Context: Elsberg Syndrome (ES) is a rare syndrome associated with acute or subacute infections, often accompanied by myelitis confined to the lower spinal cord, in addition to paresthesia, weakness in the lower limbs, urinary retention, constipation, among others. It is a self-limiting disease, manifested through primary HSV type 2 infection, especially in immunocompetent patients. Case report: Male patient J.F.C., 58 years old, reports a sudden paresthesia in the lower limbs without other associated clinical conditions for approximately 2 months that progressed to paresis, cramps and loss of sphincter control. Admitted to the General Hospital of Palmas, Tocantins on 02/18/2020 with suspicion of Peripheral Polyneuropathy that was discarded after electroneuromyography. Imaging exams without relevant findings. After a week of hospitalization, multiple lesions appeared in the region of the lower third of the dorsum and buttocks, compatible with lesions by HSV (herpes simplex virus) and the diagnosis of ES was concluded. At the moment, he was undergoing treatment with acyclovir and awaiting the evolution of the condition. Conclusion: ES is an often unrecognized cause of lumbosacral radiculitis, which is why it is important to establish as a diagnosis differential. The analysis of CSF, PCR and MRI confirm the diagnosis in cases of HSV-2 lumbosacral radiculomyelitis. CSF usually reveals a lymphocytic pleocytosis and a slight elevation of proteins.