Surgery is more frequent in patients with multiple sclerosis (MS) who have higher disability at the onset of trigeminal neuralgia (TN) and a longer interval between MS and TN onset compared with patients with MS and lower levels of disability at TN onset, according to a study in Multiple Sclerosis and Related Disorders. The study also found that patients with MS and high disability at TN onset have pain that is more frequently bilateral, experience lower frequency of pain remission, and have lower discontinuation rates for preventative medicines.
The RIREMS group (Rising Researchers in MS), which consisted of Italian neurologists with expertise in MS, included in this retrospective study saw a total of 298 patients with MS and a TN diagnosis over the course of a 2-year period. In this patient population, approximately 10% of cases had TN onset 5±3 years (range, 1-15 years) prior to the MS diagnosis. In the remaining patients, TN occurred after a median of 8 years from the onset of MS. The RIREMS group of neurologists created a spreadsheet that included each patient’s clinical data from clinical records. Data included information about prior and current treatments as well as type and timing of surgical procedures.
Overall, the first-choice preventative therapies for patients with MS and TN were carbamazepine and oxcarbazepine. In 30% of patients who underwent a surgical procedure, the most common procedures were gamma knife stereotactic radiosurgery (37%), microvascular decompression (22%), and radiofrequency thermocoagulation (21%). Approximately one-third of the patients with MS and TN received ≥2 surgical procedures. The use of surgery was associated with higher disability, male sex, and longer interval between MS and TN onset.
Compared with an untreated group of patients, the 77% of patients who stayed on ≥1 preventive medication had a higher disability after a mean period of 8 years. Patients with a higher disability at the onset of TN were less likely to experience pain remission, more frequently had TN that was bilateral (P =.001), and underwent surgical interventions significantly earlier (3.07±4.1 years vs 5.6±5.6 years; P =.04).
Limitations of this study included its retrospective nature as well as the lack of some clinical characteristics and aspects of treatment for some patients.
According to the researchers, the finding that TN was more frequently bilateral and surgical intervention was anticipated possibly suggests “that in patients with a longer disease history and greater demyelinating damage, pathological processes leading to TN might be more profound and less reversible.”
Ferraro, Annovazzi P, Moccia M, et al. Characteristics and treatment of multiple sclerosis-related trigeminal neuralgia: An Italian multi-centre study. Mult Scler Relat Disord. 2020;37:101461.