Hemorrhages may occur at any site within the CNS. In some instances they may be a secondary phenomenon occurring, for example, within infarcts in arterial border zones or in infarcts caused
by only partial or transient vascular obstruction.
Primary hemorrhages within the_______________ are typically related to trauma and were discussed earlier with traumatic
Hemorrhages within the brain parenchyma and subarachnoid space, in contrast, are
more often a manifestation of underlying cerebrovascular disease, although trauma may also
cause hemorrhage in these sites.
Spontaneous (nontraumatic) intraparenchymal hemorrhages occur most commonly in middle to
late adult life, with a peak incidence at about age __________.
What is the Most are caused of intracerebral ( intraparenchymal hemorrhage? ________________
by rupture of a
small intraparenchymal vessel.
When the hemorrhages occur in the basal ganglia and
thalamus, they are designated _______________to distinguish them from those that
occur in the lobes of the cerebral hemispheres, which are called lobar hemorrhages.
In ganglionic hemorrhages the two
major underlying etiologies of this form of cerebrovascular disease are___________ and ___________.
In addition, other local and systemic factors may cause or
contribute to nontraumatic hemorrhage, including systemic coagulation disorders, neoplasms,
vasculitis, aneurysms, and vascular malformations.
cerebral amyloid angiopathy (CAA)
_____________is the most common underlying cause of primary brain parenchymal hemorrhage ,
accounting for more than 50% of clinically significant hemorrhages and for roughly 15% of
deaths among individuals with chronic hypertension.
Hypertension causes a number of
abnormalities in vessel walls, including ________________.
- accelerated atherosclerosis in larger arteries;
- hyaline arteriolosclerosis in smaller vessels;
- and, in severe cases, proliferative changes
- and frank necrosis of arterioles
_____________ affected by hyaline change are presumably weaker than
are normal vessels and are therefore more vulnerable to rupture.
In some instances chronic
hypertension is associated with the development of minute aneurysms, termed______________ which may be the site of rupture.
not to be confused with saccular aneurysms of larger intracranial vessels, occur in vessels that
are less than 300 μm in diameter, most commonly within the _____________
Hypertensive intraparenchymal hemorrhage may originate in the _________
(50% to 60% of cases), thalamus, pons, cerebellar hemispheres (rarely), and other regions of
the brain ( Fig. 28-18A ).
Acute hemorrhages, independent of etiology, are characterized by
extravasation of blood with compression of the adjacent parenchyma
Old hemorrhages show
an area of _____________.
cavitary destruction of brain with a rim of brownish discoloration
examination the early lesion consists of a central core of ___________________-Eventually the
edema resolves, pigment- and lipid-laden macrophages appear, and proliferation of reactive
astrocytes is seen at the periphery of the lesion.
The cellular events then follow the same time
course that is observed after cerebral infarction.
clotted blood surrounded by a rim of
brain tissue showing anoxic neuronal and glial changes as well as edema.
___________ is a condition in which amyloidogenic peptides, nearly always the same one found in
Alzheimer disease (Aβ40; see the discussion below), deposit in the walls of medium- and smallcaliber
meningeal and cortical vessels.
This deposition can result in weakening of the vessel
wall and risk of hemorrhage
As with Alzheimer disease, in which there is a relationship between
a polymorphism in the gene that encodes apolipoprotein E (ApoE) and risk of disease, there is
an effect of the ApoE genotype on the risk of recurrence of hemorrhage from sporadic CAA.
The presence of either an____________ allele increases the risk of repeat bleeding.
ε2 or ε4
mutations in the precursor protein for the________________) cause
familial Alzheimer disease, others result in autosomal dominant forms of CAA.
Aβ peptide (amyloid precursor protein, APP
The underlying vascular abnormality of CAA is typically restricted to the
_______________although involvement of the
molecular layer of the cerebellum can be observed as well.
- and cerebral cortical arterioles
- and capillaries,
What is the microscopic finding in CAA____________
Involved vessels appear “stiff” on
microscopic sections, remaining open with round lumens through tissue processing.
What is distinguishing feature of CAA to aretiolar sclerosis?
with arteriolar sclerosis, there is no fibrosis; rather, dense and uniform deposits of amyloid
_________________ is a rare hereditary form of stroke caused by mutations in the gene encoding the
Notch3 receptor. 
Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy
What is the characteristic of CADASIL?
The disease is characterized clinically by recurrent strokes (usually
infarcts, less often hemorrhages) and dementia.
What is the histopathologic study has shown abnormalities
of white matter and leptomeningeal arteries (also involving non-CNS vessels) consisting of
concentric thickening of the media and adventitia.
- Basophilic, PAS-positive deposits, which appear as osmiophilic compact granular material by electron microscopy, have been consistently detected in the walls of affected vessels,
- as has loss of smooth muscle cells ( Fig. 28-18C )
How is the diagnosis can be made in CADASIL?
through the identification of these deposits in other
tissues, such as skin or muscle biopsies, or through genetic approaches.
Many of the causative
mutations disrupt the normal folding of the extracellular domain of Notch3, and the
characteristic deposits appear to be comprised of Notch3 ectodomains. How these deposits
relate to the disease is not understood; a toxic gain-of-function mechanism affecting vascular
smooth muscle has been proposed
Intracerebral hemorrhage, independent of cause, can be clinically devastating if it affects large
portions of the brain and extends into the ventricular system, or it can affect small regions and
either be clinically silent or evolve like an infarct.
Over weeks or months there is a gradual
resolution of the hematoma, sometimes with considerable clinical improvement.
______________________ determines the clinical manifestations.
location of the hemorrhage
The most frequent cause of clinically significant subarachnoid hemorrhage is rupture of a
Subarachnoid hemorrhage may also result from extension of a
traumatic hematoma, rupture of a hypertensive intracerebral hemorrhage into the ventricular
system, vascular malformation, hematologic disturbances, and tumors.
saccular (berry) aneurysm
__________ is the most common type of intracranial aneurysm.
Other aneurysm types
include a_____________ These latter three, like saccular aneurysms, are most often found in the anterior
circulation, but differ in that they more often cause cerebral infarction rather than subarachnoid
- atherosclerotic (fusiform; mostly of the basilar artery),
- and dissecting.