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Pyogenic meningitis (abbreviated as brain) is a meningitis inflammation caused by various purulent bacteria. Some children with lesions involving the brain parenchyma are common central nervous system infectious diseases in children, especially in infants and young children. Clinical features are acute fever, convulsions, disturbance of consciousness, increased intracranial pressure, meningeal irritation, and cerebrospinal fluid purulent changes. With the continuous development of meningococcal, Haemophilus influenzae, and pneumococcal vaccines, the prognosis of this disease has improved significantly, but the mortality rate is still between 5% and 15%, and about 1/3 of survivors Various neurological sequelae remain, and the prognosis of this disease is more serious in infants younger than 6 months.

Basic Information

Visiting department

Pediatrics, Neurology

Multiple groups

Children under 5 years

Common causes

Meningococcal, Streptococcus pneumoniae, and Haemophilus influenzae infections

Common symptoms

Acute fever, convulsions, disturbance of consciousness, increased intracranial pressure, and meningeal irritation

Causes of pyogenic meningitis in children

Many pyogenic bacteria can cause this disease. However, more than two-thirds of the children are caused by meningococcus, pneumococcus, and Haemophilus influenzae. Young infants and newborns under 2 months, and those with primary or secondary immunodeficiency disease are prone to enteric gram-negative bacilli and staphylococcal meningitis. The former is most common in E. coli, followed by proteus, Pseudomonas aeruginosa or Aerobacter. However, unlike in foreign countries, -hemolytic streptococcal infections in group B are rare in China. Pathogenic bacteria can invade the meninges in many ways:

1. The most common way is to reach the meningeal microvessels through the blood stream, that is, bacteremia. When children's immune defense function is reduced, bacteria cross the blood-brain barrier and reach the meninges. Most pathogenic bacteria invade the bloodstream from the upper respiratory tract, and the skin, gastrointestinal mucosa, or umbilicus of the newborn is often the invasion portal for infection.

2. Infections of adjacent tissues and organs, such as otitis media, mastoiditis, etc., spread to the meninges.

3. There is a direct channel with the cranial cavity, such as skull fracture, cutaneous sinus tract or cerebrospinal membrane bulging, so bacteria can directly enter the subarachnoid space.

Clinical manifestations of pyogenic meningitis in children

90% of the brains are children under 5 years of age, and the peak of the disease is under 1 year old. Haemophilus influenzae brains are more concentrated in children aged 3 to 3 years. Cerebral encephalopathy occurs throughout the year, but Streptococcus pneumoniae is more common in winter and spring, while meningococcus and Haemophilus influenzae are more common in spring and autumn, respectively. Most are onset. Some children have a history of upper respiratory or gastrointestinal infections several days before their illness. Meningococcal and Haemophilus influenzae sometimes cause joint pain.

Typical clinical manifestations can be briefly summarized into three aspects:

1. Symptoms of infection and acute brain dysfunction

This includes fever, irritability, and progressively worsening consciousness. As the illness worsened, the child gradually went from apathetic, lethargic, lethargic, and coma to deep coma. About 30% of children have recurrent systemic or localized seizures. Meningococcal infections often have stasis, petechiae, and shock.

2. Increased intracranial pressure

Including headaches and vomiting, babies have full front palate, increased tension, and increased head circumference. When combined with cerebral hernia, there are signs such as irregular breathing, sudden increase in consciousness disturbance or large pupils.

3. Meningeal sign

Neck rigidity is most common, and others such as Krebs sign and Brinell sign are positive.

4. Infant and neonatal brain manifestations less than 3 months

Most atypical, the main differences are:

(1) The body temperature can be high or low, or not feverish, or even the temperature does not rise;

(2) The manifestation of increased intracranial pressure is not obvious. Infants do not complain of headaches and may only spit, scream or crack the craniotomy;

(3) Convulsions can be atypical, such as facial, limb focal or multifocal tics, local or systemic myoclonus, or blinking, irregular breathing, breathlessness and other insidious attacks;

(4) Meningeal irritation is not obvious. It is related to the infant's underdeveloped muscles, weak muscles and poor response.

5. Complications and sequelae

(1) 30% to 60% of subdural effusions are complicated by subdural effusions. If asymptomatic patients are added, the incidence can be as high as 80%. The disease mainly occurs in infants under 1 year of age. After effective brain treatment for 48 to 72 hours, the cerebrospinal fluid improves, but the body temperature does not decline or rises after the temperature drops; or after the general symptoms improve, there are symptoms such as disturbance of consciousness, convulsion, anterior condylar bulge, or increased intracranial pressure, or even People with progressive exacerbations should first suspect the possibility of the disease. Cranial light transmission examination and CT scan can assist the diagnosis, but the final diagnosis still depends on subdural puncture to release effusion, and also achieve the purpose of treatment. The effusion should be sent for routine and bacteriological examination. The volume of subdural fluid in normal infants does not exceed 2m1, and the amount of protein is less than 0.4g / L.

(2) Ventricular meningitis occurs mainly in infants whose treatment is delayed. Children with fever, fever, convulsions, unconsciousness improvement, progressive aggravation of neck stiffness and even angular arch reversal under effective antibiotic treatment, cerebrospinal fluid always fails to normalize, and when CT sees expansion of the ventricle, this disease needs to be considered and the diagnosis depends on The lateral ventricle was punctured, and the cerebrospinal fluid in the ventricle was abnormal. Treatment is mostly difficult, with high mortality and disability.

(3) Inflammation of abnormal antidiuretic hormone secretion syndrome Stimulates the excessive secretion of antidiuretic hormone in the posterior pituitary gland, causing hyponatremia and low blood plasma osmotic pressure, which may exacerbate brain edema, cause convulsions and disturbance of consciousness, or directly result from hyponatremia Causes a seizure.

(4) Adhesion of hydrocephalus inflammation exudate blocks the ventricle of cerebrospinal fluid in the ventricle, such as aqueduct, lateral ventricle or median foramen, and causes non-traffic hydrocephalus; it can also damage arachnoid particles due to inflammation , Or intracranial venous sinus embolism caused cerebrospinal fluid reabsorption disorder, resulting in hydrocephalus. After the occurrence of hydrocephalus, the child developed irritability, drowsiness, vomiting, and seizures, progressively enlarged skulls, osteosynthesis, enlarged anterior condyles, broken jugs, and dilated scalp veins. By the end of the disease, persistent intracranial hypertension causes degenerative atrophy of the cerebral cortex, and children with progressive mental retardation and other neurological decline.

(5) 10% to 30% of children with neurological dysfunction have cochlear labyrinth because of inflammation. Others include mental retardation, cerebral palsy, epilepsy, visual impairment, and abnormal behavior.

Pediatric purulent meningitis examination

Cerebrospinal fluid examination

It is an important basis for the diagnosis of this disease. Typical cases show increased pressure and cloudy appearance like rice soup. The total number of white blood cells increased significantly, 1000 × 10 / L, but 20% of the cases may be below 250 × 10 / L, mainly classified as neutrophils. The sugar content is often significantly reduced and the protein is significantly increased.

Confirmation of pathogenic bacteria is of great significance for clear diagnosis and guidance of treatment. Gram staining of smears is simple and easy to detect pathogenic bacteria, and the positive rate is even higher than that of bacterial culture. Those with a positive bacterial culture should be sent to a drug sensitivity test. A variety of immunological methods based on the latex particle agglutination method can detect specific antigens of pathogenic bacteria in cerebrospinal fluid, which is of reference value for the diagnosis of patients who cannot detect pathogens by smear and culture.

2. Other

(1) Blood culture All cases of suspected brain should be blood cultured to help find pathogenic bacteria.

(2) Finding bacteria on skin ecchymosis and petechiae is an important and simple method for discovering meningococcus.

(3) The total number of leukocytes in peripheral blood is obviously increased, mainly neutrophils. However, in patients with severe infections or irregular treatment, there may be a decrease in the total number of white blood cells.

(4) Serum procalcitonin may be one of the specific and sensitive detection indicators for distinguishing aseptic meningitis and brain metastasis. Serum procalcitonin> 0.5ng / ml indicates bacterial infection.

(5) Neuroimaging Skull MRI can more clearly reflect brain parenchymal lesions than CT. Repeated examinations during the course of the disease can find complications and guide the implementation of intervention measures. Enhanced imaging can reveal inflammatory changes such as meningeal sclerosis.

Diagnosis of pyogenic meningitis in children

Early diagnosis is a prerequisite to ensure that children receive early treatment. All infants and young children with acute fever onset and accompanied by repeated convulsions, disturbance of consciousness or increased intracranial pressure should pay attention to the possibility of this disease, and should further rely on cerebrospinal fluid testing to establish a diagnosis. However, for those with significant increase in intracranial pressure, it is best to lower the intracranial pressure before performing lumbar puncture to prevent the occurrence of cerebral hernia after lumbar puncture.

Infants and children with irregular treatment often have atypical clinical manifestations, and the latter's cerebrospinal fluid changes may not be obvious. Etiological examinations are often negative. The diagnosis should be carefully asked for medical history and detailed physical examination, combined with specific immunological examinations of pathogens in cerebrospinal fluid and The condition changed after treatment, and the diagnosis was established after comprehensive analysis.

Differential diagnosis of suppurative meningitis in children

In addition to pyogenic bacteria, tuberculosis bacteria, viruses, fungi, etc. can cause meningitis, and there are some clinical manifestations similar to those of cerebrum, which requires attention to identification. Cerebrospinal fluid examination, especially etiological examination, is the key to differential diagnosis.

1. Tuberculous meningitis needs to be differentiated from the irregularly treated brain. The nodule had a subacute onset, and meningeal irritation, convulsions, or disturbances of consciousness appeared only after 1 to 2 weeks of irregular fever, or cranial nerve or limb paralysis occurred before coma. Patients with a history of tuberculosis exposure, PPD positive, or tuberculosis in other parts of the lung support the diagnosis of tuberculous meningitis. The appearance of cerebrospinal fluid is ground-glass-like, and the number of white blood cells is more than 500 × 106 / L. The classification is mainly lymphocytes. The acid smear of thin film smears and the culture of tuberculosis bacteria can help establish the diagnosis.

2. The clinical manifestations of viral meningitis are similar to those of Huanao. The infection and the symptoms of the nervous system are lighter than those of Huanao. The course of the disease is self-limited, and most of them do not exceed 2 weeks. Cerebrospinal fluid is clear, white blood cell count is 0 to several hundred × 10 / L, lymph is predominant, and sugar content is normal. Isolation of specific antibodies and viruses in cerebrospinal fluid helps diagnosis.

3. The clinical and cerebrospinal fluid changes of cryptococcal meningitis are similar to those of tuberculous meningitis, but the disease progression may be slower, and the increase in cranial pressure such as headache is more persistent and severe. Diagnosis is based on cerebrospinal fluid smear ink staining and culture to find pathogenic fungi.

Treatment of pyogenic meningitis in children

Antibiotic treatment

(1) The principle of medication is to make the prognosis of the brain serious. Strive to kill the pathogenic bacteria in the cerebrospinal fluid within 24 hours of medication. Therefore, drugs that are sensitive to pathogenic bacteria and can pass through the blood-brain barrier should be selected. In the acute phase, intravenous medication should be used so that the medication is early, sufficient in dosage and sufficient in duration.

(2) The choice of antibiotics before the pathogens are identified includes those whose diagnosis has been initially established but the pathogens have not been identified, or irregular treatment outside the hospital. Antibiotics that are effective against three common pathogenic bacteria, Streptococcus pneumoniae, Meningococcus, and Haemophilus influenzae, should be selected. At present, the third-generation cephalosporins, including cefotaxime or ceftriazine, which can quickly reach an effective sterilization concentration in the cerebrospinal fluid of patients are mainly selected. Vancomycin can be used in combination when the effect is not satisfactory. Children with allergies to -lactam drugs can use chloramphenicol.

(3) Selection of antibiotics after the pathogens have been identified Streptococcus pneumoniae Since more than half of the current pneumococci are resistant to penicillin, the drugs should be selected according to the above-mentioned pathogens without a clear plan. Penicillin can be used only if the drug sensitivity test indicates that the pathogen is sensitive to penicillin. Meningococcus is different from Streptococcus pneumoniae. At present, most of the bacteria are still sensitive to penicillin, so they are selected first, with the same dose as before. A few people who are resistant to penicillin need to use the third-generation cephalosporins. Haemophilus influenzae can be replaced with ampicillin for sensitive strains. Drug-resistant individuals use the third-generation cephalosporins combined with meropenem, or chloramphenicol. If the other pathogenic bacteria is Staphylococcus aureus, nafcillin, vancomycin or rifampicin should be selected according to the drug sensitivity test. In addition to the third-generation cephalosporins, gram-negative bacilli can be added with ampicillin or meropenem.

(4) The course of antibiotics for Streptococcus pneumoniae and Haemophilus influenzae meningitis. The course of antibiotics should be intravenous drip of effective antibiotics for 10 to 14 days, meningococci for 7 days, Staphylococcus aureus and Gram-negative meningitis Should be more than 21 days. If there are complications, they should be extended appropriately.

2. Application of adrenocortical hormone

Adrenal corticosteroids not only inhibit the production of a variety of inflammatory factors, but also reduce vascular permeability and reduce cerebral edema and intracranial hypertension. Dexamethasone is commonly used for 2 to 3 days in a row. It is not beneficial to use it for too long. Dexamethasone must be used at the same time as the first dose of antibiotics. Unconventional application of corticosteroids to newborns.

3. Treatment of complications

(1) A small amount of effusion in subdural fluid need not be treated. If the volume of fluid is large and causes symptoms of increased intracranial pressure, a subdural puncture should be performed to release the fluid, and the volume of fluid should not exceed 15ml per side each time. Some children need to be punctured repeatedly, and most of them are gradually reduced and cured. Individuals who do not heal need surgical drainage.

(2) Ventriculoperitonitis is performed with lateral ventricular puncture and drainage to relieve symptoms. At the same time, in view of the pathogenic bacteria and the safety of medication, the appropriate intraventricular injection of antibiotics was selected.

(3) Hydrocephalus mainly depends on surgical treatment, including median mesopoor adhesion release, aqueduct dilation, and cerebrospinal fluid shunt surgery.

4. Symptomatic and supportive treatment

(1) Tightly monitor vital signs during the acute phase, regularly observe changes in children's consciousness, pupils, and respiratory rhythm, and deal with intracranial hypertension in time to prevent the occurrence of cerebral hernia.

(2) Control seizures in time and prevent recurrence. Diazepam, advantages: rapid effect (effective within 1 to 3 minutes), effective on 85% to 90% of attacks, disadvantages: short-term maintenance effect (1/2 to 1 hour), specific constitution can inhibit breathing. 10% chloral hydrate retention enema can be used interchangeably with diazepam. Sodium phenobarbital (lumina), intramuscular injection or intravenous drip, intramuscular injection for 20-30 minutes, intravenous injection for 5 to 10 minutes are effective. Diazepam + phenobarbital sodium: pay attention to respiratory depression. Others: Laurazepam, clonazepam, phenytoin, sodium valproate.

(3) Monitor and maintain water, electrolyte, plasma osmotic pressure and acid-base balance in the body. For those with abnormal antidiuretic hormone secretion syndrome, actively control meningitis, and appropriately limit the amount of fluid, and supplement sodium salt as appropriate for those with severe symptoms of low sodium.

Prognosis of pyogenic meningitis in children

The infant mortality rate is 10%. Pneumococcal meningitis and children aged 4 days had a higher mortality rate. 10% to 20% of survivors have severe neurological sequelae. Common neurological sequelae include hearing loss, mental retardation, epilepsy, delayed language ability, visual impairment, and behavioral abnormalities.