Here, we’ll quickly take a look at a
condition known as Huntington’s disease.
Now, this is a disease
in which in genetics,
is a big deal.
It’s an inherited autosomal
With Huntington, the particular
gene is called huntingtin.
The -ton becomes a -tin or should I
say the -ton is affected by the -tin.
By that, we mean Huntington and
huntingtin is the protein.
When do you find this?
Well, perhaps, fourth or fifth
decade, but it all depends, right?
And by that I mean a father –
well, not my father,
but in general –
Well, actually, we don’t know.
My father died of very
And he did have movement
disorder and there was no doctor
that we were able to find
in the United States
that was able to
properly diagnose him.
But the point being is if by
chance he did have Huntington,
and he then acquired it let’s say in
the fifth or even the sixth decade,
when we say anticipation,
there’s every possibility
that I am going to then
develop it at a younger age.
Ever so often, I wonder
if you’ve noticed,
but I do actually watch my hands until you
see as to whether or not I have tremors.
I know there’s something genetic
going on, it’s interesting.
Know thyself and know family
history so that you can
do the best that you can
in terms of prevention.
With Huntington, there might be
choreiform type of movement.
This chorea of
course means what?
It’s involuntary jerking
movement that’s taking place
in a flow-like manner from
one body part to another.
“I am flowing.”
You see this?
This is choreiform
type of movement.
Personality and behavioral
changes are something
that you would find
initially in your patient.
I will have to say for myself
that I do have mood disorders,
but not so sure if that has
anything to do with anything.
Progressive dementia is also a component.
May develop parkinsonism with
bradykinesia and rigidity later.
Remember, this is all related.
You’re down in the basal
ganglia, aren’t you?
And, you know, who’s to say that
it’s not going to overlap into --
or overlap with other symptoms
from other neurologic diseases?
Very high rate of suicide even if the
patient’s asymptomatic because up here,
you’re not quite sure as
what they’re thinking.
Death occurs 10 to 20
years after the onset.
Loss of your striatal inhibitory
output to the basal ganglia.
Remember, you have excess movement,
this is a hyperkinetic disorder.
And Huntington’s disease, you must know the
chromosome and its involvement will be 4.
We talked about the
trinucleotide, which is CAG.
You have to memorize CAG
if you haven’t already.
Know a few of these.
Another one that we’ve talked about
in greater detail has been CTG,
your myotonic dystrophy.
The protein or aggregate.
This protein is known as huntingtin.
T-I-N, please know that.
And there will be apoptosis taking place
of the neurons in Huntington’s disease.
Gross examination of your
brain with Huntington,
is that there will be
atrophy taking place.
So there is going to be a
small brain, but really,
you’re going to be focusing upon
atrophy taking place down subcortical
in the basal ganglia including the
caudate nucleus in the putamen
Resulting in what’s known as a box
car ventricle in a coronal MRI.
So if you do coronal
MRI, think about that,
and then you have an appearance of what’s
known as a box-car type of appearance.
Because the basal ganglia
is undergoing atrophy.
Microscopically, you could expect there to
be severe loss of your striatal neurons.
The treatment of choice for the chorea
is tetrabenazine, even as its mechanism
of action is unknown.
Keep in mind there might be side effects
such as depression and even suicide attempts.
There is a partial efficacy
of acetylcholinesterase inhibitors
to treat the dementia.
For the psychological issues
you need a multidisciplinary approach,
neuroleptics, and GABA agonists
are partially effective.