What is the next step for a patient presenting with foot drop?

Management of Foot Drop

The next step for a patient presenting with foot drop should be a comprehensive neurological assessment to identify the underlying cause, including nerve conduction studies and electromyography to localize the site and determine the severity of the lesion. 1, 2

Initial Evaluation

History

• Duration and onset of symptoms (acute vs. gradual)
• Associated symptoms (pain, numbness, tingling)
• History of trauma, surgery, or recent illness
• Comorbidities (diabetes, stroke, peripheral vascular disease)
• Medication use
• Recent activities (leg crossing, prolonged squatting)

Physical Examination

• Neurological assessment:
  • Motor strength testing (ankle dorsiflexion, toe extension, foot eversion)
  • Sensory testing (light touch, pinprick, vibration)
  • Deep tendon reflexes
• Vascular assessment:
  • Palpation of pedal pulses
  • Assessment for signs of ischemia
• Musculoskeletal assessment:
  • Foot deformities
  • Range of motion

Diagnostic Testing

• Nerve conduction studies and electromyography - Essential for:

  • Localizing the site of lesion (common peroneal nerve, L5 radiculopathy, sciatic nerve)
  • Determining severity of nerve damage
  • Predicting recovery potential 2

• Imaging studies based on suspected etiology:

  • MRI of the spine for suspected radiculopathy
  • MRI or ultrasound of the knee/fibular head for suspected peroneal neuropathy
  • CT or MRI of the brain if central cause is suspected 3

Common Etiologies to Consider

• Peripheral nerve injury (most common: peroneal nerve compression at fibular head)
• L5 radiculopathy
• Sciatic nerve injury
• Lumbar plexopathy
• Central nervous system disorders (stroke, multiple sclerosis, brain tumors)
• Systemic conditions (diabetes, vasculitis)

Immediate Management

1. Ankle-foot orthosis (AFO) - Provide immediate functional improvement and prevent falls 1, 4
2. Physical therapy - Range of motion exercises and strengthening of tibialis anterior and peroneal muscles 1
3. Treatment of underlying cause if identified (e.g., discontinuation of leg crossing if habitual, glycemic control if diabetic)

Pitfalls and Caveats

• Don't assume peroneal nerve compression is the only cause - central causes like brain metastases can present with isolated foot drop 3
• Avoid focusing only on the foot - examine the entire limb and spine
• Don't delay orthotic management while awaiting definitive diagnosis - early intervention with AFO prevents falls and improves mobility 1, 2
• Consider less common causes in patients without obvious risk factors
• Avoid prolonged immobilization which can lead to muscle atrophy and contractures

Follow-up Care

• Regular reassessment of neurological function
• Adjustment of orthotic devices as needed
• Consideration of surgical options (nerve decompression, tendon transfers) for cases without improvement 4, 5
• Fall prevention strategies including home environment assessment 1

By following this structured approach to evaluating and managing foot drop, you can improve patient outcomes by addressing the underlying cause while providing functional support to prevent complications.