Effect of microvascular decompression in trigeminal neuralgia patients with or without constant pain

OBJECTIVE: To study the effect of microvascular decompression (MVD) in trigeminal neuralgia (TN) patients with or without constant pain. METHODS: The study includes all first-time MVDs for facial pain performed by the senior author (PIKE) during the 6-year period from 1999 to 2005 in the Department of Neurosurgery at the National Hospital. At the time of follow-up, pain relief was assessed using a standard mail questionnaire; those patients still having residual pain were further examined in the outpatient clinic or interviewed by phone. RESULTS: The total study population includes 135 patients who underwent initial MVDs (67% of MVDs for TN without constant pain and 33% of MVDs for TN with constant pain). At the time of follow-up, the response rate was 95%, which provided us with 128 patients. The median observation period was 38 months (range, 12-87 mo). For episodic pain, MVD caused complete (i.e., 100%) pain relief in 78% of TN patients without constant pain and in 77% of TN patients with constant pain before MVD, and a significant pain relief (i.e., worst pain marked as 0-3 cm on a 10-cm visual analog scale) in 85 and 81%, respectively. For constant pain, MVD caused complete pain relief in 70% of the TN patients with constant pain before MVD, and significant pain relief in 77%. CONCLUSION: In TN patients with constant pain before MVD, significant relief of episodic and constant pain was observed in 81 and 77%, respectively. Hence, the presence of constant pain should not prevent TN patients from being offered MVD.