Case 41. Night Terrors Are Not Always What They Seem

Abstract

NREM parasomnias and nocturnal epileptic seizures (especially frontal lobe seizures) share clinical similarities which may lead to misdiagnosis and delayed treatment. Sleep-related hypermotor epilepsy (SHE), formerly termed nocturnal frontal lobe epilepsy (NFLE), is characterized by bizarre motor behavior and autonomic activation, appearing almost exclusively during sleep particularly N2 sleep stage. Night terrors typically begin after an arousal from N3 slow wave sleep, although occasionally may emerge from stage N2 sleep. Both are characterized by complex hypermotor, behavior, altered responsiveness and amnesia for the episode, with seizures exhibiting a more stereotypic motor pattern. NREM parasomnias as well as frontal lobe epilepsy (FLE) are more prevalent among children and young adults, but onset at any age can be seen especially with nocturnal frontal seizures. Stress, sleep deprivation, or irregular sleep-wake rhythm may provoke seizures as well as NREM parasomnias. A genetic predisposition plays an important role in disorders of arousals as well as in some nocturnal epilepsy types, such as SHE. There may be an occasional co-occurrence of focal seizures with new onset NREM related parasomnias (night terrors) making the diagnosis even more challenging. A Polysomnogram (PSG) with full electroencephalogram (EEG) montage is useful in differentiating between the two.