disese of the brain

2. The brain and spinal cord are covered by 3 connective tissue layers collectively
called the meninges which form the blood-brain barrier.
Definition:
 the pia mater (closest to the CNS)
 the arachnoid mater
 the dura mater (farthest from the CNS).
The meninges contain cerebrospinal fluid (CSF).
Meningitis is an inflammation of the
meninges, which, if severe, may become
encephalitis, an inflammation of the brain.

3. Meningitis……
Definition
Meningitis is an infection which causes
inflammation of the membranes
covering the brain and spinal cord.
Non-bacterial meningitis is often referred to
as ‘aseptic meningitis’ – eg. viral
meningitis
Bacterial meningitis may be referred to as
‘purulent meningitis’.
Causes and risks
The most common causes of meningitis are viral infections that usually
resolve without treatment.
Bacterial infections of the meninges are extremely serious illnesses, and
may result in death or brain damage even if treated.

4. Mood of Spread
• Microorganisms reach the meninges either by direct
extension from the ears, Nasopharynx, cranial
injury or congenital meningeal defect, or by
bloodstream spread.
• Non-infectious causes of inflammation include
malignant cells, drugs and blood following
subarachnoid haemorrhage.

5. Classification
1. Acute pyogenic (bacterial) meningitis
2. Acute aseptic (viral) meningitis
3. Acute focal suppurative infection (brain abssces,
subdural and extradural empyema)
4. Chronic bacterial infection (tuberculosis).

6. Causes of Meningitis
Bacterial Infections
Viral Infections
Fungal Infections
(Cryptococcus neoformans
Coccidiodes immitus)
Inflammatory diseases
(SLE)
Cancer
Trauma to head or spine.

7. INFECTIVE CAUSES OF MENINGITIS
Bacteria
• Neisseria meningitidis*
• Streptococcus pneumoniae*
• Staphylococcus aureus
• Streptococcus Group B
• Listeria monocytogenes
• Gram-negative bacilli ( E.Coli)
• Mycobacterium tuberculosis
• Treponema pallidum
Viruses
• Enteroviruses:
• Coxsackie
• Mumps
• Herpes simplex
• HIV
• Epstein-Barr virus
Fungi
• Cryptococcus neoformans
• Candida
• (Coccidioides immitis, Histoplasma capsulatum, Blastomyces dermatitidis)

8. Bacterial meningitis…..
Etiological Agents:
-Pneumococcal, Streptococcus pneumoniae (38%)
-Meningococcal, Neisseria meningitidis (14%)
-Haemophilus influenzae (4%)
-Staphylococcal, Staphylococcus aureus (5%)
-Tuberculous, Mycobacterium tuberculosis (3%)

9. Acute pyogenic bacterial meningitis
• Most important
• Can be fatal if untreated
• Organisms:
E.coli ---------- neonates
Streptococci B ---------- neonantes
H. influenzae-------------adolescents
Neisseria meningitidis------------- young adults
Streptococcus pneumonia--------- elderly

10. Bacterial Meningitis
 Potentially life threatening disease.
 One million cases per year world wide.
 200,000 die annually.
 Can affect all age groups but some are at higher risk.
 Treatment available : antibiotics as per causative organism
 Humans are the reservoir .
 Pneumococcal meningitis is the most common type. Approximately
6,000 cases/yr
 Haemophilus meningitis: Since 1985 Incidence has declined by 95%
due to the introduction of Haemophilus influenza b vaccine.
 Other bacterial meningitis caused by E-Coli K-1, Klebsiella species and
Enterobacter species are less common overall, but may be more
prevalent in newborns, pregnant women, the elderly and
immunocompromised hosts.

11. Meningococcal Meningitis
Nationally notifiable disease
Etiological Agent: Neisseria meningitidis
Clinical Features: sudden onset. F,H,N,V
Reservoir: Humans only. 5-15% healthy carriers
Mode of transmission: direct contact with patients oral or
nasal secretions. Saliva.
Incubation period: 1-10 days. Usually 2-4 days
Infectious period: as long as meningococci are present in oral secretions
or until 24 hrs of effective antibiotic therapy
.
Petichial Rash

12. Aseptic Meningitis
Definition: A syndrome characterized by acute onset of meningeal
symptoms, fever, and cerebrospinal fluid pleocytosis, with
bacteriologically sterile cultures.
Laboratory criteria for diagnosis:
CSF showing ≥ 5 WBC/cu mm
No evidence of bacterial or fungal meningitis.
Case classification
Confirmed: a clinically compatible illness diagnosed by a physician
as aseptic meningitis, with no laboratory evidence of bacterial or
fungal meningitis
Comment
Aseptic meningitis is a syndrome of multiple etiologies, but most
cases are caused by a viral agent.

13. Acute Aseptic (Viral ) Meningitis
• Can follow any viral infection
• Less danger
• CSF shows :
1.lymphocytes
2. mild increase in protein
3. normal glucose level
Viral meningitis is usually self-limiting and treated
symptomatically.

14. Viral Meningitis
 Etiological Agents:
 Enteroviruses (Coxsackie's and echovirus): most common.
 Adenovirus
 Arbovirus
 Measles virus
 Herpes Simplex Virus
 Varicella Zoster ( Chicken pox)
 Reservoirs:
 Humans for Enteroviruses, Adenovirus, Measles, Herpes Simplex, and
Varicella
 Natural reservoir for arbovirus birds, rodents etc.
 Modes of transmission:
 Primarily person to person and arthopod vectors for Arboviruses
 Incubation Period:
 Variable. For enteroviruses 3-6 days, for arboviruses 2-15 days
 Treatment: No specific treatment available.
Most patients recover completely on their own.

15. CNS Tuberculosis:
A meningeal pattern of spread can occur, and
the cerebrospinal fluid (CSF) typically shows a
high protein, low glucose, and lymphocytosis.

16. The base of the brain is often involved, so
that various cranial nerve signs may be
present.
Rarely, a solitary granuloma, or
"tuberculoma", may form and manifest with
seizures.

17. Symptoms of meningitis….
Adults and children
Babies
Neonates and the elderly often present atypically .

19. CLINICAL FEATURES
The meningitic syndrome
• This is a simple triad: headache, neck stiffness
and fever.
• Photophobia and vomiting are often present.
• In acute bacterial infection there is usually
intense malaise, fever, rigors, severe headache,
photophobia and vomiting.
• This develops within hours or minutes.
• Neck stiffness and positive Kernig's sign usually
appear within hours.

20. • In less severe cases (e.g. many viral meningitides)
there are less prominent meningitic signs, but fatal
bacterial infection may also be indolent, with a
deceptively mild onset.
• In uncomplicated meningitis, consciousness
remains intact, although anyone with high fever
may be delirious.

21. Symptoms:
One of the physically demonstrable symptoms of meningitis is Kernig's sign.
Kernig's sign: Severe stiffness of the hamstrings causes an inability to straighten the leg
when the hip is flexed to 90 degrees.

22. Symptoms:
Another physically demonstrable symptoms of meningitis is Brudzinski's
sign.
Brudzinski's sign: Severe neck stiffness causes a patient's hips and knees to flex when
the neck is flexed.

23. In the early stages, signs and symptoms can be similar to
many other more common illnesses, for example flu.
Early symptoms can include fever, headache, nausea
(feeling sick), vomiting and general tiredness.
The common signs and symptoms of meningitis and
septicemia are shown above.
Others can include rapid breathing, diarrhea and stomach
cramps. In babies, check if the soft spot (fontanelle) on the
top of the head is tense or bulging.

25. • Complications include: cerebral edema, venous
sinus thrombosis, brain abscess , septicemia, DIC
and multi-organ failure (MOFS)

26. SPECIFIC VARIETIES OF MENINGITIS
Acute bacterial meningitis
• Onset is typically sudden, with rigors and high fever.
Meningococcal meningitis is often associated by a
petechial or other rash. The meningitis may be part of
a generalized meningococcal septicaemia. Acute
septicaemic shock may develop in any bacterial
meningitis.
Viral meningitis
• This is almost always a benign, self-limiting condition
lasting 4-10 days. Headache may follow for some
months. There are no serious sequelae.
Chronic meningitis

27. MENINGITIS
Differential diagnosis
• It may be difficult to distinguish between the sudden
headache of subarachnoid haemorrhage, migraine and
acute meningitis.
• Meningitis should be considered seriously in anyone
with headache and fever and in any sudden headache.
Neck stiffness should be assessed carefully - it may not
be obvious.
• Chronic meningitis sometimes resembles an
intracranial mass lesion, with headache, epilepsy and
focal signs.
• Cerebral malaria often mimics bacterial meningitis.

28. Clinical differences in meningitis
Clinical feature Probable cause
Petechial rash Meningococcal infection
Skull fracture
Pneumococcal infection
Ear disease
Congenital CNS lesion
Immunocompromised patients HIV opportunistic infection
Rash or pleuritic pain Enterovirus infection
International travel Poliomyelitis
Malaria
Occupational history (working in drains,
anals, polluted water, ecreational
swimming): rostration, myalgia,
onjunctivitis, jaundice
Leptospirosis

29. INVESTIGATIONS
• On arrival in hospital, routine tests including blood
cultures should be carried out immediately, and a
close lookout kept for the emergence of
septicaemic shock.
• lumbar puncture is performed if there is no clinical
suspicion of a mass lesion.
• If the latter is suspected an immediate CT scan must
be performed because coning of the cerebellar
tonsils may follow.

30. Diagnostic test for meningitis :
lumbar puncture….
A lumbar puncture collects
cerebrospinal fluid to check for the
presence of disease or injury.
A spinal needle is inserted, usually
between the 3rd and 4th lumbar
vertebrae in the lower spine.
Permits the urgent distinction of bacterial meningitis
from viral meningitis and examination of the CSF allows
precise diagnosis.

31. Typical CSF findings in Meningitis
Bacterial meningitis
1. Presence of neutrophils in the
CSF is associated with infection
by N. meningitidis, S.
pneumoniae etc.
2. CSF protein level reflects the
degree of meningeal
inflammation:-
10 X in bacterial infections
3. CSF glucose levels :-
very low in bacterial infections
Viral meningitis
1. Presence of lymphocytes is
associated with infection by
viruses or mycobacteria.
2. CSF protein level reflects the
degree of meningeal
inflammation:-
2-3 X in viral CNS infection
3. CSF glucose levels :-
normal with viral infections

32. CSF in meningitis
Normal Viral Pyogenic Tuberculosis
Appearance Crystal-clear Clear/turbid Turbid/purulen
t
Turbid/viscous
Mononuclear
cells
< 5 mm3 10-100 mm3 < 50 mm3 100-300 mm3
Polymorph
cells
Nil Nil* 200-300/mm3 0-200/mm3
Protein 0.2-0.4 g/L 0.4-0.8 g/L 0.5-2.0 g/L 0.5-3.0 g/L
Glucose ⅔ > ½ blood
glucose
> ½ blood
glucose
< ½ blood
glucose
< ½ blood
glucose

33. INVESTIGATIONS
• In Somalia lumbar puncture not available so that we
request only :
 CBC
 ESR
 Malaria

34. MANAGEMENT
• Recognition and immediate treatment of acute bacterial
meningitis is vital. Minutes save lives.
• Bacterial meningitis is lethal.
• Even with optimal care, mortality is around 15%.
• The immediate management of suspected meningococcal
infection is benzylpenicillin 1200 mg (adult dose) either by
slow i.v. injection or intramuscularly, prior to investigations.
• Cefotaxime 1 g i.v. is an alternative in cases of penicillin
allergy.
• In meningitis, minutes count: delay is unacceptable.

35. Managements & Guidelines in
Pediatrics
A. Bacterial Meningitis:
• Dexamethasone injection for 2-3 Weeks To Reduce Inflammation and to
prevent Increase Intracranial Pressure(ICP).
• Ampicillin Injection for 7 to 14 days & Cefatriaxone Injection for 14 days To
Prevent Septicemia and Complication.
• Diazepam Injection 10mg 0.3mg/kg every convulsion to prevent Brain
Damage.
• Phenobarbital tab 30mg at Night 1-2mg/kg If convulsion > 2 times per day.
• Ibuprofen tab Or Syrup For Inflammation
•

36. Managements & Guidelines
B. Viral Meningitis:
• Acyclovir 200mg 20-30mg/kg for 4-6times per day for 7 days.
• Supportive Treatments.

37. Managements & Guidelines
B. Tubercular ( TB ) Meningitis:
• HRZE tab ¼ tab < 10kg ½ tab 10-14kg 1 tab 15-19kg for first 3
months
• Streptomycin Injection 1g 15mg/kg times water for injection 5cc for first 2
months
• Prednisolone tab 5mg 2mg/kg, divide at morning & afternoon for first 1
month

38. PROPHYLAXIS
• Meningococcal infection should be notified to public health
authorities, and advice sought about immunization and prophylaxis
of contacts, e.g. with rifampicin or ciprofloxacin.
• MenC, a meningococcal C conjugate vaccine, is part of childhood UK
immunization and often given to case contacts.
• A combined A and C meningococcal vaccine is sometimes used
prior to travel to endemic regions, e.g. Africa, Asia; and a
quadrivalent ACWY vaccine for specific events, e.g. Hajj and Umrah
in Mecca.
• There is no vaccine for Group B. A polyvalent pneumococcal vaccine
is used after recurrent meningitis, e.g. after a CSF leak following
skull fracture.
• Hib (Haemophilus influenzae) vaccine is given routinely in childhood
in the UK, virtually eliminating a common cause of fatal meningitis.

39. CHRONIC MENINGITIS
• Tuberculous meningitis (TBM) and cryptococcal
meningitis commence typically with vague headache,
lassitude, anorexia and vomiting.
• Acute meningitis can occur but is unusual.
• Meningitic signs usually take some weeks to develop.
• Drowsiness, focal signs (e.g. diplopia, papilloedema,
hemiparesis) and seizures are common. Syphilis,
sarcoidosis and Behçet's syndrome also cause chronic
meningitis. In some chronic meningitis an organism is
never identified.
• Treatment with anti-TB drugs - rifampicin, isoniazid and
pyrazinamide - must commence on a presumptive
basis and continue for at least 9 months.
• Ethambutol should be avoided because of its eye
complications.

40. Complications
• Antibiotic treatment------ full recovery
• Delayed or untreated cases--- can be fatal
• Healing by fibrosis cause obliteration of
subarachenoid space--- HYDROCEPHALUS
• Brain abscess
• Septic shock and skin rashes, why ?

41. Skin rashes
• Is due to small skin bleed
• All parts of the body are affeced
• The rashes do not fade under pressure
• Pathogenesis:
a. Septicemia
b. wide spread endothelial damage
c. activation of coagulation
d. thrombosis and platelets aggregation
e. reduction of platelets (cosumption )
f. BLEEDING 1.skin rashes
2.adrenal hemorrhage
Adrenal hemorrhage is called Waterhouse-Friderichsen
Syndrome.
It cause acute adrenal insufficiency and is uaually fatal

44. Brain abscess
• Causes :
1. complication of bacterial meningitis
2. bacterial endocarditis
3. pulmonary sepsis : peumonia……etc
4. other sepsis
Brain abscess cause a space occupying lesion in the brain
Other Complications

45. Complications & Outcome:
• Severe Handicap ~ 25-30%
– Hemiplegia
– Blindness
– Deafness
– Severe Learning Difficulty = Cerebral Palsy ( CP )
– Severe behavioural disturbances
– Severe Epilepsy.
– Developmental delay
• Death ~ 30%

46. 46
End
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