Immediate and Long-Term Outcomes of Microvascular Decompression for Mixed Trigeminal Neuralgia

BACKGROUND: Classic trigeminal neuralgia (TN) involves sharp, shooting pain in any trigeminal nerve distribution, whereas atypical TN presents with constant aching, numbness, or burning that can appear with classic features, leading to a mixed presentation. Microvascular decompression (MVD) is an effective treatment for classic TN, but its utility in treating mixed TN has been less well studied. METHODS: We retrospectively studied 73 adult patients with mixed TN and 386 patients with classic TN who underwent MVD between December 2007 and October 2016. Recorded variables included demographic data, graded radiologic and intraoperative findings, and graded pain outcomes in the immediate postoperative period (up to 3 months after MVD) and during long-term follow-up. RESULTS: The mean age of the 73 patients with mixed TN was 53.2 years. In terms of immediate postoperative outcomes, 67 patients (91.8%) experienced pain relief including improvement of atypical pain, whereas 6 patients (8.2%) had no pain relief. Having a preexisting pain syndrome (P [0.001) or distortion of the trigeminal nerve intraoperatively (P [0.001) was associated with poor surgical outcome in the patients with mixed TN. The mean duration of follow-up was 20.6 months. Forty-four patients (60.3%) developed recurrence of any TN pain. In comparison, 93% of the patients with classic TN experienced pain relief in the immediate postoperative period, and the recurrence rate was 19.9% in these patients. CONCLUSIONS: Patients with mixed TN suffer from both classic and atypical TN symptoms. Following MVD, 91.8% of our patients with mixed TN reported partial or complete pain relief, including improvement of atypical pain, in the immediate postoperative stage, compared with 93% of those with classic TN. Recurrence eventually developed in 60.3% of the patients with mixed TN.