Topographic and temporal patterns of dyskinesia in multiple system atrophy with predominant parkinsonism

Background

Although dyskinesia is well recognized in Parkinson's disease, it is generally under acknowledged in multiple system atrophy (MSA). Reported cases of dyskinesia primarily manifest in patients with MSA with predominant parkinsonism (MSA-P), and characteristically present as orofacial dystonia. However, we have observed other manifestations of dyskinesia in our clinical practice. The current report aims to present the specific manifestations of dyskinesia in MSA-P, with videos.

Methods

We enrolled six patients with MSA-P with dyskinesia from Xuanwu Hospital. Of these, four had clinically established MSA-P and two had clinically probable MSA-P according to the 2022 Movement Disorder Society criteria for MSA diagnosis. All six patients underwent an acute levodopa challenge test, and videos were recorded during the process.

Results

Dyskinesia had a unilateral distribution in four patients. Three patients presented with peak-dose orofacial dystonia; of these, two were associated with blepharospasm and two were associated with limb dystonia. In addition, we observed that one patient had peak-dose distal lower limb dystonia with upper limb chorea, one patient had wearing-off dystonia of the eyelids, and one patient had diphasic generalized chorea mimicking that of Parkinson's disease.

Conclusions

In addition to orofacial dystonia, the topographic patterns of dyskinesia in MSA-P can manifest as limb dystonia, blepharospasm, and generalized chorea. Moreover, the temporal patterns of dyskinesia in MSA-P can be peak-dose, wearing-off, or diphasic.