What is the cause of intermittent paresthesias (abnormal sensations) of the left upper extremity (LUE) after coughing spells?

Cough-Induced Transient Neurovascular Compression (Cough Syncope Variant)

The intermittent paresthesias of your left upper extremity after coughing spells are most likely caused by transient neurovascular compression or hemodynamic compromise triggered by the marked elevation in intrathoracic pressure during coughing, representing a variant of cough syncope syndrome. 1, 2

Pathophysiologic Mechanism

The violent expulsive efforts of coughing generate extremely high intrathoracic pressures that can produce several critical effects 1:

• Diminished cardiac output causing decreased systemic blood pressure and consequent cerebral/peripheral hypoperfusion 1
• Increased cerebrospinal fluid pressure causing increased extravascular pressure around cranial vessels and peripheral nerve compression 1
• Transient vascular compromise in patients with underlying cerebrovascular disease or incomplete collateralization 2

A documented case demonstrated that cough-induced hemispheric transient ischemic attacks with arm weakness can occur when there is occlusion of major vessels with inadequate collateral circulation, successfully treated with revascularization 2.

Critical Diagnostic Evaluation Required

You must undergo urgent neurovascular imaging to exclude life-threatening causes:

Immediate Imaging Studies

• CT angiography of head and neck to evaluate for carotid stenosis, occlusion, or vertebrobasilar insufficiency 2
• MRI brain with diffusion-weighted imaging to assess for acute ischemic changes or structural lesions 3
• Assessment of circle of Willis completeness as incomplete collateralization predisposes to hemodynamic symptoms 2

Peripheral Nerve Assessment

• Thoracic outlet syndrome evaluation including positional maneuvers, as cough-induced pressure changes can transiently compress the brachial plexus 3
• Cervical spine imaging if there is history of cervical pathology that could be exacerbated by cough-induced pressure transmission 4

Red Flags Requiring Emergency Evaluation

Seek immediate medical attention if you experience: 3, 5

• Facial weakness accompanying the arm paresthesias
• Visual changes or diplopia
• Severe headache with the episodes
• Progressive or persistent weakness between coughing episodes
• Rapidly ascending symptoms involving both arms or legs

These features may indicate Guillain-Barré syndrome, stroke, or other central nervous system pathology requiring urgent intervention 3, 5.

Management Algorithm

Step 1: Rule Out Vascular Causes

• Complete neurovascular imaging as outlined above 2
• If significant carotid or vertebrobasilar disease identified, vascular surgery consultation for revascularization is indicated 2

Step 2: Treat Underlying Cough

Elimination of cough will eliminate the resultant neurovascular episodes 1. Pursue systematic evaluation per ACCP guidelines 4:

• Chest radiograph to identify structural abnormalities 4
• CT chest and bronchoscopy if cough persists after initial evaluation 4
• Evaluate for common causes: asthma, gastroesophageal reflux, upper airway cough syndrome, medication-induced (ACE inhibitors) 4
• Consider uncommon causes including pulmonary embolism, congestive heart failure, or cervical spine pathology 4

Step 3: Peripheral Nerve Considerations

If vascular imaging is normal, evaluate for 3, 6:

• Thoracic outlet syndrome with provocative maneuvers
• Cervical radiculopathy with MRI cervical spine if positional component exists
• Metabolic causes including diabetes screening, vitamin B12 level, thyroid function 3

Common Pitfalls to Avoid

• Do not dismiss these symptoms as benign without excluding cerebrovascular disease, particularly in middle-aged or older patients with vascular risk factors 1, 2
• Do not attribute symptoms solely to peripheral nerve compression without first ruling out central causes, as the unilateral upper extremity distribution with cough trigger suggests hemodynamic compromise 2
• Do not delay imaging if symptoms are recurrent or progressive, as this may represent critical cerebrovascular insufficiency requiring surgical intervention 2

The typical profile for cough-induced neurovascular symptoms is a middle-aged, large-framed individual with obstructive airways disease who generates extremely high intrathoracic pressures 1. However, the unilateral upper extremity distribution specifically raises concern for hemispheric vascular compromise rather than generalized syncope 2.