Frontostriatal Cognitive Staging in Parkinson's Disease

Abstract EN

Cognitive impairment and behavioural disorders are often encountered in subjects with Parkinson's disease (PD).

A simple PD-related frontostriatal cognitive dysfunction (PDFCD) staging is proposed.

Executive dysfunction and mental fatigue (stage I), depression/anxiety (stage IIa), apathy/pain (stage IIb), and dementia (stage III) reflect a sequential process of dopamine depletion occurring in different regions of the striatum (stages I and II) and the frontal cortex (stage III).

In addition to these nonmotor manifestations present in the unmedicated (OFF) state, the PDFCD model also predicts a number of complications related to dopaminergic treatment (ON state), from impulse control disorders (stages I and IIa) to hallucinations (stage IIb) and psychosis (stage III).

Although the model admittedly needs further refinements, it provides a framework for hypothesis testing and may help clinicians optimize therapeutic strategies.