From the Guidelines
Bilateral foot drop is primarily caused by damage to the peroneal nerves or their pathways, resulting in weakness or paralysis of the muscles that lift the feet, with diabetic neuropathy being a significant cause, as highlighted in the most recent study 1. The causes of bilateral foot drop can be diverse, including peripheral neuropathies like Guillain-Barré syndrome, Charcot-Marie-Tooth disease, and diabetic neuropathy, which affect nerves bilaterally.
- Central nervous system disorders such as multiple sclerosis, amyotrophic lateral sclerosis (ALS), and spinal cord injuries can also lead to bilateral foot drop by damaging upper motor neurons.
- Compression of nerves from prolonged squatting, crossing legs, or tight casts can cause bilateral symptoms if both sides are affected.
- Systemic conditions including vitamin B12 deficiency, hypothyroidism, and certain medications (particularly chemotherapy drugs like vincristine) may result in peripheral neuropathy affecting both feet.
- Inflammatory conditions like vasculitis can damage multiple nerves simultaneously. According to the most recent guidelines 1, diabetic neuropathy is a diagnosis of exclusion, and up to 50% of diabetic peripheral neuropathy may be asymptomatic, emphasizing the importance of early recognition and management. Treatment depends on identifying and addressing the underlying cause, which may involve medication adjustments, physical therapy, bracing, or in some cases, surgical decompression, as suggested by previous studies 1. Prompt evaluation is essential as bilateral foot drop often indicates a significant neurological condition requiring comprehensive assessment, and the most recent study 1 highlights the importance of early recognition and appropriate management of neuropathy in people with diabetes.
From the Research
Causes of Bilateral Foot Drop (Peroneal Neuropathy)
The causes of bilateral foot drop, also known as peroneal neuropathy, can be attributed to various factors. Some of the possible causes include:
- Metabolic etiologies, such as diabetic ketoacidosis, which can lead to acute-onset peripheral neuropathy 2
- Neurologic etiologies, such as spinal cord compression, degenerative spine disease, or central nervous system lesions 3, 4, 5, 6
- Musculoskeletal etiologies, such as lumbar degenerative disc herniation or peroneal nerve dysfunction 3, 5
- Trauma, such as blunt head trauma or falls, which can cause cerebral contusions, epidural-subdural hematoma, or spinal cord injury 5, 6
- Infections, such as infectious spondylitis, which can compress the conus medullaris and cause bilateral foot drop 6
Specific Causes
Some specific causes of bilateral foot drop include:
- Spinal cord compression at the T12-L1 level, resulting in L5 nerve root compression 3
- Degenerative spinal disease, such as discopathy at the L2/3 to L5/S1 level 4
- Cauda equina syndrome, which can occur with or without acute bilateral foot drop 4
- Upper motor neuron pathologies, such as cerebral contusions or epidural-subdural hematoma, which can cause spastic foot drop 5
- Thoracolumbar lesions, such as T12 infectious spondylitis, which can cause atypical neurological symptoms, including bilateral foot drop 6