Overview
Pneumococcal meningitis is a disseminated disease that occurs in winter and spring, and is more common in infants and young children, and in elderly or chronically ill patients, but is not uncommon in adults. It is often secondary to pneumonia or pneumococcal sepsis, followed by otitis media, mastoiditis, sinusitis and other foci of infection, and in some patients secondary to cranio-cerebral trauma, fracture or brain surgery, and in a few cases there is no clear primary lesion.
Etiology
In cases where the primary focus is pneumonia, the germs reach the meninges from the blood circulation. In otitis media, the organisms may invade through the osseous laminar scales destroyed by inflammation and through blood vessels communicating with the meningeal vessels, and may also extend to the meninges through the internal auditory canal and the endolymphatic vessels. The germs of sieve sinusitis, on the other hand, may infect the meninges through nerve sheaths or thrombophlebitis. Bacteria from the nose of patients with cerebrospinal fluid nasal leakage can travel upward to infect the meninges. Bacteria from craniocerebral trauma can invade the meninges directly from the trauma site. Infants with congenital malformations, such as cerebrospinal bulge, meningeal dermatomal sinus tract, vertebral malformation, etc., germs can invade the meninges and cause disease.
Pathogenic bacteria invade the meninges and cause capillary dilatation in the brain, congestion, increased permeability, producing a large number of fibrin and other inflammatory exudates, and can quickly cause adhesions and encapsulated pus, and even subdural fluid or pus. When the course of the disease is long, obstruction of cerebrospinal fluid circulation in the ventricular system, dilatation of the ventricles and even hydrocephalus or pus accumulation in the ventricles may occur, thus secondary to increased intracranial pressure, causing aphasia, hemiparesis and other sequelae.
Symptoms
Pneumococcal meningitis secondary to various pneumococcal pneumonias, with the vast majority occurring within 1 week of onset and a few more than 10 days. The interval between otitis media, sieve sinusitis and meningitis is about 1 week; the interval between meningitis and craniocerebral injury is more than 1 month.
The onset of the disease is rapid, with high fever, headache, vomiting, and the occurrence of consciousness disorders, which are manifested as delirium, lethargy, lethargy, coma, and so on. Cerebral nerve damage accounts for about 50% of the cases, mainly involving the motor and facial nerves, and the synovial and abducens nerves may also be involved. Skin petechiae are rare. Intracranial hypertension and signs of meningeal irritation are similar to those of other purulent meningitis.
Pneumococcal meningitis is one of the pneumococcal infectious diseases. The inter-episode period is months or years. The causes of recurrent attacks are:
1. Nasal leakage of cerebrospinal fluid;
2. congenital
Defects others such as congenital sieve plate cleft, congenital dermatomal sinus tract, meningeal or spinal membrane bulge other or acquired cranial injury;
3. presence of parietal meningeal infectious lesions such as chronic mastoiditis or sinusitis;
4. post-splenectomy in children;
5. Immune deficiency
such as congenital immunoglobulin deficiency, application of immunosuppressive drugs;
6. extreme cerebrospinal fluid, which tends to form adhesions and purulent packages, affecting the efficacy of drugs.
7. Infant patients are more
Usually present with convulsions, lethargy, extreme irritability, anorexia, projectile vomiting, sensory hypersensitivity, sudden screaming, double vision, convulsions are far more frequent than in adults, and may be angular: physical examination may reveal full fontanel per, but not obvious if dehydration is present.
Examination
The peripheral blood picture shows a marked increase in the total number of leukocytes, with 10×109/L in 94% of cases, half of which are >20×109/L, and the majority of neutrophils are above 95%. Cerebrospinal fluid was purulent, sometimes containing lumps, with increased cell count and protein content, and decreased sugar and chloride. In advanced cases, there are protein and cell separation phenomenon, which is caused by the obstruction of the spinal canal, then it is appropriate to make a puncture of the cerebellar medulla oblongata pool, and a large number of pus cells can be seen in the cerebrospinal fluid that is drained. The chance of finding gram-positive diplococci in the smear is higher other up to 87.6% other, and the culture is often positive.
Convection immunoelectrophoresis has been applied to clinical, pneumococcal meningitis patients positive rate of up to 79%; latex agglutination test positive rate of 80%, in the treatment of 1 / 3 ~ 1/2 positive. The lactate dehydrogenase activity of cerebrospinal fluid in pneumococcal meningitis can be significantly elevated.
Anyone who develops high fever, altered mental status, intracranial hypertension and signs of meningeal irritation following pneumonia, otitis media, sinusitis and craniocerebral trauma should consider the possibility of pneumococcal meningitis, and examine the cerebrospinal fluid as early as possible to make a clear diagnosis. Meningitis occurring in winter and spring without the above triggers and without petechiae on the skin should also be considered as a possible cause of the disease.
Diagnosis
Diagnosis can be made on the basis of medical history, clinical manifestations, combined with blood counts, cerebrospinal fluid examination, and bacteriologic examination.
1. history of pneumonia, otitis media, mastoiditis, sinusitis, etc.
2. Clinical manifestations start sharply with high fever, headache, vomiting, and impaired consciousness, which manifests as irritability, delirium, or coma. Infants often present with fever, projectile vomiting, convulsions, lethargy, irritability, sudden screaming, and full fontanel.
3. The disease often recurs in multiple episodes, with intervals of months or years between episodes.
4. Auxiliary examination
(1) Blood routine: increased white blood cell count, increased proportion of neutrophils.
(2) Cerebrospinal fluid examination: purulent changes, cell count mostly in (500-2000) × 106 / L, neutral multinucleated cells accounted for more than 80%, protein content increased, sugar and chloride content decreased.
(3) Bacteriologic examination: pneumococcus can be detected in cerebrospinal fluid smear, and cerebrospinal fluid or blood culture is positive in some patients.
Differential diagnosis
This disease should be differentiated from meningococcal, rheumatoid bacillus, aureus, Escherichia coli, Pseudomonas aeruginosa and other purulent meningitis. If the cerebrospinal fluid is atypical in appearance and cell count, it should be differentiated from tuberculous meningitis and brain abscess.
Complications
Due to the high content of fibrin in the exudate, it is easy to cause adhesion, or due to late diagnosis and improper treatment, it may be complicated by subdural effusion or pus, hydrocephalus, brain abscess, and cerebral nerve damage. Nociceptive disorder, hemiparesis, deafness, ataxia, and postmeningitis epilepsy are also seen.
Treatment
Penicillin is the drug of choice, and a high dose of IV is appropriate. After symptoms improve and cerebrospinal fluid is near normal, adults continue the medication until temperature and cerebrospinal fluid are normal, and the course of treatment should not be less than 2 weeks. Intrathecal administration of penicillin may incur adverse reactions such as convulsions, fever, subarachnoid adhesions, myelitis and radiculitis, so it is not suitable.
Allergy to penicillin can be changed to chloramphenicol with the same dosage as rheumatoid, but close attention should be paid to inhibit the toxic reaction of bone marrow. Erythromycin can also be applied IV. Cefotaxime, ceftriaxone IV can also achieve good results. Primary lesions such as otitis media, mastoiditis, sieve sinusitis, etc. need to be treated at the same time to prevent recurrence of the disease.