What is Neuropathy?
Neuropathy is a general term for damage or dysfunction of nerves. It can affect sensory, motor, or autonomic nerves and may occur in different parts of the body.
While diabetes is one of the most common causes, neuropathy can also result from a variety of other conditions and factors, including:
The symptoms of neuropathy vary depending on the type and cause but may include numbness, tingling, pain, muscle weakness, or problems with internal organ function.
Damage to nerve cells caused by diabetes is called “diabetic neuropathy.” About half of all people with diabetes are affected.
Nerves control many conscious and unconscious processes in our body:
The symptoms of polyneuropathy depend on which nerves are damaged. Because many different nerves are usually affected, it is referred to as “polyneuropathy.”
It usually begins in the feet and initially leads to abnormal sensations and pain, which worsen at rest and in warmth (e.g., at night in bed). As the damage progresses, the symptoms may disappear; pressure, pain, and heat are no longer felt. If dry skin (due to autonomic damage affecting sweating) and muscle wasting with deformities (due to motor damage) are also present, this is referred to as “diabetic foot syndrome.”
1) Sensorimotor polyneuropathy:
This refers to damage to sensory and motor nerve fibers.
Impairment of sensory nerve function manifests as disturbances in sensation (vibration, pressure, perception of warmth/cold, and pain), while impairment of motor nerve function leads to paralysis. The most important examination methods are testing vibration sensitivity with a tuning fork and testing reflexes with a reflex hammer.
2) Autonomic neuropathy:
This refers to damage to the autonomic (involuntary) nervous system, which controls the internal organs.
Signs may include: a persistently elevated heart rate, diarrhea or constipation, bladder emptying disorders, a significant drop in blood pressure upon standing, and erectile dysfunction in men. The diagnostic procedures are complex and are usually carried out by specialists for the respective organs.
The diagnosis of polyneuropathy is based on a combination of medical history, clinical examination, and additional diagnostic tests.
A detailed patient history focuses on symptoms such as numbness, tingling, pain, gait instability, and autonomic complaints. The clinical examination includes testing of sensory function (vibration, temperature, pain, and pressure), muscle strength, coordination, and reflexes.
The physician first asks about typical symptoms such as numbness, tingling, burning pain, reduced sensitivity to temperature, or a “pins and needles” sensation, especially in the feet. Symptoms often begin symmetrically and progress from the toes upward (“stocking distribution”). Questions about diabetes control, duration of the disease, alcohol use, medications, and other conditions are also important.
Electrophysiological studies, such as nerve conduction studies (NCS) and electromyography (EMG), are important tools to confirm the presence, type, and extent of nerve damage. In selected cases, additional tests such as quantitative sensory testing, autonomic function testing, or skin biopsy (to assess small nerve fibers) may be performed.
Laboratory tests are essential to identify underlying causes. These typically include blood glucose and HbA1c levels, vitamin B12, kidney and liver function, thyroid function, and screening for infections or autoimmune diseases.
Differential diagnosis of diabetic polyneuropathy
Diabetic polyneuropathy is primarily a diagnosis of exclusion. Although a length-dependent, symmetrical, distal sensorimotor neuropathy is typical for diabetes, other causes must be considered, especially if the presentation is atypical.
Features that may suggest alternative or additional causes include:
Important differential diagnoses include alcohol-related neuropathy, vitamin deficiencies (especially B12), toxic neuropathies, chronic inflammatory demyelinating polyneuropathy (CIDP), hereditary neuropathies, and neuropathies associated with systemic diseases.
A careful evaluation of clinical features, laboratory findings, and electrophysiological results is necessary to distinguish diabetic neuropathy from other forms and to identify potentially treatable causes.
Physical and neurological examination
A focused neurological exam evaluates different nerve functions:
Overall, diagnosis is not based on a single test but on a combination of findings. Early and regular screening—especially in people with diabetes—is crucial to prevent complications such as foot ulcers and amputations.
The management of diabetic polyneuropathy focuses on three main goals:
1) Glycemic control
Strict and stable blood glucose control is the cornerstone of treatment. Good glycemic control can prevent or significantly delay the progression of neuropathy and may lead to an improvement in symptoms. This includes lifestyle measures, oral antidiabetic drugs, and/or insulin therapy as appropriate.
2) Pharmacological treatment of neuropathic pain
Neuropathic pain often requires specific medications, as conventional analgesics are usually insufficient.
First-line medications:
Second-line or adjunct therapies:
Opioids should be used cautiously and usually only if first-line therapies are insufficient.
Pathogenetic treatment (targeting nerve damage)
Oral: 600 mg daily for maintenance
3) Topical treatments
4) Physical and supportive therapies
Non-pharmacological approaches can complement medication:
5) Transcutaneous Electrical Nerve Stimulation (TENS)
TENS is a non-invasive treatment that uses low-voltage electrical currents to relieve pain.
How it works:
Electrodes are placed on the skin over the painful area. A portable device delivers electrical impulses that stimulate sensory nerves. This may reduce pain through:
Application:
TENS is generally well tolerated and can be particularly useful in patients who do not achieve sufficient relief with medication alone.
6) Treatment of autonomic complications
Autonomic neuropathy requires targeted therapy depending on the organ involved:
These treatments are usually initiated by specialists but require coordination by a general practitioner or diabetologist.
Overall, treatment of diabetic polyneuropathy is individualized and often requires a combination of pharmacological and non-pharmacological approaches to achieve optimal symptom control and prevent complications.
There is no single cure for diabetic polyneuropathy, but a combination approach—tight glucose control, lifestyle changes, symptom-oriented medication, and careful foot care—can significantly slow progression, reduce pain, and prevent serious complications.