[A case with trigeminal herpes zoster manifesting a long lesion of the spinal trigeminal nucleus and tract on MR T2-weighted image].

We reported a 53-year-old man with the right trigeminal herpes zoster with preceding neuralgia (preherpetic neuralgia) in the right upper cervical nerve area. He developed dysesthesia and scapular pain in the right second cervical nerve area. 5 days later, herpes zoster emerged in the area of the right maxillary division of trigeminal nerve. Furthermore, he developed paralysis on the right facial muscle on the 12th day after the onset of scapular pain. Neurological examination revealed decrease in superficial sensation accompanied by pain and dysesthesia in the areas innervated by the right maxillary division of trigeminal nerve and the right second cervical nerve, and the right peripheral facial nerve palsy. Any rash was not observed in the right second cervical nerve area throughout the course. The cerebrospinal fluid showed a mild mononuclear pleocytosis. The antibody titer for varicella zoster virus (VZV) was elevated in both cerebrospinal fluid and blood serum. T2-weighted magnetic resonance (MR) image revealed a continuously long high-signal lesion corresponding to the right spinal trigeminal nucleus and tract, extending from the lower pons to the second cervical segment of the spinal cord. This lesion could have resulted from a centripetal migration of VZV from the Gasser ganglion to the spinal trigeminal nucleus and tract, which was probably related to the preherpetic neuralgia in the upper cervical nerve area without rash.