Dados do Trabalho

Título

Narcolepsy diagnostic difficulties: Case series experience at the Ambulatory Sleep Disorders Center (ASONO) of the Psychiatry Institute (IPq) – HCFMUSP

Introdução

Narcolepsy a sleep disorder classified as a Central Disorder of Hypersomnolence by the International Classification of Sleep Disorders and is characterized by excessive daytime sleepiness and signs of REM-sleep dissociation in addition to its association with hypocretin deficiency. It is not always easy to build a diagnostic hypothesis, since multiple nosological entities can overlap or go unnoticed, which makes difficult the diagnosis and adequate treatment of rare and serious diseases such as narcolepsy.

Objetivo

Show the difficulties in the diagnosis of narcolepsy in clinical practice.

Métodos

We describe 3 clinical cases referred to ASONO previously diagnosed as narcolepsy, due to sleep attacks during the day, associated with other clinical symptoms suggestive of the disease. The patients were submitted to a clinical investigation and the narcolepsy protocol was performed, with the use of actigraphy for 15 days, type 1 polysonography followed by Multiple Latency Sleep Test (MLST).

Resultados

After considering the clinical data and the results of the diagnostic tests, we observed some critical points. Case 1: the patient showed excessive daytime sleepiness (average sleep latency < 5 minutes, 2 SOREMPs), circadian rhythm disorder and psychiatric disease. Case 2: the patient showed excessive daytime sleepiness (average sleep latency 1,9 minutes, 4 SOREMPs), sleep deprivation, circadian rhythm disorder. Case 3: the patient showed excessive daytime sleepiness (average sleep latency 4,9 minutes, 2 SOREMPs), circadian rhythm disorder and psychiatric disease.

Conclusões

Despite the low sensitivity and specificity of the MLST is considered the gold standard for narcolepsy diagnosis, there are some important considerations. First it is necessary to establish a sleep routine preferably with consistent waking and sleep times. Second it is important to washout some medication like antidepressants and psychostimulants. Finally, there should be no sleep deprivation (confirmed by sleep logs or actigraphy for 15 days before the test). We suspected a misdiagnosis in the cases presented and they were revisited following the considerations above. Only one of the cases maintained the original diagnosis and this an alarming occurrence. Narcolepsy is a rare disease in Brazil and patients are submitted to several limitations in their daily lives besides the use of medication and psychological support. Following a protocol to adequately perform narcolepsy diagnosis is mandatory.

Palavras-chave

Narcolepsy; Sleepiness