What are the next steps for a patient experiencing numbness in the right forearm and blurred vision?

Immediate Emergency Evaluation for Suspected Acute Stroke

This patient requires immediate activation of emergency medical services (EMS) and transport to a designated stroke center—the combination of unilateral numbness and blurred vision represents a high-probability acute stroke until proven otherwise, with a critical time window for intervention. 1, 2

Why This is a Medical Emergency

The simultaneous presentation of right forearm numbness and blurred vision creates a constellation of symptoms that strongly suggests acute cerebrovascular compromise. Patients presenting within 48 hours with unilateral numbness are at HIGH RISK for recurrent stroke with a 10% risk of completed stroke within the first week, with highest risk in the first 48 hours. 2 The addition of visual disturbances increases the probability of stroke to 72% when combined with other neurological deficits. 1

Immediate Actions Required

Prehospital Management

• Activate EMS immediately with notification that this is a suspected stroke for high-priority response. 1
• EMS personnel should perform the Cincinnati Prehospital Stroke Scale assessing facial droop, arm drift, and abnormal speech—if any one is abnormal, stroke probability is 72%. 1
• Provide supplementary oxygen only if oxygen saturation is less than 94%. 1
• Do not treat elevated blood pressure in the prehospital setting unless systolic BP is less than 90 mm Hg. 1

Transport Destination

Direct transport to a designated stroke center with capacity for advanced imaging and thrombolytic therapy on-site is mandatory, with prehospital notification to activate the stroke team. 1

Emergency Department Evaluation Protocol

Immediate Imaging (Within Minutes of Arrival)

• Brain MRI with diffusion-weighted imaging is the preferred initial test to detect acute ischemic changes. 2
• CT head without contrast if MRI is unavailable to rule out hemorrhage—this fundamentally changes treatment. 2
• Vascular imaging with CTA or MRA from aortic arch to vertex must be performed without delay to evaluate carotid and vertebral artery disease. 1, 2
• ECG should be performed immediately upon arrival. 1

Critical Vascular Assessment

Immediately assess the radial pulse on the right arm and measure blood pressure in both arms to check for significant arterial compromise. 2 If pulse is absent or blood pressure unmeasurable on the right side, this represents acute arterial occlusion requiring immediate vascular surgery consultation. 2

Differential Diagnosis Considerations

Stroke Syndromes

The combination of unilateral sensory loss and visual disturbances suggests either:

• Posterior circulation stroke affecting the thalamus (sensory loss) and occipital cortex (visual disturbances) 1, 2
• Multiple embolic events affecting different vascular territories 2

Vertebrobasilar Insufficiency

This can present with dizziness, vertigo, diplopia, perioral numbness, blurred vision, tinnitus, ataxia, and bilateral sensory deficits. 3 However, the unilateral nature of the forearm numbness makes this less likely than a focal stroke.

Demyelinating Disease

Multiple sclerosis can present with optic neuritis (blurred vision), paresthesias, and numbness in early stages. 4 However, the acute simultaneous onset makes stroke more likely and more immediately life-threatening.

Guillain-Barré Syndrome

GBS can present with blurred vision, diplopia, extremity numbness and weakness, though bilateral visual deterioration and ascending paralysis are more typical. 5 The unilateral forearm involvement makes this diagnosis less likely.

Critical Time-Dependent Decisions

Do not discharge patients with crescendo or fluctuating symptoms under any circumstances. 1 This patient meets the highest risk criteria for acute stroke due to:

• Unilateral neurological deficit 1
• Acute and potentially fluctuating symptoms 1
• Combination of sensory and visual symptoms suggesting multiple vascular territories 2

Treatment Initiation

If imaging confirms ischemic stroke without hemorrhage, dual antiplatelet therapy (aspirin + clopidogrel 75 mg) should be initiated for the first 21 days in patients with symptomatic carotid stenosis not undergoing revascularization, followed by long-term single antiplatelet therapy. 2

Carotid ultrasound should be performed to identify extracranial carotid stenosis >70% requiring carotid endarterectomy. 2

Common Pitfalls to Avoid

• Do not rely solely on ABCD2 scores for disposition decisions—clinical judgment and imaging findings are paramount. 1
• Do not delay carotid imaging in patients with anterior circulation symptoms. 1
• Do not attribute symptoms to benign causes like cervical arthritis without first ruling out stroke—cervicogenic dizziness is a diagnosis of exclusion and imaging is not indicated unless red flags like neurologic deficits are present. 3
• Do not wait for symptom progression—outcome depends entirely on time to reperfusion in acute arterial occlusion. 2