Clinical Application

Case History

• 57 year-old right-handed man presents with neck pain and the sudden onset of neurologic deficits.

• Key findings

– 1. Inability to speak but understands

– 2. Weakness of the right face, arm and leg

– 3. Numbness of the right face, arm, and leg

– 4. Inability to see the right side of the world

– 5. Deviation of the eyes to the left

1. Inabi l i ty to speak but understands

• Aphasia

– Loss of ability to produce or understand

language

• An asymmetric function of the brain

Medina LS, Radiology 2007

Neuroanatomy of Aphasia

1. Broca’s area:

Inability to

speak

2. Wernicke’s

area: Inabilty

to comprehend

MRI Brain

MRI Brain

1. Broca’s aphasia:

2. Weakness o f the r igh t face, arm and leg

• Weakness can result from injury to the…

– Brain

– Spinal Cord

– Peripheral Nerves or their cell bodies

– Neuromuscular Junctions

– Muscles

Upper and Lower Motor Neurons

Central Sulcus

The Homunculus

From the London Natural History Museum

The Corticospinal Tract

MRI Brain

1. Broca’s aphasia:

2. Weakness

3. Numbness o f the r igh t face, arm, and leg

• Two parallel systems mediating sensation

from the body

Posterior/Dorsal Column Pathway

Spinothalamic Pathway

The Homunculus

Spinothalamic Pathway

MRI Brain

1. Broca’s aphasia:

2. Weakness

3. Numbness

4. Inab i l i t y to see the r igh t s ide o f the wor ld

http://en.wikipedia.org/wiki/Visual_field

Major Functions of the Cortex

The Visual Pathways

Left Right

MRI Brain

1. Broca’s aphasia:

2. Weakness

3. Numbness

4. Visual loss

5. Deviation of the eyes to the left

• Each hemisphere is involved in moving the

eyes in the direction away from that

hemisphere

Left Gaze Deviation

5. Deviat ion of the eyes to the left

MRI Brain

1. Broca’s aphasia:

2. Weakness

3. Numbness

4. Visual loss

5. Gaze Deviation

MRI Brain

1. Broca’s aphasia:

2. Weakness

3. Numbness

4. Visual loss

5. Gaze Deviation

MRI Brain

MRI Brain

Vascular Supply to the Brain

Circle of Will is

Territory of Major Vessels

CT Angiography Brain

Where Do Cerebra l Embol i Come From?

CT Angiography Neck

CT Angiography Neck