Commentary on "Parkinson disease: research update and clinical management".

In 1817, James Parkinson published the essay ‘‘Shaking Palsy,’’ in which he described patients with ‘‘involuntary tremulous motion’’ and ‘‘a propensity to bend the trunk forward and to pass from a walking to a running pace. ’’ The disorder was further characterized by Jean-Martin Charcot in 1872, who first referred to the disorder as Parkinson disease. Almost 100 years would pass before patients would be offered an effective treatment. The discovery in the late 1950s of dopamine as an important neurotransmitter in the brain was a landmark accomplishment in understanding Parkinson disease. Clinical trials of levodopa followed soon after in the 1960s. Levodopa was to become the most effective agent for the treatment of Parkinson disease. Despite these advances, the ultimate cause of Parkinson disease remains as unknown now as it was when first described by James Parkinson. As noted by Fritsch et al in this issue of the Southern Medical Journal, theories regarding the pathogenesis of Parkinson disease include viral pathogens, environmental factors, and genetic susceptibility. Parkinson disease is the second most common neurodegenerative disease, behind Alzheimer disease. Like Alzheimer disease, the prevalence of Parkinson disease increases with age, affecting approximately 1% of the population older than 60 years. Estimates indicate that by the middle of the current century, 80 million people will be older than 65 years and approximately 20% will be older than 85 years. The large increase in older individuals coupled with the increasing life expectancy of older Americans will mean that doctors can expect to see more patients with the diseases that are common in older age. This will certainly be the case with diseases such as Alzheimer and Parkinson disease and primary care physicians can expect to see more patients with these diseases in the coming years. The Institute of Medicine report Retooling for an Aging America: Building the Health Care Workforce notes that the number of physicians trained in the care of older patients is inadequate and is not able to meet the demands of an everincreasing aging population. A number of solutions have been suggested to address this disparity, such as increasing the training of geriatric specialists and improving financial incentives for caring for older patients. With this in mind, it becomes apparent that primary care physicians will play an increasing role in the care of older patients. It will be incumbent, therefore, upon primary care clinicians to familiarize themselves with the important diseases of an aging population such as Alzheimer and Parkinson. Thus, updates such as the one provided by Fritsch and colleagues in this issue of the Southern Medical Journal are timely in that we are provided with a concise review of Parkinson disease, a common movement disorder that many primary care physicians will see increasingly often in their practices. The update also is timely in light of evidence that a significant knowledge gap about established guidelines for Parkinson disease exists among primary care physicians. In a 2007 survey, it was found that fewer than 50% of primary care physicians were compliant with established guidelines for Parkinson disease. Although many of the classical features of Parkinson disease are well known to primary care clinicians and specialists alike, some features of this disease in older patients can be challenging to discern. For example, as people age their physiologic reserves decline and their ability to tolerate stressful circumstances, whether from intercurrent illnesses or medications, is greatly depleted. As comorbidities increase with aging, it becomes increasingly difficult to differentiate certain age-related changes from those caused by Parkinson disease. For example, arthritis impairs mobility and dexterity, which can obscure some of the features of Parkinson disease. As noted by Fritsch et al, other nonmotor features of Parkinson disease often are seen with aging, such as depression, constipation, bladder symptoms, sleep disturbances, and autonomic nervous system failure. Older individuals often exhibit polypharmacy, with approximately 20% of patients older than 65 years taking Q10 Invited Commentary