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Narcolepsy and Other Hypersomnias Marietta B. Bibbs, RPSGT Morton Plant Mease Healthcare Clearwater, FL Slide 2 Objectives Discuss etiology and symptoms of narcolepsy Discuss causes of excessive sleepiness Define idiopathic hypersomnia Describe other causes of hypersomnia Define the three factors that characterize sleepiness Demonstrate the dangers of drowsy driving Slide 3 What is Narcolepsy? A neurological disorder caused by deficiency of an excitatory neuro- transmitter leading to excessive sleepiness and other atypical REM-related activity. It is a chronic disorder characterized by excessive daytime sleepiness despite a restful night of sleep, and sudden and uncontrollable attacks of sleep that are sometimes accompanied by hallucinations and sleep paralysis. Slide 4 Characteristics of Narcolepsy Excessive sleepiness with cataplexy Rapid transition from wakefulness to sleep Early onset REM epochs Automatic behavior Slide 5 Narcolepsy Other Symptoms: Sleep Paralysis (waking with inability to movea frightening condition). Hypnagogic hallucinations (perceptual distortions that seem real) Characterizations: Repeated naps, lasting 10-20 minutes with sleepiness reappearing in 2-3 hour repetitious patterns. Waking up refreshed from naps Slide 6 Unique Distinctions of Narcolepsy Inability to consolidate wakefulness in the day (and sleep at night) Cataplexy (loss of muscle tone in response to strong, usually positive, emotions) Short naps are very refreshing Sleepiness returns within hours after napping Cataplexy may be localized or general, and vary from mild to very disabling. Clustered cataplexy episodes may result in status cataplecticus, lasting minutes up to an hour Slide 7 Four Primary Symptoms 1. Excessive Daytime Sleepiness (with uncontrollable sleep attacks and automatic behavior, and the most prominent symptom of narcolepsy). 2. Cataplexy (loss of bilateral peripheral muscle tone). 3. Hypnagogic Hallucinations (usually occur as vivid dreams at sleep onset). 4. Sleep Paralysis (usually occurs at sleep onset). It is rare for a person to have all four symptoms. Slide 8 Sleep Attacks of Narcolepsy Uncontrollable sleep attacks occur most often in sedentary situations, but can also occur in situations where sleep would normally not occur such as in the middle of conversation, while driving, eating, walking, etc. Narcoleptics can fight sleep attacks for a while, but eventually lose the fight and give in to the urge to sleep. Slide 9 Cataplexy The most exclusive feature of narcolepsy. Cataplexy is always precipitated by powerful emotion, such as laughter, crying, anger, etc. It is characterized by a sudden, bilateral loss of muscle tone in which consciousness and memory are intact Respiratory and ocular muscles are not affected. Slide 10 Cataplexy A catapletic attack can last from a few seconds to several minutes. The loss of muscle tone in cataplexy can be very mild (jaw dropping, slurred speech) to a complete collapse in which the person can fall to the ground. Strong emotion can sometimes precipitate episodes of cataplexy that occur in succession, called status cataplecticus). Slide 11 Onset and Diagnosis Early adolescence is the peak age of onset for narcolepsy, but it can have onset in early childhood and adulthood. Can be diagnosed with a good sleep and family history of narcolepsy. Diagnosis confirmed by polysomnography and MSLT. Slide 12 Diagnosis Clinical findings and characteristic features of polysomnography are key in the diagnosis of narcolepsy The Multiple Sleep Latency Test (MSLT) confirms the diagnosis and the severity of excessive sleepiness. Slide 13 Automatic Behavior in Narcolepsy Performing a routine task automatically without conscious awareness. The narcoleptic patient continues to perform the task while falling asleep (microsleep) and without memory of performing the action. Slide 14 Nocturnal Sleep Disturbance Narcoleptic patients fall asleep easily, but often complain of trouble staying asleep during the night, despite the fact that they may experience sleepiness and fall asleep repeatedly during the day. Narcoleptics dont sleep more than normal people over the 24-hour cycle, but they do have frequent awakenings or excessive shifts to stage N1. Slide 15 Diagnostic Criteria.. Narcolepsy with Cataplexy Narcolepsy without Cataplexy Narcolepsy Due to Medical Conditions Slide 16 Diagnostic Criteria. A complaints of excessive daytime sleepiness occurring daily for at least 3 months. EDS cannot be explained by another sleep disorder, medical or neurological disorder, medication use or substance use. A definite history of cataplexy (sudden and transient episodes of loss of muscle tone triggered by emotions). Slide 17 Diagnostic Criteria.. C onfirmation of the disorder through multiple sleep latency testing (MSLT). The MSLT results in a mean sleep latency less than or equal to 8 minutes with two or more sleep onset REM periods (SOREMPS) observed following sufficient nocturnal sleep of a minimum of 6 hours. The Stanford Sleepiness Scale and Epworth Sleepiness Scale can be used to aide in the clinical diagnosis of Narcolepsy. Slide 18 Other Diagnostic Tools HLA typing can be used since there is a strong correlation of narcolepsy in individuals with cataplexy when human leukocyte antigen typing is positive for DQB*0602 or DR2. Slide 19 HLA Typing Although the test can be used to confirm narcolepsy diagnosis, it is not very useful in ruling out narcolepsy. If presence of DR2 or DQB1*602 are positive, this does not directly indicate narcolepsy, but indicates that the person has a genetic predisposition to develop the disease. HLA typing assists in determining the risk level in families of narcoleptic patients. Almost all narcoleptic patients will have presence of HLA-DR2 and DQ1. In narcoleptics with cataplexy, 90-100% of them will have the DQB1*602 allele regardless of their race. Slide 20 Developments on Narcolepsy The etiology of narcolepsy is now better understood, and the pathophysiology of narcolepsy is recognized and linked to defects in the orexin (hypocretin) neuropeptide system resulting in impaired control of sleep and wakefulness. Most cases of narcolepsy in humans have been associated with low or absent cerebrospinal fluid levels of hypocretin. Slide 21 The Orexin Connection Patients who have Narcolepsy with cataplexy are associated with loss of approximately 50,000- 100,000 hypothalamic neurons containing Orexin. Hypocretin (Orexin) levels in CSF