Occipital
epilepsy is an uncommon and likely underdiagnosed type of
epilepsy that is often misdiagnosed as a
migraine with aura. High clinical suspicion and subsequent electroencephalogram (EEG) and brain imaging lead to early diagnosis. Methods: We recruited patients with occipital
epilepsy based on visual semiology, structural abnormalities in the occipital region, or EEG changes who visited the Department of Neurology of Dhaka Medical College from June 2019 to January 2020. We documented the presentations, etiology, and outcomes at the 12-month follow-up. Additionally, we compared the clinical features of patients with occipital
epilepsy (n = 10) and those with
migraine with aura (n = 18).
RESULTS: We identified three and seven cases of idiopathic and symptomatic occipital
epilepsy, respectively, all presenting with visual semiology. Symptomatic occipital
epilepsy occurred due to space-occupying lesions, post-hypoxic damage, post-
stroke encephalomalacia, gyral calcification from
Sturge-Weber syndrome, and
Wilson's disease. Age, sex, illness duration,
headache severity, and associated features were similar between the
migraine with aura and
epilepsy groups. In occipital
epilepsy, the median (IQR) age was 22 (15-47) years, and the patients were predominantly female (8, 80%). The visual
auras lasted 35 (3-375) seconds and included colored dots or light flashes that persisted for seconds (50%) before (60%), during (30%), and after (10%) the
headache. Compared to
migraines, the
headaches were global (90%), compressive (90%), and of shorter duration (210 minutes, IQR: 150-630). Except for
nausea or osmophobia,
vomiting (80%),
photophobia (80%), and
phonophobia (70%) occurred. Most cases had associated focal or bilateral
tonic-clonic seizures (60%; p-value < 0.001). In contrast, the visual
auras in
migraine were
scotomas, white or golden dots, or light flashes lasting for minutes (83.3%; p-value = 0.02) before the
headache. The
headaches lasted longer (720 minutes, IQR: 345-1,440, p-value < 0.03), were unilateral (44%) or bilateral (50%), and throbbing (72%; p-value = 0.003).
Headache was associated with
photophobia (94.4%; p-value = 0.28),
phonophobia (88.9%; p-value 0.31), and osmophobia (38.9%; p-value 0.03); no associated convulsions occurred. At the 12-month follow-up, most occipital
epilepsy patients (9, 90%) responded well to
carbamazepine.
CONCLUSIONS: