Withdrawal reaction of carbamazepine after neurovascular decompression for trigeminal neuralgia: a preliminary study.

To evaluate the representations and the relevant factors of carbamazepine-associated withdrawal reaction (CAWR) after microvascular decompression (MVD) to treat trigeminal neuralgia (TN).The present series included 90 patients who were referred from September 2010 to January 2013 and diagnosed with classical TN. The carbamazepine (CBZ) serum level was tested twice at 24h pre- and 24h post-operation by using HPLC analysis. The analysis of correlating selected factors and CAWR was performed.Among 90 patients, 26 (28.9%) suffered from post-operative CAWR for 3 days after MVD. The symptoms of CAWR include overexcitement, e.g. insomnia, dysphoria, hand fremitus, hallucination and severe headache. The history of CBZ therapy before MVD, pre-operative dosage of CBZ, and the D-value of CBZ blood concentrations demonstrated statistic differences between the patients with CAWR and those without CAWR. Patient characteristics such as gender, age, and duration of neuralgia, neuralgia-related factors including neuralgia extent and neurovascular compression severity, and operation conditions including duration of MVD procedure, effect of MVD and complication of MVD had no influence on the occurrence of CAWR.It is strongly suggested that CAWR is dependent on the pre-operative dosage and the changing rate of pre- and post-operative CBZ blood concentrations.