In the position of the newborn on his back, when lower limbs he is relaxed, and one by one a needle prick is applied to each sole. There is simultaneous flexion of the hips, legs and feet. The reflex should be evoked equally on both sides (symmetrical). The reflex can be weakened in children born in the breech position, with hereditary and congenital neuromuscular diseases, myelodysplasia. A decrease in the reflex is often observed with leg paresis. Absence of reflex indicates damage lower sections child's spinal cord. Cross extensor reflex.
With the newborn in the supine position, we extend one leg and apply an injection in the area of the sole - in response, the other leg is extended and slightly adducted. In the absence of a reflex, a pathology of the lumbar enlargement of the spinal cord can be assumed.
Types of postural reflexes of a newborn baby:
When a newborn baby passively flexes his head, the muscle tone of the flexors in the arms and extensors in the legs increases. At the same time, when the baby straightens his head, the opposite effect appears - his arms straighten and his legs bend.
Asymmetrical and symmetrical cervical reflexes of the newborn are constantly expressed in newborns. In premature babies they are weakly expressed. Landau reflex
Give the child a “swimmer’s position” - lift the baby into the air so that his face looks down, and he will immediately raise his head, and then straighten (or even arch) his back, and also straighten his legs and arms - swallow, from 6 months to one and a half years. 1. asymmetric cervical topical Magnus-Klein reflex
These reflexes normally disappear in the first 2-3 months. So, as the unconditioned and cervical-tonic reflexes fade, the child begins to hold his head, sit, stand, walk and carry out other voluntary movements. Delay in the reverse development of tonic reflexes (over 4 months) indicates damage to the central nervous system newborn Persistent tonic reflexes prevent further development movements of the child, the formation of fine motor skills.
IN recent years they talk about the presence of a swimming reflex in a newborn, which means that the baby will flounder and will not drown if he is lowered into water. This reflex can only be tested in the presence of an instructor in the infant pool.
Problems with reflexes are the first symptoms of pathology of the central nervous system. If you are alarmed by any deviations from the norm, then do not hesitate to consult a doctor. A repeat examination must take place after the appointed time - it may vary depending on the expected nature of the pathology - from several days to a month, which will help to exclude existing suspicions or, if necessary, carry out timely treatment. Remember that the child changes every day, and the manifestation of reflexes depends on a number of conditions (fullness, fatigue and many others). It is very important to check innate reflexes over time. Timely treatment is the key to a child’s future health.
The nervous activity of the human body consists of transmitting impulses. One of the results of such transfers is reflexes. In order for a certain reflex to be performed by the body, a connection must be established from receiving the signal to the response to the stimulus.
A reflex is a reaction of a part of the body to changes in the external or internal environment as a result of influence on receptors. They can be located on the surface of the skin, generating exteroceptive reflexes, as well as on internal organs and vessels, which underlies the interorecessive or myostatic reflex.
Responses to stimuli are, by their nature, conditional and unconditional. The second group includes reflexes, the arc of which has already been formed at the time of birth. In the first, it is created under the influence of external factors.
The arc itself represents the entire path nerve impulse from the moment a person comes into contact with a stimulus until the manifestation of a response. The reflex arc contains various types neurons: receptor, effector and intercalary.
The reflex arc of the human body works like this:
The effector is actually the reacting organ itself, responding to irritation. The reflex reaction can be contractile, motor or excretory.
Polysynaptic refers to a three-neuron arc in which there is a nerve center. This arc is clearly illustrated by withdrawing the hand in response to pain.
Polysynaptic arcs have a special structure. Such a circuit necessarily passes through the brain. Depending on the location of the neurons processing the signal, there are:
If the reflex is processed in upper parts central nervous system, then neurons of the lower sections also take part in its processing. Divisions of the brainstem and spinal cord also participate in the formation of high-level reflexes.
Whatever the reflex, if the continuity of the reflex arc is disrupted, then the reflex disappears. Most often, such a rupture occurs as a result of injury or illness.
In complex reflexes to react to a stimulus, various organs are included in the links of the chain, which can change the behavior of the body and its systems.
The structure of the arc of the blink reflex is also interesting. This reflex, due to its complexity, makes it possible to study the movement of excitation along an arc, which is difficult to study in other cases. The reflex arc of this reflex begins with the activation of excitatory and inhibitory neurons simultaneously. Depending on the nature of the damage, different parts of the arc are activated. The onset of the blink reflex can be triggered by the trigeminal nerve - in response to touch, auditory - in response to a sharp sound, visual - in response to a change in light or visible danger.
The reflex has early and late components. The late component is responsible for generating the response delay. As an experiment, touch the skin of the eyelid with your finger. The eye closes with lightning speed. When the skin is touched again, the reaction is slower. After the brain processes the information received, conscious inhibition of the acquired reflex occurs. Thanks to this inhibition, for example, women very quickly learn to paint their eyelids, overcoming the natural desire of the eyelid to cover the cornea of the eye.
Other variants of polysynaptic arcs are also amenable to research, but they are often too complex and not very clear to study.
No matter what heights science has reached, the blinking and knee reflexes remain the basic reflexes for studying human reactions. Studying and measuring the speed of impulse transmission in the trigeminal and facial nerves are the basis for assessing the condition of the brain stem during various pathologies and pain.
An arc that consists of only two neurons, which are quite enough for an impulse, is called monosynaptic. A classic example of a monosynaptic arc is the knee jerk reflex. That's why detailed diagram reflex arc of the knee is located in all medical textbooks. The peculiarity of the composition of such an arc is that it does not involve the brain. The knee reflex is an unconditioned muscle reflex. In humans and other vertebrates, such muscle reflexes are responsible for survival.
It is not surprising that it is the knee reflex that is checked by a neurologist as one of the indicators of the state of the somatic nervous system. When a hammer hits a tendon, the muscle is stretched, after the irritation passes through the centripetal fiber to spinal node, signal through the motor neuron into the centrifugal fiber. Skin receptors do not take part in this experiment, however, the result is very noticeable and the strength of the reaction is easy to differentiate.
The autonomic reflex arc breaks into pieces, forming a synapse, whereas in the somatic system the path covered by the impulse from the receptor to the acting skeletal muscle is not interrupted by anything.
Blinking reflex protective R.: contraction of the orbicularis oculi muscle, e.g. when the eye is suddenly illuminated or an object appears before the eyes.
Large medical dictionary. 2000 .
Blink reflex- Blinking reaction in response to irritation by light, sound and other sensory stimuli (touching the cornea or eyelashes, waving a hand in front of the subject’s face, tapping in the area of the glabella, electrical stimulation of the supraorbital... ... Encyclopedic Dictionary in psychology and pedagogy
I Reflex (lat. reflexus turned back, reflected) is a reaction of the body that ensures the emergence, change or cessation of the functional activity of organs, tissues or the whole organism, carried out with the participation of the central nervous... ... Medical encyclopedia
BLINK REFLEX- Reflexive closure of the eyelid caused by bright light, sudden noise, wind, etc. This reflex has been extensively studied in classical conditioning studies... Dictionary in psychology
Facial nerve ... Wikipedia
Reactions to the body (reflexes) produced under certain conditions during the life of a person or animal on the basis of innate unconditioned reflexes. The term “conditioned reflexes” was introduced by I.P. Pavlov. Unlike unconditioned reflexes... ... Medical encyclopedia
- (nervi craniales; synonym cranial brain nerves) nerves leaving or entering the brain. There are 12 pairs of Ch. n., which innervate the skin, muscles, glands (lacrimal and salivary) and other organs of the head and neck, as well as a number of organs... ... Medical encyclopedia
FLASHING- BLINKING, reflex to irritation of sensitive branches trigeminal nerve(cornea, conjunctiva, skin surrounding the eye, eyelashes) or to light irritation. The centripetal arc of the reflex is t.o. either trigeminal or optic nerve.… … Great Medical Encyclopedia
K. o. called also conditioned reaction, conditioned reflex, conditioned reaction and conditioned reflex. I.P. Pavlov was the first to widely study its features. A huge amount of work carried out in Pavlov’s laboratory showed that... ... Psychological Encyclopedia
BLINK, oh, oh; imperfect 1. Same as blinking. M. eyes. Significantly to the neighbor. 2. (1st person and 2nd person not used), trans. Flicker, flickering (colloquial). A light flashes in the distance. | one-time blink, well, nope. | noun blinking, me, cf. | adj.... ... Ozhegov's Explanatory Dictionary
LASER RADIATION- forced (by laser) emission of portions of quanta by atoms of matter electromagnetic radiation. The word laser is an abbreviation formed from the initial letters English phrase Light Amplification by Stimulated Emission of Radiation (amplification... ... Russian encyclopedia of labor protection
Quantification of blink reflex response parameters includes latency and amplitude. Duration and phase are less diagnostically significant. Indicators of latency of the early response (R1) are compared with indicators of the latency of the M-response obtained with direct stimulation facial nerve(Table 41).
Table 41
Parameters of the M-response m.orbicularis oculi and blink reflex
in healthy subjects (7-67 years old)
| Parameter | M-answer | R1 | R1\M | Ipsilateral R2 | Contralateral R2 | Author |
| Latency (M±s) | 2.9±0.4 | 10.5±0.8 | 3.6±0.5 | 30.5±3.4 | 30.5±4.4 | J. Kimura, 1975 |
| «–» | 4.6±0.5 | – | – | – | – | N.Taylor, 1970 |
| «–» | 2.9±0.48 | 11.26±0.91 | – | 35.0±5.8 | 34.9±5.6 | G.B. Gruz-man, 1974 |
| Amplitude (M) | 1.21 mV | 0.38 mV | 0.53 mV | 0.49 mV | J. Kimura et al., 1969 | |
| Upper limit latency norms (absolute value) (M±3d) | 4.1 ms | 13.0 ms | 4.6 | 40.0 ms | 41.0 ms | J. Kimura, 1989 |
| Upper bound on latency asymmetry | 0.6 ms | 1.2 ms | – | – | – | J. Kimura, 1989 |
The upper limit of the latency asymmetry of ipsilateral R2 and contralateral R2 is normally 5.0 ms when stimulating the first branch of the trigeminal nerve on one side. The difference in latencies of contralateral R2 during stimulation with different sides does not normally exceed 7.0 ms. (J. Kimura, 1989). In children from 1 to 20 months of life, R2 is not registered; from 21 to 56 months, R2 is not recorded continuously. From the age of 5 years 6 months, the blink reflex does not differ from that in adults. Table 42 provides comparative data on the R1 blink reflex in children and adults (S.A. Clay, J.C. Ramseyer, 1976).
Table 42
Parameters of the R1 blink reflex in children are normal
In children, despite the shorter path of the reflex arc, high performance The latencies of the blink reflex responses, as well as the latencies of the M-response, are due to a lower speed of impulse transmission along nerve fibers compared to adults.
In pathology, changes in MiR are most often caused by damage to either the trigeminal nerve or the facial nerve. In this regard, sensory and motor types are distinguished when MiR is disrupted. In the sensory type, the latency period of all analyzed responses R1, ipsilateral R2 and contralateral R2 is increased. The motor type of MiR disorder is manifested by an increase in the latency of R1 and ipsilateral R2 and preservation of the normal latency of the contralateral R2. Foci of damage to the reflex arc can be in the pons and brain stem, therefore, 6 more types of MiR disorders are distinguished (A. Berardelli et al., 1999; J. Kimura, 1989) (Table 43).
Table 43
The main types of violation of the blink reflex when stimulated on the affected side
| No. | Designations in Fig. 124 and 128 | Localization (type) of lesion | Stimulation side | Latency | ||
| R1 | R2 ipsilateral | R2 contralateral | ||||
| Norm | N | N | N | |||
| a | Vnerve (sensory) | Amazed | | | | |
| healthy | N | N | N | |||
| b | VII nerve (motor) | Amazed | | | N | |
| healthy | N | N | | |||
| c | Basic sensory nuclei of the pons | Amazed | | N | N | |
| healthy | N | N | N | |||
| d | Unilateral spinal tracts or interneurons closing on the ipsilateral motor nuclei (uncrossed tracts) | Amazed | N | | N | |
| healthy | N | N | N | |||
| e | Unilateral spinal tracts or interneurons closing on the ipsi- and contralateral motor nuclei (crossed + uncrossed tracts) | Amazed | N | | | |
| healthy | N | N | N | |||
| f | Bilateral spinal tracts or interneurons closing on the motor nuclei on both sides | Amazed | N | | | |
| healthy | N | N | | |||
| g | Bilateral spinal interneurons and tracts that terminate on the contralateral motor nuclei (crossed tracts) | Amazed | N | N | | |
| healthy | N | N | | |||
| h | Unilateral efferent pathways (crossed and uncrossed) to motor nuclei | Amazed | N | | N | |
| healthy | N | N | |
The types of changes in latencies R1 and R2 are illustrated in the diagram (Fig. 128).
Popov A.P., Mushta I.V., Petrov S.V.
Currently, the role of electroneuromyographic (ENMG) studies is increasing in the diagnosis of diseases of the peripheral nervous system. These methods make it possible to identify pathological changes, determine the nature of the lesion, conduct topical diagnostics and evaluate the quality of the treatment. Trigeminal neuralgia is no exception. To diagnose diseases of this nerve, the blink reflex or blink reflex method is used. The blink reflex is a bioelectric analogue of the corneal reflex. The reflex arc includes fibers of the trigeminal nerve (I, II and III branches), the sensory nucleus of the trigeminal nerve, the nucleus of the facial nerve, the trunk of the facial nerve, the muscles surrounding the eyes (blinking). Also involved in the reflex arc is the system of the posterior longitudinal fasciculus, which, together with the reticular substance, plays the role of a regulatory and coordinating structure.
In general, the reflex arc of the blink reflex consists of several elements.
The monosynaptic part of the blink reflex includes a branch of the trigeminal nerve (I, II and III branches), the own nucleus of the trigeminal nerve (nucl. Sensorius principalis), located at the level of the bridge, the nucleus of the facial nerve, the trunk of the facial nerve and the orbicularis oculi muscle.
The polysynaptic part of the blink reflex consists of fibers of the trigeminal nerve, the spinal nucleus of the trigeminal nerve (nucl. Tractus spinalis), interneurons of the posterior longitudinal fasciculus, through which the impulse is transmitted to the nucleus of the facial nerve ipsilaterally and through interneurons of the opposite side to the nucleus of the facial nerve contralaterally to stimulation. Next, the impulse is applied to the orbicularis muscles of both eyes.
Thus, normally, when electrically stimulating one of the branches of the trigeminal nerve, an early component (R1) on the stimulation side and a late component (R2) on the stimulation side and on the opposite side are recorded. The first response (R1) is the result of the passage of an impulse along the monosynaptic reflex arc, the second response (R2) is the result of the implementation of a polysynaptic reflex. Thanks to the interneurons of the posterior longitudinal fasciculus, the potential is recorded on both sides.
IN this work A two-channel registration of the blink reflex was used, which made it possible to obtain a response from both sides. The study was carried out using equipment from Neurosoft: Neuro-EMG-Micro.
Active electrodes were applied to the lower eyelid at a lateral angle palpebral fissure, reference electrodes were placed on the back of the nose. The ground electrode was placed on the arm of the stimulated side. Impedance no more than 10 ohms.
Stimulation parameters: input range 50 mV, low filter frequency 5-8 Hz, high filter frequency 5000-8000 Hz, sensitivity 100 μV/div, sweep 5010 ms/div, analysis epoch 100 ms, stimulus strength 10-20 mA, stimulus duration 0, 1-0.2 ms.
Stimulation was carried out in the projection of the supraorbital, infraorbital and mental nerves (I, II and III branches of the trigeminal nerve), first on the right and then on the left side. To obtain reliable results, the procedure was repeated 3-5 times. As a result of registration, four curves are obtained: two – stimulation on the right, two – stimulation on the left.
The main purpose of studying the blink reflex is to evaluate the conduction systems of reflex arcs. The following were assessed: safety of components, latency time and duration of components on the side of stimulation and on the opposite side, symmetry of the reflex.
In our work, 40 patients with diseases of the trigeminal nerve were examined. The purpose of the work was to assess the diagnostic significance of the method for studying the blink reflex in trigeminal neuropathies. In the course of the work, the main objectives of the study were identified: to assess the detectability pathological changes, determine the nature and severity of disorders, assess the possibility of the method in the topical diagnosis of damage, identify possible dependence the severity of changes during ENMG depends on the nature and severity clinical manifestations damage to the trigeminal nerve.
To solve these problems, groups of patients were formed and the degrees of gradation of pathological changes in the study of the blink reflex were determined. The groups were formed according to the principle:
According to the degree of gradation, pathological changes in the blink reflex were divided into 3 groups:
Patients with complaints characteristic of trigeminal neuralgia were sent for the study. 32 patients (80%) were examined within a week after the onset of the disease, 8 (20%) - for a number of reasons, a month or more later, including after the start of appropriate treatment. In the first group, signs of trigeminal neuropathy of varying severity were detected in 100% of cases. In the second group (8 patients), the detection rate was 37%; in 3 patients, insignificant pronounced violations impulse conduction, no pathological changes were detected in 5 patients. Clinical manifestations of trigeminal nerve disease in this group of patients were mild or absent altogether. It is likely that these patients experienced complete or partial remission of the disease as a result of the treatment.
In terms of topical diagnostics, the identified changes were distributed as follows: neuropathy of the 1st branch – 25% (10 patients), neuropathy of the 2nd branches – 23.5% (9 patients), neuropathy of the 3rd branches – 17.5% (7 patients), bilateral trigeminal neuropathy – 23.5% (9 patients). As can be seen, in 25% of cases, minor changes in ENMG were detected, in 20% of cases, moderate changes in ENMG were detected, and in 41% of cases, pronounced changes in ENMG were detected. In 12.5% of cases, no pathology was detected. Moreover, in all patients with impaired impulse conduction along the three branches of the trigeminal nerve, signs of deep damage were detected at the level of the trigeminal nerve nucleus proper (absence of the primary component R1 during stimulation on the affected side).
Carrying out a parallel analysis of the clinical picture and the nature of changes in the study of the blink reflex, the following clinical manifestations of trigeminal neuralgia were taken into account: paroxysmal, sharp, shooting pain, provoked by washing, brushing teeth, and cold air; presence of painful facial tics; the presence of trigger points of irritation. The analysis of the above clinical manifestations in patients was carried out taking into account the severity of pain, frequency of occurrence and duration of attacks.
Of the 40 studied, 15 patients were identified (37.5%, group 1) with the most pronounced, in our opinion, clinical picture diseases. The remaining patients at the time of the study either did not complain at all (6 - 15%, group 2), or the clinical manifestations were not so pronounced, classical in nature (19 - 47.5%, group 3).
In the groups formed in this way, an analysis of the nature of electroneuromyographic changes was carried out. In group No1, 7 patients with pronounced ENMG changes were identified, 4 patients with moderately expressed ENMG changes and 5 patients with slightly pronounced changes. In group No2, 2 patients with slightly pronounced ENMG changes were identified and in 4 patients no pathological changes were detected. In group No3, 9 patients with pronounced ENMG changes were identified, 5 patients with moderately pronounced changes, 5 patients with slightly pronounced changes, and in 1 patient no pathological changes were detected. The results obtained led to the conclusion that the nature of clinical manifestations and ENMG changes in the blink reflex have the greatest correlation in the group of patients who did not have clinical manifestations of trigeminal neuralgia at the time of the study. Thus, in group No2, 2 patients with minor ENMG manifestations were identified and in 4 patients no pathological changes were detected. In groups 1 and 3, no significant differences were found, since patients with varying degrees the severity of ENMG manifestations is evenly distributed in both groups. This, in our opinion, is due to the fact that the formation of groups was based on subjective characteristics, the nature and severity of which are more closely related to the characterological characteristics and psycho-emotional state of the patients under study.
Thus, taking into account the results obtained during the work, the following conclusions can be drawn:
