Study objectives: The purpose is to report the results of an effort to diagnose children with narcolepsy in a pediatric referral clinic.
Design: Between September 1998 and December 1999, a program was implemented to emphasize recognition of childhood narcolepsy. Patients underwent brain computed tomography (CT) scan and magnetic resonance imaging (MRI) testing. All children received a MSLT test following a routine night's sleep, and serological HLA typing for HLA DR2. Three who reported occasional snoring also underwent nocturnal PSG prior to the MSLT.
Setting: N/A.
Patients or participants: N/A.
Interventions: N/A.
Measurements and results: 29 (21 male, 8 female) children were identified with sleepiness and cataplexy. There was no evidence for brain functional or structural disease or for drug use. Sleep paralysis was elicited in 41%; hypnagogic hallucinations, in 59%. Psychosocial problems including emotional irritability and social isolation were present in 93% of the patients. Mean sleep latency on MSLT was 2.0+/-1.3 minutes; sleep-onset rapid eye movement (SOREM) occurred during 2/5 naps in 28 of 29 patients and 3/5 in 26/29 patients. The average number and latency of SOREM episodes were 4.2+/-0.9 episodes and 4.0+/-1.7 minutes, respectively. In those with snoring, a nocturnal PSG did not disclose sleep apneas/hypopneas. All patients but one were HLA DR2 positive. The estimated clinic incidence was 0.04%.
Conclusions: A program for recognition in a referral neurology clinic combined with an availability of the MSLT and HLA testing resulted in the new identification in North China of a number of children with narcolepsy syndromes.