Comparative analysis of multiple sleep latency tests (MSLT) parameters and occurrence of dreaming in patients with daytime sleepiness of narcoleptic and non-narcoleptic origin.

OBJECTIVE: To compare MSLT parameters in two groups of patients with daytime sleepiness, correlated to the occurrence and onset of dreams. METHOD: Patients were submitted to the MSLT between January/1999 and June/2002. Sleep onset latency, REM sleep latency and total sleep time were determined. The occurrence of dreams was inquired following each MSLT series. Patients were classified as narcoleptic (N) or non-narcoleptic (NN). RESULTS: Thirty patients were studied, 12 were classified as narcoleptics (N group; 40%), while the remaining 18 as non-narcoleptic (NN group; 60%). Thirty MSLT were performed, resulting in 146 series. Sleep was detected in 126 series (86%) and dreams in 56 series (44.44%). Mean sleep time in the N group was 16.0+/-6.3 min, while 10.5+/-7.5 min in the NN group (p<0.0001). Mean sleep latency was 2.0+/-2.2 min and 7.2+/-6.0 min in the N and NN group, respectively (p<0.001). Mean REM sleep latency in the N group was 3.2+/-3.1min and 6.9+/-3.7 min in the NN group (p=0.021). Dreams occurred in 56.9% of the N group series and 28.4% in that of the NN group (p=0.0009). Dream frequency was detected in 29.8% and 75% of the NREM series of the N and NN groups, respectively (p=0.0001). CONCLUSION: Patients from the N group, compared to the NN group, slept longer and earlier, demonstrated a shorter REM sleep onset and greater dream frequency. NN patients had a greater dream frequency in NREM series. Thus, the occurrence of dreams during NREM in the MSLT may contribute to differentially diagnose narcolepsy and daytime sleepiness.

Comparative analysis of multiple sleep latency tests (MSLT) parameters and occurrence of dreaming in patients with daytime sleepiness of narcoleptic and non-narcoleptic origin / Estudo comparativo de parâmetros de testes de latências múltiplas do sono (TLMS) e ocorrência de sonhos em pacientes hipersones narcolépticos e não-narcolépticos

OBJECTIVE: To compare MSLT parameters in two groups of patients with daytime sleepiness, correlated to the occurrence and onset of dreams. METHOD: Patients were submitted to the MSLT between January/1999 and June/2002. Sleep onset latency, REM sleep latency and total sleep time were determined. The occurrence of dreams was inquired following each MSLT series. Patients were classified as narcoleptic (N) or non-narcoleptic (NN). RESULTS: Thirty patients were studied, 12 were classified as narcoleptics (N group; 40 percent), while the remaining 18 as non-narcoleptic (NN group; 60 percent). Thirty MSLT were performed, resulting in 146 series. Sleep was detected in 126 series (86 percent) and dreams in 56 series (44.44 percent). Mean sleep time in the N group was 16.0±6.3 min, while 10.5±7.5 min in the NN group (p<0.0001). Mean sleep latency was 2.0±2.2 min and 7.2±6.0 min in the N and NN group, respectively (p<0.001). Mean REM sleep latency in the N group was 3.2±3.1min and 6.9±3.7 min in the NN group (p=0.021). Dreams occurred in 56.9 percent of the N group series and 28.4 percent in that of the NN group (p=0.0009). Dream frequency was detected in 29.8 percent and 75 percent of the NREM series of the N and NN groups, respectively (p=0.0001). CONCLUSION: Patients from the N group, compared to the NN group, slept longer and earlier, demonstrated a shorter REM sleep onset and greater dream frequency. NN patients had a greater dream frequency in NREM series. Thus, the occurrence of dreams during NREM in the MSLT may contribute to differentially diagnose narcolepsy and daytime sleepiness.

OBJETIVO: Comparar variáveis do TLMS em dois grupos de pacientes hipersones e correlacionar presença e momento de ocorrência de sonhos. MÉTODO: Os pacientes foram submetidos a TLMS entre janeiro de 1999 e junho de 2002. Analisou-se a média das latências de sono, latências de sono REM e tempo total de sono. A presença de sonhos foi inquirida após cada série. Classificou-se os pacientes em narcolépticos (N) e não-narcolépticos (NN). RESULTADOS: Do total de 30 pacientes, 12 foram classificados no grupo N (40 por cento) e 18 no NN (60 por cento). Dos 30 TLMS foram obtidas 146 séries. Houve sono em126 (86 por cento) e sonho em 56 (44,44 por cento). O tempo médio de sono no grupo N foi 16,0±6,3min e no NN 10,5±7,5min (p<0,0001). A latência média de sono no grupo N foi 2,0±2,2min e no NN 7,2±6,0min (p<0,001). A latência média do sono REM no N foi 3,2±3,1min e no NN 6,9±3,7min (p=0,021). Houve sonhos em 56,9 por cento das séries do grupo N e 28,4 por cento do NN (p=0,0009). A freqüência de sonhos em séries NREM no N foi 29,8 por cento e no NN 75 por cento (p= 0,0001). CONCLUSÃO: Os pacientes do grupo N dormiram mais e mais rapidamente, apresentaram REM mais precocemente e maior freqüência de sonhos que os NN. Estes apresentaram maior freqüência de sonhos em séries NREM. A presença de sonhos em NREM no TLMS pode contribuir no diagnóstico diferencial entre narcolepsia e hipersonia diurna.