Cataplexy

Cataplexy, narcolepsy, catalepsy, sleep paralysis, cataplexia, cienciologia

Cataplexy is a sudden loss of muscle tone that occurs in people with narcolepsy. Cataplexy causes people to suddenly fall down or go weak in the knees at random times—often when being emotional or laughing. As you might imagine, it is not a symptom that can easily be tolerated—people who have it need treatment.

What is the cure for cataplexy? At this time we don't have a cure, but it is possible that we will soon be able to replace the neuropeptide hypocretin-1 that is missing in these patients. That would be close to a cure, but for now, we have three classes of medications that work pretty well. They are also used to decrease dreaming and hallucinations which sometimes occur in patients with narcolepsy.

The anti-depressants in the tricyclic family are very effective for narcolepsy. Those prescribed the most are imipramine, amitriptyline (Elavil), protriptyline (Vivactyl) and clomipramine. Protriptyline is somewhat of a stimulant, so it can be taken in the day, whereas the others are sedating so they are taken at bedtime. The benefit on cataplexy lasts through the day. The doses used are lower than used for depression, for example 25 to 75 mg of imipramine, amitriptyline, and clomipramine. Side effects are similar for all of them, and are "anti-cholinergic," which means dry mouth, slowness of urination, weight gain and a feeling of grogginess. These side effects are usually mild and go away, especially in younger people.

A second family of medications that work for cataplexy are the selective serotonin re-uptake inhibitors such as fluoxetine (Prozac), paroxetine (Paxil) and venlafexine (Effexor). This more modern family of antidepressants is probably used more often for people with cataplexy because of fewer side effects in general. Nonetheless, these medications can cause weight gain and some people do not like the mental feeling that they can produce. They are used in the same doses for cataplexy that are used for depression, so they can effectively treat both.
Lastly, a newer medication has been approved specifically for cataplexy. This agent is not an antidepressant, and is used only in narcoleptics. Xyrem

is a liquid that is taken at bedtime and again in the middle of the night. It is very sedating, but it helps the cataplexy the next day even though it is out of the system by then. I have several patients who take it because they do not tolerate the antidepressants, but some people do not take it due to expense issues or the hassle of taking it in the night. Because it is so sedating, some older patients do not tolerate it. It seems to work through the GABA system in the brain, whereas the antidepressants work through the noradrenergic system.

In healthy people, both sleepiness and vigilance show a relationship with core body temperature and skin temperature. When core body temperature is high during the daytime, skin temperature is low, which translates into optimal vigilance. Conversely, when core body temperature is low at night time, skin temperature is high, which correlates to optimal sleep.

Among those suffering from narcolepsy, however, direct manipulations of their skin and core body temperatures affect their vigilance and sleepiness, according to a study published in the February 1 issue of the journal SLEEP.

The study, authored by Rolf Fronczek, of the Netherlands Institute for Neuroscience in Amsterdam, and Leiden University Medical Center in The Netherlands, focused on eight patients who were diagnosed with narcolepsy with cataplexy and suffered from excessive daytime sleepiness. The subjects’ vigilance was measured using the Psychomotor Vigilance Task, and their sleepiness was assessed with the Maintenance of Wakefulness Test. Meanwhile, their skin temperature was mildly manipulated using a thermosuit, while their core body temperature was manipulated using hot or cold food and drinks.

According to the results, patients were better able to maintain vigilance when core body temperature was increased than when it was lowered, indicating that vigilance in narcolepsy can be altered simply by altering the temperature of food and drinks. Also, the ability to maintain wakefulness was better when skin temperature was lowered than when it was increased. Therefore, the process of falling asleep in narcoleptic subjects was able to be influenced by gently cooling or warming their hands and feet.

“Patients with narcolepsy lack a specific neurotransmitter in their brains. This neurotransmitter is responsible for the regulation of the sleep/wake rhythm. That is why narcoleptic patients fall asleep during the day, but have problems sleeping during the night,” said Fronczek. “Sleep and skin temperature are tightly related, as everybody who ever tried to go to bed with cold feet will know. Earlier researchers discovered that in healthy people, the temperature of the distal skin – hands and feet – not only increases just before falling asleep, but also influences sleep itself. Warm hands and feet thus promote sleep. Our research shows that, surprisingly, the temperature of the hands and feet of people with narcolepsy is on a high level throughout the day, a level that is normally only seen in healthy people just before falling asleep. We normalized this abnormal pattern of skin temperature using a specially designed thermosuit that can differentially manipulate the distal en proximal skin temperature with warm or cold water. In this way, we were able to decrease daytime sleepiness and improve vigilance. This could lead to new therapeutical applications that can help to alleviate some of the symptoms of narcolepsy.”

Narcolepsy is a sleep disorder that causes people to fall asleep uncontrollably during the day. It also includes features of dreaming that occur while awake. Other common symptoms include sleep paralysis, hallucinations and cataplexy. About one out of every 2,000 people is known to have narcolepsy. There does seem to be a genetic link to it. It is very rare for more than two people in the same family to have this sleep disorder. It affects the same number of men and women.

It is recommended that adults get between seven and eight hours of nightly sleep.

The American Academy of Sleep Medicine (AASM) offers the following tips on how to get a good night’s sleep:

* Follow a consistent bedtime routine.
* Establish a relaxing setting at bedtime.
* Get a full night’s sleep every night.
* Avoid foods or drinks that contain caffeine, as well as any medicine that has a stimulant, prior to bedtime.
* Do not bring your worries to bed with you.
* Do not go to bed hungry, but don’t eat a big meal before bedtime either.
* Avoid any rigorous exercise within six hours of your bedtime.
* Make your bedroom quiet, dark and a little bit cool.
* Get up at the same time every morning.

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