HOUSTON -- Physicians should be on the lookout for epilepsy after chronic stroke, particularly in younger stroke patients and those with more brain damage, researchers reported here.
In a retrospective U.K. study cohort, about 11% of stroke patients developed post-stroke epilepsy (PSE), according to , of University College London (UCL), and colleagues at the American Epilepsy Society meeting.
Those who developed PSE were younger (44 versus 56) and had more extensive brain damage on MRI scans, they added.
Action Points
- Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
"Many physicians treating stroke patients don't realize that falls, episodes of confusion, and loss of consciousness may be signs of post-stroke epilepsy," Diehl said in a statement. "Post-stroke epileptic seizures can negatively affect stroke recovery and rehabilitation."
Epilepsy often goes undiagnosed in the elderly, the researchers said. The leading cause of epilepsy in these older patients is stroke, which accounts for as much as 45% of epilepsy in people over age 60.
Although some risk factors for PSE have been identified, the exact mechanisms by which stroke causes epilepsy aren't known, Diehl and colleagues said. So they looked at data from the Predicting Language Outcome and Recovery After Stroke () database of more than 1,000 stroke patients in the U.K.
About 450 of these patients had 1 mm 3-voxel T1-weighted anatomical whole-brain scans acquired with a 3T MRI scanner at the UCL . Patients also answered questions about having seizures.
Overall, the researchers found that of the 369 patients who had left hemisphere strokes, 42 of them (11.4%) developed PSE.
The figure was similar for the 81 who had right-hemisphere strokes: nine of these patients (11.1%) developed PSE.
Patients who developed PSE were significantly younger than those without PSE (44 versus 56, P<0.0001), and PSE patients had twice the extent of brain damage of those without epilepsy -- their lesions were significantly larger (148 cm3 versus 73 cm3, P<0.0001) -- suggesting that the frequency of epilepsy increases with the size of the lesion.
When comparing lesion locations between PSE and non-PSE patients with left hemisphere stroke, the researchers found a region that was damaged in 64% of those with PSE, but this area was also damaged in 17% of those without PSE.
The authors said the incidence of PSE after damage to this region was only 33%.
Among those who had left hemispheric stroke and developed PSE, the most commonly affected areas of the brain were the basal ganglia -- particularly the globus pallidus and caudate nucleus -- and most nuclei of the thalamus (the anterior and ventral nuclei, as well as posterior regions including the pulvinar). The authors noted that these are important areas for controlling movement, sensation, and consciousness.
Their findings are in line with recent reports of a higher percentage of stroke patients developing epilepsy, they said, and concluded that doctors treating stroke patients should keep in mind that PSE is common, so they should watch for risk factors, such as extent of brain damage and younger age.
Disclosures
The study was supported by Epilepsy Research UK and the National Institute for Health Research UCL Hospitals Biomedical Research Center.
Diehl and co-authors disclosed no relevant relationships with industry.
Primary Source
American Epilepsy Society
Diehl B, et al "Risk factors to developing post stroke epilepsy: Epidemiology and lesion mapping" AES 2016; Abstract 1.008.