Peripheral Neuropathy: Symptoms, Causes & Treatment

Peripheral neuropathy refers to damage or dysfunction of the peripheral nerves—the nerves distant from the brain and spinal cord that carry signals to the limbs. These nerves are responsible for sensation and muscle control, and when damaged, patients experience numbness, burning, or pain in the extremities, particularly the feet and hands.

Peripheral neuropathy is classified into several types: sensory neuropathy (affecting sensation), motor neuropathy (affecting muscle strength), mixed neuropathy (affecting both), and autonomic neuropathy (affecting involuntary functions such as heart rate and digestion). An estimated 2–3% of the global population suffers from peripheral neuropathy, and in the Middle East, including Jordan, prevalence is rising due to increased rates of type 2 diabetes.

The condition is chronic and requires long-term management. Early diagnosis and effective treatment can slow disease progression and improve patients' quality of life.

Symptoms of peripheral neuropathy vary depending on the type and severity of nerve damage. Symptoms typically begin in the feet and gradually progress upward. They may develop slowly over weeks or months, and symptoms may worsen at night. The presentation varies based on which nerves are affected.

• Numbness: Loss of sensation in the extremities, especially the feet and hands.
• Burning or sharp pain: Sensation of burning, tingling, or electrical pain in the limbs.
• Muscle weakness: Difficulty lifting objects or walking normally.
• Loss of balance: Instability while standing or walking.
• Heightened sensitivity: Even light touch causes pain (allodynia).
• Feeling of severe coldness: Especially in the feet.
• Inability to sense temperature: Loss of ability to perceive heat and cold.
• Non-healing wounds or ulcers: Because the patient cannot feel minor injuries.
• Coordination problems: Difficulty with fine motor tasks like writing or sewing.
• Nighttime numbness: Patient may awaken with pain.
• Paralysis: In severe cases (rare).
• Autonomic dysfunction: Such as irregular heartbeat or digestive issues (in autonomic neuropathy).

• Diabetes (most common): Persistently elevated blood glucose damages peripheral nerves gradually, especially with poor glycemic control.
• Vitamin B deficiency: Insufficient B12, folate, or thiamine impairs nerve health and causes neuropathy.
• Chemotherapy: Certain cancer drugs are neurotoxic and cause chemotherapy-induced peripheral neuropathy.
• Trauma and injuries: Direct nerve damage from accidents or fractures may cause permanent peripheral neuropathy.
• Infectious diseases: HIV, Ebola, Zika, and shingles weaken peripheral nerves.
• Liver and kidney disease: Organ failure causes toxic accumulation that damages nerves.
• Autoimmune and inflammatory diseases: Lupus, rheumatoid arthritis, and Guillain-Barré syndrome attack nerves.
• Alcohol abuse: Chronic alcohol use causes vitamin deficiency and directly damages nerves.

• Diabetes: Especially when poorly controlled for years.
• Age: More prevalent in people over 50 years old.
• High blood pressure: Increases nerve damage risk.
• Obesity: Associated with increased neuropathy risk.
• Family history: Certain hereditary neuropathies run in families.
• Smoking: Reduces blood flow to nerves.
• Excessive alcohol use: Directly damages nerves and causes vitamin deficiency.
• Chronic diseases: Liver failure, kidney disease, and chronic infections.
• Certain medications: Some antibiotics and antiretroviral drugs have neurotoxic side effects.
• Sedentary lifestyle: Physical inactivity worsens complications.

Diagnosis begins with a comprehensive physical examination and detailed medical history. The doctor will ask about symptoms and risk factors, then perform clinical tests and specialized studies to confirm diagnosis and identify the underlying cause.

• Clinical examination: Assessment of muscle strength, balance, and sensation using simple tools (needle, monofilament).
• Sensory testing: Tests measuring ability to feel pain, temperature, and vibration.
• Reflex testing: Checking reflexive responses (e.g., knee jerk).
• Blood tests: Checking blood glucose, vitamin B12, folate, lipids, hormones, liver, and kidney function.
• Nerve conduction studies and EMG: Measure electrical signal transmission speed along nerves. Normal conduction velocity typically exceeds 40–50 m/s.
• Magnetic resonance imaging (MRI): In complex cases or when suspecting other causes like nerve compression.
• Nerve biopsy: Small tissue sample in rare cases, especially for autoimmune diseases.
• Autonomic function testing: Such as blood pressure and heart rate measurements in different positions (for autonomic neuropathy).

Medications

• Pain relievers: Acetaminophen and ibuprofen for mild to moderate pain. Opioids may be used for severe cases with caution.
• Antidepressants: Amitriptyline and duloxetine alleviate neuropathic pain even without depression.
• Anticonvulsants: Gabapentin and pregabalin reduce electrical pain and burning sensations.
• Topical creams: Capsaicin or lidocaine cream applied to painful areas.
• Diabetes medications: Strict glycemic control if diabetes is the cause (target: fasting 80–130 mg/dL).
• Vitamin B supplementation: Replace B12, folate, and thiamine deficiency.
• Other medications: Treating underlying causes (hypertension, infections, etc.).

Procedures and Therapies

• Physical therapy: Strengthening and balance exercises to maintain muscle function.
• Occupational therapy: Teaching adaptive techniques for safe daily activities.
• Ultrasound therapy: May reduce pain and inflammation.
• Steroid injections: May be used to reduce inflammation around nerves.
• Transcutaneous electrical nerve stimulation (TENS): Sends mild electrical pulses to relieve pain.
• Compression therapy: Compression socks to improve circulation in the extremities.

Lifestyle Changes

• Diabetes control: Regular blood sugar monitoring and healthy diet (low sugar and simple carbs).
• Vitamin intake: Ensure adequate B vitamins from food or supplements.
• Avoid alcohol: Quit or significantly reduce alcohol consumption.
• Smoking cessation: Smoking reduces circulation and worsens symptoms.
• Regular physical activity: Walking, swimming, or yoga improves circulation and balance.
• Proper foot care: Daily foot inspection, careful nail trimming, comfortable footwear.
• Weight management: Weight loss reduces nerve pressure.
• Blood pressure and cholesterol control: Healthy diet, exercise, and medications if needed.
• Adequate sleep: Good sleep aids recovery.
• Stress management: Reduce stress to minimize pain flare-ups.

• Infections and non-healing wounds: Inability to sense injuries can lead to serious infections or gangrene, especially in the feet. Severe cases may require amputation.
• Pressure ulcers: Inability to feel pressure can cause deep wounds (bedsores) on limbs and sitting areas.
• Disability and mobility loss: Severe muscle weakness may prevent walking, requiring wheelchair use.
• Falls and accidents: Loss of balance and coordination increase fall risk and serious injuries, especially in elderly.
• Heart disease and stroke: Autonomic neuropathy affects heart rate and blood pressure control, increasing risk of heart attacks and strokes.
• Kidney and liver complications: If caused by renal or hepatic disease, these conditions may worsen.
• Depression and anxiety: Chronic pain and disability can lead to serious mental health problems.
• Sleep apnea: Severe autonomic neuropathy may cause breathing control dysfunction.

• Strict diabetes control: Regular blood sugar monitoring and medication compliance. Target: HbA1c below 7% (53 mmol/mol).
• Maintain healthy blood pressure: Goal below 130/80 mmHg. Limit salt and take medications as prescribed.
• Balanced diet: Rich in fruits, vegetables, and lean proteins. Avoid refined sugars, complex carbohydrates, and saturated fats.
• Check vitamin levels: Especially B12, folate, and thiamine. Supplement if necessary.
• Quit smoking and alcohol: Both damage nerves and reduce circulation.
• Regular physical activity: 150 minutes of moderate exercise weekly (walking, swimming, cycling).
• Proper foot care: Daily inspection, safe nail trimming, comfortable shoes, annual podiatrist visit.
• Maintain healthy weight: BMI 18.5–24.9. Lose excess weight gradually and safely.
• Regular screening: Annual comprehensive neuropathy exam, especially if diabetic or have other risk factors.
• Avoid neurotoxic medications: If alternatives exist, consult your doctor about drugs that may harm nerves.