Investigations
1st investigations to order
clinical examination
Test
Most parasomnias in children can be diagnosed on the basis of the history alone.
Result
typical history and normal physical examination
polysomnography (rapid eye movement sleep behaviour disorder)
Test
Rapid eye movement sleep behaviour disorder (RBD) is extremely rare in children and adolescents. If the clinical features suggest the possibility of RBD, polysomnography is performed to confirm the diagnosis.[54]
Result
Electromyogram (EMG): evidence of increased tone augmentation during rapid eye movement (REM) sleep; video: abnormal behaviour documented (e.g., shouting, swearing, kicking, punching)
Investigations to consider
polysomnography (confusional arousals)
Test
Should be ordered only if there is some uncertainty about the history or physical examination, or if the episodes are stereotypical, very frequent, or suspected to be occurring in association with another comorbid sleep disorder, such as sleep apnoea.
However, not required for the diagnosis of confusional disorder.
Result
Electroencephalogram (EEG) during episodes: arousals from slow-wave sleep may show brief episodes of delta activity, stage-1 theta patterns, repeated microsleeps, or a diffuse and poorly reactive alpha rhythm
polysomnography (sleepwalking)
Test
Can be helpful if the differential diagnosis includes sleepwalking precipitated by sleep-disordered breathing (e.g., obstructive sleep apnoea), other parasomnias causing sleepwalking, or rapid eye movement sleep behaviour disorder (RBD) mimicking sleepwalking.
However, not required for diagnosis of sleepwalking.
Result
Electroencephalogram (EEG): arousal from slow-wave sleep; video recording: may show aimless ambulation occurring during sleep and often preceded by sitting up in bed
polysomnography (sleep terrors)
Test
Can be helpful if the differential diagnosis includes sleep terrors precipitated by sleep-disordered breathing and other parasomnias causing sleep terrors.
However, not required for diagnosis of sleep terrors.
Result
Electroencephalogram (EEG): arousal from slow-wave sleep; video recording: demonstrates patient appearing fearful, with agitation and apparent confusion
polysomnography (nightmare disorder)
Test
Not required unless nightmare disorder needs to be differentiated from other parasomnias and this is proving difficult to do from history alone.
Result
Electroencephalogram (EEG): normal; or child awakens from rapid eye movement (REM) sleep and describes a distressing dream; may see evidence of another primary sleep disorder
polysomnography (all other parasomnias)
Test
Performed only if the diagnosis is not clear or the history has atypical features, or if a primary sleep disorder is suspected.
Result
normal; or evidence of other primary sleep disorder may be detected
polysomnography with expanded electroencephalogram (EEG) video recording
Test
The expanded test is performed if the episodes are stereotypical or repetitive, occur during the day, occur frequently (minimum of 1 event per week), or have not responded to medication trials, and the history is suggestive of potentially epileptic events.
Correlation of the clinical and polysomnographic analysis just prior to, during, and following an event of interest can be very helpful in differentiating nocturnal seizures from parasomnias.[56]
Result
non-epileptiform recording
urine drug screen
Test
May be considered in older children if illicit drug use is a possibility.
Result
no substances detected
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