Chronic neuropathic pain is a common disabling condition
affecting many patients. Spinal cord stimulation (SCS) is a safe
and effective therapeutic option for individuals who suffer from
intractable neuropathic pain. Neuropathic pain perception
involves a complex interface between the cognitive, emotional
and sensory circuitry in the brain. The use of functional MRI
(fMRI) to understand neuropathic pain and its relief by SCS is
an important area of study. However, fMRI with SCS has been
challenging to perform given the safety concerns of heating with
MR imaging and implanted neurostimulators.
In collaboration with Medtronic, and The Wright Center for
Innovation in Biomedical Imaging, we have been able to
demonstrate the safety of conducting 3T f MRI studies in patients
with implanted SCS. Subsequently, we performed an f MRI study to
investigate the mechanism of neuropathic pain relief associated
with SCS. The study involved 10 subjects with complex regional
pain syndrome or failed back surgery neuropathic leg pain with
epidural spinal cord stimulator implants. Optimum stimulator
settings were determined for each study participant reporting
significant pain improvement with SCS. Resting state functional
connectivity fMRI analysis was performed with SCS OFF vs.
SCS ON with therapeutic benefit. The results demonstrated
that pain relief with SCS is associated with reduced resting
state connectivity between the somatosensory and limbic brain
networks and modulation of the affective component of pain.
Additional studies are under way to further understand these
mechanisms and to determine the utility of f MRI as a biomarker
to help patient selection and monitor treatment outcomes of SCS.
Milind Deogaonkar, MD
Deogaonkar M, Sharma M, Oluigbo C, Nielson DM, Yang X, Vera-Portocarrero L, Molnar GF, Abduljalil A, Sederberg PB, Knopp M, Rezai AR:
Spinal Cord Stimulation (SCS) and Functional Magnetic Resonance Imaging (f MRI): Modulation of Cortical Connectivity with Therapeutic SCS.
Neuromodulation. 2015 Sep 16; [Epub ahead of print].
Optimal pain relief using SCS reduces the affective component of pain and is associated
with decreased connectivity between the somatosensory and limbic regions of the brain