The electric diagnostics

The electric diagnostics is a method of research of functional state of nerves and muscles with the help of irritation their electric current. In assessing the state of neuro-muscular apparatus the main role plays the character of muscle contraction. If irritation healthy muscles are marked living, fast cuts and degenerative muscle responds slow, sluggish reduction. Quantification of the changes is to compare thresholds elektrovozoremontnij on healthy and affected parties. For this purpose use both AC and DC; electrodes placed on motor point - a place of occurrence of the nerve to the muscle.
Electroodontodiagnosis is a method of investigation of the functional state of a sensitive nerve of the tooth with the help of irritation electric current is used in dentistry for determining the degree of pathological changes pulp or periodontitis.
The study of elektrovozoremontnij allows not only to make the diagnosis, but also to monitor the dynamics of the pathological process, to monitor the effectiveness of therapy, determine prognosis.

The electric diagnostics is a method of research reactions of the nerves and muscles to stimulation by an electric current. At pathology anxiety tissue can vary widely: from rising to no. The study excitability allows you to determine the state of the tissue and thereby clarify the diagnosis. This causes wide application of electric diagnostics in clinic.
The degree of excitability judged by the minimum (threshold) the strength of the stimulus that can cause arousal. The minimum intensity irritation, beyond which the immense increase in the duration of its action is not effective, is called reality. The minimum time in which the intensity equal to LeoBase, causes excitation is called a useful time.

Fig. 1. The graphic image of the current received from the induction coil.

For research irritability of nerves and muscles used several forms of power. Classical electric diagnostics, i.e. a method that was developed by its founders, was reduced to the study of excitation by means of the so-called faradic and DC. To obtain the faradic current applied induction coil, which in the analyzed neuromuscular apparatus was sent 20-30 pulses per 1 sec. (the graphics of this current is presented in Fig. 1). Irritation followed one another with such frequency that the muscle was the state of tetanus. Affection of peripheral motor neuron response to irritation shock of this form may not occur: the pulses can be sufficient to excite the diseased tissue. No reaction to this current does not mean a complete lack of excitability, it can only bear witness of it falls. Recently, instead of the faradic current use so-called titaninium shock, little different in form and physiological effect from faradic. A more complete picture of the state of neuro-muscular apparatus can be obtained on the basis of the study of excitability of DC, with the help of which you can find not only quantitative, but also qualitative change of elektrovozoremontnij. On the last judged by the polar equation and the nature of the muscle contraction. Numerous studies have found that the current strength necessary for the emergence of excitation of nerve or muscle, increasing as follows: GLC>fuel>APC>cattle ( reduction occurs at a lower current than antisemitically; antisemitically - before antiastenicescoe; antiastenicescoe - at a lower current than categorytree). Affection of nervous-muscular apparatus may come a perversion of the polar formula (ACS>GLC) and others, whose causes are not fully understood. Undoubtedly only one: in the basis of it, along with major changes in neuro-muscular apparatus are often purely physical factors - the electrical conductivity of the tissue adjacent to the investigated site nerve or muscle, resulting in the anode causes excitation at a lower current than the cathode (L. R. Rubin). That is why the diagnostic value of perversion polar formula is small. Exceptionally important role in the assessment of neuromuscular apparatus plays the character of muscle contraction. OK irritation muscle is responsible alive, lightning reduction, with the defeat of motor nerve in the relevant muscles occur degenerative processes that are manifested sluggish, worm-like contractions.
The study of elektrovozoremontnij using the classical method of electric diagnostics started with teensyoung current. Defining a threshold of excitability of the first healthy, and then on the affected side, establish the presence or absence of quantitative changes. Then move to the effect of direct current, which allows to determine the quantitative and qualitative changes of elektrovozoremontnij.
For a partial response rebirth characterized by the following picture changes elektrovozoremontnij:

Current Etansarii Permanent
Nerve The decrease in excitability The decrease in excitability
Muscle The decrease in excitability Sluggish reduction, perversion polar formulas (not always)

With the full reaction of degeneration is characterized by the following data:

Current Etansarii Permanent
Nerve There has been no reaction There has been no reaction
Muscle There has been no reaction Sluggish, worm reduction, perversion polar formulas (not always).

No reaction muscles are very strong, hard-portable currents indicates the death of nerve and muscle.
Change elektrovozoremontnij not go hand in hand with other clinical manifestations of disorders of the peripheral motor neuron. In the first days sometimes there is even increased excitability. In 4-6 days begins a gradual reduction of elektrovozoremontnij nerve (and sometimes muscle), defined as titaninium and direct current. After 15-20 days, the nervous reaction to both current disappears, the same muscles react only to the irritation of DC, with the threshold of them may even be reduced, although reductions are already sluggish nature. By this time, there may be a perversion of the polar formulas and displacement motor point muscles towards its distal end. This lasts quite long (7-8 months and more). Outcome it may be the case nerve regeneration recovery excitability (and restore options ahead of the emergence of a response to irritation current) or its complete extinction (loss of muscle).
Not all States neuromuscular apparatus classical electric diagnostics allows you to accurately investigate anxiety. When advanced lesions of the peripheral motor neuron (full response rebirth) faradic current (pulse frequency - 20-30 per 1 sec.) does not cause tetanus. However, in these cases, you can call tetanicescie muscle contraction: it is only necessary to find the appropriate frequency pulses. Deviation to one side or the other from the found optimum frequency stimulation leads (even with significant increase of force of a current) to the weakening of tetanus. The better the condition of nervous-muscular apparatus, the more optimal frequency. Thus, the frequency of pulses that can cause tetanus, you can judge the state of the muscles, and thus about the dynamics of the pathological process.
The study excitability using direct current is reduced to the single parcel of rectangular pulses, which are characterized by very steep arousal, which allows the threshold current to minimize. But a heavy defeat peripheral motor neuron use of such pulses is impractical because of the threshold current in these cases is achieved earlier with a more gentle, gradual increase of the pulse. In a number of observations established that for denervated muscles pulses with gradual increase of force of a current "fizjologiczne" pulses with fast increasing current. So for the study of these muscles is to use exponentially growing current pulses. Thus, the study pulses exponential form and define the optimal frequency that can cause tetanus, serve as a significant addition to the classical electric diagnostics.

the active electrode
Fig. 2. The active electrode with a circuit breaker.
motor point of nerves and muscles of the head and neck
Fig. 3. Motor point of nerves and muscles of the head and neck: 1 - m. corrugator supercillii; 2 - m. orbicularis oculi; 3 - m. nasalis (pars transversa); 4 - m. orbicularis oris; 5 - m. depressor labii inf.; 6 - m. mentalis; 7 - point Erba (plexus brachialis); 8 - mm. scaleni; 9 - platysma; 10 - m. sternocleidoma stоideus; 11 - n. facialis (ramus inferior); 12 - n. facialis (trunk); 13 - m. nasalis (pars alaris); 14 - n. facialis (ramus medius); 15 - n. facialis (ramus superior); 16 - m. temporalis; 17 - m. moreover.

Method of investigation of elektrovozoremontnij motor nerves and muscles is the following. Lead plate with the thickness of 0.4 - 0.6 mm and an area of 300 - 400 cm2 (passive electrode) connect the cord with one of the poles of the power source. Under the plate is placed dampened with warm water hydrophilic strip of 8-10 layers of white flannel or tales (the size of a few more plates to avoid burns upon contact of metal with the skin). The passive electrode with gasket strengthen bandage on the sternum area or lower back. The other electrode (active) is a copper round plate with a diameter of 1 to 1.5 cm, soldered to the metal bar fixed in isolating handle with tripped (figure 2), which allows to close and razmyat chain patient. The active electrode connected to the other pole of the power source and placed on a motor point of the investigated (nerve muscle). Existing schemes motor points of all available research nerves and muscles (Fig. 3-6) give only a General idea of their topography; only experience can help you quickly identify the required propulsion point. Having found it, define their threshold, beginning with very weak irritation and gradually increasing. Any irritation effect on the functional state of the tissue. Thus, the intensity of irritation more, the sharper impact of its action. To avoid errors caused by the action of the previous irritation, further irritation should be applied in 1-2 seconds, while obviously pathological conditions - in 5-10 seconds. Be aware that the study of excitability may prevent excessive warming or cooling of the relevant parts of the body, and fatigue muscles. The patient should be given a position in which analyzed the muscles and their antagonists are in the most relaxed position. The study produced in good light to catch the minimum muscle contraction. If you cannot cause a reaction with motor point, the active electrode is gradually shifting towards the end of the muscles to determine shifted whether musculoskeletal point. If this cannot cause loss pass to the study "uaktywni" method where the ends of the muscle impose two small electrode - the so-called uaktywni electrode (Fig. 7).

motor point nerves and muscles of the hands Fig. 4. Motor point nerves and muscles of the hands:
a - front surface: 1 - m. coracobrachialis; 2 - n. medianus; 3 - m. biceps brachii; 4 - n. medianus; 5 - m. pronator teres; 6 - m. flexor carpi ulnaris; 7 - m. palmaris longus; 8 - m. flexor digitorum superficialis; 9 - n. ulnaris; 10 - n. medianus; 11 - m. abductor digiti minimi; 12 - m. flexor digiti minimi brevis; 13 - mm. lumbricales; 14 - m. adductor pollicis; 15 - m. flexor pollicis brevis; 16 - m. abductor pollicis brevis; 17 - m. flexor pollicis longus; 18 - m. flexor digitorum profundus; 19 - m. palmaris longus; 20 - m. flexor carpi radialis; 21 - m. brachialis; 22 - m. triceps brachii; 23 - m. deltoideus.
b - rear surface: 1 - m. deltoideus; 2 - m. triceps (caput lat.); 3 - n. radialis; 4 - m. supinator; 5 - m. extensor carpi radialis longus; in - m. extensor carpi radialis brevis; 7 - m. extensor digitorum; 8 - m. extensor digiti minimi; 9 - m. extensor pollicis brevis; 10 - m. extensor pollicis longus; 11 - mm. interossei dorsales; 12 - m. extensor indicis; 13 - m. flexor carpi ulnaris; 14 - m. extensor carpi ulnaris; 15 - n. ulnaris; 16 - m. triceps (caput mediale); 17 - m. triceps (caput longum).
motor point trunk muscles and nerves of the feet
Fig. 5. Motor point trunk muscles and nerves of the legs:
a - front surface: 1 - m. sternocleidomastoideus; 2 - m. omohyoideus; 3 - m. deltoideus; 4 - m. pectoralis major (pars sternocostalis); 5 - m. obliquus abdominis ext.; 6 - n. femoralis; 7 - m. rectus abdominis; 8 - m. pectoralis major (pars clavicularis); 9 - m. trapezius; 10 - point Erba (plexus brachialis); 11 - platysma.
b - rear surface: 1 - m. supraspinatus; 2 - m. deltoideus; 3 - m. infraspinatus; 4 - m. rhomboideus major; 5 - m. latissimus dorsi; 6 - m. obliquus abdominis ext.; 7 - m. gluteus minimus; 8 - m. gluteus maximus; 9 - n. ischiadicus; 10 - m. latissimus dorsi; 11 - m. trapezius; 12 - m. rhomboideus minor; 13 - m. trapezius.
motor point nerves and muscles of the legs Fig. 6. Motor point nerves and muscles of the legs:
a - front surface: 1 - n. femoralis; 2 - m. sartorius; 3 - m. pectineus; 4 - m. adductor longus; 5 - m. adductor magnus; e - m. quadriceps femoris; 7 - m. vastus med.; 8 - m. tibialis ant.: 9 - m. extensor hallucis longus; 10 - mm. interossei dorsales; 11 - m. extensor digitorum brevis; 12 - m. peroneus brevis; 13 - m. extensor digitorum longus; 14 - m. peroneus longus; 15 - m. soleus; 16 - n. peroneus communis; 17 - m. vastus lat.; 18 - m. tensor fasciae latae.
b - rear surface: 1 - m. gluteus min; 2 - m. tensor fasciae latae; 3 - m. biceps femoris (caput longum); 4 - m. biceps femoris (caput breve); 5 - n. tibialis; s - m. the gastrocnemius muscle (caput lat.); 7 - m. soleus; 8 - m. peroneus longus; 9 - m. peroneus brevis; 10 - m. flexor hallucis longus; 11 - m. extensor digitorum brevis; 12 - m. abductor digiti minimi; 13 - m. tibialis; 14 - m. flexor digitorum longus; 15 - m. the gastrocnemius muscle (caput mediale); 16 - m. semitendinosus; 17 - m. semimembranosus; 18 - n. ischiadicus; 19 - m. gluteus maximus.
uaktywni electrode
Fig. 7. "Uaktywni" electrode.

Explore the mimic and chewing muscles more comfortable in a sitting position of the patient. Chewing and temporal muscle tested at slightly ajar mouth. For the study of muscles of the shoulder girdle the patient is seated, hands down. For the study of muscles of the shoulder, bent at the elbow joint hand slightly away from the body (Fig. 8). In the study of the muscles of the upper half of the body, the patient can sit or lie down; the muscles of the lower half of the body, as well as the nerves and muscles of lower limbs easier to explore in the supine position of the patient (Fig. 9). For research peroneal nerve patient is placed on his back, and for the tibial nerve - on his stomach.
When unilateral lesions of nervous-muscular apparatus first determine the threshold current is necessary for the purpose of the nerve or muscle on the healthy side, and maps with the threshold power at the patient's side. To judge availability of quantitative changes excitability is possible only in case of severe difference in thresholds for the sick and the healthy side. With bilateral lesions of quantitative changes can speak only in cases when either very weak currents cause severe reduction or, on the contrary, strong currents cause weak contractions.

Rice, 8. The most comfortable hand position (1-2) to study elektrovozoremontnij.

Fig. 9. The most convenient position of the feet (1-3) to study elektrovozoremontnij.

Quantitative changes in excitability in the form of increase may occur in the initial period, diseases of the peripheral motor neuron. Usually an increase in the excitability observed tetanii. The decrease in excitability is sometimes found and in the absence of disorders of the peripheral motor neuron, namely when pronounced secondary muscle atrophy. Characteristic lesions of the Central motor neuron is the absence of any qualitative changes excitability. Quantitative changes are considered to be non-specific. In the early stages of the disease may sometimes find the rise, and in late - some lowering anxiety.
Particularly noteworthy are changes anxiety in infants and myotonia. In infants the first current pulses at first cause the normal reaction, then reduce become weaker and finally completely disappear (myasthenic reaction). After relaxing the excitability of muscles is restored.
Myotonica reaction is that the contraction of the muscles, caused by electric irritation (especially titaninium shock), kept for some time after shutdown current (5-20 seconds). Elektrovozoremontnij nerves normal. This kind of reaction is observed when the disease.