The effect of microvascular decompression in patients with multiple sclerosis and trigeminal neuralgia

Trigeminal neuralgia (TN) in patients with multiple sclerosis (MS) is thought to be caused by demyelinating plaques within the nerve root entry zone, the trigeminal nucleus, or the trigeminal tracts.

To review our experience of microvascular decompression (MVD) in patients with MS and symptomatic TN.

All first-time MVDs for symptomatic trigeminal neuralgia in patients with MS performed by the senior author during an 8-year period (1999-2007) in this department were reviewed. The preoperative pain components were differentiated as being 100% episodic pain, > 50% episodic pain, or > 50% constant pain. At follow-up, pain relief was assessed with a standard mail questionnaire; those still having residual pain were further examined in the outpatient clinic or interviewed by phone.

Of the 19 MS patients, 15 were available for follow-up. The median observation period was 55 months (range, 17-99 months). At follow-up, 7 of 15 patients (47%) were completely free of their episodic pain, and an additional 4 (27%) had significant relief of episodic pain (ie, worst pain marked as 0 to 3 cm on a 10-cm visual analog scale). Among the subgroup of 8 patients with a constant pain component, all were free of their constant pain, and 4 (50%) were free of their episodic pain.

In our 8-year experience of doing MVD in MS patients with TN, we found complete and significant relief of episodic TN in a large proportion of patients. Even those with a constant pain component before MVD were completely relieved of their constant pain. Thus, in patients with TN (with or without a constant pain component), the presence of MS should not prevent patients from being offered MVD.