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Semester 3: Mind and Movement > PBL Topic 3 Case 5 > Flashcards

PBL Topic 3 Case 5 Flashcards

1
Q

Identify two types of sensory relay neurons located in the grey matter of the spinal cord

A
  • Anterior motor neurons

- Interneurons

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2
Q

Identify two types of anterior motor neurons and what each type innervates

A
  • Alpha motor neurons, which innervate the extrafusal muscle fibres
  • Gamma motor neurons, which innervate intrafusal muscle fibres
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3
Q

What are interneurons?

A
  • Neurons found exclusively in the CNS

- Transmit signals from the brain to anterior motor neurons

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4
Q

What is the function of Renshaw cells?

A
  • Anterior motor neurons give off branches to Renshaw cells
  • Which are inhibitory cells that send inhibitory signals to surrounding motor neurons (lateral inhibition)
  • To sharpen or focus signals to motor neurons
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5
Q

What are propriospinal fibres?

A
  • Collections of nerve fibres that run ascending/descending/crossed/uncrossed
  • That interconnect all levels of the spinal cord
  • Providing pathways for multisegment reflexes that co-ordinate simultaneous movements
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6
Q

Identify two types of muscle sensory receptors and they sensory information that they provide

A
  • Muscle spindles, located in the belly of the muscle, providing information about muscle length or rate of change of length
  • Golgi tendon organs, located in muscle tendons, providing information about tendon tension or rate of change of tension
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7
Q

Identify two sensory endings of a muscle spindle, what type of fibre they are and where they are positioned

A
  • Annulospiral / Primary ending, type Ia fibre that encircles the central portion of the intrafusal fibre
  • Flower Spray / Secondary ending, type II fibre that innervates both sides of the primary ending
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8
Q

Identify the two types of intrafusal fibres

A
  • Nuclear bags, fibres are congregated into expanded bags in the central portion of the receptor area
  • Nuclear chains, fibres are smaller and have nuclei aligned in a chain throughout the receptor area
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9
Q

Which intrafusal fibre(s) excite primary sensory endings of the muscle spindle

A
  • Nuclear bag

- Nuclear chain

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10
Q

Which intrafusal fibre(s) excite secondary sensory endings of the muscle spindle

A
  • Nuclear chain
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11
Q

What is the static response of a muscle spindle?

A
  • Muscle spindle is stretched slowly
  • Impulses increase in direct proportion to degree of stretching
  • From both primary and secondary nerve endings
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12
Q

What is the dynamic response of a muscle spindle?

A
  • Muscle spindle length increases suddenly

- The primary endings are stimulated but the secondary endings are not

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13
Q

Identify the two type of gamma motor nerves

A
  • Gamma-dynamic nerves, which excite mainly nuclear chain intrafusal fibres
  • Gamma-static nerves, which excite the nuclear chain fibres, greatly enhancing the static response
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14
Q

What is the difference between positive and negative signals from muscle spindles?

A
  • Positive signals involve increased numbers of impulses to indicate stretch of a muscle
  • Negative signals involve decreased numbers of impulses to indicate that the muscle is not stretched
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15
Q

Describe the basic circuit of the muscle spindle stretch reflex

A
  • Type Ia nerve fibres from muscle spindle enter the dorsal root of the spinal cord
  • One branch goes to anterior horn of grey matter to synapse with anterior motor neurons
  • That send motor nerve fibres back to the same muscle from which the muscle spindle fibre originated
  • Type II fibres on the other hand terminate on interneurons which transmit delayed signals to the anterior motor neurons
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16
Q

What is the damping function?

A
  • Signals from the spinal cord are transmitted to a muscle in an unsmooth form
  • The stretch reflex allows smoothening of muscle contractions
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17
Q

What is co-activation of motor neurons and what is its importance?

A
  • Activation of alpha motor neurons involves simultaneous activation of gamma neurons
  • So that both the extrafusal skeletal muscle fibres and the intrafusal spindle fibres contract at the same time
  • It keeps the muscle spindle reflex from opposing the muscle contraction (by keeping the length of the receptor portion the same during whole muscle contraction)
  • It also maintains the damping function of the spindle
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18
Q

The gamma efferent system is excited by signals from which area?

A
  • Reticular formation, giving rise to reticulospinal tracts
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19
Q

Identify the pathways taken by the pontine and medullary reticulospinal tracts

A
  • Pontine reticulospinal tract descends ipsilaterally in the anterior funiculus
  • Medullary reticulospinal tract descends partly crossed in the lateral funiculus
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20
Q

Which neurons does the pontine reticulospinal tract act upon?

A
  • Extensor motor neurons
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21
Q

Which neurons does the medullary reticulospinal tract act upon?

A
  • Flexor motor neurons
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22
Q

What are the two kinds of motor behaviour that the reticulospinal tract is involved in?

A
  • Locomotion

- Postural control

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23
Q

What is clonus and what causes clonus?

A
  • Oscillation of a muscle jerk

- Caused by sensitisation of facilitatory impulses from the brain

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24
Q

When is the Golgi tendon organ stimulated?

A
  • When the small bundle of muscle fibres is tensed by contracting or stretching of the muscle
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25
Q

Golgi tendon organs transmit through which type of fibres?

A
  • Type Ib fibres
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26
Q

Identify two signal pathways from the Golgi tendon organ

A
  • Via the spinocerebellar tracts and through other tracts to the cerebral cortex
  • Local areas of the cord which excite inhibitory interneurons that inhibit the anterior motor neurone
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27
Q

What is the lengthening reaction?

A
  • Golgi tendon is stimulated by increased tension
  • Inhibitory signals to spinal cord to prevent excessive tension on the muscle
  • That would otherwise causing tendon or avulsion of the tendon
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28
Q

What is the flexor reflex?

A
  • Stimulation of pain nerve endings on a limb, signals enter the dorsal horn of the spinal cord
  • Synapse with anterior motor neurons that send motor nerve fibres to flexor muscles
  • This withdraws the limb from the painful stimulus
  • With reciprocal inhibition circuits for antagonist muscles
  • After discharge, which depends on the intensity of the sensory stimulus
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29
Q

What is the crossed extensor reflex?

A
  • Extension of opposite limb that the flexor reflex takes place in
  • To push the entire body away from the object causing the painful stimulus
  • Signals from sensory nerves cross to the opposite side of the cord via interneurons to anterior motor neurons that to excite extensor muscles
  • Even longer duration after discharge duration
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30
Q

Identify the three subareas of the motor cortex that are involved in specific motor functions

A
  • Primary motor cortex
  • Premotor area
  • Supplementary motor area
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31
Q

Where is the primary motor cortex located?

A
  • Precentral gyrus

- Broadmann’s area 4

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32
Q

Outline the topographical representations of the different muscle areas in the primary motor cortex

A
  • Face and mouth near lateral fissure
  • Arm and hand in the mid-portion (large portion)
  • Trunk near the apex of the brain
  • Leg and foot areas, near the longitudinal fissure
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33
Q

Where is the premotor area located?

A
  • Anterior to the primary motor cortex
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34
Q

What is the function of the premotor area?

A
  • Develops a motor image of complex patterns of movement associated
  • Sends fibres directly to primary motor cortex or to basal ganglia and thalamus to the primary motor cortex
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35
Q

Where is the supplementary motor area located?

A
  • Longitudinal fissure but extends onto superior frontal cortex
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36
Q

What is the role of the supplementary area?

A
  • Bilateral stimulation

- Positional movements, fixation movements, body-wide attitudinal movements

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37
Q

Outline the pathway taken by the corticospinal tract

A
  • Leaves cortex and passes through internal capsule, downward through the brainstem
  • Forms the pyramids of the medulla
  • Majority of fibres decussate at the pyramidal decussation and descend in lateral corticospinal tract which terminate on interneurons of cord grey matter
  • Some fibres do not decussate but descend in anterior corticospinal tracts until thoracic region where they decussate and terminate on sensory relay neurons
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38
Q

What is the anterior corticospinal tract concerned with?

A
  • Bilateral postural movements

- By supplementary motor cortex

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39
Q

Fibres of the corticospinal tract originate from which cell type?

A
  • Betz cell, a giant pyramidal cell

- Found primarily in the primary motor cortex

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40
Q

What is the role of the corticobulbar tract and how are its fibres activated?

A
  • Activate motor cranial nerve nuclei
  • Mainly those of the face, jaw and tongue
  • Activated by corticospinal tract
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41
Q

Where is the red nucleus located?

A
  • Mesencephalon
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42
Q

Where does the red nucleus receive fibres from?

A
  • Directly from corticorubral tract through the mesencephalon
  • Indirectly from branching fibres from the corticospinal tract
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43
Q

Which tract arises from the red nucleus? Outline its course

A
  • Rubrospinal tract
  • Decussates in the lower brainstem
  • Follows the same course as corticospinal tract to terminate on interneurons or anterior motor neurons
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44
Q

Identify three incoming fibre pathways to the motor cortex

A
  • Somatosensory cortex
  • Frontal cortex anterior to motor cortex
  • Visual and auditory cortices
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45
Q

What is the tectospinal tract?

A
  • Crossed descending pathway
  • From tectum to anterior grey horn at cervical and upper thoracic regions
  • Orientation of head in response to visual (superior colliculus) and auditory (inferior colliculus) stimulation
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46
Q

What is the vestibulospinal tract?

A
  • Uncrossed descending pathway
  • From vestibular nucleus to appropriate antigravity muscles when the head is tilted to one side
  • To keep centre of gravity between the feet.
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47
Q

What is the raphespinal tract?

A
  • Descending pathway within tract of Lissauer
  • From raphe nucleus in medulla oblongata
  • Modulates sensory transmission between first and second order neurons in the posterior grey horn, particularly with respect to pain
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48
Q

What is pronator drift?

A
  • With arms outstretched and eyes closed
  • Affected limb drifts downwards and medially
  • Forearms pronate
  • Fingers flex
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49
Q

What are hemiplegia and hemiparesis?

A
  • Hemiplegia: Paralysis of one half of the body

- Hemiparesis: Weakness of one half of the body

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50
Q

What is paraplegia and paraparesis?

A
  • Paraplegia: Paralysis of both lower limbs

- Paraparesis: Weakness of both lower limbs

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51
Q

What is tetraplegia and tetraparesis?

A
  • Tetraplegia: Paralysis of all four limbs

- Tetraparesis: Weakness of all four limbs

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52
Q

Identify five features of an upper motor neurone disease

A
  • Pronator drift
  • Weakness with characteristic distribution
  • Exaggerated tendon reflexes
  • Extensor plantar response
  • Changes in tone: flaccid-spastic
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53
Q

Identity five features of a lower motor neurone disease

A
  • Hypotonia
  • Reflex loss
  • Weakness
  • Wasting
  • Fasciculation
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54
Q

Define stroke

A
  • A syndrome of rapid onset cerebral deficit (usually focal)
  • Lasting over 24 hours or leading to death
  • With no apparent cause other than a vascular one
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55
Q

Define transient ischaemic attack

A
  • A brief episode of neurological dysfunction

- Due to temporary focal cerebral or retinal ischaemia without infarction

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56
Q

Outline the epidemiology of strokes

A
  • Third most common cause of death
  • Higher in Asian and black African populations
  • Increases with age
  • Death rate folllwing a stroke is 25 per cent
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57
Q

Outline 10 risk factors for stroke

A
  • Hypertension
  • Smoking
  • Sedentary lifestyle
  • Alchohol
  • High cholesterol
  • Atrial fibrillation
  • Obesity
  • Diabetes
  • Carotid stenosis
  • Sleep apnoea
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58
Q

Identify the two types of stroke

A
  • Ischaemic stroke caused by thrombosis, stenosis, embolism, hypo-perfusion, 80% of strokes
  • Haemorrhagic stroke, caused by intracerebral haemorrhage or subarachnoid haemorrhage, 20% of strokes
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59
Q

What is the main cause of a TIA

A
  • Microemboli
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60
Q

What is amaurosis fugax?

A
  • Transient loss of vision in one eye

- Due to passage of emboli through the retinal arteries

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61
Q

Outline the clinical features of a TIA originating from the anterior circulation

A
  • Amaurosis fugax
  • Aphasia
  • Hemiparesis
  • Hemisensory loss
  • Hemianopic visual loss
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62
Q

Outline the clinical features of a TIA originating from the anterior circulation

A
  • Diplopia, vertigo, vomiting
  • Choking, dysarthria
  • Ataxia
  • Hemisensory loss
  • Bilateral visual loss
  • Tetraparesis
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63
Q

Which scoring system can be used to assess the severity of a TIA?

A
  • ABCD2
  • A: Age, 1 point if over 60
  • B: BP, 1 point if over 140/90
  • C: Clinical features, 2 points if hemiparesis, 1 point for aphasia
  • D: Duration of symptoms, 2 points if longer than one hour, 1 point if between 10 minutes and 1 hour
  • D: 1 point if diabetes
  • Admit if a score greater than 4
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64
Q

Once admitted following a score >4 on the ABCD2 scoring system, outline 3 investigations that should be carried out

A
  • Routine bloods (ESR, polycythaemia, vasculitis, thrombophilia)
  • CXR
  • ECG
  • Carotid Doppler
  • MR Angiography
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65
Q

Outline the pathophysiology of cerebral infarction

A
  • Reduced blood flow so less oxygen hence ATP
  • H+ is produced by anaerobic metabolism of available glucose
  • Ionic pumps fail, allowing calcium entry and glutamate release
  • Activation of destructive enzymes, destruction of organelles and fatty acid release for pro-coagulation
  • Leading to inflammatory damage, necrosis, apoptosis
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66
Q

What is the most likely cause of a cerebral infarction?

A
  • Infarction in internal capsule

- Following thromboembolism in middle cerebral artery

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67
Q

Outline the clinical features of a cerebral infarction

A
  • Contralateral limb weakness
  • Contralateral hemilegia
  • Aphasia
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68
Q

What is Wallenberg’s syndrome

A
  • Brainstem infarction

- Presenting as acute vertigo with cerebellar signs

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69
Q

A brainstem infarction of which area would produce a coma?

A
  • Reticular activating system
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70
Q

The locked-in syndrome is caused by infarction of which region of the brainstem

A
  • Upper brainstem
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71
Q

Pseudobulbar palsy is caused by infarction of which region of the brainstem?

A
  • Lower brainstem
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72
Q

Hemiparesis or tetraparesis is caused by infarction of which region of the brainstem?

A
  • Corticospinal tracts
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73
Q

Sensory loss is caused by infarction of which region of the brainstem?

A
  • DCML tracts

- Spinothalamic tracts

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74
Q

Facial numbness is caused by infarction of which region of the brainstem?

A
  • Trigeminal nuclei
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75
Q

Facial weakness is caused by infarction of which region of the brainstem?

A
  • Facial nerve
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76
Q

Dysphagia and dysarthria are caused by infarction of which region of the brainstem?

A
  • Glossopharyngeal nuclei

- Vagus nuclei

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77
Q

Diplopia is caused by infarction of which region of the brainstem?

A
  • Oculomotor nuclei
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78
Q

What is a lacunar infarct and which risk factor is it associated with?

A
  • Small infarcts seen on MRI, often symptomless

- Hypertension

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79
Q

What causes hypertensive encephalopathy and what are the symptoms?

A
  • Cerebral oedema

- Causing headaches, nausea and vomiting

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80
Q

What is Weber’s syndrome and what is its cause?

A
  • Ipsilateral oculomotor nerve plasy
  • With contralateral hemiplegia
  • Due to unilateral infarct in the midbrain
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81
Q

Identify neurological deficits associated with problems in the middle cerebral artery

A
  • Unilateral weakness involving face and arm, then legs
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82
Q

Identify neurological deficits associated with problems in the lateral medulla

A
  • Ipsilateral Horner’s syndrome
  • Vagus nerve plasy
  • Facial sensory loss
  • Contralateral spinothalamic sensory loss
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83
Q

Identify neurological deficits associated with problems in the posterior cerebral artery

A
  • Homonymous hemianopia

- Due to parietal and or temporal lobe

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84
Q

Identify neurological deficits associated with problems in the internal capsule

A
  • Motor or sensory loss

- Dysarthria from involvement of corticobulbar fibres

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85
Q

Identify neurological deficits associated with carotid artery dissection

A
  • Ipsilateral Horner’s syndrome from compression of sympathetic plexus
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86
Q

What is FAST?

A
  • Used by public and paramedics to make diagnosis of stroke and history based on simple history and examination
  • Face: Sudden weakness of face
  • Arm: Sudden weakness of one or both arms
  • Speech: Difficulty speaking, slurred speech
  • Time: Importance of rapid treatment
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87
Q

Identify the main treatment in cerebral infarction and one contraindication to its use

A
  • Thrombolysis e.g. altelapse

- Intracranial haemorrhage, head trauma within last 3 months

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88
Q

What is an alternative treatment to thrombolysis?

A
  • Aspirin 300 mg
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89
Q

Identify a surgical treatment used in cerbral infarction

A
  • Decompressive hemicraniectomy

- Reduced intracranial pressure in a middle cerebral artery infarct

90
Q

Identify two advantages and adisadvantage of using a CT in acute stroke?

A
  • Detects haemorrhage, more widely available

- Does not detect infarction

91
Q

Identify an advantage of using MRI over a CT acute stroke?

A
  • Detects infarction
92
Q

What is the role of MRI or CT with angiography?

A
  • Detects arterial stenosis in internal carotid artery
93
Q

What is the role of carotid doppler / duplex scanning with angiography?

A
  • Detects arterial stenosis in carotid and vertebral artery
94
Q

Outline six features of long-term management of stroke

A
  • Risk factors identified and addressed
  • Long term aspirin (75 mg)
    and clopidogrel following infarction
  • Internal carotid endarterectomy (removal of atheromatous intima from underlying media)
  • Physiotherapy
  • Speech and language therapy
  • Occupational therapy
95
Q

Outline the DVLA guidance following a stroke

A
  • Patients must stop driving for at least one month following a stroke
  • Patients must stop driving for a minimum of three months without recurrence of a TIA
  • Doctor must be happy that patient is safe to return to driving
96
Q

Outline the prognosis of a stroke

A
  • 25% die within 2 years, 10% die within first month
  • Mortality is higher following a haemorrhage than an infarction
  • Poor prognostic features include coma, defect in gaze, hemiplegia
97
Q

Identify three types of intracranial haemorrhage

A
  • Intracerebral / cerebellar haemorrhage
  • Subarachnoid haemorrhage
  • Subdural / extradural haemorrhage / haematoma
98
Q

What is a Charcot-Bouchard aneurysm?

A
  • Cause of intracerebral haemorrhage
  • Rupture of micro-aneurysms
  • Degeneration of small deep penetrating arteries
99
Q

Identify the clinical features of a cerebellar haemorrhage

A
  • Stupor/coma
  • Nystagmus / ocular palsies
  • Gaze deviates towards the haemorrhage and skew deviation may develop
100
Q

Identify four causes of subarachnoid haemorrhage

A
  • Saccular / berry aneurysm
  • AVM Malformation
  • Marfan’s Syndrome
  • Autosomal dominant polycystic kidney disease
101
Q

Identify a complication of a subarachnoid haemorrhage

A
  • Hydrocephalus
102
Q

Where do saccular aneurysms taken place?

A
  • Arterial junctions e.g. between PCA and ICA, between ACA and ACA
103
Q

What is an arteriovenous maformation

A
  • Tangle of blood vessels (cavernomas) in which oxygenated arterial blood is shunted into veins
  • Resulting in poor oxygenation
104
Q

Outline the clinical features of a SAH

A
  • Occipital headache
  • Followed by coma and death
  • Survivors experience neck stiffness and a positive Kernig’s sign
105
Q

Outline the investigations carried out if an SAH is suspected

A
  • CT imaging
  • Lumbar puncture shows xanthochromic CSF
  • Spectrophotometry - bilirubin in CSF
106
Q

Outline the treatment of an SAH

A
  • Placement of coils via a catheter in the aneurysm sac to promote thrombosis and ablation of the aneurysm
  • Hypertension should be controlled e.g. calcium channel blocker such as nimopidine
  • Bed rest and support
107
Q

Identify five causes of an intracranial venous thrombosis

A
  • Contraceptives
  • Pregnancy
  • Dehydration
  • Head inhury
  • Paranasal sinus infection
108
Q

Identify the two main locations of an intracranial venous thrombosis

A
  • Cortex, resulting in headache, hemiparesis, epilepsy, fever
  • Dural venous sinuses, resulting in ocular pain, fever, proptosis, chemises
109
Q

Outline the investigations used if a intracranial venous thrombosis is suspected

A
  • MRI which shows occluded sinuses and veins
110
Q

Outline the treatments of an intracranial venous thrombosis

A
  • Heparin initially

- Followed by warfarin for 6 months

111
Q

Identify the two main components of neurovascular repair following a stroke

A
  • Angiogenesis

- Neurogenesis

112
Q

Identify three trophic factors secreted by cerebral endothelium that communicate with neural precursor cells

A
  • MAtrix metalloproteinases
  • Vascular Endothelial Growth Factor
  • HMGB1
113
Q

What is neuroplasticity?

A
  • Brains ability to modify is structure and function

- In response to stimulation or injury

114
Q

Outline the mechanisms involved in neuroplasticity

A
  • Generation of new neurons

- Remodelling of synaptic connections

115
Q

What is positive memory?

A
  • Storage of important information

- Results from facilitation of synaptic pathways (sensitisation)

116
Q

What is negative memory?

A
  • Ignoring of information that is of no importance

- Results from inhibiting synaptic pathways (habituation)

117
Q

Outline the long-term potentiation model of memory

A
  • High frequency action potentials lead to release of glutamate
  • Entrance of Na+ at AMPa receptor which depolarises cell
  • Removal of Mg2+ and entry of Ca2+ at NDMA receptor which increases presynaptic glutamate synthesis and release
  • Long lasting increase in glutamate receptors and sensitivity
118
Q

What is the difference between short-term and long-term memory?

A
  • Short term refers to that which is held briefly in the mind
  • Long term is that which is stored and is capable of retrieval at the appropriate moments
119
Q

Identify the two types of long-term memory

A
  • Explicit: Recollections of facts and events that can be explicitly stated
  • Implicit: Performance of learned motor procedures such as riding a bike
120
Q

What is working memory?

A
  • Retrieval of items from long-term memory for a task at hand such as driving a car among a familiar route while making decisions based on past experiences
121
Q

What is consolidation?

A
  • Storage of new information in long-term memory

- Sensory information is relayed from sensory association areas to hippocampal complex for encoding

122
Q

Where does short-term declarative memory occur?

A
  • Hippocampus and other limbic system structures
123
Q

Where does long-term declarative memory occur?

A
  • Association areas of the cortex
124
Q

Where does short term implicit memory occur?

A
  • Widely distributed
125
Q

Where does long term implicit memory occur?

A
  • Basal ganglia
  • Cerebellum
  • Sensorimotor cortex
126
Q

What is retrograde amnesia?

A
  • Loss of ability to access previous memories

- Damage to thalamus which helps search the memory storehouse to find memories

127
Q

What is anterograde amnesia?

A
  • Loss of ability to create new memories

- Damage to hippocampus which determines what information is useful to remember and what isn’t

128
Q

Which region of the brain is associated with fear?

A
  • Amygdala
129
Q

Which region of the amygdala do the sensory association areas have access to?

A
  • Lateral nucleus of the amygdlaa
130
Q

Which region of the amygdala send signals to the hypothalamus to generate a stress response?

A
  • Bed nucleus

- Stria terminalis

131
Q

What hormone does the hypothalamus secrete as part of the stress response? From which nucleus of the hypothalamus does this occur?

A
  • Corticotrophin releasing factor from paraventricular nucleus
  • Carried to pituitary
132
Q

What is the endocrine target of CRF?

A
  • Anterior pituitary gland

- Which releases ACTH in response to CRF

133
Q

What is the endocrine target of ACTH?

A
  • Adrenocortical cells

- Which produces cortisol via a CAMP second messenger system

134
Q

Identify two stimuli that can enhance secretion of cortisol

A
  • Pain stimuli such as physical stress transmitted through spinothalamic tract
  • Mental stress from amygdala from sensory association areas and areas involved in memory
135
Q

Identify the benefit of cortisol release in stressful situations

A
  • Mobilisation of amino acids and fats from cellular stores
  • To be used in synthesis of glucose
  • As part of a fight or flight response
136
Q

Outline the negative feedback effects of cortisol

A
  • Effects on hypothalamus to decrease formation of CRF
  • Effects on anterior pituitary to to decrease formation of ACTH
  • To help regulate plasma concentration of cortisol
137
Q

What is generalised anxiety disorder (GAD)?

A
  • Ongoing state of excessive anxiety lacking any clear reason or focus
138
Q

Outline the epidemiology of GAD

A
  • 5% of people

- More common in women

139
Q

Outline the clinical features of GAD

A
  • Psychological symptoms include apprehension, fear, irritability, concentration difficulties and distractibility
  • Physical symptoms include crushing chest pain, palpitations, diarrhoea, sleep disturbance
  • On presentation patient looks worried, has a tense posture, restless behaviour, pale and sweaty skin
140
Q

Outline five other types of anxiety

A
  • Mixed anxiety and depressive disorder, with equal elements of both
  • Panic disorder, with severe physical symptoms of hyperventilation, tremor, sweating
  • Phobias, with a fear response to a stimulus of no particular concern e.g. agoraphobia fear of leaving home
  • PTSD, with anxiety triggered by past stressful experience
  • OCD, with compulsive, ritualistic behaviour driven by irrational anxiety
141
Q

Identify relaxation techniques for mild anxiety

A
  • Meditation
  • Yoga
  • The aim is to slow breathing, and produce muscle relaxation and mental imagery
142
Q

Identify the two stages of anxiety management

A
  • Cues and imagery to arouse anxiety

- Training to reduce this anxiety by relaxation, distraction and reassuring self-statements

143
Q

What is biofeedback?

A
  • Highlighting to patient a physiological measure that is abnormal in anxiety e.g. heart rate, EMG
  • To show patients that they are not relaxed even if they fail to recognise this
144
Q

Identify a therapy for phobia

A
  • Systematic desensitisation
  • Patient is exposed to a hierarchy of worsening fears
  • They practice exposure to each fear and work their way up the hierarchy
145
Q

Outline the application of CBT to anxiety

A
  • Identification of mental cues that provoke exacerbations

- Alteration of the patients schema (the way they loo at themselves, the future and their situation) that feeds anxiety

146
Q

What is GABA?

A
  • Gamma-aminobutyric acid

- Main inhibitory neurotransmitter in the brain

147
Q

Identify the two types of GABA receptors

A
  • GABAa (ligand gated ion channel)

- GABAb (G-protein coupled receptor)

148
Q

Outline the mechanism of action of benzodiazepeines

A
  • Bind to an accessory site on GABAa receptor

- Opening of chloride channels and entrance of Cl- which hyperpolarises the cell

149
Q

Identify three example of benzodiazepines

A
  • Diazepam
  • Flurazepam
  • Clonazepam
150
Q

What is the dosage of diazepam

A
  • 2-15 mg daily

- Taken orally

151
Q

Outline four side effects of benzodiazepines

A
  • Sedation and memory problems
  • Dependence and tolerance
  • Withdrawal syndrome
  • Interaction with alcohol producing a hangover syndrome
152
Q

What are 5-HT1a receptors?

A
  • Auto-inhibitory receptors
  • Located on 5-HT neurons in the raphe nuclei of the reticular formation
  • Which limit firing of these cells
153
Q

Identify three examples of SSRIs

A
  • Fluoxetine
  • Paroxetine
  • Sertraline
154
Q

Outline the dosage of SSRIs

A
  • Orally 20 mg daily
  • Can be increased over a month
  • Maximum dose of 60 mg daily
155
Q

What is buspirone and what is it used to treat?

A
  • Partial 5-HT1a agonist

- Used to treat generalised anxiety disorder

156
Q

How do buspirone and SSRIs work?

A
  • Induce desensitisation of of somatodendritic 5-HT1A autoreceptors
  • Resulting in increased excitation of serotonergic neurons and enhanced 5-HT release
157
Q

What are the main side effects of SSRIs?

A
  • Nausea
  • Diarrhoea
  • Agitation
  • Insomnia
  • Anorgasmia
158
Q

What are the main side effects of buspirone?

A
  • Nausea
  • Headache
  • Restlessness
159
Q

Why are beta blockers used in the treatment of anxiety?

A
  • Inhibiting beta-adrenoreceptors on adrenal medulla and sympathetic nerves
  • To reduce physical symptoms such as sweating, tremor, tachycardia
160
Q

Identify an antipsychotic used in the treatment of anxiety

A
  • Olanzapine
161
Q

Identify three antiepileptics used in the treatment of anxiety

A
  • Gabapentin
  • Pregabalin
  • Valproate
162
Q

What type of synapse is involved between the Renshaw cell and alpha motor neuron

A
  • Glycinergic
163
Q

Where do aminergic pathways arise?

A
  • Specialised cell groups in pons and medulla

- E.g. raphe nucleus

164
Q

What are the main types of neurotransmitters are involved in aminergic pathways?

A
  • Noradrenaline

- Serotonin

165
Q

What are the two effects of aminergic pathways?

A
  • Inhibitory effects on sensory neurons

- Facilitatory effects on motor neurons

166
Q

Where do the corticobulbar tracts arise?

A
  • Central sulcus in precentral gyrus

- Superior to lateral fissure

167
Q

Which part of the internal capsule do the corticobulbar tracts descend through?

A
  • Genu
168
Q

Which cranial nerves are bilaterally innervated?

A
  • Oculomotor
  • Trochlear
  • Trigeminal
  • Abducens
  • Glossopharyngeal
  • Vagus
  • Accessory
169
Q

How is the hypoglossal nerve innervated?

A
  • Contralateral innervation
170
Q

How is the facial nerve innervated?

A
  • Superior part is bilaterally innervated

- Inferior part is contralaterally innervated

171
Q

What is a reperfusion injury?

A
  • Oxygen-dependent damage to ischaemic area when blood flow returns
  • Caused by release of of oxygen dependent free radicals
172
Q

Identify two causes of a reperfusion injury

A
  • Blood flow encounters tissue where calcium transport is impaired
  • Neutrophils and macrophages (inflammatory response)
173
Q

What is an ischaemic penumbra?

A
  • Swollen area of brain surrounding infarcted area
  • That does not function but is structurally intact
  • Which is detected on MRI
174
Q

Identify three treatments following a cerebral infarction

A
  • Thrombolysis (alteplase)
  • Aspirin 300 mg if thrombolysis is contraindicated
  • Decompressive hemicraniectomy if massive middle cerebral artery infarct
175
Q

When should heparin and warfarin be given following a stroke?

A
  • If there is atrial fibrillation
176
Q

Outline the mechanism of action of alteplase

A
  • Tissue plasminogen activator
  • Converts plasminogen to plasmin
  • Which is a proteolytic enzyme that digests fibrin fibres
  • Resulting in lysis of clot
177
Q

Identify a potential adverse effect of thrombolysis

A
  • Hypocoagulabiltiy of the blood
178
Q

Why is CT scanning important before administering thrombolysis?

A
  • To rule out haemorrhagic stroke
179
Q

Outline the mechanism of action of aspirin

A
  • Irreversibly inactivation of COX-1 and COX-2
  • Reduced thromboxane A2 production
  • Reduce platelet aggregation / thrombosis
180
Q

Identify three adverse effects of aspirin

A
  • GI effects e.g. nausea and vomiting
  • Post viral encephalitis (Reye’s syndrome)
  • Risk of bleeding if given with warfarin
181
Q

Outline the mechanism of action of clopidogrel

A
  • Irreversible inhibition of P2Y12 receptors on platelets

- Resulting in reduced platelet activation

182
Q

Identify two adverse effects of clopidogrel

A
  • Prodrug, metabolised by CYP2C19, those with a genetic variant where CYP2C19 is less activate have an increased risk of thrombosis
  • Higher mortality rates compared to ticagrelor
183
Q

Outline the mechanism of action of nimopidine

A
  • Calcium channel antagonist
  • At L-type calcium channel
  • Vasodilation of resistance vessels
184
Q

Outline three side effects of nimopidine

A
  • Ankle swelling
  • Flushing
  • Headaches
185
Q

What is flumazenil? Identify two uses of flumazenil

A
  • Inverse agonist at GABAA receptor
  • Reverse effects of benzodiazepine overdose
  • Reverse sedative effects of benzodiazepines in anaesthesia during surgical procedures
186
Q

What is meant by bias?

A
  • Conducting, analysing or reporting a study in a way that tends to lead to a particular conclusion
187
Q

Identify four examples of pre-trial bias

A
  • Selection bias
  • Definition bias
  • Bias in concepts
  • bias in concurrent disease
188
Q

What is meant by selection bias? How can it be reduced?

A
  • Errors in assignment or selection of patients for a study
  • Subjects studied are not representative of the target population
  • Or they differ from each other by factors that may affect the outcome of the study.
  • Random allocation
189
Q

What is meant by definition bias?

A
  • Study subject is not clearly defined resulting in ambiguity
190
Q

What is meant by bias in concepts?

A
  • Lack of clarity about the concept that are used in the research, resulting in subjective interpretation
191
Q

What is meant by bias in concurrent disease

A
  • Patients suffer from unrelated conditions which affect responses
192
Q

Identify five examples of bias during the trial

A
  • Information bias
  • Instruction bias
  • Lead-time bias
  • Attrition bias
  • Hawthorne effect
193
Q

What is meant by information bias? How can it be reduced?

A
  • Errors in measuring exposure or a disease

- Blinding

194
Q

Identify four types of information bias

A
  • Observer bias
  • Interviewer bias
  • Recall bias
  • Response bias
195
Q

What is meant by instruction bias

A
  • No clear instructions are prepared

- Investigators use discretion which varies from person to person

196
Q

What is meant by lead-time bias

A
  • Cases of disease are not detected at same stage of disease
197
Q

What is meant by attrition bias?

A
  • Cases of dropout which varies between groups
198
Q

What is meant by Hawthorne effect

A
  • Individual knows they are being investigated

- And their behaviour and responses alter in light of this

199
Q

Identify two examples of post-trial bias?

A
  • Confounding bias

- Statistical bias

200
Q

What is meant by confounding bias?

A
  • Outcome is affected by other factors other than the intervention e.g. smoking on a study on effect of alcohol on heart disease
201
Q

What is meant by statistical bias?

A
  • Use of inappropriate statistical tests
  • Or low statistical power
  • Leading to misleading conclusions
202
Q

Which test should be used when data is:

[A] Normally distributed

[B] Not normally distributed

A
  • T-test

- Mann-Whitney U test

203
Q

What is a continuous variable?

A
  • Numerical value that is measured on a continuous scale

- E.g. height in centimetres

204
Q

What is a binary variable?

A
  • Categorical value that is measured as one of two possible values
  • E.g. taller than a given height or not
205
Q

What is a dependent variable?

A
  • The variable that is being measured

- E.g. treatment outcome

206
Q

What is n independent variable?

A
  • The variable that is manipulated

- E.g. treatment used

207
Q

When is the unpaired T-test carried out?

A
  • Continuous DV
  • Discrete IV
  • Two comparable groups
  • Example: FEV in those with asthma compared to those without asthma
208
Q

When is the ANOVA test carried out?

A
  • Continuous DV
  • Discrete IV
  • More than two comparable groups
209
Q

When is linear regression carried out?

A
  • Continuous DV

- Groups are not comparable

210
Q

When is logistic regression used?

A
  • Binary DV

- Groups are not comparable

211
Q

When is Chi-Square test used?

A
  • Binary DV
  • Discrete IV
  • Groups are comparable
212
Q

What is sensory memory? Give two examples of sensory memory?

A
  • Physical features of a stimulus are stored for a very brief period of time
  • Iconic memory: sight
  • Echoic memory: sound
213
Q

What is the role of the the central executive?

A
  • Portion of working memory involved in cognitive tasks such as problem solving
214
Q

What is the role of phonological loop?

A
  • Storage of auditory information by repetitively rehearsing it
215
Q

What is the role of the visuo-spatial sketchpad?

A
  • Storage of visual and spatial information
216
Q

What is meant by episodic buffer? Which type of memory is it associated eith

A
  • Linking information across domains e..g visual, spatial and auditory, chronology
  • Semantic memory (context of memory of written and spoken words)
217
Q

According to the levels of processing model of memory, what is meant by maintenance rehearsal?

A
  • Repetition of verbal information simply by repeating it

- Maintained in short term memory

218
Q

According to the levels of processing model of memory, what is meant by elaborative rehearsal?

A
  • Thinking deeply about information

- To consolidate short term memory or maintain long term memory

219
Q

According to the levels of processing model of memory. what is meant by encoding specificity? Give three examples

A
  • Way in which we encode information affects our ability to retrieve it later
  • Mnemonics (method of loci)
  • Narrative stories
  • Smart drugs
220
Q

Outline four theories of forgetting

A
  • Superficial processing (link to maintenance rehearsal)
  • Decay of memory trace
  • Interference
  • Motivated forgetfulness

Semester 3: Mind and Movement (21 decks)

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