L25: Ataxia assessment and therapy options Flashcards
(84 cards)
1
Q
_____ takes 10% of the brain’s volume but has 50% of total neurons in the brain
A
Cerebellum
2
Q
What are 5 purposes of cerebellum?
A
- Maintenance of balance and posture
- Coordination of voluntary movements
- Motor learning
- Cognitive functions (language)
- Cerebellum is highly involved in central vestibular pathology
3
Q
What are 4 functional areas of the cerebellum that influence locomotion?
A
- Vermis (medial zone)
- Intermediate zone
- Lateral zone
- Flocculonodular lobe
4
Q
What are 4 afferents of the vermis (medial zone)?
A
- Vestibular afferents
- Vestibular nuclei
- Reticular & pontine nuclei
- Dorsal & ventral spinocerebellar tracts
- DSCT conveys information about the limbs
- VSCT conveys information about motor commands
5
Q
What is an efferent of the vermis (medial zone)?
A
Projects out to vestibular nuclei & reticular nuclei
6
Q
What are functions of the vermis (medial zone)?
A
Integration of spinal and vestibular inputs and influences motor pathways for walking
7
Q
What 2 lesions of the vermis (medial zone)?
A
- Damage to the vermis affects gait and sitting balance, with relative sparing of eye movements and speech
- Dizzy, altered eye movements, tone issues, verticality issues
- Medial zone: Alternative the locomotor pattern from sensory feedback from the limbs
8
Q
What are lesions of the cerebellum?
A
Damage to one cerebellar hemisphere usually causes ataxia in the ipsilateral limbs
9
Q
What are 3 afferents of the intermediate zone?
A
- DSCT and VSCT
- Reticular nuclei
- Cerebral cortex
10
Q
What are 2 efferents of the intermediate zone?
A
- Red nuclei
- Cerebral cortex
11
Q
What are functions of the intermediate zone?
A
Integration of spinal and cortical imputes to influence walking through projections to motor cortical areas
12
Q
What are 3 regulations of lesions of the intermediate zone?
A
Regulation of:
- Timing
- Amplitude
- Trajectory of elevation and descent
13
Q
What are 5 afferents of the lateral zone?
A
Cerebral cortex (via pontine nuclei)
- Primary motor
- Pre-motor
- Primary somatosensory
- Posterior parietal cortices
- Pre-frontal and temporal lobes
14
Q
What are 2 efferents (2) of the lateral zone?
A
- Red nucleus
- Cerebral cortex (via thalmus)
- Primary, pre-motor
- Parietal
- Prefrontal cortex
15
Q
What are functions of the lateral zone?
A
16
Q
What are 2 regulations of lesions of the lateral zone?
A
- Adjustments for novel contexts
- Adjustments when strong visual guidance is required.
17
Q
What are 3 afferents of the flocculonodular lobe?
A
- Primary vestibular afferents
- Vestibular nuclei
- Reticular nuclei
- Visual inputs
18
Q
What are 2 efferents of the flocculonodular lobe?
A
- Projects out to vestibular nuclei for control of eye
- Movements and balance
19
Q
What are lesions of the flocculonodular lobe?
A
Control of balance and locomotion
- Control extensor tone modulation control over rhythmic flexor/extensor activation
20
Q
What is the summary of the cerebellar?
A
- Inferior peduncle - vestib
- Superior & middle peduncle - motor
- Lateral nuclei get input from lateral hemisphere
- Medial nuclei get input from vermis & flocculonodular lobe
21
Q
What are 3 functions of the cerebellum as an integrator - controller - adaptor?
A
- Evaluates sensory input
- Modulates learning and outcomes
- Modify motor activity
22
Q
What are 2 functions of the cerebellum as influence?
A
- Functions in the somatomotor area
- Does not precipitate muscle activity
23
Q
What are 2 functions of the cerebellum as control?
A
- Influences purposeful movement
- Lesions create general movement decomposition (not paralysis)
24
Q
What are 7 cerebellum in tracking?
A
- Stabilise oscillating outputs
- Scaling of the amplitudes of the responses
- Improve speed and crispness of the response
- Proper distribution of the control commands across multiple inputs
- Reduction in systems output sensitivity to inward and outward influences.
- Predict explicitly the systems inputs and outputs
- Self-adaptation to adjust to changes in dynamics or environments.
25
What are 2 main blood supplies to the brain (cerebellum)?
1. Anterior circulation arising from internal carotids
2. Posterior (vertebrobasilar) circulation arising from subclavian artery
26
What are 3 things that the vertebrobasilar vascular system?
1. Brain stem
2. Cerebellum
3. Inner ear
27
What are 6 main branches for posterior circulation?
1. Vertebral arteries
2. Basilar artery
3. Posterior inferior cerebellar artery (PICA)
4. Labyrinthine artery
5. Anterior inferior cerebellar artery (AICA)
6. Superior cerebellar arteries (SCAs)
28
~ 20% of all TIAs and strokes arise from posterior circulation. Most common symptoms is \_\_\_\_\_/\_\_\_\_\_
dizziness/vertigo
29
What are 4 blood supply of the cerebral cortex?
1. Anterior cerebral artery (ACA)
2. Middle cerebral artery (MCA)
3. Posterior cerebral artery (PCA)
4. Anterior circulation CVAs cause light-headedness rather than vertigo
30
What is the origin for PICA as posterior circulation stroke?
Largest branch of vertebral artery
31
What are 2 supplies for PICA as posterior circulation stroke?
1. Lateral medulla, including vestibular nuclei
2. Posteroinferior cerebellum: Inferior cerebellar peduncle, nodulus & uvula
32
What is the stroke for PICA as posterior circulation stroke?
PICA stroke gives dizziness.
33
What is the origin for AICA as posterior circulation stroke?
Largest circumferential branches, arising from basilar artery
34
What are 5 supplies for AICA as posterior circulation stroke?
1. Labyrinth
2. Lateral pontine tegmentum
3. Brachium pontis
4. Flocculus
5. Part of anterior small branches to facial nerve
35
What are 3 strokes for AICA as posterior circulation stroke?
1. Typically involves middle cerebellar peduncle
2. Isolated vestibular infarction without cochlear involvement is rare
3. AICA stroke key sign is deafness and prolonged vertigo (\>24 hours)
* Most common pattern is peripheral and central oculomotor/vestibular signs
* Nausea/vomiting
* Dysarthria
* Nystagmus
* Gait ataxia Horner syndrome: Constricted pupil (miosis), drooping of upper eyelid (ptosis), no sweating on face (anhidrosis), and sinking of the eyeball (enophthalmos).
* Ipsilateral facial weakness and parasthesia
* Contralateral loss of heat and pain in body
* Ipsilateral cerebellar signs
* Sudden hearing loss +/- tinnitus (unilateral)
36
What are 9 other key symptoms for strokes for AICA as posterior circulation stroke?
1. Most common pattern is peripheral and central oculomotor/vestibular signs
2. Nausea/vomiting
3. Dysarthria
4. Nystagmus
5. Gait ataxia Horner syndrome: Constricted pupil (miosis), drooping of upper eyelid (ptosis), no sweating on face (anhidrosis), and sinking of the eyeball (enophthalmos).
6. Ipsilateral facial weakness and parasthesia
7. Contralateral loss of heat and pain in body
8. Ipsilateral cerebellar signs
9. Sudden hearing loss +/- tinnitus (unilateral)
37
What is the origin for labyrinthine artery as posterior circulation stroke?
Typically arises from AICA, but may arise from PICA or basilar artery
38
What are 4 supplies for labyrinthine artery (via) as posterior circulation stroke?
1. Common cochlear artery
2. Posterior vestibular artery (inferior saccule + posterior SCC)
3. Main cochlear artery
4. Anterior vestibular artery (utricle, part saccule, horizontal & anterior SCC)
39
What are 3 strokes for labyrinthine artery (via) as posterior circulation stroke?
1. Labyrinthine artery stroke affects peripheral vestibular apparatus.
2. If blood flow stops for 15 secs, the auditory nerve fibres become unexcitable
3. Labyrinth is more vulnerable to ischaemia than brainstem or cerebellum because it has less collateral arteries.
40
What is the origin for SCA as posterior circulation stroke?
Arises from basilar artery
41
What are 2 supplies for SCA as posterior circulation stroke?
1. Superior cerebellar hemisphere and vermis
2. Superior cerebellar peduncle
42
What are 8 strokes for SCA as posterior circulation stroke?
1. Gait ataxia with sudden falls
2. Limb dysmetria
3. Mild vertigo ~50%
4. Dysarthria
5. Spontaneous nystagmus ipsilesionally (suppressed by fixation)
6. Saccadic contrapulsion: Saccades overshoot away
7. from, and undershoot toward, the side of lesion
8. Attempted vertical saccades are oblique
43
What are 2 features of Wallenberg’s Syndrome?
1. Lateral medullary deficit (PICA)
2. Roll plane deficit: Torsional nystagmus, skew deviation, ocular torsion, tilts of head, body and perceived vertical
44
What are 7 Oculomotor Findings in LMI?
1. Lateropulsion of the eyes
2. Lateropulsion of horizontal saccades (ipsipulsion)
3. Lateropulsion of vertical saccades
4. Torsipulsion during horizontal saccades
5. Impaired smooth pursuit (saccadic intrusion) for targets moving away from side of lesion
6. Spontaneous nystagmus
7. Ocular tilt reaction (OTR)
45
What is ataxia?
Ataxia is a lack of muscle coordination during voluntary movements.
46
What are 3 signs of cerebellar pathology?
1. Dysmetria
2. Dyssergenia
3. Dysdiadochokinesia
47
What is dysmetria?
Inaccuracy in achieving target
48
What is dyssergenia?
1. Finger nose finger test
2. Delayed and sluggish force development/cessation
3. Impairment of scaling of force amplitude
4. Degradation of multi-joint coordination
5. **Astasia:** Difficulty with maintaining upright Balance/postural regulation
6. **Abasia:** Difficulty with maintaining any multi-joint movement in locomotion
49
What is astasia?
Astasia: Difficulty with maintaining upright Balance/postural regulation
50
What is abasia?
Abasia: Difficulty with maintaining any multi-joint movement in locomotion
51
What is dyssergenia?
Muscle activation order suboptimal
52
What are 3 features of dyssergenia?
1. Accelerations of different joints are not scaled properly to each other
2. Veering from the path of movement
3. Heel shin test
53
What is dysdiadochokinesia?
Inability to perform movements of constant force and rhythm
54
What is tremour?
Tremor is rhythmic involuntary oscillating movement of a body part
55
What is resting tremour?
Involuntary and occurs in body part supported by gravity
* PD has resting tremor
56
What is active tremour?
occurs during movement against gravity
1. Intention tremor
2. Postural tremor: Titubation - oscillation is often worse with intent Movement - may be a force generation/modulation error loop?
3. Kinetic tremor
4. Isometric tremor
5. Cerebellar pathology has action/intention tremor
6. Olivopontine nuclei infarct has soft palate tremor
57
What are 6 abnormal eye movements?
1. Divergent nystagmus
2. Centripedal nystagmus
3. Upbeating nystagmus
4. Pendular nystagmus
5. Periodic alternating nystagmus - inconsistent rhythm
6. Rebound nystagmus
58
What are 3 other signs of cerebellar pathology?
1. Serial dysmetria
2. Disdiadokokinesia - timing and rhythm issue
3. Impaired inter-joint synchronization
59
What are 4 saccades as abnormal eye movements?
1. Hypometric: Large and small, long and short
2. Hypermetric
3. Macrosacaddic oscillation is often associated with limb dysmetria and postural tremor
4. Pulse-step mismatch
60
What are 3 features of speech as abnormal eye movements?
1. Dysarthria
2. Slow
3. Scanning
61
What are 2 features of smooth pursuit as abnormal eye movements?
1. Saccadic intrusions during tracking
2. Not specific to cerebellar lesion
62
What are 2 features of VOR as abnormal eye movements?
1. Reduced VOR: HIT abnormalities from cross disinhibition
2. VOR cancellation
63
What are 2 areas of learning for motor learning impairments?
1. **Simple responses**: Cerebellar error creates a primitive reweighting of a response to be protective
2. **Complex adaptive process** linkages between cerebellar and cerebral for learning.
3. Takes many repetitions
Cerebellum is responsible for continuous control of movement dynamics and transitions.
Cerebrum focuses on revising in real-time and storing the kinematic plan
64
\_\_\_\_\_\_ is responsible for continuous control of movement dynamics and transitions. Cerebrum focuses on revising in ______ and storing the \_\_\_\_\_\_\_.
Cerebellum; real-time; kinematic plan
65
Pure cerebellar pathology spares cognition & perception, but many patients report reduced control of \_\_\_\_\_, _____ and ______ abilities.
cognitive, perception; timing
66
What are 6 features of reduced capacity as perceptual and timing impairments?
1. Evaluate events
2. Implement actions at short time intervals
3. Certain executive, language and high-demand memory tasks
4. Perceive time events
5. Perceive movement events
6. Perceive differences
67
What are 4 features of Cerebellar Cognitive Affective Syndrome (CCAS) for cognitive and affective impairments?
1. Impaired executive function: Working memory, planning, set shifting, verbal fluency, and abstract reasoning
2. Visuospatial disorganization
3. Language deficits including agrammatism and dysprosodia
4. Personality change including flattening of affect and mutism.
68
Cerebellum has extensive facilitation on many areas of the cerebral cortex. What are 2 features?
1. Acute failure will reverse cerebellar disaschisis or crossed cerebello-cerebral diaschisis
2. Recovery can occur from other brain areas to "restore" facilitation
69
What is cerebellar neurodegenerative pathology?
Cerebellar neurons deteriorate/die.
* Diseases that result in cerebellar degeneration can also involve other areas of CNS.
70
What are 7 Causes of Cerebellar Neurodegenerative Pathology?
1. Inherited genetic mutations
2. Acquired genetic mutations
3. Acquired degeneration (idiopathic)
4. Toxicity
5. Infection
6. Immunological
7. Inherited
71
What are 2 types of Inherited & Acquired Genetic Mutations?
1. Spinocerebellar ataxia (SCA): ~38+ mutations identified
2. Spinocerebellar ataxia recessive (SCAR): Autosomal recessive - often linked to one family
72
What are 5 features of Spinocerebellar Ataxia (SCA)?
1. Group of disorders affecting cerebellar afferent and efferent pathways within and outside cerebellum
2. Symptoms of SCA
1. Slowly progressive, symmetrical, midline and appendicular ataxia
2. Affecting eye movement, speech, swallow, limb coordination, posture and gait
3. Clinical DDx is very difficult
4. Incidence: 1-5/100,000 (SCA-3 most common)
5. Genetics
* Genetically heterogeneous
* Autosomal dominant
* ~38+ genetic mutations identified
* 1-3, 6,7,10,12-14,17 & 27 translated CAG repeat mutation coding for an elongated polyglutamine tract within the respective protein
73
What are Toxicity Causes of Cerebellar Neurodegenerative Pathology?
Acute to chronic toxicity
74
What are 4 symptoms of Alcohol toxicity for Cerebellar Neurodegenerative Pathology?
1. Bilateral ataxia (LL \> UL)
2. Gait and trunk
3. Altered eye movements: Wernicke’s encephalopathy due to thiamine deficiency - usually long term but can be seen in alcohol poisoning
4. Less common signs: Altered mentation
75
What are 2 types of sub-acute to chronic infections as Infectious Causes of Cerebellar Neurodegenerative Pathology?
1. Miller Fisher variant of Guillain Barre - immune mediated
2. Cerebellitis & rhombencephalitis (in children)
76
What are 6 symptoms of Miller Fisher variant of Guillain Barre of sub-acute to chronic infections as Infectious Causes of Cerebellar Neurodegenerative Pathology?
1. Bilateral ataxia Gait and trunk ataxia
2. General ataxic signs
3. Ophthalmoplegia
4. Areflexia
5. Altered eye movements
77
What are 8 symptoms of Cerebellitis & rhombencephalitis (in children) of sub-acute to chronic infections as Infectious Causes of Cerebellar Neurodegenerative Pathology?
1. Bilateral ataxia
2. Gait and trunk ataxia
3. General ataxic signs
4. Altered mentation
5. Cranial nerve involvement
6. Headache
7. Vertigo/dysequilibrium
8. Altered eye movements.
78
What is a type of chronic infections as Infectious Causes of Cerebellar Neurodegenerative Pathology?
Creutzfeld-Jakob disease (CJD)
79
What are 5 symptoms of Creutzfeld-Jakob disease (CJD) of chronic infections as Infectious Causes of Cerebellar Neurodegenerative Pathology?
1. Dysarthria
2. Generalised ataxia
3. Multi-system involvement
4. Cognitive decline
5. Occulomotor abnormalities
80
What are 6 symptoms of Paraneoplastic syndrome as Immunological Causes of Cerebellar Neurodegenerative Pathology?
1. Immune mediated - 7-10 years after chemo
2. Bilateral
3. Gait and trunk ataxia
4. General ataxic signs
5. Vertigo/dysequilibrium
6. Altered eye movements
81
What are 6 symptoms of Cerebellar Ataxia, Neuropathy, Vestibular Areflexia Syndrome (CANVAS)?
1. Late onset
2. Cerebellar atrophy of anterior and dorsal vermis.
3. Sensory neuropathy non-length dependent
4. Bilateral vestibular impairment - altered eye movements
5. Diagnosis by exclusion
6. No treatment
82
What are 3 symptoms of Spontaneous Adult Onset Ataxia (SAOA)?
1. Onset after 20 yos. Mostly females 50-60 yos.
2. No acute or subacute disease onset
3. No known pathological construct
* No causative gene mutation
* No symptomatic cause
* No possible MSA according to established clinical criteria
83
What are 6 Clinical Presentation of SAOA?
1. Ataxia of gait and trunk
2. Dysmetria of limbs
3. Heel shin test universally positive.
4. Dysdiadochokinesia of limbs
5. Dysarthria
6. Abnormal oculomotor
* Broken-up smooth pursuit
* Gaze-evoked nystagmus
* Saccadic dysmetria
* Positive VOR cancellation test
84
What are 7 Non-Cerebellar Features of SAOA?
1. Sensory loss
2. Pyramidal weakness
3. Absent reflexes
4. Reduced vibration sense
5. Increased bladder frequency
6. Mild autonomic (reduced HR variability) - measure RPE not HR in exercises
