A Severance Hospital team led by Professor Chang Jin-woo장진우 has sharply reduced hearing loss, a significant side effect occurring in patients who undergo facial seizure surgery, the hospital said Monday.
The team released the results of its study where 1,434 patients -- 1,033 females and 401 males with mean age of 51.4 years -- underwent microvascular decompression for hemifacial spasms (HFS) from March 2003 to October 2016.
HFS is a rare neuromuscular disease characterized by irregular, involuntary muscle contractions on one side of the face. Most are not related to disorders such as brain tumors or cerebrovascular malformations. However, patients feel fear in the interpersonal relationship because of uncontrollable facial convulsion.
Although the most frequent cause is a blood vessel pressing on the facial nerve at the spot where it leaves the patient's brain stem, sometimes there is no known cause. The use of anticonvulsant drugs and Botox injections have been used, but remission is frequent due to the relief of symptoms.
The facial nerve microvascular decompression is the most successful treatment to relieve pressure applied to facial muscles. However, secondary complications associated with surgery such as facial paralysis or hearing loss, which are inevitable for some patients after surgery, remain a challenge. In particular, hearing loss has a profound effect on the patient's social life and quality of life.
|Professor Chang Jin-woo|
The researchers have shown that neural surveillance is performed thoroughly in the procedure of microvascular decompression, and more detailed surgical techniques show a lower rate (1.1 percent) than the reported hearing loss rate (2.3-21.2 percent).
The average follow-up of 31.7 months showed that 93 percent of 1,333 patients in the study group had a 90 percent reduction in the degree of facial seizures.
Facial paralysis was mostly temporary, with permanent facial paralysis occurring at a rate of only 0.3 percent, far less than the 22.7 percent reported.
Most of the cases (0.7 percent) showed temporary hearing impairment. Permanent hearing impairment was significantly lower than the 2.3-21.2 percent reported in the previous report.
"When performing microvascular decompression, use a fine surgical technique such as minimizing traction of the cerebral cortex and minimizing nerve damage by using microscissors to sharpen the incision of the brain spider membrane,” Professor Chang said. “Improvement of the surgical method and thorough nerve monitoring could reduce hearing loss and lead to effective treatment results.”
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