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Pediatrics                                                                    TUCOM                                                                          Dr.Bahaa

 

1

 

 

MENINGITIS 

 

 

Q1- What are the 

most

 common signs and symptoms of 

meningitis in infants <2 months old? 

 

 

In general, the findings among neonates and young infants with meningitis are 
minimal and often subtle.  

1-Temperature instability (fever or hypothermia) occurs in approximately 
60% of infected infants; 
2-Increasing irritability is present in about 60%, 
3-Poor feeding or vomiting in roughly 50%,  
4-Seizures in about 40%.  
5-Lethargy, respiratory distress, and diarrhea are frequent nonspecific 
manifestations of meningitis in this patient group.

  

On physical examination,  

1- 25% of newborns and young infants have bulging fontanels,  
2- Only 13% have nuchal rigidity.

  

The diagnosis of meningitis cannot be excluded based on the absence of these 
physical findings in infants. 

 

 
 

 

Q2- What is the percentage of neonates with bacterial sepsis and 
positive blood cultures have meningitis. 

 

 

Up to 25% of infants <28 days old with bacterial sepsis and positive blood 
cultures will have culture-confirmed meningitis.  

 

 
Q3-What is the most common cause of aseptic meningitis? 

 

Aseptic meningitis is defined as clinical and laboratory evidence of 
inflammation of the meninges (e.g., CSF pleocytosis and increased protein) 
without evidence of bacterial infection on Gram stain or culture.

  

More than 80% of cases are caused by enteroviruses (i.e., coxsackievirus, 
enterovirus, echovirus, and, rarely, poliovirus). West Nile virus is an increasingly 
common cause of aseptic meningitis, especially in the late summer and early fall.  
 

 

Q4- What is the diagnostic test of choice for enteroviral 
meningitis? 
 

 

PCR is highly sensitive and specific, and it is more rapid than viral cultures, 
which typically take 2-5 days to become positive. 


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Pediatrics                                                                    TUCOM                                                                          Dr.Bahaa

 

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Q5-Is intracranial pressure elevated in patients with meningitis? 

 

 

In acute bacterial meningitis, pressure is elevated in up to 95% of cases. 
Elevation is also common among patients with tuberculous or fungal meningitis. 
The frequency of elevation in patients with viral meningitis is less well studied. 

 

 

 
Q6. Should CT scans be performed before a lumbar puncture 
(LP) during the evaluation of possible meningitis?

 

 

CT scans are not routinely indicated before an LP, unless one of the following is 
present:  

1-Signs of herniation (rapid alteration of consciousness, abnormalities of 
pupillary size and reaction, absence of oculocephalic response, fixed oculomotor 
deviation of eyes) 2-2-Papilledema  
3-Abnormalities in posture or respiration  
4-Generalized seizures (especially tonic), which are often associated with 
impending cerebral herniation  
5-Overwhelming shock or sepsis  
6-Concern about a condition mimicking bacterial meningitis (e.g., intracranial 
mass, lead intoxication, tuberculous meningitis, Reye's syndrome)  

 

 
Q6. What is the range of values found in CSF of infants and 
children who do not have meningitis?

 

 

 

Preterm newborn infants: WBC count, 0-29/mm

3

; protein, 65-150 

mg/dL; blood glucose, 55-105 mg/dl  

 

Term newborn infants: WBC count, 0-32/mm

3

; protein, 20-170 mg/dL; 

glucose, 44-248  

 

Infants and children: WBC count, 0-6/mm

3

; protein, 15-45 mg/dL; 

glucose, 60-90 

 

 

Q7. If bloody CSF is collected during a lumbar puncture, how is 
CNS hemorrhage distinguished from a traumatic artifact?

 

 

Most often, the blood is a result of the traumatic rupture of small venous plexuses 
that surround the subarachnoid space, but pathologic bloody fluid can be seen in 
multiple settings (e.g., 

subarachnoid hemorrhage, herpes simplex encephalitis

). 

Distinguishing features that suggest pathologic bleeding include the following:  
1-Bleeding that does not lessen during the collection of multiple tubes.  
2-Xanthochromia of the CNS supernatant  
3-Crenated RBCs noted microscopically  


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Pediatrics                                                                    TUCOM                                                                          Dr.Bahaa

 

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Q8. How do the CSF findings vary in bacterial, viral, fungal, and 
tuberculous meningitis in children beyond the neonatal period? 

 

Although a large overlap is possible (e.g., bacterial meningitis can be associated 
with a 

low WBC count early in the illness, or viral meningitis can often be 

associated with a predominance of neutrophils 

early or even persistently in the 

illness). 
 

 

Q9. How is a traumatic lumbar puncture interpreted? 

 

To interpret the number of WBCs in the CSF after a traumatic lumbar puncture, 
the following correction factor can be applied. It is important to emphasize that 
the corrected WBC count is an estimate and should be considered in the context 
of other clinical information.  

 

 

Table 11-5. TYPICAL FINDINGS IN BACTERIAL, VIRAL, FUNGAL, AND 
TUBERCULOUS MENINGITIS 

Cerebrospinal fluid findings Bacterial 

                        

Viral 

      

Fungal/tuberculous 

White blood cells per mm

3

 

>500 

<500 

<500 

Polymorphonuclear 
neutrophils 

>80% 

<50% 

<50% 

Glucose (mg/dL) 

<40 

>40 

<40 

Cerebrospinal fluid to blood 
ratio 

<30% 

>50% 

<30% 

Protein (mg/dL) 

>100 

<100 

>100 

 

 

Q10. When is the best time to obtain a serum glucose level in an 
infant with suspected meningitis? 

 

Because the stress of a lumbar puncture can elevate serum glucose, the serum 
sample is ideally obtained just before the lumbar puncture. When the blood 
glucose level is elevated acutely, it can take at least 

30 minutes

 before there is 

equilibration with the CSF. 
 

 

 
 
 

 


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Pediatrics                                                                    TUCOM                                                                          Dr.Bahaa

 

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Q11. How often does bacterial meningitis appear in younger 
patients with normal findings on the initial CSF examination? 

In up to 3% of cases in children between the ages of 

3 weeks and 18 months

 with 

positive bacterial cultures of the CSF, the initial CSF evaluation (i.e.,

 cell count, 

protein and glucose concentrations, and Gram stain

) can be normal. Of note is 

that, in almost all of these cases, physical examination reveals evidence of 
meningitis or suggests serious illness and the need for empiric antibiotics. 
  

 

Q12. Does antibiotic therapy before lumbar puncture affect CSF 
indices? 

 

In most cases, shortly after the initiation of antibiotics, the CSF Gram stain still 
demonstrates bacteria with typical staining properties, and chemistry values and 
cell counts are abnormal. Even when children have received appropriate 
antibiotic therapy for 

44-68 hours

, chemical and cytologic analysis of the CSF 

generally still reflects a bacterial process. In earlier studies of patients with 
Haemophilus influenzae meningitis who received oral antibiotic therapy before 
lumbar puncture, CSF cultures often grew the organism. 

By contrast, there is a 

tendency for oral therapy to sterilize the CSF of children with meningococcal 
disease or with meningitis because of sensitive Streptococcus pneumoniae. 

  

 

Q13. What are the most common organisms responsible for 
bacterial meningitis in the United States? 

 

0-1month old : 
Group B streptococci  
Escherichia coli  
Listeria monocytogenes  
Streptococcus pneumoniae  
Miscellaneous Enterobacteriaceae  
Haemophilus influenzae (especially other than type b)  
Coagulase-negative staphylococci (in hospitalized preterm infants)  
1-23Months old  
Streptococcus pneumoniae  
Neisseria meningitidis  
Group B streptococci  
2-18  Years old  
Neisseria meningitidis  
Streptococcus pneumoniae  

 

 


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Pediatrics                                                                    TUCOM                                                                          Dr.Bahaa

 

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KEY POINTS: MINIMAL DURATION OF THERAPY 
FOR BACTERIAL MENINGITIS 

1. 

Five days of therapy for 

meningococcal meningitis  

2. 

Between 7 and 10 days for 

Haemophilus influenzae 

meningitis  

3.  Ten days for 

pneumococcal meningitis

  

4. 

Between 14 and 21 days for 

group B streptococcal or 

Listeria monocytogenes meningitis  

5.  Twenty-one days or more for 

gram-negative enteric 

bacilli

 (after the cerebrospinal fluid has become sterile)  

6.  Among patients with complications 

(e.g., brain abscess, 

subdural empyema, delayed CSF sterilization, 
persistence of meningeal signs, prolonged fever)

, the 

duration of therapy should be individualized and may 
need to be extended  

Q15. Why are Haemophilus influenzae type B strains more 
virulent than nontypeable Haemophilus
 strains? 
 

 

H. influenzae type b expresses the type b polysaccharide capsule, which is a 
polymer of ribose and ribitol-5 phosphate.  
In the absence of type-specific antibody, the type b capsule promotes 
intravascular survival by preventing phagocytosis and complement-mediated 
bactericidal activity. It is likely that other factors also contribute to the unique 
virulence of H. influenzae type b. 
 

 

Q16. What are the drugs of choice for the empirical treatment of 
bacterial meningitis in children >1 month old? 

 

In cases of suspected bacterial meningitis, both 

vancomycin and a third-

generation cephalosporin are recommended for empirical therapy

 because 

resistance to penicillin and cephalosporins is present in 

10-30% of Streptococcus 

pneumoniae isolates

. The exception is when the Gram stain suggests another 

etiology (e.g., gram-negative diplococci). Treatment failures have been reported 
when the dosage of vancomycin is 

<60 mg/kg/day

. Vancomycin should not be 

used alone to treat S. pneumoniae meningitis because data from animal models 
indicate that bactericidal levels may be difficult to maintain. The combination of 

vancomycin plus cefotaxime or ceftriaxone 

has been shown to produce a 

synergistic effect in vitro, in animal models, and in the CSF of children with 
meningitis.  


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Pediatrics                                                                    TUCOM                                                                          Dr.Bahaa

 

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Q17. How quickly is the CSF sterilized in children with 
meningitis? 
 

 

In successful therapy, the CSF is usually sterile within 36-48 hours of the 
initiation of antibiotics. In patients with meningococcal meningitis, CSF is 
typically completely sterile in no longer than 2 hours after starting treatment. 
With other organisms, the time until sterilization is generally at least 4 hours.  
 

Q18. How long after treatment has been initiated, must 
individuals with meningitis remain in respiratory isolation? 

 

 

Respiratory isolation is recommended for patients with suspected Haemophilus 
influenzae
 type b or meningococcal meningitis, but it can be discontinued after 

24 hours of therapy

.  

 

 

Q19. What is the accepted duration of treatment for bacterial 
meningitis? 

 

 

The duration of antibiotic treatment is based on the causative agent and clinical 
course. In general, a minimum of 5 days of therapy is required for meningococcal 
meningitis, 7-10 days for Haemophilus influenzae meningitis, and 10 days for 
pneumococcal meningitis. Disease as a result of group B streptococci or Listeria 
monocytogenes
 should be treated for 14-21 days, and meningitis caused by gram-
negative enteric bacilli should be treated for a minimum of 21 days after the CSF 
has become sterile. Among patients with complications such as brain abscess, 
subdural empyema, delayed CSF sterilization, persistence of meningeal signs, or 
prolonged fever, the duration of therapy may need to be extended and should be 
individualized. 
  

 

 
 
 
 
 
 
 

 
 
 

 


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Pediatrics                                                                    TUCOM                                                                          Dr.Bahaa

 

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Q20. What is the role of corticosteroids in the treatment of 
bacterial meningitis? 

 
The inflammatory response plays a critical role in producing the CNS pathology 
and resultant sequelae of bacterial meningitis. Several studies have demonstrated 
that treatment with dexamethasone 

reduces the incidence of hearing loss and 

other neurologic sequelae in infants and children with Haemophilus 
influenzae meningitis

. For cases of meningitis caused by pathogens other than 

H. influenzae, the current recommendations by the American Academy of 
Pediatrics are to consider the use of dexamethasone. The role of steroids in 
meningitis caused by other bacterial pathogens (particularly Streptococcus 
pneumoniae)
 remains controversial. 
  

 

 

Tuberculous meningitis 

 

Generally occurs within 

6-8

 weeks of primary pulmonary infection or during 

miliary tuberculosis (TB).  
Commonest in age range 

6 months to 3 years

Leads to basal arteritis, which may cause hydrocephalus and cranial 
neuropathies.  
Symptoms: 
otherwise are often non-specific, lethargy, fever, headache. 
CSF - high white cell count, 

predominantly lymphocytes

, raised protein often > 2 

g/dl, low glucose, tuberculous cultures may be positive. 
Treatment: 
1-Antituberculous chemotherapy 
2-Optimal treatment not determined 
3-Usually triple therapy (rifampicin, isoniazid, pyrazinamide) for at least 6 
months but 
4-Many authorities suggest a fourth drug for the first 2 months 
5-The place of corticosteriods in treatment is unclear but these are often used in 
the first few months to reduce inflammation 
6-

Mortality and morbidity remain high despite treatment.

 

            
 

                                      


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Pediatrics                                                                    TUCOM                                                                          Dr.Bahaa

 

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Encephalitis 

 

Numerous viruses may lead to inflammation of the brain: herpes viruses, 
adenoviruses, arboviruses and enteroviruses for example. 
 
 The underlying causative agent in undiagnosed encephalitis may remain 
obscure. It is therefore usual practice to treat with 

cefotaxime/ ceftriaxone, 

acyclovir and erythromycin/azithromycin until results are available.

 

 
Clinical features: 
Confusion, coma, seizures, motor abnormalities 
Infection usually starts to resolve 7-14 days after the onset. However, recovery 
may be delayed for 

several months.

 

 
Herpes simplex encephalitis: is 
Commonoften-focal

 brain inflammation, 

located in temporal lobes

High mortality, high morbidity 

(50%)

Specific 

treatment is acyclovir. 
 
Investigations for encephalitis 
1-CSF examination/cultures 
2-Electroencephalogram 
3-Brain imaging 
4-Occasionally, brain biopsy 
Treatment 
1-Supportive (fluid management/ventilation if necessary) 
2-Acyclovir 
 
 
 
 
 
 

 
 
 
 
 
 


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Pediatrics                                                                    TUCOM                                                                          Dr.Bahaa

 

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Immune-mediated and other infectious disorders 

 

1-Sydenham's chorea 
Main neurological feature of rheumatic fever 
Chorea results from immune reaction triggered by Croup A streptococcal 
infection 
May be associated with emotional liability 
Probably overlaps with PANDAS (psychiatric and neurological diseases 
associated with streptococcal infection) 
In about 

75%

 of cases the chorea resolves 

within 6 months.

 

 
2-Subacute sclerosing panencephalitis: 
A slow viral infection, caused by an atypical response to measles infection. 
Exposure to measles virus is usually in the 

first 2 years

. Risk is higher after 

contracting' natural measles, compared with that after measles immunization. 
Median interval between measles and subacute sclerosing panencephalitis is 

years. 

Clinical features:

 

1-Subtle deficits initially 
2-Increasing memory difficulties 
3-Worsening disabilities - seizures, motor difficulties, learning disability 
 
3-Mycoplasma encephalitis 
Mycoplasma pneumoniae is the 

commonest cause of community-acquired 

pneumonia in adults and commonly leads to infection in the pediatric age 
range

. It may cause encephalitis, predominantly through immune-mediated 

mechanisms, which may respond to steroid administration. The evidence base is 
small. 
 
4-Acquired immune deficiency syndrome 
Caused by human immunodeficiency virus, an RNA retrovirus which eventually 
leads to the death of its host cell 

CD4-positive T lymphocyte. 

Neurological features include: 
1-Neurological features of opportunistic infection such as meningitis or 
encephalitis  
2-Dementia 
 

GOOD LUCK 




رفعت المحاضرة من قبل: Abduljabbar Al-Kazzaz
المشاهدات: لقد قام 40 عضواً و 249 زائراً بقراءة هذه المحاضرة








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