Higher Order Cerebral Function Flashcards
what is the difference between unimodal and heteromodal corticies?
both are association corties
unimodal are modality specific
heteromodal are higher-order functioning
what is one reason for hemispheric specialization?
a reduction in the amount of time it would take to have both hemisphere’s “talk to each other” to accomplish the task
T/F: there is bilateral representation of language centers in many right handers?
FALSE
it is observed in 60-70% of LEFT handers
what is our non-dominant hemisphere primarily responsible for?
- complex visual-spatial skills
- imparting emotional significance to events and language
- music perception
List some clinical features of a non-dominant hemisphere lesion
- visual-spatial analysis/constructional difficulties
- Gestalt difficulties
- tendency toward relatively severe personality and emotional changes
- increased likelihood to have delusions and hallucinations (when compared to the dominant hemisphere)
what is meant by constructional difficulties?
difficulty judging or matching orientation of lines displayed at different angles
(this person would have a hard time drawing more complex shapes but could draw simple ones)
what are gestalt difficuties?
overall spatial arrangement difficulties
(a pt would have difficulty understanding how everything is organized in their visual field, ie. big picture)
List some odd nondominant syndromes
- capgas syndrome
- fregoli syndrome
- reduplicative paramnesia
what is capgas syndrome?
patient insists that their friends and family members have been replaced by identical-looking imposters
what is fregoli syndrome?
patients belive that different people are actually the same person in disguise
what is reduplicative paramnesia?
patient believes that a person, place, or object exists as two identical copies
List some dominant (usually left) hemisphere functions
- Language
- skilled motor function (praxis)
- Arithmetic: sequential and analytical calculating skills
- Musical ability: sequential and analytical skills in trained muscians
- Sense of directions: following a set of written directions in sequence
List some non-dominant (usually right) hemisphere functions
- Prosody (emotion conveyed by tone of voice)
- visual-spatial analysis and spatial attention
- arithmetic: ability to estimate quantity and to correctly line up columns of numbers on the page
- musical ability: in untrained musicians, and for complex musical pieces in trained musicians
- sense of direction: finding one’s way by overall sense of spatial orientation
how do Broca’s and Wernicke’s area communicate?
arcuate fasciculus
List all the regions of the brain associated with language
- inferior lateral primary motor cortex
- Frontal lobes
- supramarginal gyrus and angular gyrus
- visual cortex, visual association cortex
- Non-dominant hemisphere is also involved
- subcotical regions
what is the role of the Frontal Lobe with respect to language processing?
- higher-order motor aspects of speech formation and planning
- syntax
what is the role of the supramarginal and angular gyrus (parietal and tempral lobes) in language?
- lexicon
- writing
what is the role of the visual and visual association cortices in language?
reading
List some syndromes related to aphasia
- Alexia
- Agraphia
- Alexia with agraphia
what is alexia?
an impairment in reading ability
what is agraphia?
impairment in writing ability
alexia without aphasia will have a lesion where?
dominant occipital cortex extending to the posterior corpus callosum (often PCA infarct)
Agraphia without aphasia will often involve a lesion where?
lesion of inferior parietal lobule of language-dominant hemisphere
what is alexia with agraphia?
what regions of the brain does it impact?
aphasia absent or only mild dysnomia and paraphasias
lesions of dominant inferior parietal lobe, region of angular gyrus
what are the symptoms of gerstmann’s syndrome?
- agraphia
- acalculia
- R/L disorientation
- Finger agnosia
a lesion to what region of the brain often results in gerstmann’s syndrome?
dominant inferior parietal lobe
(right where the angular gyrus is)
List some disorders involving the primary visual cortex
- Cortical blindness
- Blindsight
- Anton’s Syndrome
What is cortical blindness?
complete visual loss on confrontation testing
bilateral occiptial lobe lesion
what is blindsight and what causes it?
individual can perform a task without conscious visual perception
visual cortex lesion
What is Anton’s Syndrome? What causes it?
Complete visual loss on confrontation testing + anosognosia
Bilateral occipital lobe lesion
List some disorders involving the Inferior Occipitotemporal Cortex
- Prosopagnosia
- Achromatopsia
- Micropsia, Macropsia
- Metamorphopsia
- Cerebral dipopia/polyopia
what is archromatopsia?
Difficulty with color perception
whole visual field involved = lesions in bilateral inferior occititotemporal cortex
one eye = contralateral cortical involvement
what is micropsia and macropsia?
objects appear unusually small or big
what is metamorphopsia?
objects have distorted shape or size
what causes cerebral diplopsia/polyopia?
occipital lobe lesion
List some syndromes of the Dorsolateral Parieto-Occipital Cortex
- Simultanagnosia
- Optic ataxia
- ocular apraxia
- Baliant’s syndrome
what is simultanagnosia?
impaired ability to percieve parts of a visual scene as a whole
what is optic ataxia?
impaired ability to reach for or point to objects in space under visual guidance
what is occular apraxia?
difficulty voluntarily directing one’s gaze towards objects in peripheral vision
what is Baliant’s syndrome?
bilateral lesions of DL parieto-occipital cortex
presents with a clincial triad of the following symptoms:
- simultanagnosia
- optic apraxia
- occular apraxia
Functions of the frontal lobe can fit into 3 categories, what are they?
- restraint
- initiative
- order
list some restraint functions of the frontal lobe
- judgement
- foresight
- perseverance
- delaying gratification
- inhibiting socially inappropriate responses
- self-governance
- concentration
List some initiative functions of the frontal lobe
- curiosity
- spontaneity
- motivation
- drive
- creativity
- shifting cognitive set
- mental flexibility
- personality
list some Order functions of the frontal lobe
- abstract reasoning
- working memory
- perspective taking
- planning
- insight
- organization
- sequencing
- temporal order
what is the difference in symptoms between a dorsolateral and ventromedial orbitofrontal lesion?
DL = apthetic, abulic
VM = impulsive, disinhibited, poor judgement
what is the difference between a L and R hemisphere frontal lobe lesion?
left = associated with depression-like symptoms
right = more associated with behavioral disturbances like mania
frontal lobe syndromes are also known as ________________
dysexecutive syndrome
What types of symptoms are typically observed with an orbitofrontal lobe syndrome?
(disinhibited)
- impulsive behavior (psuedopsychopathic)
- inappropriate jocular affect, euphoria
- emotional lability
- poor judgement and insight
- distractibility
what types of symptoms are typically observed with frontal convexity syndrome?
(apathetic)
- apathy (pseudodepressive)
- indifference
- psychomotor retardation
- motor perseveration and impersistence
- stimulus-bound behavior
- motor programming deficits
- poor word list generation
What are some additional frontal lobe lesion symptoms?
- disinhibition
- inappropriate jocularity (witzelsucht)
- limited insight
- utilization behavior/environmental dependence
- frontal release signs
- paratonia
- frontal gait
what is the symptom of disinhibition?
silly behavior, crass jokes, aggressive outbursts
define inappropriate joculatiry (witzelsucht)
seemingly unconcerned about potentially serious matters
what is utilization behavior/environmental dependence?
respond to whatever stimuli at hand, even when not appropriate
(also called new bed over syndrome)
List some frontal release signs
- palmar reflex
- grasp reflex
- sucking reflex
what is paratonia?
increase in tone, but in a manner in which patient appears to resist the movements of the examiner in almost a willful fashion
define Frontal gait
shuffling, unsteady, magnetic gait
