Dopa-responsive parkinsonism phenotype of spinocerebellar ataxia type 2

• Published in: Movement disorders Vol. 17; no. 5; pp. 1046 - 1051
• Main Authors: Lu, Chin-Song, Wu Chou, Yah-Huei, Yen, Tzu-Chen, Tsai, Chon-Haw, Chen, Rou-Shayn, Chang, Hsiu-Chen
• Format: Journal Article
• Language: English
• Published: New York Wiley Subscription Services, Inc., A Wiley Company 01.09.2002; Wiley
• Subjects: [99mTc]TRODAT-1 SPECT; Aged; ataxin-2 gene; Atrophy - pathology; Biological and medical sciences; Cerebellum - pathology; Corpus Striatum - pathology; Corpus Striatum - physiopathology; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Dopamine Agonists - therapeutic use; Genotype; Humans; Levodopa - therapeutic use; Magnetic Resonance Imaging; Male; Medical sciences; Middle Aged; Neurology; Organotechnetium Compounds; Parkinsonian Disorders - drug therapy; Parkinsonian Disorders - genetics; Parkinsonian Disorders - pathology; parkinsonism; Pedigree; Pons - pathology; Radiopharmaceuticals; spinocerebellar ataxia type 2; Spinocerebellar Ataxias - genetics; Spinocerebellar Ataxias - pathology; Spinocerebellar Ataxias - physiopathology; Substantia Nigra - pathology; Substantia Nigra - physiopathology; Tomography, Emission-Computed, Single-Photon; Tropanes; Tropical medicine; Human; Nervous system diseases; Radiodiagnosis; Emission; Parkinson disease; Exploration; Antiparkinson agent; Photon; Cerebral disorder; Genetic disease; Case study; Spinocerebellar heredodegeneration; Phenotype; Central nervous system disease; Tomography; Degenerative disease; Levodopa; Spinal cord disease; Extrapyramidal syndrome
• ISSN: 0885-3185; 1531-8257
• DOI: 10.1002/mds.10243

We report on 2 brothers, Patients 1 and 2, who presented with a similar clinical syndrome consisting of resting tumor, bradykinesia, rigidity, and dysarthria at the ages of 40 and 43 years, respectively. An excellent response to levodopa therapy was observed throughout the disease course. No gait or limb ataxia, slow saccades, or decreased tendon reflexes were detected, but unsteadiness of gait with propulsion developed recently in Patient 1 approximately 25 years after disease onset. Magnetic resonance imaging demonstrated mild atrophy of the pons and cerebellum in Patient 1 and cerebellar atrophy in Patient 2. Expanded CAG repeats, numbering 36, in one allele of the ataxin‐2 gene were identified in Patient 1 only; his brother was not available for this investigation. With [99mTc]TRODAT‐1 single photon emission computed tomography of the brain, a significant bilateral and asymmetrical reduction of striatal dopamine transporters was found in Patient 1 compared to healthy controls. This bilateral reduction of striatal dopamine transporters resembled that observed in a set of controls with Parkinson's disease who had asymmetrical impairment. These results suggest that patients with familial parkinsonism who present with typical Parkinson's disease should be screened for the genetic defect of spinocerebellar ataxia type 2. The presynaptic impairment of nigrostriatal function is very likely to be the reason for levodopa responsiveness. © 2002 Movement Disorder Society