Alcoholic polyneuropathy is a form of peripheral neuropathy that may develop in people with long-term, excessive alcohol consumption. It causes damage to the peripheral nerves and most commonly presents with numbness, burning sensations, neuropathic pain, tingling, and weakness in the legs.

Its development is considered multifactorial. The direct toxic effects of alcohol and its metabolites on the nerves may occur alongside nutritional deficiencies, particularly deficiencies of vitamins that are essential for the normal functioning of the nervous system.

In most cases, symptoms begin gradually in the feet and lower limbs and may, over time, progress upwards or eventually involve the upper limbs.

Symptoms of Alcoholic Polyneuropathy

Alcoholic polyneuropathy is usually a symmetrical, length-dependent polyneuropathy, which explains why symptoms typically begin in the most distal parts of the lower limbs.

The most common symptoms may include:

• numbness in the feet and legs
• tingling or abnormal sensations (paresthesia)
• burning sensations
• neuropathic pain
• increased sensitivity to pain
• allodynia, meaning pain caused by a normally non-painful stimulus
• reduced sensation of touch or vibration
• muscle cramps
• muscle weakness
• reduced or absent reflexes
• difficulty walking
• unsteadiness and balance problems

In more advanced cases, muscle weakness and sensory disturbances may significantly affect the patient’s mobility and independence.

Neuropathic Pain and Alcoholic Neuropathy

Neuropathic pain is an important symptom in many patients with alcoholic polyneuropathy.

The pain may be described as:

• burning
• prickling or pins-and-needles sensations
• electric shock-like sensations
• sharp or stabbing pain
• pronounced sensitivity to touch

It is often more severe in the feet and lower limbs and may interfere with sleep, walking, and everyday activities.

Correctly identifying the neuropathic nature of the pain is important because its treatment differs from that of typical musculoskeletal pain.

Causes and Mechanisms of Alcoholic Polyneuropathy

Alcoholic polyneuropathy is not necessarily caused by a single mechanism.

Long-term excessive alcohol consumption can cause direct toxic damage to peripheral nerve axons.

At the same time, nutritional problems and impaired absorption of nutrients may coexist, resulting in deficiencies of vitamins and other nutrients that are important for normal nerve function.

Thiamine (vitamin B1) is particularly important, as its deficiency can cause significant neurological complications. Depending on the clinical presentation, assessment for other nutritional deficiencies may also be required.

Walking and Balance Problems

Patients with alcoholic polyneuropathy may experience difficulty walking and problems with balance.

This may result from a combination of:

• reduced sensation in the feet
• impaired proprioception
• muscle weakness
• neuropathic pain

People with chronic excessive alcohol consumption may also have other neurological disorders, including cerebellar involvement, which can further impair balance and coordination.

For this reason, unsteadiness should not automatically be attributed solely to peripheral neuropathy.

Involvement of the Autonomic Nervous System

In some patients, the nerve fibres of the autonomic nervous system may also be affected.

Possible symptoms include:

• abnormal sweating
• dizziness or weakness when standing up
• orthostatic hypotension
• changes in blood pressure
• gastrointestinal disturbances
• urinary problems
• sexual dysfunction

These symptoms can have many other causes and therefore require appropriate clinical evaluation.

Diagnosis of Alcoholic Polyneuropathy

The diagnosis of alcoholic polyneuropathy is based on the patient’s medical history, the characteristics of the symptoms, and a detailed neurological examination.

The assessment may include evaluation of:

• the distribution of sensory symptoms
• muscle strength
• tendon reflexes
• sensation to touch, pain, and vibration
• walking and balance
• the duration and amount of alcohol consumption
• the patient’s nutritional status
• the presence of other conditions that may cause polyneuropathy

It is important to investigate other possible causes of peripheral neuropathy, even when there is a history of long-term alcohol consumption.

Electromyography in Alcoholic Polyneuropathy

Electromyography and Nerve Conduction Studies (EMG/NCS) can help confirm and characterize peripheral neuropathy.

These examinations can provide information about:

• the type of nerve damage
• the distribution of the polyneuropathy
• the severity of nerve involvement
• the presence of both motor and sensory involvement
• other possible neurological causes of the symptoms

Alcoholic polyneuropathy frequently demonstrates features of an axonal sensorimotor polyneuropathy.

Laboratory Investigations

Laboratory investigations are individualized according to the patient’s medical history and clinical presentation.

They may be used to assess the patient’s general health and identify possible nutritional or metabolic factors, as well as to exclude other common causes of polyneuropathy.

Depending on the individual case, investigations may assess:

• blood glucose levels and possible diabetes mellitus
• vitamin levels and nutritional deficiencies
• thyroid function
• liver and kidney function
• hematological abnormalities
• other metabolic or systemic conditions

The diagnostic work-up is adapted to the individual characteristics of each patient.

Treatment of Alcoholic Polyneuropathy

The treatment of alcoholic polyneuropathy focuses primarily on addressing the cause of the nerve damage and managing the symptoms that have already developed.

A central component of treatment is stopping alcohol consumption, as continued exposure may result in further damage to the peripheral nerves.

The overall treatment approach may include:

• safe management of alcohol dependence when present
• correction of nutritional and vitamin deficiencies
• appropriate nutritional support
• medication for neuropathic pain
• physiotherapy
• muscle-strengthening exercises
• gait and balance training
• prevention of falls and injuries
• treatment of possible autonomic nervous system symptoms

In people with physical alcohol dependence, abruptly stopping alcohol consumption can cause a potentially serious alcohol withdrawal syndrome. Therefore, when such a risk is present, alcohol cessation should be carried out with appropriate medical supervision.

Recovery from Alcoholic Polyneuropathy

The progression of alcoholic polyneuropathy varies considerably between patients.

Early recognition of the neuropathy, cessation of harmful alcohol consumption, correction of nutritional deficiencies, and appropriate rehabilitation can help stabilize the condition and, in many patients, may lead to gradual improvement.

However, when nerve damage is severe or has been present for a long period, some symptoms may persist.

Peripheral nerve recovery is a slow process, and improvement may take several months.

Neurological Follow-Up of Alcoholic Polyneuropathy

Regular neurological follow-up helps assess the progression of polyneuropathy, muscle strength, sensation, walking ability, and response to treatment.

Particular attention is required when there is rapidly progressive muscle weakness, significant deterioration in walking, frequent falls, newly developed coordination problems, confusion, or other neurological symptoms, as these may indicate another or an additional neurological disorder.

Accurate diagnosis and individualized treatment of alcoholic polyneuropathy can help limit further nerve damage, reduce neuropathic pain, and improve mobility, functional independence, and overall quality of life.