Deep Brain Stimulations in Cases of Prolonged Post-traumatic Unconsciousness

Electrical modulation of neuronal networks in brain-injured patients with disorders of consciousness: A systematic review

“…The main concern is methodology weaknesses in most reports, as observational studies deliver a low grade of evidence [34]. Furthermore, the technology was still fairly rudimentary when the first reports were published, with no implantable device available for long-term chronic DBS [14][15][16] and first-generation electrodes that had a non-coaxial stylet pulling the electrode into the brain [17,20]. Finally, postoperative analysis of effective contact location is not available.…”

“…From 1985, poor results prompted Cohadon et al [18] to remain cautious over a technique that only offered "half-way recovery", and even now, 28 years later, there is still a host of unresolved issues for future clinical trials, notably to determine the most effective functional deep brain target(s), optimal stimulation parameters, and candidate responder selection criteria. It is particularly important to be able to screen the responders for the best candidates liable to gain substantial benefit from DBS, -although what 'substantial' means for this patient population needs to be defined with care and revised continually in response to on-going clinical, research and societal advances.…”

“…The goal of this systematic review is to summarize key data from all the clinical DBS trials that aimed to alleviate post-brain injury disorders of consciousness -three case reports [14][15][16], two observational series [17][18][19][20][21] and one crossover study [22] published between 1968 and 2010. The thalamus, tegmentum and pallidum were targeted for electrode implantation (Table 1) as the thalamus and tegmentum belong to the reticular-thalamic activating complex involved in arousal and consciousness [23][24][25] and as pallidum stimulation provokes arousal in cats and human [15,26].…”

“…Cohadon et al [17,18] published reports in 1984 and 1985 on the first series of 6 vegetative patients implanted 6 to 15 months after traumatic brain injury. Electrodes were intended to be placed in the centromedian nucleus of the right thalamus.…”

“…The Bordeaux-based team then reported the whole series of 25 (23 trauma) neurovegetative patients in 1993 [19]. In the wake of the first series [17,18], they considered nonresponse after DBS could be an argument for definitive chronic vegetative status, and so after securing national ethical review board approval, they continued to implant patients, starting at the 3rd month postinjury in cases showing no clinical evolution. Intended target was slightly different, as this time they aimed for the CMPf.…”