Differential Diagnosis for Lower Extremity Weakness and Paresthesia
Single Most Likely Diagnosis
- Lumbar Radiculopathy: This condition, often due to a herniated disc, is a common cause of lower extremity weakness and paresthesia. The symptoms typically follow a dermatomal pattern, making it a likely diagnosis for patients presenting with these symptoms.
Other Likely Diagnoses
- Peripheral Neuropathy: Conditions such as diabetic neuropathy can cause widespread lower extremity weakness and paresthesia. The symptoms are often bilateral and can be accompanied by other systemic symptoms.
- Lumbosacral Plexopathy: Inflammation or injury to the lumbosacral plexus can cause lower extremity weakness and paresthesia. This condition can be due to various causes, including diabetes, trauma, or infection.
- Spinal Stenosis: Narrowing of the spinal canal can compress the spinal cord or nerve roots, leading to lower extremity weakness and paresthesia, especially with walking or standing.
Do Not Miss Diagnoses
- Cauda Equina Syndrome: A serious condition caused by compression of the cauda equina, which can result in severe and permanent neurological damage if not promptly treated. Symptoms include severe lower back pain, bilateral sciatica, and bowel or bladder dysfunction.
- Spinal Cord Infarction: A rare but potentially devastating condition that can cause sudden onset of lower extremity weakness and paresthesia. It requires immediate medical attention.
- Guillain-Barré Syndrome: An autoimmune disorder that can cause rapid onset of lower extremity weakness, which can ascend to involve the upper limbs and potentially lead to respiratory failure.
Rare Diagnoses
- Vasculitis (e.g., Giant Cell Arteritis, Polyarteritis Nodosa): Inflammation of blood vessels can cause ischemia to nerves, leading to weakness and paresthesia. These conditions are rare but can be serious.
- Neurosyphilis: A complication of untreated syphilis infection, which can cause a variety of neurological symptoms, including lower extremity weakness and paresthesia.
- Tumor (e.g., Neurofibroma, Schwannoma): Benign or malignant tumors can compress nerves, causing lower extremity weakness and paresthesia. These are less common causes but should be considered in the differential diagnosis.