Patients with typical parkinsonism (n=6) were older, mean age 56.5±10.9, demonstrated more mild symptoms, median UPDRS part III 18.0(7.0), and were responsive to levodopa (n=4). Three of the six patients had associated cognitive decline interpreted as underlying Alzheimer’s pathology. Patients with suspected DSRD (n=4) were younger, mean age 24.0±7.8, demonstrated more severe symptoms, median UPDRS part III 34.0(4.5), and were not levodopa-responsive (n=2). Four patients exhibited predominant gait freezing with minimal to no other parkinsonism and no evidence of levodopa trial.
Three of four patients with suspected DRSD were treated with intravenous immunoglobulin ranging from 1.5 to 2 g/kg and achieved resolution of parkinsonism. One patient had improvement with daily lorazepam. There were no abnormalities on DaTscan (n=2). One patient demonstrated significant mineralization in the basal ganglia on CT. Cerebrospinal fluid (CSF) was non-inflammatory (n=3). Serum showed elevated thyroid peroxidase antibodies in one patient. All autoimmune panels in serum (n=3) and CSF (n=3) were non-contributory.