Authors :
Presenting Author: Rodrigo Rocamora, MD, PhD – Hospital del Mar Barcelona
Laura Vilella, MD – Neurology – Hospital del Mar Barcelona; Nazaret Infante, MD – Neurosurgery – Hospital del Mar Barcelona; Fernando Muñoz, MD, PhD – Neurosurgery – Hospital del Mar Barcelona; Alessandro Principe, MD, PhD – Neurology – Hospital del Mar Barcelona; Gerardo Conesa, MD, PhD – Neurosurgery – Hospital del Mar Barcelona
Rationale:
Accurate quantification of seizures is essential for evaluating the management of epilepsy. Patient-reported seizures is the primary method for monitoring epilepsy. However, their accuracy can be highly compromised in certain cases. Ultralong subcutaneous electroencephalogram (sqEEG) monitoring provides a means to accurately assess seizures in real-life conditions, offering continuous monitoring. This study aimed to evaluate the utility of this technology in a cohort of patients for whom assessing seizure frequency was challenging and to make informed therapeutic decisions.
Methods:
Three patients diagnosed with DRE underwent implantation of sqEEG devices following VEEGM in our EMU. The average recording duration was 8.3 months, ranging from 114 to 399 days. The concordance between seizures reported by the patients and those detected by the sgEEG algorithm was notably low. Among the three patients, two exhibited a distinct circadian seizure pattern.
Results:
Patient 1: A 53-year-old female patient diagnosed with left posterior quadrant epilepsy (PQE) presented with MRI findings indicating a non-operable left posterior FCD. Living alone, she remained unaware of her seizures, which predominantly occurred during the nocturnal hours. The seizure diary documented six seizures over a span of 399 days, while automated sqEEG revealed nine events. Notably, these events did not align temporally. The EEG seizure rate per 24 hours of recording decreased from 0.07 to 0.03.
Patient 2: A 38-year-old patient with right PQE secondary to FCD type IIa, which coexisted with psychogenic nonepileptic seizures (PNES) and subclinical epileptic seizures after undergoing two epilepsy surgeries. The patient's diary recorded 304 seizures, all of which were PNES, while automatic sqEEG detected 697 subclinical events during nighttime monitoring. The EEG seizure rate per 24 hours of recording worsened significantly, increasing from 0.48 to 3.46. However, the patient perceived themselves as being seizure-free, as all events were presently subclinical. The patient experienced a notable reduction in PNES after participating in a stress management program.
Patient 3: A 31-year-old male patient with left PQE MRI negative, but FDG-PET revealed a left-sided temporal hypometabolism. VEEG confirmed also the coexistence PNES. The patient's diary recorded 12 seizures, while automatic sqEEG detected 31 events. However, the correspondence between them was limited. Notably, the EEG seizure rate per 24 hours of recording decreased during the last third of the monitoring period.
Conclusions: In the context of highly complex epilepsies, SqEEG monitoring unveiled a notable discrepancy between reported and recorded seizures. This technology proved valuable in differentiating PNES from epileptic events, offering patients a means to distinguish between these distinct phenomena. Furthermore, decisions regarding anti-seizure medication (ASM) adjustments could be grounded in objective seizure quantification and consideration of their circadian patterns. Importantly, none of the cases demonstrated intrusive effects from continued device usage, and the patients' overall quality of life remained unaffected.
Funding: None