Unexpected Cognitive Deteriorations in Epilepsy

By: Dr. Lance Fogan

Photo Credit: www.depositphotos.com

Lance Fogan, M.D. is Clinical Professor of Neurology at the David Geffen School of Medicine at UCLA. His hard-hitting emotional family medical drama, “DINGS, is told from a mother’s point of view. “DINGS” is his first novel. Aside from acclamation on internet bookstore sites, U.S. Report of Books, and the Hollywood Book Review, DINGS has been advertised in recent New York Times Book Reviews, the Los Angeles Times Calendar section and Publishers Weekly. DINGS teaches epilepsy and is now available in eBook, audiobook, soft and hard cover editions.

Several blogs at LanceFogan.com (https://lancefogan.blogspot.com/2022/08/blog-145-epilepsy-patient-passes.html. https://lancefogan.blogspot.com/2020/08/blog-121-if-your-seizures-arent.html) have highlighted the effectiveness of epileptic surgery. The foci of abnormal brain cell neurons in focal epilepsy poorly responsive to anti-epilepsy drugs (AEDs) are removed. If surgically removing these cells is considered safe and the surgery would not affect speech, movement, sensory, memory and visual abilities, this treatment should be strongly considered. Surgical intervention commonly is the best effective, and commonly curative treatment.

Long-term studies have shown that after successful epilepsy surgery in the great majority of patients their brain performance recovers. However, recent studies at the University of Bonn, Germany1  found after the successful surgery that in rare cases neuropsychological performance declines months later. The study found that the surgical tissue removed indicates a rare secondary independent, neurodegenerative disease beyond any direct surgical effects. Evidently, a small subset of patients experiences a significant cognitive decline following surgery for temporal lobe epilepsy (TLE), independent of and in addition to the eventual cognitive sequelae of the surgical treatment. Who are these patients, and what are the underlying causes?

Eight percent of all 355 patients in the study with at least 2 neuropsychological assessments after epilepsy surgery showed a relevant cognitive decline from one postoperative follow-up examination to a subsequent evaluation. The most frequently affected cognitive domain by far was verbal memory (96%), followed by figural memory (33%) and executive functions (25%). Repeated cognitive declines in the time after surgery were observed in 5 of the 24 patients (21%).

The findings indicate that patients who unexpectedly displayed unfavorable cognitive development beyond any direct surgical effects show rare and very particular pathogenetic causes or parallel, presumably independent, neurodegenerative alterations. In those affected, was the removed tissue damaged by secondary disease at the time of surgery – either through inflammation or incipient Alzheimer’s dementia-like? The researchers considered with these pre-existing conditions; the body’s defenses are particularly active. It’s possible that the trauma of the surgical procedure further stimulates the immune system in the brain to attack healthy brain tissue.” Further studies are indicated.


  1. Reimers A, Helmstaedter C, Elger C, et al., Neuropathological Insights into Unexpected Cognitive Decline in Epilepsy .Ann Neurol. Nov 2022

Read More