Here, we have brain abscess.
With the brain abscess, acute focal
suppurative infection of brain parenchyma.
What does suppurative mean to you?
Under brain abscess, there
might be direct seeding.
Local extension, meaning to say
that you have a type of infection
taking place down in the
mastoiditis or sinusitis.
Or it could be hematogenous.
Acute bacterial endocarditis.
Or cyanotic congenital heart defects.
So anyone of these
type of presentations
could then result in
eventual brain abscess.
Clinical features: Headache,
nausea with vomiting,
papilledema, focal neurologic,
Elevated CSF, WBC count,
and here we go,
lesion on CT or MRI.
So now let’s step back for one second
and at least, at least, review
the three different ring enhancing
lesion that we’ve seen.
AIDS patient, immunocompromised.
Most common CNS infection in an
AIDS patient, toxoplasmosis.
What if serology comes back to be negative?
You still move forward with treatment
because your patient has AIDS.
How long do you give therapy?
Then we looked another
ring enhancing lesion
during active, active, infection
It could be ring enhancing.
But I told you most common presentation
would be a calcified cyst in the brain
and then we have brain abscess.
And here, we have ring enhancing lesion.
Pathogenesis, well, we’ll just walk through
how maybe a patient has endocarditis.
Maybe there is a direct seeding, so
on and so forth, hematogenous spread.
Edema, ring enhancing lesion,
and an abscess core.
So in other words, this time,
we don’t have calcifications.
So therefore, we have a
ring with an abscess core.
What does an abscess
core mean to you?
And what does that abscess core mean to
you apart from neutrophils coming in?
What kind of necrosis is this?
What if there is no identification
of structure of that organ?
It will be liquefactive necrosis.
Because neutrophils are destroying
everything in its path.
Our topic now brings
us to encephalitis.
Let me make sure that we’ve organized
our thoughts before we move on.
Up until this point, we have pretty
much looked at meningitides,
CNS infections, and now we are dealing
with infection of the brain parenchyma.
Confusion, delirium, focal
neurologic seizures and coma.
Let me ask you something.
If your patient has meningitis,
how likely is it that your patient may have
seizures if it was strictly meningitis?
Maybe, not necessarily.
But now, what if you have a
spreading into the brain,
There’s every possibility that
seizures might be taking place.
Now, the infections, they come
into the following categories:
Arboviruses, including your St. Louis,
eastern/western equine, West Nile virus.
And where we will be spending
time with will be HSV-1 herpes.
If your patient is in a
state of immunocompromised,
maybe cytomegalo, EBV, or even
What’s my topic?
And you’ll notice
for the most part,
these are viruses that are
commonly found as etiologies.