Microvascular decompression for trigeminal neuralgia: comments on a seriesof 250 cases, including 10 patients with multiple sclerosis

Objective-To examine surgical findings and results of microvascular decompr ession (MVD) for trigeminal neuralgia (TN), including patients with multipl e sclerosis, to bring new insight about the role of microvascular compressi on in the pathogenesis of the disorder and the role of MVD in its treatment . Methods-Between 1990 and 1998, 250 patients affected by trigeminal neuralgi a underwent MVD in the Department of Neurosurgery of the "Istituto Nazional e Neurologico C Besta" in Milan. Limiting the review to the period 1991-6, to exclude the "learning period" (the first 50 cases) and patients with les s than 1 year follow up, surgical findings and results were critically anal ysed in 148 consecutive cases, including 10 patients with multiple sclerosi s. Results-Vascular compression of the trigeminal nerve was found in all cases . The recurrence rate was 15.3% (follow up 1-7 years, mean 38 months). In f ive of 10 patients with multiple sclerosis an excellent result was achieved (follow up 12-39 months, mean 24 months). Patients with TN for more than 8 4 months did significantly worse than those with a shorter history (p<0.05) . There was no mortality and most complications occurred in the learning pe riod. Surgical complications were not related to age of the patients. Conclusions-Aetiopathogenesis of trigeminal neuralgia remains a mystery. Th ese findings suggest a common neuromodulatory role of microvascular compres sion in both patients with or without multiple sclerosis rather than a dire ct causal role. MVD was found to be a safe and effective procedure to relie ve typical TN in patients of all ages. It should be proposed as first choic e surgery to all patients affected by TN, even in selected cases with multi ple sclerosis, to give them the opportunity of pain relief without sensory deficits.