Patho Lab 2 Flashcards
Contracoup injury
1) Location of hemorrhage consistent with fall backwards (striking occiput) resulting in contracoup injury to inferior frontal and temporal lobes
2) Extensive contusions and subarachnoid hemorrhage
Vascular malformation
1) Causes hemorrhage (Intraventricular, intracerebral, subarachnoid)
2) 10-30 yrs old, M>F 2:1
3) Dilate, tortuous, worm-like vascular channels
4) May bleed a small amount to cause seizure
5) Arterial or venous (Large vascular malformation mimics brain tumor)
6) Histologically arteriovenous malformation (AVM)
7) Most common in cerebral hemispheres but may involve brainstem
Remote contusions
1) Orange-brown scalloped appearance (Hemosiderin from hemorrhage)
2) Old contusions
3) Crests of gyri are most susceptible to trauma
1) Secondary to downward compression -> stretching and ischemia of perforating arterioles
2) Compression may caused by hemorrhages, edema, mass lesions of any type
Duret hemorrhages (Pons)
1) Extensive white matter petechial hemorrhages
2) Neurologic signs and symptoms appear about a week after long bone fractures (e.g. vehicular accident)
Fat embolism syndrome
1) Yellow-tan or tan-green exudate -> obscured sulci
2) CSF from lumbar puncture shows low glucose, high protein, high PMNs (neutrophils, basophils, eosinophils) cell count
3) Gram stain to identify organisms
4) Edema and focal inflammation via Virchow-Robin space
5) Can lead to herniation and death
6) Resolution by adhesive arachnoiditis -> obliteration of subarachnoid space -> obstructive hydrocephalus
Acute bacterial meningitis
Aspergillus organisms (Fungus)
1) Like to invade vessels which cause hemorrhage and thrombosis
2) Seen in immunocompromised hosts (neutropenia)
3) Branching hyphae invading cerebral vessel
What causes green discoloration in aspergillosis?
Invasive fungal hyphae destroys BBB which causes leakage of bile pigments into the brain
1) Disseminated Aspergillus fungal infection
2) Patients that are markedly neutropenic
3) Areas of hemorrhage with brain swelling and midline shift
Aspergillosis with hemorrhage
Viral encephalitis
1) Involve cortex (encephalitis) sometimes with meningeal involvement (meningoencephalitis)
2) Rabies virus (specific), West Nile virus or echovirus (general)
3) Lymphocytic infiltrates in cortical parenchyma and cerebral vessels
4) CSF shows increased mononuclear cells, elevated protein, normal glucose
Herpes simplex virus encephalitis
1) Uncommon but distinctive viral infection
2) Sporadic and can occur in non-immunocompromised host
3) Hemorrhage in temporal lobe
4) Mononuclear cell infiltrates microscopically
1) Liquefactive center with yellow pus surrounded by thin wall
2) Caused by hematogenous spread of bacterial infection, direct penetrating trauma, extension from adjacent infection in sinuses
3) Trichrome stain shows light blue connective tissue in wall
Cerebral abscess
1) Marked dilation of cerebral ventricles
2) Lack of absorption of CSF or obstruction to flow of CSF
3) Long-term complication of infection (e.g. basilar meningitis may lead to scarring that obstructs foramen of Luschka or Magendie)
4) Inflammation of arachnoid granulations -> scarring and may diminish CSF absorption
Hydrocephalus
1) Holes in the cortex of the cerebrum
2) Spongiform encephalopathy
3) Rapidly progressive dementia
4) Poorly understood prion protein (infectious potential)
5) Cases appear sporadically (1 to 1 million)
Creutzfeldt-Jakob disease (CJD)
1) Appears grossly as irregular areas of granularity in white matter
2) Microscopically perivascular monocytes, astrocytosis (bizarre or enlarged astrocytes) & central lipid-laden macrophages
3) Periphery of lesions are large “ballooned” oligodendrocytes (infected with JC virus) that have enlarged dark pink “ground glass” nuclei (contains viral antigen)
Progressive multifocal leukoencephalopathy (PML)
