A 61-year-old woman had five episodes of myelitis and was diagnosed as multiple sclerosis (MS). She had an erup- tion on her left lower lip and the diagnosis of herpes labialis was confirmed by a dermatologist (Picture 1a). Sensory dis- turbance in the left mandibular nerve region was observed. Brain MRI revealed a T2-hyperintense linear lesion along the left intramedullary trigeminal nerve root (Picture 1b). This patient was infected with HSV confirmed by ELISA. We previously reported 5 patients with MS who had pe- culiar MRI lesions along the pontine intramedullary trigemi- nal nerve root with various ipsilateral facial sensory mani- festations (1). We supposed that those lesions might have been virally induced because they were similar to demyeli- nating lesions induced by experimental inoculation of HSV on the corneas of mice (2). The present patient may be a rare example of clinical manifestations of reactivated HSV in both proximal and distal portions of trigeminal nerve. The authors state that they have no Conflict of Interest (COI). Acknowledgement We thank Drs. Ohito Tano, Tatsuro Misu, Masashi Aoki, and Kazuo Fujihara for useful discussion. We also thank Mr. Brent Bell for reading our manuscript.
1. Nakashima I, Fujihara K, Kimpara T, Okita N, Takase S, Itoyama Y. Linear pontine trigeminal root lesions in multiple sclerosis: clinical and magnetic resonance imaging studies in 5 cases. Arch Neurol 58: 101-104, 2001.
2. Itoyama Y, Sekizawa T, Openshaw H, Kogure K, Goto I. Early loss of astrocytes in herpes simplex virus-induced central nervous system demyelination. Ann Neurol 29: 285-292, 1991.