LAUSR

While progressive dementia is essential for diagnosis of dementia with Lewy bodies (DLB), core features include parkinsonism, visual hallucinations, fluctuating levels of alertness, and REM sleep behavior disorder.1 Neuropathologic studies have shown that parkinsonism is the clinical feature most likely to distinguish patients with DLB from those with Alzheimer disease (AD).2,3 In one large prospective clinical study of 102 patients with DLB, parkinsonism was the second most prevalent clinical sign apparent at the time of data collection.4 In this large series of patients, DLB parkinsonism was responsive to levodopa, or another anti-Parkinson disease drug, in about 40% of the sample. The response was “moderate” in most patients, but they received no more than a mean levodopa equivalent daily dose (LEDD) of 303 mg. The risk of using higher doses of levodopa in patients with DLB is the exacerbation of underlying visual hallucinations, delusional ideas, or agitation.5 It is for this reason that we were pleased to read the study of Murata et al.6 in this issue of Neurology®, in which an old drug (zonisamide), in a randomized clinical trial, was a safe and effective adjunct to levodopa for the treatment of mild DLB parkinsonism.