Infectious Disorders Flashcards
What type of pathogen is generally associated with an empyema?
Virus
What tissue does cerebritis involve?
The brain parenchyma
What is a formal definition of encephalitis?
Parenchymal infection generally referring to viral infections with necrosis, perivascular lymphocytic cuffing and microglial nodules
What type of reaction occurs in bacterial infections?
Vigorous polymorphonuclear (purulent) responses
What type of response occurs in a fungal/mycobacterial infection?
Indolent granulomatous rxns
What type of reaction does a viral infection produce?
Lymphocytic response
What type of reaction does a protazoal infection elicit?
Lymphoplasmacytic infiltrate
Describe the host response to prions
Vigorous gliosis
What type of response does a metazoan infection elicit?
Eosinophilic and lymphocytic inflammation
Where in the CNS do bacteria produce leptomeningitis?
Betwixt the pia and the arachnoid layers of the meninges
What are the classic signs of menigitis? What is Kernig sign and Brudzinski sign?
Headache, vomiting, fever, altered mental status, seizures, neck rigidity; knee pain with hip flexion (Kernigt), Knee/hip flexion when the neck is flexed (Brudzinski)
CSF lab findings in bacterial meningitis
Neutrophilia, decreased CSF glucose, elevated protein
What is the major cause of meningitis in newborns? Why?
E. Coli; For it to be neutralized, neonate requires IgM. IgM does not cross the placenta
What is the most common source of bacterial meningitis for young children?
Haemophilus Influenzae
A patient who was stationed in a barracks experiences lethal adrenal hemorrhage and expires. What syndrome did he have? What was the likely pathogen that caused his meningitis?
Waterhouse-Friderichsen Syndrome; Neisseria Meningititidis
A patient expires due to bacterial meningitis. Shown is a biopsy of the subarachnoid space. What type of cellular infiltrate is shown? What is the name for the pia that surrounds blood vessels and penetrates the brain?
Neutrophilic; Virchow-Robin spaces
What is the typical response to cerebritis? Which cell makes a rare appearance? What are the layers of a cerebral cyst?
Vigorous astrogliosis and fibroblasts; Fibroblasts;
- Granulation tissue
- Fibroblasts and collagen
- Astrogliosis, microglial activation and edema
What condition is hallmarked by plasma cells surrounding the arterioles of the cerebral cortex?
Meningovascular syphilis
A myelin section of the spinalcord is shown. The patient died of syphilis. What pathological process occurred in the spinal cord? What is this process called? What is a classic sign?
Posterior column degradation; Tabes Dorsalis; Unable to walk without visual cues because loss of proprioception
The lesion in the image shows caseous necrosis, macrophages and Langhans cells on histiologic analysis. What is the invading organism and what is the name of thee lesion?
Mycobacterium tuberculae; Tuberculoma
Tuberculosis of the spine is shown. What is the name of this deformity? What is this disease called?
“Gibbus” Deformity; Pott disease
Damn! This patient died of a brain infection. What infected him? How would you describe the lesions? Where is the infecting organism typically found? What stain would you use to identify the organism?
Cryptococcus (C. neoformans); Soap bubble lesions; In the Virchow-Robin spaces; India Ink
A patient was bitten by a bat and expired. What did he likely die of? What likely occurred in the CSF of this patient? What inclusion bodies are diagnostic and shown below?
Rabies; Increased lymphocytes, Increased Protein, Normal Glucose; Negri Bodies
A pteint with a history of cold sores dies. Histologic analysis is shown below. What are the diagnostic bodies shown below? What likely pathogen is this? What lobes were likely infected. If this was a newborn, how would the pathogen been acquired? What would the likely pathogen be?
Cowdry A bodies; HSV1; Temporal; Through the birth canal; HSV2
A child is born with hydrocephalus and expires. The histologic analysis of the brain is shown below. What are these inclusion bodies? What are they diagnostic of? How did the newborn acquire this pathogen? What other pathogens could cause similar pathologies?
Ependymal Inclusion Bodies; Cytomegalovirus; CMV crossed the placenta; TORCH pathogens
8 years ago a patient contracted measles. The patient expires and the brain histology is shown below. Intranuclear inclusions with halo rings are prominent in neurons and oligodendroglia in addition to marked gliosis and patchy loss of myelin. What is your Dx? Pathologic evolution?
Subacute Sclerosing Panencephalitis (SSPE); Measles virus with defective expression of viral M (Matrix) protein allowing the virus to proliferate without eliciting an immune response
This is a section of the medulla. Patchy demyelination is observed. What stain is used? What disease does this person have?
Luxol fast blue stain; Progressive Multifocal Leukoencephalopathy
This person has PML! What is the virus that causes this disease? When does it leave latency? What drug was taken off the market because it correlated with PML? How would you describe the biopsy below?
JC Virus; In immunocompromised patients; Natalizumab; Oligodendrocytes with enlarged nuclei containing hyperchromatic, “ground-glass” intranuclear inclusions lacking a halo
These large cells are shown in a perivascular location. What are they and what are they indicative of? What stain is used for the inset?
Multinuclearted giant cells of the monocyte/macrophage system containing HIV; anti-p24
A brain scan reveals symetric myelin pallor. What is your DDx? What is you Dx? Why?
HIVE or Progressive Multifocal Leukoencephalopathy; HIVE; Pallor is symmetrical
A patient had a brainscan that revealed a mass which was originally thought to be a tumor. A biopsy was taken. It was found that this infection is the most common mass lesion in patients with HIV. What protozoan infected this nice man?
Toxoplasma gondii
A nice man was swimming in a warm freshwater pond and then suddenly he had a brain infection. BOOM. What does he have? How can you tell that these are not macrophages?
Protazoan Naegleria spp.; They have less prominent nucleoli
A biopsy is shown characterized by individual and clustered vacuoles with no evidence of inflammation. What is the Dx?
CJD
