Studied by 1 person
Directional Terms
-Anterior/Posterior
-Superior/Inferior
-Rostral/Caudal
-Dorsal/Ventral
Anatomical Planes
-Sagittal -Coronal -Transverse
The Nervous System
Major Divisions: -Central Nervous System (Brain and Spinal cord) -Peripheral Nervous System (Cranial and Spinal nerves)
CNS Protective Coverings
-Skull that surrounds the brain -Vertebral column that protects the spinal cord
Three membranous coverings: meninges -Dura mater -> outermost layer closest to skull -Arachnoid mater -> middle layer -Pia mater -> innermost layer closest to brain
Cerebrospinal fluid (CSF) - between arachnoid and pia mater -Mechanical buffer for protection -Chemical mediator for metabolic functions
Brain
Major divisions: -cerebrum -cerebellum -brainstem
Cerebrum
Cerebral hemispheres
Lobes: -frontal -temporal -parietal -occipital
Cortex -contains the gray matter
Subcortical structures -contains the white matter
Landmarks - Fissures -medial longitude fissure -central sulcus (fissure of Rolando) -lateral sulcus (Sylvian fissure) -superior temporal sulcus
Subcortical Structures
Basal ganglia: -Caudate nucleus -globus pallidus -putamen
-contains dopamine -> lack of dopamine -> movement disorders ie. Parkinson's
Thalamus
Cerebral Connections
Association fibers: -conn. areas within the hemisphere -forms association tracts -> Short (within the lobes) and Long (btw. the lobes) -Arcuate Fasciculus
Arcuate Fasciculus
travels from post. temp lobe to motor association cortex via the superior longitudinal fasciculus
Cerebral Connections - Commissural fibers
-connect areas between hemispheres -corpus callosum - major commissural tract
Cerebrum...
Landmarks (Gyri): -precentral gyrus -postcentral gyrus -angular gyrus -supramarginal gyrus -sup., mid., & inf. temporal gyrus
Cerebrovascular accident (CVA)
Ischemic vs. Hemorrhagic strokes
Ischemic Strokes
-thrombotic—large artery atherosclerosis
-embolic—cardioembolism, lungs
Hemorrhagic Stroke
-subarachnoid—aneurysmal bleeding, Arteriovenous malformation (AVM)
-intracerebral—hypertension, AVM
Ballooning of blood vessel is an aneurysm
-due to weak blood vessel wall
-bursting releases blood, which damages tissues
The brain's blood supply moves up fr. the aorta
-Common carotid branches to form internal and external carotid arteries
-Vertebral arteries join to form
Middle Cerebral Artery
-Supplies entire lateral cortex -Largest branch of internal carotid artery -most likely to cause aphasia
The anterior and middle cerebral arteries supply brain areas critical to speech & language
-Anterior cerebral artery supplies medial frontal & parietal lobes, basal ganglia, corpus callosum
-Middle cerebral artery supplies lateral surfaces of frontal, motor strip, Broca's area, Wernicke's area
Basilar artery
-branches to supply the cerebellum and inferior temporal and occipital lobes
Function of CSF
-cushioning and shock absorption -chemical protection -exchange nutrients and wastes
Broadly, each lobe is supports in a different set of general functions
Frontal: -higher-order cognition -motor planning and motor control
Parietal: -sensory reception, integration
Occipital: -vision
Temporal: -audition
Information moves from primary to association areas
Vision -first occipital lobe, then further processing in parietal and temporal lobes
Motor function -sensory data from parietal lobe goes to motor areas in frontal lobe
Effects of damage differ by hemisphere
Left hemisphere -speech and language -Left hemisphere damage -sequential, rapid input
Right hemisphere -faces and forms -intonation, emotional cues -Right hemisphere damage
The character of the speech disorder differs by location of the damage
-Lower motor neuron damage (cranial nerves)
-Cerebellar damage
Lower motor neuron damage (cranial nerves)
-Flaccid dysarthria -weakness and low muscle tone (hypotonia) -fasciculations (twitching) if cell bodies damaged -reduced or absent reflexes
Cerebellar damage
-Ataxic dysarthria -problems with motor coordination -> coordinating rate, range, and force of movement.
Aphasia can also be considered a disruption to a network of brain areas
Speaking a heard word
1.Sound to primary auditory cortex 2.Wernicke's area analyzes sound to determine word meaning 3.Meaning is transmitted via arcuate fasciculus to frontal lobe. 4.Broca's area forms motor plan to speak word 5.Motor cortex implements the plan by sending signals to muscles
Damage to right hemisphere can also affect language abilities
Impaired ability to interpret humor
Impaired pragmatics—inappropriate responses
Loss of nuances and secondary meanings of words
Difficulty with multi-component thought integration and reasoning
Difficulty with organization
We cover more of RH dysfunction in week 10
Main point: Brain functions are supported by networks of brain areas: Example: Speech motor control
Motor strip (precentral gyrus) initiates voluntary muscle movements (BA 4)
Planning and integration from pre- motor area (BA 6)
Sense of muscle state and position in post-central gyrus (Parietal)
Broca's area involved in motor program for speech (BA 44, 45)
When lesions don't match symptoms
Read the chart and understand medical history thoroughly
Operating Rule for therapists: Treat what you see.
Possible Explanations: -Network interruptions (white matter tracts, subcortical sites of lesion) -Cross brain dominance -Diaschisis -Pre-morbid learning/pre-morbid linguistic and cognitive status (neuroplasticity)
diaschisis
Von Monakow, et al. (1969) initially proposed the concept in 1905
After focal brain injury, neurons in regions of intact brain, distant from, but anatomically and functionally connected to damaged area(s), become functionally impaired because of a loss of excitatory neural transmission from the injured area.
Can cause what appears to be a focal and significant aphasia, despite a neurologically intact peri-Sylvian region
Patterns of recovery
Two Stages: Early - within first several weeks (Acute aphasia) Late - months and years post stroke (Chronic aphasia)
Receptive skills improve more! Receptive skills - necessary for recovery!
-Patients who "evolve" may show better outcome
Spontaneous Recovery
We do nothing and they recover on themselves
1-3 months post onset of aphasia
-Fastest recovery: 1 month post
-Drops precipitously at about 6-7 months post recovery
-Spontaneous recovery effectively over after 1 year post
-Clinical status at 3 months is very similar to clinical status at 12 months
Research: Consider time post in reading studies - should be studying treatment effects in chronic phases, rather than in spontaneous recovery phases
Prognostic factors: neural mechanisms
Initial Severity - very predictive
Not lesion size alone - lesion location more important!
Site of lesion and damage to penumbral areas
Pre-existing lesions or conditions
Neuroplasticity
Involvement of Wernicke's area
Involvement of subcortical white matter along with cortical areas of speech
In Broca's aphasia, extension of lesion anteriorly into areas responsible for executive functions
Prognostic factors: Personal
Age - Advanced age -not really helpful for the recovery process
Gender
Handedness
Psychosocial elements
Pre-morbid education and experiences
Pre-morbid IQ and mental flexibility
Family involvement
Supported Conversation for Adults with Aphasia
-Trademarked approach (Aphasia Institute) to facilitate communication among adults with aphasia and their conversation partners
-Conversational partners are trained in SCA
Study evaluated communication among adults with aphasia and volunteers who did or did not have training in SCA -Volunteers trained in SCA scored higher on measures of "acknowledging competence" and "revealing competence." -Adults with aphasia who were paired with volunteers trained in SCA scored higher in "message exchange skills" and "social skills."
Why Should We Use SCA?
-Interaction (social implications): Acknowledge the competence of the adults with aphasia
-Information: Learn what the adult thinks and feels; provide information to the adult
-Training: Model behaviors for patient, family members, and peers
Components of Supported Conversation
-Acknowledging Competence
Revealing Competence—will require VERBAL and NON-VERBAL techniques -Getting your message IN -Getting their message OUT -VERIFYING
Acknowledging Competence
Implicitly: -Non-patronizing speech patterns (tone, rate, loudness, enunciation) -Choice of topics -Use humor appropriately -Sensitivity to partner's attempts to communicate
Explicitly: -"I know that you know." -As the conversational partner, take ownership of breakdowns in conversations, "I'm sorry I'm confused. Let me try again."
Getting Your Message IN
Verbal techniques: -short, simple sentences
Non-verbal techniques: -Gestures (meaningful and slightly exaggerated) -Writing (use key words) -Other resources (communication book / draw pictures or use pre-printed pictures)
-provide extra time
Get Their Message OUT
-verbal techniques (e.g. ask yes/no questions)
Non-verbal techniques: -gesture (provide models of nodding/shaking head or thumbs up/down) -writing (choices, paper and pen available) -resources (communication book, pain scale, drawing choices, paper and pen available)
Extra time
Verify
Verifying should involve a different modality
Verbal: "Let me check if I am understanding..."
Non-verbal: -gesture -writing (e.g. circle the answer) -resource/drawing
Considerations with Use of SCA
Alter your communication according to your partner: -Provide supports according to level of aphasia -Provide more supports according to patient's needs (think about types of aphasia)
Don't need to fix everything: -Acknowledge the breakdown -Ask permission to come back to it later or to talk to a family member
Other Situations
-Getting the message OUT for people with dysarthria
-Communicating with people with cognitive problems (e.g., difficulty with topic maintenance, thought formation)
