Frontostriatal cognitive staging in Parkinson's disease

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. © 2012 ral de la fuente-fernndez.