Does adding a sequence in brain MRI help in evaluation of seizures?

Abstract

Objective To evaluate the diagnostic utility of ‘Susceptibility Weighted Angiogram’ (SWAN) in brain magnetic resonance imaging (MRI) by identifying venous angiomas causing epileptic seizures. Method and Materials A retrospective observational study was performed in the Radiology department at King Fahad Military Medical Complex (KFMC) hospital in Dhahran from January 2016 to 2021. All consecutive adult patients who underwent brain MRIs for epilepsy with SWAN were included. Patients with brain tumors, traumatic brain injuries, and post-surgical cases were excluded. The presence of tuft of small deep parenchymal veins draining into a more prominent (transcortical or subependymal) collector vein as seen on SWAN image was considered a venous angioma and confirmed on either contrast-enhanced studies or cerebral angiograms. Two experienced neuroradiologists interpreted the studies with mutual consensus. The significance of such finding was considered if SWAN-detected venous malformation corresponded to an epileptiform focus on respective electroencephalogram (EEG). Findings were compared with incidentally detected venous angiomas in normal brain MRIs in patients without indications of seizures (control group, n=112). Proportion analysis (Z-test) was used to determine significance. Results Out of 112 patients, 64 were females (57%), and 48 were males (43%), with a mean age of 19.24 (range, 5-45 years). Twenty-three patients (epilepsy group) were found to have venous malformations while three (control group) had venous angiomas (Z-value, 3.93; P-value, 0.0008). Out of 23 patients, 20.53% were SWAN-detected venous angiomas, 5 corresponded to epileptiform foci on respective EEGs compared to none of 3 incidentally detected venous angiomas in the control group (p-value, 0.0005). Conclusion Venous angiomas are usually asymptomatic when detected incidentally. However, adding a SWAN sequence in routine brain MRI for epilepsy patients may help to detect venous angiomas, which may cause focal seizure activity in these patients.