ObjectiveTo identify characteristics, predictors, and outcomes of acute symptomatic seizures (ASS) in cerebral venous thrombosis (CVT), we investigated 1,281 consecutive adult patients with CVT included from 12 hospitals within the International CVT Consortium.MethodsWe defined ASS as any seizure between symptom onset and 7 days after diagnosis of CVT. We stratified ASS into pre-diagnosis and solely post-diagnosis ASS. Status epilepticus (SE) was also analyzed separately. We analyzed predictors for ASS, and association between ASS and clinical outcome (modified Rankin Scale) with multivariable logistic regression.ResultsOf 1,281 eligible patients, 441 (34%) had ASS. Baseline predictors for ASS were intracerebral hemorrhage ([ICH], adjusted odds ratio [aOR] 4.1, 95% confidence interval [CI] 3.0–5.5), cerebral edema/infarction without ICH (aOR 2.8, 95% CI 2.0–4.0), cortical vein thrombosis (aOR 2.1, 95%CI 1.5–2.9), superior sagittal sinus thrombosis (aOR 2.0, 95% CI 1.5–2.6), focal neurologic deficit (aOR 1.9, 95% CI 1.4–2.6), sulcal subarachnoid hemorrhage (aOR 1.6, 95% CI 1.1–2.5) and female-specific risk factors (aOR 1.5, 95% CI 1.1–2.1). Ninety-three (7%) patients had solely post-diagnosis ASS, best predicted by cortical vein thrombosis (positive/negative predictive value 22%/92%). Eighty (6%) patients had SE, independently predicted by ICH, focal neurologic deficits and cerebral edema/infarction. Neither ASS nor SE were independently associated with outcome.ConclusionASS occurred in 1/3 of patients with CVT and was associated with brain parenchymal lesions and thrombosis of the superficial system. In absence of pre-diagnosis ASS, no subgroup was identified with sufficient risk of post-diagnosis ASS to justify prophylactic antiepileptic drug treatment. We found no association between ASS and outcome.

Objective:To examine the incidence, characteristics, treatment, and predictors of late seizures (LS) after cerebral venous thrombosis (CVT), we described these features in a registry of 1,127 patients with CVT.Methods:We included consecutive adult patients from an international consortium of twelve hospital-based CVT registries. We excluded patients with a history of epilepsy or with <8 days of follow-up. We defined LS as seizures occurring >7 days after diagnosis of CVT. We used multivariable Cox regression to identify predictors of LS.Results:We included 1,127 patients with CVT. During a median follow-up of 2.0 years (interquartile range [IQR] 1.0-6.3), 123 patients (11%) experienced one or more LS (incidence rate for first LS 30 per 1,000 person-years, 95%CI 25-35). Median time to first LS was 5 months (IQR 1-16). Baseline predictors of LS included status epilepticus in the acute phase (Hazard Ratio [HR] 7.0, 95%CI 3.9-12.6), acute seizure(s) without status epilepticus (HR 4.1, 95%CI 2.5-6.5), intracerebral hemorrhage (HR 1.9, 95%CI 1.1-3.1), subdural hematoma (HR 2.3, 95%CI 1.1-4.9) and decompressive hemicraniectomy (HR 4.2, 95%CI 2.4-7.3). Eighty-five patients (70% of patients with LS) experienced a recurrent seizure during follow-up, despite the fact that 94% received anti-epileptic drug treatment after the first LS.Conclusion:During a median follow-up of two years, approximately one in ten patients with CVT had LS. Patients with baseline intracranial bleeding, acute symptomatic seizures, and those who underwent decompressive hemicraniectomy were at increased risk of developing LS. The high recurrence risk of LS justifies epilepsy diagnosis after a first LS.