Potential clinical applications for spinal functional MRI

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Current Pain and Headache Reports (Impact Factor: 2.26). 07/2007; 11(3):165-70. DOI: 10.1007/s11916-007-0186-4
Source: PubMed


Functional MRI (fMRI) of the spinal cord is a noninvasive technique for obtaining information regarding spinal cord neuronal function. This article provides a brief overview of recent developments in spinal cord fMRI and outlines potential applications, as well as the limitations that must be overcome, for using spinal fMRI in the clinic. This technique is currently used for research purposes, but significant potential exists for spinal fMRI to become an important clinical tool.

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Available from: Sean Mackey, Aug 11, 2015
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    • "Non-invasive characterization of somatosensory activity in the human spinal cord is important not only for relating human data to those obtained from animal models, but also for providing a framework for investigating spinal cord function in pathological states (Kornelsen and Mackey, 2007), e.g., in multiple sclerosis, spinal cord injuries, and chronic pain. Indeed, pain is an important clinical and social problem (Taylor, 2006; McBeth and Jones, 2007; Smith et al., 2007), often associated with plastic modifications of the spinal cord neural circuitry (Scholz and Woolf, 2007; Cervero, 2009). "
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    ABSTRACT: Recent studies have shown that functional magnetic resonance imaging (fMRI) can non-invasively assess spinal cord activity. Yet, a quantitative description of nociceptive and non-nociceptive responses in the human spinal cord, compared with random signal fluctuations in resting state data, is still lacking. Here we have investigated the intensity and spatial extent of blood oxygenation level dependent (BOLD) fMRI responses in the cervical spinal cord of healthy volunteers, elicited by stimulation of the hand dorsum (C6-C7 dermatomes). In a block design fMRI paradigm, periods (20 s each) of repetitive noxious (laser heat) or innocuous (brushing) stimulation were alternated with rest. To estimate the level of false positive responses, functional images were acquired during a separate run while subjects were at rest. In a first analysis of averaged peristimulus signals from all voxels within each half of the spinal cord, we found bilateral fMRI responses to both stimuli. These responses were significantly larger during noxious than during innocuous stimulation. No significant fMRI signal change was evident over corresponding time periods during the Rest run. In a second, general linear model analysis, we identified a voxel population preferentially responding to noxious stimulation, which extended rostro-caudally over the length (4 cm) of the explored spinal cord region. By contrast, we found no evidence of voxel populations responding uniquely to innocuous stimuli, or showing decreased activity following either kind of somatosensory stimulus. These results provide the first false-positive-controlled comparison of spinal BOLD fMRI responses to noxious and innocuous stimuli in humans, confirming and extending physiological information obtained in other species.
    Full-text · Article · May 2010 · NeuroImage
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    • "Moreover, given the spinal cord changes occurring with time after a lesion, fMRI would allow longitudinal studies in animals with spinal injuries and could help to detect underlying plastic physiological processes leading for instance to locomotor recovery (Frigon and Rossignol, 2006; Rossignol, 2006). Previous studies have shown that fMRI can detect motor (Backes et al., 2001; Giulietti et al., 2008; Govers et al., 2007; Komisaruk et al., 2002; Kornelsen and Stroman, 2004, 2007; Madi et al., 2001; Maieron et al., 2007; Ng et al., 2006; Ng et al., 2008; Stroman and Ryner, 2001; Yoshizawa et al., 1996) and sensory (Brooks et al., 2008; Endo et al., 2008; Lawrence et al., 2004, 2008b; Li et al., 2005; Lilja et al., 2006; Majcher et al., 2006; Malisza and Stroman, 2002; Moffitt et al., 2005; Porszasz et al., 1997; Stroman et al., 2004, 2005a; Zhao et al., 2008) activation in the spinal cord. Although most published studies have used a new type of contrast based on signal enhancement by extravascular protons (SEEP) (Stroman et al., 2003), few studies succeeded in reporting activations in the spinal cord based on blood oxygenation level dependent (BOLD) (Backes et al., 2001; Brooks et al., 2008; Endo et al., 2008; Giove et al., 2004; Giulietti et al., 2008; Govers et al., 2007; Lilja et al., 2006; Madi et al., 2001; Maieron et al., 2007; Stroman et al., 1999; Yoshizawa et al., 1996; Zhao et al., 2008). "
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    ABSTRACT: Functional magnetic resonance imaging (fMRI) of the spinal cord has been the subject of intense research for the last ten years. An important motivation for this technique is its ability to detect non-invasively neuronal activity in the spinal cord related to sensorimotor functions in various conditions, such as after spinal cord lesions. Although promising results of spinal cord fMRI have arisen from previous studies, the poor reproducibility of BOLD activations and their characteristics remain a major drawback. In the present study we investigated the reproducibility of BOLD fMRI in the spinal cord of cats (N=9) by repeating the same stimulation protocol over a long period (approximately 2 h). Cats were anaesthetized with ketamine, and spinal cord activity was induced by electrical stimulation of cutaneous nerves of the hind limbs. As a result, task-related signals were detected in most cats with relatively good spatial specificity. However, BOLD response significantly varied within and between cats. This variability was notably attributed to the moderate intensity of the stimulus producing a low amplitude haemodynamic response, variation in end-tidal CO(2) during the session, low signal-to-noise ratio (SNR) in spinal fMRI time series and animal-specific vascular anatomy. Original contributions of the present study are: (i) first spinal fMRI experiment in ketamine-anaesthetized animals, (ii) extensive study of intra- and inter-subject variability of activation, (iii) characterisation of static and temporal SNR in the spinal cord and (iv) investigation on the impact of CO(2) end-tidal level on the amplitude of BOLD response.
    Full-text · Article · Nov 2008 · NeuroImage
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