NEU 409 Exam 3 Flashcards
Cerebral Vascular Accident (CVA, a.k.a. stroke):
Ischemic Stroke:
Thrombus vs. Embolus
Hemorrhagic Stroke:
Aneurysm, AVM
Functions Affected:
Ischemic Stroke: Blockage of blood vessels; lack of blood flow to affected area
Motor and sensory issue - contralateral - anterior artery supply
Types:
Thrombus(bloodclot) vs. Embolus(ball and hits arteries)
Hemorrhagic Stroke: Rupture of blood vessels; leakage of blood
Medial artery supply
Plaque caused by cholesterol
Aneurysm, AVM(arteriovenous malformation) - arteries blooming
born with aneurysm or AVM - a balloon/bulge and if grow then very bad
high-pressure blood flow causes the vessels to expand balloning
Functions Affected:
Speech,
Language
Hearing,
Swallowing
Motor function
Stroke Intervention(find stroke): symptoms stroke max 3 hours
Ischemia VS Aneurysm
Penumbral tissue:
CT scan to rule out hemorrhage(bursting blood clot can cause hemorrhage) (CT shows blood)
DWI and PWI - imaging looking at blood flow
No hemorrhage, treat ischemia(clot and no blood)
- tPA injection
- Surgical clot removal (endovascular surgery)
Aneurysm treatment
Clipping
Coiling
(tPA) Penumbral tissue:
Tissue at risk of being recruited into the ischemic core (i.e., brain cells that will die if they don’t receive blood very soon)
Traumatic Brain Injury (TBI):
Open VS Closed
Acute brain injury (ABI)
Coup Injury:
Contrecoup:
Blast Injuries: War
Primary:
Secondary:
Tertiary:
Quaternary:
TBI → Open Head Injury (blunt force or gunshot)
TBI → Closed Head Injury(car accident) → Either Acceleration-deceleration closed head injury OR Impact-based closed head injury
Acute brain injury (ABI) → caused by disease, blows to the head, alcohol and drug use, or oxygen deprivation.
Coup Injury: toward front of head
Contrecoup: toward back of head
Blast Injuries: War
Primary: Directly from the air compressions of the blast
Secondary: Injury from flying objects
Tertiary: Person pushed into another object
Quaternary: From blood loss or toxic gas
TBI Problems: Physical Issues
TBI Problems: Cognitive - Communication
TBI Problems: Physical
Coma
Drowsiness
Headache
Seizures
Hydrocephalus
Plegia/Paresis
Dyskinesias
Vision changes
Multiple traumas (e.g., blunt chest trauma)
TBI Problems: Cognitive - Communication
Attention
Orientation
Memory
New learning
Thought organization
Reasoning
Problem solving
Executive functions
Speech-language issues
What is Dementia?
Diagnostic Criteria:
Multiple cognitive deficits manifested as impairment
Mild cognitive impairment:
What is Dementia?
- Dementia is classified as a syndrome because it is characterized by a constellation of symptoms
- Dementia results from varied etiologies and has varied clinical presentations
- Memory, Attention, Critical thinking, Language
Diagnostic Criteria:
- Learning new information
- Recalling previously learned information
- Produce a significant impairment in the ability to function
- Represent a significant decline from previous functioning
- Aphasia, Apraxia, Agnosia
(failure to recognize or identify objects, sounds, or words despite intact sensory functions)
- Disturbance in executive functioning:
planning, organizing, sequencing, abstracting
Mild cognitive impairment:
Mostly doesn’t affect everyday activities
Some impact on memory, attention
inability to remember a word (amnesia) and the inability to understand a word (aphasia) or the inability to recognize a fork as a fork (agnosia) and the inability to use it properly (apraxia)
C-11 PIB (aka the “Pittsburgh Compound”):
Radiotracer used with PET scans (Carbon-11)
Images the build-up of beta-amyloid plaques in the brain - Associated with Alzheimer’s Disease and Dementia
Alzheimer’s - What goes first and Largest change
Alzheimer’s Disease:
Brains atrophy with neuronal loss, neurofibrillary tangles, and senile plaques:
What goes first is cognition and memory
Largest change from mid-end stage is self care
Alzheimer’s Disease:
Abnormal tissue changes in the brain - Pathologic changes occur in the association areas of parietal, temporal, and frontal lobes and in the hippocampus
Brains atrophy with neuronal loss, neurofibrillary tangles, and senile plaques:
- Plaques block neurotransmitter movement between cells
- Tangles disrupt the microtubules, which impacts transport of nutrients within cells
Forms Of Dementia:
Pattern of Brain Tissue Loss:
Alzheimer’s disease (most common, 50%)
Vascular dementia (2nd most common, 20%) - small strokes due to high blood pressure
Lewy Body Dementia (3rd most common, 10-25%)
Parkinson’s disease & Huntington’s Disease
Pattern of Brain Tissue Loss: Alzemeirs is temporal lobe and frontal dementia is temporal and frontal lobe
Vascular Dementia:
Small strokes due to high blood pressure
Due to vascular abnormalities including cerebrovascular disease, hypertension, and atherosclerosis.
Characterized by stepwise deterioration and focal neurological signs.
A person may acquire vascular dementia after sustaining large cerebral infarcts, ischemic events, and occlusion of fine capillaries in the cortex.
Lewy Body Dementia:
Occurs in more men than women
Abnormal protein deposits
Confusion, memory loss, hallucinations, tremors, muscle rigidity, problems with balance
Sort of a hybrid between Alzheimer’s and Parkinson’s
- Motor symptoms similar to PD
- Cognitive symptoms similar to AD
Fronto-Temporal Dementia:
These types of dementia are relatively rare (10%).
They usually have early onset (in the 40s and 50s)
associated with personality changes
(selfish, moody, unable to be empathic)
reduced language
difficulty executing complex tasks
Associated with Primary Progressive Aphasia - loss of ability to understand or express speech, caused by brain damage
Meningitis:
Encephalitis:
Neoplasm:
Meningitis: Inflammation of meninges
- Bacterial, Viral, Fungal
Encephalitis: Inflammation of the brain
- Most commonly viral
Neoplasm: Brain tumor
- Benging(not cancer), Malignant
Brain Tumor Grades (WHO):
Grade 1:
Grade 2:
Grade 3:
Grade 4:
Grade 1:
Least malignant tumors and are usually associated with long-term survival.
They grow slowly and have an almost normal appearance when viewed through a microscope.
Surgery alone may be an effective treatment for this grade tumor.
Grade 2:
These tumors are slow-growing and look slightly abnormal under a microscope.
Some can spread into nearby normal tissue and recur, sometimes as a higher grade tumor.
Grade 3:
These tumors are, by definition, malignant although there is not always a big difference between grade II and grade III tumors.
The cells of a grade III tumor are actively reproducing abnormal cells, which grow into nearby normal brain tissue.
These tumors tend to recur, often as a grade IV.
Grade 4:
These are the most malignant tumors.
They reproduce rapidly, can have a bizarre appearance when viewed under the microscope, and easily grow into nearby normal brain tissue.
These tumors form new blood vessels so they can maintain their rapid growth and have areas of dead cells in their centers.
Structural imaging:
Functional imaging:
Spatial Resolution: From Best to Worst
Temporal Resolution: From Best to Worst
Structural imaging: viewing the anatomy of the brain
Functional imaging: viewing the physiology of the brain while it functions
Spatial Resolution: From Best to Worst
1. fMRI
2. PET
3. Electrophysiological techniques
(EEG & MEG)
Temporal Resolution: From Best to Worst
1. Electrophysiological techniques
(EEG & MEG)
2. fMRI
3. PET
Structural Imaging: CT
Postitive:
Negative:
CT use in acute identification of stroke, most common
Not able to detect ischemic stroke for 1-2 days
Ideal for imaging structures/substances that will be radiopaque and show up as bright white on the image - Bones, Blood
NOT great for imaging soft tissues show up as variations of gray on image
Water/CSF shows up as black on image
Why is blood radiopaque when water isn’t? Iron and red color
Postitive:
Commonly used
Easily accessible
Inexpensive
Quick processing time
Ideal for imaging bony structures, detecting blood
Negative:
Use of X-rays/cancer risk
Shows structure only
Difficulty observing new damage
Clarity of images (difficulty seeing soft tissues)
Structural Imaging: MRI
How dangerous is metal in an MRI scanner?
Postitive:
Negative:
MRI = Magnetic Resonance Imaging
3-dimensional image produced
Strength of machine translates to the quality of the image
T = Tesla
3T strongest, clearest images, research & clinical
1.5T common for clinical use
Open MRI → 0.3 or 0.5 T–very weak magnetic field, produces very poor quality images
How dangerous is metal in an MRI scanner?
In an emergency, the magnet must be “quenched”
Sudden loss of superconductivity when temperature is raised
Deactivating the magnet releases massive amounts of boiling helium liquid, which is comes out as helium “steam”
Postitive:
Much better images
Images in multiple dimensions
No X-rays
No preparation needed (e.g., injections, etc.)
Negative:
More expensive than CT
Patients with metal in body
Patients must be still
Patients with claustrophobia will struggle with exam
MRI
Types of images
T1 VS T2
T1:
Measured
Typically good for depicting anatomic detail
Good contrast between gray and white matter
Water & Edema appear dark
Fat appears bright
Gray matter is dark gray; white matter is light gray
T2:
Sensitive to changes in water content
Better diagnostic tool for identifying edema (swelling) and ischemia (blockage)
Water is bright
Fat is gray
Gray matter is light gray; white matter is dark gray
Direct Comparison:
CT VS MRI
CT:
Less expensive
Faster to acquire images
5 min scan, 30 min exam, 30 min image processing
Not as sensitive to movement
Widely available
Metal implants and claustrophobia not an issue
Images are not as clear
Exposes patient to radiation
Ideal for showing blood in acute stroke
MRI:
More expensive
Takes longer to acquire images
30-45 min scan, 60 min exam, 30 min image processing
Very sensitive to movement
Not quite as widely available
Contraindicated for patients with metal implants or claustrophobia
Clearer images of anatomy
No radiation exposure
Can show ischemic areas before CT
Structural imaging: Diffusion-Weighted Imaging (DWI)
Structural imaging: Perfusion weighted imaging (PWI)
Diffusion MRI - Diffusion Tensor Imaging (DTI):
Structural Imaging: Cerebral Angiography
Administered using CT or MRI
Diffusion-weighted MRI (DWI) is sensitive in detecting infarcted brain tissue, whereas perfusion-weighted MRI (PWI) can detect brain perfusion in the same imaging session. Combining these methods may help in identifying the ischemic penumbra, which is an important concept in the hemodynamics of acute stroke.
Structural imaging: Diffusion-Weighted Imaging (DWI)
Magnetic fields in the MRI are pulsed, which allows measurement of water diffusion (movement) over time
Structural imaging: Perfusion weighted imaging (PWI)
MRI that requires injection of radioactive contrast medium (gadolinium)
Diffusion MRI - Diffusion Tensor Imaging (DTI):
Imaging white matter tracts
Measures the direction of water diffusion
Fractional anisotropy (FA) values closer to 1 indicate water movement in all directions, lower values indicate interruptions
Detecting disruptions in the white matter tracts
Structural Imaging: Cerebral Angiography
Administered using CT or MRI
- x-rays to see how blood flows through the brain. A carotid arteriogram is an X-ray study designed to determine if there is narrowing or other abnormality in the carotid artery, a main artery to the brain.
Spatial Resolution:
Temporal Resolution:
Spatial Resolution: location of brain activity when a stimulus is introduced
Temporal Resolution: time between when a stimulus is presented and the brain’s response to that stimulus
Functional Imaging: PET
PET = Positron Emission Tomography
Positives:
Negatives:
Can be acquired using same scanner as for CT (CT/PET combo machine common)
Radiotracer injected into patient
Scanner measures photons given off to produce image
Relatively good spatial resolution (about 1 cm)
Poor temporal resolution (over 1 minute)
Positives:
Good image of location of brain activity
Provides information about cellular function
Good for pre/post treatment to examine changes in function
Negatives:
Invasive procedure because of injection
Radioactive material used
More expensive technique than CT and MRI
Functional Imaging:
Electroencephalography (EEG)
Magnetoencephalography (MEG)
Commonly used for:
Positives:
Negatives:
Provides a graphic representation of the summated electrical activity in the brain
Place metal electrodes at different positions on the scalp
Electrical signal recorded from different areas of brain
Commonly used for:
Diagnosing seizures
Sometimes use techniques to evoke seizure
E.g., hyperventilation or sleep deprivation
Evaluating brain death
No response to external stimuli, cannot spontaneously breathe, no cranial nerve reflexes, flat line on EEG
Diagnosing sleep disorders
Measured in conjunction with other biological functions
E.g., heart rate, breathing
Positives:
Low cost
Readily available
Good information on brain function
Excellent temporal resolution (milliseconds)
Negatives:
The “image” produced does not show any structure
Functional Imaging: fMRI
fMRI = Functional Magnetic Resonance Imaging
Positives:
Negatives:
Blood Oxygenation Level Dependent (BOLD) signal
Delayed HRF (hemodynamic response function) in hypoperfused tissue
Positives:
Can see structural & function at the same time (with addition of structural MRI)
No radiation exposure
Excellent spatial resolution (mm)
Mid-level temporal resolution (seconds)
Negatives:
Expensive
Not widely available for clinical use
Takes a long time to acquire
Levels of Motor Speech System: 8
Conceptual
Planning
Motor programming
Motor control circuits
Direct motor pathway
Indirect motor pathway
Final common pathway
Sensory system
Come
People
My
Monkey
Dosent
Ignite
Fights
Slay
Conceptual Level:
Involves our thoughts, feelings, and ideas
Prefrontal cortex
Limbic system
Planning Level:
Involves 2 parts:
Language problem - Aphasia
Linguistic planning:
language content, form, and use (or semantics, grammar, and pragmatics), perisylvian region of left hemisphere
Motor planning: plans and arrangements of phonemes
Premotor cortex (BA 6) important area for planning
Aphasia: problem selecting the right word
Motor Programming Level:
Execution of phonemes in time & space
Involve discrete movements of tongue, lips, etc.
Cerebellum, basal ganglia, and supplementary motor area (BA 6) are important areas to programming
Direct Pathway:
a.k.a., pyramidal system
Involves lateral motor system—lateral corticobulbar and corticospinal LMN tracts
Function of pathway—voluntary motor movement of contralateral limbs/speech muscles → voluntary motor movement of contralateral limbs/speech muscles
Makes few stops
Crosses over (decussates) at medulla/spinal cord juncture
Corticobulbar vs. Corticospinal:
Start in motor cortex
End in either:
Brainstem (corticobulbar)
Send signals from brain to cranial nerves
OR
Spinal cord (corticospinal)
Send signals from brain to spinal cord
UMN vs LMN:
Direct Motor Pathway Damage:
UMN damage:
LMN damage:
Upper part of tract (brain and spinal cord) = Upper Motor Neurons (UMN)
Lower part of tract (cranial and spinal nerves) = Lower Motor Neurons (LMN)
Motor neurons in ventral horn of spinal cord
Command muscle contraction
UMN damage:
Spastic muscles
Hypertonia
Hyperreflexia (+ reflexes)
Clonus
(+) Babinski sign - reflex toe problem
No atrophy
No fasciculations
LMN damage:
Flaccid muscles
Hypotonic
Hyporeflexia (– reflexes)
No clonus
No Babinski sign
Marked atrophy
Fasciculations
Indirect () Motor System:
a.k.a., extrapyramidal system
Function - Posture, muscle tone for fine movement
Indirect pathway with many stops - Includes the medial motor systems:
Vestibulospinal
Reticulospinal
Tectospinal
Decussation = none (except for tectospinal)
Basal ganglia = the main center of this system
Speech Issues:
Damage to the pyramidal and/or extrapyramidal systems can lead to:
Damage to the basal ganglia control circuits can lead to:
Problem: ataxic dysarthria
Damage to the pyramidal and/or extrapyramidal systems can lead to:
Spastic dysarthria (UMN damage) - Harsh voice, monopitch, hypernasal, slow rate, imprecise consonants
Damage to the basal ganglia control circuits can lead to:
Hyperkinetic dysarthria (Huntington’s disease)
Harsh voice, monopitch, loud voice, imprecise consonants, distorted vowels
gaba not working
Hypokinetic dysarthria (Parkinson’s disease)
Stiff , rigid, slow movements
Breathy voice, monopitch, reduced syllable stress, variable speech rate, imprecise consonants
dopamine not working
ataxic dysarthria
Cerebellar lesion u sound drunk ataxia
Motor Control Circuits:
when this system is damaged -
Motor Control Circuits: Cerebellum
Basal Ganglia Includes caudate nucleus, putamen, globus pallidus, substantia nigra, and subthalamic nuclei
Regulates motor functioning especially tone and posture so that we have smooth, precise motor movements
Dyskinesias results when this system is damaged - involuntary, erratic, writhing movements of the face, arms, legs or trunk
Motor Control Circuits: Cerebellum
Coordinates muscle movements so that they are skilled and sequential
When damaged, speech can become uncoordinated, resulting in a condition known as ataxic dysarthria.
Information is sent to and from the cerebellum to accomplish this
Final Common Pathway (FCP):
FCP = last leg of a motor signal’s journey
Part of the lower motor neurons (LMNs)
Involves:
Alpha motor neurons - Muscle contraction
Gamma motor neurons - Proprioception
Cranial nerves
Types of Muscle Tissue:
Striated/skeletal:
Smooth:
Cardiac:
Striated/skeletal:
Muscles affecting skeletal movement
Usually under voluntary control
Smooth:
Contraction is slow and sustained
Under involuntary control
Cardiac:
Designed for endurance
Involuntary control
Alpha Motor Neurons:
- Initiate muscle contraction
- Muscle + neuron = motor unit
- All alpha motor neurons innervate single muscle = motor neuron pool
- Sustained contraction requires continual barrage of Action potentials
- Recruiting additional motor units
- Innervation ratios vary from muscle to muscle
- Muscles with large numbers of small motor units have more control
Activity at Neuromuscular Junction: What happens when an action potential reaches a muscle cell?
- Action potential travels to axon terminal
- Ach binds to receptors, opening ion channels
- Membrane depolarizes, produces large EPSP in postsynaptic membrane
Na+ flows into the muscle fiber,
K+ flows out of muscle fiber - Reaches threshold, Action potential propagates
- Triggers contraction of the muscle fiber
Excitation-Contraction Coupling: What happens in the muscle fiber to cause contraction?
- Sequence of events that converts action potentials in a muscle fiber to a contraction
- Action potential across entire sarcolemma
- Proteins that control Ca++ release channels
- As action potential travels through membrane, opens Ca++ channels, allowing it to flow in the cell
- Rapid influx of Ca++ causes muscle contraction
The Cross Bridge Cycle: What happens when the muscle fiber contracts?
Functional unit of contraction in muscle fiber called sarcomere
Cross bridges formed between myosin head and actin fibers
Power stroke: ADP released, activated myosin head pivots, sliding actin toward center of sarcomere
Cross bridges detach; another ATP binds to myosin head, link weakens and detaches
Reactivated myosin head; ATP to ADP, releasing energy, reactivates myosin head ready for next cycle
Cross bridge cycling ends when Ca++ actively transported back to Sarcoplasmic Reticulum
FCP and Speech:
Components of speech Includes cranial nerves involved in
Respiration:
Phonation:
Resonance:
Articulation:
Prosody:
Flaccid dysarthria (LMN damage):
Apraxia of Speech: production and planning
Neurological damage leading to AOS can occur in:
Respiration: power for speech
Phonation: raw sound for speech
Resonance: tonal qualities of speech
Articulation: speech sounds
Prosody: musical quality of speech
Flaccid dysarthria (LMN damage): Breathy voice, monopitch, hypernasal, short phrases, imprecise consonants
Apraxia of Speech: production and planning
Neurological damage leading to AOS can occur in:
- Broca’s area (BA 44, 45)
- Supplementary motor area (BA 6)
- Insula (insular cortex)
- Basal ganglia
Language:
Generative—
Dynamic—
Universal characteristics—
Ideas expressed—
Conventional—
Arbitrary symbols—
Language: a generative and dynamic code containing universal characteristics whereby ideas about the world are expressed through a conventional system of arbitrary symbols for communication
Generative—meaning that we produce new and different speech constructions all the time; we don’t have rote utterances, they are all slightly different even when expressing the same idea
Dynamic—languages change over time; study of historical linguistics, how language change occurred through history
Universal characteristics—all languages follow specific rules and have the same categories of words (nouns, verbs, adjectives, etc)
Ideas expressed—goal of language is to transmit information or a message from one person to another in an abbreviated way; E.g., communication can be achieved by other means (gesture, pointing, drawing pictures), but language allows us to simplify that process and make it more efficient
Conventional—shared by a speaking community; we can all understand each other because we all speak the same language
Arbitrary symbols—sounds or letters in words do not usually have a direct or specific relationship to the object (e.g., “book” is just the agreed upon string of sounds we use to label that thing made of paper that you read)
The Parts of Language:
Content
Form
Use
Content= semantics, meaning of language
- The meaning of words (e.g., “dog”)
- The meaning of words in combination
- (i.e., semantic relations; e.g., “dog barks”
Form=
- Phonology – Study of phonemes, the smallest units in a language system, and sound structure (e.g., /p/)
- Morphology – Study of morphemes, the smallest units of meaning in a language, and word structure (e.g., /pet/)
- Syntax – Study of phrase/sentence structure; specifically, word order and sentence organization (e.g., /My pet is a dog./)
Use= pragmatics, practical use of language; interactions with others, turn taking, eye contact
- Pragmatics - take turns
- Practical use of language; in what manner the language is used with others
- Example of a pragmatic rule: “In conversation, it is appropriate to take turns.
Classical Wernicke-Lichtheim-Geschwind Model:
Broca’s area =
Wernicke’s area =
Arcuate fasciculus =
Broca’s area = language production, frontal gyrus
BA 44 = pars opercularis
BA 45 = pars triangularis
1. Selects relevant information from competing irrelevant information - NOT specific to language, but processes all kinds of information
2. Specific role in processing complex syntactic structure - Only role is specific to language
3. Some areas specific to language and other areas more general - Used mostly for language processing BUT other parts of this area more general
4. Morphological manipulation - E.g., Adding/interpreting word endings -ed, -ing
Wernicke’s area = language comprehension
Arcuate fasciculus = interaction between comprehension & production (e.g., repetition, reading aloud)
An updated alternative view:
Memory, Unification, and Control Model
White matter tracts involved in language network:
Language is NOT separated into comprehension and production, but is a unification of different types of linguistic processing
Language is not processed by single brain regions
Language is processed by a DYNAMIC NETWORK of brain regions - Role of each brain region is dependent on the interaction with other regions
White matter tracts involved in language network:
Connectivity between language regions much more extended than previously thought
Notice, the arcuate fasciculus is not just one direction!
Auditory Comprehension of Language:
STEPS:
Cochlea to cochlear nuclear complex (CNC) via cranial nerve VIII-8 to thalamus to primary auditory cortex (41,42) to Wernicke’s area (22) to BA 44 of Broca’s area (syntax)
- Primary auditory cortex analyzes all types of sound, speech or otherwise
- Left primary auditory cortex more sensitive to speech characteristics (e.g., timing, transitions between speech sounds)
- Right primary auditory cortex more sensitive to pitch of speech
- Planum temporale on Wernicke’s area, brings information in from surrounding brain areas
- Planum temporale on Wernicke’s area, function not entirely known, but possibly acoustic analysis
- Some syntactic processing, but mostly implicated in storage of verb arguments
- Broca’s possibly related to more complex syntactic processing
Visual Comprehension of Language (Reading):
Steps:
3 cortical areas involved:
Steps:
Eyes to lateral geniculate nucleus (LGN) of thalamus via optic tracts
LGN to visual cortex (17,18,19) via geniculocalcarine tract
Visual areas to ventral and dorsal streams of vision
For reading, 3 other cortical areas involved:
Parietotemporal system
Word analysis: Decoding semantics & phonology
Includes angular gyrus (BA39), supramarginal gyrus (BA40), posterior superior temporal lobe
Occipitotemporal system
Word form recognition: Sight reading, fast access to whole words, assists with mapping letters to corresponding sounds
Left inferior occipital, left inferior-posterior temporal areas, fusiform gyrus (face & word recognition)
Anterior reading system
Word analysis: Decoding syntax and articulation; maybe role in silent reading
Broca’s area, premotor areas
Oral Production of Language:
Steps:
Decision to speak formed in the prefrontal cortex.
Decision sent to Broca’s area (44,45) for language encoding and speech planning.
Speech plans sent to supplementary motor area (SMA) (6), which activates the plans.
SMA (6) sends to motor cortex (4), which sends activated plans to speech muscles
Written Expression of Language:
Steps:
Decision to write formed in the prefrontal cortex.
Decision sent to Broca’s area (44,45) for language encoding.
Writing plans sent to premotor area (6), which forms grapheme motor plans.
Premotor area (6) sends to the motor cortex (4), which sends plans to hand muscles.
Areas 5 and 7 aid visual spatial elements of writing.
Aphasia:
An acquired multimodality language disorder
Fluent aphasia VS Non fluent aphasia
Acquired = caused by stroke, brain injury, etc.
Multimodality = problem in multiple language modalities (listening, speaking, reading, writing)
Language = the symbolic code we use to communicate
Disorder = language system does not function as it should
NOT a disorder of intellect or cognition expect for working memory or a disorder of perception
Fluent aphasia - wernickes
Non fluent aphasia - broca’s
Symptoms of Aphasia:
Expressive language problems:
Agrammatism:
Anomia:
Jargon:
Paraphasias: semantic, phonemic, Verbal, Neologistic
Stereotypic utterances:
Agraphia:
Receptive(reading) language problems:
Auditory comprehension loss:
Alexia:
Peripheral alexia:
Central alexia:
Writing Problems:
Agraphia:
Peripheral agraphia:
Central agraphia:
Expressive language problems:
Agrammatism: Broca bad grammar
Anomia: inability to name or retrieval specific - all types of aphasias
Jargon: wernickes - fluent speech not making sense
Paraphasias: semantic (mixing up like cat for dog - related), phonemic (sound similar - model bottle), Verbal, Neologistic (same as jargon but made up mixed up words)
Stereotypic utterances: only say one word
Agraphia: all types of aphasias - writing problems
Receptive(reading) language problems:
Auditory comprehension loss: all aphasia won’t understand everything 100% mostly broca also werencikes
Alexia: reading problems
Peripheral alexia: reading difficulty due to visuospatial and attentional issues
Central alexia: reading system damaged
Writing Problems:
Agraphia: an acquired disorder of writing
Peripheral agraphia: writing difficulty due to visuospatial and attentional issues
Central agraphia: writing system damaged
What is Cognition?
General Cognition Functions:
Executive Function:
Attention:
What is Cognition?
Perceiving, remembering, understanding, judging, memory, attention, and reasoning
Executive Function: Orientation, Memory, New Learning, Reasoning, Problem Solving, Thought Organization
Cognitive functions that order and manage all other cognitive functions (e.g., attention, memory) for the purpose of setting and attaining goals
The prefrontal cortex is located at areas 9, 10, 11, 46 and 47.
Attention: a person’s ability to focus (i.e., focused attention) on a stimulus in the environment.
Attention: a person’s ability to focus (i.e., focused attention) on a stimulus in the environment.
Attention Types: Sustained
Attention Types: Selective
Attention Types: Alternating
Attention Types: Divided
Attention Types: Sustained
Focus on a stimulus over a period of time
Examples:Reading a book, Listening to a lecture
Attention Types: Selective
Focusing on a stimulus while filtering out competing stimuli
Example: Listening to this lecture while ignoring the texts coming in on your phone and the conversation your neighbors are having
Attention Types: Alternating
Shifting focus from one task to another and then back
Example: In class, focusing on this lecture, then discussing a question with your neighbor, then focusing on the lecture again
Attention Types: Divided
Focus on two stimuli at the same time
Example: Taking notes in class while simultaneously listening to the lecture
Memory:
Sensory memory =
Working memory =
Short-term memory =
Long-term memory =
Memory: the storage of information
Sensory memory = memory related to senses, visual, auditory, olfactory, etc.
Working memory = space for manipulation
Short-term memory = time in seconds
Long-term memory = time in days to years - biographical info
Decelerative: episodic and semantic = dementia in MT and diencephalon
Non Decelerative: Disease in BG is parkinsons and huntingtons
PHASES OF SWALLOWING:
- Oral preparatory phase
- Oral phase
- Pharyngeal phase
- Esophageal phase
PHASES OF SWALLOWING:
1. Oral preparatory phase:
Voluntary stage of the swallow, Food is placed in the mouth and prepared for swallowing, Oral breathing ceases, and nasal breathing takes its place. Mastication (chewing) involves
- Trigeminal nerve (CN V) innervates the muscles for mastication (i.e., chewing)
- Mandibular elevators: masseter, temporalis, and pterygoid
- Mandibular depressors: mylohyoid and anterior belly of digastric muscle
then gland secretion with saliva works along side mastication to break down food using CN IX 9 and CN VII(7)
PHASES OF SWALLOWING:
2. Oral phase:
Voluntary stage of the swallow
Tongue forms ramp and moves bolus from the oral cavity to the pharyngeal cavity
Labial seal and nasal breathing maintained
then
Tounge retraction using trigeminal nerve CN VII controlled by Digastric muscle and Mylohyoid muscle then anterior - posterior bolus movement where Hypoglossal nerve (CN XII 12) controls most of the intrinsic and extrinsic tongue muscles
PHASES OF SWALLOWING:
3. Pharyngeal phase:
Involuntary stage as bolus contacts faucial arches: Soft palate elevates, Vocal cords adduct, Respiration pauses, Larynx elevates, and Cricopharyngeus relaxes. Brainstem involved when Nucleus tractus solitarius (NTS) acts as a swallowing sensory center and receives afferent information from CN V, VII, IX, and X. Then Nucleus ambiguous (NA) is the motor swallowing center and Innervates the swallowing muscles via CN IX 9, X 10, and XII 12. Then triggering of sensory information sent to brainstem & cortex decided by medulla, then laryngeal closure so valves close to protect the airway from the bolus entering it. Then laryngeal elevation - various suprahyoid muscles contract during the pharyngeal stage so normal swallow example. Then pharyngeal constriction is controlled by CN X 10 and XI 11.
PHASES OF SWALLOWING:
4. Esophageal phase:
Involuntary swallowing stage when peristaltic waves move bolus through the esophagus. Esophagus opening by upper esophageal sphincter (UES) is controlled by the cricopharyngeus (CP) muscle which is innervated by the vagus nerve. Then Esophagus constriction collapsed when a bolus is not present and contains 3 parts
Cervical region: made up of striated muscle
Thoracic region: made up of striated and smooth muscle
Abdominal region: made up of smooth muscle
NEUROLOGICAL SWALLOWING DISORDERS:
Silent Aspiration:
Dysphagia:
Causes
Oral Preparatory Stage:
Oral Stage:
Pharyngeal Stage:
Esophageal Stage:
Silent Aspiration: bolus penetrates the airway below the level of the vocal cords.
About one-third of dysphasic patients aspirate without any signs (i.e., no cough).
Dysphagia: Diffculty swallowing
Causes - Neurological Causes:
Stroke, TBI, Spinal cord injury, Degenerative diseases, Brain tumors OR Mechanical Causes: Acute inflammations, Cancer, Cervical spinal disease, NG tubes, Artificial airways
Oral Preparatory Stage:
Difficulty chewing
Food falling out of mouth (poor lip seal)
Oral Stage:
Food remaining in mouth (pocketing)
Difficulty forming bolus
Difficulty moving bolus backwards in mouth (anterior to posterior movement)
Pharyngeal Stage:
Swallow delay
Swallow absence
Pooling of bolus
Esophageal Stage:
Bolus staying in esophagus (dysmotility due to lack of peristaltic waves)
The McGurk Effect
The illusion occurs when the auditory component of one sound is paired with the visual component of another sound, leading to the perception of a third sound.
difference between /da/ and /ta/?
Neural Basis Of Hearing
Two Main Divisions:
Peripheral Auditory System
Central Auditory System - processing is bilateral
Hearing → Acoustic Energy Waves → Neural Impulses → Interpreted By Brain
Peripheral Auditory System:
Outer Ear Stage: Sound located in the environment, Pinna collects sound
Middle Ear Stage: Tympanic membrane vibrates, Energy transmitted through ossicles
Inner Ear Stage: Waves in the cochlear fluids
Central Auditory System:
Auditory Cortex - Thalamus - Brainstem Midbrain - Brainstem Medulla Pons - CN V11 7
Hair cells depolarize similar to neurons.
