Lecture 2 Neuropathology of CNS Infections Flashcards
How do infectious organisms access the CNS?
- hematogenous spread
- local extension (middle ear)
- retrograde transport
- direct implantation (surgery)
Pachymeningitis
spread of infection into layers of the dura mater
-“pachy” = thick
Meningitis/Leptomeningitis
inflammation of the pia and arachnoid
What does lepto mean
“thin”…so leptomeningitis = thin
Encephalitis
inflammation of the brain parenchyma with MONONUCLEAR cells
-usually caused by VIRAL agent
Mononuclear infiltration of brain parenchyma
Encephalitis
Cerebritis
inflammation of the brain parenchyma with neutrophils
-usually caused by a bacterial agent
Polynuclear infiltration of brain parenchyma
Cerebritis
Myelitis
inflammation of the spinal cord
Poliomyelitis
inflammation of spinal gray matter (like the ventral root/horn)
Ganglionitis
inflammation of the dorsal root ganglia
Radiculitis
inflammation of the intradural spinal nerve roots
What is granulamatous inflammation associated with in brain?
- mycobacteria
- spirochetes
- fungi
- parasites
What are microglial nodules associated with?
Viral encephalitis
What are the most common bacterial infections?
- Acute bacterial meningitis ACUTE
- Bacterial abscess ACUTE
- Mycobateria (tuberculosis) CHRONIC
- Multisystem bacterial infections CHRONIC
What layer of the brain most commonly gets fucked in bacterial CNS infections?
Subarachnoid space (leptomeningitis/meningitis)
What are the most common bacteria that cause acute bacterial meningitis in NEONATES (0-6months)?
- Group B Streptococcus
- E. coli
- Listeria monocytogenes
What are the most common bacteria that cause acute bacterial meningitis from 6mos – 60 years?
- Streptococcus pneumonia
- Neisseria meningitides
- Haemophilis influenza
(accounts for 80% of all cases)
What are the most common bacteria that cause bacterial meningitis in >60 y.o. and immunosuppressed patients?
- Strep pneumonia
2. Listeria monocytogenes
How does acute bacterial meningitis present in gross examination? histological examination?
- Pus
2. Polys