The Nucleus Accumbens as a Potential Target for Central Poststroke Pain

Abstract

Although deep brain stimulation (DBS) has been found to be efficacious for some chronic pain syndromes, its usefulness in patients with central poststroke pain (CPSP) has been disappointing. The most common DBS targets for pain are the periventricular gray region (PVG) and the ventralis caudalis of the thalamus. Despite the limited success of DBS for CPSP, few alternative targets have been explored. The nucleus accumbens (NAC), a limbic structure within the ventral striatum that is involved in reward and pain processing, has emerged as an effective target for psychiatric disease. There is also evidence that it may be an effective target for pain. We describe a 72-year-old woman with a large right hemisphere infarct who subsequently experienced refractory left hemibody pain. She underwent placement of 3 electrodes in the right PVG, ventralis caudalis of the thalamus, and NAC. Individual stimulation of the NAC and PVG provided substantial improvement in pain rating. The patient underwent implantation of permanent electrodes in both targets, and combined stimulation has provided sustained pain relief at nearly 1 year after the procedure. These results suggest that the NAC may be an effective DBS target for CPSP.

The Nucleus Accumbens: A Comprehensive Review

“…The success of DBS in improving motor function in dystonia, essential tremor, and Parkinson's disease [320,321], with better stability and fewer adverse effects compared with lesioning, has opened the door for trials evaluating its efficacy in treating a host of neurologic and psychiatric disorders. There have been a number of studies evaluating DBS of the NAc for the treatment of obsessive-compulsive disorder [310,316,322], Tourette syndrome [311,323,324,325], depression [303,304,305], addiction to certain drugs of abuse, including alcohol [312,326,327,328,329], heroin [330], and nicotine [313], and central pain syndrome [331,332]. Given the known connections outlined above, it is not surprising that a recent large animal study supported the influence of NAc DBS on a variety of brain structures which could influence these and other psychiatric disorders [333].…”

Deep Brain Stimulation for Chronic Pain

“…However, there is no clear follow-up work on targeting the parabrachial region for DBS to alleviate chronic pain. More recently, Mallory and colleagues 124 targeted the NAcc ventral striatum in a case report of central poststroke pain, noting success when combining NAcc stimulation with commiserate PV(A)G stimulation (although they report stimulating the NAcc alone helps alleviate pain). Finally, targeting the affective components of pain, Boccard and colleagues 125 recently reported success when stimulating the anterior cingulate cortex of a patient with neuropathic pain.…”

Deep Brain Stimulation for the Treatment of Dejerine-Roussy Syndrome

“…One patient achieved successful pain reduction with sole stimulation of the accompanying target [49]. Interestingly, combined implantation into the PVG and the NAcc was effective in providing complete pain relief, possibly due to inhibitory projections to the medial thalamus, the amygdala, and the PAG [68,69,70,71]. Individual patient data was not provided in the larger cohort described by Boccard et al [60] and, although they found a statistically significant VAS score decrease of 38%, the data may have been artificially elevated by excluding patients who did not achieve significant pain relief [60].…”