Upcoming Events
Log In
Pricing
Free Trial

Neuroanatomy and Neurophysiology of the corpus striatum 1

HIDE
PrevNext

0:00

Let's talk about neuroanatomy and neurophysiology,

0:03

which includes the putamen

0:05

and the caudate nucleus,

0:07

which has a head that we see but also a body and

0:10

a tail that we currently are not following.

0:13

As we go lower,

0:14

we see the lower head of the caudate,

0:16

the lower aspect of the putamen,

0:18

the mid aspect of the head,

0:19

mid aspect of the putamen and the upper aspect of

0:22

the head and the upper aspect of the putamen.

0:25

These are separated by the anterior limb

0:27

of the internal capsule, the genu,

0:29

which blends imperceptibly unless you have iron

0:32

sensitive sequences with the inner and outer

0:35

aspect of the globus pallidus known as

0:38

GPI for inner and GPE for outer,

0:42

GPE for external outer and GPI for inner.

0:45

And these are associated with structures such as

0:49

the subthalamic nucleus which we see below

0:51

the anterior commissure.

0:53

Maybe if we go a little bit forward

0:55

a little more anterior,

0:57

still more of the subthalamic nucleus region

1:00

in here and the substantia nigra.

1:03

Now, the substantia nigra in this young individual

1:06

with tumor factive MS is nicely seen as a somewhat

1:10

darkened stripe. And in Parkinson's disease,

1:14

we're going to look for loss of this

1:16

stripe in the outer aspect of it,

1:18

the so-called swallow tail sign.

1:20

But another thing we like to do is separate out

1:22

the round, dark signal of the red nucleus,

1:25

which is right here from the region of the

1:28

substantia nigra by this stripe.

1:31

And when they bleed together,

1:33

this is usually a sign that something's wrong and

1:35

is actually considered one of the signs

1:38

of Parkinson's disease.

1:39

Now, according to the model of motor loops between the

1:42

basal ganglia thalamus and motor cortical areas,

1:45

GABAergic projections from the inner aspect of the

1:50

globus pallidus modulate activities of other

1:54

structures such as the motor

1:55

nuclei of the thalamus,

1:57

which facilitate movement through excitatory

2:01

glutaminergic projections to

2:03

the cortical motor areas,

2:05

including the premotor cortex and supplementary

2:08

motor area. So, let's take a look at those.

2:11

Most of you already know where the thalamus is.

2:13

It's right here.

2:14

It's a very large complex structure

2:16

with the pulvinar in the back.

2:18

But if we follow the cingulum or cingulate

2:21

sulcus around to the back,

2:23

it becomes the sulcus marginalis

2:26

or supramarginal sulcus.

2:28

Just anterior to that is an oblique-looking sulcus

2:31

and that delimits the motor cortex just in front of it.

2:35

So, this is the motor cortex right here.

2:38

We also mentioned the SMA or supplementary motor

2:41

cortex which is found in the midline.

2:44

That's right here.

2:45

It controls movement,

2:47

especially things like posture and coordination.

2:51

But it's also intimately involved in either

2:53

stimulating or suppressing intrinsic motions that

2:57

are controlled by other structures in the body.

2:59

Now, if we follow this structure out laterally,

3:02

it becomes the prefrontal cortex.

3:04

So, laterally prefrontal cortex in the midline,

3:08

supplementary motor cortex with the motor cortex

3:12

lying immediately behind it in front of

3:14

the region of the sulcus marginalis.

3:18

That's a quick anatomic summary of what's going

3:21

on along with some physiology in the brain.

Report

Description

Faculty

Stephen J Pomeranz, MD

Chief Medical Officer, ProScan Imaging. Founder, MRI Online

ProScan Imaging

Tags

Normal Anatomy

Neuroradiology

MRI

Brain

© 2024 Medality. All Rights Reserved.

Contact UsTerms of UsePrivacy Policy