Testing for Peripheral Neuropathy in the Feet

Understanding Peripheral Neuropathy

Peripheral neuropathy refers to damage of the peripheral nervous system, which connects the brain and spinal cord to the rest of the body. This extensive network of nerves is responsible for relaying messages about sensation and movement. When the peripheral nerves become damaged, there is disruption in how these signals are transported. The result is commonly felt in the furthest points from the central nervous system, especially the hands and feet.

What Causes Peripheral Neuropathy?

There are many potential causes of peripheral neuropathy. It may develop due to trauma or infection. Exposure to toxins, autoimmune disorders, vascular or metabolic problems like diabetes, nutritional deficiencies, and even some cancers or treatments can also lead to peripheral nerve damage.

Often there is no single identifiable cause. Many cases of peripheral neuropathy have no known origin. When a cause cannot be found, it is referred to as idiopathic peripheral neuropathy.

Common Forms of Peripheral Neuropathy

There are several classifications of peripheral neuropathy based on the type of nerves affected:

• Sensory neuropathy affects the nerves relaying physical sensations.
• Motor neuropathy affects the nerves controlling muscle movement.
• Autonomic neuropathy affects the nerves managing involuntary functions like blood pressure regulation and bowel movements.

Peripheral neuropathy can impact any of these nerve types. The most common is sensory neuropathy, which presents with symptoms like tingling, numbness, burning, or pain. When motor nerves are affected, it leads to loss of coordination and weakness in the extremities. Autonomic issues can cause problems with digestion, sexual function, bladder control, and blood pressure regulation.

Signs and Symptoms of Neuropathy in the Feet

Since peripheral neuropathy frequently manifests in the points furthest from the central nervous system, symptoms often first appear in the feet and hands. Common sensory complaints include:

• Tingling or prickling sensations
• Numbness or reduced ability to feel touch
• Burning or shooting pains
• Increased sensitivity to touch
• Lack of coordination or balance
• Muscle weakness
• Changes in skin texture or color
• Ulcers or open sores

The severity can range from mild to completely debilitating. Symptoms may be constant or intermittent, and they can fluctuate in intensity. Sometimes peripheral neuropathy follows a length-dependent pattern, where symptoms begin in the toes and feet, then spread upward as nerve damage progresses.

Why Catching Neuropathy Early Is Important

There are three main reasons why early evaluation of neuropathy is vital:

1. Establishing the cause - Diagnosing the underlying condition responsible for nerve damage can allow for targeted treatment to slow further progression.
2. Monitoring and prevention of complications - Sensory loss increases the risk of wounds or damage going unnoticed. Preventative foot care reduces complications.
3. Symptom management - Controlling discomfort can help maintain functionality and quality of life.

Even mild symptoms warrant medical assessment. Identifying peripheral neuropathy in its early stages gives the best chance to intervene and alter the course of the condition.

How is Peripheral Neuropathy Diagnosed?

Assessing possible peripheral neuropathy begins with a review of medical history, including any symptoms and their pattern of development. A doctor performs a physical exam concentrating closely on the extremities. This focuses on evaluation of reflexes and muscle strength and testing different sensory modalities like light touch, pain perception, vibration, temperature sensitivity and proprioception.

Common Diagnostic Tests

If clinical evaluation indicates peripheral neuropathy, further testing can help determine the type, severity and cause. Common diagnostic tools include:

• Blood tests checking vitamin levels, blood sugar, thyroid, kidney function, and antibodies signaling autoimmune conditions
• Imaging like MRI scans visualizing nerve or spinal issues
• Nerve conduction study sending small electric impulses along nerves to measure responsiveness
• EMG recording muscle and nerve electrical activity at rest and during contraction

These tests identify the pattern of neurological damage, assess severity, and guide treatment decisions. Results can also point towards underlying contributing factors to target.

Special Tests for Neuropathy in Feet

Sometimes testing focuses specifically on the nerves in the lower limbs when symptoms present in the toes or feet. Special tests like the following evaluate small fiber sensory function:

• Biopsy of skin from lower leg examining nerve fiber density
• Quantitative sensory testing using tools and standardized stimuli to map sensory thresholds
• Sudoscan device measuring sweat gland nerve function
• Corneal confocal microscopy looking at small sensory nerves in the eyes

These specialized tests identify even early small fiber neuropathy missed on routine nerve conduction studies.

Treatment Options for Peripheral Neuropathy

Treatment for neuropathy centers on controlling symptoms in addition to slowing the progression of nerve damage when possible. The foundation includes patient education on preventative foot care to avoid wounds or injuries and maximizing safety with accommodations for sensory loss or weakness. Patient self-care integrated with the appropriate medical treatment provides the best results.

Medications for Neuropathic Pain and Discomfort

Medications aim to reduce the most disruptive or disabling symptoms, typically pain. Options include:

• Over-the-counter pain relievers like nonsteroidal anti-inflammatories (NSAIDS), topical creams, or capsaicin
• Anti-seizure drugs like gabapentin or Lyrica (pregabalin)
• Antidepressants including SSNRIs and tricyclic antidepressants
• Opioid analgesics and anesthetics for severe symptoms
• Compounded topical medications when needed

Finding the most effective options with the fewest side effects involves some trial and error. Most patients utilize a multifaceted regimen for adequate symptomatic control.

Treatment Targeting Reversible Causes

When an underlying cause for peripheral neuropathy is identified, targeted treatment aims to slow further damage. Tight blood sugar control for diabetes, chemotherapy dose adjustments in cancer treatment, or IVIG for autoimmune neuropathy work to protect nerves from additional injury. Correcting nutritional deficiencies through diet or supplementation provides nerves the components needed to function and repair appropriately.

These cause-directed treatments coupled with the use of medications for symptom control provide the best opportunities to stall neuropathy progression and maintain quality of life.

Alternative Therapies as Complementary Approaches

Some patients find benefit from incorporating complementary techniques like:

• Physical therapy focusing on sensory retraining, balance exercises
• Occupational therapy maximizing safety with assistive devices
• Mindfulness, meditation or yoga for pain coping techniques
• Acupuncture for pain and inflammation modulation
• Electrostimulation methods like TENS units or infrared therapy

Using some of these modalities in conjunction with traditional medical treatment allows a multifaceted approach for the optimal control of neuropathy symptoms.

Preventing Neuropathy Progression

Patients diagnosed with peripheral neuropathy play an active role in monitoring symptoms and preventing escalation into further complications. Key prevention strategies include:

• Daily foot examinations looking for any lesions or wounds
• Proper footwear and custom orthotics to avoid pressure points and injury
• gentle exercises to retain mobility and flexibility
• Report any new numbness, pain or loss of function promptly

Implementing good foot care, follow up with providers, and sticking to the treatment plan gives nerves the best chance for recovery and helps prevent worsening damage over time.

Hope for Healing Peripheral Nerves

Research continues on potential future treatments to heal injured peripheral nerves. Stem cell therapy aims to stimulate nerve regrowth. Gene therapy may allow the delivery of specific nerve growth factors. Drug development targets promoting axon regeneration and suppressing fibrosis after nerve lesions. Bioengineered nerve conduits offer the potential for guiding and supporting re-growing nerves across damaged areas.

While complete restoration of lost nerve function remains challenging, the future looks promising. In the meantime, early evaluation and institution of appropriate therapies coupled with diligent patient self-care offers the best opportunity to halt peripheral neuropathy progression and maintain quality of life.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.