Medications, periodic limb movement

Insomnia secondary to a general medical condition, especially with pain- or sleep-disordered breathing Circadian rhythm disturbance Periodic limb movement disorder Restless legs syndrome... 

Sleepiness is a primary symptom of narcolepsy, often preceding the onset of the other well-known symptoms of the disease, namely cataplexy, sleep paralysis, and hypnagogic hallucinations (44). Evaluation of the MSLT of narcoleptic patients has demonstrated a short sleep latency (<5 min) and multiple sleep-onset REM periods (SOREMPs). The more specific finding in the MSLT of narcoleptic patients is more than 2 SOREMPs, shown to reach a specificity of 99% by Amira et al. (45), which further increased to 99.2% if 3 SOREMPs were recorded (46). On the other hand, more than one SOREMP can occur in nonnarcoleptic patients, such as those with sleep apnea, sleep deprivation, depression, periodic limb movements, circadian rhythm disruption, or withdrawal from REM-suppressing medications (5,47). Thus, the findings of the MSLT, which is always performed for suspected narcoleptic patients, must be interpreted in view of the clinical history and nocturnal PSG. 

The effective management of insomnia begins with recognition and adequate assessment. Family doctors and other health care providers should routinely enquire about sleep habits as a component of overall health assessment. Identification and treatment of primary psychiatric disorders, medical conditions, circadian disorders, or specific physiological sleep disorders, such as sleep apnea and periodic limb movement disorder, are essential steps in the management of insomnia [8],... 

A sleep disorder that is not endogenous or due to a medical condition or substance-related condition is categorized as not otherwise specified. Restless leg syndrome and periodic limb movements are two sleep disturbances that do not meet criteria for any of the other sleep disorders. 

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