Meningitis

 Meningitis 

Inflammation of meninges covering brain and spinal cord.

Classification of meninges

1. Bacterial or pyogenic meninges

Meningococcu

Streptococcus

Pneumococcus

Haemophilus influenza

2. Aseptic meninges

Patients who have clinical/laboratory evidence for meningitis with negative routine bacterial cultures.

Bacteria, Virus, Fungi, Protozoa, Parasite 

3. Tubercular meninges

Tubercular meningitis caused by Mycobacterium tuberculosis.

Etiology of meninges

1. Bacteria 

Affect infant younger than 2 months- 

E.coli

Group B streptococci

B hemolytic streptococcus

Staphylococcus aureus

Affect infant above age of 3 months-

Haemophilus influenza 

Pneumococci

Meningococci

Virus 

Fungi 

Protozoa

Predisposing factors

1. Children on immunosuppressive drug

2. Diabetes mellitus and malignancies

3. Immunocompromised patients (babies with HIV positive mother)

4. Trauma, invasive procedures/lumber puncture

5. Infant young children; immune mechanism immature

Pathophysiology

Due to etiological factor

Organism invade surrounding blood vessels

Bacteria enters bloodstream

Inflammatory activation of endothelial cells.

Endothelial cell injury

Increased permeability of blood brain barrier (BBB)

Penetration of blood brain barrier 

Crosses blood brain barrier

Meningeal invasion

Proliferates in CSF (cerebrospinal fluid)

Inflammation of meninges

Increased ICP

Clinical features

Clinical features in neonates

Poor feeding

Vomiting

Lethargy

Seizures

Bulging or full fontanelle

Weak cry

Infants older than 3 months

Fever

Irritability

Poor feeling

Vomiting

High pitch cry

Seizures

Bulging fontanel

Nuchal rigidity; stiff neck

Clinical features in children older than 3 years

1. Fever/ chills/ malaise due to infection

2. Headache/vomiting; due to increased ICP

3. Sign of meningeal irritation

1. Nauchal rigidity; stiff neck

2. Positive Brudzinski's sign

Patient is in supine position

On passive flexion of neck

Involuntary bending of hip and knees on passive flexion of neck.

3. Positive kernig's sign

Patient lying with supine position and passive flexion of hip and knee

Hip flexed 90 degree but extension knee is painful and backpain.

4. Opisthotonus position

Spasm in which back and and extremities arch backward.

4. Photophobia

5. Diplopia

6. Delirium

7. Seizure

8. Coma may develop

In viral meningitis

1. Generalized myalgia; muscle pain

2. Pharyngitis

3. Maculopapular skin rashes

Diagnostic evaluation

1. Lumber puncture; shows elevated pressure 

2. CSF Examination; cloudy and milky, WBC count raised, protein level high and glucose level decrease mark below 30mg/dl.

3. CSF Culture - reveals infection 

4. Blood examination  

5. Blood culture

6. CT scan / MRI scan

Management

Treatment of meningitis include-

1. Specific treatment

Antibiotics - started with antibiotics on the basis of culture and sensitivity report to CSF.

Penicillin with third generation cephalosporins.

Vencomycin with third generation cephalosporins; if penicillin resistance suspected.

Ceftriaxone/ cefotaxine with aminoglycosides.

2. Symptomatic treatment

1. Seizure management

Anticonvulsant/antiepileptic/ antiseizure drug; Phenobarbiton 

Dilantin; Phenytoin

Diazepam

2. Management of increased intracranial pressure

Mannitol

Frusemide 

3. Fever and headache

Aspirin or acetaminophen

3. Supportive care

1. IV fluids

2. Monitoring Neurological status

3. Patient with septic shock required vasoactive drug such as epinephrine and dopamine

Complication

1. Subdural effusion

2. Cerebral infarction

3. Cranial nerve palsy 

4. Encephalitis

5. Endocarditis

6. Brain abscess

7. SIADH - Syndrome of inappropriate antidiuretic hormone

8. Hydrocephalus

Prevention

1. Routine immunization ; helpful in preventing meningitis

2. Vaccination against measles, mumps, polio, meningococcus and pneumococcus organisms, protect child form meningitis.

3. Three dose of Hib vaccine; given to child, to prevent occurance of meningitis.