Ehlers-danlos Syndrome and Narcolepsy: An Incidental Relationship? - Ehlers-danlos Syndrome and Narcolepsy: An Incidental Relationship? - Open Access Pub

Ehlers Danlos syndrome (EDS) is a collagenic disease that has often been associated with different types of sleep disorders ranging from insomnia to obstructive sleep apnea (OSA). EDS usually has associated fatigue and excessive daytime sleepiness (ES), thus narcolepsy should be excluded as a cause. Literature review suggests a high prevalence of hypersomnia disorders in this population. We present two sporadic cases presenting with typical symptoms of narcolepsy. DOI10.14302/issn.2574-4518.jsdr-18-2511 Ehlers Danlos Syndrome (EDS) is a genetic disorder occurring in 1 in 5000 births, with predominance in females. Its multi-systematic effects are due to abnormal mutation of the connective tissue impacting skin (i.e., hyperextensibility), blood vessels, and joints (i.e., hyperflexible joints)1. Other associated abnormalities include psychiatric, cardiac, and gastrointestinal concerns. Excessive daytime sleepiness (ES), fatigue, and other sleep disturbances are frequently reported by patients with Ehlers Danlos Syndrome2,3,4. A 9-point Brighton scale has been used to aid in diagnosis of EDS. If four or more points are detected, the scale is considered positive. However, other hyperflexibility disorders such as Marfan’s and osteogenesis imperfecta should be excluded. Sleep disorders are very common in the EDS population ranging from insomnia to obstructive sleep apnea (OSA). Due to joint involvement, pain might interrupt sleep causing insomnia. Due to the associated cartilaginous defects, laryngo-tracheomalacia, chest deformities, scoliosis, dilated aorta causing tracheal compression, and vocal cord abnormalities, a higher prevalence of OSA is expected4,5,6. Other comorbid sleep disorders in this population include periodic limb movement disorder and circadian rhythm sleep disorders. Primary hypersomnia or narcolepsy was found in 21.3% of the population7. Narcolepsy is a disorder characterized by excessive daytime sleepiness (ES), involuntary sleep attacks due to rapid eye movement (REM) intrusion, sleep paralysis and hypnagogic or hypnopompic hallucinations. Cases associated with sudden loss of muscle tone in the setting of strong emotions (i.e., cataplexy) are type 1, while lack of cataplexy is termed type 2. Aside from the clinical presentation, a confirmation by the presence of two sleep onset REM (SOREMs) on multiple sleep latency test (MSLT) is required. In narcoleptic individuals, an average sleep onset in the 5 naps of less than 8 minutes is expected signifying ES. In non-conclusive MSLT cases, a low or deficient CSF hypocretin can aid in diagnosis.