Age, Lesion Volume Influence Epilepsy Risk After Stroke

HOUSTON – Age and lesion volume affect risk of development and severity of post-stroke epilepsy in patients who experience chronic stroke, according to data presented at the 2016 American Epilepsy Society Annual Meeting.¹

While stroke is the cause behind up to 45% of cases of epilepsy in individuals older than 60, the mechanism behind that development is not well understood.

In order to better understand how stroke characteristics affect epilepsy risk, a team of researchers led by Beate Diehl, MD, PhD, FRCP, of the University College London Institute of Neurology, identified 450 patients with a history of stroke from the Predicting Language Outcome and Recovery After Stroke (PLORAS) database with available data on seizure occurrence. High-resolution MRI was obtained with a 3 Tesla scanner, and lesions were identified and mapped to examine overlap at different voxel levels.

Of the 450 patients included in the analysis, 369 had left hemispheric stroke (LHS) and 81 had right hemispheric stroke (RHS). Forty-two patients in the LHS group had post-stroke epilepsy compared to 9 patients in the RHS group. Notably, patients who developed post-stroke epilepsy were significantly younger than those who did not (44±13 vs 56±13, P< .0001) and had significantly larger lesions (148±101 cm³ vs 73±87, P< .0001). The most commonly affected areas of the brain in both groups included the basal ganglia (globus pallidus and caudate nucleus) and several nuclei of the thalamus, including the anterior and ventral nuclei and posterior regions, including the pulvinar.

Lesion analysis revealed that 64% of patients with LHS and post-stroke epilepsy sustained damage in the basal ganglia in the left hemisphere, though 17% of patients with LHS and no history of post-stroke epilepsy also had damage in this region. Overall, damage to this region was associated with post-stroke epilepsy in 33% of patients with LHS.

The results suggest that clinicians should keep in mind that post-stroke epilepsy is common and can “negatively affect stroke recovery and rehabilitation,” Dr Diehl said in a statement.²

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References

1. Diehl B, Wandschneider B, Leff A, Chaudhary U, Lemieux L, Price C. Risk factors to develop post stroke epilepsy: epidemiology and lesion mapping. Presented at: 2016 American Epilepsy Society Annual Meeting; December 2-6, 2016; Houston, TX. Abstract 1.008.
2. 11 percent of stroke sufferers develop epilepsy, research shows. Younger age, more brain damage increase risk [press release]. Houston, TX: American Epilepsy Society; December 3, 2016.