Hemifacial spasm: a new technique of facial nerve blockade

Morphometric and Topographic Features of Stylomastoid Foramen and its Clinical Significance in Facial Nerve Block

Objective  This study aims to determine the topographic localization of the stylomastoid foramen (SF) and its morphometric relationship with the surrounding bony landmarks. Design  A descriptive anatomical study. Setting  Anatomy Laboratory of the Faculty of Medicine. Participants  Measurements were performed on 53 dry temporal bones. Main Outcome Measures  On the inferior and lateral aspects of photographic images, lines and angles were defined. The most lateral end of the SF (SF1) and the transverse medial-lateral line that passes through the upper end of the anterior border of mastoid process (line 1) were used as reference points for topographic evaluation. The upper end of the anterior border of mastoid process (A) and the tip of mastoid process (B) were considered in defining angles. The dates about SF were evaluated using the ImageJ 1.46r software and digital caliper. Results  SF1 was classified into three different types based on its topographical localization, stated as Type 1, Type 2, and Type 3. In Type 1, SF1 was located anterior to line 1 (54.7%). SF1 was located posterior to line 1 in Type 2 (34.0%). SF1 was located just over line 1 in Type 3 (11.3%). We also detected angular variations between these types in the inferior and lateral aspects. Conclusion  The recommended angles of application are 30 degrees on the horizontal plane and 55 degrees on the sagittal plane for Type 1 when point B is considered. A needle length below 10 mm is more suitable to minimize the potential complications of the nerve block.

Hemifacial spasm: a review

Hemifacial spasm can be diagnosed by observation and clinical history. It is thought to arise primarily from compression of the facial nerve at the pons, usually by an adjacent artery. Although many approaches to treatment have been tried, the most effective is microvascular decompression of the facial nerve at the pons. That operation has well-recognized risks, including ipsilateral deafness. The latter complication ordinarily can be avoided by the use of intraoperative monitoring of auditory evoked potentials.

The treatment of hemifacial spasm with percutaneous radiofrequency thermocoagulation of the facial nerve

The authors present their first results with the treatment of hemifacial spasm by controlled percutaneous thermocoagulation of the facial nerve. Seven patients have been treated to date with good immediate results on the movements, although a slight paresis of the homolateral facial musculature, aesthetically acceptable, persists after treatment. A long-term follow-up at more than 10 months was achieved in only 3 patients, who showed a complete regression of the spasm with partial disappearance of the facial hemiparesis.