Meningitis

موضوع: Meningitis السبت مايو 15, 2010 6:37 am

Meningitis

Bonnie Mathews M.D.

Meningitis

n Infection causing inflammation of the membranes covering the brain and spinal cord

n Medical emergency with significant mortality

n Characteristic pathogens

n Bacterial meningitis or purulent meningitis

n Non-bacterial meningitis often referred to as aseptic meningitis

Bacterial Meningitis

n Most frequent in children age 2 months to 2 years of age

n Higher incidence during winter and spring

n Age specific pathogens

n Preterm to 1 month

n 1 to 3 monthse

n 3 months and older

Bacterial Pathogens-Preterm to 1 Month

n Bacterial pathogens likely acquired at or shortly after birth and seed meninges via hematogenous spread

n Group B Strep (49%)*

n E. Coli (18%)

n Listeria (7%)

n Enterococcus, Enterobacter, Klebsiella, Salmonella, Serratia (20%)

Bacterial Pathogens- 3 months and Up

n Bacteria spread via hematogenous dissemination from distant site or by aerosolization with nasopharyngeal colonization and subsequent invasion and bacteremia; rarely by local extension

n Streptococcus pneumoniae

n Hemophilus influenzae

n Neisseria meningitidis

n Group A strep

n Non-bacterial agents (aseptic)

Bacterial Pathogens- 1 month to 3 months

n Can be any of the agents typically seen in newborns or older infants and children

Pathogens- Special Situations

n There are certain situations which predispose children to particular pathogens

n VP shunts/penetrating head trauma- Staph epi

n Neural tube defects- Staph aureus, enteric organisms

n T-cell defects (HIV)- cryptococcus, listeria

n Sinus fracture- Strep pneumo

n Asplenia (HgB SS)- Neisseria, H. flu, S. pneumo

n Terminal compliment deficiency- Neisseria

Aseptic Meningitis

n All non-bacterial causes of meningitis

n Typically less ill appearing than bacterial meningitis

n Most common cause is viral

n HSV

n Consider especially in infants presenting with seizure

n Usually HSV type II

n Treat with acyclovir

n Enterovirus (coxsackie, echovirus)

n Typically occurs during late summer and fall

n Spread via respiratory secretions and fecal-oral

n Affects all ages

n Generally self-limited illness

Aseptic Meningitis

n Other Viral

n HIV

n Lymphocytic choriomeningitis virus

n Arbovirus

n Mumps

n CMV

n EBV

n VZV

n Adenovirus

n Measles

n Rubella

n Rotavirus

n Influenza and parainfluenza

Aseptic Meningitis

n Other infectious

n Borrelia burgdorferi

n Mycobacterium tuberculosis

n Treponema pallidum

n Mycoplasma pneumoniae

n Rickettsia, erlichia, brucella

n Chlamydia

Aseptic Meningitis

n Fungal

n Cryptococcus

n Coccidiodes

n Histoplasmosis

n Parasitic

n Angiostrongylus

n Toxoplamosis

Aseptic Meningitis

n Medication

n NSAID’s

n Bactrim

n Pyridium

n Malignancy

n Lymphoma and leukemia

n Metastatic carcinoma

n Autoimmune

n Sarcoid

n Behcet’s

n SLE

Clinical Presentation

n Clinical manifestations are due to local immune response to bacteria

n TNF-a and IL-B1 produced by activated macrophages and endothelial cells

n Neutrophils migrate from capillaries and release toxins

n Ensuing inflammatory response increases blood-brain permeability

n Cerebral edema

n Increased ICP

n Local thrombosis and infarction

Clinical Presentation Con’t…

n Bacterial meningitis usually presents in two patterns

n Acute (<1 day)- common with S. pneumoniae and N. meningitides

n Subacute (2-3 days)- preceding URI like symptoms, more common with H. flu and other pathogens

Clinical Manifestations

n Non-specific complaints, especially in young infant

n Irritability

n Restlessness

n Poor feeding

n Fever

n Headache

n Nausea and vomiting

n Anorexia

n Nuchal rigidity

n Lethargy

n Back pain

n Altered mental status (seizure, coma)

Physical Exam Findings

n May be subtle or nonexistent, especially in newborns

n Bulging fontanel

n Opisthotonos- stiff neck causing arched position

n Focal neurologic signs

n Petechia/purpura- DIC with N. menigitidis

n Positive Kernig’s and Brudniski’s

Purpura

Kernig’s Sign

n Patient placed supine with hips flexed 90 degrees. Examiner attempts to extend the leg at the knee

n Positive test elicited when there is resistance to knee extension, or pain in the lower back or thigh with knee extension

Brudzinski’s Sign

n Patient placed in supine position and neck is passively flexed towards the chest

n Positive test is elicited when flexion of neck causes flexion at knees and/or hips of the patient

Physical Exam Findings Con’t…

n Ptosis, anisocoria, papilledema, Cushing’s triad (bradycardia, hypertension, altered respirations) concerning for increased ICP with herniation-consider alternate diagnosis, i.e. space occupying lesion

Meningitis-Differential Diagnosis

n Brain abscess

n Encephalitis

n Epidural abscess

n Bacterial endocarditis with septic embolism

n Subarachnoid hemorrhage

n Tumor

Meningitis-Diagnosis

n Lumbar Puncture

n Locate L3-L4 disk space using superior iliac crests as landmarks

n Midline between spinous processes

n Aim for umbilicus

n Contraindicated in evidence of increased ICP, hemophilia or thrombocytopenia, infection in area of LP, or cardiorespiratory compromise

Meningitis-Diagnosis

n CBC

n Normal WBC does not rule out meningitis

n Low WBC concerning for sepsis

n Blood cultures- up to 15% of CSF positive meningitis in newborns will have negative cultures

n Electrolytes, renal function

n Serum glucose

n Useful to compare with CSF glucose

Lumbar Puncture-CSF Studies

n Tube 1: gram stain and culture, cell count

n Tube 2: glucose, protein

n Tube 3: cell count

n Tube 4: hold

n Bacterial antigen studies

n Viral PCR

n Fungal or mycobacterium cultures

CSF Diagnosis

CSF Diagnosis

n Cell Count

n Increasing RBC’s from Tube 1 to Tube 3 in setting of non-traumatic tap concerning for intracranial bleed or HSV

Meningitis- Empiric Antibiotic Choices

n Quick initiation of antibiotics is a must

n Supportive care only for aseptic meningitis

n HSV is the only exception

n Less than 1 month

n Ampicillin AND Cefotaxime

n Ampicillin-covers GBS and Listeria

n Cefotaxime-gram negatives including e.coli

n Amp/Gent also acceptable regimen

n Greater than 1 month

n Cefotaxime or Ceftriaxone AND Vancomycin

n 3rd generation cephalosporin will cover susceptible S. pneumo, Neisseria, and H. Flu

n Vancomycin covers resistant S. pneumo, MSSA, MRSA

n Need to use higher doses to allow penetration of the blood-brain barrier

Antibiotic Choices Con’t…

n Consider alternate antibiotics if child is at risk for particular pathogen

n Alter antibiotic choices once CSF gram stain results are available if appropriate

Meningitis-Treatment

n Supportive Care

n Fluids, treatment for shock and/or DIC, neuro checks

n Steroids

n Steroids thought to blunt effects of host inflammatory response

n Theoretical concern of steroids reducing permeability of blood brain barrier to antibiotics

n Most benefit seen with S. pneumo and H. flu

n Consider repeat LP 24-36 hours after initiating treatment to assure sterilization of CSF if resistant organism or poor response to treatment

Meningitis

n Even with appropriate antibiotics, mortality rate for bacterial meningitis is significant

n 8% H. flu, 15% Neisseria, 25% Pneumococcal

n Up to 35% of survivors have sequelae including deafness, seizures, LD, blindness, paresis, ataxia, hydrocephalus

n Poor prognosis associated with young age, long duration of illness prior to antibiotics, late-onset seizures, coma at presentation, shock, low CSF WBC with visible bacteria on gram stain, immunocompromised state

Meningitis- Prevention

n Chemoprophylaxis for close contacts of index case if Neisseria; treat contacts less than 4 years of age if H. flu

n Vaccinate all children, especially those at risk or those with asplenia

n H. flu

n S. pneumo- 7 valent up to 2 years, then 23 valent vaccine

n Neisseria- quadrivalent vaccine (A, C, Y, W-135) for high risk patients (asplenia, college age, military) over 2 years of age

n Does not cover group B, which causes close to ½ of cases in US

Question #1

n A 12 day old infant has not been feeding well for 24 hours. He was delivered vaginally at 37 weeks gestation to a 22 year old primagravida who had an uncomplicated pregnancy and labor. The infant has a week cry and a rectal temperature of 101.5. The CSF obtained by LP is cloudy.

Question #1…

n Of the following, the MOST likely cause of meningitis in this infant is

n E. Coli

n Klebsiella sp.

n Listeria monocytogenes

n Salmonella sp.

n Streptococcus pneumoniae

Question #2

n A 2 year old boy presents with fever, vomiting, and irritability. He cries during the physical examination and vigorously tries to push you away. You note obvious meningismus on examination of his neck but no focal deficits on the neurological examination. His vital signs are bp 95/65, rr 28, hr 120, temp 104.

Question #2…

n A TRUE statement regarding this child’s management is that

n Antibiotics should not be administered until after the CSF can be sampled

n Blood culture plays no role in the management of suspected meningitis

n Initial antibiotic choice should include ceftriaxone plus vancomycin

n IV fluids should be restricted to 2/3 maintenance

n The LP should not be performed prior to CT of the head

Question #3

n A 3 year old girl has had a temperature of 101.6 for 4 days. On physical examination, she has nuchal rigidity and appears irritable. However, she is alert and easily comforted by her parents. Following LP, CSF findings include a WBC of 450 with 60% PMN’s, glucose of 78 (serum glucose 90), protein of 50. Gram stain of the CSF shows no organisms.

Question #3…

n Of the following, the diagnosis MOST consistent with these CSF findings is

n Aseptic meningitis

n Bacterial meningitis

n Eosinophilic meningitis

n Partially treated bacterial meningitis

n TB meningitis

Question #4

n A high school student presents with a 24 hour history of fever, malaise, and bruising. Physical exam reveals an ill appearing teenager whose temperature is 103. He has nuchal rigidity, widespread petechiae, and areas of palpable purpura. Serum WBC is 18.5, Hgb 10, plt 25.

Question #4…

n Of the following, the organisms MOST likely responsible for these findings is

n Haemophilus influenzae B

n Neisseria meningitidis

n Pseudomonas aeruginosa

n Staphylococcus aureus

n Streptococcus pneumoniae

Question #5

n In regards to the patient in question #4, which of the following contacts should be chemoprophylaxed?

n A friend who spent the night at the boy’s home 10 days ago

n A student who sits next to him in class

n His girlfriend, who went out with him the evening before he became ill

n His grandmother, who lives next door to him

n The physician who performed his admission examination

موضوع: رد: Meningitis السبت يونيو 05, 2010 5:51 pm

شكرا لك دكتور وسام عاشت الأيادي وبوركت جهودك .جزاك الله خير الجزاء لجهودك المتواصلة

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خالص شكري وتقديري د-عبد الهادي الجريصي </p>
<p> Meningitis HaveANicedayRose

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موضوع: رد: Meningitis الأربعاء مارس 09, 2011 1:24 pm

نشكرك ياأخ وسام على هذه المعلومات الجيده أتمنى لك التوفيق
Surprised

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