Predictors of outcome in surgically managed patients with typical and atypical trigeminal neuralgia: comparison of results following microvascular decompression.

OBJECT Microvascular decompression (MVD) has become one of the primary treatments for typical trigeminal neuralgia (TN). Not all patients with facial pain, however, suffer from the typical form of this disease; many patients who present for surgical intervention actually have atypical TN. The authors compare the results of MVD performed for typical and atypical TN at their institution. METHODS The results of 2675 MVDs in 2264 patients were reviewed using information obtained from the department database. The authors examined immediate postoperative relief in 2003 patients with typical and 672 with atypical TN, and long-term follow-up results in patients for whom more than 5 years of follow-up data were available (969 with typical and 219 with atypical TN). Outcomes were divided into three categories: excellent, pain relief without medication; good, mild or intermittent pain controlled with low-dose medication; and poor, no or poor pain relief with large amounts of medication. The results for typical and atypical TN were compared and patient history and pain characteristics were evaluated for possible predictive factors. CONCLUSIONS In this study, MVD for typical TN resulted in complete postoperative pain relief in 80% of patients, compared with 47% with complete relief in those with atypical TN. Significant pain relief was achieved after 97% of MVDs in patients with typical TN and after 87% of these procedures for atypical TN. When patients were followed for more than 5 years, the long-term pain relief after MVD for those with typical TN was excellent in 73% and good in an additional 7%, for an overall significant pain relief in 80% of patients. In contrast, following MVD for atypical TN, the long-term results were excellent in only 35% of cases and good in an additional 16%, for overall significant pain relief in only 51%. Memorable onset and trigger points were predictive of better postoperative pain relief in both atypical and typical TN. Preoperative sensory loss was a negative predictor for good long-term results following MVD for atypical TN.