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for people ages 21 years and up (full criteria)
at San Francisco, California
study started
estimated completion:



This study evaluates invasive deep brain stimulation (DBS) in the treatment of two types of chronic neuropathic pain, i) thalamic pain syndrome and ii) phantom limb pain. Participants will be implanted with recording / stimulation electrodes in pain-related circuits of the brain. Relief of pain symptoms with stimulation will be studied in both groups. It is hypothesized that neural signals will correlate with pain states and that DBS can disrupt these pain states in both groups, perhaps with differences in underlying neural mechanisms for pain relief.

Official Title

Deep Brain Stimulation (DBS) in Patients With Refractory Chronic Neuropathic Pain


The purpose of this study is to test the efficacy of DBS in a small cohort of patients with chronic pain refractory to conventional treatments. The study will involve the implantation of a neurostimulator, the Medtronic Activa PC+S device, to examine the efficacy of two modes of DBS. Open-loop DBS will provide stimulation based on a pre-set schedule, whereas closed-loop DBS will deliver stimulation based on brain activity associated with pain states. The goals of this study are to identify neurophysiological correlates of elevated pain states and find DBS parameters that disrupt pain-related brain activity and provide pain relief with little or no side effects. The efficacy of pain relief on subtypes of pain syndromes will also be studied.


Chronic Neuropathic Pain Post Stroke Pain Phantom Limb Pain Neuralgia Phantom Limb


You can join if…

Open to people ages 21 years and up

  • Age ≥ 21 years
  • Clinical diagnosis of thalamic pain syndrome (post-stroke) or phantom limb pain with allodynia or dysesthesia with pinprick anesthesia or hypoesthesia on the affected hemibody or limb (anesthesia dolorosa).
  • One year or more of medically refractory severe pain
  • Average daily pain for the past 30 days reported as >5 on a 0-10 numeric rating scale(NRS)
  • Failure to respond adequately to at least one antidepressant, one anti-seizure medication and one oral narcotic with current stable doses of medications.
  • For Post-Stroke Pain: MRI done within one year of the first visit showing a lesion that involves the contralateral brainstem, thalamus or cortex. The lesion will involve cortical-subcortical areas in topography consistent with sensory thalamocortical connections. This will include patients with infarcts in the territory of the middle cerebral artery or those with cavernous malformations. A more recent MRI may be required if the patient's condition changed within the previous year.
  • For Phantom limb pain: MRI done within one year not showing any contraindication to surgery such as mass, lesion, hemorrhage or other abnormality near target
  • Capable of understanding and providing informed consent
  • Women of childbearing age must be on regular use of an accepted contraceptive method(s).
  • Ability to speak / read English
  • Previous surgical procedures: Patients with severe and refractory chronic pain syndrome may have undergone other interventional or surgical procedures as an attempt to alleviate pain. Surgical procedure may include blocks, spinal cord stimulation,cortical peripheral ablative procedures or cerebral ablative procedures. In this study, patients with previously implanted cortical stimulation systems, or spinal and peripheral nervous system stimulation systems may be included. Patients with prior DBS systems will not be considered candidates. However, patients with previous motor cortex stimulation may be considered but must have had the cortical stimulation system inactivated or removed before being considered a candidate for this protocol. Removal of the cortical stimulation system will not be covered under this protocol. Patients with a spinal or peripheral neuromodulation system may be included provided that the implanted systems are compatible with the all research protocols (including MRI) to be performed during the research. Patients with previous DBS implants will not be considered candidates.

You CAN'T join if...

  • Pregnancy or breast feeding
  • Inability to speak and / or read English
  • Inability to give consent
  • Aphasia severe enough to limit the consent process or communication between the investigators and the patient. Patients with mild or recovering aphasia may be considered candidates at the discretion of the PI.
  • Significant cognitive impairment or Dementia (MoCA < 25)
  • Active depression (BDI > 20) or other untreated or uncontrolled psychiatric illness(active general anxiety disorder, schizophrenia, bipolar disorder,obsessive-compulsive disorder (OCD), or personality disorders (e.g. multiple personality disorder, borderline personality disorder, etc.) or other neuropsychiatric conditions that evaluating psychiatrist would recommend exclusion of patient after neuropsychiatric evaluation.
  • Coagulopathy. Patients will be excluded unless assessed and cleared by hematology.
  • Inability to stop Coumadin or platelet anti-aggregation therapy for surgery and after surgery. Patients taking these medications will need to discuss the need/risk of continuing these medications with their physicians and the PI or study personnel may contact the treating physician(s) as well to discuss the risks of anticoagulation /antiaggregation therapy discontinuation.
  • Pregnancy or lack of regular use of contraceptives. Patients who become pregnant after enrollment may be excluded from the study. Patients who become pregnant prior to the surgical implantation of the DBS systems will be excluded from the study.
  • Major medical co-morbidities including uncontrolled hypertension, major organ system failure, immunocompromised state or malignancy with < 5 years life expectancy
  • Major neurological disorder other than the one that led to the chronic pain including epilepsy, or neurodegenerative condition
  • MRI (done within one year of the first visit) with abnormalities other than those associated with the neurological disorder causing chronic pain.
  • Previous ablative intracranial surgery for the management of the thalamic pain syndrome.
  • Previously implanted with deep brain stimulation system.
  • Concurrent enrolment in any other trial / study for chronic pain.
  • Implantable hardware not compatible with MRI or with the study.
  • Patients may be excluded from enrollment due to a condition that, in the judgment of the PI, significantly increases risk or reduces significantly the likelihood of benefit from DBS.
  • Suicide attempt </= 12 months or imminent suicide risk
  • History of substance abuse
  • Requires diathermy, electroconvulsive therapy (ECT) or transcranial magnetic stimulation (TMS) to treat a chronic condition
  • Has an implanted electronic device such as a neurostimulator, cardiac pacemaker or medication pump
  • Allergies or known hypersensitivity to materials in the Activa PC+S system (i.e.titanium, polyurethane, silicone, polyetherimide, stainless steel).


  • University of California accepting new patients
    San Francisco, California, 94143, United States


accepting new patients
Start Date
Completion Date
University of California, San Francisco
Lead Scientists
Edward Chang
Prasad Shirvalkar
Study Type
Last Updated
October 12, 2017
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