Predictors of Cognitive Decline in the Early Stages of Parkinson's Disease: A Brief Cognitive Assessment Longitudinal Study

Abstract EN

Our objectives were to perform a longitudinal assessment of mental status in early stage Parkinson’s disease (PD) patients, with brief neuropsychological tests, in order to find predictive factors for cognitive decline.

Sixty-one, early stage, and nondemented patients were assessed twice, over a 2-year interval, with a global cognitive test (mini-mental state examination (MMSE)) and a frontal function test (frontal assessment battery (FAB)) and motor function scales.

Dementia and hallucinations were diagnosed according to the DSM-IV criteria.

Cognitive function scores did not decrease significantly, except for FAB lexical fluency score.

Four patients presented with dementia at followup.

The MMSE score below cut-off, worse gait dysfunction, the nontremor motor subtype, and hallucinations were significantly related to dementia.

Rigidity and speech dysfunction were related to dementia and a decrease in FAB scores.

We can conclude that decline in the MMSE and FAB scores is small and heterogeneous in the early stages of PD.

Scores below cut-off in the MMSE could be helpful to predict dementia.

Nontremor motor deficits could be predictive factors for frontal cognitive decline and dementia.