Long-term results of microvascular decompression for trigeminal neuralgia with reference to probability of recurrence.

Sixty-one patients with trigeminal neuralgia who underwent microvascular decompression were analysed. Vascular compression of the trigeminal nerve root was found in all cases. The recurrence rate of pain in this series was 18% with an average follow-up of 80 months (range: 13 to 126 months). Ten patients developed recurrence of their trigeminal neuralgia during follow-up. Fifteen factors, including the clinical and operative findings in the pain-free patients versus the 10 patients with recurrence were analysed. Only the patients with venous compression singly or in combination with arteries were significantly related to recurrence. There was no relationship between recurrence and the duration of symptoms or the degree of compression. Based on vascular compression as the sole cause of TN, the results and interesting findings can not be explained. With reference to the hypothesis that vascular compression is only one of at least two causative factors for the development of trigeminal neuralgia, it is suggested that the intrinsic lesion in trigeminal neuralgia may be responsible for late recurrence.