This is Dr. Louis Caplan.
I'm dictating from Boston, Massachusetts.
I'm a clinical neurologist at
the Beth Israel Deaconess Medical Center in
Boston and professor of neurology at Harvard Medical School.
Today, I'm going to be talking about the clinical diagnosis of stroke and stroke subtypes.
The plan of the presentation is to first begin
by describing the nature of the subtypes and their importance,
how we make a diagnosis, and imaging evaluations.
One of the ways we do this is inductive reasoning.
That is, we try to acquire information first,
listening to the patient from the history about what kinds of
pathology it is and where it's located in the nervous system.
Then having thought about potential questions,
we do hypothesis directed questioning to answer those.
After we finish the history,
we generate probabilities of the pathology and stroke subtype.
Then, take time, think,
and plan the general neurological examinations to test
those hypotheses and then we revise the probabilities after the examination.
Finally, we plan the investigations to determine the diagnosis.
What is the importance of subtype diagnosis?
Well, the evaluation and also the treatment
differ dramatically between the different stroke subtypes.
The evaluation and management depend on the subtype and the nature,
location, and extent of the brain and vascular abnormalities.
Diagnosis is based either on
inductive reasoning which we just described or on pattern-matching.
If we have a friend named John and we know what John looks like,
when someone comes up,
we just match the pattern of John in our heads with what that person looks like.
The same with stroke subtypes if we know what the usual subtype is,
we match the patients finding with that
or we go through an inductive reasoning process.
Actually in many cases we do both.