What is the initial approach to a patient presenting with numbness?

Initial Approach to Numbness

For a patient presenting with isolated numbness, immediately determine the distribution pattern (unilateral vs. bilateral, focal vs. diffuse) and perform urgent stroke assessment if unilateral, as this carries a 10% risk of completed stroke within the first week. 1

Immediate Emergency Assessment

Unilateral Numbness (Face, Arm, or Leg)

• Check bilateral radial pulses and blood pressure in both arms immediately to differentiate stroke from acute arterial occlusion 1
• A blood pressure difference >20 mmHg between arms confirms significant arterial compromise 1
• Perform Cincinnati Prehospital Stroke Scale: assess for facial droop, arm drift, and abnormal speech 1
• Assess the "6 P's" of acute limb ischemia if peripheral: Pain, Pallor, Pulselessness, Paresthesias, Poikilothermia (cool limb), Paralysis 1

Urgent Neuroimaging for Unilateral Symptoms

• Brain MRI with diffusion-weighted imaging is the preferred initial imaging and must be performed immediately 1
• If MRI unavailable, perform CT head without contrast to rule out hemorrhage 1
• The combination of facial numbness with unilateral symptoms has 72% probability of stroke when accompanied by facial weakness or speech disturbance 1

Bilateral Hand/Finger Numbness

Critical Diagnostic Considerations

• Consider cervical spine pathology first, particularly central cord syndrome or cervical spinal cord injury without fracture/dislocation (SCIwoFD) 2
• Central cord syndrome classically presents with greater upper extremity weakness than lower extremity involvement, with bilateral hand numbness and burning dysesthesias in forearms 2
• Obtain cervical spine MRI if bilateral hand numbness is accompanied by burning dysesthesias or any lower extremity symptoms 2

Systematic Evaluation

• Test temperature/pinprick sensation (small fiber) and vibration with 128-Hz tuning fork (large fiber function) 2
• Assess for diabetic peripheral neuropathy, which typically presents in "stocking-and-glove" distribution starting distally 2
• Consider other causes: thyroid dysfunction, vitamin deficiencies, and toxic exposures 2

Cauda Equina Syndrome (Red Flag Presentation)

If numbness involves perianal or saddle region, or is accompanied by bladder/bowel dysfunction, this represents cauda equina syndrome requiring emergency MRI. 3

• Back pain with radicular symptoms, weakness in lower limbs, sensory changes, or absent lower limb reflexes are associated symptoms 3
• MRI lumbar spine without IV contrast is the imaging study of choice for suspected cauda equina syndrome 3
• A single 3-D heavily T2-weighted fat-saturated sequence protocol can be used as a rapid, highly sensitive tool in the emergency department 3

Treatment Based on Etiology

For Peripheral Neuropathy with Numbness

• Duloxetine is recommended as first-line pharmacologic treatment for peripheral neuropathy with numbness and tingling 3, 2
• Offer physical activity for neuropathy symptoms 3, 2
• Acetaminophen, NSAIDs, and acupuncture can be offered for associated pain 3, 2

For Confirmed Stroke/TIA

• Dual antiplatelet therapy (aspirin + clopidogrel 75 mg) should be initiated for the first 21 days in patients with symptomatic carotid stenosis not undergoing revascularization 1
• Perform carotid ultrasound to identify extracranial carotid stenosis >70% requiring carotid endarterectomy 1

Common Pitfalls to Avoid

• Do not dismiss isolated sensory symptoms as benign—isolated hemibody sensory loss still represents high stroke risk 1
• Do not delay imaging for bilateral hand numbness if accompanied by any lower extremity symptoms, as this may indicate cervical cord pathology requiring urgent neurosurgical consultation 2
• Do not attribute all bilateral numbness to peripheral neuropathy without first excluding central causes 2
• The highest stroke risk occurs within the first 48 hours of symptom onset 1