Role of neuroimaging in cases of primary and secondary hemifacial spasm

PURPOSE: The objective of this study was to analyze the role of neuroimaging and documenting various intracranial pathologies in primary and secondary hemifacial spasm. METHODS: This retrospective study included patients with HFS who had undergone neuroimaging. The demographic profile, onset, progression, neuroimaging findings, and types of HFS were documented and analyzed. RESULTS: A total of 202 patients (male = 110, female = 92) were included. The mean age of the study population was 51.81 ± 11.76 years. The right side was involved in 104 patients, the left side was involved in 97 patients and bilateral involvement was observed in one patient. Primary HFS: secondary HFS was 9.6:1. The mean age of onset of the spasms in the primary HFS group was 49.26 ± 8.35 years and in secondary HFS was 43.13 ± 12.12 years respectively. The anterior inferior cerebellar artery was the major vessel causing neurovascular conflict in primary HFS (n = 55). Facial nerve palsy was the most common cause (n = 13) of secondary HFS followed by cerebellopontine angle (CPA) tumors. CONCLUSION: The hemifacial spasm occurs mostly in the fifth decade of life. Primary HFS is more prevalent than secondary HFS. Clinical distinction between them is difficult. Neuroimaging is essential to detect the conflicting vasculature in cases of primary HFS and pathologies like CPA tumor, cyst, and aneurysms in cases of secondary HFS.