Rinsho Shinkeigaku (Clinical Neurology)

Case Report

SCA6 presenting parkinsonism without ataxia
-A case report-

Shinichi Takeshima, M.D.1), Ikuko Takeda, M.D.1)4), Keitaro Kobatake, M.D.2), Toru Yamashita, M.D., Ph.D.3), Koji Abe, M.D., Ph.D.3) and Masaru Kuriyama, M.D., Ph.D.1)

1)Department of Neurology, Brain Attack Center Ota Memorial Hospital
2)Kobatake Hospital
3)Department of Neurology, Okayama University
4)Present Address: Department of Clinical Neuroscience & Therapeutics, Hiroshima University

A 57-year-old man was admitted to our hospital because of bradykinesia. He was diagnosed with Parkinson disease (Hoehn and Yahr grade 2) and administered levodopa at the maximum dose of 800 mg. However, his condition did not improve. While his symptoms were responsive to levodopa therapy, the sensitivity to the drug was poor. Brain MRI revealed atrophy of the upper vermis and cerebral hemispheres, and brain SPECT revealed low perfusion in both parietal lobes. I123-metaiodobenzylguanidine scintigraphy showed a decrease in the heart/mediastinum ratio. Striatal dopamine transporter (DAT) density was evaluated using I123-FP-CIT. The patient showed moderately reduced DAT density, which suggested nigrostriatal dopaminergic damage. His mother was found to have pure cerebellar ataxia without parkinsonism, and her two siblings also had celebellar type of multiple system atrophy (MSA-C) and progressive supranuclear palsy, respectively. Genetic testing revealed that the patient, his mother and the uncle with MSA-C had spinocerebellar ataxia type 6 (SCA6). SCA6 presenting parkinsonism without ataxia is very rare and important for the pathomechanism of disease.
Full Text of this Article in Japanese PDF (573K)

(CLINICA NEUROL, 55: 243|247, 2015)
key words: spinocerebellar ataxia type 6 (SCA6), parkinsonism, levodopa response, DAT scan, nigrostriatum

(Received: 11-Apr-14)