Dementia is common in patients with Parkinson's disease (PDD). The etiology of PDD is still unclear, but exciting advances have been made in discovering pathogenetic components in Parkinson's disease (PD), implicating the role of genetic factors. It is, however, still controversial whether genetic factors also contribute to the development of dementia in PD. Thus, we investigated the association between development of dementia and a positive family history of PD or dementia in a community-based study of PD in Rogaland County, Norway (n = 219). The patients were followed prospectively with neurological and neuropsychological assessments. Dementia was more common in patients with a strong family association of PD (first-degree relatives > second-degree relatives > no family history; P < 0.05). However, time to dementia did not differ between the two groups. No associations between dementia in PD and familial occurrence of dementia could be shown. Further studies with larger samples are needed to explore a possible relationship between a family history of PD and development of dementia in PD and its potential pathogenetic mechanisms.
Copyright 2006 Movement Disorder Society.