EpistemisFoot drop
Specialty: Musculoskeletal.
Why it occurs
- Compression of the common peroneal nerve at the head of the fibula (from crossing the legs, splints, or tight casts)
- Severe L4-L5 lumbar radiculopathy due to massive disc herniation
- Asymmetric diabetic neuropathy (mononeuritis multiplex)
- Cerebrovascular accident (CVA) with involvement of the cortical motor area of the lower limb
- Amyotrophic lateral sclerosis (ALS, initial presentation with unilateral foot drop)
- Sequel to knee or hip replacement surgery (iatrogenic sciatic or peroneal injury)
Initial workup
Needle electromyography (EMG) and motor conduction velocities of the common peroneal and posterior tibial nerves, comparing both sides | Magnetic resonance imaging of the lumbar spine to assess L4-L5 root compression | High-resolution ultrasound of the fibular head to rule out masses or compressive intraneural cysts.
red flags
Sudden appearance of bilateral foot drop, inability to walk on heels associated with loss of sensitivity in the perineal region and loss of bladder or anal control (cauda equina syndrome, requires emergency decompressive surgery).
Standard management
- There are no drugs that recover muscle strength of mechanical compressive origin — requires surgical decompression or use of Rancho-type anti-equinus orthosis); in case of associated metabolic or inflammatory polyneuropathy: Methylprednisolone (1 g IV daily for 3 days, if mononeuritis multiplex is suspected in the context of autoimmune vasculitis
- Thioctic or alpha-lipoic acid (600 mg daily orally, adjuvant in diabetic neuropathy).
Educational guidance for study. It is NOT a prescription recommendation. The actual choice depends on the cause, the patient, and current guidelines.
- Area
- Musculoskeletal
- Listed causes
- 6
- Treatment options
- 2