The Bottom Line: Differential Diagnosis of foot drop
- Upper motor neuron involvement – CVA can cause weakness of the whole extremity. Due to spasticity, the limb is artificially long. To ambulate, the person rotates the leg in a semicircular fashion, also referred to as circumduction. Dysphagia, aphasia, or upper limb weakness are also evident.
- Cerebellar gait – The cerebellum is responsible for the smoothness and balance of gait. Cerebellar gait deficits are seen as ataxia and failure to walk in tandem.
- Ataxic gait – Presentation is bilateral. Due to the involvement of long tracks of the spinal cord, position and vibration senses are lost. This leads to high steppage and side to side sway, as can be seen in alcohol use disorder.
- Severe L5 lumbar radiculopathy
- Parkinsonian gait – Involvement of substantia nigra causes failure of the smooth transition of the gait cycle leading to initiation problems coupled with short and fast steps called festinate gait.
- Lumbar plexus involvement such as autoimmune, compressive-tumor,
- Diabetic amyotrophy
- Conversion reaction, somatization disorder, and malingering should be considered if the workup is unremarkable, and there is potential for substantial secondary gain, depression, anxiety, or other suspected psychological issues. (Nori)
The Bottom Line 