Comparison of Prognosis After Microvascular Decompression in Combined and Single Hyperactive Dysfunction Syndrome of the Cranial Nerves

Background: Hyperactive dysfunction syndrome (HDS) of cranial nerves is caused by vascular compression of the cranial nerves and results in manifestation of specific symptoms of the involved cranial nerves. The purpose of this study was to compare the prognosis of combined and single HDS after microvascular decompression (MVD) surgery and to identify the contributing factors. Methods: From January 2001 to December 2022, a total of 5034 patients with HDS underwent 5055 MVD surgeries, of which 45 patients with combined HDS underwent 66 surgeries. Data concerning the subjects' demographic and disease-related characteristics and postoperative prognosis were collected by reviewing electronic medical records. Results: Combined HDS had metachronous onset in 86.7% of patients and bilateral involvement in 66.7%. Hemifacial spasm (HFS) followed by trigeminal neuralgia (TN) was the most common type of combined HDS (28.9%). No significant differences were observed in postoperative prognosis between combined and single HDS for HFS, TN, and glossopharyngeal neuralgia. In combined HDS, no differences were observed in postoperative prognosis according to sex, age at surgery, symptom duration, comorbidities, and offending vessels for both HFS and TN. No significant differences in postoperative complications were identified between combined and single HDS. Conclusions: The prognosis after MVD surgery for combined HDS was similar to that for single HDS. MVD can be recommended as a safe and effective treatment option for patients with combined as well as single HDS.