Download - Cns infection in chidren
Acute CNS infection
• What is it?
• What causes it?
• What happens in the system?
• How to recognize it?
• How to prove it?
• How to treat it?
• How to prevent?
Significance
• Significant morbidity & mortality in children [1.2m cases worldwide]
• Diagnosis, challenging in young children
• High incidence of sequalae
• Fever with altered sensorium
• Virus > bacteria > fungi & parasite
• Meningitis
• Meningoencephalitis
• Brain abscess
• Common symptoms
photophobia, neckpain/rigidity, fits, stupor
• Diagnosis by CSF
Pyogenic meningitis
Etiology
• < 2months• Maternal flora, NICU/PNW flora;
• GBS, GDS, gram-ve, listeria, HIB,
• 2m-12m• Pneumococci, meningococci, HIB[now less]
• Pseudomonos, staph.aureus, CONS.
Reasons for infection
• Less immunity
• Contact with people with invasive disease
• Occult bacteremia [infants]
• Immunodeficiency
• Splenic dysfunction
• CSF leak , Meningomyelocele
• CSF shunt infection
Risk of infection
• Pneumococci OM, sinusitis, pneumonia, CSF rhinorrhea.
• Meningococci contact with adults, nasopharyngeal carriage
• HIBContact in daycare center
Pathogenesis
• Colonisation of nasopharynx
• Prior/concurrent viral URTI
• Bacteremia
• Hematogenous dissemination
• Contiguous spread from sinus, otitis, orbit
vertebral trauma, meningocele.
Why few only get meningitis?
• Defective opsonic phagocytosis– Developmental defects– Absent preformed anticapsular antibodies– Deficient complement/properdin system– Splenic dysfunction
Pathogenesis • Bacteria enter through choroid plexus of LV• Circulate to extra cerebral CSF & subarachnoid space• Rapidly multiply in CSF• Release of inflammatory mediators• Neutrophilic infiltrates• Increase vascular permeability• Altered BBB• Vascular thrombosis
Pathology
• Thick exudate covering all areas
• Ventriculitis, arteritis, thrombosis
• Vascular occlusion, sinus occlusion.
• Cortical necrosis, cerebral infarct
• Subarachnoid hemorrhage
• Hydrocephalus
• ICT, inflammation of spinal nerves
Clinical features • Nonspecific
– Fever,anorexia,myalgia,arthralgia,headache,– Purpura , petechiae, rash, photophobia.
• Meningeal signs– Neck rigidity, backache.– Kernig sign– Brudzinski sign– Crossed leg sign
ICT signs
Headache, vomiting, drowsy, Fits Ptosis, squint, AF bulge, widened sutures Hypertension, bradycardia Stupor, coma Abnormal posturing Papilloedema [only in chronic ICT]
• Focal neurological deficit
• Cranial neuropathy– 3rd nerve– 6th nerve– 7th nerve– 8th nerve
Diagnosis
• LP & CSF analysis– Gram stain– Culture– Cell count– Glucose, protein– [Contraindications for LP]
• Blood culture
CSF analysis• Cell count
– Normal• NB >30/mm3
• Child >5/mm3
– Meningitis >1000/mm3• Turbid 200-400/mm3
• Early; lymphocytic predominance
• Later; neutrophilic predominance
• low in severe sepsis
CSF analysis in prior antibiotic therapy
• Culture, gramstain altered
• Pleocytosis, protein, glucose unaltered
Traumatic LP
• Cell count, protein level altered
• Glucose, bacteriology unaltered.
Condition Pressure mm-h2o
Cell count/mm3 Glucose mg/dl
Protein mg/dl
microbiology
Normal 50-80 <5,lymphocyte >50, 75% of blood level
20-40mg
Bacterial meningitis
100-300 100-1000, >75% neutrophils
<40mg 100-500 Gram stain+ve
Partially treated meningitis
N / elevated
5-1000,Lymphocytes?
N /decreased 100-500 Gramstain ,c/s maybe -veAntigens +ve
Viral meningitis
Normal Less cells,lymphocytes
N, less in mumps
<200
TBM More <500,lymphocytes
<40 100-3000 Stain –veCulture ± ve
Fungal More 5-500 N More? Culture
Treatment • Rapidly progressive [ ~24h]
LP antibiotics
ICT , FND CTbrain & antibiotics
Manage shock, ARDS
• Subacute course [4-7d]
• Assess for ICT, FND
• Antibiotics CT LP
Supportive care• Monitoring
– Vitals– BUN,electrolytes,HCO3,IO, CBC,Platelets,Ca– Periodic neurologic assessment
• PR,sensorium,power,cranial N ex, head circ,
• Supportive care– IVF restrict for ICT,SIADH, more for shock – ICT ETI & ventilation,frusemide,mannitol– Seizures diazepam,phenytoin
Antibiotic therapy• Vancomycin & cefataxime/ceftrioxone
– Pneumococci,meningococci,HIB.
• Ampicillin / cotrimaxazole I.V– Listeria
• Ceftazidime & aminoglycoside– Immunocompromised
Duration of therapy
Pneumococci : 7-10 days Menigococci: 5-7 days HIB; 7-10 days E.coli,Pseudomonos ; 3 weeks Antibiotics started before LP [partially
treated meningitis] ; ceftrioxone 7-10 days.
Repeat LP
• After 48h
• For ; resistant pneumococci, gram-ve meningitis
Corticosteroids
• Rapid bacterial killing
• Cell lysis
• Release of inflammatory mediators
• Edema
• Neutrophilic infiltration
• 1-2h before antibiotics
• Dexamathasone q6h for 2 days.
• Less fever, less deafness.
Complications • ICT, Herniation
• Fits, Cranial N palsy
• Dural Vein sinus thrombosis
• Subdural effusion
• SIADH
• Pericarditis, Arthritis
• Anemia, DIC
Prognosis
• Mortality >10% [more in pneumococci]
• Prognosis poor in– Infants– Fits >4days– Coma, FND on presentation
• Neurological sequalae 20%– Behavior changes 50%– Deafness [pneumo,HIB], visual loss– MR,fits,
Prevention
• Meningococci– Rifampacin for close contacts [10mg/kg/day q12h for 2days]– Quadrivalent vaccine for high risk children
• HIB– Rifampacin for contacts for 4days– Conjugate vaccine
• Pneumococci – Heptavalent conjugate vaccine
Thank you
TBM
• Subacute / ?chronic meningitis
• From lymphohematogenous dissemination
• Caseous lesion in cortex / meninges
• Discharge of TB bacilli in CSF
• Thick exudate infiltrate blood vessels
• Inflammation,obstruction,infarct.
• Brainstem affected
• Cranial N dysfunction
• Hydrocephalus
• Infarcts
• Cerebral edema
• SIADH
• Dyselectrolytemia
Features • 6m-4yrs
• 3 stages
• Prodrome stage; 1-2 wks, nonspecific symptoms, stagnant development
• Abrupt stage;lethargy,fits,meningeal signs focal ND,cranial neuropathy,hydrocephalus.
Encephalitic picture
• Coma stage; posturing,hemi/paraplegia,poor vital signs
Diagnosis • Contact with adult TB
• Mx nonreactive 50%
• CSF – lymphocytes
• Glucose <40mg/dl
• Protein high: 400-5000mg/dl
• AFB +ve 30%
Thank you
Meningoencephalitis
• Acute inflammation of meninges & brain tissue
• CSF – pleocytosis
• Gram stain & culture negative
• Mostly self limiting
Etiology
• Enterovirus
• Arbovirus
• Herpes virus
Pathogenesis
• Direct invasion & destruction by virus• Host reaction to viral antigens• Meningeal congestion• Mononuclear infiltration• Neuronal disruption• Neuronophagia• Demyelination
Structures affected
• HSV; temporal lobe
• Arbovirus; entire brain
• Rabies; basal parts
Clinical features• Depends on parenchymal involvement• Preceding mild febrile illness & exantheme• Acute onset of high fever, headache,
irritability,lethargy,nausea,myalgia• Convulsions,stupor,coma• Fluctuating FND,emotional outburst• Ant.horn cell injuryflaccid paralysis [west
nile,entero virus]
DD
• Meningitis of various organisms
Diagnosis • CSF: lymphocytic predominance
– Protein: normal,high in HSV– Glucose: normal,low in mumps– Culture of organism [entero V]– Viral antigen by PCR– Culture from NPswab,feces,urine
• EEG: focal seizures [temporal];HSV• CT/MRI: swollen brain parenchyma
Treatment
• Acyclovir for HSV
• Non aspirin analgesic
• Nursing in a quiet room