What is the diagnosis for a patient with tingling and numbness on the left side of the body and an inability to feel pulse or blood pressure on the left side?

Diagnosis: Acute Arterial Occlusion (Likely Subclavian or Axillary Artery) with Limb Ischemia

This patient most likely has acute arterial occlusion of the left subclavian or axillary artery, presenting with absent left-sided pulse/blood pressure and neurological symptoms from limb ischemia—this is a vascular emergency requiring immediate imaging and intervention to prevent limb loss and permanent neurological damage.

Clinical Reasoning

Key Diagnostic Features

The combination of unilateral absence of pulse and blood pressure with ipsilateral tingling/numbness points directly to acute arterial insufficiency rather than a primary neurological event 1. This presentation differs fundamentally from stroke, which would cause contralateral (right-sided) symptoms if originating from left brain structures 1.

Critical distinguishing factors:

• Ipsilateral symptoms (left-sided neurological symptoms with left-sided vascular compromise) indicate peripheral vascular pathology, not central nervous system disease 1
• Absent pulse and unmeasurable blood pressure on the affected side confirms arterial occlusion—this is pathognomonic for large vessel obstruction 2
• The tingling and numbness represent acute peripheral nerve ischemia from inadequate limb perfusion 3

Differential Diagnosis Priority

Primary consideration: Acute arterial occlusion due to:

• Thromboembolism (cardiac source, atherosclerotic plaque)
• Arterial dissection (subclavian or axillary artery) 4
• Thoracic outlet syndrome with acute thrombosis
• Aortic arch pathology with branch vessel involvement 2

Less likely but consider:

• Subclavian steal syndrome (typically chronic, not acute presentation)
• Fibromuscular dysplasia with acute thrombosis 4

Immediate Management Algorithm

Step 1: Confirm Vascular Emergency (Within Minutes)

• Compare bilateral blood pressures in both arms—>20 mmHg difference confirms significant arterial compromise 2
• Assess the "6 P's" of acute limb ischemia: Pain, Pallor, Pulselessness (confirmed), Paresthesias (confirmed), Poikilothermia (cool limb), Paralysis 2
• Check capillary refill and skin temperature of left hand versus right 2

Step 2: Urgent Vascular Imaging (Within 1 Hour)

CT angiography from aortic arch to fingertips is the gold standard 2:

• Identifies occlusion location and extent
• Differentiates thrombosis from dissection
• Guides endovascular versus surgical intervention 2

Alternative if CTA unavailable: Doppler ultrasound of subclavian/axillary/brachial arteries, but this delays definitive diagnosis 2

Step 3: Concurrent Supportive Measures

• Do NOT elevate the affected limb—keep at heart level or slightly dependent to maximize perfusion 2
• Initiate anticoagulation (heparin bolus followed by infusion) unless contraindicated, to prevent thrombus propagation 2
• Avoid blood pressure cuffs on the affected arm to prevent further compression injury 3
• Supplemental oxygen if oxygen saturation <94% 2

Step 4: Definitive Treatment (Within 4-6 Hours)

Time is critical—irreversible nerve and muscle damage occurs after 6 hours of complete ischemia 2:

• Endovascular thrombectomy/thrombolysis for acute thromboembolism
• Surgical bypass or repair for dissection or anatomical lesions
• Fasciotomy if compartment syndrome develops post-reperfusion 2

Critical Pitfalls to Avoid

Do not mistake this for stroke: The ipsilateral nature of symptoms with absent pulse excludes typical stroke presentation, which causes contralateral deficits 1. Pursuing stroke protocols would dangerously delay vascular intervention.

Do not attribute symptoms to peripheral neuropathy: Acute onset with absent pulse indicates vascular emergency, not chronic nerve disease 5, 3.

Do not delay for "observation": This is a time-sensitive emergency comparable to acute myocardial infarction—every minute of ischemia increases risk of limb loss and permanent disability 2.

Avoid hypertensive treatment: Unless systolic BP >220 mmHg, do not lower blood pressure as this may worsen limb perfusion 2, 6.

Prognosis Determinants

Outcome depends entirely on time to reperfusion 2:

• <6 hours: Excellent limb salvage and functional recovery
• 6-12 hours: Increased risk of compartment syndrome and permanent nerve damage

• 12 hours: High probability of amputation or permanent disability

The combination of motor and sensory symptoms indicates advanced ischemia requiring immediate intervention 2, 3.