It is an abnormal form of physiological deep and shallow reflex, and most of them belong to primitive brainstem and spinal cord reflex. It is mainly the manifestation of pyramidal tract damage, so it is called pathological reflex. Pathological reflex must be the damage to the central nervous system. However, infants under 1 year old are normal primitive protective reflex. Later, with the development and maturity of the nervous system, pyramidal tract and extrapyramidal system gradually formed. Later, with the development and maturity of the nervous system, the pyramidal tract and the lateral side of the pyramidal tract gradually improved to form myelin sheath, which inhibited these reflexes by the pyramidal tract. When the pyramidal tract is damaged, the inhibition is released and pathological reflex appears. Pathological reflex is mainly babinski's sign and a group of related signs. The appearance of babinski's sign in most cases indicates that the pyramidal tract has organic lesions. However, in some cases, such as hypoglycemia coma or general anesthesia, there may be a short-term pathological reflex positive. At this time, if hypertonic glucose is injected intravenously or anesthesia is relieved, this pathological sign will disappear quickly, which does not seem to indicate that the pyramidal tract has been damaged. The positive reaction of pathological reflex is produced by stimulating different parts of lower limbs. There are many methods and names, but babinski's sign is common, so even if babinski is sometimes negative, stimulating other parts to elicit positive reaction still has clinical value.
1. babinski's sign: The examinee lies on his back with his lower limbs straight. The doctor holds the ankle being examined, draws the side edge of the sole with a blunt bamboo stick, draws it from back to front to the heel of the little toe, and turns inward. The normal reaction is plantar flexion, while the positive reaction is dorsiflexion of big toe and fan-shaped expansion of rest toe.
2.Chaddock sign: the bamboo stick is drawn from the outer edge of the dorsum of the foot below the lateral ankle joint to the toe-metatarsal joint from back to front.
3. Oppenheim's sign: the doctor presses down from top to bottom along the front edge of the tibia with his thumb and forefinger.
4. Gordon's sign: press the gastrocnemius with a certain force during the examination.
5. Koda's sign: put your hand on the back of two toes outside the feet of the examinee, and suddenly relax after pressing the plantar surface.