CNS Unit 12 Flashcards
What are the 4 basis categories of function with the Limbic System?
“HOME”
- Homeostasis ; Hypothalamus
- Olfaction ; Olfactory cortex
- Memory ; Hippocampal formation
- Emotion ; Amygdala
Limbic System
What is the Function of Septal Nuclei? What would happen if there was a lesion here?
This is involved in pleasure center; moderate memory; responsible for desire to eat
- Lesions associated with anorexia, nervosa and gluttony
Limbic System
What is the function of the Thalamus? What would happen if there was a lesion here?
This deals with emotional response to sensation
- Korsakoff’s Syndrome: is caused by alcoholism or Vitamin B1 deficiency
Limbic System
What is the Function of the Hypothalamus? What would happen if there was a lesion here?
Mediates autonomic response to emotion - blushing ; Special nuclei modulates opposing function of the hypothalamus
- Lesions can cause Anorexia, Bulimia
Limbic Lobe
What would happen if there was a lesion to Pariaqueductal Gray (of brainstem)?
This leads to indifference to pain
Limbic System
With the Olfactory Cortex, what is the function of Rhinencephalon?
- Smell
-Odors of external environment
-Sensation to taste
With the Olfactory Cortex, what are secondary Olfactory areas?
- Anterior Entorhinal Cortex: Memory
- Orbitofrontal Olfactory Area: Smell discrimination
What is the Function of the Amygdala? What would a lesion here cause?
Function:
- Emotion
- Autonomic
- Neuroendocrine
Lesion:
- Flat affect
- Hypersexuality
- Disinhibited behavior
Where does the Amygala recieve input and take out the output?
Input:
- Sensory systems
- Mediodorsal thalamus
- Lat., Med. Hypothalamus
- Septal area
- Periaqueductal Gray
Output:
- Stria terminalis
- Ventral Amygdalofugal
Limbic System: Hippocampal Formation
What are the 2 regions for Memory Formation?
- Medial Temporal Lobe:
-Hippocampal Formation
-Parahippocampal Gyrus - Medial Diencephalic
-Mediodorsal and anterior thalamic nuclei
-Mammillary Bodies
-Diencephalic nuclei
What are the Classifications of Different Types of Cortex?
- Primary Motor or Sensory Cortex
- Unimodal Association Cortex: These deal with association that is modality specific
- Heteromodal Association Cortex
- Limbic Cortex
What is Cerebral Lateralization?
This is when certain functions tend to be lateralized or specialized in one hemisphere versus another
- Hemishperic Specialization eliminated the delay of long callosul transmission
Ex:
- Handedness: 90% of the population is right handed
- Language: L hemisphere is dominate for 95% of right handers adn 60-70% of left handers
- Perception: R hemisphere
This is not apparent until 3 to 4 years of age
With Cerebral Organization, which higher order functioning cortex will you find posteriorly? Whats the function?
- Posterior Parietal and Temporal Association Cortex
- This deals more with interpreting perceptual data and assigning meaning to sensory information
With Cerebral Organization, which higher order functioning cortex will you find anteriorly? Whats the function?
- Frontal Association Cortex (Prefrontal cortex)
- This deals more with planning, control, execution of actions
What are the Functions of the Dominant Hemisphere?
Usually Left Hemisphere
- Language
- Skilled Motor Formulation (Praxis)
- Musical Ability: sequential and analytical skills in trained musicians
- Arithmetic: Sequential and analytical calculating skills
- Sense of Direction: following a set of written directions in sequence
What are the Functions of the Non-Dominant Hemisphere?
Usually Right Hemisphere
- Prosody (emotion conveyed by tone of voice)
- Visual-spatial analysis and spatial attention
- Musical Ability: In untrained musicians, and for complex musical pieces in trained musicians
- Arithmetic: Ability to estimate quantity and to correctly line up columns of numbers on the page
- Sense of direction: Finding one’s way by overall sense of spatial orientation
L Hemisphere
How is information transferred between Broca’s Area and Wernicke’s Area?
By the Subcortical white matter pathway called the Arcuate Fasciculus
Sounds converted to words in Wernicke’s; and Words converted to sounds in Broca’s
What other areas work with Broca’s Area?
Other Anterior Areas, for higher-order motor aspects of speech forumlation and planning
- Premotor and Supplementary Motor Cortex (B.A 6)
- Prefronal Cortex (B.A 8, 9,10, 46,47)
This is where we get syntax or grammatical structure
Syntax: The arrangement of words and phrases to create well-formed sentences in a language
What other areas work with Wernicke’s Area?
More Posterior Areas, for language comprehension
- Inferior Temporal Language Area (B.A 37)
- Angular Gyrus (B.A 39); this is important for written gyrus
- Supramarginal Gyrus (B.A 40)
This is more about lexicon and its very important in mapping sounds to meaning
What is Aphasia?
- A defect in language processing
- Dysfunction of the Dominant cerebral hemisphere (typcially left)
- Spoken and written language is affected
What is Broca’s Aphasia?
AKA Non-Fluent Aphasia/Expressive Aphasia/Motor Aphasia/Anterior Aphasia
- Damage to Broca’s Area (B.A 44, 45)
- Most common lesion due to L MCA Superior Division Infarct
- Decreased fluency in language
- Naming difficulties
- Repetition is impaired
- Comprehension is INTACT
What ae Common Associated Features of Broca’s Aphasia?
- Dysarthria
- Right Hemiparesis
- Frustration
- Depression
- Sometimes apraxia on non-paretic left side
What is Wernicke’s Aphasia?
AKA Fluent Aphasia/Receptive Aphasia/Sensory Aphasia/Posterior Aphasia
- Damage to Wernicke’s Area (B.A 22) in dominant temporoparietal lobes
- Most common lesion due to L MCA Inferior Divisions Infarct
- Fluent speech, but its empty, its meaningless with nonsensical paraphasic error
- Naming difficulties
- Repetition is impaired
- Impaired Comprehension
What are Common Associated Features with Wernicke’s Aphasia?
- Contralateral Visual Field Cut (Optic Radiation Involvement)
- Patient unaware of their deficits
- Angry or paranoid behavior
- Apraxia may be present but difficult to diagnose
If there is a really large L MCA Infact, what type of Aphasia will be present?
Global Aphasia
- Language is not fluent
- Does not Comprehend
- Repetition is impaired
If there is a lesion/oculusion in the communication of Arcuate Fasciculus, what type of Aphasia will be present?
Conduction Aphasia
- Language is Fluent
- Can comprehend
- Repetition is impaired
Other Syndromes related to aphasia
What is Alexia?
Impaired Reading
Other Syndromes related to aphasia
What is Agraphia?
Impaired writting
Other Syndromes related to aphasia
What is Gerstmann Syndrome?
Agraphia, Acalculia, right-left disorientation, finger agnosia
Other Syndromes related to aphasia
What is Cortical Deafness?
Bilateral lesions of Heschel’s Gyrus, can’t interpret sound
Other Syndromes related to aphasia
What is Pure word deafness/Verbal Auditory Agnosia?
Cannot understand spoken words but understands nonverbal sounds (Dominant Hemisphere)
Other Syndromes related to aphasia
What is Nonverbal Auditory Agnosia?
Cannot understand nonverbal sounds but understands speech (non-dominant hemisphere)
Other Syndromes related to aphasia
What is Ideamotor Aphraxia?
The inability to carry out an action in response to a verbal command
Other Syndromes related to aphasia
What is Ideational Apraxia?
Inability to conceptualize, plan, execute motor actions
Other Syndromes related to aphasia
What is Aphemia?
Verbal Apraxia (normal written language)
Cannot put words together appropriately
With the Non-Dominant Hemisphere, what is Lateralized Attention?
This means that the nondominant hemisphere deals more with attention and perception
What would happen if there is a lesion to the Non-Dominant Hemisphere?
This leads to long-lasting deficits of neglect to contralateral side
What would happen if there is a lesion to the Dominant Hemisphere?
This leads to mild or undetectable neglect to contralateral side
What would happen if there is a lesion to the in both hemispheres (bilateral) Hemisphere?
This would cause severe neglect of the right side
With the Non-Dominant Hemisphere, what is Spatial Processing? What Gyrus are associated with this?
What would happen if there was a lesion here (Parietal association cortex)?
This is Visual-spatical analysis and perception
*This is where we visually analyze our environment, and perceive our environment)
- The 2 Gyrus are the Supramarginal Gyrus (B.A 40) and Angular Gyrus (B.A 30)
Issues with being able to navigate our environment and also perceive whats in it
What is Hemineglect Syndrome?
This is Neglect that can be:
- Sensory Neglect
- Motor-Intensional Neglect
- Combined Sensory and Motor Neglect
- Conceptual Nelgect
Hemineglect Syndrome
What is Sensory neglect?
The Patient ingores visual, tactile, auditory stimuli
Hemineglect Syndrome
What is Motor-Intensional Neglect?
Patient perform fewer movements in contralateral space
Hemineglect Syndrome
What is Conceptual Neglect?
- The Patient’s internal representation of their own bodies or the environment exhibit contralateral hemineglect
- Anosognosia
More severe form of neglect
What are some Clinical Features of Nondominant Hemisphere Lesions?
- Difficulty with Visual-Spatial Tasks
- Difficulty with constructional ability
- Severe personality or emontional changes
- Impaired geographic orientation
What is Capgras Syndrome?
When the Patient insist friends and family have been replaced with identical looking imposters
What is Fregoli Syndrome?
These patients believe different people are actually the same person in disguise
What is Reduplicative Paramnesia?
These patients believe that a person, place or thing exist as two identical copies
What are the Functions of the Frontal Lobe that deal with Restraint?
- Judgement
- Foresight
- Perseverance
- Delaying Gratification
- Self-governance
- Concentration
What are the Functions of the Frontal Lobe that deal with Initiative?
- Curiosity
- Spontaneity
- Motivation
- Drive
- Mental Flexibility
- Personality
What are the Functions of the Frontal Lobe that deal with Order?
- Abstract reasoning
- Working meaning
- Perspective taking
- Planning
- Insight
- Organization
- Temporal Order
What are the Main Functional Areas of Frontal Cortex?
- Prefrontal Cortex (deals with executive function; largest part of frontal lobe; where high-order functioning occurs)
- Limbic Anterior Cingulate and Orbitofrontal cortex
What are some Functions of the Prefrontal Cortex?
- Attention span
- Motivation
- Problem-solving abilities
- Prognosticate
What are the Connections of the Prefrontal Cortex?
These connections are bidirectional and mainly with the parietal-occipital-temporal association cortex
Other connections:
- Limbic cortex
- Amygdala
- Hippocampal formation
- Thalamus
- Basal Ganglia
With the Frontal Lobe, what is the function of the Dorsolateral Prefrontal Cortex?
- Working Memory
- Learning new material
- Shifting cognition
- Selective cognition
- Emotional weighting of abstract decision making: intuition
With the Frontal Lobe, what is the function of the Orbitofrontal Lobe?
- Impulse control
- Judgement
- Social Appropriateness
In the Frontal Lobe, what would happen if there was a Lesion to the Dorsolateral Prefrontal Cortex?
Dorsolateral Convexity Lesions
- The patient would be apathetic, lifeless, in abulic state
In the Frontal Lobe, what would happen if there was a Lesion to the Orbitofrontal Lobe?
Ventromedial Orbitofrontal lesions
- The patient would be impulsive, have disinhibited behavior and poor judgement
Also:
- Minimal emotional response to pain
- Decreased motivational drive to participate in therapy
- IQ scores usually intact
What would happen if there was a lesion in the Inferior Temporal Pole?
- Learning Visual Task almost impossible
In the Frontal lobe, what may we see with Lateralization Lesions?
- Right Frontal Lesions:
-Behavioral Disturbances - Left Frontal Lesions:
-Depression-like symptoms
