Many new studies of
cognitive impairment and
dementia in
Parkinson's disease have been published during 2004.
Cognitive impairment has been demonstrated even during the first 1-2 years after onset of disease. Whereas executive and attentional impairment is typical, learning deficits occur early in some patients. Both functional and structural imaging suggest that in addition to fronto-subcortical deficits, temporal and parietal changes occur early as well. In the first large placebo-controlled trial, the
cholinesterase inhibitor rivastigmine improved cognition, daily functioning and psychiatric symptoms without worsening of
parkinsonism. The frequency and characteristics of depression, anxiety and
hallucinations have been explored in several studies. Unfortunately, there is still little scientific evidence available to guide the treatment of these important aspects of
Parkinson's disease, and adequately designed clinical trials are needed. Although subthalamic stimulation, in addition to improvement of movement, is frequently associated with some affective and cognitive improvement, permanent and significant worsening may occur in some. Future studies should aim at identifying at-risk patients, as well as identifying the optimal pharmacological and stimulation treatments for individual patients.
SUMMARY: