Case Presentation: A 32-year-old female with a past medical history of migraines, anxiety, and depression presented to the emergency department with complaints of bilateral leg pain and urinary retention. Two weeks prior, she started experiencing urinary frequency and was started on nitrofurantoin at an urgent care center due to concern for a UTI. She also noticed new genital lesions around this time and had a positive NAAT test for HSV-2.Despite completing treatment with nitrofurantoin, the patient continued experiencing worsening dysuria and leg pain. It was suspected her symptoms were due to continued HSV-2 infection so she presented to the ED for further workup of her symptoms. Head CT and MRI brain showed no acute intracranial findings, but MRI L-spine showed extraforaminal enhancement and edema-like signal within all the lumbosacral nerve roots [Figure 1]. Although Kernig and Brudzinski sign were negative on physical exam, an LP was obtained as there was increased suspicion for HSV meningitis. The patient’s CSF studies were within normal limits, and the meningitis panel was negative. CSF culture showed no evidence of polymorphonuclear neutrophils. The patient was started on IV acyclovir and methylprednisolone for Elsberg syndrome. She completed five days of IV acyclovir and methylprednisolone treatment and was discharged on an oral prednisone taper and home IV acyclovir infusions to complete 14 days of treatment. She reported complete resolution of urinary symptoms and sacral pain following completion of the acyclovir course.
Discussion: Elsberg syndrome likely accounts for 5-15% of patients with cauda equina syndrome [1]. The etiology is most commonly due to Herpes Zoster Virus 2 (HSV-2) reactivation in sensory neurons, and sexually active women are preferentially affected [2]. However, physicians often leave out Elsberg syndrome in the differential diagnosis of acute cauda equina syndrome and do not perform HSV testing to facilitate definitive diagnosis. As a result, Elsberg syndrome is underreported. While Elsberg syndrome is usually self-limited, it may leave some degree of permanent neurologic deficit and even death if left untreated3. Confirmation of the causative virus is not required in mild cases, as early treatment is effective even in cases without a definitive viral cause. Treatment consists of 10-21 days of acyclovir, which has been shown to decrease pain and improve symptoms. Oral steroid tapers or high dose IV steroids can also help shorten the duration of symptoms [3].
Conclusions: Because Elsberg syndrome is rarely reported and has a highly variable clinical presentation, it often goes unrecognized. A high degree of clinical suspicion should be deployed when diagnosing patients with bilateral lumbosacral radiculitis, as early detection and treatment of Elsberg syndrome prevents long term morbidity.
