Central trigeminal involvement in multiple sclerosis using high-resolution MRI at 3 T

Trigeminal neuralgia and sensory disturbance is common in multiple sclerosis (MS). Recent literature suggests that signal abnormalities in the cisternal trigeminal nerve and pontine root entry zone are seen in approximately 3% of MS patients, using conventional diagnostic MRI. The objective of this study was to determine the prevalence of trigeminal lesions using high-resolution MRI at 3T. Forty-seven patients with clinically definite MS, chosen at random from the outpatient population of a neuroscience centre underwent MRI on a Siemens 3T Trio machine. Three 3D sequences of T2 TSE (turbo spin echo), T2 FLAIR (fluid attenuated inversion recovery) and T1 IR (inversion recovery) were acquired in the coronal plane. The sequences were of contiguous 1 mm slices with in-plane resolution of up to 0.5 mm by 0.5 mm. Images were read by both a neurologist and a neuroradiologist. Any clinical history of trigeminal symptoms was determined for all subjects. The results showed that 11 patients (23%) had high signal in the trigeminal root entry zone and either the trans-cisternal nerve or pontine nucleus; example images are given. MRI changes did not correspond to clinical symptoms (chi square probability 1.000). The study concludes that high-resolution MRI at 3T yielded a high prevalence of detectable trigeminal abnormality in the MS sample studied. MRI involvement did not correspond to trigeminal symptoms.Both facial pain (including trigeminal neuralgia) and non-painful facial sensory disturbance are routinely encountered in patients with multiple sclerosis (MS). Previous studies suggest that the prevalence of trigeminal lesions is between 3% and 7% 1, 2], and such lesions may or may not be related to clinical symptoms 1–5]. The relationship between trigeminal sensory symptoms and trigeminal lesions remains unclear. The use of thin, contiguous slices and higher field strength, which improves signal to noise ratio (SNR), may yield greater detection of abnormalities 6–8]. A prospective study was therefore undertaken to determine the prevalence of central trigeminal lesions in MS, using high-resolution MRI at 3 T, and the relation between the presence of lesions and facial sensory symptoms.