Lecture 3 Flashcards
primary motor cortex location
frontal lobe, precentral gyrus located along lateral and medial surface, brodmann’s area 4
lateral region of area 4 = UE, head/face, neck
medial region of area 4 = LE/trunk
primary motor cortex function
activates/controls voluntary fine motor movement of contralateral side of the body “right pmc controls left side of body”
primary motor cortex blood supply
lateral region = superior branch of MCA
medial region = ACA
primary motor cortex lesion
patient may experience contralateral hemiplegia/paresis - loss of voluntary fine motor movement on one side of the body, inability to activate muscles needed for movement, motor loss is most prominent in the distal extremities
primary motor cortex loss between ACA and
superior MCA stroke
superior MCA lesion =contralateral hemiplegia of lower face and UE
ACA lesion = contralateral hemiplegia of LE
premotor cortex location
frontal lobe, lateral region of area 6
premotor cortex function
plans complex voluntary fine motor movements and sends motor plans to the primary motor area for activation, planning is based on integrating current sensory information
premotor cortex blood supply
superior branch of MCA
premotor cortex lesion
patient may experience apraxia, patient is unable to perform learned skilled voluntary movements when asked, the loss is not caused by weakness, paralysis, or lack of coordination, caused by inability to generate and send the plan/sequence to motor cortex for activation or to understand the concept
supplementary motor area location
frontal lobe, superior/medial region of area 6
supplementary motor area function
plans(visualization) complex sequences of voluntary fine motor movements, planning is based on previous memories of learned movement sequences, SMA communicates with cerebellum to visualize the exact sequencing of muscles that will be needed to perform the action
supplementary motor area blood supply
ACA
supplementary motor area lesion
patient may experience incontinence, damage to micturition center, incontinence is expected finding of a stroke involving the ACA
frontal eye field location
frontal lobe, brodmann’s area 8
frontal eye field function
horizontal conjugate gaze/eye movements to opposite direction, the left FEF coordinates horizontal gaze to the right
frontal eye field blood supply
superior branch of MCA
frontal eye field lesion
patient may experience horizontal gaze palsy where eyes cannot look to the side opposite to the lesion, eyes deviate to the same side (ipsilateral) of lesion
brodmann area 44/45 dominant hemisphere
Broca’s area
brodmann area 44/45 non-dominant hemisphere function
motor production of the non-linguistic components of verbal communication, variations in tone/pitch, rhythm, production of the emotional aspect of language
posterior association area location
parietal lobe, brodmann areas 39,40, 7
temporal lobe, lateral/inferior temporal lobes
posterior association area dominant hemisphere function
higher order understanding (interpret & analyze) of sensory information, understanding communication linguistic (verbal, reading, braille), direction attention (directs attention to future or past tasks/events), understanding spatial relationships(processing right-left orientation), thinking/analysis (deductive reasoning, sequencing processes, mathematical, logical
posterior association area blood supply
MCA inferior branch
posterior association area dominant hemisphere lesion
agraphia = inability to communicate through writing
alexia or acquired dyslexia = inability or difficulty in reading due to inability to recognize letters/words
Wernicke’s aphasia = verbal
apraxia
difficulty directing attention on past or future tasks, impaired right-left orientation, finger/toe agnosia, loss of linear thinking, convergent problem solving, deductive reasoning
alcalculia = inability to perform calculations
anterior association area location
anterior region of the frontal lobe
Brodmann areas 9-11, 46, 47
consists of medial prefrontal cortex, ventral prefrontal cortex, lateral prefrontal cortex
anterior association area function
emotions and moods, self awareness, motivation, influence decision making to “act, how to act or not to act”
anterior association area blood supply
ACA = medial and ventral prefrontal cortex
MCA superior = lateral prefrontal cortex
anterior association area lesion
loss of emotion, self-awareness and motivation
dominant motor function
contralateral motor control of the body - right side of body
dominant somatosensory function
contralateral somatosensory sensation of the body - right side of body
dominant language communication
understanding/producing linguistic components of communication - actual semantic content of language - meaning of words/sentences, grammar
non-dominant motor function
contralateral motor control of the body - left side of body
non-dominant somatosensory function
contralateral somatosensory sensation of the body - left side of body
non-dominant language communication
understanding/producing non-linguistic components of communication: tone, pitch, pace, loudness, physical gestures - emotional aspect of language
apraxia
caused by damage from left parietal lobe, SMA, sub-cortical areas of the CNS (basal ganglia)
ideomotor apraxia
unable to perform action when asked but may randomly be able to perform the activity at a different time
ideational apraxia
unable to perform a sequential act even though can perform each part individually
SMA micturition
bladder control, one of many areas in the CNS that play a role in the control of micturition
Broca’s area blood supply
superior branch of MCA
Broca’s area function
motor production of the linguistic (language) components of communication, semantic content (words, sentences) of languages, working memory for language = sounding out word in head prior to speaking it
Broca’s area lesion
Broca’s aphasia = can comprehend language but can’t speak, loss of the ability to produce the linguistic components of verbal communication, may respond with short sentences or sounds
wernicke’s aphasia
sensory, receptive, fluent
global aphasia
motor and sensory aphasia damage to both Broca’s and Wernicke’s areas and/or the pathways (connections) between the two Broca’s and Wernicke’s areas
brodmann areas 44/45 non-dominant hemisphere lesion
patient may experience motor dysprosodia, may speak in flat monotone manner
motor dysprosodia
loss in the ability to produce the normal variations in intonation, tone, pitch, rhythm, etc. of verbal communication
motor dysprosodia
lesion in area 44/45 of non-dominant hemisphere
sensory dysprosodia
lesion in posterior area 22 of non-dominant hemisphere
dominant hemisphere
hemisphere that contains the language loop, designed for linear thinking, linguistic component of communication, mathematics and calculations, logical deductive reasoning, pays attention to tasks that need doing or past events, distinguish between right and left side of the body
non-dominant hemisphere
non-linear or holistic thinking, non-linguistic component of communication, creativity, imagination, pays attention to being in the moment, spatial awareness in the immediate moment, gestalt “the big picture”
association area
responsible for higher order interpretation and response and many of the functional differences between dominant and non-dominant hemispheres
Gerstmann’s syndrome
lesion of the dominant hemisphere in posterior association area that spares linguistic comprehension of language
classic signs/symptoms:
acalculia = inability to do math
impaired right-left orientation
finger/toe agnosia = unable to identify each finger/toe
agraphia = inability to write
~ understanding of spoken language remains intact
posterior association area function non-dominant
understanding communication (non-linguistic, tone, gestures)
directing attention - being in the moment
understanding spatial relationships - where body and objects are in relation to environment
thinking/analysis - non-linear, artistic, divergent thinking
posterior association area lesion non-dominant
sensory dysprosodia = inability to understanding non-linguistic components of communication
difficulty understanding relationship between body and environment
constructional apraxia = inability to draw, build or assemble 3D objects
loss of creativity, non-linear thinking, divergent problem solving
left sided neglect = inability to explore or respond to stimuli on left side of body
anosognosia = lack of awareness that a deficit exists
ventral prefrontal cortex function
social behavior
ventral prefrontal cortex lesion
loss of appropriate social behavior “disinhibited social behavior”
lateral prefrontal cortex function
executive function/goal directed behavior, wisdom
- receives sensory information from posterior association area, medial prefrontal area, ventral prefrontal area, limbic system, and brainstem and hypothalamus
lateral prefrontal cortex lesion
loss of executive functions (goal directed behavior), loss of working memory, perseveration (stuck on one though, inability to change behavior after starting it)
akinetic mutism
rare bilateral frontal lobe lesion, conscious alert patient who retains ability to move/speak but fails to do so
akinesia = lack of movement
mutism = lack of speech
apathy = lack of interest, indifferent, apathy cause passiveness to interact (speak) or respond (move)
