الفهرس 
• IntroductionOnly 14 pages are availabe for public view
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Abstract
Obstructive sleep apnea is the most common respiratory sleep
disorder and its incidence is increasing due to the obesity epidemic and
aging population. It has been estimated that symptomatic OSA affects up
to 10% of middle-aged men and 3% of middle-aged women. OSA is
caused by recurrent incidents of upper airway obstruction while sleep that
lead to periodic oxyhemoglobin desaturations and arousals from sleep.
Disturbances in sleep and oxygenation are believed to be responsible for
the major clinical manifestations of this disorder, which include excessive
daytime sleepiness, arterial and pulmonary hypertension, and
cardiopulmonary failure. Untreated OSA has been linked to
neurocognitive impairment and motor vehicle accidents.
The aim of therapy is to avert or alleviate the clinical squeals of this
disorder by relieving upper airway obstruction during sleep. One of the
most effective options of treatment is the Continuous Positive Airway
Pressure (CPAP), but adherence to the therapy is often poor despite
efforts to improve it. Low adherence rates of 39% to 50% over time limit
its effectiveness and result in a significant number of untreated patients
with symptomatic OSA.
Electrical stimulation of the hypoglossal nerve, has been explored
as an option of treatment because one of the factors contribute to OSA
pathogenesis is decreased tone during sleep in the upper airway dilator
muscles especially the genioglossus. At first electrical stimulation of
genioglossus using intramuscular or transcutaneous electrodes has been
tried. The studies demonstrated improvements in airway patency and OSA
severity, but muscle stimulation disrupted sleep and increasing arousals
because of sensory effect. As a result, direct electrical stimulation of the
motor nerve innervating the genioglossus muscle which is the hypoglossal
nerve (HGN) has been explored as an alternative choice.
Summary
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Hypoglossal nerve stimulation results in significant improvement of
primary outcome measures of OSA with significant reduction of apnea
episodes. It could be considered as an effective -but still of high costalternative
for OSA patients. Further studies comparing HNS to other
therapies are needed