knock knock. Who’s there? zzz..
When “weak at the knees” becomes more literal than it should.
To pursue a life filled with joyful emotions is not always the answer, especially for individuals with type I narcolepsy. Narcolepsy is a brain disorder that makes you fall asleep frequently and unexpectedly. Individuals with narcolepsy fall asleep without warning, no matter hard they try not to. This can be dangerous in several situations such as when driving, swimming or operating machinery. In addition, it can be debilitating in the workforce as well as in school. Narcolepsy occurs in both men and woman and can develop during the teen or adolescence years. It is defined as a daytime sleepiness syndrome that includes immediate and sudden sleep episodes, cataplexy (sudden and temporary physical collapse), as well as sleep paralysis. Individuals suffering from narcolepsy with cataplexy (a.k.a. Narcolepsy type I) tend to have temporary muscle weakness or paralysis when they are experiencing extreme -positive or negative- emotions. This means that if they heard a joke or exciting news they could suddenly fall asleep! In extreme cases, they could fall down immediately. Since cataplexy could be quite frustrating and most likely dangerous for those individuals, some tend to avoid having exciting or positive stimulations all together. Imagine not being able to enjoy those feelings that are the essence of human interaction and overall wellbeing.
As narcolepsy is the second most common cause of disability of daytime sleepiness and since it leads to a low quality of life, it is important to investigate it in order to provide a more effective treatment. Until now there is no cure for narcolepsy, aside from the medication that you have to take to keep the symptoms at bay. In order to provide a curative treatment, we need to know more about the cause of the disorder, especially about the brain areas that are involved in and leading to such symptoms. This is exactly what a Harvard professor from the department of neurology at Beth Israel Deaconess Medical Cente, Prof. Scammell, was doing. His work on mice has contributed immensely to the better understanding of narcolepsy and cataplexy. In one particular study using mice, he was able to show that the amygdala (an almond-shaped brain region mostly responsible for emotion) might be the primary regions in the brain that responsible for triggering the cataplexy symptom of narcolepsy. He concluded that the increased neuronal activity in this brain area (amygdala) due to an extremely emotional experience might be directly responsible for triggering cataplexy by inhibiting the brain stem (another brain area at the base of the brain), which leads to the muscle weakness or paralysis they experience.
Even though this research was performed on mice, it provided us with ample information on the brain regions and the pathways involved in such disorder. However, we shouldn’t stop here. Understanding which cells in the amygdala are directly responsible for this inhibition might provide more targeted and less symptomatic treatment options. Our team at Kyoto University was the first to report similar findings to those reported by Dr. Schemmell. The case study published by our lab supports the conclusion that the amygdala’s function is essential for cataplexy to occur and that the brain pathway that was described in previous publications could also be seen in our patient. Our report highlights the importance of continuing research, especially clinical, on the topic of narcolepsy with or without cataplexy, as we are closer than ever to uncovering the brain regions as well as pathways that are behind this disorder.
A day will come when a drug or a minimally invasive surgical procedure is able to promise a cure for those patients, and after going through the latest research on the topic, I’m sure that this day is just around the corner!
