When infection mimics cauda equina syndrome: a cautionary tale.

A 63-year-old man presented to the emergency department with low back pain, perineal and genital numbness, together with bilateral lower limb paraesthesia and urinary retention. He was admitted under the orthopaedic service for investigation of suspected cauda equina syndrome. Magnetic resonance imaging of his spine did not reveal any evidence of cauda equina compression. Magnetic resonance imaging of his brain demonstrated nonspecific multiple hyperintensities in the right frontotemporal and left temporo-occipital regions. Computed tomography of his chest, abdomen, and pelvis did not identify any evidence of malignancy. Cerebrospinal fluid from a lumbar puncture showed a high leucocyte count (predominantly lymphocytes). Viral cerebrospinal fluid polymerase chain reaction was positive for varicella zoster virus. A diagnosis of varicella zoster virus myeloradiculitis (Elsberg syndrome) was established and the patient was treated with intravenous aciclovir. Unfortunately, the patient succumbed to a devastating intracerebral haemorrhage during his inpatient stay, probably due to vasculopathy from the underlying varicella zoster virus infection. This case describes a rare infectious mimic of cauda equina syndrome. Elsberg syndrome is an infectious syndrome characterised by bilateral lumbosacral myeloradiculitis, with varicella zoster virus being a well-recognised aetiological agent. We discuss the relevant literature in detail and identify the key, cautionary lessons learned from this case.