Differential Diagnosis for Foot Drop
The patient's inability to bend their left foot up and down, also known as foot drop, can be caused by various conditions. Here's a differential diagnosis organized into categories:
- Single Most Likely Diagnosis
- Peroneal Nerve Palsy: This is the most common cause of foot drop. The peroneal nerve controls the muscles responsible for ankle dorsiflexion (lifting the foot up). Damage to this nerve can result from trauma, compression, or nerve entrapment.
- Other Likely Diagnoses
- L5 Radiculopathy: Compression or damage to the L5 nerve root can cause foot drop, as this nerve root supplies the peroneal muscles.
- Stroke or Cerebral Vasculature Accidents: A stroke can cause weakness or paralysis of the muscles controlling foot movement, leading to foot drop.
- Muscular Dystrophy: Certain types of muscular dystrophy, such as Charcot-Marie-Tooth disease, can cause progressive muscle weakness, including foot drop.
- Do Not Miss Diagnoses
- Cauda Equina Syndrome: A serious condition caused by compression of the spinal nerves in the lower back, which can lead to foot drop, as well as bladder and bowel dysfunction.
- Spinal Cord Compression: Compression of the spinal cord can cause foot drop, among other symptoms, and requires urgent medical attention.
- Tumor or Cyst: A tumor or cyst compressing the peroneal nerve or spinal cord can cause foot drop.
- Rare Diagnoses
- Amyotrophic Lateral Sclerosis (ALS): A progressive neurological disease that can cause muscle weakness, including foot drop.
- Polio: Although rare in developed countries, polio can cause foot drop, especially if the patient has a history of travel to endemic areas.
- Diabetic Amyotrophy: A rare complication of diabetes that can cause muscle weakness, including foot drop.
Management and Treatment
The management and treatment of foot drop depend on the underlying cause. In general, treatment may include:
- Physical therapy to strengthen the affected muscles
- Orthotics or ankle-foot orthoses to support the foot and ankle
- Medications to manage pain, inflammation, or underlying conditions
- Surgery to repair or decompress damaged nerves or to stabilize the foot and ankle
Referral
Patients with foot drop should be referred to:
- Orthopedic Surgeon: For evaluation and treatment of musculoskeletal causes of foot drop.
- Neurologist: For evaluation and treatment of neurological causes of foot drop, such as stroke, muscular dystrophy, or peripheral neuropathy.
- Physical Medicine and Rehabilitation (PM&R) Physician: For rehabilitation and management of foot drop, including physical therapy and orthotics.
- Podiatrist: For evaluation and treatment of foot and ankle conditions that may be contributing to foot drop.