What is the initial workup for a patient presenting with gait instability?

Initial Workup for Gait Instability

The initial workup for gait instability should include a comprehensive mobility assessment with standardized tests such as the Timed Up and Go (TUG) test, focused neurological examination, vascular assessment including ankle-brachial index (ABI), and targeted laboratory studies to identify treatable causes.

Clinical Assessment

History

• Fall history: Ask three key screening questions 1:
  • Have you fallen in the past year?
  • Do you feel unsteady when standing or walking?
  • Are you worried about falling?
• Symptom characterization:
  • Onset (sudden vs. gradual)
  • Duration and progression
  • Aggravating/alleviating factors
  • Associated symptoms (vertigo, pain, weakness)
• Medical history focusing on:
  • Neurological conditions
  • Cardiovascular disease
  • Diabetes and peripheral neuropathy
  • Visual impairment
  • Orthopedic conditions

Physical Examination

Mobility Assessment

• Observe gait pattern from when patient enters room
• Perform standardized mobility tests:
  • Timed Up and Go (TUG) test: Patient rises from chair, walks 3 meters, turns, returns to chair, and sits down (>12 seconds indicates increased fall risk) 1
  • 4-Stage Balance Test: Assess ability to maintain four increasingly challenging positions for 10 seconds each (inability to hold tandem stance for 10 seconds indicates increased fall risk) 1

Neurological Examination

• Assess for loss of protective sensation:
  • 10-g monofilament test (primary test)
  • At least one additional test: pinprick, temperature sensation, vibration using 128-Hz tuning fork, or ankle reflexes 1
• Evaluate strength, coordination, and proprioception
• Check for signs of parkinsonism or cerebellar dysfunction
• Assess cognitive status if indicated

Vascular Assessment

• Inspect lower extremities for skin changes
• Palpate pedal pulses
• Ankle-brachial index (ABI) testing if signs/symptoms of peripheral arterial disease (PAD) 1
  • ABI ≤0.90 confirms PAD diagnosis
  • Consider post-exercise ABI if resting ABI >0.90 but clinical suspicion remains
  • In diabetic patients, consider toe pressure (TP) or toe-brachial index (TBI) measurements 1

Laboratory and Imaging Studies

Initial Laboratory Tests

• Complete blood count
• Comprehensive metabolic panel including:
  • Electrolytes (including calcium and magnesium)
  • Blood urea nitrogen and creatinine
  • Liver function tests
  • Fasting blood glucose/HbA1c
• Thyroid-stimulating hormone
• Vitamin B12 and folate levels
• Vitamin D level

Imaging

• Consider brain imaging (CT or MRI) if:
  • Sudden onset of symptoms
  • Focal neurological findings
  • Signs of increased intracranial pressure
  • History suggesting cerebrovascular event
• Consider spine imaging if:
  • Radicular symptoms
  • Myelopathic features
  • History of trauma

Special Considerations

Elderly Patients

• Assess for frailty using standardized tools
• Evaluate for polypharmacy and medication side effects using the P-SCHEME framework 1:
  • Pain (axial or lower extremity)
  • Shoes (suboptimal footwear)
  • Cognitive impairment
  • Hypotension (orthostatic or iatrogenic)
  • Eyesight (vision impairment)
  • Medications (centrally acting)
  • Environmental factors

Diabetic Patients

• More thorough vascular and neurological assessment
• Evaluate for diabetic neuropathy and foot ulcers
• Consider specialized footwear needs 1

Red Flags Requiring Urgent Evaluation

• Sudden onset of gait instability
• Associated focal neurological deficits
• Signs of brainstem or cerebellar dysfunction
• Critical limb ischemia (ankle pressure <50 mmHg, toe pressure <30 mmHg, or TcPO2 <25 mmHg) 1

Management Considerations

Based on the initial workup, patients may require:

• Physical therapy referral for gait training and balance exercises
• Assistive devices (cane, walker)
• Medication adjustments
• Vascular intervention for severe PAD
• Specialized footwear for those with foot deformities or neuropathy

Common Pitfalls to Avoid

1. Attributing gait instability solely to age without thorough evaluation
2. Missing peripheral arterial disease as a contributing factor
3. Overlooking medication side effects as a cause
4. Failing to assess fall risk in patients with gait instability
5. Not considering multiple contributing factors (most gait disorders have multiple causes)

By following this structured approach to evaluating gait instability, clinicians can identify underlying causes, implement appropriate interventions, and potentially prevent serious complications such as falls and associated injuries.