Seizure frequency reduction after sinus stent placement in patients with venopathic intracranial hypertension–associated encephaloceles: a case series

OBJECTIVE: Cerebral encephaloceles are being recognized as an etiology of drug-resistant epilepsy (DRE). Neuroimaging suggests a link between idiopathic intracranial hypertension (IIH), dural sinus stenosis (DSS), and encephaloceles. One hypothesis is that pulsatile CSF forces, secondary to elevated intracranial pressure, contribute to forming prominent arachnoid villi, which create pockets of CSF and develop encephaloceles. The impact of DSS and IIH management with stent placement for seizure control in patients with DRE and encephaloceles remains poorly understood. In this study, the authors explored the clinical outcomes in this patient population. METHODS: This single-center case series retrospectively analyzed seizure frequency in 12 patients with DRE due to encephaloceles associated with IIH who underwent cerebral venous sinus stent placement between 2018 and 2024 at the University of Kansas Medical Center. Seizure burden was assessed after stent placement. RESULTS: Twelve patients with encephaloceles and DRE met the inclusion criteria. The mean age was 49 years, and 9 patients were female. The mean BMI was 36.7 kg/m2. The mean age of seizure onset was 42.1 years. All patients had signs of IIH on MRI of the brain: empty sella (n = 8), transverse sinus stenosis (n = 12), and enlarged arachnoid granulations (n = 5). Seven patients underwent lumbar puncture with a mean opening pressure of 27.25 cm H2O. All patients had unilateral temporal lobe epilepsy and encephaloceles involving a sphenoid wing. One patient (8.3%) had an additional lesion in the basal temporal lobe, and another patient (8.3%) had bilateral cerebellar encephaloceles. The mean pre-stent venous pressure gradient was 14.25 mm Hg, and the mean post-stent gradient was 1.25 mm Hg; 50% of patients had a post-stent pressure gradient of 0 mm Hg. Following venous sinus stent insertion and additional surgical interventions, the mean seizure frequency decreased to 0.9 seizures per month. Eleven patients (91.7%) experienced > 50% reduction in seizure frequency postprocedure. CONCLUSIONS: The impact of endovascular stent placement for DSS and IIH on seizure burden was investigated. Seizure frequency reduction was observed in all patients. This study demonstrates a prominent role of endovascular stent insertion in patients with encephaloceles and DRE that warrants further exploration.