Trigeminal Neuralgia by Multiple Sclerosis Subtype

Trigeminal neuralgia among adults with multiple sclerosis was significantly more refractory in those with secondary progressive disease compared to other phenotypes, based on data from 58 individuals.¹

Trigeminal neuralgia (TN) is a common pain symptom of multiple sclerosis (MS), but characteristics by MS subtype are not well understood, wrote Seyed H. Mousavi, PhD, of the University of Texas Health Sciences Center at Houston, and colleagues in a recently published study.¹

Study Overview

Methods

In a retrospective review published in Multiple Sclerosis and Related Disorders, researchers identified 58 individuals from a patient database who had diagnoses of both TN and MS between 2007 and 2022.¹ The team used the Barrow Neurological Institute Pain Scale (BNI-PS) to retrospectively assess pain. A rating of BNI-PS I-III was defined as good pain control and a rating of BNI-PS IV-V was defined as poor pain control.

Findings

At the time of their TN diagnosis, a total of 44 individuals had relapsing remitting multiple sclerosis (RRMS), 11 had secondary progressive multiple sclerosis (SPMS), and the MS type was unclear for 3 patients (either RRMS or SPMS). (More on MS disease progression stages.)

Of these, 30 patients, transitioned to SPMS over a mean follow-up period of 18.8 years. Significantly more TN cases were resistant to medical management in SPMS patients compared to RRMS patients (22 vs. 9 patients, P=0.001).

In addition, TN in RRMS required significantly less pain medication compared to SPMS patients (P=0.014).

No evidence of TN was noted in patients with primary progressive MS.

Brain MRI was available for 41 patients, 27 of whom had demyelinating lesions in the trigeminal sensory pathway. Patients with lesions were significantly more likely to fail medical management than those without lesions (74% vs. 36%, P=0.017). Patients with existing lesions also were significantly more likely to need surgical intervention than those without lesions (55% versus 7%, P=0.003).

Discussion

The findings were limited by several factors including the retrospective design and relatively small study population, the researchers noted. However, the results suggest that TN is more likely to be influenced by demyelinating plaque in the trigeminal sensory pathway, and may be linked to MS subtype, as no cases of TN were observed among patients with primary progressive MS, the researchers concluded.

Testing and Treating Trigeminal Neuralgia in MS

A related review article published in 2019 in the Journal of Headache and Pain addressed diagnostic testing and treatment options for TN in people with MS.²

Giulia Di Stefano, MD, of Sapienza University in Rome, Italy, and colleagues reviewed data from studies published through 2018. TN in MS, they wrote, is characterized by “sudden, usually unilateral, brief, stabbing or electrical shock-like, recurrent pain with a distribution that is consistent with one or more divisions of the fifth cranial nerve.”² However, some patients with MS and TN report continuous, dull, burning, or tingling pain between these brief episodes.

Further, they noted, neuroimaging studies in people with MS have shown “a significant association between neurovascular compression and TN secondary to MS.” However, they wrote, “pharmacological treatment of TN secondary to MS is challenging owing to the poor tolerability of drugs and the lack of evidence-based information in the literature.” Data are limited mainly to small, open-label trials based on carbamazepine, lamotrigine, gabapentin, topiramate, misoprostol, or combination treatments.

Dr. Di Stefano and colleagues added that, while the effect of surgery on TN in people with MS has not been well studied, many individuals with MS have undergone procedures including percutaneous glycerol injection, balloon compressions, stereotactic radiosurgery, radiofrequency thermocoagulation, and microvascular decompression to manage TN. Evidence of the effectiveness of microvascular decompression in particular supports the potential role of neurovascular compression in TN among MS patients, they added.

Still, data on the long-term outcomes of MS patients after surgeries for TN are lacking, and the potential for adverse events suggests that surgery should be a last resort for refractory cases, the researchers wrote.