Journal of Clinical Neuroscience 20 (2013) 440–445

Long-term prognostic factors for microvascular decompression
for trigeminal neuralgia

Kwang Wook Jo, Doo-Sik Kong, Ki-Sun Hong, Jeong A Lee, Kwan Park


The purpose of this retrospective study was to identify preoperative imaging characteristics and surgical
findings that predict pain relief after microvascular decompression (MVD) for trigeminal neuralgia (TN).
This study included 141 patients with follow-up ranging from 6 months to 10 years (mean followup
= 26.3 months). Preoperative images were assessed in 90 patients who were evaluated with constructive
interference in steady-state (CISS) MRI in the last 6 years. These findings were compared with the
severity of neurovascular conflict (NVC) found at operation to identify imaging findings useful for prognosis.
Using Kaplan–Meier analysis, we found that the success rate of MVD was 91.1 ± 2.5% at 1 year and
was 76.3 ± 7.5% after 5 years. A higher degree of NVC at operation (p = 0.000), no vein compression
(p = 0.049) and single vessel compression (p = 0.000) were good prognostic factors for pain relief. Two
meaningful positive MRI findings, specifically, the ‘‘cerebrospinal fluid rim sign’’ and the ‘‘deviation sign’’
were statistically significantly associated with the severity of NVC at operation and MVD success
(p = 0.000). In this study, 34 patients (24.1%) complained of facial numbness postoperatively, and the oral
herpes simplex virus was reactivated in 19 patients (13.4%). The involvement of a single arterial offender
in NVC is the most important prognostic factor for MVD in TN, and the positive MRI findings described
in this report may be helpful in selecting patients for MVD.