Severe headache with eye involvement from herpes zoster ophthalmicus, trigeminal tract, and brainstem nuclei

A 43-year-old female presented with severe sharp stabbing right-sided periorbital and retroorbital area headache, dull-aching unilateral jaw pain, eyelid swelling, ptosis, and tearing of the right eye but no rash. The pain episodes lasted five minutes to one hour and occurred 10-15 times per day with unremitting milder pain between the attacks. She later developed an erythematous maculopapular rash over the right forehead and therefore was treated with antivirals. MRI performed one month after the onset revealed small hypersignal-T2 in the right dorsolateral mid-pons and from the right dorsolateral aspect of the pontomedullary region to the right dorsolateral aspect of the upper cervical cord, along the course of the principal sensory nucleus and spinal nucleus of the right trigeminal nerve. No definite contrast enhancement of the right brain stem/upper cervical cord was seen. Orbital imaging showed no abnormality of bilateral optic nerves/chiasm, extraocular muscles, and globes. Slight enhancement of the right V1, V2, and the cisterna right trigeminal nerve was detected. Our findings support the hypothesis of direct involvement by virus theory, reflecting rostral viral transmission along the gasserian ganglion to the trigeminal nuclei at brainstem and caudal spreading along the descending tract of CN V.