1131 - Cauda Equina Syndrome following multilevel spinal fusion for chronic back pain

A 68-year-old female with chronic radicular low back pain underwent multilevel thoracolumbar fusion and pelvic fixation. Intraoperatively, somatosensory evoked potentials abruptly decreased, and motor evoked potentials were absent distal to the knees bilaterally, although remained intact proximally. She immediately underwent posterior canal exploration, decompression, and fusion. Postoperatively, she had bilateral lower extremity flaccid paralysis with sensory loss, neurogenic bowel, and bladder dysfunction, leading to transfer to acute inpatient rehabilitation. Urinary retention was managed with timed voiding and intermittent catheterization. A lower motor neuron bowel program was initiated given absent anal sensation, deep anal pressure, and voluntary contraction, consisting of miralax, senna, colace, and enemas. Pain was managed with gabapentin, hydrocodone-acetaminophen, methocarbomol, topical agents, and home buprenorphine. At discharge, she had persistent lower extremity weakness but demonstrated improved confidence and functional independence, requiring supervision for ADLs and gait. Outpatient EMG showed diffuse lower motor neuron lesions consistent with cauda equina syndrome.

Discussions:

The cauda equina consists of lumbar and sacral nerve roots distal to the conus medullaris, responsible for motor and sensory innervation of the lower extremities and control of bowel, bladder, and perineal function. CES is a surgical emergency characterized by injury to these nerves, with potentially catastrophic functional consequences. Common etiologies include herniated disc, trauma, infection, hematoma, tumor, or stenosis. In this case, the etiology was likely multifactorial, including intraoperative trauma and possibly ischemia with a significant improvement in functional impairments following an acute inpatient rehabilitation admission.

Conclusions: CES is a rare but emergent diagnosis. This case highlights an atypical etiology/presentation and emphasizes the critical role of acute inpatient rehabilitation in improving independence, functional outcomes, and quality of life following CES.