Term
| What are the two kinds of cortex? |
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Definition
-90% is *neocortex, which has six cell layers
-Rest is *allocortex, which has three layers
-Allocortex is comprised of the olfactory cortex and the hippocampal formation |
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Term
| What are the cell layers? Which are more prominent for sensory vs. motor |
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Definition
-External GP, then internal GP, surrounded by two Ms;
1. Molecular layer
2. Ext. granular layer
3. Ext. pyramidal layer
4. Int. granular layer
5. Int. pyramidal layer
6. Multiform layer
-Pyramidal has motor projections (esp. internal)
-Granular has sensory projections (esp. internal) |
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Term
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Definition
| -The line that the int. granular cell layer forms in the primary visual cortex |
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Term
| Which hemisphere has more language control? |
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Definition
-The left
-Same with hand control (more people are right handed)
-The two seem to have a connection with each other |
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Term
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Definition
-The area is just lat. to the longitudinal fissure where the ant. and middle cerebral arteries meet up (poor supply)
-From low BP resulting in ischemia (CHF, etc.)
-Will involve the trunk more than anything (see homunculus) |
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Term
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Definition
-Involve deep penetrating arteries of proximal parts of larger arteries
-From hypertension
-Affect the deep structures |
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Term
| What does MCA supply? What do we see in occlusion? |
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Definition
-Lat. cortex (with all language areas and Meyer's loop)
-Posterior limb and genu of internal capsule
-Most of the basal ganglia
POSSIBLE DEFICITS;
-Spastic paresis of the contra. lower face and *upper limb
-Pie in the sky
Left;
-Aphasia's (Broca, Wernicke, global, or conduction)
-Gerstmann syndrome
Right;
-Unilateral neglect syndrome
-Dysprosodias (sensory or motor) |
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Term
| Expressive aphasia? Location and symptoms? Lesion on the right side? |
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Definition
-Aka Broca's aphasia
-From lesion of Broca's area (44 & 45); just below and in front of the motor cortex (communicates with)
-Causes broken speech where patients can understand, but not express (language to motor blocked)
-Also can't write (**same for all aphasias; means speechlessness from greek)
-Patients are aware and frustrated
Right Sided Lesion;
-Dysprosodia (motor); inability to put emotion into speech, although it is understood |
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Term
| Receptive aphasia? Location and symptoms? Lesion on the right side? |
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Definition
-Aka Wernicke's aphasia
-Lesion to Wernicke's area (22) at the base of the temporal lobe (next to and comm with the 1˚ auditory cortex)
-Cannot understand spoken language, and sometimes written language depending on the extent (angular)
-Patients can speak, but in a "word salad"
-They are unaware and show no distress
Right Sided Lesion;
-Dysprosodia (sensory); inability to understand emotion of speech, although they can speak with emotion |
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Term
| Gerstmann Syndrome? What happens on other side? |
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Definition
-Lesion of angular gyrus (area 39) next to Wernicke's (also next to and comm with visual ass. cortex)
-**Alexia & agraphia (can't read or write), but spoken may be understood if angular only
-*Right-left disorientation (will raise wrong hand)
-**Finger agnosia (can't recognize fingers)
-Acalculia
Right Sided Lesion (Spacial perception area);
-*Unilateral neglect; don't recognize **left world
-Can ask them to bisect a line or number a clock face
-Will be unaware of deficit
-Aka *asomatognosia |
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Term
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Definition
-From lesion to the superior longitudinal fasciculus (arcuate fasciculus) which connects Wernike's and the angular gyrus (comprehension) to Broca's area (motor)
-Verbal output is fluent, but with *paraphrases
-**Cannot repeat words or execute verbal commands
-Aware and frustrated
-A disconnect type syndrome where it is back to front |
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Term
| Frontal eye field lesion? |
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Definition
-Paralysis of voluntary contralateral horizontal gaze
-Will look toward side of lesion
-In front of motor cortex, so may also have contra. spastic paresis with eyes looking away from paralyzed limbs
-Still in MCA territory |
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Term
| What does ACA supply? Lesions? |
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Definition
-Med. surfaces of hemispheres
-Ant. majority of internal capsule (except splenium)
-Ant. limb of internal capsule
LESIONS
-Contralateral spastic paresis of lower limb (possible urinary incontinence, mostly if bilateral damage)
-Transcortical apraxia
-Pie on the ground (with aneurism) |
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Term
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Definition
-From lesion of ant. bulk of corpus callosum
-Disconnect syndrome where language info can't make it from left to right brain
-Patient can raise right, but not *left arm when asked to, although there is no paralysis
-If phone rings they can pick it up with the left arm
-Will not be able to read things in left visual field, but can draw it on paper when asked |
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Term
| Int. carotid aneurisms in the sinus? |
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Definition
-If it goes med., you get ipsi. loss of nasal field
-If it goes lat., you get ipsi compression of 6th nerve (causing med. strabismus) |
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Term
| What are the most common points of aneurism in the circle? Result |
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Definition
1. Ant. communicating at junction-->can cause pie in sky (similar to craniopharyngioma)
2. Post. comm.-->3rd nerve palsy |
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Term
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Definition
-Occipital lobe
-Lower temporal lobe
-Splenium of corpus callosum
-Midbrain
Lesions;
-Contralateral homonomous hemianopsia with macular sparing
-*Alexia without agraphia (can write but not read); left side only |
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Term
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Definition
-Caused by lesion to the spenium through which visual language info flows; from blockage of **LPCA only
-Will be accompanied by loss of contra. visual field
-Visual info gets to right brain fine, but then can't make it to language centers in left brain |
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Term
| What supplies the internal capsule and corpus callosum? Lesions? |
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Definition
Internal capsule;
-ACA, MCA, & MCA (see chart on 466)
Corpus callosum;
-Ant. 4/5; ACA-->transcortical apraxia
-Splenium; PCA-->Alexia without agraphia |
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Term
| "Cone stream" and "rod stream" location and lesions? |
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Definition
-Both are parts of visual association cortex with diffuse location in "rear brain" (mostly occipital)
-Connected to strait cortex (1˚ visual) and integrate info
Cone stream (form and color);
-*Parvocellular-blob zones in striate project to *areas 20 and 21 on underside of temporal lobe
-Lesions give *color blindness in contra half
-**Visual agnosia-->can't recognize objects
-**Prosopagnosia-->can't recognize faces (if lesion to adjacent occipital cortex)
Rod stream (motion);
-Uses *magnocellular system which projects from striate cortex (17) to 18 & 19 in parietal lobe (visual ass. cortex)
-Lesion results in inability to perceive motion |
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Term
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Definition
-Apraxia; disruption of patterning and execution of learned movements without weakness
-Patients can't perform movements in correct sequence |
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Term
| Prefrontal cortex damage? |
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Definition
Frontal lobe syndrome;
-Apathy
-Can't concentrate and are distracted easily
-Infantile reflexes (suckling and grasp reflexes) |
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Term
| What do we see with posterior parietal association cortex lesions? |
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Definition
-Similar to premotor damage, we see bilateral **apraxia
-Also see **astereognosia; can't recognize objects by touch, but can describe them (not sensory deficit)
-Usually from left hem. damage and gives only *contralateral deficit |
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