Stage 1

Question 1

Structures of the Basal Ganglia

Answer 1

Striatum (Putamen, Caudate)
Globus Pallidus (GPi, GPe)
STN
SNr

Question 2

What is the target of cortical input to the Basal Ganglia?

Answer 2

Striatum (Caudate, Putamen)

Question 3

The source of output to the thalamus?

Answer 3

Globus Pallidus (GPi, GPe)

Question 4

Target location for GPi

Answer 4

Posteroventral

Sensorimotor portion directly superior to optic tract

Question 5

Target location for STN

Answer 5

Dorsolateral aspect

Question 6

What exams are used for indirect targeting?

Answer 6

T1 MRI

Question 7

What exams may be used for direct targeting?

Answer 7

T2 MRI

Question 8

Approximate STN coordinates

Answer 8

X: 11-15mm (12mm mean) lateral from MCP
Y: 2-3 mm posterior from MCP
Z: 3-4 mm ventral to ACPC line
Arc angle: 15 degrees Ring angle: 60 degrees

Question 9

Approximate Vim coordinates

Answer 9

X: 10.5-11.5 mm + 1/2 width of 3rd ventricle
Y: 25% of the ACPC length posterior to MCP
Z: 0 MCP plane
Arc: 15 degrees Ring: 60 degrees

Question 10

Approximate GPi coordinates

Answer 10

X: 18-23 mm lateral from MCP
Y: 2-3 mm anterior to MCP
Z: 2-4 mm ventral to MCP
Arc: 0-10 degrees Ring: 60 degrees

Question 11

Thalamic homunculus

Answer 11

Medial (face), central (arm tremor), to Lateral (feet)

Question 12

Ventriculography

Answer 12

X-ray

Contrast is injected into the CSF allowing visualization of the ventricles and ACPC

Question 13

CT Image observations

Answer 13

Bone is white, tissue is grey, fluid is dark

Question 14

Area of interest size for a T2 scan

Answer 14

28 to 32 cm

Question 15

The three guide tube lengths for A/O cannula

Answer 15

25mm (most common)
15mm
10mm

Question 16

Name lead length for A/O drive

Name lead length for Star drive

Answer 16

A/O = 237mm (length of micro electrode)
Star = 375mm

Question 17

Length of A/O MER tip

Answer 17

3mm (most common)

10mm

Question 18

Length of FHC MER tips

Answer 18

10mm most common

3mm

Question 19

Above target ranges for FHC cannula

Answer 19

40mm
20mm
To target

Question 20

The cannula and lead (A/O) and FHC move all together or separately in an array?

Answer 20

All together for A/O

FHC array moves together, single does not move

Question 21

Leksell

Right, Posterior, Superior= ?
Left, anterior, inferior = ?

Answer 21

Left, anterior, inferior = >100

Right, posterior, superior =

Question 22

Structures to avoid in all procedures

Answer 22

1. Sulci and blood vessels
2. Ventricles
3. Optic tract (close proximity, not pierced)

Question 23

Anatomy pierced when targeting STN

Answer 23

1. Cortex (gyrus)
2. Sub cortical white matter
3. Caudate (unless more lateral trajectory angle used)
4. Thalamus (usually VOP)
5. Zola incerta
6. STN
7. Subtanstia nigra

Question 24

Anatomy pierced when targeting VIM

Answer 24

1. Cortex (gyrus)
2. Us cortical white matter
3. Caudate (unless a more lateral trajectory used)
4. Dorsal thalamus
5. Ventral thalamus: vim nucleus- target
6. Ventral thalamus: VC nucleus (dbs electrode not placed here but blunt tip could be)
7. Zona incerta (possibly with tip)

Question 25

Anatomy pierced when targeting GPi

Answer 25

1. Cortex (gyrus) 2. Sub cortical white matter 3. Putamen 4. Globus pallidus externus 5. Globus pallidus internus (target)

Question 26

What are the imaging protocols for CT and MRI?

Answer 26

CT- no gaps contiguous, full field of view - whole head, no gantry tilt, 3mm slices, MRI - 3mm slices or less, T2 field of view is slab 28-32cm, no oblique slices, contiguous no gaps, square matrix

Question 27

When should gadolinium be used?

Answer 27

Run T2, then inject gad run T1 right away, to increase visibility of vascular structures

Question 28

STN bordered by what?

Answer 28

``` ZI - superior IC - lateral & anterior Red nucleus - posteromedial Medial lemniscus - posterior CN 3 - medial / ventralmedial Autonomic pathways - very anteromedial SNr- inferior/ventral ```

Question 29

CRW distances, center, positive negative directions

Answer 29

160 mm distance to top of tool carrier Coordinates to center = 0/0/0 Superior, anterior, right = positive (+) Left, inferior, posterior = negative (-)

Question 30

Frames are accurate w/in what margin?

Answer 30

2mm

Question 31

Average AC-PC length is

Answer 31

22-26, 24 avg

Question 32

FHC microdrive

Answer 32

Target is 30mm and top of dbs holder to end of measuring tool is 375MM

Question 33

Leksell frame with A/O drive

Answer 33

Tool holder must be set to positive 30mm

Question 34

Lead lengths

Answer 34

``` 3387 = 10.5 3389 = 7.5 (These are from base of contact 0) 3387 = 12 3389 = 9 (From distal tip of lead to top of contact 3) ```

Question 35

Examples of gray matter

Answer 35

STN, SNR, GPi, thalamus, putamen, | Grey because they're unmylenated neurons

Question 36

SAR

Answer 36

0.1 w kilo

Question 37

MER Tremor cell Kinesthetic cell

Answer 37

Tremor cell - Synchronized with patients tremor | Kinesthetic cell - You will hear it fire with active or passive firing of the joint

Question 38

If you hit a little thalamus, where could you be?

Answer 38

Anterior, Posterior

Question 39

Name examples of white matter

Answer 39

Internal capsule Zona incerta AC/PC Optic tract, corpus collusom White because mylenated nerve cells,

Question 40

Arc/ring typical ranges on the stealth

Answer 40

Arc 13.5-24 degrees | Ring 55-65 degrees

Question 41

Default trajectories for ring and arc angle

Answer 41

15 arc degrees parasagittal | 60 degrees from axial

Question 42

How do I tell I'm holding CRW correctly?

Answer 42

Two eyeballs, written on the frame

Question 43

For leksell do what for sterile

Answer 43

Avg y and z

Question 44

Here is a scenario, from i.e. Wrong what do you do?

Answer 44

You can ID the problem, cannot solve the problem. Surgeon or rep of the manufacturer must solve it

Question 45

Motor thalamus

Answer 45

Pallidus receiving = VOP/VOA Cerebellar = VIM motor Lemniscal = sensory VC