Can someone with Cauda Equina Syndrome (CES) have normal Deep Tendon Reflexes (DTRs)?

Cauda Equina Syndrome and Deep Tendon Reflexes

Yes, a patient with Cauda Equina Syndrome (CES) can have normal deep tendon reflexes, especially in the early stages of the condition. 1

Clinical Features of CES and Relationship to Reflexes

• CES is primarily characterized by urinary retention (90% sensitivity), saddle anesthesia, bilateral radiculopathy, and bowel/bladder dysfunction 2
• Deep tendon reflexes may remain normal in early CES because:
  • CES affects the cauda equina nerve roots below the level of the spinal cord termination 3
  • The pathology primarily affects sensory and autonomic functions before motor reflexes in many cases 2
• A documented case shows CES can present with absent deep tendon reflexes, but this is not universal or required for diagnosis 1

Diagnostic Considerations for CES

• The true "red flags" for CES include:
  • Bilateral radiculopathy (bilateral radicular pain, sensory disturbance, or motor weakness) 4
  • New changes in bladder function with preserved control (hesitancy, poor stream, urgency) 4
  • Subjective and/or objective loss of perineal sensation 4
• Recent research (2024) shows that bilateral leg pain and absent bilateral ankle reflexes together have acceptable diagnostic utility for predicting radiologically confirmed cauda equina compression 5
• However, no single symptom or sign has high positive predictive value in isolation 2

Progression of CES and Reflex Changes

• CES typically progresses from early warning signs to late, irreversible symptoms 6
• Stages of CES progression:
  • Preclinical: Low back pain with only bulbocavernosus reflex and ischiocavernosus reflex abnormalities 7
  • Early: Saddle sensory disturbance and bilateral sciatica 7
  • Middle: Saddle sensory disturbance, bowel/bladder dysfunction, motor weakness, reduced sexual function 7
  • Late: Absence of saddle sensation, sexual function, and uncontrolled bowel function 7
• Deep tendon reflexes may remain normal in early stages and become abnormal as the condition progresses 7, 1

Clinical Implications and Management

• MRI is essential for all suspected cases of CES, regardless of reflex status 8
• Normal deep tendon reflexes should not rule out CES if other suspicious symptoms are present 2
• The British Journal of Neurosurgery emphasizes that CES is a clinical diagnosis that requires MRI confirmation of cauda equina compression 4
• Early intervention before progression to complete CES with retention is critical to prevent permanent neurological damage 8

Common Pitfalls to Avoid

• Relying on late "white flag" symptoms (including reflex changes) for diagnosis often results in permanent neurological damage 6
• Waiting for complete urinary retention before referral is a common pitfall, as it is a late sign 8
• Inadequate assessment can lead to missed diagnosis, particularly if clinicians expect all CES patients to have abnormal reflexes 2
• Delaying MRI when CES is suspected is a critical error, even if reflexes are normal 8