Progression from Vegetative to Minimally Conscious State Is Associated with Changes in Brain Neural Response to Passive Tasks: A Longitudinal Single-Case Functional MRI Study.
Functional magnetic resonance imaging (fMRI) may be adopted as a complementary tool for bedside observation in the disorders of consciousness (DOC). However, the diagnostic value of this technique is still debated because of the lack of accuracy in determining levels of consciousness within a single patient. Recently, Giacino and colleagues (2014) hypothesized that a longitudinal fMRI evaluation may provide a more informative assessment in the detection of residual awareness. The aim of this study was to measure the correspondence between clinically defined level of awareness and neural responses within a single DOC patient.



We used a follow-up fMRI design in combination with a passive speech-processing task. Patient's consciousness was measured through time by using the Coma Recovery Scale.



The patient progressed from a vegetative state (VS) to a minimally conscious state (MCS). Patient's task-related neural responses mirrored the clinical change from a VS to an MCS. Specifically, while in an MCS, but not a VS, the patient showed a selective recruitment of the left angular gyrus when he listened to a native speech narrative, as compared to the reverse presentation of the same stimulus. Furthermore, the patient showed an increased response in the language-related brain network and a greater deactivation in the default mode network following his progression to an MCS.



Our findings indicate that longitudinal assessment of brain responses to passive stimuli can contribute to the definition of the clinical status in individual patients with DOC and represents an adequate counterpart of the bedside assessment during the diagnostic decision-making process. (JINS, 2016, 22, 620-630).
1Unità Gravi Cerebrolesioni Acquisite,Auxilium Vitae Volterra,Pisa,Italy.
Francesco
F
Tomaiuolo
1Unità Gravi Cerebrolesioni Acquisite,Auxilium Vitae Volterra,Pisa,Italy.
Luca
L
Cecchetti
4The Brain and Mind Institute,Department of Psychology,University of Western Ontario,London,N6A 5B7,Canada.
Raechelle M
RM
Gibson
1Unità Gravi Cerebrolesioni Acquisite,Auxilium Vitae Volterra,Pisa,Italy.
Fiammetta
F
Logi
4The Brain and Mind Institute,Department of Psychology,University of Western Ontario,London,N6A 5B7,Canada.
Adrian M
AM
Owen
5U.O. Radiologia,ASL5 Volterra,Pisa,Italy.
Franco
F
Malasoma
5U.O. Radiologia,ASL5 Volterra,Pisa,Italy.
Sabino
S
Cozza
2Clinical Psychology Branch,Pisa University Hospital,Pisa,Italy.
Pietro
P
Pietrini
3Laboratory of Clinical Biochemistry and Molecular Biology,Department of Surgical,Medical and Molecular Pathology and Critical Care,University of Pisa,Pisa,Italy.
Emiliano
E
Ricciardi
D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D018458:Persistent Vegetative State / Q000000981:diagnostic imaging / Q000503:physiopathology*; D013067:Speech Perception / Q000502:physiology*; D055815:Young Adult
Disorders of consciousness; Language processing; Longitudinal design; Minimally conscious state; Vegetative state; fMRI