Polyneuritis can be the result of: infections (eg: diphtheria), autoimmune diseases (eg: Guillain-Barré syndrome), the intake of certain drugs (eg: chemotherapy), exposure to certain toxic substances (eg: insecticides) , diabetes mellitus, alcoholism, some vitamin deficiencies, etc.
Acute or chronic, polyneuritis is responsible for different symptoms, depending on whether the inflamed nerves are sensitive, motor or mixed.
Diagnosing polyneuritis requires a "thorough investigation, an investigation that generally begins with the" physical examination and "history, and ends with instrumental tests such as electromyography and biopsy.
The presence of polyneuritis requires causal therapy, accompanied by symptomatic therapy.
Brief review of what "is a Nerve
Nerves are important structures of the nervous system, resulting from the grouping of several axons and having the important task of carrying nerve impulses.
An axon is the characteristic extension of neurons (the cells of the nervous system), which allows the diffusion of nerve signals even over a long distance.
Nerves can carry information in three ways:
- From the central nervous system (CNS) to the periphery. Nerves with this property are called efferents. The efferent nerves control the movement of muscles, so they are at the head of the motor sphere.
- From the periphery to the SNC. Nerves with this ability are called afferents. The afferent nerves signal to the CNS what they have detected in the periphery, therefore they cover a sensory (or sensory) function.
- From the SNC to the periphery and vice versa. Nerves with this double capacity are called mixed. Mixed nerves perform a double function: motor and sensory.
What is the peripheral nervous system?
The peripheral nervous system (PNS) is the "arm" of the central nervous system (CNS), ie the "mind". Its function, in fact, consists in transmitting to the CNS all that is captured inside (organs) and outside (skin) of the organism, and in spreading to the periphery all the elaborations originating in the CNS. In other words, the peripheral nervous system carries information from the peripheral districts of the human body to the central nervous system and vice versa.
Without the PNS, the central nervous system could not function properly.
Acute Polyneuritis and Chronic Polyneuritis: what are they and what differentiates them?
A polyneuritis can have the connotations of a condition:
- Acute, if symptoms appear quickly and are very severe, or
- Chronic, if the clinical manifestations arise gradually and are of moderate intensity.
Understanding what the name Polynevrite is
The definition of polyneurite is in the same term "polyneurite"; indeed:
- "poli-" means "a lot" (from ancient Greek "polus'),
- "neur-" is the word that calls to the nerves (from ancient Greek "neuron") And
- "-ite" is the suffix that, in medicine, refers to the inflammatory process.
- Some autoimmune diseases, including Guillain-Barré syndrome, rheumatoid arthritis, systemic lupus erythematosus, Sjögren's syndrome and chronic inflammatory demyelinating polyneuropathy. People with an autoimmune disease have an aggressive immune system against the body , to which it should, in fact, be protected;
- Prolonged use of certain drugs. Among the offending drugs are: chemotherapy for cancer (vinblastine and vincristine), some sedatives (barbital and hexobarbital), some antibiotics (sulfonamide and nitrofurantoin) and anticonvulsants for the treatment of "epilepsy (phenytoin);
- Cancers such as lymphoma or multiple myeloma. A lymphoma is a malignant tumor affecting the glandular apparatus that makes up the lymphatic system (lymph nodes). Multiple myeloma is a malignant tumor affecting certain cells of the immune system. The latter, in fact, begins to produce an abnormal protein that causes kidney problems and damage to other organs and tissues in the body;
- Exposure to toxic substances, such as organophosphorus insecticides, tricresyl phosphate or thallium.
Causes of Chronic Polyneuritis
Under the heading "causes of chronic polyneuritis", there are:
- Diabetes mellitus. Caused by a defect in insulin secretion / action, diabetes mellitus is a metabolic disease that causes hyperglycemia.
Hyperglycemia has various effects on the human body, including damaging the blood vessels that supply the peripheral nerves and are essential for the good health of the latter.
- State of severe alcoholism. Alcoholics do not adequately absorb ingested foods and are often subject to episodes of diarrhea and vomiting; this determines a state of malnutrition, which also affects the vitamins essential for the good health of the peripheral nervous system. These vitamins are B12, B1, B6, niacin and E.
- Vitamin deficiencies due to causes other than alcoholism. The exclusion from the diet of the aforementioned vitamins (B12, B1 etc.), by choice or lack of availability, has the same effects on peripheral nerves as alcoholism.
- State of hypothyroidism. An underactive thyroid produces an insufficient amount of thyroid hormones for the needs of the body, including peripheral nerves.
- Chronic kidney disease. Malfunctioning of the kidneys results in a build-up of toxic substances in the body, which cause inflammation and also damage the peripheral nerves.
- Exposure to toxic substances, such as heavy metals or mercury.
- Excessive intake of vitamin B6. This is a rare but possible circumstance.
Types of Polyneuritis
Depending on the task for which the inflamed peripheral nerves are assigned, a polyneuritis can be of the following type: sensory, motor or mixed.
SENSITIVE POLYNEVRITIS
Doctors call polyneuritis sensory polyneuritis characterized by the simultaneous inflammation of several peripheral nerves with sensory function.
MOTOR POLYNEVRITIS
The definition of motor polyneuritis refers to polyneuritis characterized by the simultaneous inflammation of several peripheral nerves with motor function.
MIXED POLYNEVRITE
The heading "mixed polyneuritis" includes all forms of polyneuritis marked by "simultaneous inflammation of both sensory and motor nerves.
Epidemiology
According to statistics, people between the ages of 20 and 40 suffer most from polyneuritis.
Except when the cause is diphtheria, polyneuritis rarely affects children.
Typical symptoms of a sensitive polyneuritis
Episodes of sensory polyneuritis produce symptoms where inflamed spinal nerves have their own surface dendrites and receptors on the skin.
Virtually all parts of the body can show the results of a sensitive polyneuritis; however, the upper and lower limbs are the most affected areas of all.
Typical clinical manifestations of sensitive polyneuritis include:
- Tingling and tingling
- Sense of numbness and reduced ability to feel pain and temperature changes;
- Burning, stabbing pain
- Allodynia, or pain caused by a stimulus which, under normal conditions, would be completely harmless and without consequences;
- Loss of balance and coordination ability.
The painful sensation that characterizes sensory polyneuritis represents a form of neuropathic pain (or peripheral neuropathic pain).
Neuropathic pain is a different sensation than that due to a physical insult; in fact, it originates directly in the structures making up the nervous system (nerves, in the case of the PNS, and brain and spinal cord, in the case of the CNS).
Typical symptoms of a Motor Polyneuritis
Episodes of motor polyneuritis cause symptoms where the muscles controlled by the peripheral nerves that are subject to inflammation reside.
Typical manifestations of motor polyneuritis are:
- Muscle spasms and cramps;
- Muscle weakness and / or paralysis of a number of muscles;
- Inability to use muscles dependent on inflamed peripheral nerves;
- Reduction of muscle mass due to forced unused.
Motor polyneuritis mainly affects the upper and lower limbs, which, in the light of the aforementioned manifestations, can lead to difficulties in holding objects or walking problems.
Did you know that ...
A typical symptom of motor polyneuritis affecting the lower limbs is foot drop, ie the inability to keep the front part of the foot raised.
Typical symptoms of a mixed polyneuritis
Episodes of mixed polyneuritis include symptoms typical of sensitive polyneuritis and chronic polyneuritis.
Complications
Without proper treatment, peripheral nerves suffering from polyneuritis can be damaged; damage to the peripheral nerves has irreversible consequences, ie they undermine their integrity without the possibility of recovery.
When it results in peripheral nerve damage, polyneuritis can lead to various complications, including for example gangrene (it is the massive putrefaction of one or more tissues of the body).
Did you know that ...
In patients with diabetes mellitus, inadequately treated polyneuritis leads to the so-called diabetic foot.
When to see a doctor?
Especially for individuals at risk, the apparently unjustified appearance of symptoms such as tingling, numbness, loss of sensation, lack of balance, weakness and muscle weakness is a valid reason to consult a doctor or go to the nearest hospital. etc.
Important!
As a rule, the earlier a polyneuritis is identified, the greater the possibility of limiting its consequences.
, neurological evaluation, diagnostic imaging tests (CT and MRI), electromyography and / or biopsy of one or more peripheral nerves.A precise and meticulous diagnostic process allows to establish not only the presence of a polyneuritis, but also the characteristics of the inflammation in progress (whether it is motor, sensitive or mixed) and the causes that caused it.
Knowing the characteristics of a polyneuritis and, above all, tracing its causes is fundamental for planning the most effective therapy.
Blood analysis
In the context of polyneuritis, analyzes on a blood sample allow us to understand whether the patient owes his condition to diabetes mellitus, some vitamin deficiency or some thyroid dysfunction.
Neurological evaluation
During a neurological evaluation, the doctor analyzes tendon reflexes and assesses the presence or absence of neuromuscular and coordinative disorders.
CT scan and magnetic resonance
CT and nuclear magnetic resonance imaging (MRI) are able to highlight the peripheral nerves and, if necessary, show the "outcome of" inflammation in them.
Electromyography
Electromyography involves the study of the conduction of nerve signals along the area showing symptoms and, subsequently, the assessment of the electrical activity of the muscle or muscles in the same area.
In a context of polyneuritis, electromyography clarifies the typology of the inflamed peripheral nerves (whether motor, sensitive or mixed).
Biopsy of one or more Nerves
The biopsy of a nerve consists in the sampling and subsequent laboratory analysis of some cells of a nerve considered responsible for the symptoms in progress.
It can be useful for tracing the causes of inflammation.
The causal therapy of polyneuritis is essential to heal or, at least, prevent the inflammatory condition from worsening and causing irreparable damage to the nerves.
The earlier the causative therapy of polyneuritis is, the less likely it is that the inflammation will cause damage to the peripheral nerves involved.
Remember that peripheral nerve damage is irreparable.
Treatment of Neuropathic Pain
The management of neuropathic pain is one of the fundamental aspects of the symptomatic treatment of the most severe episodes of sensory polyneuritis.
For its implementation, special drugs are available, whose pain-relieving action is different from that of the drugs indicated in case of pain induced by trauma.
Among the drugs in question, they deserve a mention:
- Some antiepileptics, such as gabapentin and pregabalin;
- Some antidepressants, such as amitriptyline, doxepin, nortriptyline, duloxetine and venlafaxine;
- Tramadol, an opioid-type pain reliever;
- Capsaicin in cream.
For doctors, the main problem when prescribing drugs for neuropathic pain is the indication of the most appropriate dose; in general, the practice is to proceed by trial, as each patient responds differently (that is, it represents a case in itself standing).
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