engleski

Deep brain stimulation for treatment patients in vegetative state and minimally conscious state

Introduction: An effective treatment of minimal conscious state (MCS) and vegetative state (VS), caused by hypoxic encephalopathy (HE) or traumatic brain injury (TBI), has not been yet revealed. Several studies with deep brain stimulation of thalamic nuclei in MCS and VS patients were published with most patients after TBI. The aim of our study is to find out the possibility of DBS as a therapy for patients in VS or MCS particularly in earlier phase when the irreversible changes of muscles and joints are not so pronounced. Methods: Fourteen patients were included four patients with TBI and 10 with HE. Four of them were in MCS and 10 in VS. Entry criteria included an evaluation neurological status including Rappaport Coma/Near coma scale, electrophysiological status with multimodal evoked potential and 12/24 hours of EEG, and neuroimaging (positron emission tomography and magnetic resonance imaging). The stimulation target was centromedian- parafascicular nucleus complex in the left hemisphere or more preserved hemisphere in patients with TBI. Patients were stimulated daily for 30 minutes every three hours. The parameters of stimulation were as follows: monopolar, intensity to induce "arousal reaction", frequency 25-30 Hz, pulse duration 220 µs. Follow up was from 30 to 54 months. Results: Two MCS patients regained consciousness, walking without help, speaking fluently with impressive speech comprehension and no need for assistance in everyday life. One MCS patient reach to the level of consciousness however she is still in wheelchair. One VS patient after ischemic lesion improved to the level of consciousness with possibility of nonverbal communication. Three VS patients died from respiratory infection or sepsis. Other 7 patients, six in VS and one in MCS, remained without substantial improvement of consciousness. Conclusion: For the VS or MCS patients that fulfill clinical, neurophysiological and neuroimaging criteria the DBS of thalamic nuclei could be advised as an option and could be started at rather early stage. We did not figure out neurophysiologic, imaging or clinical marker(s) predicting recovery of patients having very similar features. The studies, which could solve these dilemmas, have to be designed not only using reliable scientific methods but also solving some ethical questions which are specific and more demanding in VS and MCS patients than others.

DBS ; vegetative state ; minimal consciousness state

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