Neuromodulation : journal of the International Neuromodulation Society
-
Nonpulsatile tinnitus is an auditory phantom percept characterized as a tone, or a noise-like sound such as a hissing or buzzing sound or polyphonic, in the absence of any objective physical sound source. Although advances have been made in symptomatic pharmacologic and nonpharmacologic treatments, these treatments are unable to eliminate the tinnitus sensation in most patients. A novel approach using noninvasive and invasive neuromodulation has emerged as an interesting and promising modality for tinnitus relief. ⋯ Although the different techniques introduced revealed promising results, further research is needed to better understand how these techniques work and how the brain responds to neuromodulation. More sophisticated stimulation regimens and parameters should be developed to dynamically stimulate various regions at different frequencies and intensities, physiologically tailored to the patient's brain state in an attempt to maximize efficacy.
-
Review Meta Analysis
Analgesic effects of noninvasive brain stimulation in rodent animal models: a systematic review of translational findings.
Noninvasive brain stimulation (NIBS) interventions have demonstrated promising results in the clinical treatment of pain, according to several preliminary trials, although the results have been mixed. The limitations of clinical research on NIBS are the insufficient understanding of its mechanisms of action, a lack of adequate safety data, and several disparities with regard to stimulation parameters, which have hindered the generalizability of such studies. Thus, experimental animal research that allows the use of more invasive interventions and creates additional control of independent variables and confounders is desirable. To this end, we systematically reviewed animal studies investigating the analgesic effects of NIBS. In addition, we also explored the investigation of NIBS in animal models of stroke as to compare these findings with NIBS animal pain research. ⋯ We found a limited number of animal studies for both pain and stroke NIBS experimental research. There is a lack of safety data in animal studies in these two topics and results from these studies have not been yet fully tested and translated to human research. We discuss the challenges and limitations of translating experimental animal research on NIBS into clinical studies.
-
Transcranial magnetic stimulation (TMS) is a well-established clinical protocol with numerous potential therapeutic and diagnostic applications. Yet, much work remains in the elucidation of TMS mechanisms, optimization of protocols, and in development of novel therapeutic applications. As with many technologies, the key to these issues lies in the proper experimentation and translation of TMS methods to animal models, among which rat models have proven popular. A significant increase in the number of rat TMS publications has necessitated analysis of their relevance to human work. We therefore review the essential principles for the approximation of human TMS protocols in rats as well as specific methods that addressed these issues in published studies. ⋯ Rat TMS has several limitations when considering parallels between animal and human stimulation. However, it has proven to be a useful tool in the field of translational brain stimulation and will likely continue to aid in the design and implementation of stimulation protocols for therapeutic and diagnostic applications.
-
Central thalamic deep brain stimulation (CT-DBS) may have therapeutic potential to improve behavioral functioning in patients with severe traumatic brain injury (TBI), but its use remains experimental. Current research suggests that the central thalamus plays a critical role in modulating arousal during tasks requiring sustained attention, working memory, and motor function. The aim of the current article is to review the methodology used in the CT-DBS protocol developed by our group, outline the challenges we encountered and offer suggestions for future DBS trials in this population. RATIONAL FOR CT-DBS IN TBI: CT-DBS may therefore be able to stimulate these functions by eliciting action potentials that excite thalamocortical and thalamostriatal pathways. Because patients in chronic minimally conscious state (MCS) have a very low probability of regaining functional independence, yet often have significant sparing of cortical connectivity, they may represent a particularly appropriate target group for CT-DBS. PIlOT STUDY RESULTS: We have conducted a series of single-subject studies of CT-DBS in patients with chronic posttraumatic MCS, with 24-month follow-up. Outcomes were measured using the Coma Recovery Scale-Revised as well as a battery of secondary outcome measures to capture more granular changes. Findings from our index case suggest that CT-DBS can significantly increase functional communication, motor performance, feeding, and object naming in the DBS on state, with performance in some domains remaining above baseline even after DBS was turned off. ⋯ The use of CT-DBS in patients in MCS, however, presents challenges at almost every step, including during surgical planning, outcome measurement, and postoperative care. Additionally, given the difficulties of obtaining informed consent from patients in MCS and the experimental nature of the treatment, a robust, scientifically rooted ethical framework is resented for pursuing this line of work.
-
Randomized Controlled Trial
Temporal profile of functional visual rehabilitative outcomes modulated by transcranial direct current stimulation.
We have previously reported that transcranial direct current stimulation (tDCS) delivered to the occipital cortex enhances visual functional recovery when combined with three months of computer-based rehabilitative training in patients with hemianopia. The principal objective of this study was to evaluate the temporal sequence of effects of tDCS on visual recovery as they appear over the course of training and across different indicators of visual function. ⋯ These results suggest that tDCS may differentially affect the magnitude and sequence of visual recovery in a manner that is task specific to the type of visual rehabilitative training strategy employed.