What is normal sleep latency:-: (A) 20 minutes, (B) 120 minutes, (C) 60 minutes, (D) 90 minutes
Answer is A. Normal Sleep latency is about 20 - 40 minutes Any sleep latency less than 8 minutes is abnormal and quite characteristic of Narcolepsy. REM latency is different from sleep latency, as it is the time taken to enter the first REM phase during sleep. This is about 90 minutes.