LETTER TO THE EDITOR
Revisiting Post-stroke Epilepsy
Department of Neurology, Government Stanley Medical College, Chennai, Tamil Nadu, India
Corresponding Author: Corresponding Author: K Malcolm Jeyaraj, Department of Neurology, Government Stanley Medical College, Chennai, Tamil Nadu, India, Phone: +91 9443390767, e-mail: email@example.com
How to cite this article: Jeyaraj KM. Revisiting Post-stroke Epilepsy. Bengal Physician Journal 2020;7(1):22.
Source of support: Nil
Conflict of interest: None
Post-stroke epilepsy is one of the common causes of seizures in the adult population. Nearly 5–20% of all individuals who have a stroke will have subsequent seizures.1 Post-stroke seizure could be early or late. Early post-stroke seizures occur in around 3–6% of ischemic and 10–16% of hemorrhagic stroke. Late post-stroke seizures occur in around 6% of ischemic and 12% of hemorrhagic strokes over a 5–10-year follow-up period.2 There is wide variation in various studies regarding post-stroke seizures due to stroke etiology, study methodology, definitions of early and late unprovoked seizures, the timing of antiepileptic drug administration, small sample size, and ambiguities in seizure identification. The risk factors for early post-stroke seizures in ischemic stroke could be male population, hemorrhagic transformation, cortical location of the stroke, atrial fibrillation, severe stroke (NIHSS (National Institutes of Health stroke scale) >11), partial seizures, status epilepticus, and abnormal electroencephalogram (EEG).3 The risk factors for recurrence of early seizures in hemorrhagic stroke could be cortical location, age less than 65 years, status epilepticus, hemorrhagic volume >10mL, and abnormal EEG.2,3 In the absence of RCTs a strong recommendation cannot be made on the initiation of antiepileptic drugs for secondary prophylaxis of early post-stroke seizures. However in practicality when antiepileptic drugs are initiated after acute symptomatic seizures, they should not be continued more than a month of therapy.
In the study by Hesdorffer et al. the 10-year recurrence rate of late unprovoked seizure after one post-stroke, the unprovoked seizure is around 70%.4 As per the recent definition of epilepsy a single unprovoked late post-stroke seizure is equivalent to post-stroke epilepsy.
In this context, there are certain prediction tools for the assessment of seizure recurrence risks namely the CAVE score and SELECT score. In the CAVE score the following points namely cortical involvement, age <65 years, volume >10 mL, and early seizures are noted and if all the four points are present the 5-year recurrence risk of seizures in hemorrhagic stroke is around 46%.5 Similarly in ischemic stroke the SELECT score gives a risk stratification for recurrence of unprovoked seizures following an ischemic stroke.6 The SELECT score includes the severity of the stroke, large artery atherosclerosis, early seizures, cortical involvement, and MCA territory involvement. The maximum score could be nine which suggests a 5-year recurrence rate at 83%.
The given study which is probably a descriptive study shows nearly three-fourth of patients with post-stroke seizures being hemorrhagic which is slightly higher than the existing data in the literature. Nearly two-thirds of the patient developed post-stroke seizures. As already pointed post-stroke seizures remain the commonest cause for new-onset seizures in the elderly population. In the given study nearly 24 out of the 34 patients fall in the age group between 60 years and 80 years of age. In the SELECT score, the cortical location and MCA territory are two important variables that stratify risk. In the given study, the majority of the patients with stroke had cortical involvement namely MCA territory strokes.
The above study has made certain critical cross-sectional observations on the demographic/risk factors for post-stroke epilepsy. However, a prospective follow-up study would help in elucidating more Indian data in this regard.
1. Silverman IE, Restrepo L, Mathews GC. Poststroke seizures. Arch Neurol 2002 Feb;59(2):195–201. DOI: 10.1001/archneur.59.2.195.
2. Holtkamp M, Beghi E, Benninger F, et al. European Stroke Organisation guidelines for the management of post-stroke seizures and epilepsy. Eur Stroke J 2017 Jun;2(2):103–115. DOI: 10.1177/2396987317705536.
3. Mecarelli O, Pro S, Randi F, et al. EEG patterns and epileptic seizures in acute phase stroke. Cerebrovasc Dis 2011;31(2): 191–198.DOI: 10.1159/000321872.
4. Hesdorffer DC, Benn EK, Cascino GD, et al. Is a first acute symptomatic seizure epilepsy? Mortality and risk for recurrent seizure. Epilepsia 2009 May;50(5):1102–1108. DOI: 10.1111/j.1528-1167.2008.01945.x.
5. Haapaniemi E, Strbian D, Rossi C, et al. The CAVE score for predicting late seizures after intracerebral hemorrhage. Stroke 2014 Jul;45(7):1971–1976. DOI: 10.1161/STROKEAHA.114.004686.
6. Galovic M, Döhler N, Erdélyi-Canavese B, et al. Prediction of late seizures after ischaemic stroke with a novel prognostic model (the SeLECT score): a multivariable prediction model development and validation study. Lancet Neurol 2018 Feb;17(2):143–152. DOI: 10.1016/S1474-4422(17)30404-0.
© The Author(s). 2020 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted use, distribution, and non-commercial reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.