[Recovery of consciousness as manifestation of neuroplasticity]

Prolonged impairment of consciousness is one of the most fearsome syndromes during diseases and traumas of nervous system. Traumatic brain injury (TBI) is the cause of coma with outcome in vegetative state in approximately half of cases which allows considering this etiopathogenetic form of consciousness impairment as one of the models for studying its morphofunctional nature because the pathogenesis of TBI is mostly understood. Particularly, it has been showed that in the basis of clinical picture of TBI lie, on the one hand, morphological (diffuse axonal injury of subcortical white matter, necrotic changes in cortex, thalamus) and functional (diaschisis) disturbances and on the other--processes of sanogenesis occurring within the borders of neuroplasticity. The aim of our research was to investigate clinical and neurophysiological markers of consciousness recovery in patients with vegetative state (VS) after severe TBI by comparison of clinical changes dynamics and brain bioelectrical activity. In all patients we have evaluated neurological status, Glasgow coma scale, performed registration and spectral-coherent analysis of electroencephalography and also registration and analysis of somatosensory potentials, studied motor thresholds, amplitude-time characteristics of evoked motor potentials during transcranial magnetic stimulation, repeatedly conducted MRI or CT. The electroencephalography in most of the patients revealed theta- and delta-rhythm sometimes with signs of paroxysmal activity and interhemispheric asymmetry or low-amplitude EEG. It is estimated that reliable positive changes in amplitude-time characteristics of multimodal evoked potentials, reliable decrease of motor thresholds mostly in left hemisphere and increase of motor evoked potentials amplitude are in 5-7 preceded by clinical improvement in patients with TBI.