Neuromodulation : journal of the International Neuromodulation Society
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Substance addiction encompasses the incapacity to discontinue urgent drug use; many severely disabled patients might be considered appropriate candidates for surgery due to the high rates of relapse despite conservative treatment. A crucial finding in the brain of these patients is increased extracellular concentrations of dopamine in the nucleus accumbens (NAcc). ⋯ Despite available studies reporting a benefit in the treatment of drug addictions with NAcc surgery, this systematic review stresses the need for carefully planned prospective studies in order to further address the efficacy and indications.
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The hippocampus is thought to be involved in movement, but its precise role in movement execution and inhibition has not been well studied. Previous work with direct neural recordings has found beta-band (13-30 Hz) modulation in both movement execution and inhibition throughout the motor system, but the role of beta-band modulation in the hippocampus during movement inhibition is not well understood. Here, we perform a Go/No-Go reaching task in ten patients with medically refractory epilepsy to study human hippocampal beta-power changes during movement. ⋯ These findings indicate that increases in hippocampal beta power are associated with movement inhibition. To the best of our knowledge, this study is the first to report this phenomenon in the human hippocampus. The beta band may represent a state-change signal involved in motor processing. Future focus on the beta band in understanding human motor and impulse control will be vital.
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Deep brain stimulation (DBS) is an effective treatment for refractory obsessive-compulsive disorder (OCD). Neuropsychological assessment contributes to DBS treatment in several ways: it monitors the cognitive safety of the treatment, identifies beneficial or detrimental cognitive side effects, and it could aid to explain variability in treatment outcome, and possibly the treatment's working mechanism(s). ⋯ Although individual studies generally do not report cognitive deterioration after DBS for OCD, the variability of study designs and the multitude of cognitive measures used precluded a meta-analysis to confirm its safety and recognition of a cognitive pattern through which the efficacy of DBS for OCD might be explained. In the future, prospective studies should preferably include a standardized neuropsychological assessment battery specifically addressing executive functioning and have a longer-term follow-up in order to demonstrate the cognitive safety of the procedure. Such prospective and more uniform data collection may also contribute to our understanding of the working mechanisms of DBS in OCD.
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Our aim is to review several recent landmark studies discussing the application of advanced neuroimaging to guide target selection in deep brain stimulation (DBS) for psychiatric disorders. ⋯ Advanced neuroimaging techniques may be especially important to guide personalized DBS targeting in psychiatric disorders such as treatment-resistant depression and obsessive-compulsive disorder where symptom profiles and underlying disordered circuitry are more heterogeneous. These articles suggest that advanced imaging can help to further individualize and optimize DBS, a promising next step in improving its efficacy.
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Neuromodulatory devices are increasingly used by neurosurgeons to manage a variety of chronic conditions. Given their potential benefits, it is imperative to create clear ethical guidelines for the use of these devices. We present a tiered ethical framework for neurosurgeon recommendations for the use of neuromodulatory devices. ⋯ Weighing risks and benefits of providing neuromodulatory devices and assessing ability to remain responsible for the devices on the level of the individual patient indicate which patients are most likely to achieve benefit from these devices. Consideration of these factors on an axis of resource allocation will allow for optimal provision of neuromodulatory devices to patients in settings of varied resources. Neurosurgeons play a primary role in promoting the effectiveness of these devices.