Kenny Lin, MD, MPH
Posted on July 10, 2023
A recent news story in The Philadelphia Inquirer profiled a Black woman who visited her primary care physician for upper body pain, stiffness, and an unusual gait and was surprised when she was ultimately diagnosed with Parkinson disease. Known by many as an “old White man’s disease,” Parkinson disease affects around 1 million Americans but historically has had low visibility in the Black community, with rare exceptions such as the late boxer Muhammad Ali, who lived with it for 34 years before his death.
Although some studies have suggested that Parkinson disease occurs less often in Black patients than in White patients, a 2020 review found mixed evidence that incidence and prevalence differ significantly by race and pointed to disparities in accessing health care at similar degrees of symptomatology as possible explanations for discordant study findings. A study of 74 patients with newly diagnosed Parkinson disease at a Veterans Affairs medical center concluded that Black patients were less likely than White patients to self-report disability, possibly leading to delays in diagnosis.
According to a 2020 article in American Family Physician, Parkinson disease most commonly presents with “a unilateral resting tremor, often localized to the distal muscles of the hand, causing a pill-rolling motion.” Other key features include cogwheel rigidity and bradykinesia, such as shuffling steps and a freezing gait. Nonmotor symptoms “include rapid eye movement sleep disorder, depression, constipation, fatigue, and olfactory dysfunction” and may precede motor symptoms in many cases. Postural instability and falls occur later in the course of illness. In cases of diagnostic uncertainty, a dopamine transport single-photon emission computed tomography scan (DaTscan) may be used to distinguish Parkinson disease from atypical essential tremor and drug-induced Parkinson-like syndromes.
Recommended therapies for motor symptoms (summarized in a Table and treatment algorithm) include carbidopa/levodopa for significant symptoms, monoamine oxidase-B inhibitors or non-ergot dopamine agonists for milder symptoms, and anticholinergic agents and amantadine for patients younger than 65 years with tremors only. Another Table summarizes pharmacologic management of common nonmotor symptoms. Unfortunately, no therapies have been shown to slow disease progression. On average, patients with Parkinson disease progress from impairment to loss of independence between three and seven years after diagnosis. In patients with Parkinson disease, 40% develop dementia, 20% to 40% develop psychosis, and some eventually have swallowing impairments, aspiration pneumonia, and weight loss due to loss of appetite and difficulty eating.
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