00:01
So let’s talk about that one parasitic
known as cerebral toxoplasmosis.
00:06
First and foremost,
who's your patient?
A greater importance once again
in AIDS epidemic unfortunately
and the organism, gondii,
Toxoplasma gondii,
is one of the most common causes of
neurologic symptoms in AIDS patients.
00:25
What is CT or MRI
going to show you?
You should know a list of differentials
that will give you ring-enhanced lesions.
00:37
We’ll talk about brain
abscess coming up.
00:39
Toxoplasma will give you
ring-enhanced lesion.
00:43
What does that mean?
I’ll show you a picture
later, whereupon CT,
you find this ring around
the brain parenchyma.
00:51
You could have toxoplasma.
00:53
It could be brain abscess.
00:55
Later on, we’ll talk about
gliobastoma multiforme,
but that is a heterogeneous
type of ring-enhanced lesion.
01:02
At this point, we’ll go with the basics.
01:05
Ring-enhanced lesion is a very important
point or description or finding
for further differentials
and pathology.
01:12
A similar findings with CNS lymphoma,
tuberculosis, or fungal infection.
01:17
Toxo.
01:19
There is a trial of toxo
therapy if necessary.
01:21
Toxo is the most common cause of cerebral
mass lesion in patients with AIDS.
01:27
So as soon as you hear about AIDS and you
see a ring-enhanced lesion upon imaging,
you should be
thinking about toxo.
01:35
If you take a look at this particular
imaging, what do you find?
A ring-enhanced lesion.
01:42
You find a ring-enhanced lesion such
as this apart from toxoplasmosis.
01:47
You should be thinking
about abscess formation.
01:49
You see that, right there?
Perfectly, perfectly ring-like structure.
01:55
If this patient has a
CD4 count less than 50
and AIDS, in fact, has unfortunately
settled in, most likely toxoplasmosis.
02:06
In laboratory workup,
what are you going to do?
CSF findings, if negative, a trial of
therapy may still be attempted though.
02:14
Okay. So once again, can send
serum and CSF serology,
but if negative, still if you
know your patient has AIDS,
you still do empiric
type of therapy.
02:26
Treatment, avoid steroids.
02:28
It actually hampers
differential diagnosis.
02:31
Your pyrimethamine,
sulfadiazine or folinic acid.
02:35
Life-long maintenance is required here if
patient most likely immunocompromised.
02:43
Another type of parasitic
infection here,
apart from toxoplasmosis,
would be neurocysticercosis.
02:50
This is a tapeworm and
this is your soul pig.
02:54
"I’m sorry what?"
Take a look Taenia solium
and think of this pig,
pork is what you should
be thinking, right?
And I’ll go ahead and call this
soul pig if that helps you.
03:05
There are different
types of Taenia.
03:07
At least know solium, please.
03:09
The most common parasitic
infection of the CNS worldwide.
03:13
Look at this,
not necessarily, immunocompromised really
for the first time in a long time.
03:20
We talked about Cryptococcus, meningoencephalitis
and that was immunocompromised.
03:24
We did toxoplasmosis.
03:26
That patient was
immunocompromised.
03:28
Here, we have neurocysticercosis.
03:31
Most common parasitic
infection of CNS worldwide.
03:34
Notice, we do not have an
immunocompromised patient.
03:38
Are we clear?
Endemic in Mexico and
Central America.
03:43
Brain involvement
in 50-70% of your cases.
03:47
Let’s talk about the clinical
presentation of neurocysticercosis.
03:51
I’m going to bring in a couple
of integration points here.
03:55
Seizures.
03:58
Headaches due to increased
intracranial pressure.
04:00
So worldwide, most common
parasitic CNS infection, right?
And your patient is
exposed to what organism?
Taenia solium.
04:12
And what was I
being silly about?
Pork.
04:17
What’s interesting is that
you might then form --
Take a look at the middle
portion of this name.
04:23
Neuro-, cyst-,
-cercosis.
04:28
What if this cyst
ruptures in the brain?
Now, what do we call
this technically?
Good.
04:35
Whenever you have a
cyst that ruptures,
you call this separately
“chemical meningitis”.
04:42
Is that clear?
The last time we saw a
cyst that were rupturing
is when we talked about dermoid
tumor or for that matter
any type of cyst
that may rupture.
04:52
Here, exactly the same thing.
04:55
With neurocysticercosis,
here is an imaging
and an arrow particularly pointing
to that cyst-like structure.
05:03
"Dr. Raj, how can I tell that this is a
cyst and not a ring-like structure?"
This is a ring enhancing
cystic lesion.
05:10
As you can see
the outer ring lit up
surrounding a slightly more
radiolucent central structure.
05:17
This indicates an active cyst as
would be seen in neurocysticercosis.
05:23
With neuroimaging, I want you to be
really careful with this statement.
05:27
Now, the ring enhancing
cystic lesion,
we have an active cyst.
05:32
Remember in the middle,
you're going to be completely,
well for the most part,
it would be filled with fluid,
it'd be a cyst.
05:41
The parenchymal calcification,
even older cyst,
and the vasogenic edema.
05:45
Now, this is quite interesting here
and you want to pay attention
in the detail here.
05:50
Why do you want to know
so much detail about this?
Because it is the most common
parasitic sinus infection worldwide.
05:56
Okay. And you don't have to be
immunocompromised.
06:01
So if it's an active lesion,
and there's a cyst,
granted, maybe
it's ring enhancing, okay.
06:06
But more commonly,
the presentation,
the picture that I gave you earlier
that imaging study,
if you took a look at the middle,
it wasn't transparent, right?
It was not loosened.
And so therefore, it was calcified.
06:21
Most commonly,
that is a presentation
that you might be given.
06:24
But just to be technical,
yes, it could be bring enhance
if with an active cyst,
but usually by the time
the patient is going to present,
you're going to find that the cyst
has now become calcified,
which means that you have
a very, very opaque structure.
06:39
Is that clear?
And finally, the type of edema
will be vasogenic.
06:43
What does that mean to you?
It means that this is
an inflammatory process.
06:47
And if it's an
inflammatory process vasodilation
and you edema have
released a fluid or escape of fluid
from your blood vessels
resulting in what's known as
vasogenic edema.
07:01
In the cerebral spinal fluid,
usually normal
and may show
mononuclear pleocytosis,
maybe mild increase in protein,
but there is enough information here
without CSF analysis
to know that you're dealing
with neurocysticercosis.
07:18
Treatment: Seizures with
antiepileptics that is important.
07:23
What does this seizure mean to you?
We know for a fact that the cause
of seizures in neurocysticercosis
is related to neuroinflammation
and the release of P substance
and not the space occupying
nature of the lesion.
07:37
You should remember that these
lesions are usually quite small.
07:42
When you think of cyst is?
A space occupying lesion
may then result in seizures.
07:47
Yeah, albendazole,
it kill the parasite.
07:50
And steroids to maybe
control the inflammation.
07:54
Continuing our discussion
of infectious type of CNS.
07:59
We have more common in
immunocompromised patients
but this time we're parasitic.
08:04
Under these, we have toxoplasma.
We'll talk about cysticercosis.
08:09
There's malaria, amebiasis,
and also trypanosomiasis.
08:14
You've heard of trypanosoma before,
in reference to
Trypanosoma cruzi and Chaga.
08:20
We'll talk about toxo,
talk about cysticercosis.
08:23
Parasitic meningoencephalitis.
08:26
More commonly, once again
found in immunocompromised.
08:29
We have now,
all I've talked about so far
just fungal and cryptococcal
that's where
your focus should be on.
08:35
Now, we moved on to parasitic.