RT Journal Article
T1 Transition from the locked in to the completely locked-in state: 												A physiological analysis
A1 Murguialday, A. Ramos
A1 Hill, J.
A1 Bensch, M.
A1 Martens, S.
A1 Halder, S.
A1 Nijboer, F.
A1 Schoelkopf, B.
A1 Birbaumer, N.
A1 Gharabaghi, A.
AB Objective: To clarify the physiological and behavioral boundaries between locked-in (LIS) and the completely locked-in state (CLIS) (no voluntary eye movements, no communication possible) through electrophysiological data and to secure brain-computer-interface (BCI) communication. Methods: Electromyography from facial muscles, external anal sphincter (EAS), electrooculography and electrocorticographic data during different psychophysiological tests were acquired to define electrophysiological differences in an amyotrophic lateral sclerosis (ALS) patient with an intracranially implanted grid of 112 electrodes for nine months while the patient passed from the LIS to the CLIS. Results: At the very end of the LIS there was no facial muscle activity, nor external anal sphincter but eye control. Eye movements were slow and lasted for short periods only. During CLIS event related brain potentials (ERP) to passive limb movements and auditory stimuli were recorded, vibrotactile stimulation of different body parts resulted in no ERP response. Conclusions: The results presented contradict the commonly accepted assumption that the EAS is the last remaining muscle under voluntary control and demonstrate complete loss of eye movements in CLIS. The eye muscle was shown to be the last muscle group under voluntary control. The findings suggest ALS as a multisystem disorder, even affecting afferent sensory pathways. Significance: Auditory and proprioceptive brain-computer-interface (BCI) systems are the only remaining communication channels in CLIS.
SN 1388-2457
YR 2011
FD 2011-05
LK https://hdl.handle.net/11556/3751
UL https://hdl.handle.net/11556/3751
LA eng
NO Murguialday , A R , Hill , J , Bensch , M , Martens , S , Halder , S , Nijboer , F , Schoelkopf , B , Birbaumer , N & Gharabaghi , A 2011 , ' Transition from the locked in to the completely locked-in state : A physiological analysis ' , Clinical Neurophysiology , vol. 122 , no. 5 , pp. 925-933 . https://doi.org/10.1016/j.clinph.2010.08.019
NO The authors thank Christian Puzicha for his help performing the experiments. The authors thank Dr. Enck for his assistance with the external anal sphincter experiments. Funding was provided by the Deutsche Forschungsgemeinschaft ( DFG GH 94/2-1 , DFG EC 307 BI 195 ), The ERC grant 227632-BCCI and the German Ministry of Education and Research (Bernstein Centers 01GQ0831 and 01GQ0761 , BMBF 16SV3783 ).
DS TECNALIA Publications
RD 26 jul 2024