Narcolepsy

Extract

[...] hallucinations. Commonly misconceived as representing low intelligence and/or poor motivation. Syndrome frequently overlooked, with an average of 15 years of symptoms prior to diagnosis. Onset usually in teenage years. EPIDEMIOLOGY Predominant age: Mean age at onset 18 years Predominant sex: Male = Female ALERT Pediatric Considerations Uncommon in childhood Prevalence One in 3,000 diagnosed RISK FACTORS Head trauma CNS infectious disease Anesthesia Family history Genetics Autosomal recessive Increased incidence in families with positive history Incidence in 1st-degree relative of index case is (vs general population) Biologic marker HLA-DR2 allele on short arm of chromosome 6 in 100% of white patients; 1/3 normal subjects are also positive. [...]

[...] Glass Layers NARCOLEPSY DESCRIPTION Disorder of unknown etiology characterized by excessive sleepiness typically associated with cataplexy and other REM sleep phenomena, such as sleep paralysis and hypnagogic hallucinations. Commonly misconceived as representing low intelligence and/or poor motivation. Syndrome frequently overlooked, with an average of 15 years of symptoms prior to diagnosis. Onset usually in teenage years. EPIDEMIOLOGY Predominant age: Mean age at onset 18 years Predominant sex: Male = Female ALERT Pediatric Considerations Uncommon in childhood Prevalence One in 3,000 diagnosed RISK FACTORS Head trauma CNS infectious disease Anesthesia Family history Genetics Autosomal recessive Increased incidence in families with positive history Incidence in 1st-degree relative of index case is (vs general population) Biologic marker HLA-DR2 allele on short arm of chromosome 6 in 100% of white patients; 1/3 normal subjects are also positive. [...]

[...] or t.i.d.; maximum dose 100 mg/d Dextroamphetamine: 5-30 mg b.i.d. Pemoline (Cylert): Longer half-life (than methylphenidate), 8-10 hours. Initial dose 37.5 mg/d divided a.m. and noon; maximum dose 150 mg/d. Monitor liver function studies 4 weeks after start and then once a year. No longer routinely used due to hepatotoxicity. Dextroamphetamine: Initial dose 15 mg/d divided b.i.d. or t.i.d.; maximum dose 100 mg/d Combination of long and short acting: Pemoline plus single or multiple doses of methylphenidate Auxiliary symptoms (cataplexy, hypnagogic hallucination, sleep paralysis): Antidepressants suppress REM sleep - Imipramine 75-150 mg/d - Protriptyline 10-40 mg/d - Clomipramine 150-250 mg/d - Fluoxetine 20-60 mg/d - Venlafaxine: 75-150 mg b.i.d. [...]

[...] CSF hypocretin-1 level low: 99% specificity sensitivity; useful in children unable to do MSLT SIGNS AND SYMPTOMS Tetrad: 10-20% with all symptoms - Excessive daytime sleepiness, cataplexy, sleep paralysis, hypnagogic hallucinations most common symptoms) Excessive daytime sleepiness and sleep attacks: Primary symptom, most severe form of narcolepsy - Instantaneous, irresistible REM sleep - 1st and most disabling symptom - Tendency to take naps lasting 5-10 minutes - Episodes last minutes to hours - 1-8 naps per day, 24-hour duration of sleep normal - Increased in monotonous environment, warm environment, after a large meal, or with strong emotions - 20-25% of all patients with excessive somnolence Cataplexy: Auxiliary symptom - Sudden bilateral weakness of skeletal muscles - Provocation by sudden strong wave of emotion - Lack of impairment of consciousness and memory - Short duration (less than a few minutes) - Responsiveness to treatment with clomipramine and imipramine) - Can be limited to a particular muscle group (e.g., jaw droop with inability to speak; arm, neck, or leg weakness Sleep paralysis: Auxiliary symptom - When falling asleep or on awakening, patient wants to move but cannot - Brain wakes from sleep while body remains in REM sleep - Lasts seconds to minutes - Patients are aware of events around them, but cannot open eyes or move - Can be preceded by hallucinatory phenomena - 50% of normal population have 1 or more episodes (nonspecific) Hypnagogic hallucinations: Auxiliary symptom - Vivid, frightening auditory or visual illusions or hallucinations at onset of sleep - Dreamlike experiences that occur during wakefulness or suddenly at sleep onset - Characteristic hallucinations include seeing human or animal faces or feeling that someone else is in the room. [...]

[...] Pemoline (Cylert): Longer half-life (than methylphenidate), 8-10 hours. Initial dose 37.5 mg/d divided a.m. and noon; maximum dose 150 mg/d. Monitor liver function studies 4 weeks after start and then once a year. No longer routinely used due to hepatotoxicity. Dextroamphetamine: Initial dose 15 mg/d divided b.i.d. or t.i.d.; maximum dose 100 mg/d Combination of long and short acting: Pemoline plus single or multiple doses of methylphenidate Auxiliary symptoms (cataplexy, hypnagogic hallucination, sleep paralysis): Antidepressants suppress REM sleep - Imipramine 75-150 mg/d - Protriptyline 10-40 mg/d - Clomipramine 150-250 mg/d - Fluoxetine 20-60 mg/d - Venlafaxine: 75-150 mg b.i.d. [...]