Do you think Mr. C.’s memory problems are stroke
related?  If so, how would  the pathophysiology be
different for Alzheimer’s dementia?

Mr C’s memory loss could very likely be as a result of
his stroke.  As he has  residual left-sided weakness, it
is likely that he had a stroke involving the  right
hemisphere of his cerebrum.  Effects of right hemisphere
strokes may  include: •	Weakness or paralysis on the
left side of your body •	Vision problems. •	Problems
distinguishing distance, depth, between up and down, or 
between front and back. This can make it hard to pick up
objects, button a  shirt, or tie your shoes. •	Problems
understanding maps. •	Problems with short-term memory.
You may be able to remember  something that happened
several years ago, but not something you did a few 
minutes ago. •	Forgetting or ignoring objects or people
on your left side (this is called  neglect). You may
even ignore your own left arm or leg. •	Judgement
difficulties, such as acting impulsively or not
realizing your  own limitations (Heart and Stroke
Foundation, 2008).

Pathophysiology of Strokes:

The pathophysiology of a stroke involves the sudden loss
of brain function  caused by an interruption in blood
flow to the brain (termed ischemic stroke)  or the
rupture of blood vessels in the brain (termed
hemorrhagic stroke).   This causes the cells (neurons)
in the affected area to die.  The effects of the  stroke
are determined by the location of the injury in the
brain.

Ischemic strokes occur due to an interruption in blood
flow to the brain  caused by a blood clot. 
Atherosclerosis of the vessels is often involved, 
causing narrowing of the arteries that supply blood to
the brain.  Ischemic  strokes can either be thrombotic
or embolic: thrombotic meaning that the  blood clot
formed in an artery directly leading to the brain,
embolic meaning  that the clot developed elsewhere in
the body and then traveled to the brain  via the blood
stream.  This type of stroke accounts for approximately
80% of  all strokes.

Hemorrhagic strokes are caused by uncontrolled bleeding
in the brain, which  floods the brain and interrupts
normal blood flow, ultimately destroying the  brain
cells.  Two main types of hemorrhagic stroke exist:
subarachnoid  hemorrhage, in which the bleeding occurs
on the surface of the brain  (between the skull and the
brain); or intracerebral hemorrhage, where the  bleeding
occurs from an artery deep within the brain. 

The above information was adapted from the Heart and
Stroke Foundation  (2008).


Pathophysiology of Alzheimer’s Disease:

Alzheimer’s disease (AD) is a progressive, degenerative
disease of the brain,  and is the most common form of
dementia (dementia being defined as a  syndrome
consisting of loss of memory, judgment and reasoning,
along with  changes in mood, behavior, and communication
abilities (Alzheimer Society  of Canada, 2008).

Researchers do not yet know what causes AD or how to
stop it’s progression.   They have identified some
commonalities.

There were two hallmarks originally described by the
original identifying  physician (Dr. Alois Alzheimer
identified the disease in 1906).   •	The existence of
plaques, numerous tiny dense deposits scattered 
throughout the brain that become toxic to brain cells at
excessive levels, and •	‘Tangles’, which interfere with
vital processes and eventually choke off  living cells
(Alzheimer Society of Canada, 2008).

Tavee and Sweeney (2003) concur, describing that the
classic  neuropathological findings in AD include
amyloid plaques, neurofibrillary  tangles, and synaptic
and neuronal cell death

Other pathophysiologic changes that have been identified
include atrophy of  the brain in areas where brain cells
have degenerated and died.

Mr. C.’s memory loss could indeed also have an element
of AD to it.  Memory  loss, especially of recent events,
is a common symptom of AD, and may  indicate the
presence of AD.  Misplacing items is also common.  Mr.
C. is also  exhibiting mood changes, which could be
potentially related to AD.  Common  mood and behavior
changes may include confusion, becoming suspicious or 
withdrawn, or mood swings.

There are staging systems in place that many medical
professionals use to  determine the level of AD.  One
describes AD in terms of early stage, middle  stage, or
late stage; a second common staging system is the Global
 Deterioration Scale (Reisberg Scale), which divides the
disease into seven  stages.

Overall, it would be difficult given the information we
have to give a definitive  answer as to the exact reason
for Mr. C.’s memory problems.  Stroke seems  as though
the easy answer, given his history in the last few
weeks, but some  of the other behaviors (ie. suspicion)
lead one to think more along the lines of  AD.


References Alzheimer Society of Canada (2008). Retrieved
May 26, 2008, from 
http://www.alzheimer.ca/english/disease/whatisit-intro.htm
Heart and Stroke Foundation of BC and Yukon (2008). 
Retrieved May 26,  2008, from 
http://www.heartandstroke.bc.ca/site/c.kpIPKXOyFmG/b.3644593/
Tavee, J., & Sweeney, P. J. (2003). Alzheimer’s Disease.
Retrieved May 26,  2008, from 
http://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/ne
urology/alzheimers/alzheimers.htm#pathophysiology