What is the appropriate workup for a patient presenting with calf numbness?

From the Guidelines

The appropriate workup for a patient presenting with calf numbness should begin with a thorough history and physical examination, followed by diagnostic testing including duplex ultrasound to rule out deep vein thrombosis (DVT), as recommended by the Society of Radiologists in Ultrasound consensus conference 1. The history should focus on onset, duration, and progression of symptoms, associated sensory or motor deficits, and risk factors for peripheral neuropathy or vascular disease.

• Key points to consider in the history include:
  • Onset and duration of symptoms
  • Associated sensory or motor deficits
  • Risk factors for peripheral neuropathy or vascular disease Physical examination should include a detailed neurological assessment testing sensation, strength, reflexes, and proprioception, along with vascular examination checking pulses and capillary refill.
• The physical examination should evaluate:
  • Sensation
  • Strength
  • Reflexes
  • Proprioception
  • Vascular status Initial diagnostic testing should include basic laboratory studies such as complete blood count, comprehensive metabolic panel, hemoglobin A1c, vitamin B12 level, and thyroid function tests to evaluate for metabolic causes.
• Laboratory tests may include:
  • Complete blood count
  • Comprehensive metabolic panel
  • Hemoglobin A1c
  • Vitamin B12 level
  • Thyroid function tests Electromyography (EMG) and nerve conduction studies are often indicated to assess for peripheral neuropathy or radiculopathy.
• Additional testing may include:
  • Electromyography (EMG)
  • Nerve conduction studies Imaging studies may include lumbar spine MRI if radiculopathy is suspected, particularly if the numbness follows a dermatomal pattern or is associated with back pain.
• Imaging studies may be considered:
  • Lumbar spine MRI Vascular studies such as ankle-brachial index or arterial duplex ultrasound should be considered if peripheral arterial disease is suspected.
• Vascular studies may include:
  • Ankle-brachial index
  • Arterial duplex ultrasound For patients with acute onset of symptoms, especially if accompanied by pain or motor weakness, urgent evaluation is warranted to rule out acute conditions like deep vein thrombosis (using duplex ultrasound) or acute compartment syndrome (measuring compartment pressures if clinically indicated), as suggested by the American College of Radiology 1. The specific workup should be tailored based on the clinical presentation, as calf numbness can result from various etiologies including peripheral neuropathy, lumbar radiculopathy, peripheral vascular disease, or entrapment neuropathies.
• The workup should be individualized based on:
  • Clinical presentation
  • Risk factors
  • Associated symptoms It is essential to consider the potential for DVT, particularly in patients with risk factors, and to use duplex ultrasound as a diagnostic tool, as recommended by the Society of Radiologists in Ultrasound consensus conference 1.

From the Research

Calf Numbness Workup

The appropriate workup for a patient presenting with calf numbness involves a comprehensive evaluation to determine the underlying cause.

• The initial evaluation should include a comprehensive history and physical examination, with a focus on identifying potential underlying etiologies such as diabetes mellitus, nerve compression or injury, alcohol use, toxin exposure, hereditary diseases, and nutritional deficiencies 2.
• Laboratory tests should be selected based on the individual and family history, clinical presentation, and electrophysiological findings 3.
• Basic screening tests for neuropathies should include:
  • A complete blood count (CBC) to evaluate the total numbers and characteristics of cell components in the blood 4, 2, 3
  • A comprehensive metabolic profile to assess renal and liver function, as well as blood glucose levels 5, 2, 3
  • Fasting blood glucose, vitamin B12, and thyroid-stimulating hormone levels to identify potential underlying causes such as diabetes mellitus or thyroid disorders 2, 3
  • Serum protein electrophoresis with immunofixation to evaluate for potential underlying conditions such as multiple myeloma or other plasma cell disorders 2
• If the initial evaluation is inconclusive, referral to a neurologist for additional testing (e.g., electrodiagnostic studies, specific antibody assays, nerve biopsy) should be considered 2, 3.
• Treatment of peripheral neuropathy focuses on managing the underlying etiology, and several classes of medications, including gabapentinoids and antidepressants, can help alleviate neuropathic pain 2.