A 9-year-old boy is brought to the pediatric clinic after a nocturnal seizure characterized by hemifacial twitching, drooling, and speech arrest lasting 2 minutes, followed by secondary generalization. Neurological examination and brain MRI are normal. EEG shows a normal background with high-amplitude diphasic sharp waves maximal over the central and midtemporal electrodes. The structure marked **C** in the diagram (centrotemporal high-amplitude diphasic sharp waves markedly activated by drowsiness and sleep) is most consistent with which diagnosis?
A. Childhood Absence Epilepsy
B. Juvenile Myoclonic Epilepsy
C. Benign Epilepsy with Centrotemporal Spikes (BECTS/Benign Rolandic Epilepsy)
D. Temporal Lobe Epilepsy with mesial temporal sclerosis
Explanation
Why Benign Epilepsy with Centrotemporal Spikes (BECTS/Benign Rolandic Epilepsy) is right
The clinical presentation—nocturnal seizure with hemifacial twitching, drooling, anarthria, and secondary generalization in a healthy 9-year-old—combined with the EEG finding of high-amplitude diphasic centrotemporal sharp waves markedly activated by drowsiness and sleep is pathognomonic for BECTS. This is the most common idiopathic focal epilepsy of childhood (15–25% of childhood epilepsies), with peak onset at 7–10 years. The stereotyped EEG morphology (high-voltage diphasic spike followed by slow wave, dramatically enhanced during sleep) is the diagnostic hallmark. Seizures are typically nocturnal or on awakening and involve the orofacial region. Prognosis is excellent with spontaneous remission by age 15–16 years.
Why each distractor is wrong
Juvenile Myoclonic Epilepsy: Presents with myoclonic jerks on awakening, typically in adolescents (10–20 years), not nocturnal focal seizures with hemifacial twitching. EEG shows generalized 3–4 Hz spike-and-wave, not centrotemporal spikes activated by sleep.
Childhood Absence Epilepsy: Characterized by brief staring spells (5–10 seconds) with impaired consciousness, not focal motor seizures with speech arrest. EEG shows generalized 3 Hz spike-and-wave activated by hyperventilation (option A), not centrotemporal spikes.
Temporal Lobe Epilepsy with mesial temporal sclerosis: Presents with focal seizures arising from the temporal lobe with automatisms and altered consciousness, often with a history of febrile seizures. Brain MRI would show hippocampal atrophy or signal change. EEG shows temporal lobe spikes, not centrotemporal spikes activated by sleep.
High-YieldNEET PG
BECTS is diagnosed by the combination of: (1) focal nocturnal or awakening seizures with orofacial features and secondary generalization, (2) normal neuroimaging, and (3) centrotemporal high-amplitude diphasic spikes markedly activated by sleep on EEG—prognosis is excellent with spontaneous remission by mid-adolescence.
ILAE Classification (2017); Nelson Pediatrics, Childhood Focal Epilepsies
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