The Current State of Deep Brain Stimulation for Chronic Pain and Its Context in Other Forms of Neuromodulation

Abstract

Chronic intractable pain is debilitating for those touched, affecting 5% of the population. Deep brain stimulation (DBS) has fallen out of favour as the centrally implantable neurostimulation of choice for chronic pain since the 1970–1980s, with some neurosurgeons favouring motor cortex stimulation as the ‘last chance saloon’. This article reviews the available data and professional opinion of the current state of DBS as a treatment for chronic pain, placing it in the context of other neuromodulation therapies. We suggest DBS, with its newer target, namely anterior cingulate cortex (ACC), should not be blacklisted on the basis of a lack of good quality study data, which often fails to capture the merits of the treatment.

Current and future directions of deep brain stimulation for neurological and psychiatric disorders

“…In contrast to typical DBS stimulation parameters, the stimulation frequencies have typically been lower because DBS of the thalamus or PAG at lower frequencies (< 50 Hz) is believed to cause analgesia, whereas higher frequencies (> 70 Hz) result in hyperalgesia. 30 However, even if one is able to lower pain intensity (i.e., visual analog scale scores), this does not always correlate to overall benefits in quality of life, 1 further emphasizing the need to better understand the underlying neural circuitry and network interactions.…”

Where We Come From and Are We Aware of Where We Are Going To?

“…The anaesthetists have taken over [50] and provided a large selection of minimally invasive techniques and revolutionised the percutaneous and oral management of chronic pain [51]. The surgical techniques of pain management have been slowly obliterated [52] in favour of those that involve peripheral or central nervous system stimulation [53,54] and intrathecal or epidural drug administration [55][56][57]. In posterior spinal cord stimulation procedures, it has been proven that the surgically implanted pad electrodes provide better results than the needle-inserted ones [58].…”

A Deep Brain Stimulation Trial Period for Treating Chronic Pain

“…The trial period affords the opportunity to explore multiple pain-relevant brain regions based on pre-clinical and human experience to select the sites most appropriate for the pain syndrome and patient. In a survey of the current state of DBS for chronic pain, Farrell et al focus on three prominent brain targets that have been tested most frequently: the ventral posterolateral/medial thalamus (VPL/VPM), the periventricular/periaqueductal grey (PVG/PAG), and the anterior cingulate cortex (ACC) across a wide variety of chronic pain syndromes [ 7 ]. Most studies highlighted in that review used a simple readout of somatic pain intensity (numeric or visual analog rating scale (NRS, VAS)); however, this approach fails to measure changes in the affective or cognitive domains of pain.…”

“…There are numerous factors to consider in the experimental design of a trial period: the duration of a trial period, how many patients to enroll, and outcome metrics of interest. Indeed, prior studies of DBS and chronic pain may have failed to reach primary endpoints because of nonrandomized design, heterogeneous patient populations, subjective assessment of patient outcomes, lack of measuring “meaningful” changes in symptoms, inconsistencies in sites stimulated, and other factors (see review [ 7 ]). Practical considerations should not be left to last minute planning.…”