Simply put, the brain does not pass through the normal stages of dozing and deep sleep but goes directly into (and out of) rapid eye movement (REM) sleep.As a consequence night time sleep does not include as much deep sleep, so the brain tries to "catch up" during the day, hence excessive daytime sleepiness. People with narcolepsy may visibly fall asleep at unpredicted moments (such motions as head bobbing are common). People with narcolepsy fall quickly into what appears to be very deep sleep, and they wake up suddenly and can be disoriented when they do (dizziness is a common occurrence). They have very vivid dreams, which they often remember in great detail. People with narcolepsy may dream even when they only fall asleep for a few seconds. Along with vivid dreaming, people with narcolepsy are known to have audio or visual hallucinations prior to falling asleep.Narcoleptics can gain excess weight; children can gain 20 to 40 lb (9 to 18 kg) when they first develop narcolepsy; in adults the body-mass index is about 15% above average. Causes
The exact cause of narcolepsy is unknown, and it may be caused by several distinct factors. The mechanism involves the loss of orexin-releasing neurons within the lateral hypothalamus (about 70,000 neurons).Some researches indicated that people with type 1 narcolepsy (narcolepsy with cataplexy) have a lower level of orexin (hypocretin), which is a chemical contributing to the regulation of wakefulness and REM Sleep.
Gastric atresia is a congenital defect with complete occlusion of the pyloric outlet of the stomach. Cause
Gastric atresia is a birth defect. It can be genetic, inherited in an autosomal recessive manner, and associated with conditions like Down syndrome and junctional epidermolysis bullosa (medicine). In about 60% of cases, the outlet of the stomach is covered by a membrane. In around 35% of cases, solid tissue blocks the outlet. In the remaining cases (less than 10%), there is a complete separation of the stomach and the small intestine. Diagnosis
Polyhydramnios is often seen during pregnancy, and prenatal diagnosis is common. Infants with gastric atresia will exhibit forceful vomiting upon the first feeding. Imaging is required for diagnosis. Treatment
Treatment is surgical and involves removing or bypassing the obstruction. Epidemiology
It is seen in approximately 1 in 100,000 live births. == References ==