The prevalence of neurodegenerative diseases such as Parkinson's disease (PD) increases with age. In an aging population, an understanding of the management of late complications of PD is becoming ever more important. Drug treatment for Parkinson's disease is largely symptomatic and relies primarily on levodopa (L-dopa) and adjuvant therapies including dopamine agonists and catechol-O-methyltransferase (COMT) inhibitors. Rehabilitation and allied health input also constitutes a core part of successful management. Most subjects who are symptomatic for more than 5 years are prone to late complications of PD. Some of these are related to the treatment, such as motor fluctuations, including the "on-off" phenomenon and levodopa-related peak dose dyskinesia. Others, such as postural hypotension, falls, psychosis, and dementia, although well-recognized problems in the elderly, often require different treatment strategies if occurring in the context of PD. The practical evidence-based management of motor and non-motor complications in late PD is discussed.

Chan DKY, Cordato DJ, O'Rourke F. Management for motor and non-motor complications in late Parkinson's disease. Geriatrics. 2008;63(5):22-27.

Key words: Parkinson's disease, motor complications, non-motor complications

Dr Chan is Professor, University of New South Wales; and Director and Geriatrician, Department of Aged Care & Rehabilitation, Bankstown-Lidcombe Hospital, Bankstown, New South Wales, Australia.

Dr Cordato is Neurologist, Department of Neurophysiology, Liverpool Hospital, Liverpool, New South Wales, Australia.

Dr O'Rourke is Staff Specialist, Department of Aged Care & Rehabilitation, Bankstown-Lidcombe Hospital.

Disclosures: The authors disclose that they do not have any financial relationships with any manufacturer in this area of medicine.

Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease, and it increases in prevalence with increasing age.¹ As the population of many developed countries is aging rapidly, the number of people worldwide with PD is also expected to increase rapidly over the next few decades.

Accumulating evidence indicates that PD is not limited to the nigrostriatal system and may actually originate from the dorsal motor nucleus of the glossopharyngeal and vagal nerves and anterior olfactory nucleus. Thereafter, the disease spreads from the brain stem in an ascending course. Cortical involvement ensues, starting with the anteromedial temporal mesocortex and later involving the neocortex.² Other supporting evidence includes neuropathologic changes that not only affect dopaminergic neurons but also a significant number of other nerve cells. These include glutaminergic, cholinergic, tryptaminergic, GABAergic, noradrenergic, and adrenergic neurons that also show grievous cytoskeletal damages.³ This body of evidence explains the non-motor complications of PD such as depression (frontal lobe mediated by serotonin), memory loss (temporo-hippocampal mediated by acetylcholine), dysexecutive function (frontal lobe), dysautonomia, dysphagia, and sleep problems (brain stem).

No curative treatment now exists for PD. Although levodopa (L-dopa) is the cornerstone of symptomatic treatment for motor symptoms, steady response only lasts for about 5 to 7 years. After that, response to treatment is suboptimal resulting in late complications such as motor fluctuations and dyskinesia. In addition, response to treatment is either poor or lacking for non-motor complications. Most of the current available evidence seems to be derived from studies based on younger populations.

How best to use the available information and apply it to older patients is particularly challenging. Of relevance is the lack of high-level evidence guiding clinicians in the management of many non-motor complications. This article reviews the current evidence for managing late complications in PD, both motor and non-motor, with special attention to older patients.