Cognitive impairment in Parkinson's disease

Parkinsons disease (PD), a neurodegenerative disorder characterized by motor impairments, including bradykinesia, cogwheel rigidity, and resting tremor, also impairs intellectual functioning. Almost all patients with PD suffer from selective cognitive impairments, including difficulties with attention, concentration, problem solving, set-shifting, and memory, which are thought to reflect dysfunction of cortical circuits subserving frontal brain regions. These impairments are most frequently reported by patients in terms of the disabilities they cause, such as difficulties in paying attention at work; problems handling more than one project at a time; inability to sequence, plan, and organize tasks at work and home; and problems completing tasks that have been started. These disabilities present serious complications for patients in the management of their everyday lives, particularly with regard to occupational functioning. In addition, perhaps one-quarter of PD patients will go on to develop dementia, initially developing significant memory problems. At the present time, treatment of cognitive dysfunction relies primarily on patient and family education, behavioral interventions, and the use of cholinesterase inhibitors.