Bell’s Palsy-Tertiary Ischemia: An Etiological Factor in Residual Facial Palsy

摘要

The facial nerve is unique among the motor nerves. It has long and tortuous course through the temporal bone and within the Fallopian canal. Because of this it is more prone to paralysis than any other nerve in the body. The most frequent type of facial palsy is Bell’s palsy. This is an acute idiopathic lower motor neuron palsy of the facial nerve which does not normally progress and which is most usually unilateral and self limiting,: the majority of cases remit within 4–6 months and nearly always remission is complete by 1 year. In those cases that do not recover it is my contention that this is caused by Either the progression, or after effects, of secondary ischemia: tertiary ischemia. In turn this causes thickening of the facial nerve sheath with a fibrous band or bands forming with resultant strangulation and compression of the nerve, which hampers its recovery. In such cases facial nerve decompression with slitting of the sheath and cutting of any fibrous bands would be the preferred management when allied with aggressive medical therapy.