10 , 13
is delayed diagnosis of up to 10-15 years . Narcolepsy is divided into two categories , type 1 and type 2 . A diagnosis of type 1 occurs with the presence of one or both of the following : a hypocretin-1 deficiency (< 110 pg / mL or less than one-third of the normative values with the same standardized assay ) or mean sleep latency of less than eight minutes on the multiple sleep latency test ( MSLT ) with sleep-onset REM movements periods ( SOREMP ) and cataplexy . 14 A MSLT does not have to be performed for the diagnosis of narcolepsy type 1 . A few challenges arise when it comes to diagnosing children based on MSLT . The diagnostic yield of MSLT in children less than 5 years of age and normative data in this age are scant . 15 Young children have difficulty in understanding and complying with the testing instructions . Normal sleep physiology in children may vary with Tanner staging . 15 The above factors contribute to the difficulty in interpreting the MSLT . Recent reports suggest that false negatives results exist in the MSLT for pediatric narcolepsy . 15 One study that included children aged 6 to 18 years found that nocturnal SOREMP had a 97.3 % specificity but poor sensitivity of 54.8 %. 16 MSLT is also an expensive test which requires prior authorization .
CSF hypocretin level testing is more cost
15 17 , 18
effective and less time consuming . This substance is a neuropeptide that helps regulate sleep and arousal in the human body . 19 Analysis of CSF samples should only be performed by laboratories equipped to do so . Results may take up to three weeks . Determining CSF hypocretin levels early in the evaluation , when narcolepsy is suspected , can lead to a prompter diagnosis . Recognizing the symptoms and signs stated above with appropriate referral to a sleep medicine specialist can also decrease parental anxiety and frustration and promote decreased healthcare costs .
CONCLUSION
Our case highlights the importance of recognizing the unusual presentations of pediatric narcolepsy , which can be confused with neurologic and psychiatric disorders . Although hypersomnolence is the classic symptom that physicians and the lay population associate with narcolepsy , clinicians are reminded that children can present with slurred speech , motor weakness , and other motor phenomenon . A thorough evaluation is necessary for a timely diagnosis , and we emphasize that CSF hypocretin levels should be obtained in pediatric patients suspected of having narcolepsy type 1 .
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