History: Terrors at age 8
Ms. J, age 35, began having sleepwalking episodes at age 8. At times they involved odd behaviors, such as carrying her brother’s shirt into the bathroom, placing it into the sink, and turning on the water.
As a child, Ms. J also began experiencing nocturnal awakenings characterized by panic and shouting. She sometimes saw a frightening image, usually of something falling on her. She would promptly return to sleep after each incident and had trouble remembering the event the next morning. The sleepwalking and awakening occurred monthly—more often when she was under stress or fatigued—until her early 20s.
At age 21, Ms. J. was under severe stress while preparing for a crucial graduate school examination and was losing much sleep. At this point, the episodes began to occur once or twice nightly.
She consulted a sleep specialist. EEG results were normal, but a sleep study was not helpful because she experienced no events that night. The specialist diagnosed Ms. J as having night terrors and prescribed clonazepam, 0.5 mg nightly. The agent did not prevent the events, but their frequency returned to baseline after Ms. J took her exam.
Were Ms. J’s clinical presentation and course consistent with night terrors? How would you treat her symptoms at this point?
The authors’ observations
Night terrors are an arousal disorder that usually begins in early childhood and affects 1% to 4% of the population.1 The disorder usually disappears before puberty.
Episodes of this parasomnia typically occur one to four times each month and can last several minutes. They are characterized by sudden awakenings with panic, disorientation, vocalization, and autonomic discharge. Patients sometimes see a frightening image. The events occur in stage 4 sleep, usually soon after falling asleep. Disorientation and a prompt return to sleep may follow.2 Sleeptalking and sleepwalking may also be present. The patient often cannot remember the event the next morning.
At this point, night terrors are a reasonable explanation for Ms. J’s nocturnal phenomena. Benzodiazepines, especially clonazepam, have been shown to decrease night terror frequency.3
Continued history: A new mother’s stress
At age 34, Ms. J gave birth to her first child. Weeks later, the nocturnal events began to occur at least three times nightly—every hour on some nights. Because their frequency disrupted her sleep, Ms. J constantly felt tired. Stress, emotional upset, and sleep deprivation exacerbated the events, which were stereotypical and included:
- sudden jerking of the right upper and/or lower extremities
- sudden sitting up and posing with the right arm flexed and internally rotated
- hallucinations of spiders or people
- sudden body flexion accompanied by an “electric shock” sensation in the head
- sitting up in bed, touching and picking at the sheets
- nonsensical speech after sitting up in bed
- sudden fear that Ms. J’s baby was hurt or dead, accompanied by searching the bed and under the pillow for the baby
- episodes of panic often accompanied by crying out, jumping out of bed and—in some cases—running.
Several times she ran down the stairs and out of the house while asleep. During one event, she jumped out of bed and fractured her foot. In another, she jumped from the bed and ran headfirst into a wall, causing bruising but no severe injury.
Each event was accompanied by confusion for 10 seconds to 3 minutes. Ms. J remembered about one-half the events; her husband described the remainder. She invariably returned to sleep immediately after each event.
A second sleep specialist diagnosed Ms. J as having night terrors. Unsatisfied with the diagnosis, she consulted a neurologist who specialized in epilepsy. The neurologist diagnosed her as having nocturnal frontal lobe epilepsy (NFLE) based on her history. A video EEG study—which showed spike and wave activity in the left frontal lobe during the nocturnal events—confirmed the diagnosis. The events all occurred during stage 2 sleep.
Is Ms. J’s latest diagnosis on target? Which clinical features in her case would differentiate sleep epilepsy from parasomnias?
The authors’ observations
Frontal lobe epilepsy can take many forms. Seizures can occur during sleep and/or while awake and consist of sudden, brief (<1 minute) motor attacks occurring in clusters. The prevalence of sleep epilepsy among persons with seizure disorders has been estimated at 7.5% to 45%, based on studies of small patient populations.4
Nocturnal frontal lobe seizures:
- occur only in non-REM (usually stage 2) sleep.
- can occur at any time of night
- usually begin in middle childhood to early adolescence, but onset in early childhood or adulthood has been reported.5 Seizures usually subside during adulthood (Table).6
Table
Characteristics of parasomnias and nocturnal epilepsy