Diagnosis and management of Parkinson's disease dementia.

Parkinson's disease (PD) has long been considered predominantly a motor disorder. However, its frequent association with dementia, which contributes significantly to the morbidity and mortality of the condition, is gaining increasing recognition. PD dementia (PDD) has a unique clinical profile and neuropathology, distinct from Alzheimer's disease (AD). Cholinergic deficits, a feature of both AD and PDD, underlie the rationale for cholinesterase inhibitor therapy in both conditions. In clinical practice, it is important that PDD should be recognised and appropriately treated. This review aims to outline the recently proposed clinical diagnostic criteria for PDD and to summarise the guidelines/recommendations published since 2006 on the use of cholinesterase inhibitors in the management of PDD. Although the cholinesterase inhibitor rivastigmine has recently been approved for the management of PDD, there remains a need for the development of novel therapies that can affect key mechanisms of the disease or prevent/delay patients with PD and mild cognitive impairment from progressing to PDD.