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Correspondence: When an article is eligible for submission of Correspondence, a link to the response form is available within the full-text article. You must be a current subscriber who has activated the online portion of your subscription in order to send a Correspondence. Any reader can read published Correspondence.
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Correspondence:Correspondence published:
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fMRI reveals large-scale network activation in minimally conscious patients
- Chad H. Moritz (3 May 2005)
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fMRI reveals large-scale network activation in minimally conscious patients
- Stephen L. Black (3 May 2005)
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Chad H. Moritz, University of Wisconsin-Madison Medical School E1/311 CSC, 600 Highland Avenue, Madison, WI 53792-3252
Send Correspondence to journal:
ch.moritz{at}hosp.wisc.edu Chad H. Moritz
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We read Schiff et al's article with great interest. We conducted a case study regarding the application of fMRI to a patient in a minimally conscious state. [1] The Schiff et al article appears to corroborate our findings of multi-sensory and cognitive fMRI BOLD responses in an overtly unresponsive brain injured patient. These initial reports probing the minimally conscious state with imaging methods offer intriguing possibilities, and indeed the 2001 fMRI case study closely correlated with the patient's eventual recovery. Further research in this area is warranted. Reference 1. Moritz CH, Rowley HA, Haughton VM, Swartz KR, Jones J, and Badie B. Functional MR imaging assessment of a non-responsive brain injured patient. Magnetic Resonance Imaging 2001; 19: 1129-32. |
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Stephen L. Black, Bishop's University Lennoxville, Quebec J1M 1Z7, CANADA
Send Correspondence to journal:
sblack{at}ubishops.ca Stephen L. Black
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Schiff et al [1] reported that two severely brain-injured patients monitored with fMRI showed brain responses to auditory “personal narratives” but not when the input was presented in reverse, meaningless form. A similar study [2] with equally-remarkable results was carried out more than 20 years earlier, ironically also by researchers at Columbia University. That it was overlooked by Schiff et al is an indication of the obscurity into which this study has undeservedly fallen. In the earlier report of Boyle and Greer, three brain-injured patients with disabilities at least as severe as those in the Schiff et al study were studied. In place of monitoring by fMRI, operant conditioning was used to increase small spontaneous responses made by each patient including eyelid, finger, or mouth movements. The reinforcer in each case was the playing of a 15-second sample of music identified as the patient’s favorite, presented contingent on an occurrence of the target response. A multiple-baseline design with reversal, [3] a technique of the field of applied behavior analysis, was used to assess causal relationships. The authors reported good evidence of learning for the first patient, lesser but suggestive evidence for the second, and little evidence of learning for the third. The first patient subsequently recovered from the vegetative state to a limited extent, the second did not recover, and the third died within one week after the end of testing. Thus successful operant conditioning may possibly predict recovery and may even help produce it. Schiff et al concluded in their later study that their findings of changes in brain activity in response to meaningful auditory input “raise important questions related to whether MCS [minimally conscious state] patients have a greater capacity to experience subjective states but also to benefit from therapeutic intervention”. The results of the Boyle and Greer study raise the same questions, but go one step further by showing an actual change in behavior in response to reinforcement by emotionally-meaningful stimuli. Although the methods differ, the results of the two studies complement each other. Both methods should be exploited as valuable tools towards the goals of understanding and enhancing the capabilities of the brain-injured, minimally conscious patient. References 1. Schiff ND, Rodriguez-Moreno D, Kamal A, et al. fMRI reveals large- scale network activation in minimally conscious patients. Neurology 2005; 64: 514-523. 2. Boyle ME, Greer, RD. Operant procedures and the comatose patient. J Appl Beh Anal 1983; 16: 3-12. 3. Kazdin, A. Behavior modification in applied settings, 6th ed. Belmont, CA: Wadsworth, 2001. Conflict of interest: none The authors had the opportunity to respond to these Correspondences but declined. |
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