It has already been demonstrated that mentalimagining of the complex motor act, such as limblifting, can evoke the activation of the involvedmotor centres even if it doesn’t result inmovement due to paresis.
This finding gives us apossibility to create a new diagnostic model forthe differential diagnostics between the vegetativestate (VS) and the minimally conscious state(MCS). If we could get from patient the efferentmotor response after a verbal command, his levelof conscious should not be defined less than theMCS. To confirm this hypothesis we have usedthe Navigated Brain Stimulation (NSB) toregister the excitation of the motor centres. Thismethod, compared with fMRI, uses the data ofthe electromyography and doesn’t need the actualmovements.Materials & methods: Three patients with thediagnosis of the VS have been included in our studyso far.
All patients demonstrated Level1(ColemanMR, 2007) response to auditorystimulus ‘raise your hand’ and ‘raise your leg’during the fMRI. Were performed the standardNBS motor mapping using the Eximia TMSstimulator, Nexstim Ltd., Finland. (Weredetermined the site of the maximum response forarm and leg.) Then verbal commands were givento every patient.ResultsPatNo Lat?nce Amplitude Tensionbefore after before after before afterAbducensbrevispol.
124,1 23,7 0,69 1,02 163,3 167,0223,4 22,9 3,93 4,24 66,0 70,3326,0 25,0 0,19 0,24 100,0 109,3Peroneuslongus1 32,0 30,8 0,30 0,56 175,3 182,72 31,6 31,7 0,57 0,45 98,3 109,73 38,6 35,6 0,18 0,52 219,7 240,0Using the diagnostic model with the verbalcommands we observed the activation of theinvolved motor centres of the both limbs. Allthree patients during 6 months of the follow-upperiod regained consciousness.Conclusions. Using the NBS we can diagnose ifthe patient in unresponsive state is still capable toform the motor imagery. Such result may be usedas the paraclinical sign of the MCS