Features

Foot drop is characterized by steppage gait. When the person with foot drop walks, the foot slaps down onto the floor. To compensate for the toe drop, the patient must raise the thigh excessively, as if walking upstairs.

Patients with painful disorders of sensation (dysesthesia) of the soles of the feet may have a similar gait, but do not have foot drop. Because of the extreme pain evoked by even the slightest pressure on the feet, the patient walks as if walking barefoot on hot sand.

Pathophysiology

• Conditions affecting the nervous system
  • Amyotrophic lateral sclerosis (Lou Gehrig's disease)
  • Lumbar radiculopathy (L4 and L5 nerve roots)
  • Spinal disc herniation
  • Multiple Sclerosis
  • Peripheral neuropathies: Multifocal motor neuropathy (foot drop may be the presenting symptom), diabetic neuropathy
  • Common peroneal nerve palsy
  • Charcot-Marie-Tooth disease (peroneal muscular atrophy)
  • Progressive spinal muscular atrophy
  • Poliomyelitis
  • Leprosy
  • Compartment syndrome
  • Human monocytic ehrlichiosis (long term manifestation)
  • Cryoglobulinemia
• Conditions affecting the musculature
  • Different kinds of muscular dystrophy (Duchenne muscular dystrophy, Facioscapulohumeral dystrophy, scapuloperoneal muscular dystrophy, Myotonic dystrophy, desmin myopathy,
  • Inclusion body myositis
• Drugs
  • Vincristine (adults more severely affected than children) (Adams and Victor)
  • Auranofin
  • Allopurinol (causal relationship not established)
  • Glatiramer (uncommon)
  • Chymopapain (uncommon)
  • Thalidomide (uncommon)
• Toxins
  • Lead neuropathy (usually presents with wrist and finger drop, foot drop less common) (Adams and Victor)

Treatment

The underlying disorder must be treated. Ankles can be stabilized by lightweight orthoses, and shoes can be fit with springs to prevent foot drop while walking. Regular exercise is usually prescribed.

The latest treatments include stimulation of the peroneal nerve that lifts the foot when you step. Many stroke and multiple sclerosis patients with foot drop have had success with it.

Called a "WalkAide", it is a small device worn around the top of the calf. It senses the angle of the leg during a walk step and stimulates the nerve to lift the foot at the appropriate time. The effect is a near-normal return of mobility. With consistent use a person will get stronger and able to walk further and faster. Website is http://www.walkaide.us