Early Deficits of Cauda Equina Syndrome: A Case Study

A case of leg pain, nausea, and malaise
A case of leg pain, nausea, and malaise
A young man is diagnosed with cauda equina syndrome on his third visit to an emergency department. Early and late CES signs/symptoms are discussed in this case study

The following article is a part of conference coverage from the American Academy of PAs 2021 Conference (AAPA 2021), held virtually from May 23 to May 26, 2021. The team at the Clinical Advisor will be reporting on the latest news and research conducted by leading PAs. Check back for more from AAPA 2021


The true red flags of cauda equina syndrome (CES) are the early neurologic deficits that patients present with, said Courtney Hart, PA-S, in a poster presentation at the American Academy of PAs 2021 Conference (AAPA 2021).

“Familiarity with uncharacteristic clinical presentations of CES, including unilateral lower extremity numbness and weakness, can help clinicians to be more inclined to promptly order lumbar spinal imaging and neurosurgical consult,” said Hart, who is a student at Quinnipiac University’s PA program in Hamden, Connecticut (Table).

Table. Cauda Equina Syndrome Signs and Symptoms

Early stage CES signs/symptoms
Progressive neurological deficits in the lower extremities
Impaired bladder or urethral sensation, hesitance, poor stream with retained control of micturition
Late stage CES signs/symptoms
Impaired perineal sensation
Impaired anal tone
Urinary retention or incontinence
Fecal incontinence
Perianal anesthesia

Cauda Equina Syndrome Revealed

A 22-year-old obese Hispanic man presents to the emergency department (ED) with atraumatic left calf pain radiating to the inner thigh, which began 1 day prior. On initial presentation, he denies recent trauma, lumbar back pain, radiculopathy, and lower extremity weakness. His physical examination is unremarkable for calf erythema, edema, or tenderness to palpation, and his neurologic examination is normal and without sensory deficits. He is diagnosed with myalgia based on clinical presentation and discharged with a prescription for naproxen and cyclobenzaprine as needed.

He returns to the ED without benefit. On his third trip to the ED, the patient presents with progressive symptoms consisting of bilateral calf cramping and weakness, lower back pain, numbness, tingling, urinary incontinence, and saddle anesthesia. Pertinent findings on examination include lumbar paraspinal muscle tenderness, positive straight leg raise, inability to stand or walk, and perianal anesthesia on rectal examination.

“A simple review of systems provided answers that immediately made me realize something more urgent was going on when, to my surprise, the patient revealed that he did experience 1 episode of urinary incontinence and felt numbness in his groin area,” Hart said. Urinary retention was quickly confirmed via bladder ultrasound. His complete blood count and electrolytes were within normal limits and high sensitivity D-dimer testing was negative.

Progressive Symptoms Heighten Concern

Progression of clinical symptoms was concerning for spinal cord compression and magnetic resonance imaging (MRI) of the lumbar spine was necessary. However, on-site MRI was not available at the community hospital.

“The question raised was should we immediately transfer the patient to a higher-level facility with MRI capabilities or obtain a lumbar computed tomography (CT) scan at the community hospital before the transfer?” Hart said. Although symptoms such as urinary incontinence and perianal paresthesia supported a diagnosis of CES, it was decided that a confirmatory CT scan would be helpful to the transferring facility so that urgent neurosurgical intervention could be performed upon arrival. “My research supported that CT lumbar spine does have a role in screening for CES in community hospitals, as well as for ruling out CES when clinical suspicion is low. The CT scan was ordered,” Hart explained.

CT image findings revealed a large central disc osteophyte protrusion with multifactorial degenerative changes and congenitally short pedicles at L4-L5 resulting in suspected severe central canal stenosis and compression of the CES nerve roots. The bladder and bilateral ureters were distended.

The patient was urgently transferred to the university hospital’s neurosurgical spine department for further evaluation and treatment.

Practice Pointers for ED Clinicians

“Looking back, I think the patient’s first visit to the ED did not warrant further workup based on clinical presentation and pertinent negatives. However, when the patient returned 2 days later with progression of the same symptoms and bilateral involvement, further consideration into other possible diagnoses would have been useful. It was easy to say this was simply worsened myalgia at the time, and perhaps the patient’s young age did not heighten suspicion for something more serious. With the diagnosis of CES that we now know, this case highlights progressive signs and symptoms of the syndrome that began with only unilateral calf pain,” stated Hart.

Fast facts about CES

  • Cauda equina syndrome is a collection of symptoms that include sciatica, saddle anesthesia, urinary retention, and sphincter dysfunction. Diagnosis is achieved through physical examination and lumbar imaging.
  • True red flags of CES are the early neurologic deficits. These red flags should prompt emergent lumbar spine imaging and neurosurgical consult.
  • Familiarity with uncharacteristic clinical presentations of CES, including unilateral lower extremity numbness and weakness without sphincter involvement or saddle anesthesia, will help clinicians to recognize premonitory features of CES.
  • For community hospitals without access to MRI, a CT scan should be obtained before transferring the patient.
  • Consider CES when a patient presents with progressive neurologic deficits in the lower extremities.

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Hart C, Lavender Z. Cauda equina syndrome presenting as unilateral calf myalgia in a 22-year-old male. Poster presented at: American Academy of PAs 2021 Conference; May 23-26, 2021. Poster 222.

This article originally appeared on Clinical Advisor