So, let's talk about the clinical
features of brain abscess.
It can be an indolent sneaky infection
or fulminant symptoms and signs depending
upon the size and location of the abscess
and what it's pushing on or what it’s destroying.
Another determining factor is
the virulence of the infecting organism.
Most of the patients will present with headache.
It can be on one side of the brain
and it usually is on the same
side of where the brain abscess is.
And so, it can be a generalized
headache or hemi-cranial.
There are really no distinguishing factors,
and so that often results in a delay in diagnosis.
But if a patient has sort of an indolent
course and then becomes suddenly very ill,
that suggests that the brain
abscess has ruptured into the ventricles
and is causing now meningitis.
So, various pathogens
produce brain abscess.
We started earlier talking about Nocardia.
And I should point out at this point that
about 10% of the patients who develop
a Nocardio lung abscess
also have a brain abscess.
This is a very abscessogenic organism.
So, if you diagnose
lung abscess due to Nocardia,
the incidence of brain abscess
is so high that those patients
should have imaging of their brain,
symptomatic or not.
they are angioinvasive.
These are the bread molds.
And angioinvasive means that they invade blood vessels
and they then can occlude those
blood vessels and disseminate.
And most of the time,
it's in and around the paranasal sinuses.
And most of the time it’s
associated with diabetic ketoacidosis.
The absolute worst case of this I've ever seen
is a man that was treated
at an outside hospital for
some kind of infection on the skin, a cellulitis.
He was given antibacterial antibiotics.
And during the course of that hospitalization,
his glucose was out of control and he developed
diabetic ketoacidosis in the other hospital.
He then began to complain of nasal
congestion and trouble with his vision.
And they then transported him
to the Medical College of Georgia, where I work,
and at the time he arrived
he was absolutely sightless in both eyes.
He had no light perception in either eye.
His face was swollen
and you could almost
demarcate where the infection was.
He had essentially caused an infarction of his face.
This organism had invaded
all of the blood vessels in
and around his sinuses and face.
And it had spread already to his brain,
and so emergency surgery was done
because you have to cut this infection out.
Remember, if the blood vessels are occluded,
then how are antifungals even going to get there.
So, you’ve got to cut this entire infection out.
And the neurosurgeons and
ENT physicians, when they cut,
they kept finding fuzzy mold beneath
the skin and deep into the sinuses.
And the patient
literally had his face taken off by the surgeons.
And he was about to be fitted with a
mannequin like mast to place over his face,
but unfortunately he died of a bacterial meningitis
because of the proximity of all this surgery to his brain.
But I'll never forget that patient.
And the main reason I want
you never to forget it, anything –
in a diabetic with ketoacidosis,
anything suspicious about the sinuses,
those patients need an emergency workup
by ENT for invasive mucormycosis.
And then, we’ve already talked about the
association of near-drowning with Scedosporium.
Toxoplasma encephalitis in brain abscess
will present usually with confusion.
We’re usually talking about an HIV patient
and the patient may have
extrapyramidal findings because the
basal ganglia are frequently
involved in abscesses due to Toxo.
In a patient with aspergillosis,
this, like mucor and like the bread molds, is angioinvasive.
And the main patients at risk for this
infection are patients with neutropenia.
Indeed, the most common fungal infection in a
patient with leukemia and neutropenia is aspergillosis.
And a patient may actually present
as if they've had a stroke,
and so stroke in a leukemic victim should be considered
to possibly be Aspergillus until proven otherwise.