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Facial nerve decompression is a type of nerve decompression surgery where abnormal compression on the facial nerve is relieved. == Causes of facial nerve compression == Pressure and compression of any cause on a peripheral nerve can cause nerve impulse block. That is, the nerve is no longer able to send electrochemical impulses, and hence does not send signals to the brain or from the brain to muscles. There may also be demyelination (loss of the nerve's myelin sheath) and degeneration of the nerve in the affected area but it does not effect axons beyond this site. The facial nerve is a mixed nerve (i.e. containing both sensory and motor nerve fibres) and therefore compression can create sensory (e.g. anesthesia - numbness, or paresthesia - tingling) and motor deficits. Early surgical intervention tends to be carried out because after three to four months, fibrosis (replacement with fibrous tissue) occurs in a significant portion of nerve fibers, and after that decompression is not of much value. There are three main patterns of facial nerve compression. The type of injury also gives an idea about the prognosis. * Neuropraxia: no wallerian degeneration and complete and rapid recovery of function. * Axonotmesis: wallerian degeneration and necrosis of the distal segment (death of the part of the nerve after the compression). Recovery is not complete. * Neurotmesis: this type of injury involves the endoneurium with wallerian degeneration. Recovery is difficult. There are several specific causes of facial nerve compression, discussed below. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Facial nerve decompression」の詳細全文を読む スポンサード リンク
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