A case of cauda equina syndrome caused by a simple sneeze

Corresponding author: Doré DeBartolo, DO, Department of Family Medicine, Advocate Christ Medical Center, 4140 Southwest Highway, Hometown, IL 60456.

E-mail address: dore.debartolo@gmail.com.

Introduction

Low back pain with radicular symptoms is a common com- plaint. The typical treatment is a course of anti-inflamma- tory medication, physical therapy, and epidural spinal in- jections. Failure of these treatment modalities may then require the need for surgical decompression. Often, patients have had symptoms for many years. Although the preva- lence is relatively rare (approximately 4 in 10,000 patients with low back pain),1 it is an important diagnosis for the family physician to recognize.

‌Cauda equina, or “horse’s tail,” refers to the terminal por- tion of the spinal cord and roots of the spinal nerves beginning at the first lumbar nerve root. Cauda equina syndrome (CES) refers to compression of some or all of these nerve roots. CES is commonly associated with saddle anesthesia (loss of sensa- tion in perineal area); urinary retention; and bilateral lower extremity pain, numbness, and weakness. It may progress to paraplegia or permanent incontinence of either bowel or blad- der. Decreased rectal tone is a relatively late finding. Urinary incontinence is also a late finding as it is caused by overflow from urinary retention. The first case was reported in 1934 by Dandy,2 although in 1934 the concept was popularized by Mixter and Barr.3 The majority of patients have a history of chronic back pain (about 70%) versus 30% of patients who present with cauda equina syndrome as a primary manifesta- tion of their herniated disc.1 There are a number of factors that may cause a delay in the diagnosis of CES, which is a surgical emergency. The most common for a delay is the physician’s failure to consider the diagnosis.4 This case highlights an unusual outcome of CES after a sneeze in a patient with chronic back pain. Because this syndrome is so rare, many physicians may not consider it. This case illustrates the impor- tance of a very thorough physical examination and workup in any patient with an acute worsening of chronic back pain. The teaching points include a review of the literature and address physical examination, diagnosis, and treatment options.

Case summary

A 44-year-old female with a past medical history of hyper- tension, diabetes, and spinal stenosis presented to the emer- gency department with acute worsening of her low back ‌emergency could have easily been overlooked secondary to the chronicity of her back pain and the very mild inciting factor.

‌The patient underwent decompressive surgery within 48 hours of the onset of symptoms, and within 24 hours of presentation to the emergency department. She regained sensation in her legs within 24 hours after surgery, but upon discharge she still had saddle anesthesia; however, she was able to walk with the assistance of a walker. Nine months after surgery, she was able to walk with a cane and her back pain had completely resolved. She had no residual urinary incontinence; however, she had persistent anesthesia in the perineum and down the sides of her legs and feet.

In this case, the patient had a known diagnosis of spinal stenosis and herniated disc with stable lumbar radiculopathy that was treated for many years with epidural injections. The only inciting incident was a sneeze. This acute surgical

Discussion

Most often, CES arises from a massive midline disc herni- ation. However, other causes include spinal metastases, hematoma, epidural abscess, traumatic compression, acute transverse myelitis,1 is spinal stenosis, tumor,5 post epidural steroid injection,6 after traction or spinal manipulation,7 or as a postoperative complication.8

Delay in treatment of CES is most often caused by a delay in making the diagnosis.4 Physical examination of the patient with severe low back pain should include a rectal examination to assess anal sphincter tone and perineal sen- sation, as well as a post-void residual to assess for urinary retention. Urgent MRI should be done for a definitive diag- nosis.

Treatment of CES is surgical decompression; however, the literature reveals conflicting evidence about how soon it should be done. A meta-analysis by Ahn et al.9 of 332 cases suggested that surgery should be performed within 48 hours, but within that timeframe there is no significant difference in outcome. Another meta-analysis by Todd10 proved that treatment within 24 hours does have better outcomes than treatment within 48 hours. A prospective cohort study by Qureshi et al.11 showed no significant dif- ference between patient outcomes with respect to timing of surgery, but did note a significantly better outcome in pa- tients who were continent of urine at presentation compared with those who were incontinent. A retrospective literature review by Gleave and Macfarlane12 concluded that for pa- tients with complete lesions (patients with overflow incon- tinence), there is no benefit to urgent decompression; how- ever, urgent surgery remains indicated for incomplete lesions. Regardless of the conflicting evidence, it remains the standard of care to treat patients within 48 hours of the onset of symptoms.

In summary, low back pain is a very common complaint. Although CES is relatively rare, it is associated with a high morbidity if left untreated. The majority of patients with CES have chronic back pain; hence, it may be easy to overlook an acute change in pain or sensation or strength. It is crucial to perform a rectal examination and a post-void residual to evaluate for urinary retention in these patients, as well as urgent MRI to make, and not overlook, this crucial diagnosis.

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   ‌DeBartolo Cauda Equina Syndrome from a Simple Sneeze 29
   

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