BACKGROUND: Parkinson disease (PD) is a progressive illness of undetermined cause with characteristic motor findings that include rest tremor, rigidity, bradykinesia, and postural disturbance. But cognitive impairment is common even in nondemented. In addition PD has been associated with an increased risk of developing dementia. OBJECTIVES: This review provides an analysis of the cognitive impairment associated with PD, about its aspects, risk factors, pathophysiology, and treatment. METHODS: The current review incorporates articles obtained through Medline. RESULTS: Non-demented and demented patients with Parkinson's disease are impaired in several cognitive tasks. These impairments may be attributed to dysfunction the circuits connecting the frontal cortical regions and the basal ganglia. Mild cognitive dysfunctions may progress to dementia in some patients. Some risk factors for the development of dementia were identified and aspects of pathophysiology were disclosed. CONCLUSION: Neuropsychological profile of PD, which predominantly reflects frontal dysfunction, may be attributed to disruption of the frontoestriatal circuitry. But the pathophysiology underlying dementia in PD is not completely understood. Cholinesterase inhibitors and memantine have a modest effect against cognitive symptoms. Early detection of risk factors for development of dementia may help to create preventive strategies.
Dementia; cognition; Parkinson's; disease
