Case of the Month

				Using the search form

To view this article in PDF form, click here.

Jennica E. N. Cornine, PA-C

Jennica Cornine works in the Department of Emergency Medicine, Medical Center of Central Georgia, Macon. Mrs. Cornine graduated from the Medical College of Georgia in 2007. She has indicated no relationships to disclose relating to the content of this article.

CASE

The patient is a 51-year-old female who presented to the emergency department (ED) via ambulance with a 1-month history of progressive lower back pain that had worsened over the previous 3 to 4 days. She was now unable to walk. She rated her pain as 10/10 and said it radiated down both legs, but the left more than the right. General movement, especially attempting to sit up from a supine position, exacerbated the pain. She described having paresthesia in her lower extremities (LE), as well as saddle anesthesia. The paresthesia was more intense on the left side, with decreased sensation from external stimuli. She admitted to urinary incontinence for 24 hours but denied fecal incontinence. She denied any recent falls or trauma to her lower back. The patient had taken oxycodone, 80 mg, and morphine liquid, 2 mg by mouth, but her symptoms were not alleviated.

History The patient had a hysterectomy 12 years ago for uterine carcinoma. Five years ago, she was found to have metastatic disease to her lumbar spine that was treated with radiation therapy and systemic chemotherapy. She underwent debulking surgery and more chemotherapy 1½ years ago to treat a second relapse. This surgery was followed with a fusion of L3 to L5 and L5-S1 diskectomy. Anastrozole (Arimidex) therapy had been initiated 1 week earlier, but the patient was unable to tolerate the drug after 3 days.

Physical examination The patient was awake, alert, and oriented. Vitals signs were all within normal limits. Heart rate and rhythm were regular. Lungs were clear to auscultation. A well-healed surgical scar in the lower lumbar region showed no erythema, hematomas, or tenderness to palpation. No step-offs or deformities were noted. No hemorrhoids, masses, or stool in the rectal vault were noted. Sphincter tone was diminished, and perianal anesthesia was present. CN II through VII were grossly intact. Upper extremity strength was 5/5 with good equal bilateral hand-grip strength. Bicep and tricep deep tendon reflexes (DTRs) were 2+ bilaterally. The patient was bilaterally unable to perform active hip or knee flexion/ extension, dorsiflexion, or plantar flexion. She also was unable to tolerate appropriate positioning to assess LE DTRs. Clonus and Babinski’s sign were negative. In the left LE, sensation with external stimulation was diminished compared to the right LE.

WHAT IS YOUR DIAGNOSIS?

Exacerbation of chronic lower back pain
Cauda equina syndrome (CES)
Prolapsed lumbar disc
Conus medullaris syndrome (CMS)

DISCUSSION

The patient had the classic signs and symptoms of CES. The conus medullaris forms the tapered end of the spinal cord, terminating at the L1 or L2 level. Extending from the conus medullaris are nerve roots from L1 through Co1 that look like a horse’s tail, giving it the name cauda equina. CES and CMS can be difficult to differentiate because both have similar causes; however, patients with CMS present with upper and lower motor neuron (MN) dysfunction. Upper MN dysfunction manifests as muscle weakness along with spasticity, Babinski’s sign, and hyperreflexia.

CT of the lumbar spine demonstrated diffuse left paraspinal soft tissue prominence extending from the L1-2 disk to the L4 vertebral body with suspected intraspinal involvement (see Figure 1). Thecal encroachment and stenosis were also suspected.

Treatment Diagnosis by CT/myelography and/or emergent MRI is essential when CES is suspected. Prior to confirmation, IV corticosteroids should be initiated.¹ Neurosurgical consultation is required to evaluate for urgent decompression.²

Our patient was given dexamethasone (Decadron), 10 mg IV initially, then 4 mg IV every 4 to 6 hours. We attempted pain control with both IV morphine and hydromorphone (Dilaudid). She refused emergent MRI secondary to claustrophobia. The patient was admitted, but she was determined not to be a surgical candidate and had exhausted other treatment options. She elected to receive palliative care and was discharged home under hospice.

Comments Lower back pain is a common complaint in the ED. An appropriate evaluation is essential for “red flags” including bladder and bowel dysfunction, trauma, cancer, recent spine instrumentation, and unrelenting pain.^1,2 A thorough examination is warranted when red flags are present. CES is a neurologic emergency with significant morbidity. Attention to red flags, a high index of suspicion, and prompt intervention will ensure diagnostic accuracy and improve outcomes. JAAPA

Erich Fogg, PA-C, MMSc, department editor

REFERENCES

1. Shapiro S. Medical realities of cauda equina syndrome secondary to lumbar disc herniation. Spine. 2000;25(3):348-352.

2. Arce D, Sass P, Abul-Kadoud H. Recognizing spinal cord emergencies. Am Fam Physician. 2001;64(4):631-638.