Acute Meningitis Flashcards
Acute purple to infection within the subarachnoid space
Bacterial meningitis
Associated with CNS inflammatory reaction that may result in decreased consciousness, seizures raised intra cranial pressure and stroke
Organisms responsible for CNS community acquired
1, streptococccus pneumonia (50%)
- neisseria meningitidis (-25%)
- Group b streptococci (15%)
- Listeria monocytogenes (10%)
- Haemophilia influenzas (10%)
- common ever 8-12 years
Most common cause of meningitis in adults more than 20 years old
S. Pneumonia
Risk factors: acute or chronic sinusitis, otitis media, alcoholism,diabetes,splenectomy, hypogammaglobulinemia, complement deficiency and head trauma
N. Menigitidis
Creased due to immmunization with quadrivalent serogroup A,C,W135 an Y) meningococcal glycoconjugate
Serogropu B- responsible for 1/3 of cases of meningococcal disease.
Vaccinate 16-23 years old with MenB
Clue to diagnosis: purification,petecheal rashes
Previously responsible for meningitis in neonates:
Group B streptococcus or streptococcus agalactiae
Increasing in frequency with individuals aged >50 years
Increasingly important with neonatal meningitis 9<1month) pregnant women and individuals more than 60 years old
L. Monocytogenes
Acquired by ingesting food contaminated with listeria. Coleslaw, milk,soft cheeses and several ready to eat foods
Scomplication of the use of subcutaneous ommaya reservoirs and administration of intrathecal chemotherapy
S. Aureus
And coagulate negative staphylococci
Essential prerequisite for bacterial phagocytosis
Complement proteins and immunoglobulin
Critical event in the pathogenesis of bacterial menigitis
Inflammatory reaction induced by the invading bacteria.
Many of the neurologic manifestations and complications of bacterial meningitis result the immune response to the invading pathogen rather than from direct bacterial- induced tissue injury
Bacterial cell wall component of the gram negative
Lipopolysaccharide (LPS)
Teichoic acid and peptidoglycan of s. Pneumoniae
Chemokine s that act synergistically to increase the permeability of the blood-brain barrier, reduction of vasogenic edema and the leakage of serum proteins into the SAS
TNF alpha and IL 1B
Subarachnoid exudate of proteinacious material and leukocytes obstructs the flow of CSF trough the ventricular system and diminishes the resorptive capacity of the arachnoid granulations.
Leading to communicating hydrocephalus and concomitant interstitial edema
What combination changes in brain arenchyma leads to coma
- Interstitial
- Vasogenic
- cytotoxic edema leads to increase ICP
Triad of meningitis
Fever
He ache
And unchallenged rigidity
Decrease level of sensorium by >75% and can vary from lethargy to coma
Pathognomonic sign of meningieal irritation
Nuchal rigidity
Kernig: elicited with the patenting in the supine position thigh I sflexed over the abdomen with knee flexed, attempts to passively extend the knee elicit pain when meningeal irritation is present.
Brudzinkski: signs is elicited with the patient in supine position and is positive when passive flexion of the neck results in sponteneous flexion and hips and knee
Absent kernig and brudzinksi
- Very young
- Very old
Immunocompromised individual - Very depressed mental status
Seizure:
Focal:1. Arterial is he is
2.cortical venous thrombosis
3.focal edema
Generalised seizure activity and status epilepticus
- Hyponatremia
- cerebral anoxia
- less commonly
- toxic effects of antimicrobial meningitis
Raised ICP
Obtundation
Coma in disease
CSF opening pressure .180mmH20 and 20% have opening pressure >400 mmH20
- Decrease level of consciousness
2.papilledema
Dilated poorly reactive pupils - Sixth nerve palsies
4.decerebrate posturing - Cushing reflex: bradycardia,hypertension,irregular respiration’s
Classic CSF abnormalities
- PMN leukocytosis (>100 cells/uL in 90%)
- decreased glucose contraction (<2.2mmol/L /<40mg/dL)
- increased protein concentration (>0.45g/L (>45mg/dL in 90%)
- increased opening pressure (>180mmH20 in 90%)
Diffrenec between viral meningitis and bacterial meningitis
CSF profile of Viral meningitis: lymphocytic pleocytosis with normal glucose concentration concentration
CSF profile to bacterial meningitis:
PMN pleocytosis
Hypoglycorrhachia
HSV PCR 96% sensitivity: 72 hours of symptoms and within first week of antiviral therapy
Rickettsial disease: resemble bacterial meningitis
High fever prostration, myalgia, headache, nause and vomiting
Petcheal rash—> purification—.skin necrosis and gangrene
Dx: immunofluorescent staining of skin biopsy specimen
Ehrlichiosis
Transmitted by a tick bite Gram negative coccobacilli Two species 1. Anaplasma phagocytophylum -human granulomatous ehrlichiosis (Anaplasmosis)
- ehrlichichia chaffeensis
- human monocytic ehrlichiosis
Focal suppurative CS infections
- Subdural
- epidural empyema
- Brain abscess
Other
1. Subarachnoid haemorrhage (SAH)
Sub acute meningitis
Mycobacterium tuberculosis
Crypto coccus neoformans
Histoplasma capsulatum
Coccidiosis Emmitt is
Treatment for acute bacterial meningitis
60mins: patients arrival in the emergency room
S. Pneumonia
Tx: dexamethasone
Third or 4th generation cephalosporin
(Ceftriaxone,cefotaxime, cefepime) and vancomycin and acyclovir
Doxycycline: tick season
Cefepime more on enterobacteriasea and pseudomonas aurogenosa
Ampicillin for : L. Monocytogenes individuals <3months and age >55 years old
Metronidazole: cover gram-negative anaerobes in patients with otitis sinusitis or mastoiditis
Vancomycin and ceftazidime or meropenem forllowing surgical procure, staphylococci and gram negative-organism
Meningococcal meningitis
pen G. Remains the antibiotic of choice for meningococcal meningitis
Resistance to pen G.
- cefotaxime or ceftraixone
- 7 days course of intravenous antibiotic therapy for uncomplicated meningococcal meningitis
For close contact: chemoprpphylaxis
2 day regimen
1. Rifampin (600mg every 12 hours for 2 days in adults 10mg/kg q12hours for 2 days in children >1 year)
Rifampin not recommended for pregnant
Adult use: azithromycin 500mg or intra muscular ceftraixone 250mg
Pneumococcal meningitis: treatment
Cephalosporin (ceftriaxone, cefotaxime or cefepime) and vancomycin
Susceptible to penicillin: MIC <0.06
Resistant when MIC >12
Sensitive to s. Pneumonia. MIC <0.5
(Cefotaxime, ceftriaxone,cefepime)
MIC 1ug/L intermediate resistance treatment vancomycin
MIC >2ug/ml resistant
2 weeks course of IV antibiotic
Should have repeat LP after 24-36 hours
L. Monocytogenes
Ampicillin for at least 3 weeks
Gentamicin is added in critically ill patients 92mg/kg loading dose then 7.5 mg/kg per day given every 8 hours
Combination of trimethoprim (10-20/kg loading dose) and sulfamethozole (50-100mg/kg/per day) given 6 hours may provide an alternative in penicillin -allergic patients
Staphylococcal meningitis
S. Aureus and coagulase negative staphylococci is related with nafcillin
Vancomycin is a drug of choice for MRSA and patient allergic to penicillin
Gram negative bacillary meningitis
3rd generation cephalospohorin- cefotaxime,ceftraixone,ceftazidime
P. Aureginosa: ceftazidime or meropenem
3 week course of IV antibiotic
Adjunctive therapy
Inhibit the synthesis of ILB and TNF a at the level of mRNA, decreasing CSF outflow resistance and estabilizing blood brain barrier
Dexamthasone given 20 min before antibiotic therapy inhibits production of TNF alpha by macrophage ABG microglia
Decrease meningeal irritation an neurologic sequel are such as sensorineural hearing loss
The 1omg q 6 x 4 days
Vancomycin dose: 45-60mg/kg per day
Increase hypocampal injury and reduced learning capacity
Increase ICF treatment
Elevate patients head 30-45
Incubate and hyperventilate (paco2 25-30mmHg
Mannitol
Mortality rate
H. Influenza, N. Meningitidis, group B streptococci 3-7%
L. Monocytogenes 15%
S. Pneumoniae 20%
Risk of death from bacterial meningitis
- Decrease level of sensorium
- Onset of seizure within 24 hours
- signs of increased ICP
- young age (infancy) and age >50
- The presence of Conor I conditions including shock and need for mechanical ventilation
- Delay in initiation of treatment
Viral meningitis
Pleocytosis- normal or slightly elevated protein concentration (0.2-0.8gdL (20-80mg/dL)
Normal or slightly elevated opening pressure: 100-350mmH20)
PMN pleocytosis with low glocuse: CMV infection in immunocompromised host
As a rule: a lymphocytic pleocytosis wit low glocuse concentration should suggest fungal or tuberculous meningitis, listeria meningoencephalitis or non infectious disorder
PCR amplification of viral nuclei acid: single most important method for diagnosing CNS viral infections
Most common cause of viral meningitis
Enter obvious
-more than 85% of cases
EV17
- common in summer or fall
-lymphocytic pleocytosis (100-1000cells/uL), normal glucose and elevated protein concentration
- CSF reverse transcriptase PCR is diagnostic procedure of choice and is both sensitive and specific
- highest sensitivity within 48 hours
Arbovirus: common in summer
HSV meningitis: common viral in adults
HSV2: uncomplicated meningitis
HSV1: responsible to HSV encephalitis
Aseptic meningitis/ mollarets meningitis : due to HSV
EVb infections
Presence of atypical lymphocytes in the CSF or peripheral blood is suggestive of EBV
-almost never cultured
Dx: CSF serology: presence of viral IgM viral capsid antibodies (VCAs)
HIV meningitis
Cranial nerve palsies:
CN V, VII,VIII
Mumps
-late winter or early spring
More to male
Presence of parotitis, orchitis, oophoritis, pancreatitis or elevations of serum lipase and amylase
Mumps infection confers life long immunity
CS pleocytosis exceed 1000 cells/uL 25%
Lymphocytes 75%
CSF neutrophil is occurs more than 25%
Hypoglycorrhachia 10-30%: clue for diagnosis
LCMV infection: aseptic meningitis late fall or winter
House mice : mus muscular
Associated with rash, pulmonary infiltrates, alone is,parotitis,orchitis, myocopericarditis
Leukopenia,thrombocytopenia,abnormal liver function test
CSF pleocytosis (>1000 cells/ul) and hypoglycorrhachia (<30%)
Acute viral meningitis
Intravenous Acyclovir (15-30mg/kg per day in three divided doses
Followed by an oral drug such as acyclovir (800mg five times daily) famciclovir (500mg TID) or valacyclovir (1000 mg TID) for total course of 7-14 days.
Vaccination is effective method of preventing the develop emend of meningitis and other neurologic complications associated with poliovirus, mumps, measles, rubella and varicella infection.
A live attenuated vaccine (zostavax) is recommended for prevention of herpes zoster skin goes in adults more than >60
HZ/su for age >70 years
Sub acute meningitis
- H. Capsulatum
- C. Immitis
- T. Pallidum
- M. Tuberculosis
- C. Neoformans
CIP-TN
C. Neoformans: soil and birds
H. Capsulatum: ohio, Mississippi River, central US, central and sought America
C. Immitis: desert
Syphilis: sexually transmitted disease
CN VII and CN VIII
TB meningitis:
- Elevated opening pressure
- Lymphocytic pleocytosis (10-500)
- Elevated protein concentration in range of 1-5g/L
- decrease glucose concentration 1.1-2.2mmol/L 20-40 mg /dl
Culture 4-8 weeks
-gold standard
CSF fungal meningitis
Mononuclear or lymphocytic pleocytosis
Increased protein concentration
Decreased glucose concentration
C. Immitis: eosinophils
Treatment for sub acute meningitis
Empirical therapy
- basis on the high index of suspicion without adequate laboratory support.
Isoniazid (300mg/d) rifampin (10mg/kg per day pyrazinamide (30mg/kg per day in divided doses) ethambutol (15-25mg/kg) pyridoxine (50mg/day)
Dexamethasone for TB meningitis
12-16 mg/day for 3 weeks, then tapered over 3 weeks
Meningitis: c. Neoformans in non-HIV
Non transplant patients: amphotericin B (AmB) (0.7mg/kg/IV per day plus flucytosine (100mg/kg/day in four divided doses fo r 4 weeeks
Extended to 6 weeks for patients with neurologic complications
Consolidation phase 400mg/day for 8 weeks
Or again transplant Liposomal AmB (3-4mg/kg/per day) or AmB lipid complex (ABLC) 5mg/kg per day plus flucytosine (100mg/kg/ day in 4 divided doses) for at least 2 weeks
8-10 week course of fluconazole 9400-800mg/d (6-12mg/kg) PO if the CSF culture is sterile after 10 weeks
Then decreased to 200mg/d for 6 months to a year
HIV meningitis
AmB or lipid formulation plus flucytosine for 2 weeks by fluconazole for a minimum of 8 weeks
HIV infected: fluconazole 200mg/d
