What is the differential diagnosis for a right-sided headache with left-sided tingling in the fingers?

Differential Diagnosis for Right-Sided Headache with Left-Sided Finger Tingling

Life-Threatening Causes Requiring Immediate Evaluation

This presentation of right-sided headache with contralateral (left-sided) finger tingling strongly suggests a vascular or structural lesion affecting the right cerebral hemisphere, and stroke/TIA must be excluded emergently. 1

Acute Ischemic Stroke or TIA

• Right-sided internal carotid or middle cerebral artery territory ischemia characteristically produces left-sided paresthesia or sensory loss, along with potential left-sided weakness, left-sided neglect, and abnormal visual-spatial ability 1
• The combination of ipsilateral headache with contralateral neurological symptoms is a classic presentation of acute cerebrovascular events 1
• Symptoms lasting >24 hours indicate stroke, while those <24 hours (typically 15 minutes) suggest TIA, though modern imaging often shows infarction even with brief symptoms 1
• Immediate non-contrast CT head is mandatory to exclude hemorrhage, followed by vascular imaging (CTA or MRA) to identify arterial occlusion or stenosis 1

Cerebral Venous Sinus Thrombosis

• Can present with unilateral throbbing headache and contralateral neurological symptoms 2
• More common in females and requires high clinical suspicion as it mimics more common headache disorders 2
• CT or MR venography is essential for diagnosis, as non-contrast CT may appear normal initially 2
• Immediate anticoagulation prevents fatal complications 2

Intracranial Hemorrhage or Mass Lesion

• Space-occupying lesions in the right hemisphere can cause ipsilateral headache with contralateral sensory symptoms 3
• Non-contrast CT head is the initial imaging modality of choice for acute presentations 1, 3
• MRI with contrast is preferred for subacute presentations when tumor or inflammatory process is suspected 3

Primary Headache Disorders with Neurological Features

Migraine with Aura

• Sensory aura occurs in approximately 31% of migraine with aura patients, typically manifesting as unilateral paresthesia (pins and needles/numbness) that spreads gradually in the face or arm 1
• Aura symptoms should spread gradually over ≥5 minutes, last 5-60 minutes, and be followed by headache within 60 minutes 1
• The headache is typically unilateral, pulsating, moderate-to-severe intensity, and aggravated by routine physical activity 1
• However, the simultaneous presentation of headache with sensory symptoms (rather than sequential) makes this diagnosis less likely and warrants exclusion of secondary causes first 1

Hemiplegic Migraine

• A rare migraine subtype that can include motor symptoms lasting up to 72 hours 1
• Should only be diagnosed after excluding stroke and other structural lesions 1

Other Secondary Causes to Consider

Cervical Spine Pathology with Radiculopathy

• Cervical nerve root compression can cause unilateral arm paresthesia and occipital/suboccipital headache 1
• Pain should be provoked by cervical movement rather than posture alone, with reduced cervical range of motion and myofascial tenderness 1
• Radicular symptoms typically follow dermatomal patterns rather than diffuse finger tingling 1

Spontaneous Intracranial Hypotension

• Can present with severe headache, though typically orthostatic in nature 1
• May be complicated by cerebral venous thrombosis in rare cases 1
• Headache should be absent or mild on waking, worsen within 2 hours of becoming upright, and improve >50% within 2 hours of lying flat 1

Critical Red Flags Present in This Case

The combination of unilateral headache with contralateral sensory symptoms is NOT a feature of benign primary headaches and mandates urgent evaluation for secondary causes 1, 3:

• Focal neurological symptoms (left finger tingling) with headache 4, 5
• Symptoms suggesting hemispheric localization 1
• Pattern inconsistent with typical migraine aura (which should precede rather than accompany headache) 1

Immediate Diagnostic Approach

Emergent evaluation is required 1, 4:

1. Complete neurological examination focusing on:

   • Left-sided motor strength, sensory function, and coordination 1
   • Visual fields (assess for right homonymous hemianopsia) 1
   • Cranial nerve examination 1
   • Neglect and visual-spatial testing 1

2. Immediate non-contrast CT head to exclude hemorrhage or mass effect 1, 3, 4

3. Vascular imaging (CTA or MRA) to evaluate for:

   • Carotid or vertebral artery stenosis or dissection 1
   • Intracranial arterial occlusion 1
   • Venous sinus thrombosis (requires CT or MR venography) 2

4. Carotid duplex ultrasonography as initial vascular screening if patient is stable 1

5. MRI brain with diffusion-weighted imaging if CT is negative but stroke remains suspected 1

Common Pitfalls to Avoid

• Do not attribute contralateral neurological symptoms to migraine without first excluding stroke/TIA 1, 3
• Do not dismiss unilateral sensory symptoms as benign without vascular imaging 1, 2
• Do not rely on symptom duration alone to exclude stroke, as TIA patients may have permanent infarction on imaging despite brief symptoms 1
• Do not miss cerebral venous thrombosis by ordering only non-contrast CT, as dedicated venography is required 2