Dystonia in multiple system atrophy.
OBJECTIVE
To delineate the frequency and nature of dystonia in multiple system atrophy (MSA).


METHODS
A cohort of 24 patients with clinically probable MSA over the past 10 years were prospectively followed up. Motor features were either dominated by parkinsonism (MSA-P subtype, n=18) or cerebellar ataxia (MSA-C, n=6). Classification of dystonic features and their changes with time was based on clinical observation during 6-12 monthly follow up visits. Parkinsonian features and complications of drug therapy were assessed. Most patients (22/24) died during the observation period. Neuropathological examination was confirmatory in all of the five necropsied patients.


RESULTS
At first neurological visit dystonia was present in 11 (46%) patients all of whom had been levodopa naive at this time point. Six patients (25%) exhibited cervical dystonia (antecollis) (MSA-P n=4, MSA-C n=2), five patients (21%) showed unilateral limb dystonia (MSA-P n=4; MSA-C n=1). A definite initial response to levodopa treatment was seen in 15/18 patients with MSA-P, but in none of the six patients with MSA-C. A subgroup of 12 patients with MSA-P developed levodopa induced dyskinesias 2.3 years (range 0.5-4) after initiation of levodopa therapy. Most patients had peak dose craniocervical dystonia; however, some patients experienced limb or generalised dystonia. Isolated peak dose limb chorea occurred in only one patient.


CONCLUSIONS
The prospective clinical study suggests that dystonia is common in untreated MSA-P. This finding may reflect younger age at disease onset and putaminal pathology in MSA-P. Levodopa induced dyskinesias were almost exclusively dystonic affecting predominantly craniocervical musculature. Future studies are required to elucidate the underlying pathophysiology of dystonia in MSA.
Boesch
S M
SM
Department of Neurology, University Hospital, Innsbruck, Austria.
Wenning
G K
GK
Ransmayr
G
G
Poewe
W
W
D000368:Aged; D001921:Brain / Q000187:drug effects / Q000473:pathology; D004409:Dyskinesia, Drug-Induced / Q000175:diagnosis / Q000473:pathology; D004421:Dystonia / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology; D005260:Female; D006801:Humans; D007980:Levodopa / Q000009:adverse effects / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology; D009460:Neurologic Examination; D010302:Parkinson Disease, Secondary / Q000175:diagnosis / Q000188:drug therapy / Q000473:pathology
D007980:Levodopa