A Simple Guide to Meningitis

A Simple Guide to Meningitis
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What is Meningitis?
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Meningitis is a serious medical disease which causes inflammation and infection of the meninges which are the protective lining of the spinal cord and brain.

What are the causes of Meningitis?
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The causes of Meningitis may be divided into:

Infections:
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1.viral infections are the most common and are usually mild
(enterovirus, herpes simplex virus 2 and mumps) except for Hand mouth and foot disease(enterovirus EV7)which can cause fatality in children

2.bacterial infections such as meningoccocus (Neisseria meningitidis) and pneumococcus (Streptococcus pneumoniae) can be serious and fatal in some cases.

Meningococcal meningitis can cause outbreaks(spread easily).

E.coli, Group B streptococus and Pseudomonas infection are common in neonates.

Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae are common in infants and children

Streptococcus pneumoniae, N. meningitidis, Mycobacteria are more common in adults.

Mycobacterium tuberculosis meningitis are more common in developing countries and in people whose immune systems are impaired(eg. AIDS) and are preceded by active tuberculosis infections elsewhere.

3.fungi
Cryptococcus neoformans is the most common cause of fungal meningitis

Non-infectious:
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Non infectious causes usually irritates the meninges through inflammation and auto immune reactions:

1.cancers,

2.systemic lupus erythematosus

3.drugs.

4.head injury

5.post neurosurgical procedures


What are Signs and symptoms of Meningitis?
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The triad of symptoms which often defines meningitis are:

1.Severe headache

2.Neck rigidity (unable to flex the neck forward),
A positive Kernig's sign means that the neck will painful when one hip is flexed to 90 degrees and the knee flexed to 90 degrees in a patient lying supine.

3.vomiting

Other symptoms are:

4.high fever

5.mental confusion.

6.Malaise

7.photo-phobia (inability to tolerate bright light),

8.phono-phobia (inability to tolerate loud noises),

9.irritability especially in small children

10.seizures .

11.swelling of the fontanelle may be present in infants

12.rash with numerous small, irregular red spots on the body, lower legs, soles of feet, palms

13.ulcers of the mouth (present in hand,mouth and foot disease).

How is the diagnosis of Meningitis made?
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1.Classical symptoms and signs as above especially neck rigidity

2.blood tests (complete blood count, ESR and blood culture)

3.X-rays of chest and brain

4.cerebrospinal fluid (CSF) analysis via lumbar puncture is examined for white blood cells, red blood cells, protein content, glucose level and micro-organisms.

This test should not be done if there is suspected cerebral mass lesion or raised intracranial pressure (head injury, localizing neurological signs)

A pressure of over 180 mm suggests bacterial meningitis.

5.CSF glucose is low,protein high and cells high in bacterial meningitis,
CSF glucose is normal,protein normal and cells high in viral meningitis
CSF glucose is low,protein high and cells high in fungal meningitis

6.CT or MRI of the brain and spine with MRI preferred over CT because it can detect more easily areas of cerebral edema,tumors, ischemia, and meningeal inflammation.

What are the complications of Meningitis?
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1.Neurological deficits

2.deafness

3.learning disorders in children

4.brain infarction,

5.septic shock,

6.adult respiratory distress syndrome

7.seizures also more in children

8.pneumonia especially in the elderly

What is the treatment of Meningitis?
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1.Hospitalization should be immediate as meningitis is an life threatening condition.

2.Antibiotics such as cephalosporin, ampicillin, chloramphenicol, intravenous vancomycin to be started even before doing lumbar puncture.

Acyclovir may be given for herpes virus infection

High dosages of anti-fungals may be given for Fungal meningitis for a prolonged period of time

3.corticosteroids is useful to reduce complications

4.High-flow oxygen

5.intravenous fluids

What is the prognosis of Meningitis?
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This depends on the severity and type of infection.

Viral infections except for enterovirus EV7 usually recover quickly.

Bacterial infections such as meningococcus and pneumococcus are more dangerous.

What are the Preventive measures taken for Meningitis?
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Vaccinations against Haemophilus influenzae in children and adults has reduced the incidence of this form of meningitis.

Vaccines against type A and C Neisseria meningitidis are used to prevent these types of meningitis especially in those who travel abroad.

Vaccines against type B Neisseria meningitidis have yet to be produced athough a drug company is doing research on the production of this vaccine.

Pneumococcal vaccine against Streptococcus pneumoniae has been given to newborns to prevent pneumococcal meningitis.

Mumps vaccination as part of Measles, mumps and rubella vaccine(MMR) has reduced the incidence of mumps related form of meningitis