Complaints about impairments in executive functions in Parkinson's disease: the association with neuropsychological assessment

Impairments in executive functions are frequently reported in Parkinson's disease (PD). However, little is known about patients' experience regarding these impairments. This knowledge is crucial because if patients do not experience their cognitive impairments they do not report them to their attending neurologist. Consequently, patients might not get appropriate treatment. This study investigated if patients with a mild to moderate PD experience impairments in executive functions in daily life and whether these correspond with impairments as measured in neuropsychological assessments. Forty-three PD patients and 25 healthy participants were included. Groups did not differ in age, sex and education. All participants and their closest relatives completed a standardized questionnaire measuring executive functions in daily life. Furthermore, all participants were assessed with a test battery measuring executive functions. PD patients reported significantly more problems with executive functions in daily life than healthy participants. Furthermore, co-morbid depression had a negative impact on the number of problems with executive functions in daily life as reported by PD patients. The experienced daily life problems in executive functions were not associated with the patients' performance on objective cognitive measures. In conclusion, PD patients were aware of problems with executive functions in daily life and reported considerably more problems than healthy controls. These problems were however not reflected by neuropsychological tests and may indicate a lack of ecological validity of neuropsychological assessment.