1) Disease Description (Causes and Pathophysiology, Main Symptoms)
- Definition Summary
Polyneuropathy is a condition in which widespread damage to the peripheral nerves (sensory, motor, and autonomic nerves) causes symmetrical, distal-predominant sensory loss, pain, weakness, and autonomic symptoms. - Main Causes
- Metabolic: diabetes mellitus (most common), chronic kidney failure, liver cirrhosis, etc.
- Toxic/drug-related: alcohol, anticancer drugs, some antibiotics and antiretroviral drugs, etc.
- Nutritional deficiencies: vitamin B12, vitamin B1, etc.
- Infectious/immune-related: post-infectious or autoimmune causes (e.g., Guillain-Barré syndrome)
- Hereditary or other causes (peripheral vascular disease, associated tumors, etc.)
- Pathophysiology (Briefly)
Reduced nerve conduction function due to axonal degeneration (axonopathy), demyelination, or a combination of both results in impaired transmission of sensory and motor signals and autonomic dysfunction. - Main Clinical Symptoms
- Sensory: tingling in the hands and feet (mainly at night and in the distal areas), stabbing pain, burning sensation, reduced sensation
- Motor: decreased muscle strength, unsteady gait, muscle atrophy (in severe cases)
- Autonomic: orthostatic hypotension, abnormal sweating, urinary, bowel, and sexual dysfunction
- Diagnosis (Summary)
Medical history and neurological examination + nerve conduction studies (NCS)/electromyography (EMG) are standard. If necessary, blood tests (blood glucose·HbA1c, B12, TSH, liver and kidney function, electrolytes, serum protein electrophoresis), infectious and autoimmune testing, skin biopsy (when small-fiber neuropathy is suspected), etc. may be performed.
2) Treatment Methods and Precautions
- Treating the Cause (Top Priority)
- Diabetic neuropathy: metabolic control, including blood glucose, blood pressure, and lipid levels (the goal is to suppress progression through blood glucose management)
- Drug- or toxin-induced: discontinue or switch the causative drug, and stop alcohol consumption
- Nutritional deficiency: vitamin supplementation (e.g., supplementation in cases of B12 deficiency)
- Acute immune-mediated causes (e.g., Guillain-Barré syndrome): inpatient treatment, IVIG, or plasma exchange (plasmapheresis)
- Pain and Symptom Control (Symptomatic Treatment)
- First-line medications: tricyclic antidepressants (e.g., amitriptyline), SNRIs (e.g., duloxetine), anticonvulsants (gabapentin, pregabalin)
- Topical treatment: lidocaine patches (localized pain), capsaicin ointment (consider high-concentration topical capsaicin patches)
- Other: some medications such as tramadol are used on a limited basis (long-term use of opioids is not recommended)
- In chemotherapy-induced neuropathy, there is evidence that duloxetine provides some symptom relief
- Nonpharmacological and Supportive Treatment
- Physical therapy (balance and gait training, strengthening), orthopedic aids (walking aids and insoles), pain management programs (including cognitive behavioral therapy)
- Foot care (to prevent wounds in diabetic neuropathy), fall-prevention measures
- Complications and Precautions
- Skin damage and infection due to reduced sensation, depression and sleep disturbances due to chronic pain, falls due to gait disturbances, etc.
- Monitor medication side effects (sedation, weight changes, hypotension, gastrointestinal symptoms, etc.)
- If acute progressive weakness (e.g., respiratory muscle involvement) is suspected, immediate emergency evaluation is required
- Prognosis (Summary)
It varies greatly depending on the cause. If the cause can be treated, improvement of symptoms can be expected (e.g., discontinuing a drug or supplementing vitamins). For chronic causes such as diabetes or alcohol use, the goal is to suppress and manage worsening symptoms rather than achieve complete recovery.
3) Checklist Before an Outpatient Visit (Including Items to Prepare · Information to Tell the Doctor · Example Questions)
- Items to Prepare (Recommended to Bring)
- List of currently used medications and supplements (including dosage and administration times)
- Recent test results (blood glucose/HbA1c, kidney and liver function, vitamin B12, etc.) or copies of test reports
- Copies of previous nerve conduction study (NCS)/EMG results (if available)
- Symptom diary: onset, progression pattern (rapid/slow), times when symptoms are usually most severe, and factors that trigger or relieve symptoms
- Alcohol consumption amount and occupational history (possible toxic exposure), history of anticancer drug administration, etc.
- Important Information to Tell the Doctor First During the Outpatient Visit
- Recent history of acute infection, presence of breathing difficulties or acute muscle weakness, and whether any new medications were started or dosages changed
- Example Questions (Patient → Healthcare Provider)
- "Could any of the medications I am currently taking worsen neuropathy?"
- "What additional tests should I undergo?"
- "Which medication should I try first to control the pain?"
4) Examples of General Questions to Ask the Doctor
- What do you think is causing this disease? What additional tests are needed?
- What first-line medication do you recommend for pain control, and what are its side effects?
- Among lifestyle factors (exercise, diet, alcohol consumption, etc.), what should I pay particular attention to?
- What symptoms require me to come to the hospital immediately when my symptoms worsen (warning signs requiring emergency care)?
- What is the expected prognosis, and to what extent can the condition improve with treatment?
5) Examples of Disease-Specific Questions (1–2)
- When diabetes is suspected as the cause
- "What should my HbA1c target be, and to what extent can blood glucose control delay the progression of neuropathic symptoms?"
- When anticancer drugs or other medications are suspected as the cause
- "Could the medication I am currently receiving (or the anticancer drug I am scheduled to receive) cause neuropathy? Is alternative treatment or dose adjustment possible?"