# Concurrent Longitudinal Extensive Transverse Myelitis and Leptomeningitis in West Nile Virus: A Report of a Rare Case

## TL;DR

This paper reports a rare case of West Nile virus causing both spinal cord and brain lining inflammation, highlighting the disease's non-specific symptoms and diagnostic challenges.

## Contribution

The novelty lies in documenting a rare concurrent occurrence of LETM and leptomeningitis in a West Nile virus case.

## Key findings

- The patient showed MRI evidence of spinal cord inflammation from T10 to L1 and leptomeningeal enhancement.
- Partial response to intravenous immunoglobulin therapy was observed, but chronic nerve damage persisted.
- The case underscores the non-specific clinical presentation of West Nile neuroinvasive disease.

## Abstract

Here we report a rare case with concurrent longitudinal extensive transverse myelitis (LETM) and leptomeningitis due to West Nile virus infection. A 47-year-old man initially presented with a six-day progressive, intermittent low-grade fever, headache, diplopia, malaise, myalgia, lower back pain, and difficulty walking that developed into progressive asymmetric paralysis. Initial lab work was notable for mild lactic acidosis and hyperCKemia. Brain MRI with contrast demonstrated small foci of leptomeningeal enhancement in the cerebellum, pons, medulla, and right CN VI at the cisternal segment. MRI of the spine was remarkable for edema in the spinal cord extending from T10 to L1 with diffuse enlargement of the cord contour at T11 to L1 and subtle enhancement of nerve roots within the thecal sac and cauda equina regions. The patient responded partially to five-day intravenous immunoglobulin therapy (total dose, 2 g/kg). Electromyography four months after the onset of symptoms also showed chronic reinnervation with active denervating features in thoracolumbar myotomes. Clinically, this case highlights the ill-defined and non-specific nature of the presentation of West Nile neuroinvasive disease. It can pose a diagnostic challenge for clinicians and, if unrecognized, is associated with significant morbidity and mortality in older and compromised individuals.