Dehydration of brain cells
Introduction
Introduction Increased extracellular fluid osmotic pressure can cause a series of symptoms of central nervous system dysfunction, including lethargy, muscle twitching, coma, and even death. It belongs to hypertonic dehydration. When the brain volume is significantly reduced due to dehydration, the vascular tension between the skull and the cerebral cortex increases, which can lead to rupture of the vein and local intracerebral hemorrhage and subarachnoid hemorrhage.
Cause
Cause
When the osmotic pressure of the cells is increased, in order to maintain the osmotic balance between the inner and outer cells, the intracellular water is extravasated, causing dehydration of the dehydrated brain cells in the cells, which manifests a disturbance of consciousness, irritability, stiff neck, and severe angulation , muscle tremor, local or body twitching. There are even sequelae. The capillary endothelial cells in the brain tissue are closely connected with the brain cells, and there is no interstitial between the blood and the brain. When the brain cells are dehydrated, the water directly flows into the blood circulation. Since the brain tissue is enclosed in the cranial cavity, the shrinkage of the brain cells can reduce the intracranial pressure, and the blood pressure of the heart pump does not change, and the result can cause cerebral vasodilation; in severe cases, it can cause cerebral hemorrhage or thrombosis. Due to different causes, the following changes can be made:
1 In the case of pure water loss, the ratio of water loss inside and outside the cell is equal to the ratio of its capacity, ie 2:1. If the patient's water loss is 90ml/kg, the intracellular fluid loses 60ml/kg, and the external fluid loses only 30ml/kg. Therefore, the symptoms of extracellular fluid dehydration, such as poor circulation, low urine, and eye socket subsidence are not obvious.
2 Loss of hypotonic liquid can be regarded as loss of part of the isotonic solution and part of pure water. Loss of isotonic fluid only causes dehydration of extracellular fluid. One third of the loss of pure water is lost from extracellular fluid. Therefore, patients may have extracellular fluid dehydration, but due to extracellular sodium, intracellular water extravasation The extracellular dehydration is partially corrected, so the extracellular fluid dehydration symptoms are relatively mild.
3 salt poisoning increased the extracellular fluid capacity, can cause pulmonary edema, heart failure and so on. Hypernatremia can cause hyperosmolar diuresis, but the concentration of urinary sodium is lower than blood [Na+], and can not correct high sodium, and eventually can cause hypertonic dehydration.
Examine
an examination
Related inspection
Brain CT examination brain MRI examination EEG examination brain nerve examination
Common diseases of brain cell dehydration:
Moderate hypernatremia is mainly the clinical manifestation of dehydration of brain cells, patients with irritability, dizziness, fatigue, etc.; severe patients with severe brain cell dehydration, brain tissue congestion, nerve cell lysis, mainly neuropsychiatric symptoms, such as sorrow, irritability Uneasy, manic, paralyzed, dysfunctional, hallucinatory, fainting, etc., accompanied by the inherent manifestations of dehydration, such as thirst, dry mouth, difficulty swallowing, hoarseness, increased heart rate, reduced skin sweating, dryness and skin elasticity decline. When the water loss reaches 15%, the patient may have hyperosmolar coma, hypovolemic shock, urinary closure, and acute renal failure.
Neonatal hyperglycemia, plasma hyperosmotic state, extracellular fluid extravasation, cerebral vascular dilatation, increased blood volume, hypertonic dehydration of brain cells, severe intracranial hemorrhage, hyperglycemia can also occur osmotic diuresis, water And a large amount of electrolytes are lost, causing dehydration and even shock.
Pregnant women drink alcohol: alcohol can also dehydrate fetal brain cells, even if pregnant women drink more than 400 ml of wine may cause fetal brain damage.
Diagnosis
Differential diagnosis
Isotonic dehydration: also known as isotonic dehydration. Water and sodium are lost in proportion, and the osmotic pressure of extracellular fluid is unchanged. The blood sodium is maintained in the normal range (130-150mmol/1). The majority of the dehydration encountered in the clinic belongs to this category. Sometimes the proportion of water loss and sodium loss may not be the same, but if the degree is not heavy, the kidney function is good. The body fluid can be maintained in an isotonic state by the regulation of the kidney. When isotonic dehydration, the extracellular fluid is dehydrated. Because the osmotic pressure inside and outside the cell is equal, there is no obvious change in the intracellular fluid. The clinical only has the dehydration sign caused by the decrease of extracellular fluid, and there is no manifestation of brain cell dehydration or edema.
Hypotonic dehydration can move water from the extracellular fluid to the intracellular fluid with relatively high osmotic pressure. On the one hand, it causes cell edema (such as brain cell edema), on the other hand, the extracellular fluid is further reduced, and the hypovolemia is further aggravated. . It can be seen that the intracellular fluid is not lost or even increased during hypotonic dehydration, mainly due to the significant decrease of extracellular fluid, accompanied by decreased blood volume and peripheral circulatory failure, often with venous collapse, decreased arterial blood pressure, and fine pulse. speed.
Hypertonic dehydration (hypertonic dehydration): also known as primary dehydration or hypernatremia with decreased extracellular fluid, characterized by loss of water more than loss of sodium, serum sodium concentration >150mmol / L, plasma osmotic pressure >310mOsm /L.
Common diseases of brain cell dehydration: moderate hypernatremia is mainly the clinical manifestation of brain cell dehydration, patients with irritability, dizziness, fatigue, etc.; severe patients with severe brain cell dehydration, brain tissue congestion, nerve cell lysis, nerve Psychotic symptoms, such as sorrow, irritability, mania, paralysis, dynamism, hallucinations, syncope, etc., accompanied by the inherent manifestations of dehydration, such as thirst, dry mouth, difficulty swallowing, hoarseness, heart rate The skin is reduced in sweating, dryness and decreased skin elasticity. When the water loss reaches 15%, the patient may have hyperosmolar coma, hypovolemic shock, urinary closure, and acute renal failure. Neonatal hyperglycemia, plasma hyperosmotic state, extracellular fluid extravasation, cerebral vascular dilatation, increased blood volume, hypertonic dehydration of brain cells, severe intracranial hemorrhage, hyperglycemia can also occur osmotic diuresis, water And a large amount of electrolytes are lost, causing dehydration and even shock.
Pregnant women drink alcohol: alcohol can also dehydrate fetal brain cells, even if pregnant women drink more than 400 ml of wine may cause fetal brain damage.
