Sensory neuropathy of the lower and upper extremities

Damage to peripheral nerves with impaired sensitivity is sensory neuropathy. Let's consider the main causes of the disease, types, symptoms, and treatment methods.

Neuropathy is a disease that occurs when nerves malfunction. According to the International Classification of Diseases ICD-10, this pathology belongs to category VI Diseases of the nervous system.

G60-G64 Polyneuropathies and other disorders of the peripheral nervous system:

• G60 Hereditary and idiopathic neuropathy.
• G61 Inflammatory polyneuropathy.
• G62 Other polyneuropathies.
• G63 Polyneuropathy in diseases classified elsewhere.
• G64 Other disorders of peripheral nervous system. Peripheral nervous system disorder NEC.

Structural disorders in the central and peripheral parts of the nervous system manifest themselves as trophic and vegetative-vascular disorders in the distal parts of the extremities, impaired sensitivity, and peripheral paralysis. In particularly severe cases, the muscles of the trunk and neck are involved in the pathological process.

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Epidemiology

According to medical statistics, sensory neuropathy is diagnosed in 2% of people. In elderly patients, the rate of polyneuropathy is more than 8%. One of the main causes of the disease is diabetes, hereditary predisposition, chronic deficiency of vitamin B, traumatic injuries and severe intoxication of the body.

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Causes sensory neuropathy

Neuropathy develops due to the action of many factors. In most cases, damage to peripheral nerves is caused by the following reasons:

• Disorders of the body's immune system. The immune system produces antibodies, attacks its own immune cells and nerve fibers.
• Metabolic disorders.
• Intoxication.
• Tumor diseases.
• Various infections.
• Systemic pathologies.

Isolated sensory disturbances are extremely rare. Their occurrence is most often caused by damage to thin and/or thick nerve fibers.

Sensory neuropathy in diabetes

One of the serious complications of diabetes mellitus type 1 and 2 is sensory neuropathy. About 30% of patients with diabetes face this problem. The pathology is characterized by sharp burning pains, crawling ants on the skin, numbness of the legs and their muscle weakness.

Diabetic neuropathy has several types:

• Peripheral – symmetrical (sensory, distal), asymmetrical (motor, proximal), radiculopathy, mononeuropathy, visceral.
• Central – encephalopathy, acute neuropsychiatric disorders due to metabolic decompensation, acute cerebrovascular accident.

The therapy process begins with a comprehensive diagnosis aimed at establishing the causes and mechanism of the disease. Patients are shown strict regulation of blood sugar concentration, the use of antioxidant, vascular, metabolic drugs. In case of severe pain syndrome, painkillers are prescribed. Early diagnosis and treatment can reduce the risk of complications. It is impossible to completely cure the pathology.

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Risk factors

The development of neuropathy can be triggered by the following factors:

• Acute deficiency of B vitamins – these substances are necessary for the proper functioning of the nervous system. Deficiency of nutrients over a long period of time leads to polyneuropathy and other pathologies.
• Genetic predisposition – some metabolic disorders of a hereditary nature can cause damage to nerve fibers.
• Endocrine diseases – diabetes mellitus disrupts the functioning of the vessels responsible for nerve nutrition. This leads to metabolic changes in the myelin sheath of nerve fibers. If the disease is caused by diabetes mellitus, neuropathy affects the lower extremities.
• Intoxication of the body - nerve damage can be caused by chemicals, various medications, alcohol. People with infectious diseases are at risk. When the body is poisoned by carbon monoxide or arsenic, the disease develops in a very short period of time. In some cases, the disease is a complication/side effect of taking medications.
• Traumatic injuries - various injuries and surgical interventions that damaged nerve fibers can cause not only sensory neuropathy, but also polyneuropathy. Most often, pathological symptoms are observed in diseases of the spine (osteochondrosis, herniated discs).
• Pregnancy - a specific reaction of the immune system to the fetus, vitamin and mineral deficiency, toxicosis and other factors can cause nerve damage. Neuropathy occurs at any stage of pregnancy.

To reduce the risk of developing the disease, the effects of the above factors should be eliminated or minimized.

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Pathogenesis

The mechanism of development of neuropathy depends on its underlying cause, therefore the pathogenesis is represented by two pathological processes:

• Axon damage (axial cylinder of nerve fiber) – in this case, the functioning of nerve and muscle cells is disrupted. Nerves with long axons are involved in the pathological process, which leads to denervation changes in the muscle. It occurs due to the effect of genetic, exogenous or endogenous factors on the nerves.
• Demyelination of nerve fiber is a disruption of nerve impulse conduction, which entails a decrease in the speed of conduction along the nerve. Against this background, muscle weakness develops, early loss of tendon reflexes without muscle atrophy. In most cases, demyelination is associated with autoimmune processes, the formation of antibodies to immune cells, genetic abnormalities, and intoxications.

Both pathological processes are interconnected. Since secondary demyelination occurs with axonal damage, and axonal disorder develops with demyelination of the nerve fiber. Diabetic sensory neuropathy develops after acute carbohydrate metabolism disorder or rapid compensation of hyperglycemia with insulin.

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Symptoms sensory neuropathy

Impaired sensitivity develops due to various reasons and factors. The pathology has several types and forms, but they all have similar symptoms:

• Muscle weakness of the upper and lower limbs.
• Swelling of the legs and arms.
• Goosebumps, burning, paresthesia and other strange sensations in the extremities.
• Decreased sensitivity in the arms and legs.
• The appearance of unexplained pain and discomfort.
• Trembling of fingers, involuntary twitching of muscles.
• Increased sweating.
• Loss of coordination, dizziness.
• Slow wound healing.
• Increased heart rate.
• Respiratory disorders.

Sensory neuropathy begins to manifest itself from the fingers and toes. Gradually, the pathological process moves upward. In particularly severe cases, both the arms and legs of patients are atrophied, which leads to their disability.

Sensory manifestations of the disease can be positive and negative. The former include:

• Heightened perception of pain.
• Burning.
• Paresthesia.
• Increased sensitivity to tactile stimuli.
• Acute pain syndrome.

As for negative sensory symptoms, this is a decrease in sensitivity in the limbs and lower abdomen. Most often, the negative form develops with an acute deficiency of vitamins E and B12. Patients experience movement disorders and severe weakness in the limbs. The pathological process may involve the muscles of the head, neck, pharynx, and upper body. Patients experience painful cramps and uncontrollable muscle twitching.

The above symptoms can be both pronounced and weak. In most cases, neuropathy develops over several years, but it can appear suddenly, within a couple of weeks.

Sensory signs of neuropathy depend entirely on the degree of involvement of nerve fibers in the pathological process.

• If large peripheral nerves are affected, then there is a decrease in sensitivity to light touch. Patients develop an unsteady ataxic gait and weakness of the deep muscles of the limbs.
• When small nerve fibers are damaged, temperature and pain sensitivity decrease. This increases the level of trauma.

Many patients report spontaneous pain and contact paresthesia, which indicate simultaneous damage to all types of nerve fibers. As the disease progresses, the pathological process involves the endings of the short nerves of the trunk, chest, and abdomen.

Motor sensory neuropathy

Charcot-Marie-Tooth disease or motor-sensory neuropathy is a peripheral nerve injury with impaired sensitivity. The pathology is characterized by progressive polyneuropathy with damage to the muscles of the distal extremities. In most cases, the disease has a genetic origin.

The first signs of the disorder appear at the age of 15-30 years. Weakness and atrophy of the muscles of the distal parts of the upper limbs appear. Gradually, the muscles of the distal parts of the legs are involved in the pathological process. Tendon reflexes from the arms quickly atrophy, the knee and Achilles reflexes decrease. All patients develop foot deformities.

As the pathology progresses, all types of sensitivity decrease. Some patients develop signs of static and dynamic cerebellar ataxia. The proximal parts of the legs and the development of scoliosis may be involved in the pathological process.

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Hereditary sensory neuropathy

According to studies, about 70% of neuropathies are hereditary. The genetically heterogeneous disease occurs with progressive damage to the peripheral nerves.

Clinical manifestations of the disease:

• Weakness and atrophy of the muscles of the distal extremities.
• Deformation of limbs.
• Impaired sensitivity.
• Tendon hypo/areflexia.
• Coordination disorders.

This form of sensory neuropathy has a pronounced similarity with other types of this disease, so it requires differentiation at the clinical level. Treatment and prognosis of the disease depend on its early diagnosis.

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Peripheral sensory neuropathy

Damage to peripheral nerves leads to impaired sensitivity. The disease develops due to many reasons, among which the most common are:

• Nerve trauma.
• Tumor lesions.
• Immune disorders.
• Intoxication.
• Acute vitamin deficiency in the body.
• Vascular diseases.
• Vasculitis.
• Blood diseases.
• Metabolic disorders.

Peripheral nerve damage occurs in endocrine diseases, viral and bacterial infections, drug intoxications. The presence of a huge number of possible risk factors significantly complicates the process of identifying the root cause.

Signs of peripheral nerve damage:

• Atrophy of the muscles of the limbs.
• Weakness in the arms and legs.
• A burning sensation and paresthesia in the hands and feet.
• Decreased or absent reflexes.
• Peripheral paralysis.

To establish a diagnosis, a comprehensive examination of the patient is carried out. The patient is prescribed CT, MRI, neuroelectromyography, skin/nerve biopsy. For treatment, medications, physiotherapy and various rehabilitation methods are used, aimed at restoring motor functions and nerve sensitivity.

Distal sensory neuropathy

This type of disease is most often one of the forms of diabetic polyneuropathy and occurs in 33% of people with diabetes. The pathology is manifested by symmetrical damage to the lower extremities. There is a loss of sensitivity, pain and tingling of varying intensity. Atrophy of the foot muscles is also possible.

Sensory symptoms and pathological signs dominate over motor ones. When large fibers are affected, sensitivity to light touch decreases. This leads to impaired coordination and development of weakness of the deep muscles of the extremities.

If small nerve fibers are damaged, pain and temperature sensitivity decreases. The disease develops slowly, so early detection reduces the risk of ulcers and other life-threatening complications.

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Sensory neuropathy of the extremities

One of the possible causes of limb sensitivity disorders is sensory neuropathy. Nerve disease most often occurs against the background of metabolic disorders in the body. Damage to nerve fibers is characterized by the following symptoms:

• Loss of sensitivity.
• Numbness in arms and legs.
• Insensitivity to cold, heat, and tactile impact.

But in some cases, sensitivity, on the contrary, becomes acute and pronounced. Neuropathy of the lower extremities is more common than that of the upper extremities. This is due to increased stress on the legs. At the same time, the causes and symptoms of damage to both the upper and lower extremities are similar.

In most cases, muscle cramps occur, due to a disruption in the skin's nutrition, dryness appears and protective functions are reduced. In combination, this leads to a slowdown in the healing of various injuries, minor purulent processes. Treatment begins with identifying the cause of the disease. Often, this is diabetes and hereditary predisposition. All patients are prescribed B vitamins, painkillers and antidepressants.

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Sensory neuropathy of the lower extremities

Nerve fibers are divided into several types: motor, sensory and vegetative. Damage to each of them has its own symptoms. Sensory neuropathy of the lower extremities is characterized by damage to sensory nerve fibers.

The main causes of the disease include:

• Hereditary predisposition.
• Autoimmune diseases.
• Tumor lesions.
• Drug intoxication.
• Metabolic disorders.
• Alcohol abuse.
• Diabetes mellitus.
• Poisoning of the body.
• Impaired kidney and liver function.

Depending on the cause of the damage to the peripheral nerve fibers, the following types of neuropathy of the legs are distinguished: dysmetabolic, toxic, diabetic, alcoholic. The success of the treatment of the pathology depends on the identification and elimination of its root cause.

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Sensory axonal neuropathy

Sensory axonal neuropathy is a disease with damage to sensitive nerve fibers. It develops against the background of endocrine pathologies, vitamin deficiency, immune system failure, after acute intoxication and due to a number of other reasons.

The main manifestations of axonal neuropathy:

• Spastic and flaccid paralysis of the limbs.
• Muscle twitching and cramping.
• Changes in sensitivity: tingling, burning, paresthesia.
• Circulatory disorders: swelling of the extremities, dizziness.
• Impaired coordination.
• Changes in tactile, temperature and pain sensations.

Electroneuromyography is performed to diagnose the pathological process and identify its localization. This procedure helps to determine the degree of damage to nerve tissue. Treatment is complex, aimed at eliminating the cause of the disease and preventing possible complications.

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Forms

There are several forms of neuropathy, one of them is sensory, which is characterized by the involvement of sensory nerve fibers in the pathological process (numbness, pain, burning). Most often, sensory impairment of sensitivity is distal and symmetrical.

Let's consider the main types of neuropathies, taking into account the types of affected sensory fibers:

1. Sensory neuropathy with damage to large nerve fibers:

• Diphtheria
• Diabetic
• Acute sensory ataxic
• Dysproteinemic
• Chronic inflammatory demyelinating
• Against the background of biliary cirrhosis of the liver
• In critical conditions.

2. With predominant damage to thin nerve fibers:

• Hereditary (amyloid, autonomous)
• Idiopathic
• Diabetic
• MGUS neuropathies
• For diseases of connective tissue
• For vasculitis
• Paraneoplastic pathologies
• Against the background of renal failure
• In sarcoidosis
• Intoxications
• HIV infections.

Each type of disease requires complex diagnostics with the study of pathogenesis links. The treatment process depends on the stage and severity of the pathology.

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Motor sensory neuropathy type 1

This type of isolated nerve damage is related to congenital degenerative diseases. Motor-sensory neuropathy type 1 is a demyelinating or pseudohypertrophic pathology. It is characterized by a decrease in the speed of impulse conduction with the formation of thickenings in the myelin sheath, which alternate with remyelination and demyelination areas.

Another feature of this form of nerve disease is its mild course, when the patient's symptoms include slight deformation of the foot and areflexia.

To confirm the diagnosis, the doctor carefully studies the dissociation between the existing symptoms and the absence of active complaints. An analysis of the family history, a set of laboratory and instrumental studies are also carried out. Treatment and prognosis depend on the stage of the disease, its causes, and the presence of complications.

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Motor sensory neuropathy type 2

The second type of motor-sensory sensitivity disorder is axonal neuropathy. It is characterized by normal or decreased speed of impulse conduction along the median nerve. The symptoms of the disease may be blurred, and changes in the myelin sheath may be absent.

The first pathological symptoms make themselves known in adolescence or early adulthood. The severity of the disorder is determined by family history. In some cases, the second type of motor-sensory disorder leads to disability and limitation of the patient's ability to work.

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Complications and consequences

Nerve damage is a rather dangerous disease. It does not go away on its own and if left untreated, it will lead to serious consequences. Possible complications of the disease:

• Decreased muscle tone.
• Muscle atrophy.
• Formation of ulcerative lesions on the skin.
• Paralysis of the limbs.
• Respiratory disorders due to dysfunction of the nerves responsible for the functioning of the respiratory muscles.

Progressive pathology completely changes a person's usual way of life. The patient loses the ability to take care of himself and work. Disability very often leads to anxiety and depressive states. In especially severe cases, when the function of the nerves regulating the work of the heart is impaired, death is possible due to a heart rhythm disorder.

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Diagnostics sensory neuropathy

To detect sensory nerve disease, a comprehensive examination is carried out. Diagnostics consists of:

1. Collection of anamnesis and analysis of patient complaints:

• When painful symptoms first appeared.
• Presence of intoxication, alcohol abuse.
• Presence of diabetes mellitus.
• Nutritional features.
• Recent medication use.
• The presence of infectious and any other diseases of the body.
• Hereditary predisposition.
• Features of the profession (whether the work is related to chemicals).

2. A thorough physical and neurological examination to identify abnormalities characteristic of the disease. Examination of pain, temperature and deep sensitivity.
3. Laboratory tests: glucose levels, urea, creatine, blood test for toxins and heavy metal salts.
4. Instrumental diagnostics: X-ray, electroneuromyography, nerve biopsy.

A number of specialists are involved in the diagnosis of the disease. Particular attention is paid to therapeutic and endocrinological studies.

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Tests

Standard laboratory testing for suspected sensory neuropathy includes:

• Complete blood count.
• ESR.
• Urine analysis.
• Evaluation of changes in plasma glucose levels after and before meals.
• Electrophoresis of serum proteins.

The tests can detect diabetes, renal/liver failure, metabolic disorders, vitamin deficiency, signs of pathological activity of the immune system and other possible causes/complications of the disease.

Further examination tactics depend on the results of physical, instrumental and differential examination.

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Instrumental diagnostics

To identify nerve damage of various localizations and stages, complex instrumental diagnostics are indicated.

• Computer tomography – visualizes organs, bone and soft tissues. Allows to identify bone or vascular changes, tumor lesions, cysts, hernias, spinal stenosis, encephalitis and other disorders.
• Magnetic resonance imaging is aimed at studying the condition and size of muscle tissue, identifying compression effects on nerve fibers, and determining areas of muscle tissue replacement with fat.
• Electromyography is a measurement of the electrical activity of muscles at rest and under tension. To perform the procedure, a thin needle is inserted into the muscle. The speed of impulse conduction along the nerves allows us to determine the degree of damage to large nerve fibers. If there is a blockage of the impulse or a slow speed of its transmission, this indicates damage to the myelin sheath. A decrease in the level of impulses is one of the signs of axonal degeneration.
• Nerve biopsy is the removal and examination of a sample of nerve tissue. The sample is most often taken from the shin. This procedure is performed in rare cases, as it can itself cause neuropathic complications.
• Skin biopsy – the doctor removes a small piece of tissue to examine the nerve endings. This method is less traumatic than a nerve biopsy, is easier to perform, and has fewer side effects.

The above methods are used both for diagnosis and during treatment to monitor its effectiveness.

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Differential diagnosis

Sensory neuropathy is differentiated from myopathic conditions, i.e. chronic progressive neuromuscular pathologies. The disease is compared with various congenital pathologies, anomalies in the development of muscle and bone tissue.

Differentiation between different types of polyneuropathies is also carried out. A complex of both laboratory and instrumental methods is used to establish a diagnosis.

Treatment sensory neuropathy

The treatment methods for sensory neuropathy depend on the causes, severity of painful symptoms and type of nerve damage.

1. The first stage of treatment begins with eliminating the causes of the disease:

• Normalization of blood glucose levels.
• Giving up alcohol.
• Stopping contact with toxic substances.
• Surgical removal of tumors followed by chemotherapy.
• Treatment of infectious diseases.

2. At the second stage, non-specific therapy is carried out, aimed at improving nutrition and restoring damaged nerve fibers. For this purpose, patients are prescribed group B drugs and metabolics, that is, drugs that improve tissue nutrition.
3. The final stage of treatment is symptomatic therapy. If the pathology is accompanied by painful sensations, the patient is prescribed painkillers. Hypotensive drugs are used to normalize blood pressure.

In cases of severe muscle weakness and atrophy, orthoses are used, i.e. supporting devices that help move. In some cases, surgical intervention is performed to release the clamped muscle fibers. There are also physiotherapeutic methods that speed up the patient's rehabilitation process.

Prevention

To reduce the risk of developing diseases with nerve damage, you should follow these recommendations:

1. Minimize exposure to any factors that can cause illness.

• Giving up alcohol.
• Blood glucose control for diabetics.
• Use of medications only as prescribed by a doctor, in compliance with all recommendations for their use.
• Use of protective equipment when working or in prolonged contact with toxic substances.

2. Timely treatment of any diseases of the body. Do not neglect viral and infectious diseases.
3. Control the quality of food products. Constant intoxication triggers the processes of destruction of the body and causes disturbances in the functioning of nerve fibers.
4. Regular physical activity, preventive massages.

Prevention is aimed at eliminating the causes of pathology and maintaining a healthy lifestyle. But with hereditary factors, preventive measures are powerless.

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Forecast

Sensory neuropathy has a very low mortality rate, but complete recovery from this pathology is rare. The prognosis of the disease depends on many factors. In hereditary forms of the disease, it is rarely possible to achieve significant improvement in the painful condition, since the pathology progresses slowly, which complicates its early diagnosis. There is a risk of patient disability and loss of ability to work

Sensitivity disorders caused by endocrine pathologies have a favorable prognosis, provided that glycemia levels are controlled. With proper diagnosis and effective treatment, other types of sensory neuropathy also have a positive outcome.

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