TY - JOUR
T1 - Unravelling motor networks in patients with chronic disorders of consciousness
T2 - A promising minimally invasive approach
AU - Naro, Antonino
AU - Leo, Antonino
AU - Buda, Antonio
AU - Manuli, Alfredo
AU - Bramanti, Alessia
AU - Bramanti, Placido
AU - Calabrò, Rocco Salvatore
PY - 2016/9/1
Y1 - 2016/9/1
N2 - Behavioral responsiveness and awareness levels correlate with the degree of functional connectivity within cortical-thalamocortical networks, whose breakdown accounts for chronic disorders of consciousness (DOC). Our study was aimed at assessing the role of the primary motor area (M1) and premotor-M1 circuitry dysfunction in motor output deterioration in minimally conscious state (MCS) and unresponsive wakefulness syndrome (UWS) patients. As a control group, we included a healthy subject (HC) sample in the study. We evaluated the effects of different types of transcranial magnetic stimuli over M1 by recording post-stimulus time histogram (PSTH), which includes a series of peaks of unit firing activity that match with D and I-waves, characterizing the descending corticospinal volleys evoked by transcranial magnetic stimuli. As compared to HC, DOC patients showed a dysfunction of intra-M1 and premotor-M1 circuits, which correlated with the Coma Recovery Scale-Revised scorings. Nonetheless, one UWS patient showed a partially preserved premotor-M1 circuitry, paralleled by a severe intra-M1 circuitry dysfunction. Our data suggest that motor unresponsiveness in some DOC patients may be due to a pure motor output failure, as in the functional locked-in syndrome (fLIS), rather than to a premotor-motor connectivity impairment, which instead characterizes MCS and UWS.
AB - Behavioral responsiveness and awareness levels correlate with the degree of functional connectivity within cortical-thalamocortical networks, whose breakdown accounts for chronic disorders of consciousness (DOC). Our study was aimed at assessing the role of the primary motor area (M1) and premotor-M1 circuitry dysfunction in motor output deterioration in minimally conscious state (MCS) and unresponsive wakefulness syndrome (UWS) patients. As a control group, we included a healthy subject (HC) sample in the study. We evaluated the effects of different types of transcranial magnetic stimuli over M1 by recording post-stimulus time histogram (PSTH), which includes a series of peaks of unit firing activity that match with D and I-waves, characterizing the descending corticospinal volleys evoked by transcranial magnetic stimuli. As compared to HC, DOC patients showed a dysfunction of intra-M1 and premotor-M1 circuits, which correlated with the Coma Recovery Scale-Revised scorings. Nonetheless, one UWS patient showed a partially preserved premotor-M1 circuitry, paralleled by a severe intra-M1 circuitry dysfunction. Our data suggest that motor unresponsiveness in some DOC patients may be due to a pure motor output failure, as in the functional locked-in syndrome (fLIS), rather than to a premotor-motor connectivity impairment, which instead characterizes MCS and UWS.
KW - Corticospinal tract
KW - Descending volleys
KW - MCS
KW - TMS
KW - UWS
UR - http://www.scopus.com/inward/record.url?scp=84975140944&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84975140944&partnerID=8YFLogxK
U2 - 10.1016/j.brainres.2016.06.012
DO - 10.1016/j.brainres.2016.06.012
M3 - Article
AN - SCOPUS:84975140944
VL - 1646
SP - 262
EP - 268
JO - Brain Research
JF - Brain Research
SN - 0006-8993
ER -