Can numbness on one side of the body, specifically the left arm, forearm, and hand, be a symptom of a Transient Ischemic Attack (TIA)?

Can Isolated Left Arm Numbness Be a TIA?

Yes, isolated numbness of the left arm, forearm, and hand can absolutely be considered a TIA and represents a high-risk symptom requiring emergency evaluation. This is a recognized focal neurological deficit consistent with ischemia in the distribution of the right internal carotid or middle cerebral artery territory 1.

Why This Is a TIA Symptom

Unilateral sensory symptoms, including hemibody sensory loss or paresthesia affecting one side, are explicitly recognized as classic TIA presentations 1, 2. The guidelines specifically state that ischemia in the distribution of the right internal carotid artery or middle cerebral artery causes "left-sided paresthesia or sensory loss" 1.

• Left arm numbness represents contralateral sensory deficit from right hemisphere ischemia 1
• Sensory symptoms alone (without motor weakness) still constitute high-risk TIA presentations 2, 3
• The symptom pattern fits the anterior circulation territory distribution 1

Urgency of Evaluation

Patients with isolated numbness presenting within 48 hours are at HIGH RISK for completed stroke and require same-day emergency assessment 3.

• The 90-day stroke risk after TIA is approximately 10%, with half occurring within the first 2 days 4
• Recent data shows 1.5% stroke risk at 2 days and 2.1% at 7 days even with rapid intervention 2
• The highest stroke risk occurs in the first 48 hours 3

Critical Immediate Actions

Send the patient immediately to an emergency department for stroke evaluation 3, 4:

• Check radial pulse and blood pressure in both arms to rule out acute arterial occlusion 3
• If pulse absent or BP unmeasurable on left side, this is acute arterial occlusion requiring immediate vascular surgery 3
• Brain imaging (MRI with diffusion-weighted imaging preferred, or CT if unavailable) must be performed immediately 3
• Vascular imaging (CTA or MRA from aortic arch to vertex) to evaluate for carotid stenosis 3
• Carotid duplex ultrasonography to detect stenosis requiring intervention 1

Common Pitfall to Avoid

Do not dismiss isolated sensory symptoms as "purely sensory" and therefore less concerning 1. While the 2011 guidelines mention that purely sensory symptoms should prompt consideration of radiculopathy or neuropathy 1, the more recent 2025 consensus explicitly recognizes that "isolated numbness alone (hemibody sensory loss) still represents high risk for stroke" 3.

• When symptoms are purely sensory, alternative diagnoses like radiculopathy or neuropathy should be considered 1
• However, the acute onset and unilateral distribution strongly favor TIA over peripheral causes 1
• The combination of left arm numbness with facial weakness or speech disturbance increases stroke probability to 72% 3

Treatment Implications

If carotid stenosis is identified, dual antiplatelet therapy (aspirin + clopidogrel 75 mg) for 21 days is recommended 3:

• Carotid stenosis >70% may require carotid endarterectomy 3
• Long-term single antiplatelet therapy follows the initial dual therapy period 3
• Comprehensive stroke prevention measures must be initiated within 24 hours 3