Clinical course of poststroke epilepsy: a retrospective nested case-control study.

INTRODUCTION: Recently, several epidemiological studies have demonstrated that epilepsy develops after approximately 10% of all cerebrovascular lesions. With an aging population, poststroke epilepsy is likely to be of increasing relevance to neurologists and more knowledge on the condition is needed. Patients with poststroke epilepsy are likely to differ from other epilepsy patient populations regarding age, side-effect tolerability, comorbidities, and life expectancy, all of which are important aspects when counselling newly diagnosed patients to make informed treatment decisions. METHOD: We have here performed a nested case-control study on 36 patients with poststroke epilepsy and 55 controls that suffered stroke but did not develop epilepsy. The average follow-up time was between 3 and 4 years. RESULTS: In our material, two-thirds of patients achieved seizure freedom and 25% experienced a prolonged seizure (status epilepticus) during the follow-up period. Cases consumed more health care following their stroke, but did not suffer more traumatic injuries. Interestingly, the mortality among cases and controls did not differ significantly. This observation needs to be confirmed in larger prospective studies, but indicate that poststroke epilepsy might not infer additional mortality in this patient group with considerable comorbidities. CONCLUSIONS: The observations presented can be of value in the counselling of patients, reducing the psychosocial impact of the diagnosis, and planning of future research on poststroke epilepsy.

Complications to invasive epilepsy surgery workup with subdural and depth electrodes: a prospective population-based observational study.

OBJECTIVE: In some patients who undergo presurgical workup for drug-resistant epilepsy invasive seizure monitoring is needed to define the seizure onset zone and delineate eloquent cortex. Such procedures carry risks for complications causing permanent morbidity and even mortality. In this study, prospective data on complications in a national population-based sample were analysed. DESIGN: Complication data from the prospective Swedish National Epilepsy Surgery Register were analysed for 271 patients in whom therapeutic surgery was preceded by invasive monitoring 1996-2010. RESULTS: Complications occurred in 13/271 patients (4.8%). Subdural grids carried the highest risk of complications (7.4%). There was no surgical mortality or permanent morbidity. Subdural haematomas were most common (n=7) followed by epidural haematomas (n=3). Valproate treatment and having a haematoma was associated with an OR of 1.53 (CI 0.38 to 6.12) compared to having a haematoma without valproate treatment. Having a complication during invasive monitoring was associated with a significant OR of 6.27 (CI 1.32 to 29.9) of also having a complication at therapeutic surgery compared to the risk of having a complication only at surgery. CONCLUSIONS: In this prospective population-based epilepsy surgery series, the most common complications were haematomas, and subdural grids carried the highest risk. Close supervision and rapid interventions led to avoidance of permanent morbidity. The clinical implications of the slightly increased risk of haematomas with valproate treatment needs further investigation as does the finding of an increased risk for complications at epilepsy surgery for patients who had a complication during invasive monitoring.