Functional Imaging in Stroke Recovery
Functional neuroimaging is a general term for techniques that image brain activity, above and beyond the structural anatomy information that is derived from standard imaging. The functional imaging techniques, which include positron emission tomography (PET), magnetic encephalography (MEG), single photon emission computed tomography (SPECT), and functional magnetic imaging (fMRI) have contributed greatly to our understanding of the mechanisms of recovery. The techniques generally work by having the patient perform a physical or mental task during scanning and then deriving a statistical map of the regional activation that correlates with that task.
The most commonly used signal to demonstrate task-related, focal neuronal activity with fMRI is the blood oxygen level dependent (BOLD) signal, which is generated by the paramagnetic characteristics of increased oxygenated blood flow that follows the increase in local neuronal metabolic activity (Logothetis, 2002). The BOLD...
KeywordsTranscranial Magnetic Stimulation Blood Oxygen Level Dependent Supplementary Motor Area Blood Oxygen Level Dependent Signal Stroke Recovery
- Dijkhuizen, R. M., Ren, J., Mandeville, J. B., Wu, O., Ozdag, F. M., Moskowitz, M. A., et al. (2001). Functional magnetic resonance imaging of reorganization in rat brain after stroke. Proceedings of the National Academy of Sciences of the United States of America, 98(22), 12766–12771.Google Scholar
- Dijkhuizen, R. M., Singhal, A. B., Mandeville, J. B., Wu, O., Halpern, E. F., Finklestein, S. P., et al. (2003). Correlation between brain reorganization, ischemic damage, and neurologic status after transient focal cerebral ischemia in rats: a functional magnetic resonance imaging study. Journal of Neuroscience, 23(2), 510–517.PubMedGoogle Scholar
- Foltys, H., Krings, T., Meister, I. G., Sparing, R., Boroojerdi, B., Thron, A., et al. (2003). Motor representation in patients rapidly recovering after stroke: a functional magnetic resonance imaging and transcranial magnetic stimulation study. Clinical Neurophysiology, 114(12), 2404–2415.PubMedCrossRefGoogle Scholar
- Johansen-Berg, H., Rushworth, M. F., Bogdanovic, M. D., Kischka, U., Wimalaratna, S., & Matthews, P. M. (2002). The role of ipsilateral premotor cortex in hand movement after stroke. Proceedings of the National Academy of Sciences of the United States of America, 99(22), 14518–14523.Google Scholar
- Krakauer, J. W., Zarahn E, Lazar RM, & Marshall RS. (2007). Imaging “Likelihood to Recover” in Acute Stroke. Stroke 38, 520 (abs).Google Scholar
- Marshall, R. S., Krakauer, J. W., Radoeva, P. D., Wydra, J., Lazar, R. M., & Hirsch, J. (2004). Hemispheric hemodynamic impairment in the absence of stroke induces fMRI activation in the opposite hemisphere. Neurology, 62(7), A541.Google Scholar
- Neumann-Haefelin, T., Staiger, J. F., Redecker, C., Zilles, K., Fritschy, J. M., Mohler, H., et al. (1998). Immunohistochemical evidence for dysregulation of the GABAergic system ipsilateral to photochemically induced cortical infarcts in rats. Neuroscience, 87(4), 871–879.PubMedCrossRefGoogle Scholar
- Ogawa, S., Menon, R. S., Tank, D. W., Kim, S. G., Merkle, H., Ellermann, J. M., et al. (1993). Functional brain mapping by blood oxygenation level-dependent contrast magnetic resonance imaging. A comparison of signal characteristics with a biophysical model. Biophys J, 64(3), 803–812.PubMedCrossRefGoogle Scholar
- Rutten, G. J., Ramsey, N. F., van Rijen, P. C., Franssen, H., & van Veelen, C. W. (2002). Interhemispheric reorganization of motor hand function to the primary motor cortex predicted with functional magnetic resonance imaging and transcranial magnetic stimulation. Journal of Child Neurology, 17(4), 292–297.PubMedCrossRefGoogle Scholar
- Ward, N. S., Brown, M. M., Thompson, A. J., & Frackowiak, R. S. (2003a). Neural correlates of motor recovery after stroke: a longitudinal fMRI study. Brain, 126(Pt 11), 2476–2496.Google Scholar
- Ward, N. S., Brown, M. M., Thompson, A. J., & Frackowiak, R. S. (2003b). Neural correlates of outcome after stroke: a cross-sectional fMRI study. Brain, 126(Pt 6), 1430–1448.Google Scholar