Herpes zoster ophthalmicus and the mesencephalic nucleus. A neuropathological study.

The ganglion Gasseri and the brainstem were examined in three old patients with herpes zoster without predisposing diseases with special reference to the mesencephalic trigeminal nucleus. The primary lesions in the semilunar ganglion vary with the length of the course. Secondary changes in the brainstem were as expected from pons to the second cervical segment of the cord. Besides, we observed degeneration, inflammation and glial nodules in the mesencephalic trigeminal nucleus in two patients. According to Brodal this nucleus presumably corresponds to the semilunar and spinal ganglia. As herpes zoster virus is prone to attack the sensory nuclei our findings support this hypothesis.