Narcoleptic patients suffer episodes of unwanted or unintended sleep. While these patients often experience excessive sleepiness and bouts of involuntary sleep, often called sleep attacks, they should be distinguished from the symptom of prolonged sleepiness. Narcolepsy is a heritable central nervous system disorder that is a common cause of sleep disturbance. It is the second most common cause of disabling daytime sleepiness after sleep apnea.
Patients with narcolepsy face various psychosocial and work-related problems throughout their lives. As a result, patients with this disorder often experience progressive difficulty in meeting their economic and social responsibilities. While the symptoms of narcolepsy do not tend to worsen with age, they do interact negatively with other age-related problems and medical conditions. For example, conditions such as chronic obstructive pulmonary disease (COPD), with its well-known capacity to disrupt sleep, can produce sleep deprivation and exacerbate the symptoms of narcolepsy.
Patients with narcolepsy have the additional burden of coping with misperceptions about the causes and the involuntary nature of the symptoms. Common misconceptions, even among healthcare providers, include beliefs that sleep attacks and cataplexy are manifestations of denial and avoidance, and that symptoms can be controlled with behavioral or psychotherapeutic techniques.
While there is no credible evidence to support such ideas, there is a role for psychologic intervention in the management of patients with narcolepsy. Such patients often benefit from participation in professionally supervised support groups that focus on coping skills and identification of community resources.
Non-hereditary cases of narcolepsy are most common in humans, but the narcoleptic trait is also heritable. The risk for narcolepsy among the children of a patient with narcolepsy is several orders of magnitude greater than the risk observed in the general population.
Common symptoms include:
Two distinct types of paralysis may occur:
REM sleep may appear in two or more naps in patients without narcolepsy if:
Patients with narcolepsy cannot perform psychomotor tasks or maintain alertness as well as normal controls, even when treated with psychostimulants and REM-sleep-suppressing drugs. Review of multiple studies indicates that patients receiving the maximum recommended doses of stimulant medications rarely reach above 70 to 80% of normal control levels on tests of performance and alertness. Many authorities recommend a goal of obtaining maximum alertness at selected times of the day, for example during work or school hours and while driving, and using scheduled naps to help maintain alertness. Others recommend a goal of maximal or "normal" alertness throughout conventional waking hours. Unfortunately, most data indicate that although daytime sleep episodes can be reduced in most cases, they cannot be completely abolished in all patients.
In the 1970s, GHB was used to treat sleep disorders, and some interest in this use continues. Some doctors feel it is the most reliable medication for inducing sleep that exists. It is thought to induce rapid eye movement sleep, decreasing symptoms of narcolepsy. Many prominent doctors have been outspoken about the unnecessary legal restrictions placed on this naturally-occurring substance. Medical use in the treatment of narcolepsy is usually 50mg/kg per day.
Several independent investigators have reported beneficial effects by GHB against narcolepsy but only two double-blind studies have been published [Scrima et al, 1989 and 1990; Lammers et al., 1993]. Based on these two reports, there is little doubt that the drug is helpful to narcoleptic patients and several other independent investigators have confirmed the findings.
The most consistent and least controversial effects are improved cataplexy and improved nocturnal sleep disruption with GHB treatment [Scrima et al., 1990; Broughton and Mamelak, 1980: Bedard et al., 1990]. Further investigations would be needed to confirm a possible beneficial effect for daytime sleepiness. Importantly, GHB's anti-cataplectic effects are clearly mediated by a different mode of action when compared to those produced by antidepressant compounds. As such, patients who do not tolerate classical antidepressant treatment because of side-effects, tolerance or contraindications would not have any other choice if GHB were not available to them.