Vascular parkinsonism: clinical correlates predicting motor improvement after lumbar puncture

Vascular parkinsonism (VP) is a poorly defined entity which has clinical, and perhaps pathological, overlap with other diagnoses. Although classical VP involves lesions of the basal ganglia, the majority of cases actually show diffuse subcortical white matter changes (SCWMC) on imaging. The exact pathologies of these white matter changes are debated and likely heterogeneous, but are generally thought to represent areas of chronic or recurrent partial ischemia. Cerebrospinal fluid (CSF) drainage is the treatment for NPH and has been reported to improve symptoms in some patients with idiopathic NPH and associated SCWMC. To determine whether historical, clinical, or radiographic factors predict improvement in VP patients after CSF drainage, we removed 35-40 ml of CSF via lumbar punctures (LP) from 40 patients and compared responders with nonresponders for a variety of demographics, clinical features, and blindly interpreted magnetic resonance images (MRI). Fifteen patients (37.5%) reported "significant and irrefutable" gait improvement after LP. Twelve (30.0%) reported no effect and 13 (32.5%) reported mild or very transient improvement. Timed gait in a subset of patients improved (P < 0.05) immediately after LP. Clinically, improvement after CSF removal was predicted by any positive response to levodopa (P < 0.001), the lack of vertical gaze palsies (P < 0.05), the lack of a pure freezing gait (P < 0.05), and the lack of hypotensive episodes (P < 0.05). Blinded MRI interpretation did not find features which clearly predicted response. Some patients diagnosed with VP improved after LP. Clinically, these patients tended to resemble idiopathic PD, whereas nonresponders more closely resembled progressive supranuclear palsy (PSP). These results warrant further investigation and also raise the possibility of testing CSF drainage in patients with idiopathic PD complicated by SCWMC.