HOUSTON — Researchers may have identified a common pathologic lesion in many patients with post-stroke epilepsy (PSE).

Their study also showed that lesion size and a patient’s age may be other factors affecting risk for PSE.

The study was presented here by lead author Beate Diehl, MD, PhD, reader, University College London Institute of Neurology, United Kingdom, at the American Epilepsy Society (AES) 2016 Annual Meeting.

The analysis included 450 stroke survivors from an existing database — Predicting Language Outcome and Recovery After Stroke (PLORAS) — that contains high-resolution MRI scans. None of the study patients had a history of epilepsy before their stroke.

Of the total, 369 patients had sustained a left hemispheric stroke (LHS), of whom 11.4% had PSE, and 81 had a right hemispheric stroke, 11.1% of these with PSE.

Those with and without PSE were similar regarding sex and handedness.

Size Matters

Looking at the size of the lesion, investigators found that patients with PSE had significantly larger lesions than those without PSE (148 cm vs 73 cm; P < .0001).

“We found that lesion size clearly matters,” said Dr Diehl.

When examining mapping of the lesion location, the researchers found that one particular region, which “fits in the periventricular area, but also touches on the parahippocampal gyrus,” seemed to be important, said Dr Diehl.

The parahippocampal gyrus is a gray matter cortical region of the brain that surrounds the hippocampus.

Of the 42 patients with LHS who had damage in that region, 27 (64%) developed PSE. However, 55 of 327 (17%) of patients with LHS who didn’t develop epilepsy also had damage in that region.

“If you look at all the patients who had damage to this region, 33% of them then had post-stroke epilepsy,” said Dr Diehl.

It’s not entirely clear why lesions in this region make some patients more susceptible to epilepsy, she said. “You could obviously speculate that perhaps the proximity to the parahippocampal gyrus and to the hippocampus might play a role, but I don’t think this study can determine that.”

She also stressed that not all patients experiencing damage in this region developed epilepsy.

CONTINUE READING AT SOURCE: http://www.medscape.com/viewarticle/874051