Somnambulism or Nocturnal Frontal Lobe Epilepsy?
Dr Zainab Abd Majeed,
Senior Lecturer in Psychiatry,
International Medical University,
Dr Norizam Md Alias,
Hospital Tuanku Jaafar,
Somnambulism or sleep walking is a disorder of arousal which is classified as parasomnia. It is defined as abnormal movements or behaviours that intrude into sleep intermittently or episodically during the night (Ackroyd G. et al, 2007). It can be a primary phenomena or secondary to systemic disease. This case report highlights repetitive behaviour in a patient with somnambulism.
A 14-year-old boy, still studying, was referred from an out patient clinic as a case of schizophrenia. The history was mainly taken from his mother. He presented with 4 months history of sleep walking which occurred every night, with 3 to 4 episodes per night. The episodes of walking in his sleep would be only at night, within the first 3 hours of sleep. During those episodes, he would be walking to the bathroom, which is next to his room and started pouring water out of the pail. Sometimes he would be picking up his mobile phone, dialled numbers and started talking to another person. Unsure if he really made phone calls. Speech was unclear. Occasionally, he would be walking to the living room and switched on the television, appeared as if he was watching television. His mother noticed that for most episodes, his eyes were open with a glassy, staring appearance. There were two occasions where he would be crying and thrashing his pillow without reasons. He had 3 to 4 episodes per night with different activities for each episode. Pouring out water from a pail in the bathroom is the first and the most common activity every night. He would continue doing it until his mother dragged him to his bed. All episodes were aborted within 20 to 30 minutes. Any attempts to communicate with him during that period would fail. Patient had no recall of the events. So far, he has never injured himself and there were no history of urinary incontinence during those episodes.
On the following day, he would experience headache, dizziness, fatigue and sleepiness. He could not concentrate in school and his academic performance has deteriorated. As a result, his parents put pressure on him to perform better which makes him feel stressful. As he comes from a low income family, he has to help his parents selling cows milk in the neighbourhood after school.
His mother does not allow him to play with other kids.
He enjoyed going to school. He had normal childhood development and not known to have any medical illness.
His elder brother, 18 years old, had a fainting spell associated with urinary incontinence for the first time when he accompanied patient for CT scan.
There were no other family members with epilepsy or similar problem. Physical examination was normal and mental state examination was unremarkable.
Patient’s electroencephalogram (EEG) and non contrast CT brain were normal.
A diagnosis of somnambulism was made as per Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) and he was started on Tab Diazepam 5 mg on night. During the first 2 weeks of treatment, he woke up only once almost every night. 4 months later, diazepam was reduced to 2.5mg and gradually it was tapered off. The family was educated about the disorder and advised to reduce their pressure on the patient. Symptoms had not recurred up to one year following the stoppage of the medication.
Detailed and focused history of the event is important in diagnosing and managing this patient. Somnambulism, also known as sleep walking commonly seen in children with a peak incidence in children aged 11-12 years (Ackroyd G 2007). No difference in frequencies for both sexes (Sharma S., 2007). Duration for each episode varies. The main features (according to DSM-IV-TR) include repeated episodes of rising from bed during sleep and walking about occur. Usually it occurs during the first third of the major sleep episode. While sleepwalking, the patient has a blank staring face. During the episode, the patient is relatively unresponsive to the efforts of others to communicate with him. Upon awakening, the patient has amnesia regarding the episode.
In this case, nocturnal frontal lobe or complex partial seizures were important differentials as he presented with repeated stereotypical attacks every night and it was associated with fatigue and sleepiness on the following day (Ackroyd G. et al, 2007). Apart from that, his brother presented with first episode of query seizure at the clinic. At the time of writing his brother had defaulted medical follow-up but claimed that he has been well.
Confusional arousals i.e. crying and thrashing his pillow without reasons as seen in this patient, is also part of somnambulism (Ackroyd G. et al, 2007). The ongoing stress in which he needs to improve his academic performance, unable to play with other kids but has to sell cows milk after school, coupled with an unsupportive mother could have been the perpetuating factor for the disorder (Ackroyd G. et al, 2007).
There are no diagnostic investigations for this disorder. Conditions that need to be ruled out include thyrotoxicosis, epilepsy and space occupying lesion especially in patients with adult onset somnambulism (Vgonthas AN. et al, 1999). Differentiating an epileptic from a parasomniac attack based on EEG may not be straightforward especially when the epileptic focus is located in the deep frontal regions (Provini F. et al, 1999). There were several isolated reports documented epileptic abnormalities in patients with attacks resembling sleep terrors or sleep walking (Provini F. et al, 1999).
Non pharmacological approach include reassurance, relaxation therapy, avoid any kind of stimuli (auditory or visual) prior to bedtime and make sure that the environment is safe in order to avoid injury during an episode (Ackroyd G. et al, 2007) Pharmacological intervention is necessary when the disorder has caused excessive daytime sleepiness and impaired function as in this patient. Choices of medication include benzodiazepines, tricyclic antidepressants and selective serotonin reuptake inhibitors (Ackroyd G. et al, 2007).
Possible complications include accidental injury and overeating if food is taken during the episode (Sharma S., 2007). The prognosis is generally excellent for childhood onset and poorer for adult onset (Sharma S., 2007).
Somnambulism is relatively common among children and secondary causes must be ruled out. Nocturnal frontal lobe epilepsy is an important differential for this disorder.
1. Ackroyd G, D’Cruz OF. (2007) Somnambulism (Sleepwalking). www.emedicine.com/neuro/topic638.htm
2. American Psychiatric Association: Diagnostic and Statistical Manual, Fourth Edition, Text Revision. Washington, DC, American Psychiatric Association, 2000.
3. Provini F, Plazzi G, Tinuper P et al. (1999) Nocturnal frontal lobe epilepsy: A clinical and polygraphic overview of 100 consecutive cases. Brain. Vol 122: 1017-1032.
4. Sharma S. (2007) Parasomnias.
5. Vgonthas AN, Kales A. (1999) Sleep and Its Disorders. Annual Review of Medicine. Vol 50: 387-401.
Copyright Priory Lodge Education Limited 2010
First Published February 2010