Sleep Disorders

Narcolepsy

Clinical Characteristics
Narcolepsy is a malfunction of the sleep/wake regulating system. It is a rare genetic condition, due to a deficiency in hypocretin (a neuropeptide) whose symptoms typically emerge in adolescence. Its most common manifestation is an irresistible tendency to fall asleep, even in unlikely circumstances such as in the middle of a conversation or at a meal. These sleep attacks are brief periods of sleep during the person’s normal waking.23(p38) The five most common narcolepsy symptoms are Cataplexy,* Hypnagogic hallucinations,* Excessive daytime sleepiness,*Sleep paralysis,* and Sleep disruption (CHESS). Of these, only cataplexy is specific for narcolepsy. The others are common in sleep disruption from any cause. Secondary narcolepsy is generally caused by other medical conditions, such as inherited conditions, traumatic brain injury, and tumor. Some cases of secondary narcolepsy may also involve abnormality of hypocretin function.

For the LEO with narcolepsy, excessive daytime sleepiness is associated with the risk of decreased situational awareness, impairment of executive functioning and reduced vigilance. Cataplexy results in sudden incapacitation.

Diagnostic Criteria
Narcolepsy can be diagnosed by a thorough clinical history and/or clearly documented cataplexy, which is pathognomonic for the disease. Narcolepsy without cataplexy is uncommon and probably represents only 10-15% of patients with narcolepsy.29 Cataplexy spells can start up to 30 years after onset of narcolepsy, although in most cases, cataplexy first occurs within several years of onset of excessive daytime sleepiness. A nocturnal polysomnogram and a multiple sleep latency test (MSLT) are currently recommended to clarify the diagnosis of narcolepsy and to rule out more common sleep disorders.

Treatment of Narcolepsy
Alerting medications such as modafinil, armodafinil, methylphenidate, and dextroamphetamine have been used to treat the excessive daytime sleepiness caused by narcolepsy. Gamma Hydroxy Butyrate (GHB) has been shown in double-blinded controlled studies to substantially reduce the frequency of cataplexy. However, medications are merely tools to decrease sleepiness and frequency of cataplexy, and will not prevent their occurrence.30

LEO-Specific Clinical Studies and Reports
None identified.

Fitness-for-Duty Criteria
The unpredictable nature of narcolepsy with cataplexy may profoundly affect the LEO’s vigilance, situational awareness, executive functioning, and ability to maintain weapon control. Therefore, the incumbent LEO or applicant with confirmed narcolepsy with cataplexy is at risk of sudden incapacitation, and should be subject to appropriate work restrictions. For the incumbent LEO or applicant with confirmed narcolepsy without cataplexy, it is impossible to predict exactly when or if an initial episode of cataplexy will occur.