We reported a case of a 24-year-old man who had frequent sleep attacks beginning 4 years after a
head trauma. He showed frequent episodes of
excessive daytime sleepiness and
cataplexy which were triggered by emotional excitement. He also complained of
sleep paralysis and
hypnagogic hallucination. An overnight polysomnography revealed the sleep onset REM stage as typically observed in narcoleptic patients. The HLA typing was negative for DR2 and DQw1. He was diagnosed as having
HLA-DR2 and DQw1 negative-post-traumatic
narcolepsy. Peroral
pemoline suppressed
excessive daytime sleepiness,
sleep paralysis and
hypnagogic hallucination with dramatic relief of cataplectic attacks by the addition of
imipramine. It has been reported that more than 90% of narcoleptic patients are
HLA-DR2 and-DQw1 positive. About 10% of the
narcolepsy patients were regarded as symptomatic due to
brain tumors,
cerebrovascular disorders,
head trauma,
multiple sclerosis,
encephalitis and so on, which mainly affect the brainstem or diencephalon. Thus far,
narcolepsy is considered to develop depending on both the genetic background including HLA types, and exogenous factors. According to reported cases with
narcolepsy, sporadic cases were
HLA-DR2 positive even more frequently than familial cases. To date, however, there have been only three previous reports of a symptomatic
narcolepsy patient without association of
HLA-DR2 and DQw1. In conclusion, the present report suggests that typical symptomatic
narcolepsy could be
HLA-DR2 or DQw1 negative.