Trigeminal Neuralgia in Multiple Sclerosis Patients: Short Case Series

Objectives*
According to International Classification of Headache Disorders third edition (ICHD-3), trigeminal neuralgia
(TN) attributed to multiple sclerosis occurs in 2-5% of patients with multiple sclerosis (MS). TN is severe facial
pain due to malfunction of the 5 th cranial nerve. MS is a chronic demyelinating disease of central nervous
system. In some patients’ neurovascular conflict (NVC) of the trigeminal nerve root coexist with pontine plaque
at the root entry zone (REZ) determining condition as “double crush” phenomenon.
A 50- and 57-year-old females presented to the clinic with a 9- and 7-year history of right-side TN. Both patients
were undergoing MRI scan and electrophysiological study – blink reflex. The first female presented with normal
blink reflex, but the second case blink reflex indicated relatively longer R1 latency on the right side. In the 3D
CISS thin-slice T2 series, a loop of the right superior cerebellar artery is observed compressing the nerve, but
more pronounced in-patient No. 2. Additionally, both patients exhibit a lesion at the level of the pons in the
FLAIR sequence, suggesting a possible “double crush” phenomenon.
Neurovascular conflict diagnosis requires an in-depth understanding of the clinical aspects of neuroanatomy,
neurophysiology, and clinical aspects of cranial nerve dysfunction. Limited data on microvascular decompres-
sion for MS-related TN, new studies are needed. 3D FIESTA, CISS and MRI angiography sequences are the most
sensitive tools available to radiologists today, allowing optimal detection of cranial nerve root entrance area of
vascular compression. To increase the accuracy of diagnosis of neurovascular conflict, we need information
from more advanced neuroimaging techniques, radiologists need to take a systematic approach to imaging and
carefully apply the recommended criteria and to reduce false-negatives and false-positives reports.