WO2015126276A1 - Method for evaluating spare capacities in children with polyneuropathy - Google Patents

Abstract

The invention relates to the field of medicine, in particular to functional diagnostic methods, and is aimed at diagnostics of polyneuropathy in children. The method for evaluating spare capacities in children with polyneuropathy by applying local compression to motor axons of peripheral nerves consists in calculating the conduction velocity of an impulse along motor axons of the ulnar nerve prior to compression, then applying tourniquet compression to the forearm with a pressure which is 10-20 mmHg higher than the systolic blood pressure. At the 10^th minute from the start of compression, the impulse conduction velocity is calculated: a neural conduction reactivity equal to 4.3±1.0% indicates the exhaustion of spare capacities, whereas a reactivity of 8.4±2.1% represents the norm for relatively healthy children. The use of the method makes it possible to increase the accuracy of nerve damage assessment in children with neuropathy, enabling therapy to be carried out in good time and thereby reducing the length of patient stay in hospital.

Description

 METHOD FOR ASSESSING RESERVE OPPORTUNITIES IN CHILDREN WITH

 Polyneuropathy.

 FIELD OF TECHNOLOGY

 The invention relates to medicine, namely to functional diagnostic methods and can be widely used in clinical practice, in infectious hospitals, neurological departments for the diagnosis of polyneuropathies in children.

 BACKGROUND OF THE INVENTION

 Neuroinfectious diseases in children continue to be a serious problem of infectology due to the severity of the course and a high percentage of disabling consequences.

 Patients with diseases of the peripheral nervous system (PNS) comprise the bulk of patients in neurological hospitals. The most severe form of PNS damage is polyneuropathy in which, as a rule, motor and sensitive fibers of the peripheral nerves of the extremities suffer.

 Electroneuromyographic (ENMG) diagnostics allows you to reliably determine the state of the neuromuscular system and determine the severity of motor disorders and is manifested on ENMG by a decrease in the amplitudes of muscle responses (M-responses) and sensory potentials of nerves while maintaining the speed of the impulse (SPI) along the motor and sensory fibers of the peripheral nerves limbs. With a demyelinating lesion, decreased SPI is a diagnostic criterion for the suffering of nerve fibers of the extremities.

 The determination of the body's reserve capabilities in confronting pathological processes and mainly in the defeat of peripheral nerves (motor axons) is an urgent problem in the diagnosis of polyneuropathies.

 A wide range of normative indicators of neural conduction creates difficulties in the diagnosis of neuropathies and the assessment of the reserve capabilities of peripheral nerves.

Of great importance in assessing the functional state of the conductive properties of the peripheral nervous system are functional tests. A functional test is the load assigned to the subject to determine the functional state and capabilities of any organ, system or organism as a whole, and assess the reserve capabilities of the body.

 Known works in which to assess the reserve capabilities of the peripheral nervous system use the influence of the so-called turnstile test on the parameters of the impulse along the nerve trunk, axon excitability in normal and pathological conditions (Fullerton R.M., 1963; A. Ruskin, 1967; Abramson DI, 1971; Ruess JM, 1973; Yates, S. K., 1981; Bostock H., 1991, 1994; Mogyoros I., 1997; Mittal P., 2008).

 Known works using a turnstile test in adults on the upper limb with compression at the shoulder level are normal and in pathology (Fullerton R.M., 1963; Nielsen V.K., 1974; Mittal R., 2008), few works are devoted to studies of neural compression in adults at the level of the forearm (Ruess JM, 1973; Bostock H, 1994). However, in these works, the turnstile test is performed in adults at the shoulder level, which causes pain during compression.

 The diagnostic capabilities of the turnstile test to assess the reserve capabilities of motor axons in children have not yet been used.

There is a method for assessing the reserve capacity according to the degree of change in the SPI according to the motor axons of the median nerve with local ischemia at the shoulder level normal (Mittal P., Effect of different cuff widths on the motor nerve conduction of the median nerve: an experimental study. J. Orthop. Surg. Res. -2008. -Ns9. 3: 1), which is based on the calculation of motor SPI along the median nerve trunk in response to local ischemia created using cuffs of the sphygmomanometer at the shoulder level for 15 minutes. The pressure in the cuff of the sphygmomanometer was maintained at 20-30 mm RT. Art. higher systolic to maintain arterial occlusion. However, the authors use a turnstile test only in those examined in norm, without studying the patterns of reduction of STI in pathology, in addition, the pressure created by the cuff on the shoulder causes pain, due to the large volume of ischemic tissue. There is also a method for assessing the effect of repeated periods of local ischemia on STI according to the motor axons of the median and ulnar nerves in normal and patients with diabetes mellitus with reduced indicators of neural conductivity, subclinical signs of neuropathy (Ruess J. M., Abramson DI, Wasserman RR, Nedvar A Motor nerve conduction velocity in normal and diabetic subjects: effect of repeated periods of ischemia. Arch. Phys. Med. Rehabil. -1973. -Vol. 54. -N ° 5. -P.221-3). To assess the degree of reduction in STI, the authors used local compression at the level of the forearm using the cuff of the sphygmomanometer with a pressure higher than systolic to maintain arterial occlusion (20-30 mm Hg higher than systolic blood pressure) for 15 minutes. The disadvantages of this method are: the authors use re-compression 90 minutes after the first, which requires additional time (more than 100 minutes); use of the turnstile test only in adult subjects. These disadvantages significantly limit the use of this method as a functional test, since in the proposed embodiment, the test does not reflect the reactivity of neural conductivity in children and its implementation requires about 2 hours, which is unacceptable in routine practice.

A known method for assessing the reserve capacity of peripheral axons in uremic neuropathy is given by Krishnan A. V. Ischaemia induces paradoxical changes in axonal excitability in end-stage kidney disease. Brain. 2006 Jun; 129 (Pt 6): 1585-92. The authors use turnstile compression for 13 minutes at a pressure of 200 mm Hg at the hip level with the assessment of the excitability of motor axons of peripheral nerves by the method of "threshold tracking" of the lower extremities in patients with uremic neuropathy. The disadvantages of this method are: (1) the authors use a turnstile test only in adults; (2) the use of compression at the hip level with a pressure of 200 mmHg, which causes pain due to the large volume of ischemic tissue; (3) the use of the assessment of the excitability of motor axons by the expensive method of “threshold tracking * (hardware-software QTRAC module, copyright Institute of Neurology, London, United Kingdom); (4) use of the sample only for uremic neuropathy.

 SUMMARY OF THE INVENTION

 The invention is aimed at creating a new method for assessing the reserve capabilities of peripheral motor axons in children with polyneuropathy. The technical result achieved in this method is to ensure the accuracy of the assessment by determining the reactivity of neural conductivity in response to compression at the level of the forearm.

 The invention consists in the fact that when using local compression of the motor axons after determining the speed of the impulse along the motor axons of the ulnar nerve before compression, turnstile compression is performed on the forearm with a pressure of 10-20 mmHg. Art. higher than systolic blood pressure, then, at 10 minutes of compression, the speed of the pulse is calculated and, with reactivity of neural conduction equal to 4.3 ± 1, 0% report a depletion of reserve capacity, at 8.4 ± 2.1% - about the norm for relatively healthy children

 It has been experimentally shown that 10-minute neural ischemia at the level of the forearm in children is diagnostically informative, well tolerated for accurate assessment of reactivity of neural conductivity, both in normal and in PVPN.

 It has been established that 10-minute local nerve ischemia on the forearm in healthy children causes a regular U-shape of the dynamics of STI along motor fibers.

It is shown that the cuff pressure is 10–20 mmHg. higher systolic blood pressure provides sufficient arterial occlusion, which implements the effect of ischemia on neural conduction. An indicator of effective arterial occlusion was the absence of pulsation in the radial artery. Therefore, in order to reduce pain, it is impractical to increase the pressure in the cuff above 20 mm RT. Art. from systolic blood pressure values In order to obtain the reactivity of neural conductivity to local ischemia, it is important to determine the STI before compression, which in healthy subjects ranged from 54.7 to 70.0 (61, 0 ± 4.6) m / s, in children with PVPNP, the STI was significantly lower : from 32.9 to 51, 4 (43.5 ± 7.4) m / s (p <0.05).

 Already at 2 minutes of ischemia in healthy children, a significant decrease in STI to 59.3 ± 4.9 m / s (p <0.05) was observed, compared with the background, which increased and was maximum at 10 minutes of ischemia - 55.6 ± 3.9 m / s (p <0.05). A significant decrease in STI in children with PVPP occurred only at 10 minutes 41, 8 ± 7.5 m / s (p <0.05) (Table 1).

 Table 1

 STI indicators (m / s) in healthy and children with PVPNP before, during and after compression ischemia (Μ ± σ)

 "Significantly significant decrease in STI in relation to background values (p <0.05).

 # Significantly significant increase in STI in relation to 10 minutes of ischemia (p <0.05).

With neuropathy with initially reduced neural conduction, 51% less pronounced reactivity of neural conduction occurs than in healthy children (p <0.05). All children during the turnstile test at 1-2 minutes of ischemia in the compression area described mild discomfort and paresthesia that persisted throughout the test. Immediately after the compression was removed, paresthesias in the form of tingling appeared in the area of the hand, which disappeared 3-5 minutes after the appearance.

 The reactivity index of neural conduction for short-term ischemia served as a criterion for the reserve capacity of peripheral axons in children under normal conditions and with PVPN and amounted to an average of 8.4 ± 2.1% in healthy children at a height of ischemia (10 minutes), 4.3 ± 1, 0 % in children with PVPNP.

 Thus, the turnstile compression of the ulnar nerve on the forearm for 10 minutes can be used as a functional test for a standardized assessment of neural conductivity in children under normal and pathological conditions, without causing subjective negative feelings in the compression area.

 In the literature available to us, we did not find such methods for assessing the reserve capabilities of peripheral motor axons in children, and the combination of the proposed features, novelty, non-obviousness, effectiveness allows us to present the method as an application material for the invention.

 The method is as follows: an ENMG study was performed with an assessment of STI on motor fibers of the ulnar nerve in 28 healthy children aged 6 to 15 years (10.7 ± 2.6) and 9 children with PVPNP aged 12 to 17 years (15 , 2 ± 2.2 years) in seven time sections: before the ischemic test, at 2, 5, 10 minutes of the test and at 1, 5, 10 minutes after ischemia. Children with PVPNP had reduced indicators of neural conductivity due to a history of inflammatory polyneuropathy in periods of 6 to 720 days, an average of 1 14 days. The study was conducted in a shielded cabinet with a constant temperature control (average 24 ° C).

ENMG research was conducted on a multifunctional complex for neurophysiological studies "Neuron-Spectrum-5" manufactured by the company "Neurosoft" (Russia). Supramaximal stimulation of the ulnar nerve with rectangular electrical impulses (0.1 ms) distally C1 (wrist) and proximal C2 (elbow) relative to the compression cuff. The recording of motor responses (M-responses) and the assessment of their latencies with the assessment of STI for motor fibers was carried out with the so-called abductor digiti minimi. The active electrode was superimposed on the abdomen of the muscle, the reference electrode - on the outer surface of the metacarpophalangeal joint of the fifth finger. A ground electrode was placed between the stimulating and diverting electrodes.

 Short-term limb ischemia was created using the cuff of the sphygmomanometer. A cuff, 14 cm wide, was placed on the forearm. The skin temperature of the hypotenar was monitored using an infrared thermometer, the skin temperature was maintained above 30 ° C using a heating pad, covering the studied limb with terry cloth.

 STI indicators were studied at different time slices of the compression test, the STI was evaluated according to the standard formula:

 s

 V = T2-TI (M / C), where V is the SPI, S is the distance between the stimulating electrodes, T2 is the latent period of the M response during stimulation at the proximal point, T1 is the latent period of the M response during stimulation at the distal point. SPI is calculated before and at 10 minutes of compression. The degree of change in STI to local ischemia before compression, expressed as a percentage, characterized the reactivity of neural conductivity to short-term ischemia and averaged 8.4 ± 2.1% in healthy children, 4.3 ± 1, 0% in children with PVPP.

 The effectiveness of the proposed method is confirmed by the following examples.

 EMBODIMENTS FOR CARRYING OUT THE INVENTION.

 Example 1

Patient Ignatieva, 13 years old, medical history N ° 2506 / С2013, was admitted to the FSBI NIIDI FMBA of Russia on May 15, 2013. Diagnosis: acute flaccid paresis. She became acutely ill 2 weeks after an intestinal infection. Complaints during hospitalization for numbness of the hands and feet of the type of “socks and gloves”, muscle weakness of the upper and lower extremities, difficulty walking. In an ENMG study of 05.17.2013 (on the 10th day of illness), when the ulnar nerve was stimulated on both sides, the motor SPI was moderately reduced to 34-37 m / s, the sensory SPI was moderately reduced to 40 m / s; when the median nerve is stimulated on both sides, the SPI motor is easily reduced 51-54 m / s, the SPI sensory is easily reduced 48-50 m / s; with stimulation of the peroneal nerve on both sides of the SPI, the motor motor is moderately reduced to 38-43 m / s, the sensory SPI is moderately reduced to 33 m / s. Thus, ENMG were revealed - signs of moderate neuropathy of the sensory and motor fibers of the peripheral nerves of the upper and lower extremities of a demyelinating nature according to the polyneuropathic type of inflammatory genesis. When using turnstile compression on the forearm with a pressure of 10-20 mm RT. Art. above systolic blood pressure for 10 minutes, the reactivity of neural conduction was 3.9%. This example shows that the use of a functional test reveals, by 40% with respect to the lower limit of the norm (8.2 ± 2.1%), the reduced reserve capacity of peripheral motor axons in this patient.

 Example 2

Patient Suris, 15 years old. Medical history Ns 198 / С2013, diagnosis - Neuropathy of the left facial nerve from 1 1.01.13. On the background of hypothermia, the patient had asymmetry of the face on January 11, 2013 (weakness of the facial muscles on the left). He was hospitalized at the FSBI NIIDI FMBA of Russia with a diagnosis of "neuropathy of the left facial nerve from 01/11/13." 3 days after the appearance of weakness of the facial muscles on the left, there was a weakness of the muscles of the face on the right. Patient complaints about weakness of the facial muscles on both sides, with impaired facial movements, inability to completely close the eye on the left side, dry left eye. In an ENMG study (January 15, 2013), when the facial nerve was stimulated, the amplitude of the M response on the right was 2 mV, on the left it was reduced 0.9 mV, the latency of the M response on the right was moderately increased 9.7 ms, on the left it was increased 16.4 ms; with stimulation of the ulnar nerve SPI is easily reduced to the left of 50 m / s, to the right of 53.5 m / s; with stimulation of the median nerve on the right, SPI is normal at 55.8 m / s; with stimulation of the peroneal nerve on the left, STI is easily reduced to 42.9, the tibial nerve on the right SPI is normal at 45.8 m / s. Taking into account that the SPI indices for motor axons were reduced by 5 nerves out of 7 studied and their values were at the lower limit of the norm, a turnstile test was performed on January 17, 2013 with an assessment of the reactivity of neural conduction for 10-minute local ischemia. The reactivity index of neural conductivity was 4.0%, which is typical for the polyneuropathic type. Thus, the detected ENMG signs may be due to the initial manifestations of demyelinating motor polyneuropathy (limb-cranial form) of inflammatory origin. This example shows that the use of a functional stress test in the form of a turnstile compression of the ulnar nerve on the forearm for 10 minutes allowed us to normalize the SPI and to reveal a reduced reactivity of neural conductivity, characteristic of the polyneuropathic type of damage to peripheral motor axons. This clinical example shows the economic benefits of using a 10-minute turnstile compression on the forearm, which allowed us to differentiate acute inflammatory demyelinating polyneuropathy with facial nerve damage from idiopathic facial neuropathy.

 INDUSTRIAL APPLICABILITY

 Thanks to the application of the proposed method, the accuracy of the assessment of nerve damage in children with neuropathy will increase, which will allow for timely correction of ongoing neurometabolic therapy and, accordingly, reduce the length of hospital stay in patients. This method can be widely used in clinical practice, in infectious hospitals, neurological departments to assess the reserve capabilities of peripheral motor axons in children.

Claims

 CLAIM.  A method for assessing reserve capacity in children with polyneuropathy, including the use of local compression of the motor axons of the peripheral nerves, characterized in that they calculate the speed of the impulse along the motor axons of the ulnar nerve before compression, then conduct turnstile compression on the forearm with a pressure of 10-20 mm RT. Art. above systolic blood pressure, at 10 minutes of compression, the pulse conduction is calculated and, with reactivity of neural conduction equal to 4.3 ± 1, 0% report a depletion of reserve capabilities, and at 8.4 ± 2.1% - about the norm for relatively healthy children.