Meningitis​: Causes, Diagnosis, Sign, Prevention & Treatment

Advertisement

Meningitis is an inflammation of the lining around the brain and spinal cord called meninges caused by bacteria, viruses or fungi. Meningitis can be the primary reason a patient is hospitalized or can develop during hospitalization and is classified as septic and aseptic. Septic meningitis is caused by bacteria, whereas in aseptic Meningitis, the cause is viral or secondary to leukaemia, lymphoma or autoimmune diseases like human immunodeficiency virus (HIV) and systemic lupus erythematosus (SLE). The other type of meningitis is tuberculous meningitis.

Causing factors of Meningitis

The bacteria Streptococcus pneumonia and Neisseria meningitides are responsible for almost 80% of all the cases of meningitis in adults.

Advertisement

Haemophilus influenzae was once a common cause of Meningitis in children. However, currently because of the vaccination the infection due to this organism is now under control and are rare in developed countries.

The outbreak of infection is most likely to occur in dense population, groups, and community. The predisposing factors for the increase in the risk of bacterial meningitis include the use of tobacco and upper respiratory infection because they increase the amount of droplet production. People with immune system deficiencies are also at greater risk for getting bacterial Meningitis .

Advertisement

Pathophysiology

Bacterial meningitis is a pyogenic infection which involves the pia-arachnoid layer of the meninges including Cerebrospinal fluid. The inflammation spreads by means of purulent exude through Cerebrospinal fluid circulation.

Initially, when bacteria involves the pia-arachnoid and subarachnoid spaces, there is a rapid increase in blood supply to the involved area. Neutrophils soon migrate into the subarachnoid space in massive numbers and engulf the bacteria. These phagocytic cells rapidly degenerate and disintegrate, which then combines with the exudate formed from tissue destruction. This forms purulent material within the subarachnoid space and exudate extending particularly over the base of the brain.

Advertisement

Signs and symptoms

Most of the signs and symptoms are shared by all types of meningitis due to the inflammation of meninges causing increased intracranial pressure.

  • A headache and fever are frequently the initial symptoms
  • Rigidity, stiffness and painful neck is the early sign of Meningeal irritation
  •  Photophobia (extreme sensitivity to light)
  •  Alteration in the level of consciousness, lethargy and coma may develop later
  •  Skin lesions develop ranging from petechial rash with purpuric lesions to large areas of ecchymosis
  •  Seizures can occur and are the result of areas of irritability in the brain
  •  Septic shock
  •  Signs of increased intracranial pressure such as:
    ● Vomiting
    ● Weak bradycardia
    ● Respiratory difficulties
    ● Pupillary dilation or constriction
    ● Papilloedema
  • Hydrocephalus may develop later
  • Death may occur if left untreated.

How do we diagnose Meningitis?

If the clinical features (sign and symptoms) suggests Meningitis, diagnostic-testing is conducted to identify the causative organism. The diagnosis of meningitis is based upon:
▪ History and Neurological examination of the patient
▪ Lumbar puncture is common for the analysis of CSF (Cerebrospinal fluid) for bacterial culture, gram staining, level of glucose, protein levels and white blood cells count.
▪ CT scan and MRI are done to detect a shift in the brain contents (which may lead to herniation) prior to lumbar puncture.
▪ Laboratory data includes haematology and biochemistry.

Prevention

  • Adequate treatment of infection such as sinusitis, mastoiditis and ear infection which can be secondary Cause of meningitis.
  • Maintain healthy living standard and hygiene
  • Vaccination should be considered for as an adjunct to chemoprophylaxis who is in contact or living with the same person who develops a meningococcal infection.
  • Use of strict aseptic technique during all intracranial operations and in changing the dressing.
  • Prophylactic antibiotics after head injury.

Complications of meningitis

  1. Visual impairment
  2. Optic neuritis
  3.  Deafness
  4.  Personality changes
  5.  Seizure activity
  6.  Hydrocephalus
  7.  Pneumonia

Treatment

A successful outcome depends on the early administration of antibiotics that crosses the blood-brain barrier into the Subarachnoid space in sufficient concentration to half the multiplication of barrier. Antibacterial therapy requires the selection of the drug most effective against the including organism. Dosage will depend upon the age of the patient. Vancomycin hydrochloride in combination with cephalosporin is administered intravenously. Other antibiotics such as penicillin, chloramphenicol, ampicillin, cloxacillin, gentamycin. Dexamethasone has been shown to be beneficial as adjunct therapy in the treatment of
acute bacterial meningitis in pneumococcal meningitis. Dehydration and shock are treated with fluid volume expander. A seizure is controlled with phenytoin. General supportive measures include maintaining adequate ventilation and a patent airway, establishing fluid and electrolyte balance instituting hypothermia management and controlling headache seizures.

Rehabilitation
The specific rehabilitation needs of the patient depend upon the degree of disability resulting from meningitis. Minor disabilities may not require any intervention as they will reverse themselves with time. Others require an aggressive rehabilitation plan.

Isolation to the patient to prevent the disease from spreading depends upon the type of invading organism because it is possible to infect other with secretions from the nasopharynx and droplets from the respiratory tract.

Healthcare provider (Doctors, Nurses, Assistant ) should care the patient under the precaution.

Advertisement

 

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.