![]() ![]() Orexin, also called hypocretin, is a neurotransmitter that regulates arousal, wakefulness, and appetite. This finding suggests that narcolepsy with cataplexy only enuses when a patient loses almost all their orexin-positive cells. Importantly, a postmortem study of a patient who exhibited narcolepsy without cataplexy indicated loss of 33% of orexin-positive cells, largerly in the posterior hypothalamus. More than 90% of patients with narcolepsy and cataplexy present with low levels of orexin (<110 pg/ml) in CSF, which undoubtedly stem from the loss of approximately 90% of orexin-expressing neuron. Men often experience a higher number of cataplectic attacks than do women. Cataplexy persists throughout life, altought the frequency of attacks might decrease with age. The frequency of attacks in patients varies from fewer than one episode per year to several episodes per day. The duration of an attack varies from several seconds to several minutes (rare hours)-status cataplectitus. Most episodes are accompained by reduced heart rate and EEG desynchronization. Skeletal muscke tone is reduced or absent during a cataplectic episode. Some patients with narcolepsy report hypnagogic hallucinations during attack, and some patients enter into REM sleep, but this is rare. During a cataplectic attack, patients remain conscious and are able to remember what happened to them before, during and after the cataplectic episode. 50% of patients with cataplexy experiece both partial muscle weakness and complete paralysis, whereas 30% experience only partial paralysis. Extreme muscle weakness in the knees, arms and shoulder is also common. Typically the result is dysarthria, twitching of the facial muscles, jaw tremor. Cataplexy affects all skeletal muscles apart from the diaphragm and extraocular muscles, but its greatest effect is on facial and neck muscles. These attacks are debilitating for patients because they leave the affected individual awake but either fully or partially paralyzed. To overcome these consequences early diagnosis and treatment are essential to best improve patient quality of life.Ĭataplexy associated with narcolepsy: epidemiology, pathophysiology and management, 2006 SYMPTOMS OF CATAPLEXYĬataplexy can be difficult to diagnose, as the symptoms vary not only between patients but also within individuals.Ĭataplectic attacks range from partial muscle weakness to complete paralysis, but are always bilateral, even if one side of the body is more affected than the other. In Europe, the delay between the onset of symptoms and a correct diagnosis is about 10 years, and many patients are affected during the most important period in their education and/or career. Patients with narcolepsy have difficulty in executing daily activities, socializing and maintaining personal relationships mainly due to cataplexy and EDS, and are estimated to experience a quality of life that is comparable or inferior to that of patients with epilepsy or sleep apnoea.Ĭataplexy is still an under-recognized symptom of narcolepsy- a disease that is currently underdiagnosed. The age of oneset of narcolepsy ranges from early childhood to the fifth decade (with a peak at 15 years and 35 years of age). Cataplexy is the optimal behavioural biomarker of this disease. In addition to cataplexy, narcolepsy is characterized by sleep paralysis, sleep-onset REM periods, hypnagogic hallucinations and fragmented night-time sleep. Cataplexy is defined as a sudden involuntary muscle weakness or paralysis during wakefulness, typically triggered by strong emotions, and is the pathognomonic symptom of narcolepsy with cataplexy ( a sleep disorder that affects 0,06% of the adult population). ![]()
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