In the case of severe epilepsy, only surgery can often help – usually with great success. While brain performance can recover over the long term after a successful operation, in rare cases there may be an unexpected drop in cognitive performance. Researchers at the University of Bonn have now been able to show which patients are at particularly high risk. Their results have been published in the journal Annals of Neurology. They could help to identify those affected for whom surgery should be avoided. Instead, new treatment perspectives arise for those affected.
Epilepsy cannot always be controlled with medication. In these cases, those affected should have it clarified whether an operation is possible. During the procedure, surgeons remove the damaged brain tissue that is the source of the seizures. Patients can often be cured completely as a result.
“The operation has revolutionized the treatment of severe epilepsy,” explains Dr. Juri-Alexander Witt, private lecturer in the clinic for epileptology at the University Hospital Bonn. “However, there is always a risk of cognitive impairment during epilepsy surgery. However, long-term studies have shown that brain performance can recover over the long term after a successful operation.”
Unexpected drops in performance months after the procedure
However, in a small proportion of those affected, unexpected drops in performance only occur months or years after the operation. “We wanted to know why that is,” says Annika Reimers, a doctoral student at the Institute of Neuropathology in Prof. Dr. Albert Becker.
The researchers were helped by the long experience that the University Hospital Bonn has in epilepsy surgery: They were able to fall back on brain tissue samples, some of which had been taken decades ago. “We analyzed a total of 24 samples from men and women who had been found to have serious cognitive impairments months or even years after the operation,” explains Reimers.
The scientists came across an anomaly: the tissue removed from those affected was damaged by a secondary disease at the time of the operation – either by inflammation or by changes such as those occurring in the early stages of dementia. “In the case of these pre-existing conditions, the body’s own defenses are particularly active,” says Becker, who is also a member of the Transdisciplinary Research Center (TRA) “Life and Health”. “It is possible that the trauma during the surgical procedure further stimulates the immune system in the brain so that it attacks healthy brain tissue.”
Tests provide clues as to when surgery should be avoided
The researchers now want to examine samples from other epilepsy centers in order to substantiate their findings. The results could help to identify those affected for whom surgery should be avoided. “Today we have various diagnostic methods at hand that we can use for this purpose,” emphasizes Dr. Juri-Alexander Witt.
Before the operation, all patients complete an extensive battery of psychometric tests to determine their cognitive performance. In the synopsis of brain scanner recordings and the examination of the cerebrospinal fluid through a spinal cord puncture, some of the results already allow conclusions to be drawn about concomitant diseases. “If such tests indicate an inflammation or an incipient neurodegenerative disease, there are completely new treatment options – for example with anti-inflammatory drugs – that can make an operation unnecessary,” says Becker.
The study was funded by the German Research Foundation (DFG) and the Else Kröner-Fresenius Foundation as part of the doctoral program NeuroImmunology.
Scientific contacts:
PD Dr. Juri-Alexander Witt
Clinic and Polyclinic for Epileptology at the University Hospital Bonn
Tel. +49 (0)228-287-14436
E-Mail: juri-alexander.witt@ukbonn.de
Prof. Dr. Albert Becker
Institute for Neuropathology at the University Hospital Bonn
Tel. +49 (0)228-287-11352
E-Mail: albert_becker@uni-bonn.de
Originalpublikation:
Annika Reimers, Christoph Helmstaedter, Christian E. Elger, Julika Pitsch, Motaz Hamed, Albert J. Becker und Juri-Alexander Witt: Neuropathological insights into unexpected cognitive decline in epilepsy; Annals of Neurology; DOI:
literature on the topic
Heinen: Self-Action in Seizures Book 1-12
Patients ratgeber Epilepsy
Pabst, 2021