Microvascular decompression in patients with trigeminal neuralgia and multiple sclerosis: results and analysis of possible prognostic factors.

We evaluated the results of microvascular decompression (MVD) in patients with trigeminal neuralgia (TN) and multiple sclerosis (MS) and we studied the role of several clinical and surgical factors as possible prognosticators of good outcome. To do this we performed, to our knowledge, the first literature review with a pooled analysis of data. A PubMed search of literature was conducted using the following terms: "microvascular decompression", "trigeminal neuralgia" and "multiple sclerosis". We screened 64 articles. Of them, 7 studies were eligible for this review. As outcome indicators we used the acute pain relief (APR) and the recurrence of pain. An APR was obtained in 71.42% and a recurrence of pain was reported in 26.00% of cases, respectively. At univariate analysis, younger age at surgery (p = 0.0419) and performing MVD as the first treatment (p = 0.0384) were associated to a higher probability of APR. The evidence of an MRI brainstem lesion related to the TN (p = 0.0482) was associated to a lower probability to obtain an APR after MVD. None of the evaluated factors affect the probability of recurrence of pain. At multivariate analysis the evidence of a brainstem MRI lesion related to the TN emerged as a negative prognosticator of APR (p = 0.0169). Our literature pooled analysis showed that MVD is effective in treating patients with MS-related TN. The evidence on MRI of a demyelinating plaque related to the TN is associated with a worse response to MVD. These data could suggest that MVD would be indicated mainly in patients without brainstem MRI lesions.