Narcolepsy

Abstract

Narcolepsy is a neurological condition with a prevalence of up to 1 per 1,000 that is characterized by irresistible bouts of sleep. Associated features include the pathological manifestations of rapid-eye-movement (REM) sleep: cataplexy, sleep paralysis, hypnagogic hallucinations, and abnormal sleep-onset REM periods and disturbed nocturnal sleep. The condition is strongly associated with the HLA-DR2 and DQw1 phenotype. The phenomenology of narcolepsy is discussed, and diagnostic procedures are reviewed. Treatment modalities involving central nervous system stimulants for somnolence and tricyclic drugs for REM-sleep abnormalities are discussed. Sleep laboratory studies on the treatment efficacy of methylphenidate, pemoline, dextroamphetamine, protriptyline, and viloxazine are presented. Data suggest that: (1) methylphenidate and dextroamphetamine objectively improve somnolence; (2) pemoline, at doses up to 112.5 mg, is less effective in controlling somnolence but may improve certain aspects of performance; and (3) protriptyline and viloxazine are effective anticataplectic agents that produce little improvement in somnolence.

FIG. 1

Opposite page: Family tree. The black symbols indicate clinical cases of narcolepsy, the half-black, half-white symbols indicate excessive daytime sleepiness, the white symbols indicate healthy subjects, and “a” indicates HLA-DR2-positive cases. The association between clinical narcolepsy and HLA-DR2 is seen in the cases of RC, Sr., RC, Jr., RS, and RW. The results of the nocturnal polysomnographic recording and multiple sleep latency testing are also shown. MSLT, mean sleep latency, in minutes: REMs, number of REM sleep episodes on MSLT; REML, latency from first sleep to REM sleep, in minutes, on nocturnal polysomnographic recording (NPSG): and REM %, percent of REM sleep during NPSG. Above: Explanations for the HLA codings. An asterisk indicates the most probable antigens or haplotype, an X indicates a true blank, and ^^ indicates retyping using new cells-reg isolation.

FIG. 1

Opposite page: Family tree. The black symbols indicate clinical cases of narcolepsy, the half-black, half-white symbols indicate excessive daytime sleepiness, the white symbols indicate healthy subjects, and “a” indicates HLA-DR2-positive cases. The association between clinical narcolepsy and HLA-DR2 is seen in the cases of RC, Sr., RC, Jr., RS, and RW. The results of the nocturnal polysomnographic recording and multiple sleep latency testing are also shown. MSLT, mean sleep latency, in minutes: REMs, number of REM sleep episodes on MSLT; REML, latency from first sleep to REM sleep, in minutes, on nocturnal polysomnographic recording (NPSG): and REM %, percent of REM sleep during NPSG. Above: Explanations for the HLA codings. An asterisk indicates the most probable antigens or haplotype, an X indicates a true blank, and ^^ indicates retyping using new cells-reg isolation.