Clinicopathological review of patients with and without multiple sclerosis treated by partial sensory rhizotomy for medically refractory trigeminal neuralgia: a 12-year retrospective study.

BACKGROUND: Trigeminal nerve root entry zone demyelination has been implicated as a cause of trigeminal neuralgia (TN) in multiple sclerosis (MS) and patients with nerve root vascular compression. We have examined the relationship between pathology and treatment outcome in patients with and without MS, treated for intractable TN by partial sensory rhizotomy (PSR).

METHODS: We reviewed the operative records, electron microscopic biopsy findings and post-operative satisfaction and pain scores of 23 MS and 47 non-MS patients who underwent PSR between 1992 and 2004.

RESULTS: The MS and non-MS patients had similar ages of onset of TN, duration of symptoms, age at surgery and proportions with typical and atypical symptoms. Demyelination was present in 16 MS and 23 non-MS patients (p=0.129), and a compressing vessel in 5 MS and 23 non-MS patients (p=0.039). Of those with demyelination, vascular compression was documented in 3 MS and 15 non-MS patients (p=0.008). Pain and satisfaction scores were similar in both groups. Recurrent TN was more commonly associated with a compressing vessel (p=0.019).

CONCLUSIONS: TN is frequently associated with nerve root entry zone demyelination in MS and patients with nerve root vascular compression. The characteristics of the TN and response to PSR are similar in both groups. Persistent vascular compression increases the risk of recurrent TN after PSR.