What Is Catalepsy?

Demining the brain is one of the clinical manifestations of severe midbrain injury. Under normal circumstances, the downward facilitation and inhibitory effects of the brainstem reticular structure maintain a balanced balance, with the downward facilitation effect being slightly dominant, thereby maintaining normal muscle tension. In animal experiments, it was found that if the brain stem is cut off between the midbrain and the inferior colliculus, the animal will have de-brain rigidity, which is manifested by increased extensor tone, both upper limbs overextend and internal rotation, and lower limbs overextended The anteroposterior reclining angle of the head is a phenomenon called stiffening of the brain. When the human brain has a disease or a brain injury, a similar phenomenon to the removal of brain stiffness occurs. Mild cases can be paroxysmal, which can be induced by a slight stimulus from the outside world, while severe cases can be persistently rigid. (Gu Shanzhi) ^[1]

Go to the brain

As shown in the figure. Demindment of the brain is mainly a reflex hyperextension, which is too strong

Decreasing rigidity in the brain is an enhancement

De-brain rigidity is a critical clinical symptom. The clinical manifestations are ankylosis of limbs, posterior extension of the neck, even reversed arch, shoulder depression, upper arm adduction and internal rotation, forearm extension, excessive pronation, hip adduction, knee extension, and ankle flexion. The tongue can be extended slightly forward. Irregular breathing, often accompanied by systemic muscle twitching or muscle bundle tremors, chills, and high fever.

The appearance of de-brain rigidity suggests that the brain and midbrain,

If the patient has a de-stiffened brain, it indicates that the lesion has been seriously affected

Spinal shock

Disconnected from the high center

Cat's demining experiment

Turn the washbasin upside down, cover the basin with the mouth on the ground, and place a cotton ball with ether in it. The experimenter wears protective gloves, catches the cat in the basin, and performs anesthesia. After anesthesia, the cat was placed on its back on the operating table and fixed with a cat head holder.

Cut the skin of the neck along the midline of the neck. Separate, expose, and cut the trachea. Insert the Y-tracheal tube. Separate and ligate both common carotid arteries. An open end of a Y-type tracheal intubation was connected with an anesthesia bottle with a rubber tube to maintain anesthesia.

Turn the anesthetized cat to the prone position with the head raised and fixed. Cut the skin from the eyebrow arch to the occipital along the sagittal suture to expose the skull and temporal muscles. The part of the upper end of the temporal muscle attached to the skull was cut, and the temporal muscle was peeled from top to bottom with a scalpel to open it to enlarge the exposed surface of the skull. Then use a bone drill to drill the opening bone on one side of the parietal bone, and then use the rongeur to enlarge the opening. If there is bleeding, use bone wax to stop the bleeding. When approaching the midline of the skull and occipital bone, care should be taken not to damage the sagittal sinus and transverse sinus to avoid major bleeding.

After opening one side of the skull, use a thin and blunt shank to penetrate between the sagittal sinus and the inner wall of the skull. Carefully peel off the attachment of the sagittal sinus and the inner wall of the skull. After separating, use the rongeur to enlarge the contralateral skull. Open until the cerebral hemispheres on both sides are basically exposed.

Use a needle to pass a string in front and back of the sagittal sinus and ligate it. Open the dura mater and open the dura mater to expose the brain. At this point, the cat's head can be flexed, a blunt and thin bamboo knife inserted between the brain and cerebellum, and the occipital lobe of the two hemispheres of the brain can be slightly lifted, and the superior and inferior parts of the midbrain can be seen. Cut a knife across the superior and inferior humps, with the direction toward the bottom of the brain and pull to both sides at the same time, completely cut off this section of the brain stem. Then remove the rubber tube connected to the trachea and the anesthesia bottle, so that the cat is awake, suture the scalp wound, loosen the cat, and lie on its side on the operating table for observation.

About ten minutes or so, it can be seen that the cat's limbs are straight, the spine is stiff, the head is tilted backwards, and the tail is tilted upwards. The traditional method of derigebrate rigidity in physiology teaching experiments is to use craniotomy to cut off the brain stem between the upper and lower layers of the brain (upper and inferior colliculus) in the middle of the animal (rabbit or cat). In order to save animals, this experiment is often combined with the cerebral cortical function localization experiment, that is, two experiments are performed using the same animal. Cerebral cortical function localization experiments have been reported without craniotomy, ^[4]

Rabbit de-brain stiffness test

Its supporting experiment-to remove the rigidity of the brain, if you can not open the skull, but using extracranial puncture method will undoubtedly simplify this experimental process. The key is to determine the position of the boundary between the upper and lower stacks on the surface of the skull. We have initially determined this location by dissecting more than 20 rabbit heads, and tried the non-cranial method to remove the brain stiffness test, which has been used for teaching for many years.

Experimental Materials

Rabbit, scalpel, metal probe, injection needle, ether, etc.

Methods and results

The rabbit was lightly anesthetized with ether, the hair on the top of the head was cut off, and the front skin was cut along the midline at the top of the head to expose the skull. Draw a straight line at the intersection of the sagittal and coronal sutures to the vertex of the herringbone suture (which coincides with the sagittal suture). Divide this line into three equal parts. Right) At about 5 mm, the puncture point.

Hold the rabbit's head in one hand, and use a probe (a probe that can destroy the frog's brain and spinal cord) to drill a small hole at the puncture point on one side to pierce the skull. Then pierce the tip of the injection needle from the small hole to the gap between the mouth and the angle of the mandible to the base of the skull, and move to a wide range on both sides to break off the brain stem. Take out the needle (close the small hole with bone wax to stop bleeding) and observe. This puncture was performed on 15 rabbits, all of which showed head stiffness, tail extremities, forelegs straight (most typical of the forelimbs), and stiff spine. It is more convenient if it is performed on the basis of the cerebral cortical function localization experiment (without craniotomy).

discuss

The brain puncture point without the craniotomy method can be determined by drawing a marker line through the bone suture at the top of the rabbit's skull. The self-piercing point punctures in a certain way, which can cut off the brain stem between the upper and lower stacks. The method is simple, the success rate is high, and the rigid state is more typical. To reduce bleeding when the brainstem is severed, the animals can also be ligated on both sides of the common carotid artery and press the vertebral artery with the thumb and index finger at the posterior edge of the first cervical transverse process. If postoperative brain stiffness does not occur, the plane that cuts off the brainstem can be moved back and broken again as appropriate. But don't go too far so as not to hurt the medulla.

"Experimental method for removing stiff brain without craniotomy (2)". Puncture point: Draw a straight line from the intersection of the coronal and sagittal sutures to the vertex of the herringbone suture, where the first 2/3 and the rear 1/3 of this line intersect. Method (2) The puncture site is thick in bone, has a lot of bleeding, and the animal survives for a short time. The puncture site of this method is thin (easy to puncture), there is less bleeding, and the animal survives for a long time, which can be observed for a long time. Both methods have the advantages of higher success rate and simplicity, but this method is more practical and should be preferred.

Do not open the skull to destroy the cerebellum on one side of the rabbit. The puncture point is also determined with the help of the skull bone mark, and the extracranial puncture method is completed. According to relevant reports, after repeated practice, experiments on the central nervous system of physiology textbooks in secondary health schools can be completed on the same animal without craniotomy. Sequence: Functional localization of the cerebral cortex motor area Observation of cerebellar animals Removal of rigidity of the brain. The subjects were limited to rabbits, and lightly anesthetized with ether. Save time, save trouble, save animals, and the effect remains undiminished. Cerebellum removal, using rabbits as experimental subjects is better than mice or toads, and more cerebellar removal symptoms may occur. After the cerebellar hemisphere on one side of the rabbit was damaged by extracranial puncture, the brain stem was still severed after the brainstem was broken between the upper and lower layers of the midbrain. The cerebellum has the dual effects of facilitation and inhibition of muscle tone (the two sides of the anterior lobe of the cerebellum, which belong to the cerebellar hemisphere, are one of the central sites that facilitate muscle tension), indicating that muscle tension is still dominant in this case. ^[5]