Microvascular decompression for pediatric-onset hemifacial spasm: case series and literature review

Objectives Pediatric hemifacial spasm has been rarely reported in the literature, which contains only 44 cases. Although microvascular decompression (MVD) has been widely regarded as effective therapy for hemifacial spasm, the etiology and surgical treatment of pediatric patients are seldom reported. We report our experience with MVD for pediatric hemifacial spasm patients and review the literature with emphasis on the difference from adults. Methods This retrospective report included 4 pediatric HFS patients, who underwent MVD in our department between January 2014 and May 2021 and then reviewed all the pediatric hemifacial spasm literature on "pubmed" with emphasis on the clinical data. Results Our series included 1 boy and 3 girls with an average age of 15.6 +/- 3.2 years old; their onset ages were from 7 to 16 years old (11.6 +/- 4.3). Three patients achieved immediate excellent outcomes and 1 achieved poor immediately and became good 6 months later. During the operation, all the 4 patients were found compressed by anterior inferior cerebellar artery (AICA). The incidence of pediatric atypical hemifacial spasm patients is 12.5% among the 48 reported cases, which is much higher than adults. Among all the reported 48 cases including ours, the singular artery neurovascular conflictions account for 27/48(56%), the singular vein and combined artery/vein conflictions in 12/48(25%) and the cisternal conflictions in 5/48(10.4%) patients. Conclusions The etiology of pediatric hemifacial spasm is still neurovascular conflict, of which combined artery/vein and singular venous compression patterns have a higher proportion, which might explain higher incidence of pediatric atypical hemifacial spasm and less favorable postoperative outcome. Sufficient arachnoid release, full exploration and decompression along the facial nerve are necessary, which would help to increase the excellent postoperative cure rate among pediatric patients.