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Zhang W, Jasinarachchi M, Seiderer L, Szmulewicz DJ, Roberts LJ. The Electrophysiological Findings in Spinocerebellar Ataxia Type 6: Evidence From 24 Patients. J Clin Neurophysiol 2023; 40:86-90. [PMID: 34038931 DOI: 10.1097/wnp.0000000000000855] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
PURPOSE Peripheral neuropathy has been reported commonly in several spinocerebellar ataxia (SCA) types. To date, there is a lack of robust evidence for neuropathy or neuronopathy in SCA type 6 (SCA6). Here, we aim to evaluate the presence of neuropathy or neuronopathy in a cohort of SCA6 patients. METHODS Twenty-four individuals with genetically confirmed SCA6 underwent detailed neurophysiological assessment. This included nerve conduction studies, and in some, cutaneous silent periods, blink reflexes, tilt table tests, quantitative sudomotor axon reflex tests, and somatosensory (median and tibial) evoked potentials. RESULTS Mean age was 56.1 years (range, 22-94 years) at the time of testing. Four patients were presymptomatic of SCA6 at recruitment. The mean disease duration of symptomatic patients was 11.9 years (range, 1-40 years). Most patients (79.2%, 19/24) had no neurophysiological evidence of a peripheral neuropathy. One with impaired glucose tolerance had mild, large, and small fiber sensorimotor polyneuropathy. One elderly patient had length-dependent axonal sensorimotor polyneuropathy. Two had minor sensory abnormalities (one had type II diabetes and previous chemotherapy). One other had minor small fiber abnormalities. Ten patients (41.7%) had median neuropathies at the wrist. All somatosensory evoked potential (15/15), and most autonomic function tests (13/14) were normal. CONCLUSIONS A large proportion of subjects (79.2%) in our cohort had no evidence of large or small fiber neuropathy. This study does not support the presence of neuropathy or neuronopathy as a common finding in SCA6 and confirms the importance of considering comorbidities as the cause of neurophysiological abnormalities.
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Affiliation(s)
- WenWen Zhang
- Department of Neurology, Alfred Hospital, Melbourne, Australia
| | - Mahi Jasinarachchi
- Department of Neurology and Neurological Research, St. Vincent's Hospital Melbourne, Melbourne, Australia; and
| | - Linda Seiderer
- Department of Neurology and Neurological Research, St. Vincent's Hospital Melbourne, Melbourne, Australia; and
| | - David J Szmulewicz
- Balance Disorders and Ataxia Service, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Leslie J Roberts
- Department of Neurology and Neurological Research, St. Vincent's Hospital Melbourne, Melbourne, Australia; and
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2
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Ramos-Languren LE, Rodríguez-Labrada R, Magaña JJ, Canales-Ochoa N, González-Zaldivar Y, Velázquez-Pérez L, González-Piña R. Involvement of the Auditory Pathway in Spinocerebellar Ataxia Type 7. NEURODEGENER DIS 2021; 20:185-192. [PMID: 34247167 DOI: 10.1159/000517213] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 05/13/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant disorder caused by a mutation in the ATXN7 gene. The involvement of the brainstem auditory pathway in pathogenesis of this disease has not been systematically assessed. AIM To determine involvement of the brainstem auditory pathway in SCA7 patients and its relationship to clinical features of the disease. METHODS In this case-control study, brainstem auditory-evoked potentials (BAEPs) were assessed in 12 SCA7 patients with clinical and molecular diagnosis, compared to 2 control groups of 16 SCA2 patients and 16 healthy controls. RESULTS SCA7 patients exhibited significant prolongation of I-wave and III-wave latencies, whereas SCA2 patients showed increased latencies for III and V waves and I-III interpeak interval. SCA7 patients with larger I-wave latencies exhibited larger CAG repeats, earlier onset age, and higher SARA scores, but in SCA2 cases, these were not observed. CONCLUSIONS BAEP tests revealed functional involvement of the auditory pathway in SCA7 (mainly at) peripheral portions, which gave new insights into the disease physiopathology different from SCA2 and may unravel distinct pathoanatomical effects of polyQ expansions in the central nervous system. SIGNIFICANCE These findings offer important insights into the distinctive disease mechanisms in SCA7 and SCA2, which could be useful for differential diagnosis and designing specific precision medicine approaches for both conditions.
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Affiliation(s)
- Laura E Ramos-Languren
- Psychobiology and Neurosciences Department, Psychology's Faculty, UNAM, Mexico City, Mexico
| | - Roberto Rodríguez-Labrada
- Center for Research and Rehabilitation of Hereditary Ataxias, Holguin, Cuba.,Cuban Centre for Neurosciences, Havana, Cuba
| | - Jonathan J Magaña
- Genetics Department, Genomic Medicine Laboratory, National Rehabilitation Institute LGII, Mexico City, Mexico
| | | | | | - Luis Velázquez-Pérez
- Center for Research and Rehabilitation of Hereditary Ataxias, Holguin, Cuba.,Cuban Academy of Sciences, Havana, Cuba
| | - Rigoberto González-Piña
- National Geriatrics Institute, Aging Biology Laboratory, Mexico City, Mexico.,America's University, Puebla 223 Col, Mexico City, Mexico
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3
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Chen ML, Lin CC, Rosenthal LS, Opal P, Kuo SH. Rating scales and biomarkers for CAG-repeat spinocerebellar ataxias: Implications for therapy development. J Neurol Sci 2021; 424:117417. [PMID: 33836316 DOI: 10.1016/j.jns.2021.117417] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 02/26/2021] [Accepted: 03/23/2021] [Indexed: 01/18/2023]
Abstract
Spinocerebellar ataxias (SCAs) are a group of dominantly-inherited cerebellar ataxias, among which CAG expansion-related SCAs are most common. These diseases have very high penetrance with defined disease progression, and emerging therapies are being developed to provide either symptomatic or disease-modifying benefits. In clinical trial design, it is crucial to incorporate biomarkers to test target engagement or track disease progression in response to therapies, especially in rare diseases such as SCAs. In this article, we review the available rating scales and recent advances of biomarkers in CAG-repeat SCAs. We divided biomarkers into neuroimaging, body fluid, and physiological studies. Understanding the utility of each biomarker will facilitate the design of robust clinical trials to advance therapies for SCAs.
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Affiliation(s)
- Meng-Ling Chen
- Department of Neurology, Columbia University, New York, NY, USA; Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA
| | - Chih-Chun Lin
- Department of Neurology, Columbia University, New York, NY, USA; Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA
| | - Liana S Rosenthal
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Puneet Opal
- Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; Department of Cellular and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Sheng-Han Kuo
- Department of Neurology, Columbia University, New York, NY, USA; Initiative for Columbia Ataxia and Tremor, Columbia University, New York, NY, USA.
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4
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I D, Proskokova T, Sikora N, Abramycheva N, Illarioshkin S. Spinocerebellar ataxia 17: full phenotype in a 42 CAG/CAA-repeats carrier. Zh Nevrol Psikhiatr Im S S Korsakova 2021; 121:100-105. [DOI: 10.17116/jnevro2021121121100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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5
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Abstract
Spinocerebellar ataxias (SCAs) are characterized by autosomal dominantly inherited progressive ataxia but are clinically heterogeneous due to variable involvement of non-cerebellar parts of the nervous system. Non-cerebellar symptoms contribute significantly to the burden of SCAs, may guide the clinician to the underlying genetic subtype, and might be useful markers to monitor disease. Peripheral neuropathy is frequently observed in SCA, but subtype-specific features and subclinical manifestations have rarely been evaluated. We performed a multicenter nerve conduction study with 162 patients with genetically confirmed SCA1, SCA2, SCA3, and SCA6. The study proved peripheral nerves to be involved in the neurodegenerative process in 82 % of SCA1, 63 % of SCA2, 55 % of SCA3, and 22 % of SCA6 patients. Most patients of all subtypes revealed affection of both sensory and motor fibers. Neuropathy was most frequently of mixed type with axonal and demyelinating characteristics in all SCA subtypes. However, nerve conduction velocities of SCA1 patients were slower compared to other genotypes. SCA6 patients revealed less axonal damage than patients with other subtypes. No influence of CAG repeat length or biometric determinants on peripheral neuropathy could be identified in SCA1, SCA3, and SCA6. In SCA2, earlier onset and more severe ataxia were associated with peripheral neuropathy. We proved peripheral neuropathy to be a frequent site of the neurodegenerative process in all common SCA subtypes. Since damage to peripheral nerves is readily assessable by electrophysiological means, nerve conduction studies should be performed in a longitudinal approach to assess these parameters as potential progression markers.
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Wang X, Wang H, Xia Y, Jiang H, Shen L, Wang S, Shen R, Xu Q, Luo X, Tang B. Spinocerebellar ataxia type 6: Systematic patho-anatomical study reveals different phylogenetically defined regions of the cerebellum and neural pathways undergo different evolutions of the degenerative process. Neuropathology 2016; 30:501-14. [PMID: 20113406 DOI: 10.1111/j.1440-1789.2009.01094.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Spinocerebellar ataxia type 6 is a late onset autosomal dominantly inherited ataxic disorder, and previous patho-anatomical studies have only reported neurodegeneration in SCA6 as being confined to the cerebellar cortex, dentate nucleus and inferior olive. However, the characteristics of cerebellar symptoms and many poorly understood "extracerebellar" symptoms reveal the three cerebellar regions and the corresponding precerebellar nuclei may undergo differing evolution of the degenerative process, and a more widespread brainstem degeneration in SCA6. We carried out a detailed immunohistochemical study in two SCA6 patients who had rather early onset and short disease duration with 25 CAG repeats, which is atypical for SCA-6. We investigated the severity of neurodegeneration in each of the cerebellar regions and the corresponding precerebellar nuclei, and further characterize the extent of brain degeneration. This study confirmed that vestibulocerebellar, spinocerebellum and pontocerebellar are consistent targets of the pathological process of SCA6, but the severity of neurodegeneration in each of them was different. Vestibulocerebellum and the inferior cerebellar peduncle undergo the most severe neurodegeneration, while neurodegeneration in the pontocerebellar is less severe. Furthermore, we observed obvious neurodegeneration in layers II and III of the primary motor cortex, vestibular nuclei, inferior olivary nucleus, nucleus proprius and posterior spinocerebellar tract. Our detailed postmortem findings confirmed that SCA6 was not a simple "pure" cerebellar disease, but a complex neurodegenerative disease in which the three cerebellar regions underwent different evolutions of neurodegeneration process, and the corresponding precerebellar nuclei and the neural pathway were all involved.
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Affiliation(s)
- Xuejing Wang
- Department of Neurology, Xiangya Hospital,Department of Anatomy & Neurobiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, andDepartment of Anatomy, Qing Dao University, QingDao, Shandong, China
| | - Hui Wang
- Department of Neurology, Xiangya Hospital,Department of Anatomy & Neurobiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, andDepartment of Anatomy, Qing Dao University, QingDao, Shandong, China
| | - Yujun Xia
- Department of Neurology, Xiangya Hospital,Department of Anatomy & Neurobiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, andDepartment of Anatomy, Qing Dao University, QingDao, Shandong, China
| | - Hong Jiang
- Department of Neurology, Xiangya Hospital,Department of Anatomy & Neurobiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, andDepartment of Anatomy, Qing Dao University, QingDao, Shandong, China
| | - Lu Shen
- Department of Neurology, Xiangya Hospital,Department of Anatomy & Neurobiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, andDepartment of Anatomy, Qing Dao University, QingDao, Shandong, China
| | - Shoubiao Wang
- Department of Neurology, Xiangya Hospital,Department of Anatomy & Neurobiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, andDepartment of Anatomy, Qing Dao University, QingDao, Shandong, China
| | - Ruowu Shen
- Department of Neurology, Xiangya Hospital,Department of Anatomy & Neurobiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, andDepartment of Anatomy, Qing Dao University, QingDao, Shandong, China
| | - Qian Xu
- Department of Neurology, Xiangya Hospital,Department of Anatomy & Neurobiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, andDepartment of Anatomy, Qing Dao University, QingDao, Shandong, China
| | - Xuegang Luo
- Department of Neurology, Xiangya Hospital,Department of Anatomy & Neurobiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, andDepartment of Anatomy, Qing Dao University, QingDao, Shandong, China
| | - Beisha Tang
- Department of Neurology, Xiangya Hospital,Department of Anatomy & Neurobiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, andDepartment of Anatomy, Qing Dao University, QingDao, Shandong, China
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7
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Liang L, Chen T, Wu Y. The electrophysiology of spinocerebellar ataxias. Neurophysiol Clin 2016; 46:27-34. [DOI: 10.1016/j.neucli.2015.12.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 12/29/2015] [Indexed: 12/18/2022] Open
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Horiuchi M. [How does the physician interpret the patient's narrative as it relates to the physical exam?; A case of spinocerebellar degeneration with peripheral neuropathy]. ACTA ACUST UNITED AC 2014; 103:482-5. [PMID: 24724390 DOI: 10.2169/naika.103.482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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9
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Rüb U, Schöls L, Paulson H, Auburger G, Kermer P, Jen JC, Seidel K, Korf HW, Deller T. Clinical features, neurogenetics and neuropathology of the polyglutamine spinocerebellar ataxias type 1, 2, 3, 6 and 7. Prog Neurobiol 2013; 104:38-66. [PMID: 23438480 DOI: 10.1016/j.pneurobio.2013.01.001] [Citation(s) in RCA: 228] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 01/22/2013] [Accepted: 01/31/2013] [Indexed: 12/18/2022]
Abstract
The spinocerebellar ataxias type 1 (SCA1), 2 (SCA2), 3 (SCA3), 6 (SCA6) and 7 (SCA7) are genetically defined autosomal dominantly inherited progressive cerebellar ataxias (ADCAs). They belong to the group of CAG-repeat or polyglutamine diseases and share pathologically expanded and meiotically unstable glutamine-encoding CAG-repeats at distinct gene loci encoding elongated polyglutamine stretches in the disease proteins. In recent years, progress has been made in the understanding of the pathogenesis of these currently incurable diseases: Identification of underlying genetic mechanisms made it possible to classify the different ADCAs and to define their clinical and pathological features. Furthermore, advances in molecular biology yielded new insights into the physiological and pathophysiological role of the gene products of SCA1, SCA2, SCA3, SCA6 and SCA7 (i.e. ataxin-1, ataxin-2, ataxin-3, α-1A subunit of the P/Q type voltage-dependent calcium channel, ataxin-7). In the present review we summarize our current knowledge about the polyglutamine ataxias SCA1, SCA2, SCA3, SCA6 and SCA7 and compare their clinical and electrophysiological features, genetic and molecular biological background, as well as their brain pathologies. Furthermore, we provide an overview of the structure, interactions and functions of the different disease proteins. On the basis of these comprehensive data, similarities, differences and possible disease mechanisms are discussed.
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Affiliation(s)
- Udo Rüb
- Dr. Senckenberg Chronomedical Institute, Goethe-University, Theodor-Stern-Kai 7, D-60590 Frankfurt/Main, Germany.
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Abstract
The autosomal dominant spinocerebellar ataxias (SCA) are a genetically heterogeneous group of neurodegenerative disorders characterized by progressive motor incoordination, in some cases with ataxia alone and in others in association with additional progressive neurological deficits. Spinocerebellar ataxia type 6 (SCA6) is the prototype of a pure cerebellar ataxia, associated with a severe form of progressive ataxia and cerebellar dysfunction. SCA6, originally classified as such by Zhuchenko et al. (1997), is caused by a CAG repeat expansion in the CACNA1A gene which encodes the α1A subunit of the P/Q-type voltage-gated calcium channel. SCA6 is one of ten polyglutamine-encoding CAG nucleotide repeat expansion disorders comprising other neurodegenerative disorders such as Huntington's disease. The present review describes clinical, genetic, and pathological manifestations associated with this illness. Currently, there is no treatment for this neurodegenerative disease. Successful therapeutic strategies must target a valid pathological mechanism; thus, understanding the underlying mechanisms of disease is crucial to finding a proper treatment. Hence, this chapter will discuss as well the molecular mechanisms possibly associated with SCA6 pathology and their implication for the development of future treatment.
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Affiliation(s)
- Ana Solodkin
- Department of Neurology, University of Chicago Medical Center, Chicago, IL 606337, USA.
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11
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Gierga K, Schelhaas HJ, Brunt ER, Seidel K, Scherzed W, Egensperger R, de Vos RAI, den Dunnen W, Ippel PF, Petrasch-Parwez E, Deller T, Schöls L, Rüb U. Spinocerebellar ataxia type 6 (SCA6): neurodegeneration goes beyond the known brain predilection sites. Neuropathol Appl Neurobiol 2009; 35:515-27. [DOI: 10.1111/j.1365-2990.2009.01015.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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12
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Chen JT, Lin YY, Lee YC, Soong BW, Wu ZA, Liao KK. Prolonged central motor conduction time of lower limb muscle in spinocerebellar ataxia 6. J Clin Neurosci 2004; 11:381-3. [PMID: 15080952 DOI: 10.1016/j.jocn.2003.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2003] [Accepted: 08/11/2003] [Indexed: 10/26/2022]
Abstract
We investigated the function of corticospinal tract in spinocerebellar ataxia 6 (SCA6) by measuring the central motor conduction time (CMCT). Motor evoked potentials (MEP) of tibialis anterior (TA) muscle were elicited by magnetic stimulation to motor cortex and spinal cord in 9 SCA6 patients and 10 normal height- and age-matched subjects. CMCT in lower limb of SCA6 patients (18.1+/-1.9 ms) was significantly prolonged than that of the normal subjects (15.0+/-1.0 ms) ((p < 0.001). The prolonged CMCT was well correlated with the duration of disease (p = 0.005), but MEP amplitudes and stimulation intensities were not significantly different. These results indicate that the corticospinal tract function is also impaired and correlate with the disease duration in SCA6.
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Affiliation(s)
- Jen-Tse Chen
- Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan
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13
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Lee YC, Chen JT, Liao KK, Wu ZA, Soong BW. Prolonged cortical relay time of long latency reflex and central motor conduction in patients with spinocerebellar ataxia type 6. Clin Neurophysiol 2003; 114:458-62. [PMID: 12705426 DOI: 10.1016/s1388-2457(02)00378-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE Spinocerebellar ataxia type 6 (SCA6) is a neurodegenerative disorder characterized by a slowly progressive ataxia and dysarthria. Anatomically. SCA6 was said to affect only the cerebellum. However, ithasbeen argued that SCA6 may involve widespread regions of the brain. This study was designed to investigate the electrophysiological functions of the central nervous system in patients affected with SCA6. METHODS Nine patients with SCA6 and 10 normal, age-matched control subjects were included in the study. The motor evoked potentials, somatosensory evoked potentials, and long latency reflex (LLR) of the hand muscle were measured to evaluate the functions of the central nervous system. RESULTS Significantly delayed LLR, as well as prolonged cortical relay time (CRT) and central motor conduction time (CMCT) of the hand muscle, were noted in the patients with SCA6. CONCLUSIONS The prolongation of CMCT andCRT suggested that SCA6 disturbed the functions of the corticospinal tract and the transcortical polysynaptic pathways from the sensory to motorcortices. It seems likely that the CNS dysfunction caused by SCA6 is not limited to the structures that are anatomically abnormal. Furthermore, the prolongation of CMCT alone does not seem to suffice to differentiate between various types of autosomal dominant cerebellar ataxias. Molecular analysis is indispensable for the diagnosis of different genetic types of SCA.
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Affiliation(s)
- Yi-Chung Lee
- The Neurological Institute, Taipei Veterans General Hospital, #201, Sec. 2, Shih-Pai Road, Peitou District, Taipei 112, Taiwan
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