DBS Engleza

Deep Brain StimulationDeep Brain StimulationMoise Flaviu-LaurentiuMoise Flaviu-Laurentiu Musat Stefan Musat Stefan Vladareanu Vladareanu

AndreeaAndreeaMiron BiancaMiron Bianca Miron CosminaMiron Cosmina Ungureanu MadalinaUngureanu Madalina

Tunaru AdelinaTunaru Adelina Mila Georgiana Mila Georgiana Miinea IrinaMiinea Irina

Treatment of Parkinson’s Disease

Brief HistoryBrief History

Deep brain stimulation (DBS) is a surgical treatment involving the implantation of a medical device called Deep brain stimulation (DBS) is a surgical treatment involving the implantation of a medical device called a brain pacemaker, this pacemaker sends electrical impulses to specific parts of the brain. DBS in select a brain pacemaker, this pacemaker sends electrical impulses to specific parts of the brain. DBS in select

brain regions has provided therapeutic benefits for otherwise treatment-resistant movement and brain regions has provided therapeutic benefits for otherwise treatment-resistant movement and affective disorders such as chronic pain, Parkinson's disease, tremor and dystoniaaffective disorders such as chronic pain, Parkinson's disease, tremor and dystonia

Relevant Brain Relevant Brain StructuresStructures

Motor CircuitMotor Circuit

Parkinson’s DiseaseParkinson’s Disease

InterventionIntervention

Patient SelectionPatient Selection Goal:Goal: Find ideal patients, where individual benefit Find ideal patients, where individual benefit

> risk of surgery> risk of surgery Advanced idiopathic PD with motor complications is Advanced idiopathic PD with motor complications is

main indication for DBS in PDmain indication for DBS in PD Multidisciplinary approach:Multidisciplinary approach:

1. Neurosurgeon1. Neurosurgeon2. Neurologist2. Neurologist3. Neuropsychologist3. Neuropsychologist

InterventionIntervention

Patient SelectionPatient Selection Response to levodopa = best prognostic indicator Response to levodopa = best prognostic indicator

for DBS suitabilityfor DBS suitability Neuropsychological evaluationNeuropsychological evaluation

- Depression- Depression- Psychosis- Psychosis

Age Age Full medical assessmentFull medical assessment Discussion of long-term and short-term effects of Discussion of long-term and short-term effects of

DBSDBS Education regarding environmental concerns with Education regarding environmental concerns with

implantable devicesimplantable devices

InterventionIntervention

Surgical ProcedureSurgical Procedure Precise implantation of stimulation Precise implantation of stimulation

electrode in targeted brain area.electrode in targeted brain area. Connecting electrode to internal Connecting electrode to internal

programmable pulse generatorprogrammable pulse generator

NeurobiologyNeurobiology

Brain areas targeted in DBS:Brain areas targeted in DBS:1. Vim = ventralis intermedius nucleus of

the thalamus2. GPi = posteroventral portion of the

internal segment of the globus pallidus 3. STN = subthalamic nucleus

InterventionInterventionPre-Operative Stage:Pre-Operative Stage: Stereotactic SurgeryStereotactic Surgery

- Locate targeted brain areas- Locate targeted brain areas- Stereotactic frame- Stereotactic frame- MRI, CT, or ventriculography- MRI, CT, or ventriculography- Stereotactic atlas- Stereotactic atlas

InterventionIntervention Optimal Stimulation Optimal Stimulation

Sites:Sites:- Dorsolateral STN border- Dorsolateral STN border- Posteroventral GPi- Posteroventral GPi

DBS electrode stereotactically inserted with DBS electrode stereotactically inserted with special rigid guide tubespecial rigid guide tube

Patient is awake and in the medication-“off” Patient is awake and in the medication-“off” state after 12-hour withdrawal state after 12-hour withdrawal

Implantation of Electrode:Implantation of Electrode:

InterventionIntervention

Electrode has 4 Electrode has 4 contacts on its distal contacts on its distal endend

The effects of The effects of stimulation from stimulation from each combination of each combination of 2 contacts or 2 contacts or monopolarly from monopolarly from each contact are each contact are assessedassessed- Determine best - Determine best contact(s) to use to contact(s) to use to obtain optimal obtain optimal therapeutic benefittherapeutic benefit

Implantation of Electrode:Implantation of Electrode:

InterventionIntervention

Electrode Electrode Extension Extension (passed under skin to chest) (passed under skin to chest) Chest: Battery-operated Chest: Battery-operated stimulatorstimulator

Patient turns stimulator “on” Patient turns stimulator “on” and “off” by passing magnet and “off” by passing magnet over the skin overlying over the skin overlying stimulator stimulator

Typical stimulator settings:Typical stimulator settings:- Voltage amplitude: 2-3 V- Voltage amplitude: 2-3 V- Pulse width: 90 - Pulse width: 90 μμss- Stimulation frequency: 130-- Stimulation frequency: 130-185 Hz185 Hz

Electrode-Stimulator Connection:Electrode-Stimulator Connection:

InterventionIntervention

Stimulator parametersStimulator parameters adjusted via a computer-adjusted via a computer-controlled probe controlled probe placed placed over stimulatorover stimulator

Pulse generator can be Pulse generator can be adjusted post-operatively adjusted post-operatively by telemetry: by telemetry: (1) Electrode (1) Electrode configuration, (2) Voltage configuration, (2) Voltage amplitudeamplitude(3) Pulse width(3) Pulse width(4) Frequency (4) Frequency

Electrode-Stimulator Connection:Electrode-Stimulator Connection:

Mechanisms of DBSMechanisms of DBS

The exact mechanisms underlying the The exact mechanisms underlying the beneficial effects of DBS are still unknown.beneficial effects of DBS are still unknown.

Logistical fallacy exists.Logistical fallacy exists.

Many hypotheses exist regarding the Many hypotheses exist regarding the mechanisms underlying high-frequency mechanisms underlying high-frequency stimulation.stimulation.

Advantages of DBSAdvantages of DBS

Avoid adverse side effects associated with Avoid adverse side effects associated with lesioning procedureslesioning procedures

Does not require deliberate destruction of brain Does not require deliberate destruction of brain regionsregions

Effects of stimulation therapy are reversibleEffects of stimulation therapy are reversible- Due to reversibility, does not preclude use of - Due to reversibility, does not preclude use of future therapiesfuture therapies

Can change stimulation parameters to optimize Can change stimulation parameters to optimize clinical benefit clinical benefit

Advantages of DBSAdvantages of DBS

Can be safely performed bilaterally (in contrast to Can be safely performed bilaterally (in contrast to ablative procedures)ablative procedures)

May be the only effect treatment of levodopa-May be the only effect treatment of levodopa-induced dyskinesiasinduced dyskinesias

The beneficial changes are long-lastingThe beneficial changes are long-lasting

Disadvantages of DBSDisadvantages of DBS

Adverse side effects related to surgeryAdverse side effects related to surgery- Intra-cranial hemorrhage- Intra-cranial hemorrhage- Pulmonary embolism, chronic subdural hematoma, venous - Pulmonary embolism, chronic subdural hematoma, venous infarction, seizureinfarction, seizure

Adverse effects related to electrical stimulationAdverse effects related to electrical stimulation- Electrical current could spread into adjacent - Electrical current could spread into adjacent structures, leading to tonic muscle contraction, structures, leading to tonic muscle contraction, dysarthria, paraesthesia, worsening of akinesia, dysarthria, paraesthesia, worsening of akinesia, etc.etc.

Hardware related failureHardware related failure- Lead extension fracture, lead migration, short or open circuit, - Lead extension fracture, lead migration, short or open circuit, malfunction of pulse generator, infection, etc.malfunction of pulse generator, infection, etc.

Disadvantages of DBSDisadvantages of DBS

Post-operative adverse side effects are commonPost-operative adverse side effects are common- W- Weight gaineight gain - Muscle contractions- Muscle contractions- D- Dyskinesiayskinesia - Paresthesia - Paresthesia - A- Axial symptomsxial symptoms - Speech dysfunction - Speech dysfunction - Eyelid, ocular, visual disturbances- Eyelid, ocular, visual disturbances- B- Behavioral and cognitive problemsehavioral and cognitive problems (e.g. mood disorders) (e.g. mood disorders)

Long-term complicationsLong-term complications- Infection or erosion- Infection or erosion - Tolerance- Tolerance- Pain and discomfort- Pain and discomfort - Development of - Development of dementiadementia- Sudden loss of effect- Sudden loss of effect

Costs of surgeryCosts of surgery

Cannot use sham surgeries as controlsCannot use sham surgeries as controls

ConclusionConclusion Although the pathophysiology of PD has been well studied Although the pathophysiology of PD has been well studied

and determined, there are many aspects which are still and determined, there are many aspects which are still unknown. Future research should be directed at the exact unknown. Future research should be directed at the exact mechanisms by which DBS exerts its beneficial effects. It mechanisms by which DBS exerts its beneficial effects. It may be possible that one of the hypotheses for the may be possible that one of the hypotheses for the mechanism of action already discussed is in fact correct. mechanism of action already discussed is in fact correct.

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