Can a small child have cataplexy without narcolepsy?

August 7, 2008 9:27 AM

Is it possible for a small child to have cataplexy without narcolepsy?

I'm not usually one of those worrying-about-whether-my-child-has-the-disease-of-the-week type of parents. I think I'm about as laid back and easy-going as they get. But today's BBC story about cataplexy has me wondering about this.

Here are my data points in reverse chronological order:

• My four-year-old son collapses to the floor when he's tickled in a certain spot. He giggles like a maniac before and after falling and does not appear to be in distress. He just completely loses the ability to keep himself upright (sorta like one of those toys where you push the bottom of the base and all the character's joints go loose).
• Last autumn, he had a bad fall off a bed, resulting in unconsciousness and a concussion. He was sitting on the edge of the bed and then suddenly flopped to the ground, head first without putting his hands out, continuing over to flop down on his back. This happened shortly after waking up early, and the doctors at the time said he probably just fell asleep again.
• When he was a crawling baby, he frequently did spectacular faceplants when all his limbs would suddenly go out from under him. He was not otherwise wobbly -- he was a very adept, sturdy, and fast crawler. I am in a position to observe many crawling babies and I haven't seen any others fall the way he would. At the time, I wondered if he was having some sort of mini-seizure, but once he started walking I forgot about it.
• He had a blood transfusion in-utero at about 26 weeks gestation to fight severe (near-fatal) anemia due to parvovirus infection (fifth disease). The pregnancy went fine after that and, though there was concern about possible brain damage, he had extensive follow-up over the first four years of his life and no problems were ever detected.

And that's about it. He's a bright, funny, creative kid. Nobody who knows him would think he's got any neurological issues (including those neonatal follow-up doctors who were looking for neurological issues).

Anonymous because I expect he's not going to want the tickling thing known if it still happens when he's older. Email [e-mail]

posted by anonymous to Health & Fitness (6 answers total)

It's possible. Whether he maintains consciousness during these attacks is important.

I don't have my sleep medicine text here now, but these are excerpts from a highly regarded online medical textbook:

"EPIDEMIOLOGY — Narcolepsy with cataplexy is estimated to have a prevalence of 25 to 50 per 100,000 people and an incidence of 0.74 per 100,000 person-years. It is equally common in men and women. The disease typically begins in the teens and early twenties, but can occur as early as five years of age or after 40 years of age. The symptoms may worsen during the first few years and then persist for life."

"CLINICAL FEATURES — Narcolepsy can be viewed as a disorder of sleep-wake state control in which elements of sleep intrude into wakefulness, and elements of wakefulness intrude into sleep. The net effect is daytime sleepiness with varying amounts of hypnagogic hallucinations, sleep paralysis, and cataplexy. Only about one-third of patients will have all four of these classical symptoms; thus, the diagnosis of narcolepsy should be considered even in patients with sleepiness alone."

"Cataplexy — Cataplexy is bilateral muscle weakness leading to partial or complete collapse. True cataplexy is almost always triggered by strong emotions such as laughter, joking, excitement, or anger. The paralysis typically lasts less than two minutes, and consciousness is intact. Cataplexy develops within three to five years of the onset of sleepiness in 60 percent of people with narcolepsy."
posted by neuron at 10:17 AM on August 7, 2008

Has he had a complete neurological work up done by a neurologist rather than a pediatrician? When you say 'those neo-natal follow up doctors' what was their specialty? I don't think with the details you've given it can be narrowed down to any one thing.
posted by spicynuts at 10:26 AM on August 7, 2008

Narcolepsy is suspected to be autoimmune in many cases, involving the death of cells that produce orexin / hypocretin (same peptide hormone, two names for it) in the hypothalamus. Brain damage might cause a similar cell death. The peptide isn't needed to maintain wakefulness but is important in stabilizing sleep/wake cycles. Without a functional orexin system, the brain can flip between sleep and wakefulness at random, but often through common triggers like food availability or laughing.

The short answer is that only a clinical workup can tell you whether your son is narcoleptic. You might be asked for permission to sample blood or CSF to test for the presence of orexin. A check at a sleep clinic will also likely be in order, to see whether sleep cycles are disrupted (narcolepsy doesn't just cause sleep to intrude into wakefulness; wakefulness also interrupts sleep cycles).

The best thing you can do is talk to a doc. There are other problems that go along with narcolepsy - for example weight gain is a common comorbidity. Knowing what he may have to deal with will help you deal. Good news is that there are safe, widely used treatments (Modafinil for example activates orexin cells, and has been used to decrease narcolepsy symptoms so long as some cells remain functional).

Note: I'm not a sleep researcher per se; my dissertation work dealt with orexin and circadian activity, and I am now looking into orexin and obesity, so I've been around the narcolepsy literature enough to feel I can give some solid advice. As always I may be a PhD but I'm not your PhD, etc, etc.
posted by caution live frogs at 10:42 AM on August 7, 2008 [1 favorite]

I've had similar issues with losing consciousness that was eventually identified as syncope.
posted by boo_radley at 12:07 PM on August 7, 2008

The tickling thing used to happen to me when I was a child. Never any narcolepsy either. I eventually grew out of it though, so your son may too.
posted by fishmasta at 8:15 PM on August 7, 2008

I don't buy this being cataplexy. Cataplexy without narcolepsy generally suggests a psychiatric disorder, which is not likely in the very young. There are plenty of other reasons for sudden losses of muscle tone.

I can't tell from here whether your kid needs a neurologist or not.
posted by ikkyu2 at 11:27 PM on August 7, 2008