What is the appropriate workup and management for a 71-year-old female with intermittent numbness and tingling in her left hand and bilateral feet?

Diagnostic Workup for Intermittent Numbness and Tingling in an Elderly Patient

A comprehensive neurological evaluation is essential for this 71-year-old female with intermittent numbness and tingling affecting her left hand and bilateral feet, as these symptoms suggest peripheral neuropathy requiring thorough investigation to identify the underlying cause and prevent progression.

Initial Assessment

Key History Elements to Obtain:

• Exact pattern and distribution of symptoms (stocking-glove vs asymmetric)
• Timing and duration of each episode
• Aggravating or alleviating factors
• Associated symptoms (pain, weakness, burning sensations)
• Medical history, focusing on:
  • Diabetes
  • Previous cancer treatment (especially chemotherapy)
  • Vitamin deficiencies
  • Thyroid disease
  • Alcohol consumption
  • Medication history (particularly neurotoxic medications)

Physical Examination:

• Complete neurological examination focusing on:
  • Sensory testing (light touch, pinprick, vibration, proprioception)
  • Motor strength assessment
  • Deep tendon reflexes
  • Coordination testing
  • Assessment for autonomic symptoms

Diagnostic Testing

First-Line Laboratory Tests:

• Complete blood count
• Comprehensive metabolic panel
• Fasting blood glucose and HbA1c
• Vitamin B12 level
• Thyroid-stimulating hormone (TSH)
• Serum protein electrophoresis with immunofixation 1

Additional Testing Based on Clinical Suspicion:

• Nerve conduction studies/electromyography (EMG) if symptoms persist or worsen
• MRI of cervical spine if radiculopathy is suspected
• Ultrasound of wrists if carpal tunnel syndrome is suspected 2

Differential Diagnosis

Common Causes to Consider:

1. Peripheral Neuropathy:

   • Diabetic neuropathy
   • Vitamin B12 deficiency
   • Medication-induced neuropathy
   • Idiopathic neuropathy (25-46% of cases) 1

2. Compression Neuropathies:

   • Carpal tunnel syndrome (median nerve)
   • Cubital tunnel syndrome (ulnar nerve)
   • Cervical radiculopathy 3

3. Systemic Conditions:

   • Thyroid dysfunction
   • Monoclonal gammopathy
   • Vasculitis 2

Management Approach

If Peripheral Neuropathy is Confirmed:

• Treat underlying cause if identified
• For neuropathic pain:
  • Duloxetine (first-line) - start at 30 mg/day for one week, then increase to 60 mg/day 4, 5
  • Alternative options: gabapentin, pregabalin, or tricyclic antidepressants 4

If Chemotherapy-Induced Peripheral Neuropathy (CIPN) is Suspected:

• Duloxetine is the only agent with moderate evidence supporting its use for CIPN 4
• Exercise therapy may provide benefit but has limited evidence 4
• Acupuncture may be considered but has insufficient evidence for a formal recommendation 4

For Compression Neuropathies:

• Wrist splinting for carpal tunnel syndrome
• Activity modification
• Consider referral to specialist if symptoms persist 3, 2

Follow-up and Monitoring

• Schedule follow-up in 4-6 weeks to assess symptom progression and response to treatment
• Monitor for development of:
  • Motor weakness
  • Autonomic symptoms
  • Proximal progression of symptoms
  • Functional impairment

Red Flags Requiring Urgent Referral

• Rapid progression of symptoms
• Motor weakness
• Asymmetric pattern with severe symptoms
• Associated autonomic dysfunction
• Symptoms that significantly impact activities of daily living 5, 2

Patient Education

• Importance of reporting changes in symptoms
• Protective measures for areas with decreased sensation
• Medication adherence and potential side effects
• Lifestyle modifications (regular exercise, balanced diet)

Remember that early identification of the underlying cause is critical, as continued exposure to certain causative factors may lead to irreversible neurological damage 5.