Autoimmune epilepsy is increasingly recognized in the spectrum of neurological disorders characterized by detection of neural autoantibodies in serum or spinal fluid and responsiveness to immunotherapy. The advent of more sensitive and specific serological detection methods is increasingly revealing previously underappreciated autoimmune epilepsies. Neural autoantibodies specific for intracellular and plasma membrane antigens aid the diagnosis of autoimmune epilepsy, but no single antibody is specific for this diagnosis.
Improving patient outcomes through autoimmune testing
Identifying epilepsy as autoimmune-mediated is crucial
because patients may benefit from immune suppression,
while traditional antiepileptic therapy may
not be effective.
In a Mayo Clinic study of 27 patients with suspected
autoimmune epilepsy treated with immunotherapy,
81% experienced clinical improvement and 67%
became seizure free.
When to consider testing
Consider autoimmune testing for patients presenting with new-onset epilepsy with incomplete seizure control, duration of less than two years, and one or more of the following:
- Subacute progression (maximal seizure frequency within three months)
- Multiple seizure types or faciobrachial dystonic seizures
- Antiepileptic drug resistance
- Psychiatric accompaniments (psychosis, hallucinations)
- Movement disorder (myoclonus, tremor, dyskinesia)
- Cognitive impairment/encephalopathy
- Autoimmune stigmata (e.g., physical signs or personal/ family history of diabetes, thyroid disorder, vitiligo, prematurely gray hair, myasthenia gravis, rheumatoid arthritis, systemic lupus erythematosus)
- History of cancer
- Smoking history (20+ pack years) or other cancer risk factors
- Inflammatory cerebrospinal fluid
- Neuroimages suggesting inflammation (limbic or extratemporal)
- Prior treatment with immune checkpoint inhibitors
- Antibody prevalence in epilepsy and encephalopathy (APE2) score is ≥41
Which test should I order?
A Test in Focus
Sean Pittock, M.D., gives an overview of the epilepsy autoimmune evaluations. He discusses when this testing should be ordered, how this testing compares to previous testing approaches, and what clinical action can be taken due to the results of this testing.