Clinico-polysomnographic diagnostics of narcolepsy-cataplexy.
The introduction of polysomnography changed considerably our knowledge about narcolepsy. The aim of our study was to present the clinical picture and diagnostic criteria of narcolepsy based on our own research data. The study comprises 22 consecutive patients with a mean age of 39.8 years, SD = 16.4, age range 7-78 years. The following methods were used: neurological, physical and mental status examination, specially designed questionnaires, nocturnal polysomnography, MSLT. The following clinical manifestations were observed: excessive daytime sleepiness (EDS) in 95.45% of the cases, cataplexy attacks (CA) in 77.27%, hypnagogic hallucinations (HH)--in 77.27%, sleep paralysis (SP)--in 54.54% and subjectively disturbed nocturnal sleep--in 72.72%. The mean ages of occurrence of the respective symptoms were as follows: EDS--32.14 +/- 10.15 years, CA--28.70 +/- 11.70 years, HH--36.70 +/- 8.82 years, SP--35.53 +/- 15.50 years and for the disease as a whole--39.82 +/- 15.50 years. At MSLT the mean sleep latency was 165.91 +/- 16.37 seconds and the mean REM latency--207.96 +/- 14.09 seconds. During the nighttime sleep the mean sleep latency was less than 5 minutes and the mean REM latency--less than 7 minutes. The sleep structure showed: NREM sleep, stage 1,2--66.30 +/- 4.1%, stage 3,4--5.52 +/- 4.1%, REM sleep--25.65 +/- 2.3%. The clinical picture presented 4 symptoms in 31.81%, 3 symptoms--in 50.00%, 2 symptoms--in 9.09% and 1 symptom in 9.09% of the cases. 1. The onset of narcolepsy is at about 30 years of age. 2. The clinical picture of narcolepsy is characterized by 2 major symptoms--excessive daytime sleepiness, attacks of cataplexy and 3 minor symptoms--sleep paralysis, hypnagogic hallucinations and disturbed nighttime sleep which may be found in various combinations. 3. Nocturnal polysomnography demonstrates characteristic changes in sleep structure. 4. MSLT ascertains shorter sleep latency and sleep onset rapid eye movements periods (SOREMs) of less than 5 minutes. 5. The presence of one of the major symptoms and SOREMs is sufficient for confirming the diagnosis of narcolepsy.