, this very rare disease was previously reported only in Finland. We suggest that infantile onset spinocerebellar ataxia should be more frequently considered in the differential diagnosis of neurometabolic diseases in childhood. Next-generation sequencing and its use along with homozygosity mapping offer highly promising techniques for molecular diagnosis, especially in small families affected with very rare neurometabolic disorders such as infantile onset spinocerebellar ataxia.     

Early onset, non fluctuating spinocerebellar ataxia and a novel missense mutation in CACNA1A gene

Mutations in the brain-specific P/Q type Ca2+ channel alpha1 subunit gene, CACNA1A, have been identified in three clinically distinct disorders, spinocerebellar ataxia type 6 (SCA6), episodic ataxia type 2 (EA2), and familial hemiplegic migraine type 1 (FHM1). SCA6 is associated with small expansions of a CAG repeat at the 3' end of the gene, while point mutations are mostly responsible for its two allelic disorders, FHMI and EA2. From the electrophysiological point of view, while FHMI mutations lead to a gain of function [Tottene A, Fellin T, Pagnutti S, Luvisetto S, Striessnig J, Fletcher C, et al. Familial hemiplegic migraine mutations increase Ca2+ influx through single human CaV2.1 channels and decrease maximal CaV2.1 current density in neurons. Proc Natl Acad Sci 99 (20) (2002) 13284-13289.], EA2 mutations usually generate a loss of channel function [Guida S, Trettel F, Pagnutti S, Mantuano E, Tottene A, Veneziano L, et al. Complete loss of P/Q calcium channel activity caused by a CACNA1A missense mutation carried by patients with episodic ataxia type 2. Am J Hum Genet 68 (3) (2001) 759-764, Wappl E, Koschak A, Poteser M, Sinnegger MJ, Walter D, Eberhart A, et al. Functional consequences of P/Q-type Ca2+ channel Cav2.1 missense mutations associated with episodic ataxia type 2 and progressive ataxia. J Biol Chem 277 (9) (2002) 6960-6966.]. In the present study, we describe a child affected by permanent non-fluctuating limb and trunk ataxia with a quite early age of onset. Interestingly, the size of the CACNA1A triplet repeat region in the patient is within the normal range while he carries a novel de novo missense mutation in this gene, p.R1664Q. Although functional data are not available, based on the literature data indicating that severe reductions in P/Q-type channel activity favour episodic and/or progressive ataxic symptoms [Wappl E, Koschak A, Poteser M, Sinnegger MJ, Walter D, Eberhart A, et al. Functional consequences of P/Q-type Ca2+ channel Cav2.1 missense mutations associated with episodic ataxia type 2 and progressive ataxia. J Biol Chem 2002;277(9):6960-6966.], we hypothesize that the functional consequence of the mutation here identified is a partial loss of the Ca channel function. In conclusion, the clinical and molecular findings reported here suggest the opportunity to screen for point mutation in this gene, even patients with a clinical phenotype for some aspects slightly different from the typical picture more commonly associated to SCA6, EA2 or FHM1 diseases.     

Subtle rapid eye movement sleep abnormalities in presymptomatic spinocerebellar ataxia type 2 gene carriers

Rapid eye movement (REM) sleep disorders are commonly associated to patients with spinocerebellar ataxia type 2 (SCA2); however, these abnormalities have not been studied in presymptomatic gene carriers. To determine whether the REM sleep pathology is detectable before clinical manifestation of SCA2 and evaluate it as a preclinical biomarker, we studied 36 presymptomatic SCA2 individuals and 36 controls by video‐polysomnography (VPSG) and sleep questionnaires. Presymptomatic subjects showed significant decrease of REM sleep percentage, REMs density, total sleep time, and sleep efficiency. Aging effect on REM sleep percentage was significant in both groups. There was no correlation between cytosine‐adenine‐guanine (CAG) repeat length and REM sleep. Our findings identified the REM sleep pathology as a prominent herald sign of SCA2, conferring a special importance to VPSG as a sensitive neurophysiological tool to detect early changes associated with SCA2, which contributes to the understanding of disease pathophysiology and the development of therapeutic trials focused on the preclinical disease stage. © 2010 Movement Disorder Society.     

Electrophysiologic characterization in spinocerebellar ataxia 17

The authors performed a multimodal electrophysiologic evaluation in nine patients belonging to four SCA17 (spinocerebellar ataxia type 17) families. Peripheral nerve and visual system were not involved. Brainstem auditory evoked potentials were constantly abnormal with central type lesions. Magnetic motor evoked potentials were abnormal only in the lower limbs, suggesting a length-dependent involvement of the pyramidal tract. Somatosensory evoked potentials were abnormal in almost all our patients, and abnormalities were consistent with a somatosensory pathway involvement along the brainstem.