Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
What Are the Symptoms of a Transient Ischemic Attack (TIA, Mini-Stroke)?
The symptoms of stroke and TIA are the same and depend upon the particular
region of the brain that is affected. But while a stroke is permanent, a TIA by
definition resolves its own.
Neurologic deficits appear suddenly and can affect the ability to move or
feel on one side of the body.
Speech and vision can be affected.
The affected
person may experience confusion, difficulty saying words, or the inability to
follow commands.
Because the brain is a large organ, the whole side of an individual's
body doesn't need to be affected. Symptoms may be limited to an arm or leg or part of the face. The
deficits are also grouped based on the anatomy of the brain. As an example, loss
of speech (aphasia) is associated with weakness or numbness on the right side of
the body, since speech is controlled by the left of the brain. These symptoms
are associated with problems in the anterior circulation from the carotid
arteries.
The brain controls how our body functions, how we think, how we see, how we
talk, and how we move. The signals to and from the brain are transmitted through
the spinal cord to the rest of the body.
The right side of the brain controls the left side of
the body, and the left side of the brain controls the right side of the body.
This includes movement and sensation.
Speech centers usually are located in the Broca's area on the left side of the brain.
Vision is controlled by the back of the brain in the occipital lobes.
The
carotid arteries
provide the majority of the blood supply to these parts of the brain (known as
the anterior
circulation).
Balance and coordination are controlled by the cerebellum, or the
base of the brain, and its blood supply comes from the vertebral arteries
located in the bony canals in the back of the vertebral column (referred to as
the posterior
circulation).
When an area of the brain loses its blood supply it stops
working and the part of the body it controls also stops working. This is what
happens with a stroke or CVA (cerebrovascular accident).
When the brain loses blood supply, it tries to restore blood flow. If blood
supply is restored, function may return to the affected brain cells, permitting
return of function to the affected body part. This is what happens with a TIA
(transient ischemic attack). Some may consider this a mini-stroke, however, in
reality, it is a stroke that has resolved or has improved functionality in the affected
body part.
By definition, a TIA resolves within 24 hours, but most TIA symptoms resolve
within a few minutes.
TIAs are often warning signs of a future stroke. The risk of a stroke
increases dramatically in the days after a transient ischemic attack,
and the TIA may offer an opportunity to find a cause or minimize the risk to prevent the permanent
neurologic damage that results because of a stroke.
Transient Ischemic Attack (TIA) Causes
Brain cells require oxygen and glucose to function. If the blood supply is lost, then
nutrient supply is lost, and the brain cells stop working. The blood supply to
brain cells can be lost in a few different ways.
Blood clots can form in one of the tiny arteries of the brain (thrombosis). This is
usually preceded by gradual narrowing of the blood vessel by fatty build-up
called plaque. Atherosclerosis
(atheroma=deposits of cholesterol and fatty tissue + sclerosis + narrowing) of
the brain arteries is the same as the narrowing that occurs in heart arteries preceding a
heart attack. A blood clot can form if the plaque ruptures, leading to further blockage of the artery.
Blood clots can float downstream from the heart and get caught in a tiny
blood vessel (embolus). Atrial fibrillation
(A fib) is the most common reason for an embolus. In atrial fibrillation, the
upper chambers of the heart jiggle and don't beat in a coordinated fashion.
This allows blood to become stagnant and form small clots. These clots can
embolize to any organ in the body, but the brain is a
common target.
Debris can occlude the blood vessels and stop blood flow. This debris often breaks off from
carotid arteries that are narrowed by the atherosclerotic disease process described
above.
Blood vessels can leak and cause bleeding within the brain tissue. An
intracerebral hemorrhage (intra=within + cerebral= of the brain +
hemorrhage=bleeding) is often caused by
high blood pressure which can cause small blood vessel
walls to become thin and weak.
The heart pumps blood into the arteries with enough force to push blood to
the far reaches of each organ from the top of the head to the bottom of the
feet. Blood pressure can be defined as the pressure of blood on the walls of the
arteries as it circulates through the body. Blood pressure is highest as its
leaves the heart through the aorta and gradually decreases as it enters smaller
and smaller blood vessels (arteries, arterioles, and capillaries). Blood returns
in the veins leading to the heart, aided by gravity and muscle contraction.
Hypertension is the medical term for high blood pressure. It is known as the
"silent killer" since it has no initial symptoms but can lead to long-term
disease and complications..
Many people have high blood pressure and don't know it.
