Polyneuropathies — the heterogeneous group of diseases which is characterized by system damage of peripheral nerves. Polyneuropathies are subdivided on initially aksonalny and initially demiyeliniziruyushchy. Irrespective of polyneuropathy type her clinical picture is characterized by development of muscular weakness and an atrophy, decrease in tendinous reflexes, various violations of sensitivity (paresteziya, hypo - and a giperesteziya) arising in disteel departments of extremities, vegetative frustration. The important diagnostic point at establishment of the diagnosis of a polyneuropathy is definition of the reason of its emergence. Treatment of polyneuropathy has symptomatic character, the main objective is elimination of a causal factor.
Polyneuropathies — the heterogeneous group of diseases which is characterized by system damage of peripheral nerves. Polyneuropathies are subdivided on initially aksonalny and initially demiyeliniziruyushchy. Irrespective of polyneuropathy type her clinical picture is characterized by development of muscular weakness and an atrophy, decrease in tendinous reflexes, various violations of sensitivity (paresteziya, hypo - and a giperesteziya) arising in disteel departments of extremities, vegetative frustration. The important diagnostic point at establishment of the diagnosis of a polyneuropathy is definition of the reason of its emergence. Treatment of polyneuropathy has symptomatic character, the main objective is elimination of a causal factor or compensation of the main disease.
Etiology and pathogenesis of polyneuropathies
Irrespective of an etiologichesky factor at polyneuropathies reveal two types of pathological processes — damage of an axon and a demiyelinization of nervous fiber. At aksonalny type of defeat there is a secondary demiyelinization, at demiyeliniziruyushchy defeat the aksonalny component again joins. The majority of toxic polyneuropathies, the type SGB, NMSN II aksonalny type are initially aksonalny. The classical option of SGB, HVDP, paraproteinemichesky polyneuropathies, type NMSN I belong to initially demiyeliniziruyushchy polyneuropathies.
At aksonalny polyneuropathies mainly the transport function of the axial cylinder which is carried out by aksoplazmatichesky current which bears in the direction from motor-neuron to a muscle and back a number of the biological substances necessary for normal functioning of nervous and muscle cells suffers. The nerves containing the longest axons are involved in process first of all. Change of trophic function of an axon and aksonalny transport leads to emergence of denervatsionny changes in a muscle. Denervation of muscle fibers stimulates development at first of a terminal, and then and collateral sprauting, growth of new bombways and a reinnervation of muscle fibers that leads to change of structure.
At a demiyelinization there is a violation of saltatorny carrying out a nervous impulse therefore carrying out speed on a nerve decreases. Demiyeliniziruyushchy damage of a nerve is clinically shown by development of muscular weakness, early loss of tendinous reflexes without development of muscular atrophies. Existence of atrophies indicates an additional aksonalny component. Demiyelinization of nerves can be called by autoimmune aggression with formation of antibodies to various components of protein of a peripheral myelin, genetic disorders, influence of ekzotoksin. Injury of an axon of a nerve can be caused by impact on nerves of exogenous or endogenous toxins, genetic factors.
Classification of polyneuropathies
Today the standard classification of polyneuropathies does not exist. On a pathogenetic sign of a polyneuropathy divide on aksonalny (initially defeat of the axial cylinder) and demiyeliniziruyushchy (myelin pathology). On character of a clinical picture allocate motor, touch and vegetative polyneuropathies. However in pure form these forms are observed very seldom, reveal the combined defeat of two or three types of nervous fibers more often (motor and touch, touch and vegetative other).
On an etiologichesky factor of a polyneuropathy divide on hereditary (neural amyotrophy of Sharko-Mari-Tuta, Russi-Levi's syndrome, Dezherin-Sotta's syndrome, Refsum's disease and so forth), autoimmune (Miller-Fleshera's syndrome, the SGB aksonalny type, paraproteinemichesky polyneuropathies, paraneoplastic neuropathies, etc.), metabolic (diabetic polyneuropathy, an uraemic polyneuropathy, hepatic polyneuropathy, etc.), alimentary, toxic and infectious and toxic.
Clinical picture of a polyneuropathy
In a clinical picture of a polyneuropathy signs of defeat of motor, touch and vegetative fibers are, as a rule, combined. Depending on degree of an involvement of fibers of various type in the neurologic status motor, touch or vegetative symptoms can prevail. Defeat of motor fibers leads to development of sluggish paresis, damage of the top and lower extremities with disteel distribution of muscular weakness is typical for the majority of polyneuropathies, at long damages of an axon muscular atrophies develop. Disteel distribution of muscular weakness (more often in the lower extremities) which is more expressed in muscles-razgibatelyakh, than in muscles-sgibatelyakh is characteristic of aksonalny and hereditary polyneuropathies. At the expressed weakness of peronealny group of muscles develops (so-called "cock gait").
The acquired demiyeliniziruyushchy polyneuropathies can be shown by proximal muscular weakness. At a heavy current defeat of ChN and respiratory muscles can be noted that is most often observed at the syndrome to Giyena-Barra (SGB). Relative symmetry of muscular weakness and an atrophy is characteristic of polyneuropathies. Asymmetric symptoms are characteristic of multiple mononeuropathies: multifocal motor neuropathy, multifocal sensomotorny neuropathy of Sumner-Lewis. Tendinous and periostalny reflexes at a polyneuropathy usually decrease or drop out, first of all Achilles tendon reflexes decrease, at further development of process — knee and karporadialny, tendinous reflexes from two-headed and three-headed muscles of a shoulder can remain safe a long time.
Touch violations at a polyneuropathy are also most often rather symmetric, at first arise in disteel departments (as "gloves" and "socks") and extend proksimalno. In a polyneuropathy debut often reveal positive touch symptoms (a paresteziya, a dizesteziya, a giperesteziya), but at further development of process symptoms of irritation are replaced by symptoms of loss (gipesteziya). Defeat of thick miyelinizirovanny fibers leads to violations of deep-muscular and vibration sensitivity, defeat of thin miyelinizirovanny fibers — to violation of painful and temperature sensitivity of skin.
Violation of vegetative functions is most brightly shown at aksonalny polyneuropathies as vegetative fibers are nemiyelizirovanny. Observe loss symptoms more often: defeat of the sympathetic fibers going as a part of peripheral nerves is shown by dryness of integuments, violation of regulation of a vascular tone; defeat of visceral vegetative fibers leads to a dizavtonomiya (tachycardia, orthostatic hypotension, decrease in erectile function, violation of work of housing and public utilities).
Diagnostics of polyneuropathies
At identification of slowly progressing sensomotorny polyneuropathy debuting from peronealny group of muscles it is necessary to specify the hereditary anamnesis, especially presence at relatives of fatigue and weakness of muscles of legs, changes of gait, deformation of feet (high rise). At development of symmetric weakness of a razgibately brush it is necessary to exclude intoxication lead. As a rule, toxic polyneuropathies are characterized, besides neurologic symptoms, by the general weakness, increased fatigue and seldom abdominal complaints. Besides, it is necessary to find out what medicines are accepted/accepted by the patient to exclude a medicinal polyneuropathy.
Slowly progressing development of asymmetric weakness of muscles — a clinical sign of a multifocal motor polyneuropathy. Slowly progressing gipesteziya of the lower extremities in combination with burning sensation and other manifestations in feet is characteristic of a diabetic polyneuropathy. The uraemic polyneuropathy arises, as a rule, against the background of a chronic disease of kidneys (HPN). At development of the touch and vegetative polyneuropathy which is characterized by burning, dizesteziya against the background of sharp reduction of body weight it is necessary to exclude an amyloid polyneuropathy.
Lack of Achilles tendinous reflexes, the high arch of foot are characteristic of hereditary polyneuropathies prevalence of weakness of razgibatel of muscles of feet, . In later stage of a disease there are no knee and karporadialny tendinous reflexes, atrophies of muscles of feet, shins develop. The damage of muscles corresponding to an innervation of separate nerves without touch violations is characteristic of a multiple motor polyneuropathy. In most cases damage of the top extremities prevails.
Touch polyneuropathies are characterized by disteel distribution of gipesteziya. In initial stages of a disease the giperesteziya is possible. Sensomotorny aksonalny neuropathies are characterized by disteel gipesteziya and disteel muscular weakness. At vegetative polyneuropathies both the loss phenomena, and irritation of vegetative nervous fibers are possible. For a vibration polyneuropathy are typical , violations of a vascular tone of brushes, for a diabetic polyneuropathy, on the contrary, dryness of integuments, trophic violations, vegetative dysfunction of internals.
The research of antibodies to GM1 is recommended to conduct at patients with motor neuropathies. High credits (more than 1:6400) are specific to a motor multifocal neuropathy. Low credits (1:400-1:800) are possible at the chronic inflammatory demiyeliniziruyushchy poliradikulonevropatiya (CIDP), a syndrome Giyena-Barra and other autoimmune neuropathies. It is necessary to remember that the raised caption of antibodies to GM1 is revealed at 5% of healthy people (especially advanced age). Antibodies to the glycoprotein associated with a myelin reveal at 50% of patients with the diagnosis "a paraproteinemichesky polyneuropathy" and in certain cases other autoimmune neuropathies.
At suspicion on the polyneuropathies connected with intoxication lead, aluminum, mercury carry out blood tests and urine on the content of heavy metals. Carrying out the molecular and genetic analysis on all main HMCH I, IVA, IVB forms of types is possible. Carrying out a needle electromyography at polyneuropathies allows to reveal signs of the current denervatsionno-reinnervatsionny process. First of all, it is necessary to investigate disteel muscles of the top and lower extremities, and if necessary and proximal muscles. Carrying out a biopsy of nerves is justified only at suspicion on an amyloid polyneuropathy (identification of deposits of an amiloid).
Treatment of polyneuropathies
At hereditary polyneuropathies treatment has symptomatic character. At autoimmune polyneuropathies the purpose of treatment consists in achievement of remission. At diabetic, alcoholic, uraemic and other chronic progressing polyneuropathies treatment comes down to reduction of expressiveness of symptomatology and delay of a course of process. One of important aspects of non-drug treatment — the physiotherapy exercises directed to maintenance of a muscular tone and the prevention of contractures. In case of development of respiratory violations at a diphtheritic polyneuropathy carrying out IVL can be required. Effective drug treatment of hereditary polyneuropathies does not exist. As the supporting therapy use vitamin medicines and neurotrophic means. However, their efficiency is up to the end not proved.
For treatment of a porfiriyny polyneuropathy appoint glucose which usually causes improvement of a condition of the patient, and also anesthetics and other symptomatic medicines. Drug treatment of a chronic inflammatory demiyeliniziruyushchy polyneuropathy includes carrying out a membrane plasma exchange, use of immunoglobulin human or Prednisolonum. In some cases efficiency of a plasma exchange and immunoglobulin is insufficient therefore if there are no contraindications, treatment should be begun with glucocorticosteroids at once. Improvement occurs, as a rule, in 25-30 days; in two months it is possible to begin gradual decrease in a dose to supporting. At decrease in a dose of glucocorticosteroids carrying out EMG-control is necessary. As a rule, completely it is possible to cancel Prednisolonum within 10-12 months, if necessary it is possible "to make secure" azatiopriny (or , or mofetit a mikofenolat).
Treatment of a diabetic polyneuropathy is carried out together with the endocrinologist, his main objective is maintenance of normal level of sugar of blood. Apply tritsiklichesky antidepressants to knocking over of a pain syndrome, and also , , , carbamazepine. In most cases apply medicines of tioktovy acid and vitamins of group B. Regress of symptoms at an early stage of an uraemic polyneuropathy is reached by nephrologists at correction of level of uraemic toxins in blood (a program hemodialysis, transplantation of a kidney). From medicines group B vitamins are applied, at the expressed pain syndrome — tritsiklichesky antidepressants, .
The main therapeutic approach in treatment of a toxic polyneuropathy — the termination of contact with toxic substance. At dozozavisimy medicinal polyneuropathies it is necessary to correct a dose of the corresponding medicine. At the confirmed diagnosis "diphtheria" introduction of anti-toxic serum reduces probability of development of a diphtheritic polyneuropathy. In rare instances in connection with development of contractures and deformations of feet surgical treatment can be necessary. However it is necessary to remember that the long obezdvizhennost after surgery can negatively influence motive functions.
The forecast at a polyneuropathy
At a chronic inflammatory demiyeliniziruyushchy poliradikulonevropatiya forecast for life rather favorable. The lethality very low, however, an absolute recovery comes very seldom. To 90% of patients against the background of immunosupressivny therapy reach full or incomplete remission. At the same time the disease is inclined to aggravations, application of immunosupressivny therapy can be in a type of its side effects leading to numerous complications.
At hereditary polyneuropathies seldom it is possible to achieve improvement of a state as the disease slowly progresses. However patients, as a rule, adapt to the state and in most cases to the latest stages of a disease keep ability to self-service. At a diabetic polyneuropathy the forecast for life favorable on condition of timely treatment and careful control of a glycemia. Only in late stages of a disease the expressed pain syndrome is capable to worsen quality of life of the patient considerably.
The forecast for life at an uraemic polyneuropathy completely depends on expressiveness of a chronic renal failure. Timely carrying out a program hemodialysis or transplantation of a kidney are capable to lead to full or almost full regress of an uraemic polyneuropathy.