00:02
Here, we have transmissible
spongiform encephalopathy
In other words, our prion diseases.
00:07
And please make sure that you’re quite
familiar with spongiform encephalopathy.
00:12
Unbelievably, it behaves
like an infection.
00:15
However, the prions are very,
very difficult to kill.
00:20
They are extremely refractory.
00:22
You do everything and
these things just live.
00:24
It’s amazing, like survival.
00:27
Here, the diseases
include mad cow disease.
00:30
You've heard of
Creutzfield-Jakob disease,
Gerstmann–Sträussler–Scheinker
syndrome,
fatal familial insomnia,
and kuru.
00:41
These are all different
types of prion diseases
based on different
sources of the prion,
which is then causing these
particular pathologies.
00:50
A different twist in pathology and
microbiology all together prion is.
00:58
So what’s prion disease?
All associated with abnormal forms of
specific protein, a prion protein,
which behaves like
it’s become infected,
and then worse, it becomes
transmissible, fascinating.
01:13
Prion protein, usually, a
normal protein neuron.
01:16
Stop there.
01:17
So you have a prion
protein, which is normal.
01:20
All of a sudden, it got
exposed to something,
Creutzfield-Jakob,
Kuru, what have you,
in which now the prion
becomes “infectious.”
Prion protein undergoes conformational
change from alpha to beta-pleated sheet.
01:37
Make sure that you
memorize this.
01:39
This is when it becomes
“transmissible.”
Now, the prion protein
acquires relative resistance.
01:48
When I say relative resistance,
this thing, man, it
doesn’t want to die.
01:52
It’s like a cockroach.
01:54
Ever tried to kill a cockroach?
You try to step
on this cockroach
and you want to come back and you
want to put it into a trash can.
02:00
And you come back, the
cockroach is gone.
02:03
It’s unbelievable.
02:04
Prion behaves the same way.
02:06
Very, very resistant to
digestion with proteases.
02:11
Infectious nature comes from
ability to corrupt the integrity
of the normal
cellular components.
02:17
Very tricky, this disease,
isn’t it, in general?
Prion.
02:20
Transmissible spongiform.
02:23
Clinical features of
Creutzfield-Jakob disease.
02:28
Dementia, usually.
02:30
It’s like Alzheimer’s.
02:31
Let’s do multiinfarct dementia.
02:34
Is it rapidly or is it insidious
in terms of progression?
Insidious.
02:38
It takes time, right?
But here, we have rapidly
progressive dementia.
02:43
It should clue you in.
02:44
Oh, my goodness, does my patient
have Creutzfield-Jakob?
Seventh decade is the peak.
02:50
Iatrogenic transmissible
is possible.
02:54
Subtle changes in memory and behavior
followed by rapidly progressive dementia
with involuntary
jerking movement.
03:00
Clinical presentation of
Creutzfield-Jakob disease.
03:05
We do have variants.
03:07
And we have
Gerstmann–Sträussler–Scheinker syndrome.
03:10
Inherited disease.
03:12
Progressive dementia with cerebellar
ataxia, just a couple of words
just so that you’ve heard
of such as prion disease.
03:18
Not commonly asked, but still
know that it exists, please.
03:22
Let’s do diagnosis of
our prion disease.
03:25
Difficult.
03:26
Imaging with our MRI with
diffusion-weighted image
CSF, this is important.
03:32
Memorize 14-3-3 protein.
03:34
There has to be something
that’s been given to you
in a stem of a question or clinically
in which you are seriously
suspecting a prion disease.
03:42
Please memorize 14-3-3 protein
in cerebrospinal fluid.
03:47
And you might find abnormal EEG
changes, electroencephalogram.