Complex Neurovascular Syndromes: Is the Compressing Vessel Alone the Culprit?

To describe and correlate the clinical, radiological, and intraoperative findings in patients with refractory neurovascular syndromes (NVS) not responding to conventional medical management and to determine the surgical outcome of the microvascular decompression (MVD) procedure. Medical records of 17 patients with NVS (trigeminal neuralgia [TN] = 14 and hemifacial spasm = 3) who underwent surgery for symptom relief from January 2018 to July 2021 with follow-up data (1-36 months) were retrospectively analyzed. Patient demographics (age, sex), clinical features (site, duration of symptoms, distribution), magnetic resonance imaging (MRI) findings, micro-neurosurgical details (type of surgery, obstructive vessel), and postoperative outcome and complications were recorded.  Descriptive analysis was performed. Variables were presented as either mean and standard deviation or frequency and percentages.  The mean (standard deviation) age of patients in our study cohort was 52.6 (12.2) years. TN was common in females (64.3%). The mean duration of symptoms was longer in patients with hemifacial spasms than in patients with TN (3.3 vs. 2.7 years). While the right side was commonly affected in TN (64.3%), the left side was common in hemifacial spasm (66.7%). Most common neuralgia symptoms were distributed along the V2V3 (maxillary and mandibular division) branches (42.9%). MRI revealed neurovascular conflict in nine patients, epidermoid tumor in three patients, classical vestibular schwannoma in two patients, and short cisternal segments in three patients. Intraoperatively, superior cerebellar artery was the main offending vessel in TN followed by anterior inferior cerebellar artery (AICA) and venous compression, while tortuous vertebral artery and AICA along with thickened entangled arachnoid were seen in hemifacial spasms. Almost all patients (88.2%) reported immediate postoperative complete pain relief. One patient died secondary to chest infection after a month.  Arachnoid entanglement around the neurovascular bundle along with vascular compression over the cranial nerves is the main cause of NVS. Advanced micro-neurosurgical techniques used in MVD achieve excellent outcomes with improved quality of life. However, identifying the refractory NVS not responding to conventional medical management and early surgical management are paramount.