Chou_2013_Neurology_81_1278

Cognitive impairment is common in patients with Parkinson disease (PD) without dementia, and may be present even at diagnosis.1,2 Although a wide range of cognitive domains may be affected in patients with PD without dementia, early cognitive deficits usually occur in the domains of attention and executive function (planning, sequencing, processing speed, and working memory).3 While cholinesterase inhibitors improve cognition in PD dementia, only a limited number of trials have investigated pharmacologic agents for mild cognitive impairment in PD, and none has been proven to be effective.1 There is limited evidence for nonpharmacologic cognitive interventions in PD; existing studies have focused on physical exercise1 or enhancing sensory-perceptual function, thereby improving stimulus quality to enable better cognitive processing.4,5.