Dusunen Adam : The Journal of Psychiatry and Neurological Sciences :
2013;26:402-403
Full Text:Dear Editor,
Narcolepsy is a sleep disorder that causes functional impairment and it is underdiagnosed since it is rare (1). Main symptoms of narcolepsy include daytime excessive sleepiness and sleep attacks, cataplexia due to sudden loss of muscle tone in response to planned or unexpected situations, sleep paralysis, hypnogogic and hypnopompic hallucinations (2). The term “narcolepsy” was used for the first time in 1880 by a French physician, Gélinea, to describe excessive sleepiness during daytime, sleep attacks and muscle weakness triggered by emotions in a patient (1).
While narcplepsy is a clinical diagnosis, polysomnography, MSLT (Multiple Sleep Latency Test) and measurement of hypocretin levels in cerebro spinal fluid are necessary for definite diagnosis. MSLT is a laboratory method which is used to detect REM onset sleep periods and daytime sleepiness. Mean sleep latency must be shorter than 8 minutes in polysomnography and MSLT, and must include two REM onset sleeps (3). There are three types of the disorder: with cataplexy, without cataplexy, and due to general medical condition (4).
Narcolepsy can be frequently misdiagnosed as another psychiatric condition or epilepsy variant (1). The main reason to miss narcolepsy diagnosis may the overlap of symptoms with other disorders. For example, there are some case reports on differential diagnosis with schizophrenia. Hypersomnia and impaired sleep-wakeness cycle may lead to unusual and bizzare behaviors resembling disorganised behaviors in schizophrenia (5).
Hypersomnia during the daytime leads to severe sleep deprevation and chronic fatigue. Along with these, additional depressive symptoms might lead the clinician to atypical mood disorder diagnosis. Laboratory tests are quite important in the differential diagnosis.
Narcolepsy can also be confused with epilepsy. Cataplexy and sleep attacks can be intrepreted as epileptic seizures. Conciousness, postictal confusion and auras are important in differential diagnosis. Main way to make differential diagnosis is laboratory evaluations.
When untreated, patients with narcolepsy are at great risk for various, different types of accidents. Appropriate and comprehensive treatment protocols must be used to secure these patients and those around them (6). In order to prevent daytime sleep attacks, beginning the treatment with sleep hygiene is an effective method. Suggesting the patients to have small naps decrease the frequency of sleep attacks after waking up (7). Methylphenidate and amphetamine derivates; modafinil, which is preferred because of its long acting and lack of tolerance and dependence; pemoline and mazindol have been used to treat daytime hypersomnia and sleep attacks. In order to treat cataplexy and other symptoms, tricyclic antidepressants, MAO inhibitors, selective serotonin reuptake inhibitors, noradrenaline and serotonine reuptake inhibitors have been used. Short acting hypnotics can be used to treat impaired nighttime sleep (1,8).
In conclusion, before narcolepsy diagnosis is made, usually other psychiatric and neurological disorders, particularly epilepsy, come to mind. Therefore, there is a long period between the emergence of first symptoms and diagnosis. We wanted to remind our colleagues this diagnosis to shorten the period and to make diagnostic laboratory evaluations.
REFERENCES
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