[Spinocerebellar ataxia 1--clinical study of 17 patients in a large pedigree].
We studied a large pedigree with dominant spinocerebellar ataxia, genetically and clinically. At now, 27 members over 5 generations have been affected. Linkage study for the disease locus to D6S89 in a total of 44 individuals showed maximum lod scores of 3.99 at theta = 0.000. This result indicates that the disease locus of this pedigree locates near D6S89 on chromosome 6p (SCA 1). We studied 17 patients clinically. Mean age at onset was 37.7 +/- 8.6, and mean duration after onset was 11.3 +/- 6.8 years. Their clinical features were characterized by progressive ataxia, pyramidal involvement with hyperreflexia or spasticity, and mild posterior column involvement. Mild gaze nystagmus at early stage became unclear with the progress of illness. The frequent signs in the advanced stage were diffuse amyotropy, twitching of face or tongue, bulbar palsy, slow saccade, external ophthalmoparesis, mydriasis, coarse postural tremor, and dementia with emotional disturbance. There are so much clinical similarities between our pedigree and other SCA 1 pedigrees in the literature. Generally, SCA 1 shows hyperreflexia, spasticity, and terminal slow saccade. On the other hand, non-SCA 1 type OPCA is characterized by progressive hyporeflexia, slow eye movement from early stage, and frequent choreoathetosis. Gaze nystagmus, external ophthalmoparesis, amyotrophy, and spasticity are common in both SCA 1 and Machado-Joseph disease (MJD). However, they are more frequent in MJD than SCA 1. Moreover, extrapyramidal signs, such as dystonia, are rare is SCA 1. Based on these difference, SCA 1 could be clinically differentiated from other similar hereditary ataxias.
Sasaki
H
H
Department of Neurology, Hokkaido University School of Medicine, Sapporo, Japan.
Wakisaka
A
A
Koyama
T
T
Hamada
T
T
Shima
K
K
Tashiro
K
K
Hashimoto
K
K
Miyagishi
T
T
D000328:Adult; D001921:Brain / Q000473:pathology; D002896:Chromosomes, Human, Pair 6; D005192:Family Health; D005260:Female; D006801:Humans; D008126:Lod Score; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D013132:Spinocerebellar Degenerations / Q000175:diagnosis / Q000235:genetics*