Older adults diagnosed with autism are at significantly higher risk of developing movement disorders related to Parkinson’s disease than the general population, according to a large new study published in the journal Autism.
Researchers analyzed Medicare and Medicaid claims data covering nearly 57 million Americans ages 45 and older between 2017 and 2019.
People on the autism spectrum, as well as those with intellectual disabilities, have been diagnosed with Parkinsonism at much higher rates than those without autism.
Parkinsonism refers to a range of neurological disorders characterized by certain movement symptoms, including tremors, muscle rigidity, difficulty with balance and slowing of voluntary movements, according to the Parkinson’s Foundation.
While previous research suggested an overlap between autism and motor decline later in life, it was unclear whether these problems stem from the illness or from antipsychotic medications, which are widely known to trigger Parkinson’s-like symptoms as a side effect.
To determine whether medications explained the link, the researchers excluded people taking antipsychotics from the analysis. They did, however, find higher rates of Parkinson’s-related diagnoses in neurodivergent populations.
In the general population control group, the prevalence of Parkinsonism was approximately 1.57%. The prevalence increased to 3.83% among adults with autism alone, 4.32% among those with intellectual disability alone, and 4.86% among those diagnosed with both autism and intellectual disability.
“A critically important new contribution from this study is the increased incidence rates of Parkinsonism among people with autism in middle and late adulthood, suggesting that these cases are not simply a byproduct of persistent motor problems,” said Greg Wallace, lead author and professor in the Department of Speech, Language, and Hearing Sciences at George Washington University in Washington, DC, in a press release.
The study represents the first time scientists have tracked the incidence rate, or risk of new cases emerging over time, among older autistic people.
“It is therefore important for clinicians to establish clear baselines of motor skills and challenges in adulthood that can be tracked over time,” Wallace added.
Dr. Lee Murray, a neurologist based in Jackson, Tennessee, said this study clarifies previous research suggesting that autistic patients are at higher risk of developing Parkinson’s disease.
“This study takes into account the use of antipsychotic medications that can cause a Parkinsonian appearance (resting tremor, stiffness, shuffling gait, hunched posture, softened voice), which is a different pathology from stereotypical or idiopathic Parkinson’s disease,” Murray, who was not involved in the study, told Fox News Digital.
“This study showed that patients with autism associated with intellectual disability appear to have the greatest association with concomitant Parkinson’s disease.”
The neurologist cautioned that autism encompasses a wide range of symptoms and severity, so the findings do not mean that people with milder cases are at significantly higher risk of Parkinson’s disease.
“It’s certainly an interesting correlation, although it doesn’t imply that a person with autism will definitely develop Parkinson’s disease,” Murray added.
“From a clinical perspective, it is helpful to review medications with the autistic patient’s doctors and, if possible, try to avoid medications that may cause the onset of Parkinson’s disease.”
Despite the breadth of the data, the authors noted several key limitations related to the use of insurance records.
The investigation relied on billing and diagnosis codes submitted through Medicare and Medicaid, which may contain errors or reflect differences in how clinics and medical providers diagnose conditions.
Reliance on claims data also means researchers cannot assess the severity of individual motor symptoms or examine the role of lifestyle factors, genetics and family history, they noted.
Additionally, the data only considered adults enrolled in public insurance programs, potentially leaving out older adults who rely strictly on private health insurance.
Because people on the autism spectrum may already have problems with coordination, repetitive behaviors or problems with executive functioning, experts say early indicators of Parkinson’s disease may be missed or erroneous, which can delay critical care.
“Autistic patients can have atypical movements that can be misdiagnosed as Parkinson’s if the examiner is not accustomed to diagnosing them,” Murray confirmed.
The researchers highlighted the need for doctors, long-term care facilities and family caregivers to closely monitor older autistic patients for motor decline so that interventions can begin as soon as possible.
Gn Health
