DEGENERATIVE DISEASES Flashcards
Most of the degenerative diseases, as are characterized by the selective involvement of anatomically and physiologically related systems of neurons. Thus, these degenerative diseases had in the past been
called_______
SYStem atrophies .
MOST IMPT mechanism that lead to neuronal degeneration
APOPTOSIS
the rate of cerebral atrophy, specifically
of the ____________, is accelerated in the early stages of Alzheimer
disease, and
hippocampus and medial parts of the temporal
lobes
The survival of patients with Alzheimer disease
is reduced to______ the expected rate, mainly because of
respiratory and cardiovascular causes and inanition, but
also for other reasons that are not entirely clear
half
The failial occurrence of Alzheimer disease has been
well established.
In less than ________ of such cases there
is a dominant inheritance pattern with a high degree of
penetrance and appearance of disease at a younger age
1 percent
Major sx of AD
The gradual development of forgetfulness is the major
symptom.
remote memories are preserved and recent ones lost
(the Ribot law of memory),
presence of cognitive difficulties in one or all spheres that are not severe enough to interfere with daily life
MCI
5 early symptoms of AD
1. amnesia 2 dysnomia 3. Visuospatial disorientation 4. Paranoia and personality changes 5. Executive dysfunction
The early stages of Alzheimer disease are
usually dominated by a disproportionate failure of
______
episodic (autobiographical) memory
AD definition according to NINCDS and ARDA
(1) dementia defined by clinical examination, the \_\_\_\_\_\_\_ (see Table 21-6), the \_\_\_\_\_\_ or similar mental status examination;
(2) patient older than age ___
(3) deficits in 2 or more
areas of cognition and progressive worsening of memory
and other cognitive functions, such as language, perception,
and motor skills (praxis);
(4) absence of disturbed
consciousness; and
(5) exclusion of other brain diseases
Mini-Mental Scale, Blessed
Dementia Scale,
40 years;
Using NINCDS and ARDA,
the correct diagnosis is achieved in more than ____
percent of patients,
85
________, the most prominent finding
visible on MRI (mainly coronal images), is diagnostic in the proper clinical circumstances.
atrophy of the hippocampus
Microscopically, there is widespread loss of nerve
cells. Early in the disease this is most pronounced in
____________
Layer II of the entorhinal cortex.
Pathology:
______ (more than proliferation) is in evidence as a
compensatory or reparative process, most prominent in
layers III and V.
Astrocytic hypertrophy
3 microscopic changes give this disease
its distinctive character
- Alzheimer neurofibrillary changes or
“tangles” - neuritic plaques
- Granulovacuolar degeneration
Alzheimer neurofibrillary changes or
“tangles” are composed of a
hyperphosphorylated form of the microtubular protein,_____and appear as pairs of helical filaments when studied
ultrastructurally.
tau
Amyloid is also scattered throughout the cerebral
cortex in a nascent “diffuse” form, without organization or core formation and then is appreciated mainly by
immunohistochemical methods, as well as deposition
in the walls of small blood vessels near the plaques, so called
__________
congophilic angiopathy.
This last change is least important
in diagnosis but there is uncertainty regarding its nature;
it had been thought to be simply a reactive process but
recent studies suggest it reflects a defect in phagocytosis of degraded proteins
Granulovacuolar degeneration
favored sites of neuronal loss
CAl and CA2 zones
(of Lorente de N6) and the entorhinal cortex, subiculum,
and amygdala.
_____ percent of their Alzheimer patients showed
the pathologic (and clinical) changes of Parkinson disease,
a much higher incidence than can be attributed
to chance
25
Electrophoretically, tau moves with the /32-globulins and
is thought to function as a _______, that is it binds iron
and delivers it to the cell
transferrin
The AB protein is a small portion of a larger entity,
the _____
amyloid precursor protein (APP),
During normal cellular
metabolism, APP is cleaved by either _______. The
products of this reaction are then cleaved by the __________ isoform of the enzyme
alpha and beta secretase
gamma secretase