What are the causes of frequent leg paresthesia (abnormal sensations)?

From the Guidelines

Frequent leg paresthesia is most commonly caused by peripheral neuropathy, often associated with diabetes, as well as nerve compression, vitamin B12 deficiency, and circulatory issues, and a thorough medical evaluation is necessary to determine the underlying cause and appropriate treatment. The causes of frequent leg paresthesia can be diverse, including:

• Nerve compression from prolonged sitting or crossing legs
• Peripheral neuropathy, which is often associated with diabetes 1
• Vitamin B12 deficiency
• Circulatory issues, such as peripheral artery disease (PAD) 1
• Systemic conditions like multiple sclerosis

According to the most recent guidelines, patients with diabetes should be screened annually for diabetic peripheral neuropathy (DPN) symptoms using simple clinical tests, such as assessment of pinprick sensation, vibration threshold, and light touch perception using a 10-g monofilament 1. If you experience persistent or worsening symptoms, it's essential to consult a healthcare provider for proper diagnosis and treatment. They may recommend blood tests to check for vitamin deficiencies or diabetes, or neurological exams to assess nerve function. In many cases, simple lifestyle changes like improving posture, taking regular breaks from sitting, and ensuring proper nutrition can help alleviate symptoms. However, underlying medical conditions may require specific treatments, such as medication for diabetes management or vitamin B12 supplements for deficiency. Understanding the cause is crucial for effective management of leg paresthesia.

The diagnosis of DPN should follow the typical pattern, starting distally and moving proximally until threshold is detected 1. Electrophysiological testing or referral to a neurologist is rarely needed, except in situations where the clinical features are atypical or the diagnosis is unclear. In patients with severe or atypical neuropathy, causes other than diabetes should always be considered, such as neurotoxic medications, heavy metal poisoning, alcohol abuse, vitamin B12 deficiency, renal disease, chronic inflammatory demyelinating neuropathy, inherited neuropathies, and vasculitis 1.

In addition to diabetes management, treatment options for DPN may include pregabalin, duloxetine, and tapentadol, as well as tricyclic antidepressants, gabapentin, venlafaxine, carbamazepine, topical capsaicin, and tramadol 1. Foot care is also essential, particularly for patients with a history of foot ulceration or amputation, foot deformities, peripheral neuropathy, PAD, poor glycemic control, visual impairment, and cigarette smoking 1.

Overall, a comprehensive medical evaluation and proper diagnosis are necessary to determine the underlying cause of frequent leg paresthesia and to develop an effective treatment plan.

From the FDA Drug Label

Paresthesia 2.2 0.6

Nervous system disorders Somnolence 35.7 11.5 Dizziness 20.9 6.9 Disturbance in attention 3.8 0 Memory impairment 3.3 1.1 Paresthesia 2.2 0.6

The causes of frequent leg paresthesia (abnormal sensations) are not directly stated in the drug label. However, Paresthesia is listed as an adverse reaction, occurring in 2.2% of patients treated with pregabalin, which may be related to the nervous system disorders.

• Nervous system disorders such as somnolence, dizziness, disturbance in attention, and memory impairment are reported.
• Paresthesia is reported as an adverse reaction, but the specific cause is not stated. 2

From the Research

Causes of Frequent Leg Paresthesia

The causes of frequent leg paresthesia can be diverse and complex. Some of the possible causes include:

• Central nervous system abnormalities, such as ischemia, structural or compressive phenomena, infection, inflammation, or degenerative conditions 3
• Peripheral nervous system abnormalities, such as entrapment syndromes, metabolic disturbances, trauma, inflammation, connective tissue diseases, toxins, hereditary conditions, malignancies, nutritional deficiencies, and miscellaneous conditions 3
• Restless legs syndrome, venous insufficiency in the leg, propriospinal myoclonus, nocturnal leg cramps, peripheral polyneuropathy, and neuroleptic drug-induced akathisia 4
• Small fiber neuropathy, which can be caused by metabolic diseases, dysimmunity syndromes, and genetic abnormalities 5
• Load carriage-related paresthesias, such as rucksack palsy and digitalgia paresthetica, which can be caused by nerve injury, compression, traction, or irritation 6
• Multiple locations of nerve compression, which can cause persistent lower limb paresthesia, even after spinal neural decompression surgery 7

Specific Causes

Some specific causes of frequent leg paresthesia include:

• Entrapment syndromes, such as peroneal muscle herniations that can cause superficial peroneal nerve entrapments 7
• Metabolic disturbances, such as diabetes mellitus and glucose intolerance 5
• Genetic abnormalities, such as familial amyloidosis due to a transthyretin mutation, Fabry disease, and sodium channel diseases 5
• Toxins and hereditary conditions, which can cause peripheral polyneuropathy 3
• Connective tissue diseases, such as Sjögren's syndrome and sarcoidosis 5

Diagnostic Approach

A thorough diagnostic approach is necessary to determine the underlying cause of frequent leg paresthesia. This may include:

• Detailed questioning of the patient to distinguish between different differential diagnoses 4
• Laboratory and radiologic studies to confirm the diagnosis and establish an etiology 3
• Specialty evaluations by a physical therapist, podiatrist, or other healthcare provider to rule out entrapment neuropathies 6