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. Inability 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 . We a k n e s s o f t h e r i g h t f a c e , a r m a n d l e g
• 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 of the right 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. Inability to see the right side of the world
http://en.wikipedia.org/wiki/Visual_field
Major Functions of the Cortex
The Visual Pathways Right
Left
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. Deviation 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 Willis
Territory of Major Vessels
CT Angiography Brain
Where Do Cerebral Emboli Come From?
CT Angiography Neck
CT Angiography Neck