The Cerebellum Flashcards
(97 cards)
1
Q
The Cerebrum
A
Diencephalpn
Cerebral Hemispheres
2
Q
Diencephalon
A
Thalamus
Hypothalamus
Epithalamus
Subthalamus
3
Q
Thalamic Injury
A
- May interrupt ascending pathways, severely compromising or eliminating contralateral sensation
- Usually proprioception is most effected.
- A thalamic pain syndrome may ensue, producing severe contralateral pain that may occur with or without provoking external stimuli.
( have to determine if it is Thalamic or Musculoskeletal origin) Pain is not a typical Post Stroke symptom unless it is a thalamic stroke origin. Delayed Musculoskeletal pain can occur post stroke and be relieved with treatment!)
4
Q
Cerebrum
A
Cerebral Hemispheres + Diencephalon
Cerebral Hemispheres
- —-Cortical Areas
- —-Subcortical Areas
5
Q
Subcortical Structures: Basal Ganglia
A
Caudate Putamen Globus Pallidus--- -----Internus and externus Subthalamic Nucleus Substantia Nigra
Globus pallidus + Putamen = Lentiform Nucleus
Caudate + Putamen = Striatum
6
Q
Basal Ganglia Functions
A
- Vital for normal motor function
- Executive function
- –Goal Directed Behavior - Sustained attention
- Ability to change behavior as task requirements change
- Motivation
7
Q
Subcortical Structures
A
Subcortical White Matter ---Projection, commissural and association fibers -----Corona Radiata -----Internal Capsule Basal Ganglia (Deep Cerebral Nuclei)
8
Q
Subcortical Structures: Subcortical White Matter
A
- Projection, commissural, and association fibers
- Corona Radiata
- Internal Capsule
9
Q
Types of White Matter FIbers
A
Projection
Commissural
Association
10
Q
Projection Fibers
A
extend into and out of the cerebrum
Thalamocortical
Corticospinal
11
Q
Commissural Fibers
A
connect homologous areas
Corpus callosum
Anterior white commissure
12
Q
Association Fibers
A
connect cortical areas within one hemisphere
Short association fibers
Superior longitudinal fasciculus
Inferior longitudinal fasciculus
13
Q
Internal capsule Review
A
Anterior Limb
lateral to head of caudate
frontopontine fibers
fibers interconnecting thalamic and cortical limbic areas
Genu
most medial portion and “knee bend” of IC
cortical fibers to cranial nerve motor nuclei and reticular formation
Posterior Limb
between thalamus and lenticular nucleus
corticopontine fibers
corticospinal fibers
thalamocortical projections
somatosensory, auditory, visual, and motor information to cerebral cortex
14
Q
Subcortical White Matter Lesions
A
+Occlusion or hemorrhage of arteries supplying the internal capsule is common.
+Because the internal capsule is composed of many projection axons, even a small lesion can have severe consequences.
—-Catastrophic hemiplegia with somatosensory loss, auditory and/or visual impairments
15
15
Q
Cerebral Cortex
A
Vast collection of cell bodies, axons, and dendrites
6 cortical layers
Primary cells:
Pyramidal – output cells; apical dendrite to cortex surface, several basal dendrites, and one axon
Fusiform – output cells, primarily to the thalamus
Stellate – interneurons
16
Q
Looking at the Axon
A
Axon Hillux free of organelles
17
Q
Basal Dendrites stay primarily
A
with in the paramaters of the cortex
18
Q
Layers of the Cerebral Cortex
A
I Molecular layer; ainly axons and dendrites; contains few cells
II External granular layer; many small pyramidal and stellate cells
III External Pyramidal layer; pyramidal cells
IV Internal granular layer; mainly stellate cells
V Internal pyramidal layer; predominately pyramidal cells, with stellate and other interneurons
VI Multiform layer, primarily fusiform cells
19
Q
Primary Sensory Cortex
A
simple sensory discrimination (intensity and quality)
20
Q
Secondary Sensory Cortex
A
Recognition or sensations
21
Q
Association Cortex
A
Goals selection
Interpretation of sensation
Emotions, memory processing
22
Q
Motor planning areas
A
Movement, composition, sequencing
23
Q
Primary motor cortex
A
Cortical motor output
24
Q
Cerebral Cortex
A
Mapping=Brodmann’s Areas
Issues of Cerebral Dominace
25
Primary Sensory Areas
Somatosensory 3, 1, 2,
significant number of paramydal cells that can originate here
Discriminates shape, texture, or size of objects
26
Injury to 3,1,2
Depends on which part of somatosensory hommunculus cortex affected (look at picture)
Lateral Hemisphere _Middle cerebral
Medial Hemisphere-lateral cerebral artery
27
A stroke that affects the entire side of the body
Has to be internal
| Corona Radiata
28
Auditory 41
Conscious discrimination of loudness and pitch of sounds
29
Visual 17
Distinguishes intensity of light, shape, size and location of objects
30
Vestibular 40
Discriminates among head positions and head movements
31
Sensory Association Areas
Somatosensory= 5,7
| -----sterognosis and memory of the tactile and spatial environment
32
Sensory Association Areas
Auditory=22,42
| Classification of sounds
33
Sensory Association Areas
Visual = 18,19,20,21
| Analysis of motion, color, control of visual fixations
34
Secondary Sensory Areas
| Agnosia
The inability to recognize objects when using a specific sense, even thought discriminative ability with that sense is intact.
35
Forms of Agnosia
astereognosis
visual agnosia
auditory agnosia
36
Astereognosis
The inability to identify objects by touch and manipulation, despite intact discriminative somatosensation.
Person with astereognosis would be able to describe an object being palpated but not recognize the object by touching and manipulating it.
37
Auditory Agnosia
Destruction of the secondary auditory cortex spares the ability to perceive sound but deprives the person of recognition of sounds.
1. Lesion is left association auditory cortex.
- --Person is unable to understand speech (speech sounds like a foreign language)
2. Lesion is right association auditory cortex
- ----Person unable to interpret environmental sounds (no meaning attached to sound)
38
Visual Agnosia
1. The inability to visually recognize objects, despite having intact vision
2. Person with visual agnosia can describe the shape and size of objects using vision but cannot identify the objects visually.
39
Primary Motor and Motor Planning
Primary Motor=4
Supplementary motor=superomedial 6---what movement needs to occur!
Premotor=lateral 6
Broca's Area= 44, part of 45--specific to speech for the motor planning of speech
40
Broca's Motor Speech
Typically on the Left Hemisphere
41
Non-verbal communications
Area analogous to Broca's in opposite hemisphere
| Planning non-verbal communication (usually right hemisphere)
42
Primary Motor Cortex 4
Voluntary Controlled movements
43
Premotor Area lateral 6
control of trunk and girdle muscles
| anticipatory postural adjustments
44
Supplementary Motor Area /superomedial 6
Initiation of movement, orientation planning, bimanual and sequential movements
45
Broca's Area (44 part of 45)
Motor programming of speech (dominant hemisphere; usually left hemisphere)
46
Primary Motor Cortex Lesions
1. Dysarthria
---Speech disorder resulting from spasticity or paresis of the muscles used for speaking
---Spastic (harder to treat)(hypertonia)
-----Is caused by damage to the upper motor neurons.
-----Is characterized by harsh sounding, awkward speech. (pharyngeal and laryngeal muscles) Can not get them to relax! Can not touch muscles!
---Flaccid (hypotonia)
-----Is caused by damage to the lower motor neurons. (hypoglossal nerve itself)
-----Is characterized by paresis of speech muscles.
A LMN lesion that leaves the person not moving or using the muscles can lead to eventual hypertonia.
47
Motor Planning Area Lesion
Apraxia
---The knowledge of how to perform skilled movements is lost.
---The person is unable to perform a movement or sequence of movements, despite intact sensation, normal muscle strength and coordination, and an understanding of the task.
---Example: brusing one's teeth with a dry toothbrush then putting toothpaste on the brush
(can tell you how to do it, can tell you the steps, but can not perform them in order!)
PT seen more frequently...ask them to start to move and they freeze up and can not physically move! Try to Congnitively try to initiate the steps one at a time/ or get them started and let them try to finish. Some can't start, Some start and can not go in the correct order--Try to get them to automatically do it without thinking about the individual parts!
48
Motor Planning Area lesions
1. Constructional Apraxia: subtype of motor apraxia
- --Deficit imparis the ability to draw and to arrange objects correctly in space. (building blocks) will need occupational therapy for completion of ADL's
2. Motor preseveration: uncontrollable repetition of a movement
3. Broca's aphasia: difficulty expressing oneself using language or symbols
- --Occurs with adamage to Broca's area (44, part of 45)
49
Other Association Areas
1. Dorsolateral Prefrontal (lateral 8 and 9, 46)
--Goal oriented behavior; self awareness
2. Parietotemporal (parts of 7/19/21/22/37/39/40)
sensory integration, problem solving, understanding language and spatial relationships
3. Ventral and Medial Dorsal Prefrontal (medial 8 and 9, 10, 11, 44, 45, 47)
---Emotion, motivation, personality
50
Dorsolateral Prefrontal
| Lateral 8 and 9; 46
Goal Oriented behavior, self awareness---Injury here will cause people to be socially inappropriate
51
Paroetotemporal Association
| 39.40.parts of 7.19.21.22.37
Sensory integration, problem solving, understanding language and spacial relationships
52
Ventral 11/44/45/47 and Medial Dorsal (8-9-10) Prefrontal Association
Emotion, motivation, personality
53
Dorsolateral Prefrontal Assiciation Cortex Lesions
1. Have little effect on intelligence as measured by conventional intelligence tests (offer options to allow them to have a sese of control)
2. People with prefrontal lesions function poorly in daily life because they lack goal orientation and behavioral flexibility
54
Ventral and Medial Dorsal Prefrontal Association Cortex Lesions
1. Damage to these areas interferes with the emotional events.
2. People with these lesions have intact intellectual abilities but use poor judgement, are impulsive and have difficulty conforming to social conventions.
55
Sensory Information Impacts Social Behavior through
1. Amygdala---endocrine and autonomic areas---Social Behavior
2. Inferior Frontal Lobe (orbitofrontal cortex)---endocrine and autonomic areas and motor areas---Sensory Behavior
3. Anterior Cingulate Gyrun---Motor Areas---sensory behavior
56
Emotional Lability
The abnormal, uncontrolled expression of emotions.
Includes
---Abrupt mood shifts, usually to anger, depression or anxiety
---involuntary, inappropriate emotional expression in the absence of subjective emotion (pathologic laughter or crying)
---Emotion, triggered by nonspecific stimuli unrelated to the emotion expression
(sometimes you have to figure it out others you have to let them rest and remove stimuli before being able to move on.!)
57
Memory (3 types)
Working Memory
---Goal-relevant information for a short time
Declarative
---Facts, events, concepts, and locations
Procedural
---Skilled movements and habits
58
Declarative Memory
```
Conscious, explicit, cognitive
Requires attention
3stages
--immediate/encoding
--sort term--consolidation
--Long Term--retrieval
Dorsolateral prefrontal cortex and media; temporal lobe
---hippocampus and amygdala
(Alhiziemers Disfunction)
```
59
Procedural Memory
```
Nonconscious or implicit
Motor Learning
2 stages
--cognitive
--associative
--automatic/autonomous
Frontal cortex, thalamus, basal ganglia and cerebellum
```
60
Working Memory
Central to cognition
| Prefrontal and parietotemporal association cortex
61
Declarative memory processing
Medial Temporal Lobe
Medial Temporal Cortex
Hippocampus
62
Declarative Memory Processing
Amygdala
63
Preceptual Integraton
Parietotemporal association cortex
64
Organization and categorization of information
Dorsolateral prefrontal cortex
65
Alzheimers
profound loss of neurons in the medial temporal lobe first!
| In advanced it spreads and effects their motor system as well.
66
Declarative Memory Failure: Amnesia
The loss of declarative memory.
Retrograde amnesia
---the loss of memories for events that occurred before the trauma or disease that caused the condition.
People with amnesia retain the ability to form new preferences, despite lacking cognitive awareness of the preferences.
(introduce yourself to them time and time again for their comfort)
67
Definition of Motor Learning (Procedural Memory)
A set of processes associated with practice or experience leading to relatively permanent changes in the capability to perform a motor task.
68
Many factors Involved in Enhancement or Inhibition of Motor Learning
1. Structure of Practice (Blocked vs. Random)
2. Type of Practice (proper form/one thing at a time or all together)
3. Type of Feedback (a lot needed in associative stage but do they need intrinsic feedback from themselves or extrinsic feedback from you) Ask them about the performance before you grade the performance!
4. Amount of Feedback (back off as soon as possible to allow them to use intrinsic feedback)
69
But where is motor memory stored and how is it stored?
Classic Clinical Experimental Case: Individual with BI (brain injury) and amnesia
Must consider separate memory
70
Clinical Implications
1. Declarative memory can be damaged and still have the capacity for motor learning (Alzheimer's Disease)
2. Working and declarative memory support procedural memory
3. Patients with cerebellar or basal nuclei dysfunction will have difficulty forming new motor memories and or with generalizability of new motor task.
71
Cerebral Dominance
1. Although the cerebral hemispheres appear identical both grossly and microscopically, there are certain functions which are not represented equally at cortical levels.
2. In certain higher functions, considered to be cortical in nature, one hemisphere appears to be the leading one and is referred to as the "Dominant Hemisphere"
72
Blocked vs Randomized Treatment
Aerobic/stretching do not follow this!
It matters in terms of motor learning what you need them to learn and remember!
Sit to stand--Stair climbing--Walking
Beginning---Blocked Treatment--no idea of where to begin
As they learn--associative stage--start to randomize things. Sit to stand, Walking, stair climbing! Combing sit...walk...stairs circuit without too much repetition of any one task. Their performance with you may not be great but their ability to learn and perform in life will be better.
In clinic Convenience will tell you to block everything, but it is not very ideal for enhancing motor learning for the patient!
Blocked may help people feeling discouraged and need a psychological boost to get better and move forward! Not long term but boost of morale. Also block for insurance to see that there are improvements overall!
73
Functional areas that are often controlled by the dominant Hemisphere
1. Handedness
2. Perception of Language
3. Speech
4. Spatial Judgement
74
Communication
~95% of people have dominant (L) hemisphere
Language is controlled by the dominant hemisphere
(L) = Language
75
Language
The use of complex abstract symbols to represent one’s perception of the world to another
Verbal = oral vs written
Gestures = sign language
Braille = tactile
76
Communication/Conversations
Primary Auditory (41)
Auditory Association (22, 42)
Wernicke’s Area for language comprehension (39, 40)
Association Fibers between Wernicke’s and Broca’s
Broca’s Area for motor planning (44, part of 45)
Motor Execution (4)
77
Language Disorders
Aphasia-affects spoken lauguage
Alexia-affects comprehension of written language
Agraphia-affects the ability to write
78
Common forms of Aphasia
1. Broca's (expressive)--difficulty expressing or using language(motor planning--motor apraxia--inability to put things together to speak)
2. Wernicke's (Receptive)--language comprehension is impared (inability to recall words) can not understand language
3. Conduction--occurs with damage to the neurons that connect (reception ok but can not put words together to respond.) Wernicke's and Brocca's areas.
4. Global--is an inability to use language in any form. (very difficult to differentiate between an aphasia)
79
Disorders of Nonverbal Communication
Damage to the right cortex in the area corresponding to Broca’s area may cause the person to speak in a monotone, to be unable to effectively communicate nonverbally, and to lack emotional facial expressions and gestures.
Consequences are sometimes referred to as flat affect.q
80
Perception
1. The interpretation of sensation into meaningful forms.
2. Involves memory, motivation, expectations, selection of sendory information, active search for pertinent sensory information
3. Thalamus and many cerebral cortical areas involved
81
Comprehension of Spatial Relationships
1. non-dominant hemisphere area 3
2. Spatial relationship "schemas"
- the body
- the body in relation to surroundings
- the external world
82
Body Schema
1. Also known as body image
| 2. Mental representation of how the body is anatomically arranged
83
Neglect
The tendency to behave as if one side of the body and or one side of space does not exist.
2. People with neglect fail to report or respond to stimuli present on the contralateral side....Typically left hemipalegia. Right brain injury affects contralateral body.
3. Usually affects the left side/right hemisphere lesion
84
Two Forms of Neglect
Personal
Failure to direct attention, affecting the awareness of one’s own body parts
Unilateral lack of awareness of sensory stimuli, personal hygiene and grooming, movement of the limbs
Spatial
Unilateral lack of understanding of spatial relationships, resulting in a deranged internal representation of space
85
Lateropulsion (Pusher Syndrome)
1. Is the powerful pushing away from the less paretic side in sitting, as well as during transfers, standing, and walking.
2. Patient extends the non-paretic arm and leg and pushes, creating a high risk for falls.
3. Patients with this behavior are extremely resistant to attempts to adjust their posture passively to a symmetrical position.
86
Visual Information Processing
2 tracts
1. DORSAL (Action)
2. Ventral (Perceptual)
87
Dorsal-Action Stream
1. From visual cortex to frontal lobe--through posterior parietal cortex
2. Use of vision to direct/adjust your actions
3. Example: When a person reaches for a cup, the visual information in the dorsal stream is used to orient the head and position the fingers appropriately during the reach.
88
Ventral-Perceptual Stream
From visual cortex to temporal lobe
2. Identification of identify objects and environment
3. Example --the stream is going to process information and identify objects-including the cup which you wish to reach for.
89
Consciousness
1. Generalized arousal level
2. Attention
3. Selection of object of attention, based on goals (focus)
4. Motivation and initiation for motor activity and cognition.
90
Depression
1. A syndrome of hopelessness and a sense of worthlessness with abherrant thoughts and behavior
2. Linked to neurotransmitter and neural activity abnormalities rather than to structural abnormalities
3. People with depression have reduced levels of serotonin metabolites in their cerebrospinal fluid.
91
Consciousness is Neurotransmitter Driven
1. Produced by brainstem/diencephalon neurons
2. Delivered to cerebrum viareticular activating system.
a. Serotonin
b. Norepinephrine
c. Acrtylcholine
d. Dopamine
92
Drugs for depression
MAOI--
Tricyclic Antidepressants--increase the activation of serotonin receptors
SFRI-reuptake inhibitors. Decrease the uptake of serotonin to leave it in the system longer
93
Neurotransmitter Function:
```
Serotonin = Generalized arousal level
Norepinephrine = Attention / Direction of consciousness
Acetylcholine = Selection of object of attention, based upon goals
Dopamine = Motivation, motor activity and cognition
```
94
Consciousness
1. Requires neorutransmitters (serotonin and norepinephrine)
AND
2. Activity in the thalamus and cerebral cortex
3. THus, lesions of the brainstem, thalamus, and or cerebral vortex may result in altered consciousness
95
Loss of Consciousness
1. At any age, a blow to the head may cause a temporary loss of consciousness (LOC).
a. From the movement of the cerebral hemispheres relative to the brainstem, causing torque of the brainstem, and from the abrupt increase in intracranial pressure.
2. Consciousness may also be impaired by large, space-occupying lesions of the cerebrum, located in the diencephalon or exerting pressure on the brainstem.
96
Testing Cerebral Function
| page 450 chart
1. Consciousness Level (1. alert/lethargic--2.obtunded-briefly alert but can not respond coherently 3.stupor--only alert during strong stimulation
4. coma---no to limited response to stimulation)
2. Language and Speech--shoot for 3rd grade level a. comprehension b. reading c. writing d. naming
3. Orientation
4. Declarative Memory (long list--where are you, why are you here)
5. Interpretation of Proverbs (abstract thinking)
6. Calculation(100-7...multiplication)
7. Stereognosis
8. Visual Identification (show common object)
9.Motor planning.
use something the right way...button your shirt.
97
Testing Cerebral Function
1. Motor Planning
2. Comprehension of Spatial Relationships
3. Concept of Relationship of Body Party
4. Orientation to Vertical Position
5. Ability to Attend Bilateral Simultaneous Stimulation
