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Updated: Sep 23, 2026
Comprehensive Autopsy Program for Individuals with Multiple Sclerosis
Published on: July 19, 2019
Linear pontine trigeminal root lesions in multiple sclerosis: clinical and magnetic resonance imaging studies in 5
I Nakashima1, K Fujihara, T Kimpara
1Department of Neurology, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan. inakashima@neurol.med.tohoku.ac.jp
Background:
Magnetic resonance imaging (MRI) is useful for demonstrating demyelinating lesions in patients with multiple sclerosis (MS). Magnetic resonance imaging studies show that MS lesions are generally not uniform in shape, size, or distribution. Linearly shaped lesions at the trigeminal root entry zone have been occasionally reported in single cases of MS, but, to our knowlege, the frequency and the clinical features of such patients have not been comprehensively characterized.
Objective:
To describe the frequency and the clinical and laboratory features of patients with MS who had linearly shaped lesions at the trigeminal root as seen on MRI.
Design And Setting:
A retrospective review of medical records and MRI films of Japanese patients with MS admitted to a university hospital and its affiliated hospital in Sendai, Japan.
Patients And Methods:
Brain MRI films of 74 consecutive Japanese patients with MS (51 females and 23 males) were studied retrospectively and the clinical and laboratory features of the patients with linearly shaped lesions at the trigeminal root were also investigated retrospectively.
Results:
Five patients (6.8%) were shown to have T1-weighted-hypointense, T2-weighted-hyperintense, nonenhanced linear lesions in the pons on MRI, and these were uniformly localized in the intramedullary portion of the trigeminal root. All of these patients had clinically definite MS and had various types of facial sensory disturbances, such as neuralgia (1 patient), hypesthesia (2 patients), or paresthesia (3 patients). No other clinical or laboratory feature was characteristic in these 5 patients.
Conclusions:
Linear pontine trigeminal root lesions were common in our patients with MS. They were associated with various facial sensory symptoms. Since similar lesions are formed in animal models of herpes simplex virus infection, further study is needed to clarify whether these MS lesions are virally induced.
Insights
Linear lesions in the trigeminal nerve are common in multiple sclerosis (MS) patients and can cause facial sensory issues. Further research is needed to determine if viral infections trigger these MS lesions.
Area of Science:
- Neurology
- Radiology
- Neuroimmunology
Background:
- Multiple sclerosis (MS) diagnosis relies on identifying demyelinating lesions via Magnetic Resonance Imaging (MRI).
- MS lesions typically vary in shape, size, and distribution.
- Linear lesions at the trigeminal nerve entry zone are infrequently reported in MS.
Observation:
- This study retrospectively reviewed 74 Japanese MS patients.
- MRI scans of patients with linear trigeminal root lesions were analyzed.
- Clinical and laboratory data of these patients were investigated.
Findings:
- Six-point-eight percent of MS patients exhibited linear, nonenhanced lesions in the pons, specifically at the trigeminal root entry zone.
- These lesions correlated with diverse facial sensory disturbances, including neuralgia, hypesthesia, and paresthesia.
- No other distinguishing clinical or laboratory features were identified in patients with these specific lesions.
Implications:
- Linear pontine trigeminal root lesions are a notable finding in Japanese MS patients.
- These lesions are associated with characteristic facial sensory symptoms.
- The potential viral etiology of these MS lesions warrants further investigation, particularly in light of similarities to animal models of herpes simplex virus infection.
