Higher Order Flashcards
Majority of brain surface is
Association Cortez
Two types of association cortex
Unimodal
Heteromodal
Unimodal association cortex
Input from primary sensory cortex of SPECIFIC MODALITY
Heteromodal association cortex
HIGHEST ORDER MENTAL FUNCTIONS
Bidirectional connect w/ both motor and sensory association cortex of all modalities and w/ limbic cortex
Left hemisphere functions
Praxis
Language
Arithmetic ability
Praxis
Skilled motor tasks
Lesion of dominant hemisphere—apraxia
Language
Left hemisphere
Certain areas of temporal (post wernicke’s) often 50% larger in left
Lesion to left language area— language dysnfction in left handed individuals
Right hemisphere function
Visual-spatial analysis and spatial attention
Prosody (imparting emotional sig to language - tone, rhythm, etc)
Musical ability
What happens when we hear a word and then repeat it aloud?
Auditory info to primary auditory cortex —>comprehended in werknicke’s —>transfer of info to broca’s
Communicate w/ each other via arcuate fasciculus
Broca’s area
Motor programming of speech
Formulates sequences of sounds
Activates nearby oral area of PMC
Words converted back to sounds
Broca’s connects w/
Prefrontal and premotor cortex and supplementary motor areas —correct syntax
Wernicke’s connects w/
Supramarginal and angular gyrus of parietal lobe, temporal lobe — correct lexicon
Reading
Visual info to PVC—> processed in visual association cortex —> travels ant to reach wernicke’s
Non dominant hemisphere contribution to language
Recognition and production of affective elements of speech
Lesion — difficulty in judging intended expression by tone of others voice, difficulty in producing emotionally appropriate expression in one’s own voice
Aphasia
Impairment of language
Dysfunction of dominant hemisphere
Spoken and written affected
Dysarthria
Impaired speech - mechanism for speech damaged
Caused by lesion in CB tract, CN nuclei/nerves V, VII, IX, X, XII, cerebellum, BG, muscles involved in speech production
Broca’s aphasia
Lesion to broca’s and adjacent structures in dominant frontal lobe
Impaired language production - perch is slow, telegraphic, writing/reading aloud also slow
Common etiology - broca’s aphasia
Infarct of L MCA superior division
Wernicke’s aphasia
Lesion of wernicke and adjacent structures in dominant temporoparietal lobe
Impaired language comprehension - speech is meaningless and nonsensical areas
Writing/reading out loud also fluent but meaningless paraphasic errors
Production relatively intact
Global aphasia
Impaired fluency
Impaired comprehension
Impaired repetition
Most common etiology - wernicke’s aphasia
Infarct of L MCA inferior division
Most common etiology - global aphasia
large L MCA infarct - includes superior and inferior division
Anomia
Difficulty in recalling names/words
Normal fluency, comprehension, repetition w/ naming difficulties and occasional paraphasias
Naming is often first function to be impaired and often last function to recover in language disorders
Apraxia (ideomotor)
Disconnect exists b/n idea of movement and motor execution —inability to carry out an action in response to verbal command, despite intact comprehension, motor/sensory pathways, coordination
1/3 of pts w/ aphasia have
Some aparaxia
Ideomotor apraxia usually caused by
Lesion of left frontal association cortex, particularly the premotor cortex and supplemental motor areas
Normal spatial attention
Left hemisphere responds to stimuli on right, right responses to stim on left
Right hemisphere responds strongly to both left and right sided stim, resulting in very slight left attention bias
Right hemi lesion (spatial attention)
Left is still able to attend to right sided stim, but there is SEVERE DEFICIT IN ATTENTION TO LEFT STIDED STIM
Left hemi lesion (spatial awareness)
Right hemi still attend to right sided stim —> minimal/ no deficit in attention to right sided stim
Spatial analysis - parietal association cortex
Junction of parietal, temporal, occipital lobes — dorsal stream (where) which analyzies location and motion of visual objects in space
Lesion of right parietal association cortex
Cause problems w/ spatial analysis
Hemineglect - lesion
Right parietal or right frontal cortex
Hemineglect
Profound neglect for contralateral half of external world, sometimes for the contralateral half of the body
Commonly accompanied by anosognosia
Munch more pronounced and last longer w/ right hemi lesion
W/ large strokes, recovery can take weeks to over
Anosognosia
Lack of awareness of the illness or that anything is wrong
Indications of hemineglect
Bumping into objects on one side Prone to injuries on one side Ignoring food on one side of plate Grooming one side of face/body Lack of movement of unilateral limbs Unaware of deficits
Sensory neglect
Hemineglect — ignore sensory stim in contralateral hemisphere.
Tactile neglect most common
Motor-intentional neglect
Hemineglect — no movement or fewer movements in contralateral hemi
Combined sensory and motor neglect
Hemineglect - pen and paper test
Conceptual neglect
Hemineglect - internal representations of own bodies or of external world exhibit contralateral hemineglect.
Anosognosia
right hemi lesions May also cause
Anosodiopharoia
Hemisamtognosis - deny half their body belongs to them
Agnosia
Sensory association cortex
Inability to recognize objects when using a specific sense, even through the primary sensory cortex is intact
Common w/ R hemi lesion
Asterognosis
Visual agnosia
Auditory agnosia
Astereognosis
Inability to recognize objects by tough and manipulation
Visual agnosia
Inability to recognized objects by vision
Auditory agnosia
Inability to recognize types of sounds
Problems commonly seen w/ R hemi brain damage
Anosognosia - overestimate ability, impulsive, poor judgement
Hemineglect
Agnosia
Mania/euphoria
Frequent mood changes
Problems commonly seen w L hemi brain damage
Aware of deficit (realistic, cautious, slow and hesitant behavior, anxious)
Aphasia
Apraxia
Depression
Disorganized
Frontal lobe functions
- Restraint (inhibition of inappropriate behaviors)
- Initiative (motivation to pursue positive/productive activities)
- Order (correctly perform sequencing tasks and a variet of other cognitive operations)
Prefrontal cortex
Largest part of frontal lobe - higher order heteromodal
Many bidirectional connections for higher order processing
Carry out function of goal oriented behaviors
Micturition inhibitory area
Signals (via BS and sacral cord) to dethrone to prevent bladder from contracting
Prefrontal cortex connections include
Association cortex from all lobes
PMC, supp motor areas and limbic cortex
Amygdala and hippocampal formation
Frontal lobe dysfunction evidence
History - fam/others who have seen pts behavior
Behavior abnormalities
Mental status (attention and memory testing, perseveration. Word generation, abstract reasoning, judgement)
Frontal release signs
Frontal gait abnormalities
Behavior abnormalities w/ frontal lobe dysfunctions
Abulia Disinhibition Inappropriate jocularity Limited insight and cofabulation Utilizing behavior Incontience w/ unconcern
Inferior occipitotemporal cortex
Processes color and form involved in object ID and recognition
Specialized regions involved in recognizing faces, numbers, letters ratings, colors
Prosopagnosia
Inability to recognize people by looking at their faces
Pts can ID people by their clothes or voice
Lesion causing prosopagnosis
Inferior occiptiotemporal cortex R>L
One of the most common causes for neuro consultation is
acute change in mental status
Most common cause: toxic or metabolic disturbances of the brain
