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
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
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
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
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