While an estimated 1.8% of US adults have epilepsy, the prevalence is more than 22% among people with intellectual disabilities.1,2 Managing epilepsy in this patient population can be particularly challenging for a variety of reasons.
“This group will have a higher likelihood of communication problems and other issues that make it more difficult to be treated than patients with a higher IQ, and they tend to have more behavioral issues,” Scott Hirsch, MD, a neuropsychiatrist at NYU Langone Comprehensive Epilepsy Center and assistant professor in the departments of neurology, child and adolesecent psychiatry, and psychiatry at NYU Langone Medical Center, told Neurology Advisor. “You’re also likely to see more of every kind of mental illness in this group, including autism, ADHD, schizophrenia, and depression,” he said.
Generally, around 70% of patients with epilepsy respond to treatment and have good outcomes, while 30 to 40% are treatment resistant, according to Rohit Shankar, MRCPsych, a neuropsychiatrist and researcher with the Cornwall Partnership NHS Foundation Trust in the United Kingdom. Among patients with comorbid epilepsy and intellectual disabilities, “those who do not respond to treatment tend to have worse outcomes,” he told Neurology Advisor.
Adding to the clinical difficulty is the lack of guidelines pertaining to best practices for this group. In a review conducted by Dr Shankar and colleagues published in the European Journal of Neurology, the researchers found a dearth of reliable research to inform safe prescribing practices of antiepileptic drugs (AED) for people with intellectual disabilities.3
“It is quite surprising that no one has tried to understand this population and its diverse needs,” he said. Such diversity is an often overlooked point, he notes: “Patients in this population have been treated like a homogeneous subset,” when, in fact, there is a wide variety of presentation in this group.
On one end of the spectrum are patients with mild disability who are able to manage activities of daily living with little support. Approximately 10% to 12% of this group has epilepsy, and treatment is mainly focused on areas like compliance and risky behaviors, Dr Shankar explained. At the other extreme are patients with profound disability, whose needs are much more complex. They are more likely to have additional genetic conditions and structural brain damage, and they require constant care. Up to 50% of this group has epilepsy, and their treatment is more focused on factors such as the impact of medications, recognition of side effects, and informed consent. There may be an added layer of complexity in patients with epilepsy who also have a co-occurring intellectual disability and mental illness. “For instance, you may try to give medication to a patient with schizophrenia and intellectual disability, and they might think you’re trying to hurt them,” said Dr Hirsch.