Diagnostic yield of utilizing 24-72-hour video electroencephalographic monitoring in the diagnosis of seizures presenting as paroxysmal events in resource-limited settings.

Abstract

Objective: Long-term video electroencephalogram monitoring (LTVEM) is a standard practice in epilepsy centers to diagnose and characterize paroxysmal events. With the lack of data on LTVEM in Africa, we aimed to determine the clinical yield of LTVEM performed for 24-72 h to diagnose seizures in an epilepsy center in Nigeria.

Methods: This was a retrospective review of all patients admitted to our Epilepsy Monitoring Unit (EMU) from September 2018 to September 2021, with monitoring lasting between 24 and 72 h. We reviewed the patients' seizure semiology, time to the first event, and final diagnosis. The frequency of seizures was classified as "daily" in patients with one or more seizures per day, "persistent" in patients with less than one seizure per day but at least once in 6 months, and "rare" in patients with less than one seizure in 6 months. Patients with unclear duration due to recent onset were classified as "undefined".

Results: Seventy patients (34 males, 36 females) were included in our study. The mean age was 22.86 ± 18.00 years. The average duration of monitoring was 44.23 ± 16.16 h. Fifty-seven patients (81.4%) were confirmed to have seizures. Thirteen patients experienced non-epileptic events. Of these 13 patients, nine were diagnosed with psychogenic non-epileptic spells (PNES). Two patients were diagnosed with essential myoclonus and two patients were diagnosed with syncope. The time to the first interictal epileptiform discharge was within 8 h. In the first 24 h, 56 of 57 patients had ictal and interictal discharge (98.2%). These included 100% daily seizures, 100% persistent seizures, and 100% undefined events. One rare seizure was observed within 48 h.

Significance: The diagnostic yield of the LTVEM in well-selected patients for seizures in this study is 81.4%. Most patients received a diagnosis within 48 h of monitoring, and we found that extending the study beyond 72 h may not offer significant additional benefits in diagnosing seizures in patients presenting with paroxysmal events.

Plain language summary: There is limited information about the usefulness of long-term video electroencephalogram (EEG) monitoring in diagnosing seizures in Africa. Several conditions that resemble seizures (paroxysmal events) could be misdiagnosed, leading to inappropriate treatment. This study evaluated the effectiveness of 24- to 72-h video EEG monitoring in diagnosing seizures at an epilepsy center in Nigeria. Among 70 patients, 81.4% were diagnosed with seizures, with most diagnoses made within 48 h. The findings suggest that video EEG performed within 48 h can significantly help distinguish seizures from other paroxysmal events, thereby contributing to better management and outcomes.