Differential Diagnosis for Painless Foot Drop
- Single most likely diagnosis
- Peroneal nerve compression or injury: This is a common cause of foot drop, especially if it's painless. The peroneal nerve can be compressed or injured due to various reasons such as crossing legs, wearing tight boots, or direct trauma to the nerve.
- Other Likely diagnoses
- Lumbar radiculopathy (L5 nerve root compression): Compression of the L5 nerve root can cause foot drop, and it may be painless if the compression is mild or intermittent.
- Peripheral neuropathy: Certain types of peripheral neuropathy, such as diabetic neuropathy or Charcot-Marie-Tooth disease, can cause foot drop without significant pain.
- Stroke or cerebral vasculature issues: A stroke or other cerebral vasculature issues can cause foot drop, especially if the motor cortex or corticospinal tract is affected.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Spinal cord compression or cauda equina syndrome: These conditions can cause foot drop, and it's essential to rule them out as they require urgent medical attention to prevent permanent damage.
- Tumor or cyst compressing the peroneal nerve or spinal cord: A tumor or cyst can compress the peroneal nerve or spinal cord, causing foot drop, and it's crucial to diagnose and treat these conditions promptly.
- Rare diagnoses
- Amyotrophic lateral sclerosis (ALS): ALS is a rare neurodegenerative disease that can cause foot drop, among other symptoms.
- Guillain-Barré syndrome: This is a rare autoimmune disorder that can cause foot drop, among other symptoms, due to nerve inflammation.
- Hereditary neuropathies: Certain hereditary neuropathies, such as hereditary neuropathy with liability to pressure palsies, can cause foot drop.