Reflex - the reaction of the body to external stimuli. When there is a disturbance in the work of the brain or nervous system, pathological reflexes occur, which are manifested by the pathology of motor reactions. In neurological practice, they serve as beacons for the detection of various diseases.
The concept of a pathological reflex
When the main neuron of the brain or neural pathways are damaged, pathological reflexes occur. They are manifested by new connections between external stimuli and the body's response to them, which cannot be called the norm. This means that the human body does not respond adequately to physical contact, compared to a normal person without pathologies.
Such reflexes indicate any mental or neurological diseases in humans. In children, many reflexes are considered normal (extension-plantar, grasping, sucking), while in an adult the same ones are considered pathological. At the age of up to two years, all reflexes are due to a fragile nervous system. Pathological are also conditional,and unconditioned reflexes. The former appear as an inadequate response to a stimulus, fixed in memory in the past. The latter are biologically unusual for a given age or situation.
Causes of occurrence
Pathological reflexes can be the result of brain lesions, pathologies of the central nervous system, such as:
- damage to the cerebral cortex by infections, diseases of the spinal cord, tumor;
- hypoxia - brain functions are not performed due to lack of oxygen;
- stroke - damage to the vessels of the brain;
- ICP (cerebral palsy) is a congenital pathology in which the reflexes of newborns do not fade over time, but develop;
- hypertension;
- paralysis;
- coma state;
- consequences of injuries.
Any diseases of the nervous system, damage to neural connections, diseases of the brain can cause abnormal, unhe althy reflexes.
Classification of pathological reflexes
Pathological reflexes are divided into the following groups:
- Reflexes of the upper limbs. This group includes pathological carpal reflexes, an unhe althy response to external stimuli of the upper extremities. May be manifested by involuntary grasping and holding an object. They occur when the skin of the palms at the base of the fingers is irritated.
- Reflexes of the lower extremities. These include abnormal foot reflexes, reactions to tappinghammer in the form of flexion or extension of the phalanges of the toes, flexion of the foot.
- Reflexes of the mouth muscles - pathological contraction of the muscles of the face.
Foot reflexes
Extension reflexes of the foot are an early manifestation of damage to the nervous system. The pathological Babinski reflex is most often tested in neurology. It is a sign of upper motor neuron syndrome. It belongs to the group of reflexes of the lower extremities. It manifests itself as follows: a dashed movement along the outer edge of the foot leads to the extension of the big toe. May be accompanied by a fanning of all toes. In the absence of pathology, such irritation of the foot leads to involuntary flexion of the big toe or all toes. Movements should be light, not causing pain. The reason for the formation of the Babinski reflex is the slow conduction of irritation through the motor channels and the violation of excitation of the segments of the spinal cord. In children under one and a half years old, the manifestation of the Babinski reflex is considered the norm, then with the formation of a gait and an upright position of the body, it should disappear.
A similar effect may occur with other effects on receptors:
- Oppenheim reflex - extension of the finger occurs when pressed and moved from top to bottom with the thumb in the tibia;
- Gordon's reflex - when contracting the calf muscle;
- Schaeffer reflex - with compression of the Achilles tendon.
Pathological foot flexor reflexes:
- Rossolimo reflex - when exposed to jerky blows of the hammer or fingertips on the inner surface of the phalanges, the II-V toes of the foot are quickly flexed;
- Bekhterev's reflex - the same reaction occurs when lightly tapping on the outer surface of the foot in the area of the metatarsal bones;
- Zhukovsky's reflex - manifests itself when hitting the center of the foot, at the base of the fingers.
Reflexes of oral automatism
Oral automatism is a reaction of the muscles of the mouth to an irritant, manifested by their involuntary movement. This kind of pathological reflexes are observed in the following manifestations:
- Nasolabial reflex, occurs when tapping at the base of the nose with a hammer, manifested by stretching the lips. The same effect can occur when approaching the mouth (distance-oral reflex) or with light blows to the lower or upper lip - the oral reflex.
- Palmar-chin reflex, or Marinescu-Radovic reflex. Stroke movements in the area of the thumb from the side of the palm cause a reaction of the facial muscles and set the chin in motion.
Such reactions are considered normal only for infants, their presence in adults is a pathology.
Sykinesis and defensive reflexes
Synkinesis are reflexes characterized by paired movement of limbs. Pathological reflexes of this kind include:
- global synkinesis (when bendingarms unbend leg or vice versa);
- imitative: involuntary repetition of movements of an unhe althy (paralyzed) limb after the movements of a he althy one;
- coordination: spontaneous movements of an unhe althy limb.
Synkinesis automatically occurs with active movements. For example, when moving a he althy arm or leg in a paralyzed limb, spontaneous muscle contraction occurs, a bending movement of the arm occurs, and the leg is extended.
Protective reflexes occur when a paralyzed limb is irritated and are manifested by its involuntary movement. An irritant can be, for example, a needle prick. Such reactions are also called spinal automatisms. Protective reflexes include the symptom of Marie-Foy-Bekhtereva - flexion of the toes leads to involuntary flexion of the leg at the knee and hip joint.
Tonic reflexes
Normally, tonic reflexes appear in children from birth to three months. Their continued manifestation even in the fifth month of life may indicate the defeat of the child with cerebral palsy. In children with cerebral palsy, congenital motor automatisms do not fade away, but continue to develop. These include pathological tonic reflexes:
- Labyrinth tonic reflex. It is checked in two positions - on the back and on the stomach - and manifests itself depending on the location of the child's head in space. In children with cerebral palsy, it is expressed in increasedextensor muscle tone when lying on the back and flexor muscles when the child is lying on the stomach.
- Symmetrical cervical tonic reflex. With cerebral palsy, it is manifested by the influence of head movements on the muscle tone of the limbs.
- Asymmetric cervical tonic reflex. It is manifested by an increase in the tone of the muscles of the limbs when the head is turned to the side. On the side where the face is turned, the extensor muscles are activated, and on the side of the back of the head, the flexors.
In cerebral palsy, a combination of tonic reflexes is possible, which reflects the severity of the disease.
Tendon reflexes
Tendon reflexes are normally caused by hammer blows on the tendon. They are divided into several types:
- Biceps tendon reflex. In response to a blow with a hammer on it, the arm bends at the elbow joint.
- Triceps tendon reflex. The arm is bent at the elbow joint, extension occurs upon impact.
- Knee reflex. The blow falls on the quadriceps femoris muscle, under the kneecap. The result is leg extension at the knee joint.
Pathological tendon reflexes are manifested in the absence of response to hammer blows. May occur with paralysis, coma, spinal cord injury.
Is treatment possible?
Pathological reflexes in neurology are not treated by themselves, since this is not a separate disease, but just a symptom of some mental disorder. They indicate problems in the functioning of the brain and nervous system. Therefore, it is necessary, first of all, to look for the cause of their appearance. Only afterdiagnosis by a doctor, we can talk about a specific treatment, because it is necessary to treat the cause itself, and not its manifestations. Pathological reflexes can only help in determining the disease and its severity.
