Childhood-onset cerebellar ataxia in Japan: A questionnaire-based survey.

OBJECTIVE: The diagnosis of childhood-onset cerebellar ataxia (CA) is often challenging due to variations in symptoms and etiologies. Despite the known regional differences in the prevalence of etiologies underlying CA, the frequency and characteristics of CA in Japan remain unclear. We conducted a questionnaire-based survey to identify the clinical characteristics of childhood-onset CA in the Japanese population. MATERIALS AND METHODS: Questionnaires were sent to 1,103 board-certified pediatric neurologists in Japan from 2016 to 2017. The primary survey requested the number of patients with CA under care, and the follow-up secondary questionnaire requested additional clinical characteristics of the patients. RESULTS: The primary survey obtained 578 responses (response rate, 52.4%) on 385 patients with CA, including 171 diagnosed and 214 undiagnosed cases (diagnostic rate, 44.4%). The most frequent etiology was dentatorubropallidoluysian atrophy (DRPLA), followed by mitochondrial disorders and encephalitis. The secondary survey obtained the clinical characteristics of 252 cases (119 diagnosed and 133 undiagnosed cases). Multiple logistic regression analysis revealed that a younger age at onset, hearing issues, and short stature were associated with a higher risk of remaining undiagnosed with CA in Japan. CONCLUSIONS: The diagnostic rate of childhood-onset CA in the current study was comparable to those reported in other countries. The high prevalence of autosomal dominant ataxia, especially DRPLA, was a signature of CA in Japan. These data offer insights into the characteristics of childhood-onset CA in the Japanese population.

A case series of hereditary cerebellar ataxias in a highly consanguineous population from Northeast Brazil.

BACKGROUND: There are few studies reporting characteristics of patients with cerebellar ataxias in the Brazilian population. The aim of this study was to provide a detailed neurological description of patients with hereditary ataxia followed by a neurology outpatient service in Brazil. METHODS: Neurological and clinical evaluation of patients with hereditary ataxia was performed at a neurology service outpatient clinic of a hospital in Northeast Brazil between October 2013 and January 2015. RESULTS: A total of 47 patients had ataxia as the main symptom. A high prevalence of consanguinity was found in the population studied (40.4%). Mean age was 38.4 ±â€¯15.3 years, mean age at disease onset was 25.6 ±â€¯17.3 years, mean disease duration was 12.8 ±â€¯9.7 years, and mean score on the Scale for the Assessment and Rating of Ataxia (SARA) was 18.4 ±â€¯7.7. Patients with recessive pattern of inheritance were younger, had earlier age at disease onset and greater severity of ataxia, measured by the SARA. Diagnosis was confirmed by molecular analysis, laboratory exams or biopsy in 42.56% (n = 20) of these patients. The most prevalent diseases were: Friedreich's ataxia in 35% (n = 7), Niemann-Pick type C (NPC) in 15% (n = 3), and ataxia with oculomotor apraxia type 2 in 15% (n = 3). CONCLUSIONS: In contrast with other studies, our prevalence of recessive ataxias was much higher than that of dominant ataxias. These findings might be explained by the high number of patients living in rural areas with a higher rate of consanguineous marriages, absence of a dominant ataxia founder effect or difficult access to healthcare system.

Otoneurological findings prevalent in hereditary ataxias / Alterações otoneurológicas prevalentes nas ataxias hereditárias

ABSTRACT Objective To describe and compare the vestibular findings most evident among the hereditary ataxias, as well as correlate their clinical features with the nervous structures affected in this disease. Methods Seventy-five patients were evaluated and underwent a case history, otorhinolaryngological and vestibular assessments. Results Clinically, the patients commonly had symptoms of gait disturbances (67.1%), dizziness (47.3%), dysarthria (46%) and dysphagia (36.8%). In vestibular testing, alterations were predominantly evident in caloric testing (79%), testing for saccadic dysmetria (51%) and rotational chair testing (47%). The presence of alterations occurred in 87% of these patients. A majority of the alterations were from central vestibular dysfunction (69.3%). Conclusion This underscores the importance of the contribution of topodiagnostic labyrinthine evaluations for neurodegenerative diseases as, in most cases, the initial symptoms are otoneurological; and these evaluations should also be included in the selection of procedures to be performed in clinical and therapeutic monitoring.

RESUMO Objetivo Descrever e comparar os achados vestibulares mais evidentes entre a ataxia hereditária, bem como correlacionar seus aspectos clínicos com o estudo das estruturas nervosas afetadas nesta doença. Métodos 75 pacientes foram avaliados e submetidos aos seguintes procedimentos: anamnese, avaliação otorrinolaringológica e vestibular. Resultados Clinicamente, os pacientes apresentaram sintomas de distúrbios da marcha (67,1%), tonturas (47,3%), disartria (46%) e disfagia (36,8%). No teste vestibular, as alterações foram predominantemente evidentes no teste calórico (79%), dismetria sacádicas (51%) e no teste rotatório (47%). A presença de alterações ocorreu em 87% dos pacientes. A maioria das alterações observadas foram da disfunção vestibular central (69,3%). Conclusão O estudo ressalta a importância da contribuição da avaliação labiríntica no topodiagnóstico para doenças neurodegenerativas, uma vez que, na maioria dos casos, os sintomas iniciais são otoneurológicos, e essas avaliações também devem ser incluídas na seleção de procedimentos a serem realizados no monitoramento clínico e terapêutico.

Hereditary ataxias: overview.

The hereditary ataxias are a highly heterogeneous group of disorders phenotypically characterized by gait ataxia, incoordination of eye movements, speech, and hand movements, and usually associated with atrophy of the cerebellum. There are more than 35 autosomal dominant types frequently termed spinocerebellar ataxia and typically having adult onset. The most common subtypes are spinocerebellar ataxia 1, 2, 3, 6, and 7, all of which are nucleotide repeat expansion disorders. Autosomal recessive ataxias usually have onset in childhood; the most common subtypes are -Friedreich, ataxia-telangiectasia, ataxia with oculomotor apraxia type 1, and ataxia with oculomotor apraxia type 2. Four autosomal recessive types have dietary or biochemical treatment modalities (ataxia with vitamin E deficiency, cerebrotendinous xanthomatosis, Refsum, and coenzyme Q10 deficiency), whereas there are no specific treatments for other ataxias. Diagnostic genetic testing is complicated because of the large number of relatively uncommon subtypes with extensive phenotypic overlap. However, the best testing strategy is based on assessing relative frequencies, ethnic predilections, and recognition of associated phenotypic features such as seizures, visual loss, or associated movement abnormalities.

Missense mutations in the AFG3L2 proteolytic domain account for ∼1.5% of European autosomal dominant cerebellar ataxias.

Spinocerebellar ataxia type 28 is an autosomal dominant form of cerebellar ataxia (ADCA) caused by mutations in AFG3L2, a gene that encodes a subunit of the mitochondrial m-AAA protease. We screened 366 primarily Caucasian ADCA families, negative for the most common triplet expansions, for point mutations in AFG3L2 using DHPLC. Whole-gene deletions were excluded in 300 of the patients, and duplications were excluded in 129 patients. We found six missense mutations in nine unrelated index cases (9/366, 2.6%): c.1961C>T (p.Thr654Ile) in exon 15, c.1996A>G (p.Met666Val), c.1997T>G (p.Met666Arg), c.1997T>C (p.Met666Thr), c.2011G>A (p.Gly671Arg), and c.2012G>A (p.Gly671Glu) in exon 16. All mutated amino acids were located in the C-terminal proteolytic domain. In available cases, we demonstrated the mutations segregated with the disease. Mutated amino acids are highly conserved, and bioinformatic analysis indicates the substitutions are likely deleterious. This investigation demonstrates that SCA28 accounts for ∼3% of ADCA Caucasian cases negative for triplet expansions and, in extenso, to ∼1.5% of all ADCA. We further confirm both the involvement of AFG3L2 gene in SCA28 and the presence of a mutational hotspot in exons 15-16. Screening for SCA28, is warranted in patients who test negative for more common SCAs and present with a slowly progressive cerebellar ataxia accompanied by oculomotor signs.

A clinical epidemiological study in 2169 patients with vertigo.

OBJECTIVE: To investigate the clinical epidemiological characteristics of vertigo. METHODS: Retrospective study on 2169 patients with vertigo (male 883, female 1286, 7-90 years old) of the past 20 years. RESULTS: More than 50 kinds of causative diseases were recognized. Peripheral, central, and unclassified vertigo took up 33.8, 17.2 and 26.8% of patients, respectively, while vertigo of unknown origin was around 22.2%. Vertigo patients increased according to age and reached its peak in the 1960s among all three categories. Although female patients were seemingly overwhelmed the male, no significant difference in the incidence rate was recognized in two genders. Only 2.2% (48 cases) of the total vertigo patients were children, while elders occupied 30.0% (650 cases). Compared to younger patients, the elderly have a high tendency of suffering central vertigo. CONCLUSION: Vertigo attacks patients in all age spans, with various causative diseases.

Aprataxin gene mutations in Tunisian families.

The authors report clinical and genetic study of 13 patients from three unrelated Tunisian families with an early onset cerebellar ataxia associated with oculomotor apraxia. Cerebellar ataxia with oculomotor apraxia 1 (AOA1) represents a clinically heterogeneous disease caused by mutations in the aprataxin gene. Two novel mutations were identified, the complete deletion of the gene, which seems to not correlate with an increased severity of the disease, and a splice mutation on the acceptor splice site of exon 7.

Phenotypic features and genetic findings in sacsin-related autosomal recessive ataxia in Tunisia.

BACKGROUND: Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a clinically homogenous disorder reported in Quebec caused by mutations in the SACS gene (chromosome 13q12). Recently, we identified a Tunisian kindred demonstrating linkage to the ARSACS locus. OBJECTIVE: To report clinical, neurophysiological, and nerve biopsy findings in patients with autosomal recessive cerebellar ataxia related to the SACS gene in Tunisia. PATIENTS AND METHODS: Genetic linkage analysis of patients with early-onset autosomal recessive cerebellar ataxia allowed the identification of 4 families from which 18 patients demonstrated linkage to the ARSACS locus. The patients were evaluated according to the International Cooperative Ataxia Rating Scale. Peripheral nerve conduction, sensory evoked potentials, and nerve biopsy were performed in most patients. RESULTS: The mean age at onset was 4.5 years. The clinical phenotype was stereotyped and associated with a progressive cerebellar syndrome, a pyramidal syndrome with brisk knee reflexes, and Babinski sign and absent ankle reflexes. The course of the disease varied among patients. Sensory evoked potentials showed severe posterior column involvement. Peripheral nerve investigations demonstrated axonal and demyelinating neuropathy. Four mutations, 2 missense and 2 nonsense, were found. CONCLUSION: In Tunisia, autosomal recessive cerebellar ataxia related to the SACS gene demonstrated a homogenous phenotype and heterogeneous allelic mutations.

Early-onset ataxia with ocular motor apraxia and hypoalbuminemia: the aprataxin gene mutations.

BACKGROUND: Early-onset ataxia with hypoalbuminemia is regarded as a variant form of Friedreich ataxia in Japan. Early-onset ataxia with hypoalbuminemia and ataxia with ocular motor apraxia have been considered as the same clinical entity because of the recent identification of a common mutation in the aprataxin gene. A new clinical entity named early-onset ataxia with ocular motor apraxia and hypoalbuminemia (EAOH) has been proposed to explain these two diseases. OBJECTIVE: To disclose the clinical features of EAOH and to identify the mutations in the aprataxin gene in six patients in four Japanese families with EAOH. METHODS: The clinical features, laboratory findings, sural nerve biopsy results, and brain MRI or CT findings for these patients were evaluated, and molecular analysis was performed, which involved sequencing of the aprataxin gene directly or use of the subcloning method. RESULTS: Cerebellar ataxia and peripheral neuropathy were noted in all six patients. Ocular motor apraxia was observed in five patients; two of these patients had obvious head thrust. Choreiform movements of the limbs and mental deterioration were observed in five patients. Although foot deformity was noted in five patients, kyphoscoliosis was noted only in one patient. In all patients, hypoalbuminemia and hypercholesterolemia were evident, and brain MRI or CT showed marked cerebellar atrophy. Nerve biopsy revealed depletion of large myelinated fibers in three of the five patients examined. Molecular analysis of the aprataxin gene revealed an insertion mutation (insT at nt167) and two missense mutations (A-to-G transition at nt80 and C-to-T transition at nt95, the former being novel). CONCLUSION: We found clinical heterogeneity in the patients with EAOH in this study. With the disease course, the choreiform movements tended to reduce in degree, and hypoalbuminemia became evident. Molecular analysis identified one insertion and two missense mutations including a novel missense one, which was located at a highly conserved amino acid residue in the aprataxin gene product.

Linkage to chromosome 13q11-12 of an autosomal recessive cerebellar ataxia in a Tunisian family.

OBJECTIVE: To report the clinical findings and the genetic linkage mapping of an autosomal recessive cerebellar ataxia associated to peripheral neuropathy, showing an early onset cerebellar ataxia with retained tendon reflexes (EOCA) phenotype. BACKGROUND: EOCA is a clinical syndrome delimited by Harding distinguished from Friedreich's ataxia (FA) mainly by the preservation of tendon reflexes. Molecular genetic study of patients with EOCA has demonstrated genetic heterogeneity. A form of autosomal recessive spastic ataxia has been described in Charlevoix Saguenay area in Quebec (ARSACS); the gene responsible has been mapped to chromosome 13q. METHODS: Genetic linkage analysis was performed on 18 members of a large family including 8 of 9 members with EOCA. After exclusion of FA and ataxia with vitamin E deficiency loci as well as loci of autosomal dominant cerebellar ataxias, we performed a linkage analysis to markers of 13q11-12 region. RESULTS: The 9 affected members of this family showed stereotyped clinical features with cerebellar ataxia, pyramidal syndrome, and a variable degree of axonal peripheral neuropathy. Linkage was detected between the disease locus and the microsatellite marker D13S232. Surrounding markers to D13S232 confirmed the linkage and showed the homozygosity of the affected members. CONCLUSION: The family reported here showed the same locus as autosomal recessive spastic ataxia Charlevoix Saguenay disease.

Hereditary ataxias and spastic paraplegias: methodological aspects of a prevalence study in Portugal.

A project for studying the prevalence of hereditary ataxias (HA) and familial spastic paraplegias (FSP) in Portugal was set up in 1993. The ascertainment of patients in previous prevalence studies relied mainly on the information of hospital admissions and out-patient contacts with the neurology and other related departments at central hospitals covering the whole region surveyed. Many patients might be overlooked if large populations were studied using this method, since registers at central hospitals are very incomplete and for most part not yet computerized. On the other hand HA and FSP are rare diseases appearing in family clusters, and it would be unreasonable to undertake a sample survey based upon a suitable frame of the Portuguese population. Therefore we decided to carry out a two-phase prevalence survey at district level, involving the collaboration of all physicians working in the district health institutions and the population, in the screening of eligible subjects in phase 1. All subjects screened as positive were examined by a neurologist in phase 2. This method provided a direct estimate of false positives and false negatives were all patients also examined in phase 2, who came to our knowledge using other sources of information. The prevalence of hereditary ataxias and spastic paraplegias in the pilot district was 6.4 per 100,000 inhabitants. The sensitivity of the screening procedure was 81.2% and the predictive value of a positive screening was 25%. Considering the geographically circumscribed district nature of the populations to be studied, the comprehensive sources of case identification used and the high adherence of the health professionals involved, we believe that this method can be widely used, particularly in countries with similar health care services.

[Epidemiology of spinocerebellar degeneration in Tottori prefecture].

1. A prevalence study of spinocerebellar degeneration (SCD) was carried out in Tottori prefecture. Seventy two patients were found and the prevalence rate was 11.6 per 100,000 population. When age adjusted to the country's population, the figure was 10.2. These rates was higher than those reported previously in Japan. The prevalence ratio for male and female was 1.4:1. 2. Twenty four cases of SCD who died were analysed for the study of long prognosis. The average age at death was 60.7 +/- 9.8 and the mean duration of illness was 5.3 +/- 2.8 years. The leading causes of death were bronchopneumonia in seven cases, feebleness in four cases, sudden death in four cases, malignant neoplasms in three cases and suffocation in two cases.