DBS is a surgical procedure in which electrodes are implanted into selected areas in the brain to regulate activity of various structures

1. DEEP BRAIN STIMULATION
By, Dr.Y Guru Prasad
N III unit

2. DBS
⚫DBS is a surgical procedure in which electrodes are
implanted into selected areas inthe brain to regulate
activity of various structures.
⚫The procedure is potentially reversible, usually with
minimal damage to any brain tissue.

3. DBS
⚫In his text “Compositiones
medicamentorum” (46 AD),
Scribonius Largo, head
physician of the Roman
emperor Claudius, first
suggested using pulses of
electricity using sting rays
to treat afflictions of the
mind.

4. DBS-history
⚫Alim Benabid- discovered
that electrical stimulation of
the basal ganglia improved
symptoms of Parkinson's
disease in the late 1980s .
⚫The development of modern
deep brain stimulation
(DBS) is widely attributed to
him
⚫(Sep 1,2018,Lancet)

5. Uses of DBS
⚫Essential tremor (ET) – FDA in 1997
⚫Parkinson disease (PD)-FDA in 2002
⚫Generalised Dystonia or Tourette syndrome,
⚫As well as a variety of disorders such as Chronic pain,
depression, and obsessive compulsive disorder
(OCD),Cluster headaches,spasticity,addiction

6. Stimulation sites:
⚫VIM thalamus(ventral intermediate nucleus)
⚫Gpi-Globus pallidus interna
⚫STN-Subthalamic nuclei
⚫Caudal Zona increta (ZI*)and PPN
⚫Other subcortical and even cortical areas..
*The ZI, an embryological derivative of the ventral thalamus,
is a distinct heterogeneous nucleus that lies at the base of
the dorsal thalamus-role in PD.

7. Target and effects:-
• Tremor-ET,PD,MS-VIM✔
• Dystonia/ballism/myoclonus-VIM✔
• Tics-Centromedian parafascicular
complex✔
• Tourette
Thalamus
• Dyskinesia(LD induced,tardive)✔
• Dystonia✔
• Tics(Tourette syndrome)✔✔
• Chorea(HD)-bilateral Gpi✔
Gpi-
Globus
pallidus
interna

8. Target and effect
• Tremor-esp proximal tremor,rest tremor
• Rigidity,bradykinesia
• Lower L-Dopa-↓dyskinesia
STN
• Migraines
• Cluster headaches
Hypothalamus
• Depression
White matter
near Subgenual
Cingulate region

9. Target and effect
• OCD
Ventral
anterior limb
of IC
• Pain
• Cluster headache
• migraines
Ventral
striatum/STN

10. DBS device

11. Hardware:
1. DBS lead with four electrodes
2. Extension wire
3. Implantable pulse generator

12. DBS lead
⚫Inserted into target
⚫Fixed at skull with a ring and cap

13. Deep brain stimulation electrode configurations. (A) Conventional quadripolar electrode producing a spherical electrical field
that may spread outside the target area, causing side effects. (B) Multipolar 32 contact electrode that allows directional steering of the
field, reducing the potential for stimulation side effects. (C) Eight contact electrode with multiple independent current control (MICC),
enabling the allocation of completely different stimulation parameters independently to each electrode contact.

14. Intra-operative position of the guide tube and stylette

15. 2.Extension wire
⚫Pass from the scalp area under the skin to the chest

16. Electrode Location for Deep Brain Stimulation. Approved locations for implantation of deep brain stimulation (DBS) include
both the subthalamic nucleus and the internal segment of the globus pallidus. The pedunculopontine nucleus has showed promise as a
potential DBS target, especially in regards to axial symptoms such as gait and balance dysfunction. During implantation, a burr hole is
made in the skull through which the electrode is passed down to the target. An extension is tunneled under the skin of the scalp and
connected to an impulse generator located in the chest below the clavicle.

17. Implantable pulse generator-IPG
⚫A pacemaker-like device (unilateral Soletra or
bilateral Kinetra, Medtronic Activa, ITREL model)
⚫Can deliver pulses with adjustable parameters
(frequency, amplitude, width, modes, and polarities)
⚫Placed under the skin in the upper chest area near the
clavicle.
⚫Patient can activate or deactivate the DBS system by
placing a magnet or Access Review Device over the
chest area overlying the implantable pulse generator.

18. IPG
⚫The system can be turned on or off by the patient or
the clinician.
⚫ In addition, the clinician can select which one or
more of the four electrodes on each brain lead are to
be activated to provide electrical stimulation.
⚫This process allows electrical stimulation to be
delivered to a very precise part of the brain.

19. IPG battery
⚫The battery usually lasts between 2 and 5 years.
⚫The battery life varies depending on the settings
needed to control your symptoms.
⚫The Activa RC is a rechargeable IPG and will last up to
9 years.

21. Diagram of implanted DBS system (courtesy of Medtronic, inc. (used with permission)).

22. Post-op CT scan
DBS lead

26. Mechanism of action

27. Mechanism of benefits of DBS
⚫Exact –not known

28. Possible mechanism of action
1. Microlesioning
2. Disrupts the network (“jamming”)
3. Depolarization block
4. Functional ablation by desynchronizing a tremorigenic pacemaker
5. Preferential activation of large axons
6. Stimulation-evoked release of GABA, adenosine
7. Stimulation-induced (time-locked) modulation of pathological
network activity
8. Overriding of pathological bursts and oscillations and replacing
them with more regular fring
9. Activation and excitation of the target nucleus (rather than
inhibition as seen with lesioning)
10. Marked increase in the release of ATP, resulting in accumulation
of its catabolic product, adenosine

30. Complications
⚫Paresthesias
⚫Headache
⚫Disequilibrium
⚫Dysarthria Bilateral VIM DBS
⚫Dystonia
⚫Device failure-lead migration,fracture,disconnecction.
⚫Intra/peri op-seizures,ICH,infection,syncope,severe
cough,arrhythmia,confusion,headache,hallucination
⚫Risk of death is less than 1%.

31. Deep Brain Stimulation for Essential Tremor
⚫The first widespread use of DBS in the United States
and Europe was for the treatment of ET
⚫Most effective-Thalamic stimulation
⚫Average tremor reduction of over 80% in the majority
of patients
⚫If unilateral-Do unilateral Thalamic DBS
⚫If midline/ bilateral appendicular-Bilateral DBS

32. Deep Brain Stimulation for Parkinson
Disease
⚫Prolongs the ON time
⚫Improves axial and proximal bradykinesia.
⚫Reduction of dyskinesias
⚫Stimulate Ventral Gpi-for LD induced dyskinesias
⚫Stimulate Dorsal Gpi-for Bradykinesias
⚫Stimulation of STN suppress tremors

33. Selection of PD patients for deep brain
stimulation surgery
⚫Parkinson disease >5 years (to allow for atypical features
to emerge and assess response to dopaminergic therapy)
⚫Dopaminergic responsiveness (>30% reduction in motor
UPDRS)
⚫Troublesome dyskinesias despite optimal medical therapy
⚫Disabling medication resistant tremor
⚫Normal MRI
⚫Exclude atypical and secondary parkinsonism
⚫Exclude dementia and depression
⚫Good medical health
⚫Realistic expectations

37. How long do the benefits of DBS
last?
⚫The duration of DBS benefits varies from patient to
patient, but in the majority of cases it lasts many years.
⚫ Patients have now been followed for 10 or more years
with DBS, and the general rule has been that if the
symptoms still respond to dopaminergic medications,
then DBS will continue to work.
⚫ DBS also will continue to work long-term against
tremor and dyskinesia.

38. DBS is generally not appropriate
for people who:
⚫Have as the main disabling symptom trouble with balance,
walking, or freezing that is not helped by PD medication.
⚫Have as the primary disabling symptom trouble with
speech that is not helped with PD medications.
⚫Have confusion, disorientation, and/or difficulties with
memory and thinking on a daily basis.
⚫Have depression, anxiety, or another psychiatric illness
that has not improved or been stabilized with proper
therapy such as medication and counseling.
⚫Have a questionable PD diagnosis.
⚫Have another serious health condition, such as severe
heart or lung disease.

39. MRI after DBS- SAFE?
⚫Safe if <1.5 T, with only a head coil MRI
⚫ALWAYS check with implanted device specifications.
⚫ A total of 3304 PD patients with one or more DBS leads had a brain MRI scan, and 177 DBS patients
had a MRI of other body regions. In one case MRI was associated with a DBS battery failure without
neurological sequelae after battery replacement. No other complications were reported (Tagliati,
2009).

40. Other procedures:
⚫Electrocautery-only bipolar should be used
⚫USG-safe
⚫Cardiac pacemaker-safe,10 inch apart
⚫No lithotripsy
⚫Radiotherapy-with shield
⚫Never use or be near large power machinery, power
lines, arc welding equipment, electric steel furnaces,
induction heaters.

43. Recommendations for DBS
Based on a recent article in ‘Neurosurgery’ Jun 2018 ,Vol 82

44. Recommendations- based on:

45. QUESTION 1/7
Is bilateral subthalamic nucleus deep brain stimulation (STN DBS)
more, less, or as effective as bilateral globus pallidus internus
deep brain stimulation (GPi DBS) in treating motor symptoms of
Parkinson's disease, as measured by improvements in Unified
Parkinson's Disease Rating Scale, part III (UPDRS-III) scores?
⚫RECOMMENDATION
⚫Given that bilateral STN DBS is at least as effective as
bilateral GPi DBS in treating motor symptoms of
Parkinson's disease (as measured by improvements in
UPDRS-III scores), consideration can be given to the
selection of either target in patients undergoing
surgery to treat motor symptoms. (Level I)

46. QUESTION 2/7
Is bilateral STN DBS more, less, or as effective as
bilateral GPi DBS in allowing reduction of
dopaminergic medication in Parkinson's disease?
⚫RECOMMENDATION
⚫When the main goal of surgery is reduction of
dopaminergic medications in a patient with
Parkinson's disease, then bilateral STN DBS should be
performed instead of GPi DBS. (Level I)

47. QUESTION 3/7
Is bilateral STN DBS more, less, or as effective as bilateral
GPi DBS in treating dyskinesias associated with Parkinson's
disease?
RECOMMENDATION
⚫There is insufficient evidence to make a generalizable
recommendation regarding the target selection for
reduction of dyskinesias. However, when the reduction
of medication is not anticipated and there is a goal to
reduce the severity of “on” medication dyskinesias, the
GPi should be targeted. (Level I)

48. QUESTION 4/7
Is bilateral STN DBS more, less, or as effective as
bilateral GPi DBS in improving quality of life
measures in Parkinson's disease?
⚫RECOMMENDATION
⚫When considering improvements in quality of life in a
patient undergoing DBS for Parkinson's disease, there
is no basis to recommend bilateral DBS in 1 target over
the other. (Level I)

49. QUESTION 5/7
Is bilateral STN DBS associated with greater, lesser, or a
similar impact on neurocognitive function than
bilateral GPi DBS in Parkinson disease?
⚫RECOMMENDATION
⚫If there is significant concern about cognitive decline,
particularly in regards to processing speed and
working memory in a patient undergoing DBS, then
the clinician should consider using GPi DBS rather
than STN DBS, while taking into consideration other
goals of surgery. (Level I)

50. QUESTION 6/7
Is bilateral STN DBS associated with a higher, lower, or
similar risk of mood disturbance than GPi DBS in
Parkinson's disease?
⚫RECOMMENDATION
⚫If there is significant concern about the risk of
depression in a patient undergoing DBS, then the
clinician should consider using pallidal rather than
STN stimulation, while taking into consideration
other goals of surgery. (Level I)

51. QUESTION 7/7
Is bilateral STN DBS associated with a higher, lower, or
similar risk of adverse events compared to GPi DBS in
Parkinson's disease?
⚫RECOMMENDATION
⚫There is insufficient evidence to recommend bilateral
DBS in 1 target over the other in order to minimize the
risk of surgical adverse events.

52. Advantages & disadvantages

53. Advantages of DBS
⚫Immediate symptomatic and functional improvement
⚫Stimulation is adjustable and can be customized
⚫Lower risk of lesion-related complications
⚫Lower risk with bilateral procedure

54. Disadvantages of DBS
⚫Long-term outcome unclear
⚫Replacement of batteries
⚫Implantation of a foreign body (hardware)
⚫Cost to the patient*
⚫Limited coverage by Medicare and other insurance
carriers
*Costs around $60,000 per patient over 5yrs!!(ONLY)

55. Take home message
⚫DBS has been proven to be a safe, effective therapy for a
group of well-selected people with PD.
⚫DBS therapy is not a cure for PD, but it is a powerful
symptomatic treatment.
⚫ DBS is not a substitute for medications, and most patients
will not stop medications after the procedure.
⚫DBS can improve the motor symptoms of PD.
⚫As a rule, DBS will be effective against symptoms that
improve with medication.
⚫The DBS system consists of the lead, connecting wire,
implantable pulse generator (IPG), programmer, patient
controller, and/or magnet.

56. Thank you……