Functional MRI and Outcome in Traumatic Coma
- 486 Downloads
Advances in task-based functional MRI (fMRI), resting-state fMRI (rs-fMRI), and arterial spin labeling (ASL) perfusion MRI have occurred at a rapid pace in recent years. These techniques for measuring brain function have great potential to improve the accuracy of prognostication for civilian and military patients with traumatic coma. In addition, fMRI, rs-fMRI, and ASL perfusion MRI have provided novel insights into the pathophysiology of traumatic disorders of consciousness, as well as the mechanisms of recovery from coma. However, functional neuroimaging techniques have yet to achieve widespread clinical use as prognostic tests for patients with traumatic coma. Rather, a broad spectrum of methodological hurdles currently limits the feasibility of clinical implementation. In this review, we discuss the basic principles of fMRI, rs-fMRI, and ASL perfusion MRI and their potential applications as prognostic tools for patients with traumatic coma. We also discuss future strategies for overcoming the current barriers to clinical implementation.
KeywordsTraumatic brain injury Traumatic axonal injury Coma Functional MRI Resting-state functional MRI Arterial spin labeling perfusion MRI Default mode network Traumatic coma
The contents of this article were developed with support from the National Institutes of Health (R25NS065743), the Center for Integration of Medicine and Innovative Technology (Boston, MA, USA), and the National Institute on Disability and Rehabilitation Research, United States Department of Education (H133A120085; Spaulding–Harvard Traumatic Brain Injury Model System). However, the contents do not necessarily represent the policy of the Department of Education, and endorsement by the federal government should not be assumed.
Compliance with Ethics Guidelines
Conflict of Interest
Brian L. Edlow and Ona Wu declare that they have no conflict of interest.
Joseph T. Giacino has been a consultant for Craig Rehabilitation Hospital and Frazier Rehabilitation Hospital, has served as an expert witness consultant on five legal cases in the last 36 months involving patients with disorders of consciousness concerning diagnosis, prognosis, pain and suffering, and adequacy of treatment, and has received grant support from the James S. McDonnell Foundation.
Human and Animal Rights and Informed Consent
This article contains imaging data from a human subject that were acquired as part of a study approved by our hospital's Institutional Review Board. Informed consent for the study was provided by the subject's legal guardian.
Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance
- 2.Faul M, Xu L, Wald MM, et al. Traumatic brain injury in the United States: emergency department visits, hospitalizations, and deaths. Atlanta: Centers for Disease Control and Prevention, National Center for Injury Prevention and Control; 2010.Google Scholar
- 9.Zoroya G. For troops with brain trauma, a long journey back. Tampa: USA Today; 2010. http://usatoday30.usatoday.com/news/military/2010-07-29-1Aawakening29_CV_N.htm
- 20.Edlow BL, Wu O. Advanced neuroimaging in traumatic brain injury. Semin Neurol. 2012;32:372–98.Google Scholar
- 33.Donaldson DI, Buckner RL. Effective paradigm design. In: Jezzard P, Matthews PM, Smith SM, editors. Functional MRI: an introduction to methods. Oxford: Oxford University Press; 2001.Google Scholar
- 40.• Coleman MR, Davis MH, Rodd JM, et al. Towards the routine use of brain imaging to aid the clinical diagnosis of disorders of consciousness. Brain. 2009;132:2541–52. In this fMRI study of 41 patients in a VS (n = 22) and an MCS (n = 19), a passive language stimulus was used to investigate language networks. Hierarchical language-related fMRI activation patterns correlated with the degree of behavioral recovery 6 months after the fMRI scan.PubMedCrossRefGoogle Scholar
- 53.•• Monti MM, Vanhaudenhuyse A, Coleman MR, et al. Willful modulation of brain activity in disorders of consciousness. N Engl J Med. 2010;362:579–89. This study includes the largest cohort of patients with DOC to be assessed with spatial and motor imagery fMRI paradigms (n = 54). Five of 54 patients (all with TBI) had patterns of brain activation during the command-following paradigms that were similar to those of controls, and one patient in an MCS could link the two imagery tasks to “yes” and “no” answers.PubMedCrossRefGoogle Scholar
- 76.• Vanhaudenhuyse A, Noirhomme Q, Tshibanda LJ, et al. Default network connectivity reflects the level of consciousness in non-communicative brain-damaged patients. Brain. 2010;133:161–71. In this rs-fMRI study of patients in a coma (n = 5), in a VS (n = 4), in an MCS (n = 4), and with locked-in syndrome (n = 1), the strength of functional connectivity within the DMN correlated linearly with the level of consciousness.PubMedCrossRefGoogle Scholar
- 87.• Liu AA, Voss HU, Dyke JP, et al. Arterial spin labeling and altered cerebral blood flow patterns in the minimally conscious state. Neurology. 2011;77:1518–23. In this ASL perfusion MRI study of patients in a traumatic MCS, CBF was preserved in the precuneus/posterior cingulate region but was decreased in the anterior nodes of the DMN (e.g., medial prefrontal cortex).PubMedCrossRefGoogle Scholar