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Flashcards in Functional Deck (106):
1

What is the most common type of tremor?

Essential tremor

2

What types of tremor do you know?

PD
ET
Cerebellar
Rubral
Cortical
Orthostatic
Palatal

3

What are the features of ET?

Mostly upper limb
Head 30% and voice 5% involvement
Symptomatic tremor in the lower limbs is rare
No tremor at rest / during sleep
Dominant inheritence

4

What are the medical treatments for ET?

Beta blcokers
Benzodiazepines
CAO inhibitors
**Tremor is suppressed with alcohol

5

What are the features of PD?

Tremor
Rigidity
Bradykinesia
Postural instability

6

What medication types are used for PD?

Levodopa
Dopa agonists - ropinirole
Anticholinergics - amantadine / trihexyphenidyl
COMT inhibitors
MAO-B - selegiline

7

What are the main side-effects of levodopa?

Dyskinesias - usually develop >5 years after starting levodopa

8

How can dystonias be classified?

Primary
Secondary
Hereditary
Sporadic

9

What causes hemiballismus?

Destruction of the STN

10

What are the targets for ET?

VIM

11

What is the target for tourettes?

CM / PF bilaterally

12

Where should stimulation of the GPi be for PD?

Dorsal and inferior above the optic tract

13

What is the best target for ET tremor?

VIM

14

What is the best target for dyskinesias / dystonia?

GPi

15

What is the target for PD?

STN or GPi

16

How do you calculate the laterality of stimulation site?

Width of the third ventricle

17

Why is DBS better than lesioning (thalamotomy)?

Safety of bilateral interventions as bilateral lesioning results in severe side effects (loss of corticobulbar function 25% with bilateral thalamotomy)

18

What are the benefits of DBS over lesioning?

Testable
Adjustable
Reversible
Non-destructive
Safe bilaterally

19

What sensory phenomena do you get with VIM stimulation?

Thumb and angle of mouth with high voltage stimulation

20

What is the outcome of DBS for MS?

Poorer results with demyelinating causes

21

How long is the onset of effect with SRS for thalamotomy?

Between 6 weeks and 6 months

22

Which target for PD has more cognitive issues?

STN! So if patient has pre-existing cognitive issues then target GPi

23

What is the benefit of STN over GPi?

STN DBS has lower medication requirement so have less dyskinesias

24

When is GPe targeted?

Tourettes

25

What are the differences between GPi and STN stimulation for PD?

Overall outcomes are the same but off time and on time with dyskinesia is less with STN; GPi is better for those with baseline mild cognitive dysfunction;

26

Where is the target for cluster headache DBS?

Ipsilateral hypothalamus

27

How do you assess severity of Parkinson's disease?

UPDRS

28

What is the DBS target for epilepsy?

Anteriomedial thalamic nucleus causes 50% reduction in seizure frequency

29

What are the inputs to the anteromedial thalamic nucleus?

Medial mammillary bodies, reticular nucleus, entorhinal cortex, subiculum and anterior cingulate

30

What are the outputs of the anteriomedial thalamic nucleus?

To the frontal cortex and hippocampus so stimulation of the anteromedial thalamic nucleus reduces seizures!

31

What is the target for occipital neuralgia ganglionectomy?

C2 and 3 ganglionectomy;
Unilateral for unilateral pain and bilateral for bilateral pain;

32

What is the complication of sympathectomy?

Systemic hyperhydrosis

33

What is the main indication for DREZ lesioning?

Root avulsion, (post-herpetic neuralgia and post-amputation pain)

34

Does DREZ or myelotomy help phantom limb sensation?

No (but may help for pain if this is due to root avulsion)

35

How is cordotomy usually performed?

Percutaneous under CT guidance; The spinothalamic tract is identified by stimulation;

36

When is cordotomy performed?

For severe cancer pain;
Pain relief for roughly 6 months;

37

Algorithm for trigeminal neuralgia

Slavin et al 2007 head and face medicine

38

What are the neurosurgical options for spasticity

Medical - NMJ blockers / Benzodiazepine / Gaba agonists / Tizanidine
Surgery - Intrathecal baclofen / dorsal rhizotomy etc / Peripheral neurotomy / Tendinotomy / rhizotomy

Sindou 2007 algorithm - look it up!

39

What is the definition of spasticity?

Movement velocity dependent increase in muscle tone
(unlike with rigidity which is movement velocity independent)

40

What is the function of baclofen?

Gaba B agonist

41

What are the methods of performing functional surgery?

Destruction - chemical / thermal / radiation
Modulation - electrical / chemical / genetic

42

What are the features of Sudek atrophy?

Reflex sympathetic dystrophy:

43

What are the types of Chronic regional pain syndrome?

Type 1: ...

44

What is the management chronic regional pain syndrome?

Thermography to make diagnosis
Vascular testing to ensure no ischaemia of the limb
Physical therapy
Anticonvulsants / antidepressants
Sympathetic blocks - some do not respond to this
Psychological testing
Surgery - Spinal Cord Stimulators

45

How do you perform spinal cord stimulation?

Percutaneous insertion into the epidural space
Stimulation trial with electrodes tunnelled to a subcutaneous pocket
Permanent implantation if successful or removal if unsuccessful

46

What do you do if your pocket with the spinal cord stimulator has pus discharge?

Remove the implanted device, washout the pus!!
Send pus for MC&S
Start abx
New system once everything heals

47

Why dont you use radiofrequency for 1st branch trigeminal neuralgia?

To prevent corneal keratitis
(so for V1 TN use balloon to get partial numbness until the patient looses sharp and dull discrimination)

48

Why don't you want complete numbness with percutaneous TN treatment?

So the patient does not get anaesthesia dolorosa

49

How do you perform TN thermal ablation?

70 deg C for up to 60-90 seconds

50

Where is the balloon for treatment in Meckel's cave?

The needle is outside foramen ovale and the balloon is inserted into Meckel's cave

51

What is the difference between typical and atypical neuralgia?

**Typical trigeminal neuralgia does not have sensory loss**

52

What would you do if the TN is due to a large basilar artery?

Try and place teflon
If not successful then percutaneous treatments or open rhizotomy can be performed

53

How do you control bleeding from Dandy's vein (petrosal vein) in TN?

Gelfoam and wait

54

Where is the lesion made with a DREZ?

Layers 1-5 of the dorsal root

55

Where do you make the incision in a DREZ?

Dorso-lateral sulcus (lateral to the dorsal root entry zone)

56

What is a cordotomy?

Interruption of the lateral spinothalamic tract

57

When is a cordotomy performed?

Mainly for cancer pain to a limb

58

Which areas of the brain are associated with an acute pain stimulus?

Insula and anterior cingulate cortex (likely emotional response to pain)

59

How many DA neurons are in the substantia nigra?

500,000

60

How many DA neurons do you lose when you develop PD?

50%

61

What are the features of PD?

(TRAP)
Tremor
Rigidity
Akinesia / Bradykinesia
Postural / gait abnormalities

62

What are the targets for PD?

STN > GPi > Thalamus > PPN

63

What is the main target for essential tremor?

Vim

64

What is the main target for dystonia?

GPi

65

What proportion of the population have PD?

3% over the age of 65 y

66

What proportion of PD patients are good candidates for DBS?

25%

67

Is ET more common than PD?

ET 10x more common than PD

68

What is the somatotopy of the Vim?

Head near the 3rd ventricle and feet near the posterior limb of the IC

69

What is the problem with chronic leva dopa use in PD?

Less effect of drugs
Unpredictable drug response
On/Off
Dyskinesia

70

What are the risk of DBS?

Bleeding
Infection
Hardware failure / migrationI

71

What structure if STN DBS too anterior?

Corticospinal tracts cause Motor signs

72

What structure if STN DBS too medial?

3rd nerve causing eye deviation

73

What structure if STN DBS too posterior?

medial lemnisus causing paraesthesia symptoms

74

What are the main complications with doing STN DBS in patients >70 years?

Dementia / Depression

75

What other ways are there of making a lesion in the brain?

SRS
ExAblate (focused ultrasound)

76

How does focused ultrasound work?

MR thermography used to measure the temperature during short burst (13 secs) of high frequency USS. Keep making the lesion bigger until the tremor goes.

77

What is the problem with bilateral thalamotomy?

Speech impairment (so only done unilaterally and put a DBS on the other side)

78

If a patient has STN DBS and then develops gait problems. What do you do?

Do PPN in addition to the STN

79

What is deafferentiation patient?

Loss of sensory input resulting in pain

80

What are ablative pain procedures in the spine?

Cordotomy
Myelotomy
DREZ
Ganglionectomy
Dorsal rhizotomy

81

When are lesions made in the hypothalamus for pain?

Breast cancer pain (look this up)

82

What are thalamus DBS targets for pain?

Only 20% improvement:
VPL/M
PVG/PAG
IC

83

What are the indication for spinal cord stimulation?

Failed back syndrome
Refractory angina
Peripheral Vascular Disease
CRPS type 1

84

What are type 1 and 2 TN?

TN1 = sudden onset brief severe unilateral pain
TN2 = on-going background pain

85

Treatments for TN?

Drugs - Carbamazepine
Ablation - Injection (glycerol), avulsion, gasserian neurectomy, radiofrequency ablation, SRD
Non-ablative - balloon compression / neurovascular decompression

86

What medications are given with deafferentation pain?

Gabapentin
TCAs
(do not do ablative procedures!)

87

What are the treatments for spasticity?

Baclofen infusion
Selective rhizotomy (for spastic paraplegia)

88

How do you do a selective rhizotomy?

Under EMG you stimulate the rootlets. Those that are most involved with inducing most contraction / spasticity you cut!

89

How do myelotomies work?

Cutting the midline fibres to prevent the reflex arc

90

How do you grade spasticity?

Ashworth scale (0-4)
0 = no increase in muscle tone
4 = held rigid in flexion or extension

91

What type of pain is best for deafferenation pain?

Spinal cord stimulation

92

What type of pain is best for somatic type / cancer pain?

Ablations e.g. DREZ if one level / cordotomy if multilevel

93

What is damaged in post-herpatic neuralgia?

Dorsal root ganglion - reorganisation of input to different rexed lamina

94

What is a dorsal rhizotomy?

Where the nerve is cut between the DREZ and the dorsal root ganglion

95

What is the best treatment for post herpatic neuralgia?

For allodynia (sharp tactile pain) do dorsal rhizotomy of the affected levels
For burning pain will not help!

96

When do you do DREZ vs cordotomy?

DREZ for localised levels whilst cordotomy for whole limbs

97

What medications can be used to reduce leva dopa induced dyskinesias?

Reduce the dose of L-dopa by spreading the dosing, adding in Dopa agonists (ropinirole / pramipexole), COMT inhibitors and amantadine

98

What are the side effects of DA agonists.

Impulse control dysfunction

99

What is the trigeminal depressor response?

Bradykinesia on entering the needle into the ganglion

100

How do you know when the needle enters the foramen ovale?

Induce contraction of masseter

101

Which trigeminal neuralgia procedure can be done under LA?

Thermocoagulation (glycerol and balloon compression is under GA)

102

What are the outcomes of thermocoagulation?

90% instant improvement but pain recurs after 18 months (but anaesthesia dolorosa is more common!)

103

What are the complications associated with percutaneous treatments of TN?

Wrong division e.g. V1 damage - corneal numbness
Carotid artery injury
Temporal lobe injury
Herpes reactivation

104

Which percutaneous procedure for TN has the highest pain recurrence?

Glycerol

105

How many Gy is given to the CN5 for TN?

80 Gy

106

How long does gamma knife take to work in TN?

Max effect at 2 years. Starts to work at 2 months.