Acute symptomatic seizures in cerebral venous thrombosis.

OBJECTIVE: To 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. METHODS: We defined ASS as any seizure between symptom onset and 7 days after diagnosis of CVT. We stratified ASS into prediagnosis and solely postdiagnosis ASS. Status epilepticus (SE) was also analyzed separately. We analyzed predictors for ASS and the association between ASS and clinical outcome (modified Rankin Scale) with multivariable logistic regression. RESULTS: Of 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 postdiagnosis 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 was independently associated with outcome. CONCLUSION: ASS occurred in one-third of patients with CVT and was associated with brain parenchymal lesions and thrombosis of the superficial system. In the absence of prediagnosis ASS, no subgroup was identified with sufficient risk of postdiagnosis ASS to justify prophylactic antiepileptic drug treatment. We found no association between ASS and outcome.

Late seizures in cerebral venous thrombosis.

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 12 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 ≥1 LS (incidence rate for first LS 30 per 1,000 person-years, 95% confidence interval [CI] 25-35). Median time to first LS was 5 months (IQR 1-16 months). Baseline predictors of LS included status epilepticus in the acute phase (hazard ratio [HR] 7.0, 95% CI 3.9-12.6), decompressive hemicraniectomy (HR 4.2, 95% CI 2.4-7.3), acute seizure(s) without status epilepticus (HR 4.1, 95% CI 2.5-6.5), subdural hematoma (HR 2.3, 95% CI 1.1-4.9), and intracerebral hemorrhage (HR 1.9, 95% CI 1.1-3.1). Eighty-five patients (70% of patients with LS) experienced a recurrent seizure during follow-up, despite the fact that 94% received antiepileptic drug treatment after the first LS. CONCLUSION: During a median follow-up of 2 years, ≈1 in 10 patients with CVT had LS. Patients with baseline intracranial bleeding, patients with 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.