Singer Carly Simon revealed that her Parkinson's disease diagnosis was initially obscured by symptoms commonly associated with arthritis, a condition she had undergone treatment for. This overlap in symptoms, particularly difficulties with walking and joint stiffness, can complicate early diagnosis, according to medical experts.
Simon shared that her health issues began with arthritis in her knees and hip, leading to joint replacements. She initially attributed her subsequent walking difficulties to the recovery process. However, the persistent mobility issues prompted further investigation, culminating in a Parkinson's diagnosis after an evaluation at the Mayo Clinic.
Arthritis, which affects approximately 60 million U.S. adults, impacts joints and connective tissues, causing pain, inflammation, and stiffness. Parkinson's disease, a progressive neurological disorder affecting about 1.1 million Americans, primarily impacts movement by affecting dopamine-producing nerve cells in the brain.
Despite their different underlying causes, the two conditions can present with shared symptoms. Dr. Guy Schwartz, a neurologist with Stony Brook Medicine, noted that difficulty with walking, joint or limb stiffness, reduced range of motion, balance problems, pain, and fatigue can be present in both. He explained that while arthritis pain is typically joint-driven, Parkinson's affects movement through neurological changes.
"Parkinson's disease can sometimes be misdiagnosed as arthritis, and vice versa," Schwartz stated. "The one main symptom that they share is difficulty with walking—some kind of impediment, limitation or disability."
Adding to the diagnostic complexity, both conditions are largely diagnosed based on clinical symptoms and physical examination rather than definitive tests. While tremors are often associated with Parkinson's, early signs can include stiffness and slowness of movement. In older adults, these symptoms may be easily mistaken for effects of arthritis or post-surgical recovery.
Parkinson's disease can also manifest with symptoms less common in arthritis, such as a resting tremor (often on one side), micrographia (smaller handwriting), reduced arm swing, a softer voice, a mask-like facial expression, bradykinesia (slowed movement), loss of smell, REM sleep behavior disorder, and constipation preceding movement symptoms.
Schwartz cautioned that tremors are not always present in Parkinson's patients, with about one-third not experiencing them, which can further challenge diagnosis. He also noted that arthritis and Parkinson's can coexist, as both become more prevalent with age, sometimes confounding the examination process.
Diagnosis of Parkinson's typically involves a detailed medical history, a neurological exam to identify symptoms like tremor, slowed movement, and gait changes, a physical exam, and assessment of the patient's response to Parkinson's medications. Additional tests may be used to rule out other conditions.
"It's not unusual for there to be misdiagnoses," Schwartz said. "Sometimes seeing a patient over time helps—eventually the disease declares itself, and then it's easier to make the diagnosis." Healthcare providers advise individuals experiencing persistent walking difficulties or unexplained stiffness to consult a physician for a potential neurological evaluation.