Elsberg syndrome is sacral radiculitis caused by a viral infection, most commonly herpes simplex virus type 2 (HSV-2) - whether a primary infection or a reactivation. The typical patient is a young sexually active woman presenting wtih acute transient urinary retention and sensory lumbosacral symptoms, such as dull pain in anorectal region, paresthesias, loss of sensation or flaccid paresis of leg muscles. Patients can also have constipation or erectile dysfunction.
The presence of inguinal lymphadenopathy and/or anogenital rash can be important clues but are not necessary for diagnosis. CSF may show mild to moderate pleocytosis, with a mild elevation in proteins. Herpes PCR in the CSF may be positive as well. The MRI may show varying degrees of root or lower spinal cord edema with hyperintensity of T2-weighted images.
In immunocompetent patient, the disease usually self limiting, usually resolving in 4-10 days, but can be progressive and ascending in patients with immunocompromise, such as HIV or cancer. Antiviral treatment may shorten the duration of illness in cases with confirmed herpes, either oral or IV.
References
Eberhardt O, K ker W, Dichgans J, Weller M. HSV-2 sacral radiculitis (Elsberg syndrome). Neurology 63(4), 24 August 2004, 758-759
