meningitis and brain abscess
TRANSCRIPT
-
7/30/2019 Meningitis and Brain abscess
1/32
Meningitis and Brain abscess
-
7/30/2019 Meningitis and Brain abscess
2/32
-
7/30/2019 Meningitis and Brain abscess
3/32
-
7/30/2019 Meningitis and Brain abscess
4/32
CSF FLOW AND SPREAD OF
INFECTION
Produced by the Choroid plexus of the cerebralventricles
Exits through narrow foramina into thesubarachnoid space
Circulates around the base of the brain and over thecerebral hemispheres
Resorbed by arachnoid villi projecting into the
superior sagittal sinus.
-
7/30/2019 Meningitis and Brain abscess
5/32
CSF FLOW AND SPREAD OF
INFECTION
CSF flow provides a pathway for rapid spread ofinfectious and malignant processes over the brain,spinal cord, and cranial and spinal nerve roots.
Spread from the subarachnoid space into brainparenchyma may occur via the arachnoid cuffs thatsurround blood vessels that penetrate brain tissue(Virchow-Robin spaces).
.
-
7/30/2019 Meningitis and Brain abscess
6/32
-
7/30/2019 Meningitis and Brain abscess
7/32
Acute infections of the nervous
system
Acute bacterial meningitis
Viral meningitis
Encephalitis Focal infection: brain abscess, subdural
empyema, infectious thrombophlebitis
Fever & Headache
-
7/30/2019 Meningitis and Brain abscess
8/32
Meningitis
Acute infection of meningitis, important medical problem
Causes:
Infective: Bacterial
Viral: Enterovirus; mumps
Fungal: cryptococcus; candida
Protozoa: amoeba; toxoplasma; cysticercus
Non infective: Malignant disease: breast CA; leukemia; lymphoma; Bronchial CA
Inflammatory: Behcets disease; SLE; sarcoidosis
-
7/30/2019 Meningitis and Brain abscess
9/32
Acute bacterial meningitis
Acute purulent infection of the sub-arachnoid
space
Epidemiology:
Annual incidence: >2.5/100,000 population
Common organisms (community acquired):
Strep. pneumoniae: 50%
N. meningitidis: 25% adults (50% in >2 and 50yrs with underlying dis.) Listeria monocytogens: 10%
H influenza: < 10%
Staph aureus: neurosurgical procedure
-
7/30/2019 Meningitis and Brain abscess
10/32
Causative organisms
Age of onset Common Less common
Neonate Gramve bacil
Gr. B Strep.
Listeria
Pre school H. Influenza
N meningitidis
St. Pneumoniae
Older childrenand adult
N meningitidis
St. Pneumoniae
Listeria
H influenza
Staph aureus
-
7/30/2019 Meningitis and Brain abscess
11/32
Etiology
Strep Pneumoniae: most common in > 20yrs
Predisposing condn.
- pneumonia, sinusitis, otitis media,
- alcoholism, diabetes,
- splenectomy,
- hypogamma.,complement defn. Mortality: 20%
Neisseria meningitidis 25% Children and young adults: 60%
Petechial rash
Disease can be fulminant
Listeria monocytogens: < 1 month & >60 yrs; pregnancy, immunocompromised (all ages)
Ingestion contaminated food : milk products, meat products
-
7/30/2019 Meningitis and Brain abscess
12/32
Pathophysiology
Colonize nasopharynx
Intravascular space
Choroid plexus
CSF
Proliferation of bact.
Avoids phagocytosis
Absence effective host
defense mech
-
7/30/2019 Meningitis and Brain abscess
13/32
Pathophysiology
Most neuro. Manifest & complications: immune response to invadingpathogen and not direct bact. Induced injury
Injury can progress even after CSF sterilized
Lyse bacteriarelease of cell wall components (LPS, teicholic &peptidoglycan) in SA space cytokines (IL 1 & TNF)
WCC & CSF protein
Production of excitatory amino acids, reactive O2, nitrogen species
permeability of BB barrier: vasogenic oedema; protein in SA space
Sub arachnoid space exudates Obstruction of flow of CSF
Decrease resorptive capacity
Increase ICP
-
7/30/2019 Meningitis and Brain abscess
14/32
Clinical manifestations
Onset: rapid (few hours) or subacute (worsens overdays)
Classic clinical triad : Fever, headache, nuchual rigidity(Kernigs sign; Brudzinski sign)
level of consciousness 75% (lethargy to coma) Nausea and vomiting
Photophobia
Seizure (20-40%)
Focal: focal ischemia or infarction; cv thrombosis; focal edema Generalized: hyponatremia; cerebral anoxia; toxic effect of Penn.
Rash: meningococcemia
-
7/30/2019 Meningitis and Brain abscess
15/32
-
7/30/2019 Meningitis and Brain abscess
16/32
-
7/30/2019 Meningitis and Brain abscess
17/32
-
7/30/2019 Meningitis and Brain abscess
18/32
Clinical manifestations
ICP 90%
Signs: level of consiousness
PapilloedemaDilated and partly reacting pupils
VI th nerve palsy
Decerebrate posture
Cushingss reflex: pulse rate, HTN, irreg. resp
-
7/30/2019 Meningitis and Brain abscess
19/32
Diagnosis
Suspected blood culture empiricalAntibiotics
Diagnosis by CSF examination
LP safely done in: Immunocompetent person
normal level of consiousnessNo PapilloedemaNo focal neurological signs
-
7/30/2019 Meningitis and Brain abscess
20/32
-
7/30/2019 Meningitis and Brain abscess
21/32
Cond. Cell Count Glucos Protein
mg/dL
Gram
Normal Lymph 0-4 >60% bl 0 to 45 _
Viral Lymph 10-2000 N N _
Bact. Polym. 1000-5000
N/ +
TB Lymp/mixed
50-5000 Often-
Fungal Lymph 50-500 +/-
Malig Lymph 0-100 N/ -
-
7/30/2019 Meningitis and Brain abscess
22/32
Diagnosis
CSF in pyogenic meningitis PMN leucocytes (>100/microL) 90%
glucose (< 40 mg/dL) 60%
protein ( > 45 mg/dL) 90%
pressure (> 180 mm H2O) 90%
Gram stain: 60% Culture: >80%
Causes of low CSF glucose Fungal
TB
CA
Imaging : CT or MRI, latter preferred
Biopsy of petechial lesions: Meningococcemia
-
7/30/2019 Meningitis and Brain abscess
23/32
Differential Diagnosis
Viral meningo encephalitis: HS virus CSF: normal glucose and lymphocytosis
MRI : high intensity signal lesions
EEG
Rickettsial disease fever, headache, myalgia and nausea and vomiting
Rash in 96 hrs
Focal suppurative CNS infection subdural and epidural empyema
Brain abscess
Non infectious diseases SAH
Inflammatory
-
7/30/2019 Meningitis and Brain abscess
24/32
Treatment
Start Antimicrobial: Goal, < 60 mins arrival to ER
Empirical before CSF results Patients with typical meningococcal rash
- Benzylpenicillin 4 megaunits 6 hrly
Adults : 18 -50 without typical meningococcal rash- 3rd gen. Cephalosporin ( ceftriaxone 2 g 12 hrly)
Penn resistant pneumocci suspected
- 3rd gen. Cephalosporin + Vancomycin 1 g 12 hrly
Listeria suspected ( < 3/12 and > 55 yrs)
- 3rd gen. Cephalosporin + Ampicillin 2 g, 4 hrly H/O anaphylaxix to B lactam
- Chloramphenicol 25mg/kg, 6 hr + Vancomycin 1 g 12 hrly
-
7/30/2019 Meningitis and Brain abscess
25/32
Adjunctive Treatment
Dexamethasone: 20 minutes before antibiotic therapy.(Before the macrophages and
microglia are activated by endotoxin)
No benefit if started > 6 hrs after Ab therapy
Dose: 10 mg, 6 hrly for 4 days
Benefits synthesis of IL1 and TNF
CSF outflow resistance
stabilizing the BB barrier
Reduce the number of unfavorable outcomes- unfavourable outcome 15% vs 25%
- death: 7% vs 15%
-
7/30/2019 Meningitis and Brain abscess
26/32
Adjunctive Treatment
Treatment of raised ICP
Elevation of patients head 30-45 degrees
Intubation and hyperventilation (PaCo2 25-30
mmhg)
Mannitol
-
7/30/2019 Meningitis and Brain abscess
27/32
Prognosis
.
Poor prognostic markers
decrease level of cons.
seizure in 24 hrs Sign of increase ICP
Young age & >50 yrs
Co morbid condn.
Delay in starting treatment
decrease CSF glucose (3 g/l)
-
7/30/2019 Meningitis and Brain abscess
28/32
Prevention of meningococcal
infection
Indication
HH and other close contacts of pt. with
meningococcal infections
Drug:
Rifampicin : 10 mg/kg, 12 hrly for 2 days
Ciprofloxacin: 500 mg single dose
Vaccines: available for prevention of
Group A and C.
-
7/30/2019 Meningitis and Brain abscess
29/32
Course and prognosis
Mortality: 3 to 20%
Poor prognostic factors: level of consciousness
Increase ICP Onset of seizure within 24 hrs
Extremes of age
Delay in treatment
low CSF glucose (< 40 mg/dl)
Sequele intellectual fxn
memory impairment
seizure Extremes of age
Difficulty in gait
-
7/30/2019 Meningitis and Brain abscess
30/32
Viral meningitis
Most common cause Usually benign and self limiting illness requiring notherapy
Common organisms: echo & mumps
C/F:
Children or young adults affected Headache, irritability, fever and meningnism
Focal neurological signs: rare
Investigation; CSF: (verify that pt. has not received
antibiotics lymphocytes
Glucose normal
Protein: normal or raised
Treatment: No specific treatment. Recovery in few days
-
7/30/2019 Meningitis and Brain abscess
31/32
Brain abscess
Pathogenesis & Etiology
Penetrating injury, direct spread from paranasal
sinus or middle ear
Hematogenous spread: septicaemia
Initial infection suppuration loculation of pus
surrounding wall of gliosis
Etiology
StreptococciAnaerobes
Staphylococci
-
7/30/2019 Meningitis and Brain abscess
32/32
Brain abscess
Investigations LP hazardous
CT: single or multiple low density areas with ring enhancement andsurrounding oedema
DD: cerebral toxoplasmosis and tuberculoma
Management Medical treatment: small abscess (