What is the cause of paresthesia in bilateral legs?

From the Guidelines

Paresthesia in bilateral legs is most commonly caused by peripheral neuropathy, often due to diabetes, and should be promptly evaluated to prevent worsening of symptoms and potential long-term damage. The causes of paresthesia in bilateral legs can be multifactorial, including:

• Peripheral neuropathy (often due to diabetes, vitamin B12 deficiency, or alcohol abuse) 1
• Spinal stenosis, herniated discs, multiple sclerosis, or circulation problems
• Nerve compression syndromes like sciatica
• Medication side effects, particularly from chemotherapy drugs, certain antibiotics, or antiseizure medications

A thorough medical evaluation is essential for proper diagnosis, including:

• Physical examination
• Blood tests to check for diabetes or vitamin deficiencies
• Possibly imaging studies like MRI of the spine

Treatment depends on the underlying cause and may include:

• Addressing nutritional deficiencies
• Managing diabetes
• Physical therapy
• Anti-inflammatory medications
• In some cases, surgical intervention for structural problems

It is crucial to seek medical attention promptly, especially if symptoms are accompanied by weakness, loss of bladder or bowel control, or if symptoms are worsening, as these could indicate a serious condition requiring immediate treatment 1.

From the Research

Causes of Paresthesia in Bilateral Legs

Paresthesia in bilateral legs can be caused by various factors, including:

• Vitamin B12 deficiency, which can lead to peripheral neuropathy 2, 3, 4, 5, 6
• Nutritional deficiencies, such as thiamine, copper, and vitamin B12, which can occur after bariatric surgery 6
• Toxins and medications that can damage peripheral nerves 5
• Other systemic symptoms that can provide etiologic clues 5

Vitamin B12 Deficiency and Paresthesia

Vitamin B12 deficiency is a common cause of peripheral neuropathy, which can manifest as paresthesia in bilateral legs 2, 3, 4. Studies have shown that:

• Low serum B12 levels are associated with peripheral neuropathy 2, 4
• B12 deficiency can cause sensorimotor axonal polyneuropathy and sensory neuronopathy 2
• B12 treatment can improve symptoms of peripheral neuropathy, although the evidence is not yet conclusive 4

Diagnosis and Treatment

Diagnosing the cause of paresthesia in bilateral legs is crucial for effective treatment. Doctors may:

• Conduct electrophysiological studies, such as nerve conduction studies, to confirm neuropathy 2
• Check serum B12 levels and other vitamin and mineral levels to identify deficiencies 2, 4, 6
• Prescribe vitamin supplements, such as B12, to treat deficiencies and improve symptoms 2, 3, 4, 6