Tue. Kim, Sang Kyong CH.6(2) Deep Brain Stimulation for Pain Management Neural Engineering Special thanks to

Indications and Patients Selection Patients for DBS Chronic intractable pain Pain in the lower extremities and back Spinal cord stimulation Less demanding procedure  Better choice than DBS Pain located in the upper half of the body Head, face, neck DBS Unilateral pain VPL/VPM/IC Stimulation On the side contralateral to stimulation Neurogenic pain PVG stimulation

3 6.5 Patients for DBS Deafferentation pain VPL/VPM/IC stimulation IC stimulation : More effective! Pain from brain injury Stroke, trauma, etc. Pain that has not responded to other modalities? Such as spinal cord stimulation or other techniques Invalid selection criteria! Does not follow that DBS will be effective Indications and Patients Selection

4 6.6 Preoperative processes prior to consideration for surgery Psychologic test – Depression, Anxiety, Psychosis Detoxification from all narcotic medication PVG electrode placement Thalamic and IC placement Chronic stimulation Technique

PVG

Thalamic and Internal Capsule

7 Thalamic and Internal Capsule Placement 6.6.2

8 Thalamic and Internal Capsule Placement

PVG stimulation 20~30Hz Only small elevation of its activity Most patients cannot feel any side effects Rarely requires adjustment VPL/VPM/IC stimulation Often requires adjustment Depression Reduction of brain serotonin and norepinephrine levels Antidepressants Chronic Stimulation

Troubleshooting : Patients PVG/IC stimulation effect inhibition Use of drugs (ex.narcotic) Depression Depletion of serotonin and norepinephrine Use of antidepressants (ex.trazodone, amitriptyline) Stress (anxiety, grief) Loss of pain relief for unknown reason Stimulator off for approximately 2 weeks Stop medications (antidepressants) Instead, L-dopa for norepinephrine production L-tryptophan for serotonin production

Failure of the insulation or electrical wiring Burning sensation over the wiring or connectors Leakage of current through the insulation 2. Skin erosion over the electrode 3. Fracture of the wiring and failure of electrical contact Fixation point, usually at the locking plug under the scalp 4. Fracture of the electrode or extension wiring Associated with trauma, such as a motor vehicle accident that produces snapping of the head and neck 5. Battery depletion 6. Failure of stimulation system Pain relief remains for about 10 days Troubleshooting : Device

Complications and Side Effects Infection Less common as more experience has been obtained Development of equipment  reducing skin erosion Intraoperative antibiotics Closure with skin clips that do not perforate the skin Cerebral Hemorrhage Smooth surface  Prevents from adhering to tissue Neurological side effects ptosis, hypesthesia, paresis, dysphoria, dysphasia, confusion… Electrode placement & Shorter operating time Headache Still an enigma Aggravation of discomfort Patient describing paresthesia as pain