Deep Brain Stimulation

Front 1

What is deep brain stimulation?

Back 1

Application of a mild, adjustable,
reversible electrical current to target
sites of the brain
The overall objective is to modulate
neural networks within a particular brain
circuit

Front 2

What 3 conditions can be treated with DBS?

Back 2

PD

Dystonia

Essential tremor

Front 3

What is the epidemiology of PD?

Back 3

Parkinson’s disease is common, affecting about
0.5% of people aged 65 to 74 years
1–2% of people aged 75 years and older
1 in 20 patients are under the age of 50

Front 4

What are 4 cardinal motor signs in PD?

Back 4

1. Tremor at rest
2. Rigidity
3. Bradykinesia
4. Loss of postural
reflexes

Front 5

What is an essential tremor?

Back 5

Tremor of arms hands and fingers during voluntary movements e.g. eating.

Action tremor i.e. intensifies upon use of muscles i.e. distinct from resting tremor in PD

Front 6

There are 5 stages to DBS, the first is pre-implantation, what does this involve?

Back 6

Consider patient selection:
• Age
• Disease duration
• L-dopa responsiveness

Front 7

What does the 2nd stage of DBS involve?

Back 7

Implanting the leads:

Brain is mapped with neuroimaging techniques
(either MRI or CT scan) and the
implantation requires the use of stereotactic frames

Front 8

What does the 3rd stage of DBS involve?

Back 8

Intraoperative test stimulation
e.g. in PD the tremor or rigidity
and bradykinesia respond to
intraoperative stimulation

Front 9

What does the 4th/5th stage of DBS involve?

Back 9

4th = healing

5th = Programming sessions: Involves the use of a hand held machine that communicates wirelessly with the device in the chest
Programming variables that must be set are
pulse width, frequency, voltage and electrode
configuration.
Optimization of the settings is necessary for
the first few months to ensure the DBS
programming is personalised to the individual
patient

Front 10

What are the 3 main components to DBS?

Back 10

1. Lead - implanted specific parts of brain
2. Extension - runs from head, down side of neck, behind ear to IPG placed subcu below clavicle/abdo)
3. Implanted Pulse Generator (IPG) - battery powered neurostimulator which sends impulses to the brain

Front 11

What is the intended effect of DBS on the brain?

Back 11

Inhibition - treat symptoms via suppressing the normal oscillations in BG controlling motor output

OR

Excitation - activation outputs e.g. STN output efferent axons - change in discharge pattern + reduction in rate

Front 12

What do you give in early PD, no cardinal symptoms?

Back 12

Levodopa
Dopamine agonists
MAO-B inhibitor

Front 13

What do you give in patients with PD and motor/non-motor complications + unrelieved symptoms?

Back 13

Levodopa
Dopamine agonists
MAO-B inhibitors
Catechol-O-methyltransferase
(COMT) inhibitors
Role for apomorphine
and amantadine

Front 14

What do you give in patients with PD and advanced life limiting PD with significant
disability?

i.e. severe PD + medication side effects + lengthening off periods

Back 14

DBS

Patients should have no significant cognitive dysfunction
No active psychiatric symptoms
Both sporadic and familial PD patients are eligible for DBS

Front 15

What do studies show DBS has the ability to improve?

Back 15

• Tremor dyskinesia
• Ability to do everyday activities
• Less disability overall

Front 16

What are the risks in DBS?

Back 16

Infection (most common complication) up to 15%
Intracerebral haematoma (0-15%)
Death (0-4.4%)

Device failure - mechanical/electrical problems
electrode migration, lead erosion or fracture
Stimulation related complications; sensory disturbance, psychiatric disturbance, speech, visual and auditory disorders
Depression and suicidal behaviour

Front 17

How can DBS treat dystonia?

Back 17

Treat major debilitating symptom - involuntary muscle contractions -> abnormal convoluted/painful movements + postures

Electrodes implanted in GPi

Front 18

What types of dystonia can DBS treat?

Back 18

Primary generalised dystonia
DYT1 positive or negative dystonia
Hemidystonia

Front 19

What are further applications of DBS?

Back 19

1.Tourette’s syndrome
2.Major depressive disorder
3.Obsessive compulsive
disorder