Research of reflexes

In clinical practice, deep (for stretching muscles) and superficial (skin, from mucous membranes) reflexes are investigated.

A deep (miotatic) reflex is an involuntary contraction of the muscle in response to stimulation of the muscle spindle receptors contained in it, which in turn is due to passive stretching of the muscle. Such stretching in clinical practice is usually achieved by a short, abrupt impact of the neurological malleus over the muscle tendon.

The characteristics of deep reflexes reflect the integrity of the entire reflex arc (the state of the sensory and motor fibers of the peripheral nerve, the posterior and anterior roots of the spinal nerves, the corresponding segments of the spinal cord), and the ratio of inhibitory and activating nassegmental influences. A deep reflex is caused by an easy rapid blow to the tendon of a relaxed and slightly stretched muscle. When striking, the hand should perform free oscillatory movement in the wrist joint, the handle of the neurological hammer is not held tightly, so that the hammer can perform some additional vibrational motion around the fixation point. Avoid "puffing" movements with your hand. The patient should be in a fairly relaxed state and do not make efforts to maintain balance; its limbs should be located symmetrically. If the patient strains the muscle, the reflex decreases or disappears altogether. Therefore, if the reflex is hard to work out, the patient's attention is distracted from the area under study: for example (when examining the reflexes from the legs), ask to tighten the teeth tightly or to couple the fingers of both hands and pull the wrists to the sides with force. (Receive Endressik).

The severity of deep reflexes is sometimes assessed on a 4-point scale: 4 points - a sharply increased reflex; 3 points - lively, but within normal limits; 2 points - normal expression; 1 point - reduced; 0 points - absent. The expression of reflexes in healthy individuals can vary considerably.

Normally, the reflexes on the legs are usually more pronounced and are easier to produce than on the hands. A slight bilateral revitalization of deep reflexes does not always indicate a defeat of the pyramidal system; it can be observed in a number of healthy individuals with increased nervous excitability of the nervous system. A sharp increase in deep reflexes, often combined with spasticity, indicates the defeat of the pyramidal system. Decrease or absence of reflexes should alarm: whether there is at the patient a neuropathy or a polyneuropathy? Two-sided hyporeflexia and hyperreflexia have less diagnostic significance in comparison with the asymmetry of reflexes, which usually indicates the presence of the disease.

Investigation of deep reflexes

• Reflex from the tendon of the biceps arm muscle (biceps reflex, flexion-elbow reflex) closes at the level of C ₅ -C ₆. The doctor puts the patient's arm slightly bent at the elbow joint on his forearm, grasps the elbow joint with four fingers from the bottom, and the thumb has the relaxed upper limb of the patient is on the abdomen, the elbow joint rests on the bed from above on the tendon of the biceps muscle. Apply a short and quick hammer blow to the thumb of your hand. Evaluate the contraction of the biceps arm and the degree of flexion of the patient's arm.
• The reflex from the tendon of the triceps muscle of the shoulder (triceps reflex, extensor-elbow reflex) is closed at the level of C ₇ -C ₈. The doctor, standing in front of the patient, supports his half-bent arm beyond the elbow and forearm area (or supports the withdrawn shoulder of the patient directly above the elbow joint, while the forearm freely hangs downward) and strikes with a hammer on the tendon of the triceps brachium by 1-1.5 cm above the ulnar process of the ulna. Assess the degree of reflex extension of the arm in the elbow joint.
• The carious-ray (carporadial) reflex is closed at the level of C ₅ -C ₈. The doctor freely places the patient's hand on his wrist so that it is bent at the elbow joint at an angle of approximately 100 °, and the forearm is in a position intermediate between pronation and supination. Hammer blows are applied along the styloid process of the radius, evaluating the flexion in the elbow joint and pronation of the forearm. The patient lying on the back of the patient carries out the same procedure, but the hands of his bent at the elbow joints of the hands are on the abdomen. If the reflex is examined in the patient's standing position, the hand of his arm, bent at the elbow joint, is held in the necessary (semipermanent) position by the doctor's arm. When examining deep reflexes on the arm, special attention should be paid to the zone of propagation of the reflex reaction. For example, when eliciting a flexor-elbow or carapordial reflex, flexion of the fingers of the hand may occur, which indicates the defeat of the central motoneuron. Sometimes there is an inversion (perversion) of the reflex: for example, when the biceps reflex is called, there is a contraction of the triceps brachium rather than the biceps muscle. Such a violation is explained by the spread of excitation to neighboring segments of the spinal cord in the presence of a damaged anterior root, which innervates the biceps brachii muscle of the shoulder.
• The knee reflex closes at the level of L ₃ -L ₄. When checking this reflex, the legs lying on the back of the patient should be in a semi-bent position, and the feet should touch the couch. To the patient was able to relax the muscles of the thigh, the doctor brings his hands to his knees, supporting them. If the relaxation is not enough, ask the patient to press down the couch with force or use the reception of Endrasik. Hammer blows are applied to the tendon of the quadriceps femoris below the kneecap. Evaluate the degree of extension in the knee joint, noting whether the reflex response does not extend to the adductor muscles of the hip. When examining a reflex in a sitting patient, it is necessary that his heels freely contact the floor, and the legs should be bent at an obtuse angle in the knee joints. One hand grasps the distal thigh of the patient, the second - they strike with a hammer on the tendon of the quadriceps muscle of the thigh. With this variant of the research, the reflex contraction of the muscle can not only be seen, but also felt by the hand located on the thigh. The knee jerk can also be examined when the patient sits in a "foot-to-leg" position or when sitting on a high chair so that his shins dangle freely without touching the floor. These variants allow observing a poorly dying, "pendulum" knee reflex (with cerebellar pathology) or a Gordon reflex (in the case of Huntington's chorea or small chorea), that after striking the tendon of the quadriceps muscle of the thigh, the leg is unbent and stays in it for some time position.

• Achilles reflex is closed at the level of S ₁ -S ₂. The essence of this reflex is that the patient lying on the back has one leg wrapped around the foot of the leg being examined, the leg is bent in the hip and knee joint and simultaneously the leg is unbent. The second hand is struck with a hammer on the Achilles tendon. To study the reflex in the position of the patient lying on his stomach, his leg is bent at a right angle in the knee and ankle joints. With one hand, hold the foot, slightly unbending it in the ankle (rear bending), and the other - apply a light blow to the Achilles tendon. You can also ask the patient to kneel on the couch in such a way that the feet freely hang from her edge; hammer blows are applied to the Achilles tendon, assessing the degree of extension in the ankle joint.

When examining deep reflexes from the feet simultaneously check whether there are clones of the foot or knee cap. Clonus - repeated involuntary rhythmic contraction of the muscle, caused by rapid passive stretching of the muscle itself or its tendon. The clonus occurs when the central motoneuron (pyramidal system) is damaged due to the loss of supraspinal inhibitory influences. The increase in deep reflexes on the lower limb is often combined with the clone of the foot and knee cap. To elicit a clone of the foot in a patient lying on his back, the leg in the hip and knee joints is bent, holding it with one hand for the lower third of the thigh, and the other hand grasping the foot. After maximum plantar flexion, the foot is suddenly unbent at the ankle joint, and then continue to exert pressure on it, holding it in this position. In a patient with spastic paresis of muscles, this test often causes a clone of the foot - rhythmic flexion and extension of the foot due to repeated contraction of the gastrocnemius muscle arising in response to the stretching of the Achilles tendon. Several oscillatory movements of the foot are possible in healthy individuals, but a persistent clone (five or more flexion-extensor movements) indicates a pathology. A sample to identify the clone of the patella is carried out in the patient lying on his back with his legs straight. Having grasped the upper edge of the patella by the thumb and forefinger, move it upward along the skin, and then sharply move it down, keeping it in the extreme position. In patients with severe spasticity, such a test causes rhythmic patellar oscillations up and down caused by the stretching of the tendon of the quadriceps muscle of the thigh.

Study of skin (surface) reflexes

• Abdominal skin reflexes cause dashed irritation of the abdominal skin on both sides towards the midline. To induce the upper abdominal reflex, the dashed stimulation is applied directly below the edge arches (the arc of the reflex is closed at the level of T ₇ -T ₈ ). To elicit an average abdominal reflex (T ₉ -T ₁₀ ), the stimulation is applied horizontally at the level of the navel, the lower abdominal (T ₁₁ -T ₁₂ ) - above the puarthite ligament. Irritation is caused by a blunt wooden stick. The response is the contraction of the abdominal muscles. With repeated irritation, the abdominal reflexes are reduced ("exhausted"). Abdominal reflexes are often absent in obesity, in elderly people, in multiparous women, in patients who have undergone abdominal surgery. The asymmetry of abdominal reflexes may have a diagnostic value. One-sided loss of them can indicate ipsilateral spinal cord injury (break of the pyramidal tract in the lateral cords of the spinal cord above the level of T ₆ -T ₈ ) or contralateral lesion of the brain involving the motor zones of the cortex of the cerebral hemispheres or pyramidal system at the level of the subcortical formations or brainstem .
• Plantar reflex (closes at the level of L ₅ -S ₂ ) causes a dashed stimulation of the outer edge of the sole from the heel to the little finger, and then in the transverse direction to the base of the first finger. Skin irritation should be sufficient in strength and last about 1 second. Normally in adults and children older than 1.5-2 years, in response to irritation, plantar flexion of the toes occurs.
• Cremaster reflex (closes at the level of L ₁ -L ₂ ) causes dashed irritation of the skin of the inner surface of the thigh, directed from the bottom up. Normally, there is a contraction of the muscle that lifts the testicle.
• The anal reflex (closes at the level of S ₄ -S ₅ ) is caused by skin irritation near the anus. The patient is asked to lie on his side and bend his knees and lightly touch a thin wooden stick edge of the anus. The response is normally a reduction in the external sphincter of the anus, and sometimes the gluteus muscle.

Pathological reflexes appear when the central motoneuron (pyramidal system) is damaged. Reflexes caused from the extremities are subdivided into extensor (extensor) and flexor (flexor). To the pathological (in adults) also include reflexes of oral automatism.

Pathological extensor reflexes

• The Babinsky reflex (extensor plantar reflex) is the most important symptom in the diagnostic plan, indicating the defeat of the central motor neuron. It is manifested by an abnormal response to the dashed stimulation of the outer edge of the sole: instead of the foot flexing of the toes observed in the normal way, a slow tonic extension of the first finger and a slight fan-shaped divergence of the remaining fingers occur. At the same time, sometimes a slight bending of the leg in the knee and hip joints is observed. It should be borne in mind that if Babinsky's symptom is poorly expressed, repeated attempts to induce it often lead only to a further extinction of the reflex, so in doubtful cases it is necessary to wait a few minutes before again attempting to reveal the extensor plantar reflex. In children under 2-2.5 years, the extensor plantar reflex is not pathological, but at an older age its presence always indicates a pathology. It is important to remember that the absence of Babinsky's reflex does not exclude the defeat of the central motor neuron. For example, it may be absent in a patient with central paresis with a pronounced weakness of the leg muscles (the thumb can not unbend) or with the concomitant interruption of the afferent part of the corresponding reflex arc. In such patients, the dashed stimulation of the edge of the sole does not elicit any response - neither the normal plantar reflex nor the symptom of Babinsky.
• Oppenheim's reflex : the patient lying on the back is held by pressing the thumb pad on the front surface of the tibia (along the inner edge of the tibia) in a direction from the top to the bottom, from the knee to the ankle. The pathological response is the extension of the first finger of the patient's foot.
• Reflex Gordon : the hands compress the calf muscle of the patient. A pathological reflex is the extension of the first finger or all toes of the foot.
• Cheddock Reflex : cause a dashed skin irritation of the lateral edge of the foot immediately below the external ankle in the direction from the heel to the rear of the foot. The pathological response is the extension of the first toe.
• Reflex Scheffer : squeeze the patient's Achilles tendon with fingers. The pathological reflex is the extension of the first toe.

Pathological flexion reflexes

• Upper reflex Rossolimo (reflex Tromner). The patient relaxes his hand and brush. The doctor grasps the hand of the patient with the hand so that her fingers hang freely, and with a quick, jerky movement, it hits the palm surface of the tips of the half-bent fingers of the patient in the direction from the palm. In a pathological reaction, the patient flexes the distal phalanx of the thumb and excessively bends the distal phalangeal fingers of the hand. A qualitative upgrade of the grip of the hand to investigate such a reflex was suggested by E.L. Venderyovich (reflex Rossolimo-Venderovicha): with the patient's supine brush, the impact is applied to distal phalanges slightly bent in interphalangeal joints of II-V fingers
• Reflex Rossolimo. The patient lying on the back quickly jerks his fingers on the plantar surface of the distal phalanges of the toes in a short time toward her rear. The pathological reflex manifests itself in the form of a fast plantar flexion of all toes.
• The lower reflex of Bekhterev-Mendel. The patient lying on the back is taped on the back of the foot in the region of III-IV metatarsal bones. The pathological reflex consists in the rapid plantar flexion of the II-V toes of the foot.

Reflexes of oral automatism

Some of these reflexes (for example, sucking) are observed in children of the first year of life, but as the brain matures they disappear. Their presence in adults indicates a bilateral defeat of the cortico-nuclear pathways and a decrease in the inhibitory effect of the frontal lobe.

• The proboscis reflex is caused by a tapping on the lips of the patient. They ask him to close his eyes and apply light strokes to the lips with a hammer. With a positive reflex of the patient, the circular muscle of the mouth contracts and the lips stretch forward. The same reaction that occurs in response to the finger approaching the patient's lips is referred to as the distant-oral Karchikian reflex.
• The sucking reflex is manifested by involuntary sucking or swallowing movements in response to the streaky irritation of the patient's closed lips.
• Astuzaturov's nasolabial reflex is expressed by stretching the lips forward in response to an easy tapping on the back of the nose with a hammer.
• The palm-chin reflex of Marinescu-Radovic is caused by dashed irritation (a match, the handle of the malleus) of the skin of the palm above the elevation of the thumb; it manifests itself by pulling up the skin of the chin (a reduction in the ipsilateral chin muscle - that is , mentalis). This reflex is sometimes found in the absence of any pathology.
• Glabellar reflex (from Latin glabella - nadperosye) is caused by percussion in the area of the nadripensia, that is, by an easy tapping at the point located in the middle between the inner edges of the eyebrows. Normally, in response to the first strokes, the subject blinks, then the blink stops. Pathological is the reaction in which the patient continues to close his eyelids with each stroke with a hammer. A positive glabellar reflex is observed with frontal lobe damage, as well as with some extrapyramidal disorders.

Protective reflexes occur in central paralysis and represent involuntary movements in the paralyzed limb, arising in response to intense irritation of the skin or subcutaneous tissue. An example of protective reflexes is the shorter Bekhterev-Mari-Fua reflex, consisting of bending the leg in the hip and knee joint, combined with the rear flexion of the foot in the ankle joint ("triple leg shortening") in response to strong passive plantar flexion of the toes of the paralyzed leg (or another strong irritation).

The grasping reflex is observed with a large lesion of the frontal lobe. The reflex causes the patient's palm to be unnoticeable for the patient by stroking the palm of the patient's hand at the base of the fingers (above the metacarpophalangeal joints) or by touching the hammer handle or some other object with it. Is manifested by involuntary seizure of the object, which produced skin irritation. With the extreme severity of this reflex, even touching the palm of the patient can cause a seizure movement.