By Michelle Jaffee
Among observers, questions long swirled about the extent to which Parkinson’s disease versus repeated hits to the head contributed to Muhammad Ali’s progressive tremor and cognitive impairment. Now, three neurologists who provided direct care to the boxing legend describe evidence in a JAMA Neurology viewpoint supporting a primary diagnosis of young-onset Parkinson’s disease over a form of dementia from repetitive head trauma.
In wishes expressed before his death at age 74 in June 2016, Ali declined an autopsy, so there was no post-mortem tissue diagnosis. But in the new article, published Oct. 24, physicians who treated Ali for more than 20 years at Emory University provide clear evidence to support a primary diagnosis of young-onset idiopathic Parkinson’s disease.
The team of Mahlon R. DeLong, M.D., a professor emeritus of neurology at the Emory University School of Medicine; Michael S. Okun, M.D., chair of neurology at the University of Florida and executive director of the Norman Fixel Institute for Neurological Diseases at UF Health; and Helen Mayberg, M.D., a professor of neurology and psychiatry at the Icahn School of Medicine at Mount Sinai, drew their conclusions from physical examinations and PET imaging from 1995 until Ali’s death.
“This is the first time that a group of physicians who continuously evaluated him over the years has spoken on the record,” Okun said. “He’s such an important part of history, not just American history but world history, and he’s been so iconic and so influential. I think it’s important for people to understand what the actual facts of the medical condition were from the doctors who examined him.”
In the new viewpoint piece, they write: “Here, we add this missing information to the archives of history. The main point of our report is that Muhammad Ali indeed had young-onset levodopa-responsive Parkinson disease with an emergence during the mid-phase of his boxing career.”
Among the details offered to support their conclusion:
- Ali was clearly responsive to levodopa, the most commonly prescribed medication to treat Parkinson’s symptoms, as documented in examinations in the early 1980s
- An FDG-PET scan in 1997 showed progressive bilateral striatal hyperactivity, a Parkinson’s-related pattern
- An F-DOPA PET scan in 1998 showed classical low striatal uptake, consistent with Parkinson’s and not traumatic brain injury
- Repeated observations confirmed that his prominent left-sided hand tremor, bradykinesia and rigidity all substantially improved when on medications, a key criterion for diagnosing idiopathic Parkinson’s
- Ali developed classic late-stage symptoms of idiopathic Parkinson’s, including stooped posture, shuffling steps, postural instability and falling
- Serial neuropsychological testing showed progressive frontal and memory impairments consistent with classical Parkinson’s
Ali’s case, the physicians wrote, “reinforces the dangers of the press, public and health care professionals in speculating on medical diagnoses in the absence of an in-person examination.”
“A 34-year chronic progressive presentation with asymmetric levodopa-responsive resting tremor, accompanied by other classical features, provides strong evidence for a diagnosis of idiopathic Parkinson’s disease,” they wrote. “In contrast, post-traumatic tremor is commonly transitory and manifests as a postural and/or kinetic tremor. In addition, post-traumatic tremor is not accompanied by progressive cogwheel rigidity and bradykinesia, both observed in Ali.”
Furthermore, they added: “Head trauma is a known risk factor for the later onset of idiopathic Parkinson’s disease; however, a causative association in the Ali case cannot be determined.”