Therapeutic options for the recovery of severely brain injured patients: the field of neuromodulation
Neuromodulation techniques aimed at normalizing the neurophysiologic disturbance produced by brain lesions or dysfunction. They have been studied for years in attempts to modulate brain activity to treat several neurological diseases. The field of (non-)invasive brain stimulation offers a valuable alternative to improve the recovery of severely brain injured patients with disorders of consciousness (DOC), a population that lacks of effective treatment options, especially at the chronic stage.
In this symposium, we will expose the neural mechanisms of neuromodulation and how these novels techniques can, from a mechanistically point of view improve the recovery of severely brain injured patients. We will also describe non-invasive and invasive brain stimulation techniques, namely transcranial direct current stimulation (tDCS), ultrasound stimulation and deep brain stimulation (DBS), as therapeutic options for patients with DOC. The first studies on tDCS, targeting the left prefrontal cortex, have shown encouraging results, with significant behavioral improvements, in both acute and chronic patients. More recent studies targeting other brain regions (e.g., posterior parietal or motor cortex) or aiming at better understand the mechanisms of action of tDCS (using neuroimaging techniques) in severely brain injured patients have also been performed, confirming the clinical potential of tDCS in this population of patients. Other cutting edge technology, such as ultrasound stimulation, starts to be investigated as well and has shown promising results as treatment for patients with DOC. Finally, DBS, well known for the treatment of Parkinson Disease, has shown to induce extensive behavioral enhancement (emergence from the minimally conscious state) after the implantation of an electrical stimulator in the intralaminar nuclei (thalamus) in case reports.
Even if more work has to be done to strengthen our understanding of the mechanisms and potential treatments to promote the recovery of consciousness in patients with DOC, the field of neuromodulation seems to be a promising therapeutic option to improve patients’ rehabilitation.
In this symposium we aim at (i) giving the basics of mechanisms of action of (non)-invasive brain stimulation techniques, (ii) giving on overview of what has been done so far in research, as well as (iii) presenting the newest promising technologies for the treatment of patients with DOC.