Seizures are common in cerebral venous thrombosis (CVT). The occurrence of acute symptomatic seizures (ASS) has implications for patients’ management, with some patients developing unprovoked late seizures (ULS). We aimed to determine risk factors for the development of ASS, ULS, and seizure recurrence (SR) in patients with CVT.

We performed an observational retrospective analysis of 141 patients with CVT. We recorded the occurrence of seizures, their time relation to the first-symptom onset, and their relation with demographic, clinical, CVT risk factors, and radiological findings. Seizure recurrence (total recurrency, recurrent ASS, and recurrent LS), potential risk factors, and the use of antiepileptic drugs (AED) were also analysed.

Thirty-two (22.7%) patients developed seizures: 23 (16.3%) were ASS and 9 (6.3%) ULS. After multivariable logistic regression, seizure patients had more focal deficits (p = 0.033), parenchymal lesion (p < 0.001), sagittal sinus thrombosis (p = 0.007). In ASS, more frequent focal deficits (p = 0.001), encephalopathy (p = 0.001), mutation in V Leiden factor (p = 0.029), and parenchymal brain lesions (p < 0.001) were observed. ULS patients were younger (p = 0.049) and took more hormonal contraceptives (p = 0.047). Thirteen (9.2%) patients suffered SR (2 recurrent ASS only, 2 recurrent LS only, 2 both acute and recurrent LS), which was more frequent in patients with focal deficits (p = 0.013), infarct with haemorrhagic transformation (p = 0.002), or previous ASS (p = 0.001).

The occurrence of seizures in patients with CVT is related to focal deficits, structural parenchymal lesions, and superior sagittal sinus thrombosis. SR is frequent, even in patients under AED. This shows the important impact that seizures have on CVT and its long-term management.