TEST 1 Flashcards
Neurologic causes of communication disorders
- Stroke
- Intracranial tumors
- Hydrocephalus
- Infections/toxins
- Nutritional/metabolic disorders
- Traumatic/Acquired brain injury
- Dementia
Stroke/CVA
-Sudden death of brain cells due to lack of oxygen when blood flow to brain is impaired by blockage or rupture of an artery to brain
Symptoms of a CVA
- Most common symptom is weakness or paralysis of one side of body w. partial or complete loss of voluntary movement or sensation in a leg &/or arm
- speech problems and weakness of facial muscles (facial droop), causing drooling
- Numbness or tingling is very common
- Vertigo/dizziness
- Swallowing problems-dysphagia
- Problems w. consciousness
- Sudden headache
- visual-perceptual deficits
Embolic Stroke/Cerebral Embolism
- Occurs when a fragment of material travels from other parts of body (heart) to neck or brain and blocks a blood vessel
- Fragments may be a blood clot, a piece of atherosclerotic plaque, tissue from a tumor or tissue from a tumor
- Symptoms are rapid in onset
Effects of Stroke-Right Hemisphere
- Left hemiparesis (weakness) or hemiplegia (complete loss of strength)
- Analytical, spatial and perceptual deficits-judging distances, sizes, speed, position or relating parts to whole
- Left-neglect-ignore objects in the left visual field
- Impulsivity
- Anosognosia-lack of awareness of deficits, which leads to poor safety awareness and poor decision making (may try to drive a car)
- Short-term memory deficits
Anosognosia
lack of awareness of deficits, which leads to poor safety awareness and poor decision making (may try to drive a car)
Neurologic Examination (4)
- Cranial nerves
- Motor System
- Consciousness/Cognitive Status
- Radiologic Studies
Ischemic CVA
”deprived of blood”
- blockage of artery causes lack of blood supply to parts of CNS which that artery “feeds”
- 80% of stokes are ischemic
- Can be thrombotic or embolic
Thrombotic stroke/cerebral thrombosis
- an artery to brain is blocked by a clot
- Occur mostly in large arteries-internal carotids, vertebrals and the basilar arteries
- Occlusion for more than a few minutes (3-5) causes death/necrosis of CNS tissue
- ischemic CVA
- blood flows through arteries it changes directions at bends and bifurcations where arteries narrow
- change in direction and size cause turbulence and increased velocity which roughens inner lining of artery and causes a plaque to form-atherosclerotic plaque
- plaque reduces size of space (lumen) w. in artery and causes stenosis
- As lumen size decreases so does vol of blood flowing through it
- clot eventually occludes artery causing a thrombotic CVA
- Symptoms slower in onset
Large Vessel Thrombosis
- Thrombotic stroke occurs most often in large arteries, so large vessel thrombosis is most common and best understood type of thrombotic stroke.
- Most are caused by a combo of long-term atherosclerosis followed by rapid blood clot formation
Small Vessel Disease/Lacunar Infarction
-Small vessel disease, or lacunar infarction, occurs when blood flow is blocked to a very small arterial vessel
TIA
- transient stroke that lasts only a few minutes.
- occurs when blood supply to part of brain is briefly interrupted.
- symptoms are sudden and are similar to those of stroke but do not last as long and disappear w. in an hr, although they may persist for up to 24 hrs.
- Most due to small emboli which occlude artery and break-up or dissolve
- occur when an artery is almost fully occluded causing significant changes in blood pressure and flow
Symptoms of TIA
- numbness or weakness in the face, arm, or leg, especially on one side of body
- confusion or difficulty in talking or understanding speech
- trouble seeing in one or both eyes
- difficulty walking, dizziness, or loss of balance and coordination
Hemorrhagic Stroke-Cerebral Hemorrhage
- blood vessel bursts inside brain
- Damage can occur very rapidly bc of presence of blood itself, or bc fluid increases pressure on brain and harms it by pressing it against skull
- Usually associated w high blood pressure, which “stresses artery walls until they break”
- Another cause is an aneurysm.-”a weak spot in an artery wall, which balloons out bc of pressure of blood circulating inside affected artery”
- larger aneurysm is, more likely it is to burst.
Hemorrhagic Stroke Extracerebral
-effects blood vessels of meninges-3 connective tissue layers of the CNS (the pia mater-closest to the CNS structures, the arachnoid and the dura mater-farthest from the CNS)
Subarachnoid hemorrhage
- blood btwn arachnoid and pia matter
- usually due to aneurysm
Subdural hemorrhage
- blood beneath dura matter
- usually due to head injury
Extradural hemorrhage
- blood btwn dura matter and skull
- usually due to head injury
intracerebral hemorrhage
- Internal bleeding in any part of brain
- bleeding may be isolated to part of one hemi (lobar intracerebral hemorrhage) or it may occur in other brain structures, such as thalamus, basal ganglia, pons, or cerebellum (deep intracerebral hemorrhage).”
- Can be caused by tbi, aneurysm or hypertension (high blood pressure)
Effects of Stroke Left Hemisphere
Right hemiparesis (weakness) or hemiplegia (complete loss of strength)
Aphasia
Slow and cautious-need frequent encouragement, prompting, & feedback
Attention deficits
Immediate, short term &/or long term memory deficits
Difficulty w generalization
Effects of Stroke Cerebellar
Poor coordination
Balance problems
Dizziness/Vertigo-can cause nausea and vomiting
Abnormal reflexes-head tick movements, torso jerks
Effects of Stroke Brainstem
Paralysis or paresis of one or both sides of body Problems w regulating breathing Problems w heartbeat and blood pressure Vertigo Disrupts eye movements Pharyngeal phase dysphagia Short-term memory deficits
Motor Assessment
- Muscle tone-tension in muscle when voluntarily relaxed
- Range of motion
- Hypertonia-resistence to passive movement
- Spacticity-muscles are tense and hard resist stretching
- Rigidity-relaxed muscles resist movement
- Hypotonia/flaccidity-”floppy” muscles
- Muscle strength
- Monoplegia-paralysis of one limb
- Hemeplegia-paralysis of both limbs on same side of body
- Quadriplegia-paralysis of all four limbs
- Reflexes- gag, swallow, corneal
- Plantar/babinski reflex-toes bend down (normal)
- Palmar reflex-involuntary grasping of objects
- Dyskinesia-frequent involuntary movements
- Tremor-cyclic, small amplitude movements
- Resting-when muscles are relaxed
- Postural-during certain postures
- Intention-only during volitional movements
- Athetosis-slow, writhing movements
- Dystonia-involuntary contracions lasting long durations
- Fasciculations-fine, rapid, twitching movements
- Tics-repetitive movements (blinking, cough)
- Ataxia-difficulty initiating and terminating muscle movements
- Gait-walking/running
White Matter
Communicating fibers
Afferent and efferent tracts
Upper motor neuron lesions lower motor neuron lesions
Differential diagnosis
Gray Matter
Neuron bodies
Disorder causing demyelination of axon fibers:
MS is result of damage to myelin; affecting messages transfers btwn brain and other parts of body
Fibers (myelinated)
Projection fibers
Association fibers
Comissural fibers
Projection Fibers
Make up tracts (=pathways) connecting cortex w distant structures: brainstem and spinal cord (to and from)
Association Fibers
Communication btwn regions of same hemisphere
One example : arcuate fasciculus
Communication btwn frontal lobe and temporal, and parietal lobes
Damage: Conduction Aphasia - comprehension/expression are intact, but - inability to repeat info presented auditorily
Comissural Fibers
Communication btwn two hemispheres
Corpus Callosum – major group communication fibers
1940 – surgery as epilepsy treatment: cutting corpus callosum. Seizures stopped, but each hemisphere started to operate independently.
Ascending tracts
afferent
Descending Tracts
efferent
Major Descending Tracts
Originate in cortex, travel down brainstem
Pyramidal tracts (the corticospinal and corticobulbar tracts)
Tectospinal
Rubrospinal
Vestibulospinal all extra
Pontine reticulospinal
Medullary reticulospinal tracts
Pyramidal Tracts
carry impulses that convey info about voluntary fine motor movements. Fine motor movement of fingers when typing
Extrapyramidal Tracts
transmit impulses that control more of postural support needed to perform fine motor movements.
Keeping posture to type.
Indirect activation system basically start from brainstem to spinal nerves.
Tracts for Speech
Rubrospinal and Pontine and Medullary reticulospinal
Tectospinal tract
eyes
vestibulospinal tract
hearing and balance
Reticulospinal tract
reticular formation down to spinal nerves.
Tracts as a whole is important for upright posture and body’s ability to attend to external environment
Corticospinal Tract
Responsible for
1.activation of skeletal muscles for voluntary movements
2. Inhibition of reflexes
Composed of axons descending from cortex and terminate in brainstem and synapse w cranial nerves in medulla.
Corticobulbar tract
The corticobulbar regulation of some CNs is bilateral:
Trigeminal, facial (part), vagus, and glossopharyngeal nerves
Unilateral or bilateral innervation and what structures or regions or functions do those cranial nerves help assist.
LMN sometimes called
final common pathway, cranial nerves, or spinal nerves
UMN Lesions
-Corticospinal tract
-Immediately after damage: Muscle weakness, loss of fine motor skills, reduced muscle tone, but later muscle tone returns + muscles become spastic
-Hyperactive reflexes
-Positive Babinski reflex
-Damage before decussation in medulla → symptoms contralateral to area of damage
No muscle degeneration
Axons
- Contain terminal buttons/synaptic buttons
- Covered in thin layer of white, fatty substance myelin sheath
How do neurons work and transmit information?
- axons send electrical signals from the neuron’s cell body to the synaptic buttons. Electrical signal causes buttons to release a chemical (neurotransmitter) which is then received at dendrite of next neuron.
- chemical transfer of neurotransmitter that is picked up by the dendrite and sent to the cell body which tells cell body what electrical signal to send to next neuron.
Dendrites
-short, hair-like fibers that extend from cell body to receive information from axons of other cells
Neurons
- Neurons receive info through dendrites and transmit info through axons
- Nerve cells have 2 parts: soma or cell body and nerve fibers
Synapse
-point at which axon of one neuron meets dendrite of another neuron
Synaptic Cleft
- tiny space btwn an axon and a dendrite
- where synaptic buttons release neurotransmitters
Nerve fiber tracts
- bundles of axons in nervous system
- form white matter of CNS
Neurotransmitter
- chemicals contained within terminal buttons which aid in contact between two nerves
- may excite or inhibit next neuron
Projection Fibers
- carry info from brain to brain stem and spinal cord or from peripheral sensory nerves
- efferent and afferent
Efferent projection fibers
motor nerves-carry signals from the motor and pre-motor cortex through the brain to the muscles and glands
Afferent projection fibers
sensory nerves-carry sensory info from sensory receptor cells via peripheral sensory nerves throughout PNS through spinal cord to brain
Somatic nervous system
Sensory perception & volitional motor activity
Major components-cranial nerves & spinal nerves
Autonomic nervous system
Controls involuntary functions such as breathing and heartbeat
Divided into sympathetic (panics) and parasympathetic (calms) branches
Cranial vault
space inside skull
Ventricles
- 2 lateral ventricles which are both connected to third ventricle which is connected to fourth ventricle
- ventricles contain choroid plexus which are soft masses of tissue which produce cerebrospinal fluid
Frontal Lobe
-Posterior boundary is central fissure and lower boundary is lateral fissure
-Contains motor speech area or “Broca’s Area”
Planning
Problem solving
Inhibition
Short-term or working memory
Motor behavior
Regulates social behavior
Parietal Lobe
-Behind central fissure and above lateral fissure
-Supramarginal gyrus-problems w writing (agraphia)
-Angular gyrus-naming and reading problems
-“Wernicke’s Area” is only partially in parietal lobe
Attention
Combines information from different senses
Processes skin pressure
Processes touch
Processes skin temperature
Processes pain
Temporal Lobe
-Bottom third of each hemisphere-lateral fissure forms top boundary
-Sensory speech area/Wernicke’s Area (left hemisphere only)-comprehension of written and spoken language
Process verbal meaning
Speech production
Process emotion in speech
Process auditory pitch
Memory for faces
Object recognition
Long-term memory
Some visual processing
Emotion and personality
Comprehending speech/Auditory reception-Primary auditory cortex & Auditory Association Area
Primary Motor Cortex
In both hemispheres but larger in left hemisphere
Known as Herschel’s gyri
Primary function is hearing
Occipital Lobe
Located behind parietal lobe Smallest lobe Primary Visual Cortex Processing visual stimuli Processing color Processing motion Processing form Imagery
Motor Cortex
- Control of skilled movements
- Located just in front of central fissure
- A homunculus or map is used to depict cortical area responsible for muscle groups
- larger representation the more diverse, intricate and precise movements required
Primary Sensory Functions of Left Hemisphere
Sensation of right body
Perception of right visual field
Appreciation of sound from right ear
Look up picture of lobes of brain
don’t forget lateral sulcus
Primary Sensory Functions of Right Hemisphere
Sensation of left body
Perception of left visual field
Appreciation of sound from left ear
Left Hemisphere Language Skills
-comprehension and expression of oral and written lang including storage and recall of symbols and nominals
-storage of common nouns and action verbs rules of grammar and structure of language
verbal word recognition
Right Hemisphere Cognitive Functions
Spatial orientation Spatial relations Sequencing of symbols, objects, and events Timing and time perception Music appreciation Recognition of objects and faces Geometric communication Non-verbal communication Fundamental movement of left body Left voluntary gaze Motor persistence Order Planning Volition Diligence Executive control-problem solving, reasoning Abiding by rules and regulations
Left Hemisphere Emotional Functions
Denial, oppositional behavior, non-compliance, and hostile anger (mania) Obsessions and compulsions "Learned" pessimism and negativity Pedantic/wrote, rigid responses Rationalization
Left Frontal Lobes Functions
Fundamental movement of right body
Right voluntary gaze
Clarity of verbal thought (freedom from auditory-verbal hallucinations and delusions)
Right Hemisphere Emotional Functions
Prosody Primary emotionality Empathy and comprehension of emotionality Affective behavior (depression) Wit and humor
Primary Visual Imagery of Right Hemisphere
Picture-to-picture storage and representation
Symbolization (symbolic representation)
Picture-to-word storage and representation
Diencephalon
Located deep in cerebrum at top of brain stem btwn cerebral hemispheres
Contains thalamus and basal ganglia
thalamus
integrates sensory experiences and relays them to cortical areas
-plays an important role in consciousness, alertness and attention
basal ganglia
r-regulation and adjustment of major muscle groups in trunk and limbs
- receives input from frontal lobe
- damage causes problems w movement and sensation and results in appearance of involuntary movements called dyskinesia
Brainstem
communicative and structural link between the brain and spinal cord
- midbrain
- pons
- medulla oblongata
olfactory
sensory
ocular
sensory
oculomotor
motor
trochlear
motor
trigeminal
both
abducens
motor
facial
both
vestibulocochlear
sensory
glossopharyngeal
both
vagus
both
accessory
motor
hypoglossal
motor
cerebellum
- Looks like a miniature brain w 2 hemispheres and an outer layer of grey matter called cerebellar cortex
- Coordinates and modulates movements
- Regulates rate, range, direction, and force of movement
- Coordinates smooth and rhythmic movements-including speech
- Does not initiate movement!
- damage causes clumsy movement (ataxia)
- Located at base of brain behind pons and medulla
Blood Supply 5 steps
- Aorta-oxygenated
- Subclavian Arteries: Branch off into common carotid arteries and into vertebral arteries
- Vertebral arteries join together at base of pons and form basilar artery
- Common Carotid Arteries
- Internal and External Carotid Arteries
- External carotids lead off to face
- Internal carotids proceed up toward brain on each side of neck (near skin surface- what we feel to get a pulse)
- Circle of Willis located at base of brain where 2 carotids and basilar artery meet
