[Role of endoscopy and vascular decompression in the treatment of hemifacial spasm].

Although it has long been hypothesized that hemifacial spasm could arise from a conflict between the nerve and the artery, it is very difficult to distinguish between a normal arterial loop and a pathological conflict leading to facial symptoms. Several new elements would help in the definition of the cause and allow less traumatic treatment of idiopathic hemifacial spasm. They include magnetic resonance imagery with CISS sequences, limited retrosigmoid approach, endoscopy of the cerebellopontine angle and monitoring the facial nerve. In our experience with 20 cases, retrosigmoid approach with a combined surgical and endoscopic procedure has led to total involution of the spasms in 80% of the cases.