Cerebral blood flow changes in Parkinson?s disease associated with dementia

Abstract

Dementia is one of the main non-motor symptoms of Parkin- son's disease (PD) and it is diagnosed in about 30% of cases. Its aetiology remains unclear and contributing factors are con- troversial. Dementia may be more common in old patients with severe motor symptoms and mild cognitive impairment. Clini- co-pathological studies show the association between demen- tia in PD and the age-related group of dementias, such as AD and VaD. A valuable aid in the assessment of dementia in PD is cerebral blood flow (CBF) brain SPECT scanning. It shows three differ- ent patterns of rCBF reduction, including frontal lobe hypoper- fusion, iuAlzheimer-likel type of hypoperfusion and multiple, vas- cular defects. The heterogeneity of rCBF reduction may reflect the multifactorial pathophysiology of dementia in PD. It may result from concomitant AD pathology, cerebrovascular disease, destruction of nigro-striato-frontal projection or may be a dis- tinct disease of different aetiology.