Background and purpose Clinical features of epileptic seizures after cerebral venous sinus thrombosis (CVST) among Chinese patients are not known, and it is still controversial whether seizures would affect the outcome of CVST.

Methods In a Chinese hospital-based study of consecutive patients with CVST between 2003 and 2015, we described the clinical features of seizures and determined the predictors of seizure onset using multivariable logistic regression analysis. We also compared the in-hospital case-fatality and short-term functional outcome (modified Rankin Scale (mRS) at discharge) in patients with versus without seizures using ordinal regression analysis.

Results Among 151 patients with CVST, 52 (34.4%) presented seizures, of which 42 (80.8%) were generalised seizures. Male gender (OR 6.32, 95% CI 2.06 to 19.35, p=0.001), motor deficits (OR 4.89, 95% CI 1.52 to 15.68, p=0.008), intracerebral haemorrhage (OR 3.93, 95% CI 1.16 to 13.26, p=0.027), cerebral infarction (OR 3.78, 95% CI 1.15 to 12.36, p=0.029) and superior sagittal sinus thrombosis (OR 3.38, 95% CI 91.16 to 9.86, p=0.026) were independent predictors for seizures. The overall in-hospital case-fatality rate was 2.0% (3/151), and 21 (13.9%) had mRS >2 at discharge. Compared with patients without seizures, patients with seizures were more likely to have a worse outcome (p=0.02) at discharge, independent of age, gender, clinical presentation, clot burden and presence of parenchymal lesions.

Conclusions In Chinese Han patients, compared with patients without seizures, patients with seizures after CVST had a worse outcome. Risk factors such as male gender, paresis, parenchymal lesion and superior sagittal sinus thrombosis were independently associated with seizure onset after CVST. Generalised seizure was the main form of seizures after CVST, which was obviously different to seizures after strokes of arterial origin.