Some details on Ichi liter no namida
I know I haven't been posting notes for so long...
FUNCTIONS OF CEREBELLUM
1. REGULATION OF EQUILIBRIUM
2. REGULATION OF POSTURE
3. REGULATION/ COORDINATION OF VOLUNTARY MOVEMENT
4. FUNCTION IN MOTOR LEARNING
5. FUNCTION IN RAPID & BALLISTIC MOVEMENT
1. Regulation of Equilibrium
2. Regulation of Posture
* Principal region concerned with postural adjustment is vermis
* Receives impulses from proprioceptors
* Adjust body posture via vestibulospinal and reticulospinal tracts
* Control tone of axial and proximal limb muscles
3. Regulation/ Coordination of Voluntary Movement
Coordination - Ability to proceed from one movement to another smoothly, precisely and in proper succession
Coordination is carried out by a number of mechanisms including:
a) Comparator and Error Corrector Mechanism
b) Predictive and Damping Mechanism
c) Planning Sequence and Timing Movement
a) Comparator and Error Corrector Mechanism
* When motor areas of cerebral cortex send motor commands to muscle, spinocerebellum receive an efference copy of intended motor activity via coticopontocerebellar pathway.
* In addition, ventral spinocerebellar pathway send to spinocerebellum another efference copy about signals that reached anterior horn cells of spinal cord.
* As movement proceed, dorsal spinocerebellar pathway send to spinocerebellum information about actual performance of muscle
* Intermediate zone of spinocerebellum compares the intended motor activity to actual performance of movement
* If there is any error in performance, spinocerebellum send corrective impulses to motor cortex which send impulses reaching muscle via descending motor tracts
b) Predictive and Damping Mechanism
* Cerebellum receives information regarding the velocity of intended movement from efference copy
* Sensory feedback signals from muscles and joints provide cerebellum with relative distance
* From these parameters, cerebellum determines the precise time to damp (Stop) the movement, then sends the decision to motor cortex to stop the ongoing movement exactly at intended position
c) Planning Sequence and Timing of Movement
i) Planning Sequence of Movement
- Cerebrocelebellum uses the information from cerebral cortex and basal ganglia for planning of sequence of contraction of different muscle involved in voluntary motor act to achieve goal of movement
- The plan is projected to motor areas of cerebral cortex
ii) Planning Timing of Movement
- Cerebrocerebellum provides perfect timing of voluntary movements determining the onset and termination of each muscle contraction for muscle involved performance of successive movement
- This allows for smooth progression of movement
4. Function in Motor Learning
* When a person first performs a complex motor action, the motor commands are uncoordinated
* After many trials cerebellum begins to coordinate movement so it becomes gradually more precise
* Specific motor program of movement is stored
5. Function in Rapid and Ballistic Movement
Ballistic movements
* Movements that are done very rapidly that it’s almost impossible to depend for their control on sensory feedback information from periphery because the movement would be over before such information reaches cerebellum and cerebral cortex
* Those movement are required for rapid writing, running and professional skills
* These movements are preplanned using stored programs that have been established by motor experiences
CLINICAL DISORDER OF CEREBELLUM
1. Folliculonodular Lobe Lesion
2. Vermal Disorders
3. Hemispherical Disorders
1. Folliculonodular Lobe Lesion
* Lesion leads to disturbance of equilibrium
* Manifested by:
- Swaying during standing with tendency to fall down
- Unsteady gait → Wide base to provide better support
2. Vermal Disorders
* Disturbs postural adjustment
* Patient is unable to maintain the upright standing posture
* Fail to adjust tone and contractility of antigravity muscles
3. Hemispherical Disorders
* Causes:
- Hemorrhage and thrombosis
- Tumours
* Usually destroys the intermediate and lateral zones of cerebellum
* Manifested as neocerebellar syndrome which is characterized by:
a) Hypotonia
b) Athenia
c) Ataxia
a) Hypotonia
- Due to decrease facilitation of gamma motor neuron
- Associated with hyporeflexia
- Knee jerk is characteristically pendular
b) Athenia
- Weakness of muscle
- Due to interruption of activating effect of cerebellum on motor cortex
c) Ataxia (Motor Ataxia)
Note: Go watch Ichi Litre no Namida for example of characteristic of ataxia
Definition: Uncoordination of voluntary movements
Characterized by: 4D KouTa Run iN Unsteady gait - D&R
1. Dysmetria
2. Decomposition of movement
3. Dysdiadochokinesia
4. Dysarthria
5. Kinetic tremor
6. Rebound phenomenon
7. Nystagmus
8. Unsteady gait
1. Dysmetria
* Inability to adjust movement at certain distance
* The movement may:
- Hypermetria (Exceed than the distance)
- Hypometria (Less than the distance)
* Due to failure of predictive and damping function
2. Decomposition of movement
* Patient divides the complex movement into several steps to avoid need for precise timing required for joining the different complex movement
* Movement pattern may simulate the movement of robot
3. Dysdiadochokinesia
* Inability of person ton perform rapid alternating opposite movement (E.g. Supination and pronation)
* Movement becomes slow and irregular
* Due to failure of planning of sequence
4. Dysarthria
* Scanning or staccato speech
* Speech becomes slow and decomposed - Each word is fragmented
* Due to inability to adjust precise timing of contraction of different muscle of speech
5. Kinetic tremor
* Appear during voluntary movement
* Disappear during rest
6. Rebound phenomenon
* Inability of person to stop ongoing rapid movement
* The movement overshoots
* Due to failure of damping function
7. Nystagmus
* Due to tremors of eye ball on trying to fix on an object
* Due to failure of damping function of eye ball
8. Unsteady gait
* Gait is unsteady - Wide base resemble drunken person
* Due to dysmetria and kinetic tremors of lower limb muscles
4D KouTa Run iN Unsteady gait
• Dysmetria
• Decomposition of movement
• Dysdiadochokinesia
• Dysartheria
• Kinetic tremors
• Rebound phenomenon
• Nystagmus
• Unsteady gait
D&R
- Dysmetria, nystagmus, rebound phenomenon are due to failure of damping function.
FUNCTIONS OF CEREBELLUM
1. REGULATION OF EQUILIBRIUM
2. REGULATION OF POSTURE
3. REGULATION/ COORDINATION OF VOLUNTARY MOVEMENT
4. FUNCTION IN MOTOR LEARNING
5. FUNCTION IN RAPID & BALLISTIC MOVEMENT
1. Regulation of Equilibrium
2. Regulation of Posture
* Principal region concerned with postural adjustment is vermis
* Receives impulses from proprioceptors
* Adjust body posture via vestibulospinal and reticulospinal tracts
* Control tone of axial and proximal limb muscles
3. Regulation/ Coordination of Voluntary Movement
Coordination - Ability to proceed from one movement to another smoothly, precisely and in proper succession
Coordination is carried out by a number of mechanisms including:
a) Comparator and Error Corrector Mechanism
b) Predictive and Damping Mechanism
c) Planning Sequence and Timing Movement
a) Comparator and Error Corrector Mechanism
* When motor areas of cerebral cortex send motor commands to muscle, spinocerebellum receive an efference copy of intended motor activity via coticopontocerebellar pathway.
* In addition, ventral spinocerebellar pathway send to spinocerebellum another efference copy about signals that reached anterior horn cells of spinal cord.
* As movement proceed, dorsal spinocerebellar pathway send to spinocerebellum information about actual performance of muscle
* Intermediate zone of spinocerebellum compares the intended motor activity to actual performance of movement
* If there is any error in performance, spinocerebellum send corrective impulses to motor cortex which send impulses reaching muscle via descending motor tracts
b) Predictive and Damping Mechanism
* Cerebellum receives information regarding the velocity of intended movement from efference copy
* Sensory feedback signals from muscles and joints provide cerebellum with relative distance
* From these parameters, cerebellum determines the precise time to damp (Stop) the movement, then sends the decision to motor cortex to stop the ongoing movement exactly at intended position
c) Planning Sequence and Timing of Movement
i) Planning Sequence of Movement
- Cerebrocelebellum uses the information from cerebral cortex and basal ganglia for planning of sequence of contraction of different muscle involved in voluntary motor act to achieve goal of movement
- The plan is projected to motor areas of cerebral cortex
ii) Planning Timing of Movement
- Cerebrocerebellum provides perfect timing of voluntary movements determining the onset and termination of each muscle contraction for muscle involved performance of successive movement
- This allows for smooth progression of movement
4. Function in Motor Learning
* When a person first performs a complex motor action, the motor commands are uncoordinated
* After many trials cerebellum begins to coordinate movement so it becomes gradually more precise
* Specific motor program of movement is stored
5. Function in Rapid and Ballistic Movement
Ballistic movements
* Movements that are done very rapidly that it’s almost impossible to depend for their control on sensory feedback information from periphery because the movement would be over before such information reaches cerebellum and cerebral cortex
* Those movement are required for rapid writing, running and professional skills
* These movements are preplanned using stored programs that have been established by motor experiences
CLINICAL DISORDER OF CEREBELLUM
1. Folliculonodular Lobe Lesion
2. Vermal Disorders
3. Hemispherical Disorders
1. Folliculonodular Lobe Lesion
* Lesion leads to disturbance of equilibrium
* Manifested by:
- Swaying during standing with tendency to fall down
- Unsteady gait → Wide base to provide better support
2. Vermal Disorders
* Disturbs postural adjustment
* Patient is unable to maintain the upright standing posture
* Fail to adjust tone and contractility of antigravity muscles
3. Hemispherical Disorders
* Causes:
- Hemorrhage and thrombosis
- Tumours
* Usually destroys the intermediate and lateral zones of cerebellum
* Manifested as neocerebellar syndrome which is characterized by:
a) Hypotonia
b) Athenia
c) Ataxia
a) Hypotonia
- Due to decrease facilitation of gamma motor neuron
- Associated with hyporeflexia
- Knee jerk is characteristically pendular
b) Athenia
- Weakness of muscle
- Due to interruption of activating effect of cerebellum on motor cortex
c) Ataxia (Motor Ataxia)
Note: Go watch Ichi Litre no Namida for example of characteristic of ataxia
Definition: Uncoordination of voluntary movements
Characterized by: 4D KouTa Run iN Unsteady gait - D&R
1. Dysmetria
2. Decomposition of movement
3. Dysdiadochokinesia
4. Dysarthria
5. Kinetic tremor
6. Rebound phenomenon
7. Nystagmus
8. Unsteady gait
1. Dysmetria
* Inability to adjust movement at certain distance
* The movement may:
- Hypermetria (Exceed than the distance)
- Hypometria (Less than the distance)
* Due to failure of predictive and damping function
2. Decomposition of movement
* Patient divides the complex movement into several steps to avoid need for precise timing required for joining the different complex movement
* Movement pattern may simulate the movement of robot
3. Dysdiadochokinesia
* Inability of person ton perform rapid alternating opposite movement (E.g. Supination and pronation)
* Movement becomes slow and irregular
* Due to failure of planning of sequence
4. Dysarthria
* Scanning or staccato speech
* Speech becomes slow and decomposed - Each word is fragmented
* Due to inability to adjust precise timing of contraction of different muscle of speech
5. Kinetic tremor
* Appear during voluntary movement
* Disappear during rest
6. Rebound phenomenon
* Inability of person to stop ongoing rapid movement
* The movement overshoots
* Due to failure of damping function
7. Nystagmus
* Due to tremors of eye ball on trying to fix on an object
* Due to failure of damping function of eye ball
8. Unsteady gait
* Gait is unsteady - Wide base resemble drunken person
* Due to dysmetria and kinetic tremors of lower limb muscles
4D KouTa Run iN Unsteady gait
• Dysmetria
• Decomposition of movement
• Dysdiadochokinesia
• Dysartheria
• Kinetic tremors
• Rebound phenomenon
• Nystagmus
• Unsteady gait
D&R
- Dysmetria, nystagmus, rebound phenomenon are due to failure of damping function.