What is the initial workup for hand paresthesia?

Initial Workup for Hand Paresthesia

Begin with a focused clinical assessment to localize the lesion along the sensory pathway, followed by plain radiographs and nerve conduction studies when peripheral nerve entrapment is suspected, as this represents the most common etiology. 1, 2

Clinical History and Examination

Critical Historical Features to Elicit

• Onset and progression: Acute onset (within days), rapidly progressive, or severe symptoms warrant urgent evaluation for conditions like Guillain-Barré syndrome or vasculitis requiring immediate management 2
• Distribution pattern: Determine if paresthesias are unilateral or bilateral, symmetric or asymmetric, distal or proximal 1, 2
• Associated symptoms: Screen for dizziness, dysphagia, diplopia, hyperacusis, limb weakness, or severe dysautonomia which suggest central or systemic causes 1
• Vascular risk factors: Assess for hypertension, diabetes, smoking history, and family history of stroke 1

Physical Examination Priorities

• Neurological assessment: Document motor strength, sensory deficits, deep tendon reflexes, and proprioception 2, 3
• Distribution mapping: Have patients complete a self-administered hand diagram to classify symptoms as classic, probable, possible, or unlikely carpal tunnel syndrome (sensitivity 80%, specificity 90%) 4
• Provocative maneuvers: Perform Tinel's and Phalen's tests for carpal tunnel syndrome 2

Initial Diagnostic Testing

First-Line Imaging

Radiography of the hand and wrist (posteroanterior, lateral, and oblique views) should be obtained initially to exclude structural abnormalities, fractures, or arthritis. 5, 6

Electrodiagnostic Studies

• Nerve conduction studies and EMG are indicated when peripheral nerve entrapment is suspected based on clinical presentation 1, 2
• The severity of neurophysiological impairment correlates with symptom distribution: patients with severe median nerve damage typically present with paresthesias confined to the median nerve territory, while milder cases often present with "glove" distribution affecting the entire hand 7, 8

Advanced Imaging When Indicated

• Ultrasound is particularly valuable for diagnosing carpal tunnel syndrome by measuring median nerve cross-sectional area and identifying compression, and can reveal space-occupying lesions, anatomical variations, or anomalous muscles 6, 2
• MRI without IV contrast should be obtained for suspected central causes when there is no clear peripheral etiology, to rule out central nervous system lesions 1

Laboratory Evaluation

Laboratory testing is not routinely recommended unless specific systemic conditions are suspected based on history and examination. 1 Consider the following when clinically indicated:

• Diabetes screening: Fasting glucose or HbA1c, as diabetic polyneuropathy is a common cause of symmetric distal paresthesias 2
• Vitamin B12 level: Deficiency can cause polyneuropathy with acroparesthesias 2
• Thyroid function: Hypothyroidism is associated with carpal tunnel syndrome 2
• Serum protein electrophoresis: To screen for monoclonal gammopathy of undetermined significance 2
• Lyme serology: In endemic areas, as Lyme disease can cause neurological symptoms including paresthesias 1

Diagnostic Algorithm Based on Clinical Presentation

Unilateral Hand Paresthesias

• Most commonly represents carpal tunnel syndrome (mononeuropathy) 2
• Obtain hand/wrist radiographs and nerve conduction studies 6, 1
• Consider ultrasound for detailed nerve assessment and to guide potential steroid injection 2

Bilateral Symmetric Distal Paresthesias

• Suggests polyneuropathy, most often due to diabetes 2
• Screen for metabolic causes: glucose, B12, thyroid function 2
• Nerve conduction studies to confirm and characterize polyneuropathy 2

Proximal or Multifocal Paresthesias

• Requires urgent evaluation for vasculitis, Guillain-Barré syndrome, or central causes 2
• Obtain brain and spine MRI with contrast 1
• Consider immediate neurological consultation 1

Common Pitfalls to Avoid

• Do not dismiss proximal pain in carpal tunnel syndrome patients: Proximal upper limb pain occurs frequently and paradoxically correlates with milder median nerve damage and greater hand paresthesias 7
• Recognize that "glove distribution" paresthesias can indicate carpal tunnel syndrome: This pattern reflects milder nerve damage, while symptoms confined to median nerve territory suggest more severe involvement 8
• Do not delay evaluation of rapidly progressive or asymmetric symptoms: These patterns may indicate serious conditions requiring urgent intervention 2

When to Refer

• Immediate neurological consultation for acute onset, rapidly progressive symptoms, or suspected central causes 1
• Neurology referral for persistent symptoms, incomplete recovery, or when diagnosis remains unclear after initial workup 1
• Hand surgery referral for confirmed carpal tunnel syndrome with severe symptoms or failed conservative management 2