1. Bacterial Meningitis http://www.youtube.com/watch?v=PYoTQ9HG_cE

2. Meningitis
The word “meningitis” usually describes inflammation of the meninges owing to the infective agents.

3. Types of meningitis Acute pyogenic (usually bacterial meningitis),
Aseptic (usually acute viral meningitis), and
Chronic (usually tuberculosis, spirochetal, or cryptococcal)
The above classification is based on the characteristics of inflammatory exudate on CSF examination and the clinical evolution of the illness

4. Bacterial meningitis -is caused by any one of several bacteria.
-is the leading cause of acute confusional state and one of which early diagnosis greatly improves the outcome
-Primary causative agents
1. Haemophilus influenzae type b
2. Neisseria meningitidis or "meningococcus"
3. Streptococcus pneumoniae or "pneumococcus"

5. Secondary causative agents
Staphylococcus aureus
Sterptococcus group B
Listeria monocytogenes
Gram-negative bacilli
Mycobacterium tuberculosis
Treponema pallidum
Eischerichia coli

6. 50+ Age or condition Etiologic agents Less than 3 months S agalactiae
E coli
L monocytogenes
3 month -8 yrs
N meningitidis
S pneumoniae
H infuenzae
18-50 yrs
50+
Gram negative bacilli
Impaired cellular immunity
Head trauma, neurosurgery, or csf shunt
Staphylococci, gram –ve cocci and S pneumoniae

7. Three main routes by which microbes enter the nervous system
1. Hematogenous spread (most common means of entry)
2. Direct implantation (trauma, congenital malformations)
3. Local extension (otitis media and sinusitis)

8. Signs and Symptoms 2. neck stiffness
Physical examination shows:
1. fever
2. neck stiffness
3. thigh flexion upon flexion of the neck (Brudzinski’s sign)

9. 4.resistance to the passive extension of the knee with the hip flexed (kernig’s sign)
5. Vomiting, photophobia may be seen
6. Patients always like to lie still
7. petechial rashes is seen in 50-60% patients
8. Meningeal irritation is seen is 80% patients

10. Neurological examination shows:
1.Acute confusional state
2. Seizures and cranial nerve palsy
3. Coma in severe cases

11. Lab Diagnosis
-when meningococcal meningitis is diagnosed clinically by petechial rashes accompanied by other symptoms, immediate parenteral antibiotics should be given before any further investigations. (benzylpenicilin 1200 mg, alternative : cefotaxime)
-the causative organisms can be cultured from blood in 40-90% cases
-if there is any suspicion of the intracranial lesion, CT scan or MRI can be done

12. -Although these studies may be helpful, the most essential test in all suspected case is prompt lumbar puncture and CSF examination.
{in case of meningococcal meningitis, CSF is usually not performed since it may result cerebellar tonsils, so blood culture is main in this case}

13. CSF examination

14. CSF pressure is elevated in about 90% of the cases
Appearance of fluid ranges from slightly turbid to grossly purulent
WBC count 90,000 /mm3 consisting of chiefly polymorphonuclear leukocytes (predominantly in L monocytogenes meningitis)

15. -CSF glucose level is lower than half of normal blood glucose level
-CSF protein rises to g/L ( normal g/L)
-CSF glucose level is lower than half of normal blood glucose level
-Gram stained smears of CSF identify the causative organism is 80% cases.

16. Normal
Infected
Appearance
Crystal clear
Turbid/purulent
Mononuclear cells
<5 mm3
<50 mm3
Polymorph cells
Nil
/ mm3
protein
g/L
g/L
Glucose
2/3 of blood glucose
<1/2

17. Differential diagnosis
-it may be difficult to distinguish between the sudden headache of SAH, migraine and meningitis
-neck stiffness should be considered carefully
-cerebral malaria often mimics bacterial meningitis

18. Prevention
Children should be routinely immunized against H influenza by vaccination
N meningitidis vaccine is recommended for military recruits, college students and travelers to areas of ongoing epidemics

19. Treatment Organism Antibiotic Alternative (eg. allergy)
Unknown pyogenic
Cefotaxime( 50 g/kg intravenously every 6 hrs)
Benzylpenicilin or Chloramphenicol
Meningococcus
Benzylpenicilin
Cefotaxime
Pneumococcus
Penicillin
Haemophilus
Chloramphenicol

20. Nonpyogenic bacteria associated with aseptic meningitis
Mycobacterium tuberculosis
Leptospira
Treponema pallidum
Borrelia Nocardia
Bartonella
Atypical mycobacteria
Brucella

21. TUBERCULOUS MENINGITIS
Considered in patients who present with a confusional state specially if there is history of pulmonary tuberculosis, alcoholism, corticosteroid treatment, HIV infection or any other condition associated with impaired immune responses.
Patients usually have symptoms of headache, malaise, mental confusion, and vomiting

22. CSF findings
A moderate CSF pleocytosis made up of mononuclear cells or a mixture of polymorphonuclear and mononuclear cells
The protein level is elevated (strikingly), and
The glucose content is moderately reduced or normal

23. Neonatal Meningitis
Neonatal meningitis is inflammation of the meninges due to bacterial invasion in the 1st 90 days of life.
Neonatal meningitis occurs in 2/10,000 full-term and 2/1,000 low-birth-weight (LBW) neonates, with a male predominance

24. Etiology Primary causative agents(75%)
Group B streptococcus (—predominantly type III)
Escherichia coli (particularly those strains containing the K1 polysaccharide)
Listeria monocytogenes
Secondary causative agents
α-hemolytic streptococci
gram-negative enteric organisms (eg, Klebsiella sp, Enterobacter sp, Citrobacter diversus)
Haemophilus influenzae type b, Neisseria meningitidis, and Streptococcus pneumoniae

25. Symptoms