Uncontrollable daytime sleeping

Maxwell Adeyemi

HAVE YOU sat next to or worked with someone who habitually falls asleep on the job and in every situation you see them they tend to nod off or snooze off with relative ease? They may be suffering from narcolepsy.

Narcolepsy is a neurological disorder that affects the control of sleep and wakefulness. People with narcolepsy experience excessive daytime sleepiness and intermittent, uncontrollable episodes of falling asleep during the daytime. These sudden sleep attacks may occur during any type of activity at any time of the day.

In a typical sleep cycle, we initially enter the early stages of sleep followed by deeper sleep stages and ultimately (after about 90 minutes) rapid eye movement (REM) sleep. For people suffering from narcolepsy, rapid eye movement sleep occurs almost immediately in the sleep cycle, as well as periodically during the waking hours. It is in the REM phase of sleep that we can experience dreams and muscle paralysis – which explains some of the symptoms of narcolepsy.

Symptoms of narcolepsy

People with narcolepsy experience various types of daytime and night-time sleep problems that are associated with REM sleep disturbances that tend to begin subtly and may change dramatically over time. The most common major symptom, other than excessive daytime sleepiness, is cataplexy, which occurs in about 70 per cent of all people with narcolepsy. Sleep paralysis and hallucinations are somewhat less common.

Excessive

daytime sleepiness

Excessive daytime sleepiness, the symptom most consistently experienced by almost all individuals with narcolepsy, is usually the first to become clinically apparent. This interferes with normal activities on a daily basis, whether or not individuals had sufficient sleep at night.

It is a persistent sense of mental cloudiness, a lack of energy, a depressed mood, or extreme exhaustion. Some people experience memory lapses, and many have great difficulty maintaining their concentration while at school, work, or home.

As many as 40 per cent of people with narcolepsy are prone to automatic behaviour during such “micro sleeps.” Automatic behaviour involves performing a task during a short period of sleep but without any apparent interruption.

During these episodes, people are usually engaged in habitual, essentially "second nature" activities such as taking notes in class, typing, or driving. They cannot recall their actions, and their performance is almost always impaired.

Their handwriting may, for example, degenerate into an illegible scrawl, or they may store items in bizarre locations and then forget where they placed them. If an episode occurs while driving, individuals may get lost or have an accident.

Loss of muscle tone (Cataplexy)

Cataplexy is a sudden loss of muscle tone while the person is awake that leads to feelings of weakness and a loss of voluntary muscle control. Attacks can occur at any time during the waking period, with individuals usually experiencing their first episodes several weeks or months after the onset of excessive daytime sleepiness. But in about ten per cent of all cases, cataplexy is the first symptom to appear and can be misdiagnosed as a seizure disorder.

Cataplectic attacks vary in duration and severity. The loss of muscle tone can be barely perceptible, involving no more than a momentary sense of slight weakness in a limited number of muscles, such as mild drooping of the eyelids.

Sleep paralysis

The temporary inability to move or speak while falling asleep or waking is similar to rapid eye movement-induced inhibitions of voluntary muscle activity. This natural inhibition usually goes unnoticed by people who experience normal sleep because it occurs only when they are fully asleep and entering the REM stage at the appropriate time in the sleep cycle. The attacks usually last a few seconds or minutes.

Hallucinations

Hallucinations can accompany sleep paralysis and occur when people are falling asleep, waking, or during sleep. Referred to as hypnagogic hallucinations when occurring during sleep onset and as hypnopompic hallucinations when occurring during waking, these images are unusually vivid, seem real, and can be frightening.  Most often, the content is primarily visual, but any of the other senses can be involved.

Disrupted nocturnal sleep

While individuals with narcolepsy have no difficulties falling asleep at night, most experience difficulties staying asleep. Sleep may be disrupted by insomnia, vivid dreaming, sleep talking, acting out while dreaming, and periodic leg movements.

Obesity

After developing narcolepsy, many individuals suddenly gain weight, a side effect that can be prevented by active treatment

Diagnosis

A physical exam and detailed medical history are essential for proper diagnosis of narcolepsy. However, none of the major symptoms is exclusive to narcolepsy.

Several specialised tests, which can be performed in a sleep disorders clinic or sleep lab, usually are required before a diagnosis can be established.

Two tests that are considered essential in confirming a diagnosis of narcolepsy are the polysomnogram (PSG) and the multiple sleep latency test (MSLT).

The PSG is an overnight test that takes continuous multiple measurements while a patient is asleep to document abnormalities in the sleep cycle.

The MSLT is performed during the day to measure a person's tendency to fall asleep and to determine whether isolated elements of REM sleep intrude at inappropriate times during the waking hours.

Treatment

Although there is no cure for narcolepsy, the most disabling symptoms of the disorder (excessive daytime sleepiness and symptoms of abnormal REM sleep, such as cataplexy) can be controlled in most people with drug treatment.

Sleepiness is treated with amphetamine-like stimulants, while the symptoms of abnormal rapid eye movement sleep are treated with antidepressant drugs.

Lifestyle adjustments such as avoiding caffeine, alcohol, nicotine, and heavy meals, regulating sleep schedules, scheduling daytime naps (ten-15 minutes in length), and establishing a normal exercise and meal schedule may also help to reduce symptoms.

Referral to a sleep centre or clinic can also be beneficial for long-time therapy and follow-up care.

Contact Dr Maxwell on 3631807 or 7575411