Download 1._Encephalitis_&_Meningitis

Encephalitis
Dr.Ibrahim Khasraw Jaf
Department of Pediatrics
School of Medicine
Sulaymani University
Definition :-
It is inflammatory process of the brain
parenchyma , mainly caused by
special types of viruses , leading to
mortality and morbidity among
children due to cerebral dysfunction .
Classification :According to the onset ;
Acute: abrupt onset with rapidly developing
clinical features , e.g.: enteroviruse , herpes
simplex virus encephalitis .
Subacute: slower developing symptoms
within days to few weeks , e.g.: measles ,
HIV .
Chronic: develop over long period(months) ,
e.g.: S.S.P.E. , T.B. .
Classification (continue..) :According to anatomical site of involvement ;
Focal: when one or more points of the brain
lobes involved like , temporal , parietal
lobes of the brain , limbic system .
Diffuse: (generalized) when whole brain
tissues involved .
Classification (continue..) :According to pathological process ;
Direct: when the infective agent itself invade
the brain and induce inflammation .
Indirect (post infectious) : when the infectious
agent , after cure induce immune mediated
inflammatory reaction in the brain due to
antibody-antigen reaction , e.g.: post ,
chickenpox crebellitis .
Etiology :Viral : includes these viruses according to the
incidence .
Enteroviruses : about 50% of cases due to
these groups of viruses , e.g.: coxachi &
echo viruses (non polio viruses) .
Herpes virus group : about 10-20% of cases
(herpes simplex virus , Epstein-Barr virus ,
cytomegalovirus , varicella zoster virus ,
human herpes viruse 6,7 ) .
Etiology (continue..) :Other viruses : may be caused by viruses
which cause systemic diseases rarely as a
part of complication they cause encephalitis
like influenza virus , measles , mumps ,
rubella (german measles) , rabies , HIV .
Nonviral causes : (mainly bacteria) : like
mycoplasma , rickettsia , fungi , parasites ,
mychobacterium(T.B.) , collagen tissue ,
e.g.: S.L.E. .
1/3rd of cases still no cause could be found .
Clinical features :- The onset is sudden or insidious (gradual) .
- Prodromal phase usually starts with flue-like
illness with cough , sore throat , fever .
- Headache , nausea , vomiting , blurring of
vision , papillodema (due to increase intra
cranial pressure) .
- Disturbance of consciousness , from
lethargy to deep coma ,covulsion.
- Focal neurological signs : according to area
involved .
- Skin rash & conjunctivitis in special types .
Diagnosis :- C.S.F. : show lymphocytic pleocytosis , slight increase in protein with normal sugar (only
decreased in mumps encephalitis)
occasionally may be normal . Very high protein
with very low sugar suggestive of tuberculus
infection (e.g.: tuberculoma ) .
- E.E.G. : show diffuse slow wave , focal
changes e.g.: temporal lobe abnormal finding
highly suggestive of herpes simplex virus .
Diagnosis (continue..) :- Neuro imaging : C.T. scan , M.R.I. may be
normal but may show focal lesion according
to the site involved or may show diffuse brain
swelling . Temporal lobe lesion suggestive of
herpes simplex virus(H.S.V.) .
- Serology : antibody-antigen reaction test
rising of titer against special virus like H.S.V.
4 fold or Igm type significant .
Diagnosis (continue..) :- Viral culture of C.S.F. , urine , stool ,
nasopharyngeal swab commonly reveal the
virus .
- P.C.R. : it is identify the virus through its DNA ,
it is highly specific and sensitive for C.S.F. ,
nowadays replaced the brain biopsy .
- Brain biopsy : the last and invasive procedure
rarely done for special types like T.B. & non
infectious causes
Differential diagnosis :- Reye syndrome(aform of hepatic encephalopathy).
- Hypoglycemia .
- Collagen vascular disease (C.V.A.) .
- Drugs & toxins .
- Hypertensive encephalopathy .
Treatment :Non specific : measures to be taken like
admission to I.C.U. then A,B,C,D .
Control convulsions by phenobarbiton .
Decrease intra cranial pressure by
dexametasone
and or mannitol .
Pay attention to fluid & electrolytes .
Treatment (continue..) :Specific : intra venous acyclovir for H.S.V ,
V.Z.V. they are only viruses susceptible to
drug therapy , otherwise there is no specific
treatment for other viral encephalitis .
Antibiotics for bacterial causes , e.g.:
mycoplasma (erythromycin) , T.B. (anti T.B.).
Others according to the cause , e.g. steroid for
S.L.E. .
Complication :Happen when there was no recovery within 2-3
weeks and they are common in spite of
proper treatment like ;
- Death : generally occur in about 5% of cases .
- Paresis , spasticity , ataxia .
- Cognitive impairment .
- Epilepsy due to recurrent seizures .
Prevention :Only two viral forms of encephalitis
could be prevented by vaccination
against them , they are influenza virus
and rabies virus vaccines done for
whom they are liable to get them .
Figure :
EBV encephalitis. a Axial FLAIR image demonstrates
abnormal T2-W signal in the bilateral frontal cortex and
subcortical white matter. This is a typical pattern for viral
encephalitis. The multiple vascular territories involved
make ischemia unlikely. Additionally, a child presenting
with multifocal strokes of this magnitude would have a
profound clinical presentation with fixed neurologic
deficits. b, c Axial (b) and coronal (c) FLAIR images
demonstrate increased signal in the bilateral basal
ganglia reflecting the unique tropism of EBV for this
Meningitis:
Definition
:
It’s inflammation of leptomeninges caused by
pathogenic microorganisms:
Bacteria:-strept.pneumoniae ,H.infleunzae
,meningococus
Viruses:- H.S.V,H.I.V,C.M.V,Mumps,enterovirus,
HLCM.
Fungi:-coccidiomycosis,Histoplasmosis,
Uncommon:-Lyme disease ,catscratch dis. ,T.B.
,Toxoplasmosis,
Entameba: Acanthomeba
: Acute bacterial(septic)meningitis:Bacteriology:
- Strept.pn.,nowadays commonest one
- H.infleunzae,about 5% of cases(b.of vaccination.)
- Meningococcus (Niserea meningitidis) .rare but most
serious and Weakest bacterium.
- Staph.aureas, common in post-surgical
cases&penetrated wounds .
- Pneunococcus:in fracture base of skull &C.S.F leak
Clinical features:
*It’s variable according to the age of the patient:
-Neonates and infants:
*Fever or hypothermia, drowsiness' or irritability
*Tense anterior fontanel, convulsion, unexplained
*Repeated vomitting,lethargy, relactant to feed.
-Older aged children:
*headache ,repeated vomiting , meningisim
,toxicity (neck stiffness ,kerning&brudzinesky
signs.)
C.F.continue:
Skin rash in form of purpura ,called purpura
Fulminance(in meningococcemia)
Adrenal hemorrhag:shock state called (water house fridrichsen syndrom)
-Signs of increase intracranial pressure
(hypertention,bradycardia ,irregular respiration).
-Focal nearological signs: ptosis , 6th N.pulsy, anisocoria
Usually there's no papilodema.
Diagnosis:
- C.B.P. :Shows neutrophil leukocytosis,with picture ofacute
bacterial inf .
- Positive acute phase reactants: high E.S.R.,+Ve C.R.P
- Blood culture &sensitivity may be +ve in about 90%
of cases.
- L.P for C.S.F. examination: us .show increase preasure,
cell count,(majority are neutrophils),protein,
&decrease sugar,coloure may be turbid.
- Signs of consumptive coageolopathy.or D.I.C.in
meningococcemia.
Contraindications of L.P.:
*Cardiopulmonary instability
*Infection in the site of L.P.
* Bleeding tendency.
*Papillodema.( absolute C.I.)
Normal C.S.F. parameter:
*Colure : clear
*pressure: <160mmH2O
*Cell count: 0-5Lymphocytes, No Neutrophils
*Protein: 15-35mg/dl
*Sugar: 50-80mg/dl(or 2/3rd of blood sugar)
*Culture: -ve.
But normal C.S.F. doesn't exclude meningitis.
D.Dx:*Encephalitis
*Intracranial hemorrhage.
*Encephalopathy.
*Posterior fossa tumore.
Treatment:
-Its one of ped. Top medical emergensy.
-Admission to hospital &in special isolated word.
-Control convulsion.
-Give I.V. fluid 2/3red of the daily requirement(to pre
-vent S.I.A.D.H).
-Anti-biotics :Empirical choice is combination of
vancomycine +one of third genration cephalosporins
(cefotaxime or ceftriaxon) double of the simple dose .-
-Steroid:Dexamethasone twice daily for two days.
Comlications:
*Early :Sub-dural effusion, Hydrocephalus,c.v.a.
Cerebral herniaition ,D.I.C, Adrenl hemorrhage
(water-house fridrichsen syndrome)
*Late :cerebral abscess ,cerebral pulsy,mental
retardation, epilepsy, deafness,blindness.
Prevention:
*Meningococcal vaccine for overcrowded areas
*Pneumococal vaccine: for Immune
compromised children.
*Chemoprophylaxis.:Rifampicin10mg/kg/dos
12hourly for 2 days for contacts with meningocoCcemia.
&10mg/kg/day single dose for 4days in H.infl.
-single inj. Of ceftriaxon ,oral ciprofloxacine are
Ulternatives.
THE END
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