Nervous System Flashcards
Acute neuronal injury becomes evident on routine H&E staining within __ hr/s of an irreversible hypoxic/ischemic insult
12h
Manifestations of acute neuronal injury
- Shrinkage of cell body
- Disappearance of the nucleolus
- Intense eosinophilia of the cytoplasm
(“red nucleus”) - Loss of NIssl substance
Neuronal processes become thickened and tortuous in some neurodegenerative diseases
Dystrophic neurites
Principal cells responsible for repair and scar formation in the brain
Astrocytes (hyperplasia and hypertrophy)
Degenerative change in astrocytes; round, faintly basophilic PAS(+) concentrically lamellate aggregates of polyglucosans
Corpora amylacea
This virus preferentially infects:
A. Oligodendroglioma
B. Ependymal cell
A. JC virus (progressive multifocal leukoencephalopathy)
B. CMV (congenital CMV)
Macrophages develop elongated nuclei in neurosyphilis or other infections
Rod cells
The brain accounts for only 1-2 of the body weight but receives __% of the resting cardiac output; and accounts for __% of the total body oxygen consumption.
15% of CO
20% of total O2 consumed
Widespread ischemic/hypoxic injury occurs when there is a generalized reduction of cerebral perfusion. This occurs with systolic pressure < ____.
Global cerebral ischemia.
<50 mmHg
Areas of the brain MOST susceptible to ischemia of short duration
- Pyramidal cells of the Sommer sector (CA1) of the hippocampus
- Purkinje cells of the cerebellum
- Pyramidal neurons in the neuronal cortex
In the cerebral cortex the neuronal loss and gliosis produce an uneven destruction of the neocortex, with preservation of some layers and involvement of tohers.
Pseudolaminar necrosis
In the cerebral hermispheres, the border zone between the _____ distributions is at greatest risk for watershed infacts.
MCA and ACA
The territory of distribution of the ____ - the direct extension of the ICA - is most frequently affected by embolic infarction.
MCA
The most common sites of primary thrombosis in the cerebral vasculature.
- Carotid bifurcation
- Origin of the MCA
- Either end of the basilar a.
Tissue liquefaction after brain infarct occurs ___ after injury
10 days to 3 weeks
The gliotic layer of tissue that delimits the cavity from the meninges and subarachnoid space, developing several months after an infarct, is derived from:
Molecular layer fo the cortex
Hypertensive intraparenchymal hemorrhages typically occur in the:
- Basal ganglia
- Thalamus
- Pons
- Cerebellum
Cerebral amyloid angiopathy is a disease in which amyloidogenic peptides deposit in these vessels leading to ___ hemorrhages.
Leptomeningel and cortical
(sparing of the vasculature of the white matter and deep gray structures).
Lobar hemorrhages
Most frequent cause of clinically significant subarachnoid hemorrhage
Saccular aneurysm (Robbins) Trauma! (Greenberg)
Overall, cerebral aneurysms have a roughly ___% per year rate of bleeding
1.3%
Most common locations of saccular aneurysms
AComm (40%)
MCA (34%)
ICA-MCA (20%)
PCA (4%)
The sac of saccular cerebral aneurysms is made up of
Thickened hyalinized intima.
Absent muscular wall and intimal elastic lamina
Most common vascular malformation in the brain
AVM
Differentiate cavernous from capillary hemangiomas in the brain.
Both are dilated, thin-walled vascular channels. Cavernous hemangiomas are devoid of intervenous nervous tissue (with low flow; no arteriovenous shunting); while capillary telangiectasias are separated by relatively normal brain parenchyma.
Most common location of capillary hemangioma
Pons
Most common location of cavernous hemangioma
Cereberellum
Pons
Subcortical regions
Differentiate cavernous from capillary hemangiomas in the brain.
Both are dilated, thin-walled vascular channels. Cavernous hemangiomas are devoid of intervenous nervous tissue (with low flow; no arteriovenous shunting); while capillary telangiectasias are separated by relatively normal brain parenchyma.
Most common location of capillary hemangioma
Pons
Most common location of cavernous hemangioma
Cereberellum
Pons
Subcortical regions
Lacunar infarcts are arbitrarily defined as small infarcts <___mm wide.
15
Inflammatory disorder that involves multiple small to medium-sized parenchymal and subarachnoid vessels; characterized by chronic inflammation, and multinucleated giant cells. Affected individuals develop diffuse encephalopathy. Treatment?
Primary angiitis of the CNS.
Treat with steroids.
Most common location of contusions
Frontal lobes along the orbital gyri
Temporal lobes
T/F. In brain trauma, superficial layers of the brain are preserved and gliotic.
False. Superficial layers are most severely affected. Statement is true for infarcts.
Area of the spinal cord most often affected by syringomyelia
Cervical spinal cord