What are the key components of a physical exam in a patient with suspected spinal cord compression?

Key Components of a Physical Exam in Suspected Spinal Cord Compression

A thorough neurological examination is essential for patients with suspected spinal cord compression, focusing on motor strength, sensory changes, reflexes, and assessment of autonomic function.

Neurological Assessment

Motor Function

• Assess muscle strength in all extremities using the 5-point scale (0-5) to detect weakness, which is present in up to 71% of patients with spinal cord compression 1
• Evaluate for deteriorating gait, which occurs in approximately 67% of patients with spinal cord compression 2
• Test gait when possible, as impaired gait may be present even in patients without obvious motor or sensory deficits 1

Sensory Function

• Evaluate for sensory changes or numbness in extremities, which are common findings in spinal cord compression 3
• Assess for sensory level (dermatomal distribution of sensory loss) to help localize the level of compression 3
• Note that approximately 10% of patients with spinal cord compression may have normal sensory function 2

Reflex Testing

• Check deep tendon reflexes in all extremities, noting hyperreflexia above and hyporeflexia below the level of compression 3
• Test for pathological reflexes such as Babinski sign, which may indicate upper motor neuron involvement 3
• Assess for absent lower limb reflexes, which can be a sign of cauda equina syndrome 3

Autonomic Function Assessment

Bladder and Bowel Function

• Evaluate for urinary retention or incontinence, which occurs in approximately 48% of patients with spinal cord compression 2
• Note that 35% of patients with spinal cord compression may have no sphincter disturbance 2
• Assess for perianal sensation and anal sphincter tone, especially when cauda equina syndrome is suspected 3

Pain Assessment

Back Pain Characteristics

• Evaluate for local and/or radicular pain, which is present in 90% of patients with malignant spinal cord compression 3
• Assess for pain that worsens with recumbency, Valsalva maneuver, or movement 3
• Note that back pain is the most common physical finding in patients with cauda equina syndrome 3

Special Considerations

Red Flags for Specific Etiologies

• Check for fever, which may suggest infectious etiology such as epidural abscess 3
• Assess for signs of spinal instability such as severe pain with minimal movement 3
• Consider risk factors such as history of cancer, IV drug use, diabetes, or immunosuppression 3

Comprehensive Approach

• Document the temporal progression of symptoms, as this helps determine urgency of intervention 4
• Remember that presentations can be subtle with absent or unilateral motor and sensory deficits 1
• Note that misdiagnosis of spinal cord compression is common (29% in one study), highlighting the importance of a thorough examination 1

Examination Pitfalls to Avoid

• Do not rely solely on motor and sensory testing, as 24% of patients may have no motor or sensory deficit 1
• Avoid missing unilateral findings, which occur in approximately 23% of patients with spinal cord compression 1
• Do not overlook gait assessment, which may reveal abnormalities even when other neurological findings are normal 1
• Remember that the absence of sphincter dysfunction does not rule out spinal cord compression 2

The physical examination findings should guide appropriate and timely imaging, with MRI being the preferred modality for suspected spinal cord compression due to its excellent sensitivity and specificity 3.