Hydrocephalus in children

Introduction to children's hydrocephalus Hydrocephalus refers to the accumulation of excessive cerebrospinal fluid in the ventricles and subarachnoid space. If a large amount of cerebrospinal fluid accumulates in the subarachnoid space on the surface of the cerebral hemisphere, it is called subdural water cyst or subdural effusion, and the ventricular system. Excessive fluid volume is called intraventricular hydrocephalus. Pediatric hydrocephalus is more common in neonates and infants, often accompanied by enlarged ventricular system, increased intracranial pressure and increased head circumference. basic knowledge The proportion of illness: 0.087-0.1% (the incidence of hydrocephalus in newborns is 0.87/1000. In children with a history of meningocele, the incidence of hydrocephalus is about 30%.) Susceptible people: children Mode of infection: non-infectious Complications: intraventricular hemorrhage, brain abscess, abdominal pain

Causes of hydrocephalus in children

Congenital dysplasia (30%):

(1) cerebral aqueduct stenosis, gliosis and septal formation: the above lesions can cause infarction of the cerebral aqueduct, which is the most common cause of congenital hydrocephalus, usually sporadic, sexually linked hereditary aqueduct Stenosis accounts for only 2% of all congenital hydrocephalus.

(2) Arnold-Chiari malformation: due to cerebellar tonsil, medulla and fourth ventricle invaded into the spinal canal, causing cerebrospinal fluid circulation blocked by hydrocephalus, often accompanied by spina bifida and meningocele.

(3) Dandy-Walker malformation: hydrocephalus caused by congenital occlusion of the fourth ventricle and lateral holes.

(4) Flat skull base: often combined with Arnold-Chiari malformation, blocking the fourth ventricle outlet or ring pool, causing hydrocephalus.

(5) Others: no cerebral malformation, cartilage dysplasia, brain penetrating malformation, fifth, cerebral ventricle cysts, etc. can cause hydrocephalus.

Birth injury (30%):

In congenital hydrocephalus, congenital dysplasia accounts for about 2/5, while non-developmental causes account for 3/5. Intracranial hemorrhage caused by neonatal hypoxia and birth injury. Meningitis secondary adhesion is congenital. Common causes of hydrocephalus, neonatal intracranial tumors and cysts, especially in the posterior fossa tumors and choroid plexus papilloma often lead to hydrocephalus.

Tissue damage around the ventricles (30%):

The production process and formation of cerebrospinal fluid in children are the same as those in adults, with an average of 20ml/h, but the clinical features of hydrocephalus are different. Children's hydrocephalus is mostly caused by congenital and inflammatory lesions. Adult hydrocephalus is intracranial. Tumors, subarachnoid hemorrhage and trauma are more common. Anatomically, stenosis or obstruction can occur in any part of the cerebrospinal fluid pathway. Hydrologically, hydrocephalus is due to the absorption disorder of cerebrospinal fluid. As a result, the formation and absorption of cerebrospinal fluid is unbalanced, and the cerebrospinal fluid is increased. The increase of intracranial pressure changes the morphological structure of the brain tissue itself, resulting in increased pressure on the ventricular wall and progressive expansion of the ventricle. Some people use the lumbar perfusion method to study the traffic brain volume. The water patient found that in the range of normal intracranial pressure, higher than the intracranial pressure at rest, the absorption capacity of cerebrospinal fluid is greater than the ability to generate, called cerebrospinal fluid absorption reserve capacity, the size of the ventricle is not related to the ability of cerebrospinal fluid to absorb reserve, but the expansion of the ventricle Caused by the increase in the elasticity of the brain tissue, which in turn increases the amplitude of the intracranial cerebrospinal fluid pulse pressure, which produces the ventricle Sex expand, increase flexibility and force the brain ventricles of the surface area is closely related to ventricular expansion.

In addition, the transient intraventricular pulsation pressure increases the impact of the aqueduct, and there is tissue damage around the ventricle, resulting in secondary ventricular enlargement. The main cause of normal intracranial hydrocephalus is the difference in pressure between the ventricle and the subarachnoid space. Rather than the absolute value of intracranial pressure, this type of hydrocephalus obstruction is at the end of the cerebrospinal fluid circulation, that is, the subarachnoid space. Although this condition has a balance of cerebrospinal fluid production and absorption phase, the abnormal pressure gradient acts on Ventricular dilatation can still occur between the surface of the brain and the ventricles. If the injury is in a site that is far away from the cerebrospinal fluid, such as the sagittal sinus, there is no pressure gradient difference in the cerebral cortex, and the ventricles are not enlarged. This is manifested in benign intracranial hypertension. The patient, at this time, has an absorption disorder of cerebrospinal fluid and an increase in intracranial pressure. There is no enlargement of the ventricle. An increase in the pressure of the superior sagittal sinus can produce external hydrocephalus in infants. At this time, the subarachnoid space on the surface of the cortex is enlarged. This is because the pressure gradient difference does not exist in the cortical performance, but between the ventricle and the skull, resulting in the expansion of the skull. Clinically, children with giant cranial disease are often accompanied by cobwebs. Under cavity to expand, there are reports of benign intracranial hypertension and brain child of water and more related to intracranial venous hypertension, benign intracranial hypertension patients all over 3 years of age, cranial suture closure children.

In infants and young children, even if the brain is severely accumulating water, the ventricle enlarges obviously, and the anterior iliac puncture pressure is still within the normal range of 20-70mmH20. In the case of accommodating abnormal cerebrospinal fluid, the intracranial pressure changes are still small, which is The cranial suture of infants with hydrocephalus is related to the anterior or posterior patency. Some people think that this compensatory ability is important for protecting the intelligence of infants and young children. It also suggests that infants with hydrocephalus cannot change their intracranial pressure as a means of shunt therapy. Signs, hydrocephalus once secondary cerebrospinal fluid circulation and absorption disorders, in addition, most of the children with hydrocephalus associated with spina bifida caused by the primary aqueduct stenosis, the main part of the obstruction in the lower third ventricle Especially at the exit, accompanied by dilatation of the ventricles, external compression of the midbrain, resulting in mechanical distortion of the midbrain, resulting in secondary midbrain aqueduct obstruction, a phenomenon in children with hydrocephalus and other causes of hydrocephalus It can happen that children with traffic hydrocephalus will also block the midbrain aqueduct due to changes in brain tissue itself after a period of diversion.

The degree of hydrocephalus determines the morphological changes of the brain tissue. Due to the occipital, the ventricle of the ventricle is more convex and the nucleus of the frontal horn is more, the tissue is more tough and other morphological structural features, and the top brain tissue after water accumulation is selectively thinned, congenital The hydrocephalus of the brain penetrating malformation shows local cystic enlargement in the brain. When the compliance of the cyst wall exceeds the compliance of the ventricle, the cystic enlargement is more obvious. At this time, the patient can show focal neurological deficit and seizure.

In children with hydrocephalus biopsy, in the early stage, edema around the ventricle and axonal degeneration, followed by edema subsided, glial cell proliferation around the ventricles, with the loss of nerve cells in the later stage, atrophy of the cerebral cortex, and axonal dispersal At the same time, the ependymal cells around the ventricle are vulnerable to damage. The early ependymal cells are detached and flattened. After the cell junction is broken, most of the ependymal cells disappear and the glial cells grow on the cerebral ventricle. These changes often With the edema around the ventricle and the loss of axonal myelin, the myelin formation of the corpus callosum is delayed, the neurons of the cortex are involved, the dendritic branches of the pyramidal cells are reduced, the dendrites are less, and dendritic varices occur. Histological changes lead to clinical manifestations such as mental retardation in children, changes in limb paralysis and intelligence.

Biochemical analysis of cerebrospinal fluid is helpful in judging the prognosis of hydrocephalus. Immunoelectrophoresis measures the increase of total protein in cerebrospinal fluid, suggesting intraventricular and external obstruction. At the same time, it is also related to white matter damage and blood-cerebrospinal fluid barrier destruction, without degeneration. Disease; the concentration of fatty acids in cerebrospinal fluid is proportional to the increase of intracranial hypertension. After the release of obstructive hydrocephalus, the concentration of fatty acids decreases. If the postoperative persistence increases, it indicates a poor prognosis. Astragalus and hypoxanthine are in the cerebrospinal fluid. The concentration can reflect the condition of cerebral hypoxia after enlarged brain ventricle. After the correction of intracranial hypertension, the concentration of hypoxanthine decreases; ganglioside is related to severe mental retardation after hydrocephalus in children, and children with normal intelligence are hydrocephalus. The gangliosides in the cerebrospinal fluid are normal, and cyclic adenosine is associated with intraventricular infection in children with hydrocephalus.

Pediatric hydrocephalus prevention

1, safe production, beware of suffocation, birth injury. When pregnant women are born, they must be produced in hospitals with good environmental conditions. Do not delay the labor process during the production process, beware of perinatal suffocation and prevent birth injuries. This is an important part of preventing the occurrence of perinatal hydrocephalus.

2, strengthen early prenatal diagnosis and early termination of pregnancy to prevent the birth of hydrocephalus. Prenatal diagnosis of hydrocephalus is an important way to prevent the birth of hydrocephalus. Due to the obvious hydrocephalus, it can be detected by B-ultrasound at 12-18 weeks of pregnancy. Therefore, it is necessary to strengthen the application of B-ultrasound in prenatal diagnosis, early termination of pregnancy, prevention of birth of hydrocephalus, and reduction of congenital brain. The birth rate of stagnant water.

3, to promote the appropriate age of birth from the relevant data show that the incidence of hydrocephalus teratoma has an increasing trend with the increase in the age of pregnant women. Generally, the incidence rate is the lowest in the 25-29 age group, but the difference is not significant. The incidence rate increases after 30 years old.

Therefore, the promotion of proper age and birth has a certain significance on how to prevent the occurrence of fetal hydrocephalus.

Pediatric hydrocephalus complications Complications, intraventricular hemorrhage, brain abscess, abdominal pain

If children with hydrocephalus undergo surgery, the following complications may occur:

1. Shunt system blocking

The most common complication can occur anywhere from the operating room to years after surgery, most commonly at 6 months after surgery.

(1) Blockage of the proximal end (ventricle end) of the shunt: it may be caused by blockage of blood clots, adhesion of choroid plexus or adhesion of brain tissue.

(2) Blockage of the distal end of the shunt (abdominal or atrial): Common causes include: 1 The position of the tip of the catheter is incorrectly placed (eg under the skin) and does not enter the abdominal cavity. 2 multiple replacement shunts and abdominal infections are easy to form abdominal pseudocysts, the incidence rate is 1.7% to 4.5%, abdominal pain can occur, subcutaneous effusion at the shunt device. 3 The tip of the catheter is blocked by the omentum, blood clots, and the like.

(3) Intraventricular hemorrhage, increased inflammation of cerebrospinal fluid protein or cellulose after ventriculitis and brain surgery can block the shunt valve. Dropping of the catheter junction is also a common cause of shunt clogging.

Once the shunt is blocked, the patient's hydrocephalus symptoms and signs will recur. CT examination shows that the ventricle is re-expanded, mainly manifested as headache, nausea, vomiting and lethargy. The symptoms of onset are various and can suddenly start severely. Can be slowly onset, rapid intracranial pressure, severe increase can lead to coma, chronic symptoms include irritability, poor performance in school or slow development of physiological development, occasionally new epilepsy or increased number of epilepsy.

The signs caused by obstruction of the shunt system are related to the increase of clinical intracranial pressure and the abnormal function of the shunt. For the patients with ventricular dilation after imaging examination of the ventricle shunt, the reexamination shows that the ventricle is enlarged again, suggesting that the shunt system is blocked, for no prior imaging. Patients with data, although there may be a shunt tube obstruction, but the ventricle is normal or slightly enlarged, it is difficult to judge whether there is a shunt system obstruction at this time, this situation is more common in the diseased children, due to congenital malformation factors, The seemingly normal ventricle is not normal. At this time, the obstruction part of the shunt system should be judged first, and then the shunt device should be replaced or corrected. The judgment method: the puncture reservoir can not extract the cerebrospinal fluid or the valve can not be filled again, suggesting the ventricle end If it is difficult to crush the valve, it means the valve itself or the abdominal cavity or atrial end obstruction. For the obstruction of the shunt system caused by excessive protein and cellulose content of cerebrospinal fluid, attention should be paid to prevention, such as controlling bleeding, inflammation, etc., first to conduct external drainage of cerebrospinal fluid. After the test is normal, the shunt is performed again. If there is a suspected abdominal pseudocyst, After the diagnosis of abdominal ultrasonography, the drainage tube should be removed, the pseudocyst should be removed, and the drainage tube should be reset in other parts of the abdominal cavity; if the pseudocyst is caused by infection, the shunt should be performed after infection control.

2. Infection

Infection is still one of the major complications after cerebrospinal fluid shunt. Infection can cause mental damage to the patient, form a compartment in the ventricle, and even die. Although after decades of efforts, many medical centers report an infection rate of 5%. ~10%, according to the affected parts, the infection is divided into: wound infection, meningitis, peritonitis, shunt infection, most infections occur within 2 months after shunt.

The clinical manifestations are related to the location of the infection. The wound infection has fever, and the incision or shunt tube is red and swollen under the skin. When the infection time is long, there may be wounds and pus. For chronic wound infection, the shunt tube can be exposed, the skin of the infant is thin, and the shunt tube is easy to skin. Wounds cause wound infection, cerebrospinal fluid leakage of the incision often causes pollution, and then forms infection, meningitis or ventriculitis patients have fever, headache, irritability and neck stiffness, peritonitis is rare, typical manifestations of fever, anorexia or vomiting And abdominal tenderness, routine blood tests often increase polymorphonuclear leukocytes, there is no clear meaning for blood culture in patients with extraventricular peritoneal shunt, but for patients with fever should be blood culture, and should do urine or other infection sites such as Bacterial culture of the wound, CT or MRI of the head can confirm the size of the ventricle, not only can determine whether the shunt tube is blocked, but also can decide whether to take out the shunt tube or do extraventricular drainage.

For all patients without wound infection or subcutaneous shunt tube exposure, the cerebrospinal fluid should be taken by puncture and shunt liquid storage for cell counting, Gram smear or culture to confirm the diagnosis of infection. Once diagnosed, the shunt device should be removed immediately and converted into extraventricular drainage. , or through the waist drainage, and systemic anti-infective treatment or antibiotics intraventricular, intrathecal medication, in addition, should also consider the possibility of fungal infection, after infection control, re-flow shunt, intraoperative strict aseptic operation is the key to prevent infection Link.

3. Over- or under-split

(1) excessive shunt: more common in children, patients with typical orthostatic headache, increased position and ease after lying position, CT scan showed small ventricle, cerebrospinal fluid pressure can be less than 0.59kPa (60mmH2O), the most effective at this time The treatment is to replace the low pressure valve with a high pressure valve (0.196 to 0.294 kPa (20 to 30 mm H2O) higher than the original.

(2) Chronic subdural hematoma or effusion: more common in patients with positive pressure hydrocephalus, most of the reasons for the application of low-impedance shunt caused by excessive drainage of cerebrospinal fluid, intracranial hypotension, often no obvious clinical manifestations, review CT Or MRI shows cortical collapse and subdural hematoma or effusion, using a larger impedance shunt device or installing an anti-siphon valve to avoid excessive drainage, may prevent this complication, mild subdural hematoma or effusion, Can be conservatively treated, obvious or symptomatic subdural hematoma or effusion, should be treated surgically, the former is feasible for drainage drainage, the latter is feasible effusion-peritoneal shunt.

(3) Insufficient shunt: the patient's postoperative symptoms did not improve. The imaging examination found that the ventricular enlargement still exists or is not obvious. The main reason is that the shunt valve pressure used is not proper, resulting in poor cerebrospinal fluid discharge, and the valve with appropriate pressure needs to be replaced. To determine the actual needs of the patient before surgery, choosing the right pressure valve is the key to prevent this complication.

4. Fissure ventricle syndrome

The incidence of slit ventricle syndrome is 0.9% to 55%, which can occur after surgery in patients with or without traffic hydrocephalus.

Fissure ventricle syndrome refers to symptoms of increased intracranial pressure, such as headache, nausea, vomiting and ataxia, slow response, lethargy, etc. after several years of shunt surgery (mean, 4.5 to 6.5 years). Less than normal, check that the shunt valve is pressed and then refilled slowly, suggesting that the shunt end of the shunt tube is blocked.

The pathogenesis of fissure ventricle syndrome is caused by long-term excessive drainage of cerebrospinal fluid: when the cerebrospinal fluid is drained a lot, the ventricles shrink, and the ventricle of the shunt tube is functionally blocked. When the cerebral ventricular compliance is good, the accumulation of cerebrospinal fluid can cause the expansion of the ventricle. Thereby the blocking is released and the shunt function is restored. Long-term repeated shunt tube functional obstruction can cause cerebrospinal fluid to ooze out of the subventricular zone around the ventricle and extravasation along the shunt, damaged ependymal fibrosis, paraventricular hyperemia and gliosis, etc., so that the patient's ventricle conforms The gradual decrease in sex, although the cerebrospinal fluid continues to increase, the intracranial pressure continues to increase, but the ventricle is no longer enlarged, the shunt can not be removed, resulting in high intracranial pressure, using anti-siphon device, replacing the shunt to prevent fissure ventricular syndrome There is no positive significance. It has been reported that sub-muscular decompression can alleviate the symptoms of patients and reduce their incidence.

5. Other complications

(1) Complications at the ventricle end: When the ventricle end of the shunt tube is mistakenly inserted next to the optic nerve pathway, it can cause blindness in one eye, hemianopia in the same direction or hemianopia on both sides of the ventricle, and there are reports that the ventricle is moved to the back of the optic chiasm and the brainstem. Using neuroendoscopy, placing the shunt tube under direct vision can avoid mis-insertion, such as acute intracranial hypertension such as optic disc edema after shunt, or visual field, visual acuity change, should consider the displacement of the ventricular end shunt tube, once To confirm the diagnosis, the ventricle end of the shunt should be reset.

(2) Complications at the peritoneal cavity:

1 organ perforation: mostly perforation of the colon, can cause peritonitis, meningitis or brain abscess. Can also puncture the stomach, vagina, bladder, etc., can not show peritoneal irritation, but only as a shunt tube blockage, or water and electrolyte imbalance caused by the loss of cerebrospinal fluid, such as the discovery of organ perforation, surgical removal of the shunt, And replace the shunt method.

2 shunt tube displacement: can be displaced to the chest, abdominal wall and neck subcutaneous, or scalp cap-like aponeurosis, occasionally worn through the diaphragm, moved to the chest, pericardium, causing pleural effusion, and even puncture the heart, resulting in Cardiac dysfunction, when the shunt tube is moved under the skin or under the aponeurosis, the shunt can be blocked, and the shunt or line shunt should be replaced. If the chest X-ray film confirms that the shunt tube is moved to the chest or the heart, the tube should be surgically removed immediately. To prevent the displacement, the shunt can be fixed at the movable part.

3 other: cerebrospinal fluid navel leak, the end of the shunt tube is entangled and cause intestinal obstruction.

(3) epilepsy: the incidence rate is about 5%, more than the angle of the puncture of more than the occipital puncture, the use of anti-epileptic drugs to control seizures, while eliminating the possible causes of intracranial hemorrhage, inflammation, hydrocephalus recurrence, increased intracranial pressure, and Handle accordingly.

Symptoms of hydrocephalus in children Symptoms Symptoms Before sputum fullness, irritability, spurs, separation of lower limbs, scissors, gait, scoliosis, mental retardation, dehydration, palpebral palsy, varicose, nystagmus

Compared with adults, the clinical manifestations of hydrocephalus in children vary according to the age of onset of the patient. In infants with acute hydrocephalus, the symptoms of cranial hypertension are usually obvious, the fracture of the bone is split, the anterior sac is full, the scalp is thinned and the scalp vein is clear. It can be seen that there is anger, and there is a phenomenon of light transmission from the head when the head is illuminated with strong light. The head of the percussion is a solid drum sound, that is, the cracking sound is called the Macewen sign, the sick child is easy to provoke, the expression is indifferent and the diet is poor. Abnormal crying with continuous high-profile shortness, the eyeballs are in a downward view, the upper eyelids are not accompanied by sagging, and the lower half of the eyeball sinks to the lower eyelid margin. Some of the corneas are above the lower temporal margin, and the upper eyelids are turned white, also known as sunset. Phenomenon, separation on the eyes, lower vision, and gaze numbness, nystagmus, etc., which is related to the dysfunction of the brainstem nucleus around the aqueduct. As the hydrocephalus develops further, the brain stem shifts downward. Nerve and other cranial nerves are pulled and eye movement disorder occurs. In children under 2 years of age, due to abnormal eye movements, amblyopia occurs, and optic disc edema is not obvious and rare in congenital hydrocephalus, but Retinal veins is a reliable sign of hydrocephalus.

Abnormal movements mainly include paralytic spasm of the limbs, mainly lower limbs. The symptoms are mild, the feet are tight, the feet are drooping, and the gait is severe when it is severe. It is also called the gait of the scissors. Sometimes it is difficult to distinguish it from the cerebral palsy. And the lower hypothalamus, the funnel is involved, can occur a variety of endocrine dysfunction, such as youth precocious or backward and growth short and other symptoms of decreased hormone levels, in addition, syringomyelia with hydrocephalus often occurs lower extremity dysfunction, When the syringomyelia is associated with spinal cord hypoplasia, scoliosis often occurs.

Examination of children's hydrocephalus

Puncture is a simple method for diagnosing and differentially diagnosing congenital hydrocephalus.

Anterior puncture

The anterior iliac crest was inserted 2 cm from the midline of the anterior iliac crest to determine whether there was subdural effusion and chronic subdural hematoma. If it was negative, it was slowly stabbed into the ventricle. Every time it entered 1-2 cm, it was observed whether there was cerebrospinal fluid outflow. Flow out and immediately measure pressure and cerebral cortex thickness.

2. Ventricular chamber, lumbar puncture double puncture test

At the same time for the front and waist wear measurement, the bed head is raised by 30 ° and lowered by 30 °, respectively, the pressure on both sides is recorded, if it is traffic hydrocephalus, the pressure on both sides can quickly reach the same level, such as complete obstruction Sexual hydrocephalus, it can be seen that the pressure on both sides is different; in some cases, the pressure on both sides changes slowly.

3. Cerebrospinal fluid phenol red test

It can be used to identify whether hydrocephalus is obstructive or traffictic. After the pressure is measured by double puncture test of ventricle lumbar puncture, 1 ml of neutral phenol red is injected into the ventricle. Under normal circumstances, phenol red appears in the cerebrospinal fluid released by lumbar puncture within 12 min. Inside, the cerebrospinal fluid droplets released from the waist are on the gauze impregnated with the alkaline liquid. When the phenol red appears, the color turns red. If it does not appear for more than 30 minutes, it indicates obstructive hydrocephalus, and 2 hours after the injection of phenol red is collected. In the urine within 12 hours, the amount of phenol red in the urine was measured to diagnose the obstruction.

Another method of examination is to inject 1ml of rouge into the ventricle. Under normal circumstances, it will drip from the lumbar puncture needle within 4 to 5 minutes. If it can not be dripped, it will be expressed as complete obstruction. For 10 to 15 minutes, the drip will be partial obstruction. .

4. Head circumference measurement

The head circumference of children with hydrocephalus can be increased to different extents. It can be found abnormal by measuring the head circumference regularly. The head circumference measurement generally measures the circumference, anteroposterior diameter (diameter) and interaural diameter (transverse diameter), normal neonatal head. The surrounding diameter is 33-35cm, 64cm for 6 months, 46cm for 1 year old, 48cm for 2 years old, and 50cm for 6 years old. When the head circumference is obviously beyond its normal range or the head circumference growth rate is too fast, the possibility of hydrocephalus should be highly suspected. .

5. Skull flat film

It can be seen that the skull is enlarged, the skull is thinned, the cranial suture is separated, and the anterior or posterior sacral opening is extended or delayed.

6. Brain CT

Cranial CT can accurately observe the presence or absence of hydrocephalus, the degree of hydrocephalus, obstruction, edema around the ventricle, etc., and can repeatedly observe the progress of hydrocephalus, providing the necessary objective indicators for judging efficacy and prognosis. There is no uniform reliable indicator of the degree of hydrocephalus and hydrocephalus in the brain CT. In 1979, Vassilouthis proposed the ventricle-cranial ratio as the posterior horn of the lateral ventricle (between the caudate nucleus) The ratio of the width to the distance between the same level of the inner skull plate, if the ventricle-cranial ratio is less than 0.15 is normal, if the ventricle-cranial ratio is between 0.15 and 0.23 for mild hydrocephalus, if the ventricle-cranial ratio is greater than 0.23 for severe brain Water.

Brain CT can identify many causes of acquired obstruction:

(1) intraventricular obstructive hydrocephalus: one side interventricular pore blockage (interventricular interstitial atresia) caused by unilateral hydrocephalus or asymmetrical hydrocephalus, which leads to the expansion of the lateral ventricle, when the bilateral compartment When the hole or the three ventricle holes are blocked to cause symmetrical hydrocephalus, the bilateral ventricles are dilated.

If the aqueduct is blocked (stenosis of the aqueduct), the lateral ventricle and the third ventricle may be dilated, and the size and position of the fourth ventricle are generally normal.

Obstruction at the exit of the fourth ventricle (lateral and median hole atresia) causes expansion of the whole ventricle system, especially the fourth ventricle, such as cystic changes in the fourth ventricle.

(2) cerebral obstructive hydrocephalus: cerebral obstruction often causes dilatation of the subarachnoid space in the proximal part of the ventricular system and obstruction. Cerebral angiography and ventriculography help to determine the obstruction site.

(3) "Constrictive hydrocephalus": Chiari type II malformation combined with spinal meningocele, the downward displacement of the rhomboid can form stenosis at the cranial-vertebral junction and posterior fossa and become an anatomical obstruction As a result, hydrocephalus occurs in the cerebrospinal fluid circulation disorder surrounding the rhomboid. In this case, the fourth ventricle is displaced downward, which is difficult to recognize in the normal position, and is usually found in the cervical spinal canal.

7.MRI

The MRI of hydrocephalus is the expansion of the ventricular system. The standard is the same as that of CT. On MRI, the presence or absence of hydrocephalus can be judged according to the following manifestations: 1 The degree of ventricular enlargement is not proportional to the size of the subarachnoid space. 2 The ventricle or horn of the ventricle is bulging or round. 3 The third ventricle is balloon-shaped, oppressing the thalamus and moving the hypothalamus down. 4 carcass rise and rise. 5 Cerebrospinal fluid penetrates into the recanalization of the ependymal membrane.

8.B-ultrasound

The ability to accurately measure the two frontal angles and the size of the entire lateral compartment, intrauterine ultrasonography of the fetus before birth is still an effective early diagnosis.

Diagnosis and diagnosis of hydrocephalus in children

diagnosis

During infants and young children, the diagnosis of hydrocephalus is an abnormal increase in the head. The size of the head circumference is not related to the age. The regular measurement of the head circumference of the baby will help to detect hydrocephalus early and can be found in typical signs. Pre-existing diagnosis and timely treatment, typical signs are small head, small eye drops, often strabismus, bright skin on the head, forehead vein engorgement, abnormal enlargement of the cardia and suture, except mental retardation In addition, because of the small changes in day-to-day, parents may not notice abnormal signs, and the disease develops progressively, that is, the so-called active hydrocephalus. If no measures are taken, many babies will die, and natural survivors will change statically. Hydrocephalus, manifested as mental retardation, various types of paralysis, visual impairment, including blindness and many other abnormalities.

In neonates, although there is enlargement of the ventricles or hydrocephalus, the anterior iliac crest can still be trapped, especially in infants with lighter weight after birth. Because of dehydration of the sick child, the head may be less than normal. In addition, premature babies may have intraventricular hemorrhage, often In the 6-14 weeks after the neonatal period, the ventricles are enlarged and the head circumference is abnormally increased, but this process is also self-limiting. Although the abnormal increase of the head circumference of children is an important sign of hydrocephalus, there is no relationship between the two. Absolute relationship, it is necessary to understand the whole process of the fetus including the perinatal period, continuous observation of ventricular dilatation, B-ultrasound is a simple and easy to use, non-invasive and repeatable reliable method to observe hydrocephalus patients.

After the diagnosis of progressive hydrocephalus is established, neuroimaging can be performed on head CT and magnetic resonance imaging (MRI), except for intracranial tumors, congenital malformations and cerebrospinal fluid obstructive lesions, water-soluble contrast agents and radionuclide scans. Helps diagnose the obstructive hydrocephalus, but generally limits the application.

Differential diagnosis

1. Chronic subdural effusion or hematoma: often has a history of birth injury, the lesion can be unilateral or bilateral, often with optic disc edema, negative fall sign, anterior fistula puncture subdural suction hemorrhagic or light yellow liquid Clear diagnosis, cerebral angiography, CT or MRI can also be identified.

2. Neonatal intracranial tumors: Neonatal intracranial tumors often have enlarged head circumference or secondary hydrocephalus, and can be diagnosed by ventriculography or CT scan and MRI.

3. Vitamin D deficiency: The head circumference can be enlarged into a square skull, the anterior ankle is enlarged, the tension is not high, and there are other manifestations of vitamin D deficiency.

4. Congenital giant cranial disease: no hydrocephalus sign, negative sign of the sun, no expansion of the ventricular system, no increase in intracranial pressure, CT scan can confirm the diagnosis.

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