Theme 2 - Sensory Inputs and Motor Outputs Flashcards
1
Q
An ipsilateral lesion to the dorsal medial leminscus tract spinal cord (for example in MS) will result in what?
A
loss of propriception on the same side
2
Q
What is a loss of coordination and balance without visual cues known as?
A
sensory ataxia
3
Q
What is the test/sign for sensory ataxia?
A
Rombnerg’s sign - severe swaying on standing with eyes closed and feet together
4
Q
An ipsilateral lesion to the white matter anterolateral column will result in what?
A
Loss of pain, temperature and crude touch on opposite side
5
Q
What will an ipsilateral lesion to the posterior spinocerebellar tract cause?
A
Loss of lower limb muscle coordination on the same side
6
Q
3 symptoms associated with upper motor neuron disease
A
Spastic paralysis
Overactive tendon reflexes
No significant atrophy
7
Q
If there is a degeneration of upper motor neurons above the pyramids which side will it mainly affect?
A
opposite side
8
Q
Three features of lower motor neuron disease
A
Flaccid paralysis
No tendon reflexes
Atrophy
9
Q
What does amyotrophic lateral sclerosis (Lou Gehrigs disease) affect?
A
progressively and selectively affects both lower and upper motor neurons
10
Q
What three things will be affected in anterior cord syndrome?
A
Bilateral lower motor paralysis and atrophy (lower motor neurons
Bilateral spastic paralysis descending anterior tracts
Loss of pain, temperature and fine touch
11
Q
What sensation remain intact during anterior cord syndrome
A
proprioception
tactile descrimination
vibration
12
Q
5 effects of Brown-Sequard hemisection?
A
ipsilateral paralysis and atrophy (lower motor)
ipsilateral spastic paralysis (upper motor)
ipsilateral anesthesia at lesion level (dorsal root)
ipsilateral loss of proprioception
contralateral loss of pain, temp and light touch
13
Q
4 Effects of complete cord transection
A
Complete loss of sensation and voluntayy movement below transection site
Bilateral lower motor neuron paralysis and atrophy
Bilateral spastic paralysis
Bladder and bowel non voluntary
14
Q
Outline the motor control hierarchy in terms of associated areas of the brain (high to low)
A
Association areas of neocortex, basal ganglia
Motor cortex/cerebellum
Brainstem/spinal cord
15
Q
What are the 5 descending motor pathways?
A
Corticospinal Rubrospinal Reticulospinal Tectospinal Vestibulospinal
16
Q
Where does the corticospinal tract begin, dessucate and synapse?
A
Motor cortex
Medullary pyramids
Lateral CS tract
17
Q
Where does the Rubrospinal tract begin, dessucate and predominantly end up?
A
Red nuclei in midbrain
Medulla
Cervical junction
18
Q
Where does the vestibular spinal tract begin and where do they go?
A
Medial and Lateral vestibular nucleus in brainstem
Med - neck muscles
Lateral - Limbs
19
Q
What does the vestibular muscles facilitate?
A
Keeping a steady gaze
Steady balance and posture
20
Q
From where does the Tectospinal tract originate?
A
Superior and inferior colliculi
21
Q
What does the tectospinal tract from each collucili help you to do?
A
Superior collucili - instant neck and head muscle responce to fast visual stimulus
22
Q
Where does the reticulospinal tract originate and what is it associated with?
A
Reticilum (back) of brainstem and aid with posture
23
Q
What descending pathways are associated with control of head and neck movements?
A
Tectospinal and medial vestibulospinal
24
Q
What descending pathways are associated with control of limb extension?
A
Lateral vestibulospinal and reticulospinal
25
What descending pathway is associated with flexion of upper limbs?
Rubrospinal
26
In a coma pt, what type of posturing will result in them flexing their arm and either flexing or extending their leg?
decorticate posturing
27
In a coma pt what type of posturing will result in them extending both their arms and legs?
decerebrate
28
What indication do decorticate and decerebrate posturing give about the location of the lesion?
decorticate - above red nucleus (Rubrospinal tract intact)
| decerebrate - below red nucleus
29
Does the babinski reflex indiacate an upper or power motor neuron lesion?
Upper
30
Where does the corticobulbar pathway go from/to?
motor cortex to cranial nerves
31
What is the difference in terms of lesion localisation and facial palsy between a stroke and Bells palsy?
Stroke - upper motor neurone, contralateral lower half
| Bell's - lower motor neurone, ipsilateral, full half
32
What is abulia?
Loss or impairment of the ability to make decisions or act independently
33
A stroke associated with what type of artery is most likely to result in abulia?
Anterior cerebral
34
What type of seizure is associated with a "march" of symptoms?
Jacksonian
35
What can damage to the posterior parietal cortex result in?
neglect - can perceive but not attend
36
What pathways are associated with the posterior parietal cortex?
somatosensory afferent
| visual afferent
37
Damaged to the interconnections between the sensory and motor coordination areas is likely to result in what?
Apraxia
38
What term describes a difficulty in sequencing and execution of movements?
Apraxia
Aphagia
Anosia
Apraxia
39
What is the difference between ideational and ideomotor apraxia and what areas of the brain are they assocoated with?
Ideational (parietal) cannot report sequence
| Ideomotor (SMA) - cannot use the tool
40
What condition is best described as sustained muscle contractions, usually producing twisting and repetitive movements or abnormal postures or positions.
If only occurs with certain actions, said to be ‘task specific’.
dystonia
41
3 functions of the cerebellum
Maintenance of balance and posture
Coordination of voluntary movements
Motor learning
42
What are the 3 main inputs into the cerebellum and what area do they feed into?
vestibulocerebellum - flocculonoddular
cerebrocerebellum - hemispheres
spinalcerebellum - vermis
43
to what nuclei do the vermis, paravermis and hemispheres link?
vermis - fastigial
paradermis - interposed
hemispheres - dentate
44
To what other areas of the brain are the cerebellar fastigial, interposed, dentate and vestibular nuclei linked to?
Fastigial - motor
interposed - motor
dentate - motor planning
vestibular - balance and eye movements
45
4 Steps of the spinocerebellum loop
spinocerebellar tract
vermis
fastigial/interposed nuclei
reticulo/vestibularspinal tract
46
6 steps of the corticocerebellum loop
```
cortex
pons
hemispheres
dendate nucleus
thalamus
cortex
```
47
4 steps of vestibulococlear loop
vestibulocochlear
fluculonodular node
vestibular nuclei
eyes/neck muscles
48
What are the 3 cerebellar peduncles and are they inputs or outputs?
Superior - output
Middle - input
Inferior - input
49
What tracts input via the inferior and middle cerebral peduncle?
inf - Spinocerebellar
| mid - corticocerbellar
50
What tracts output via the superior cerebral peduncle?
vestibulocerebellar
corticocerebellar
spinocerebellar
51
5 effects of lesions on the cerebrocerebellar pathway
```
dysmetria
dysnergia
disdisdochokinesia
intentional tremor
dysarthria
```
52
What term is defined as the inability to stop a movement in time?
Dysmetria
53
What term is defined as decomposition of complex movements?
Dsynergia
54
What term is defined as reduced ability to perform rapidly alternating movements?
Dysdiadochokinesia
55
What is an intentional tremor?
tremor arising when trying to perform a goal-directed movement
56
What term is defined as incoordination in the respiratory muscles, muscles of the larynx, etc. Uneven speech strength and velocity?
Dysarthria
57
What are the 2 effects of lesions on the vestibulo occular pathway?
Nystagmus
| Inability to fixate when moving
58
What is the effect of lesion on the spinocerebellar pathway?
gait ataxia
59
What term is defined as involuntary, rhythmical, repeated oscillations of one or both eyes, in any or all directions of view?
Nystagmus
60
What two types of fibre input into the cerebellum and where do they come from?
Mossy fibres - spinal tract
| climbing fibres from - inferior olive of medulla
61
```
Describe/draw the cerebellar circuit in terms of
mossy fibres,
climbing fibres
granule cell
parallel cell
purkunje cell
```
mossy to granule to parallel to perkunje
| climbing to perkunje
62
Give 2 genetic causes of cerebellar dysfunction
Frederich’s ataxia
| Spinocerebellar degeneration
63
5 causes of acquired symmetrical ataxia
```
Alcohol
drugs
metabolic (B12)
degenerative
Immune
```
64
What 3 types of tissue are innervated by the ANS?
Smooth muscle
cardiac
glands
65
What are the 3 divisions of the ANS?
sympathetic
parasympathetic
enteric
66
In terms of the CNS what are anatomical divisions of the sympathetic and parasympathetic nervous systems?
Para - brainstem, S1-S4
| sym - T1 - L2
67
The ANS works via a disynaptic pathway in all but one effector organ, which one?
adrenal glands
68
```
Explain/draw the disynaptic pathway i terms of
cranial nerve
ganglion
effector organ
myelenated
unmylenated
```
as described
69
What is the main neurotransmitter in the preganglionic ANS?
Ach
70
What are the three ascending pathways in the spinal cord?
Spinothalamic (anterolateral)
spinocerebellar
dorsal columns (medial lemniscus)
71
What neurotransmitters used (post ganglion) by the sympathetic and para sympathetic nervous system?
sym Noradrenaline/NE
| para - Ach
72
What type of receptors are employed by the sympathetic and para sympathetic nervous system pre and post ganglion?
ganglion - nicotinic Ach
| post - G protein metabotropic (except adrenal medulla)
73
What are the two plexuses that make up the enteric nervous system and what do they regulate?
Auerbach's - muscle contraction
| Meissner's - secretions
74
What are the two possible pathways of the preganglionic fibres once they enter the sympathetic trunk?
Synapse in ganglion
| Pass through ganglion in splancnic nerves and synapse in prevertebral ganglia
75
Post ganglionic fibres are more numerous than preganglionic fibres, what is the advantage of this?
It allows for a mass response
76
What are the two possible pathways of the POSTganglionic fibres once they exit the sympathetic trunk?
To periphery via grey rami
| To viscera via plexuses
77
What are the 3 ganglia in the cervical trunk, and what's special about one of them?
Superior
Middle
Inferior - fussed to T1 ganglia to form stellate
78
What are the 3 possible routes for the postganglionic fibres in the cervical sympathetic trunk?
via grey rami to spinal nerves and upper limbs
piggy back down carotid artery to heart
Or up internal/external carotid to head
79
What condition is the disruption of sympathetic nervous supply to the head?
Horners syndrome
80
What are the 3 possible routes of the postganglionic fibres in the thoracic sympathetic trunk?
grey rami to spinal nerves
medial branches to heart and lungs
splancnic nerves to abdomen
81
What cranial nerves are associated with the parasympathetic nervous system
III
VII
IX
82
5 sensations of pain
Sharp stab
Deep Ache
Burning
Freezing Itch
83
3 classifications of pain
Nociceptive
Infalmmatory
Neuropathic
84
Describe A alpha and A beta fibres in terms of myelenation, diameter and sensation conveyed
Myelenated
Thick
Light touch, proprioception
85
Describe A delta fibres in terms of myelenation, diameter and sensation conveyed
Thinly myelenated
medium
light touch, temperature nociception
86
Describe C fibres in terms of myelenaations, diameter, ans sensation
Unmyelenated
thin
temperature, nociception
87
What are the types of nerve fibre involved in pain transmission
Alpha delta
| C fibres
88
What type of pain is conveyed by each type of pain fibres?
Alpha delta - sharp prick
| C fibres - dull ache
89
At what point on the pain transduction graph is the first and second response?
First large peak = A beta
First small peak = first response from A delta
last small peak = second response from C fibres
90
Which transient potential receptor is responsible for detecting heat?
TRPV1
91
Via what tract does pain ascend the spinal cord?
spinothalamic tract
92
How does referred pain occur with regard to synapsing of neurons?
because the first order neurons of the vicera and cutaneous synapse on the same second order neuron
93
What 2 regions involved in the descending regulation of pain?
```
PAG (midbrain)
Raphe nucleus (medulla)
```
94
What effect can the Raphe nucleus have on the spinothalamic tract?
Either excite or inhibit.
| So increase or decrease pain
95
2 examples of opioids that play a role in descending inhibition of pain
Enddorphins
| Enkephalins
96
What receptors do opioids act upon?
Inhibitory metabotropic receptors
97
Give 3 sites from which opioids are released from
PAG - midbrain
Raphe - medulla
Dorsal horn
98
Give 3 inflammation related chemical that can activate nociceptors
ATP
H+
Serotonin
99
What 2 substances are related to neurogenic inflammation?
Substance P
| CGRP
100
What term is defined as a non-noxious stimuli producing a painful response?
Allodynia
101
What term is defined as a noxious stimuli producing an exaggerated pain response?
Hyperalgesia
102
With regard to pain hypersensitisation what will peripheral and central sensitisation result in?
Peripheral - primary hyperalgesia
| central - allodynia
103
How do bradykinin and NGF influence peripheral nerves sensitisation?
reduce threshold of heat activated channels
104
What are the 6 components of the basal gangia?
```
Putamen
Globus Pallidus Internal
Globus Pallidis External
Caudate nucleus
Substantia Nigra
Subthalmaic nucleus
```
105
What makes up the striatum of the basal gangia?
Caudate nucleus
| Putamen
106
Draw the direct pathway of basal ganglia 5
```
Cortex
Striatum
GPi
Thalamus
COrtex
```
107
Draw the indirect pathway 7
```
Cortex
Striatum
GPe
Subthamic nucleus
GPi
Thalamus
Cortex
```
108
Draw the hyperdirect pathway
Cortex
Subthalmic nucleus
GPi
109
What are the different types of dopamine receptor on medium spiney neurons in basal ganglia and what effect do they have on excitation?
D1 - ramp up excitation
| D2 - dampen down excitation
110
On what pathways are D1 and D2 receptors founnd in the basal ganglia and what effect do they have upon excitation?
D1 - direct - ramp up
| D2 indirect - damp down
111
Does the release of dopamine from substantia nigra inhibit or promote movement?
Promote
112
What neurotransmitter opposes the effects of dopamine upon the medium spiney neurons?
Ach
113
What condition is described as a A high amplitude flailing of the limbs on one side of the body?
Ballisimus
114
Where on the direct/indirect pathway is affecting in ballismus and what us the commonest cause
Subthalmic nucleus
| Stroke
115
What makes tic disorders worse/better?
Anxeity and fatigue
| Distraction and concentration
116
Possible causes of tic disorders
Post infectious
| genetic
117
What condition is described as a Jerky, brief, irregular contractions that are not repetitive or
rhythmic, but appear to flow from one muscle to the next?
Chorea
118
Commonest causes of chorea?
Huntingtons
| Neuropeltic drugs
119
The three areas impacted by Huntingtons
Cognitive - inability to plan
Behavioural - irritable, depression, anxiety
Motor - chorea
120
What disorder is Brief movement rapid onset and offset
| Positive (muscular contractions) or negative (muscular inhibitions)
Myoclonus
121
£ common causes of myoclonus
Juvenile Myoclonic Epilepsy
Brain hypoxia
Prion disease
122
What condition is defined as abnormal twisting posture – often axial/ facial/ truncal, may be associated with jerky tremor
Dystonia
123
5 possible causes of dystonia
```
Stroke
Brain injury
Encephalitis
Huntington's
Parkinson's
```
124
3 types of treatment for hyperkinetic disorders
D2 blocking agents - haloperidol
Dopamine depleting agents - reserpine
Atypical antipsychotics - clozapine
125
3 Key side effects of dopamine blocking drugs
Oculogyric crisis - acute
Neuroleptic malignant syndrome
Drug induced Parkinsonism
126
3 features of neuroleptic malignant syndrome
Rigidity - raised CPK
Fever/Confusion
Autonomic instability
127
What condition involves lip smacking, tongue and cheek movements?
tardive dyskinesia
128
Treatment of tardive dyskinesia? 4
gradual withdrawal
substitute with atypical antipsychotic
dopamine depleting agent
use of benzodiazapine
129
Type of tremor that comes with Parkinson's?
Resting tremor
130
5 Non motor symptoms of Parkinson's?
```
Dementia
Depression
Postural hypotension
Sleep disturbance
Reduced sense of smell
```
131
4 non neurodegenerative causes of parkinson's?
Drugs - haloperidol
Cerebrovascular disease
Hydrocephalus
Toxicity
132
Two examples of Monoamine oxidase Inhibitors and what can they be used to treat?
Selegiline
Rasagiline
For parkinson's
133
Mechanism of action for lidocaine?
sodium channel blocker
134
How does Topical capsaicin treatment work for the treatment of acute pain?
TRPV1 agonist
Repeated use reduces nocicpetor firing
Peripheral terminals die back
135
How do NSAIDs reduce inflammation and therefore pain?
COX inhibited
Reduce prostaglandin synthesis
prevent's decrease in sodium channel threshold
136
What is the mechanism of action for opoids and 3 sites of action?
Agonists for endogenous opoid system
Brainstem
Spinal cord
Peripheral
137
These statements refer to what pain related theory?
Modulation of pain at the spinal cord level
Pain evoked by nociceptors can be reduced by simultaneous activation of low threshold mechanoreceptors (Aβ fibres)
Gate control theory
138
2 peripheral mechanisms of chronic pain?
1. Peripheral sensitization
| 2. Spontaneous firing of nociceptors
139
In chronic pain what causes the spontaneous firing of nociceptors following a nerve injury?
Accumulation of ion channels at regenerating tip of axon
140
What is the mechanism for central sensitisation on chronic pain?
Due to the reduced threshold for activation of 2nd order neurons
141
WHat are the 6 steps for reducing threshold for activation in chronic pain?
Constant firing of axons from the periphery (following injury) gives a Sustained release of glutamate
Prolonged depolarisation of the postsynaptic membrane
Massive influx of Ca2+ through NMDA receptors
Activation of kinases
Phosphorylation of NMDA/AMPA receptors
Channel protein synthesis
142
What is the mechanism for central hyperalgesia?
Activation of nociceptors results in amplified spinal cord activation
143
What is the mechanism for central allodynia?
Non-noxious Aβ fibres also synapse onto 2nd order spinothalamic neurons
Following central sensitization:
Non-noxious afferents activate sensitized 2nd order neurons
144
3 types of drugs that can treat chronic pain?
- Tricyclic antidepressants
- Anticonvulsants
- NMDA antagonists
145
AN example of tricyclic antidepressant>
Amitriptyline
146
Example of an anticonvulsant
carbamazepine
147
Example of an NMDA antagonist and mechanism of action?
ketamine
- NMDA receptor antagonist (reduces glutamate influx)
- Prevents depolarization of second order neuron
