Case Presentation: 52 years old male with no significant past medical history presented to the hospital with back pain within few days to leg tingling ascending to his nipple level with weakness and inability to walk. In the ED, he was noted to have myelopathic changes on exam from T2-3 level down with hyperreflexia in bilateral lower extremities and upgoing Babinski reflex. His non-con MRI of complete spine was negative for cord compression with a small T3 superior end plate fracture with negligible height loss and no retropulsion. Patient was complaining of constipation and inability to void despite leaky urine so a foley catheter was placed along with a urology consult and repeat MRI with contrast of cervical and thoracic spinewith no abnormal enhancement. Lumbar puncture was eventually done which was positive for HSV-1 Polymerase chain reaction (PCR). Otherwise, it was negative for varicella-zoster, West Nile, syphilis, Lyme, fungal culture. The patient was noted to have mild elevation of liver enzymes so acute hepatitis panel was obtained including cryptococcus, HIV and syphilis which were negative in the serum. Patient was started on IV acyclovir with some improvement in motor strength but no improvement in sensation. The patient was discharged on IV acyclovir for a complete course of 3 weeks to acute rehab where he sustained motor and sensation improvement. Patient continuous to follow with outpatient physical therapy since.

Discussion: HSV myelitis has previously been reported to be a form of acute ascending necrotizing myelitis. HSV -2 related myelitis has been reported in multiple case reports in the past but on our literature review there have been only 2 cases of HSV-1 related myelitis. Most common presentation is gradually ascending sensorimotor disturbances of lower extremities along with urinary disturbances although patients can also present with non-ascending myelitis. MRI of the spine can be false negative and thus PCR of spinal fluid remains the gold standard of diagnosis.

Conclusions: We present a rare case of HSV-1 myelitis. HSV-2 related myelitis is a well known entity but our case highlights a rare HSV-1 related myelitis. Furthermore CSF testing remains the gold standard diagnostic technique and MRI of the spine can be false negative.