What are the clinical manifestations of cerebellar herniation

I believe that for people who have never had brain hernia, the term brain hernia is still unfamiliar, but you must know that this disease is still very dangerous. If it is not rescued, the risk of death is relatively high. So what is brain hernia? In fact, to put it simply, our brain is like a ball, with the left and right brains on both sides. Normally, each is in its own position, but when a lesion occurs in the brain or the intracranial pressure increases, one side will squeeze towards the other, causing the tissues, nerves, and blood vessels in the brain to be squeezed, thus causing harm to the human body. However, the human body will feel uncomfortable during the process, so understanding the clinical manifestations of cerebellar herniation is the key to early treatment and improving survival rate.

According to the location of brain herniation, brain herniation is divided into the following three common categories: transtentorial notch herniation, foramen magnum herniation, and subfalcine herniation. Their clinical manifestations are as follows:

1. Transtentorial herniation

1. Symptoms of increased intracranial pressure: severe headache and frequent vomiting, which are more severe than before brain herniation, and irritability.

2. Changes in consciousness: manifested as drowsiness, light stupor or even coma, and slow or absent response to external stimuli.

3. Pupillary changes: The pupils on both sides are not of equal size. At the beginning, the pupil on the affected side is slightly smaller and the light reaction is slightly slower. Later, the pupil on the affected side gradually dilates and becomes slightly irregular. Direct and indirect light reactions disappear, but the pupil on the other side may still be normal. This is because the oculomotor nerve on the affected side is compressed and pulled. In addition, the affected side may also experience ptosis, exotropia, etc. If brain herniation continues to develop, bilateral pupil dilation and disappearance of light response may occur, which is caused by compression of the oculomotor nerve nucleus in the brainstem, leading to dysfunction.

4. Movement disorders: mostly occur on the opposite side of the dilated pupil, manifested as reduced or absent autonomous movement of the limbs. The continued development of brain herniation causes symptoms to spread to both sides, causing weakness in the limbs or intermittent head and neck tilting back, limbs straightening, and back hyperextension in opisthotonos, which is called decerebrate rigidity and is a characteristic manifestation of severe brainstem damage.

5. Disorders of vital signs: manifested as changes in blood pressure, pulse, respiration, and body temperature. In severe cases, blood pressure fluctuates, breathing becomes fast and slow, the face becomes flushed and sweats profusely, and sometimes the patient becomes pale and sweats. The body temperature may be as high as 41°C or as low as 35°C without rising. Finally, breathing stops, and the blood pressure drops and the heart stops beating, leading to death.

2. Foramen magnum hernia

Patients often only have severe headaches, repeated vomiting, disordered vital signs, and neck stiffness and pain. Changes in consciousness occur later, there are no pupil changes, and respiratory arrest occurs earlier.

3. Herniation below the falx cerebri

It causes softening and necrosis of brain tissue in the compressed part of the medial surface of the affected cerebral hemisphere, resulting in symptoms such as mild paralysis of the contralateral lower limbs and urination disorders.