Brain plasticity in fMRI and DTI

Abstract

This chapter describes what kind of neuroplastic information may be generated by functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) after brain damage. Clinical neuroplasticity may be defined as an active reorganization contrary to loss of activation or connectivity simply due to brain damage. After giving an overview about general aspects of clinical neuroplasticity, this chapter introduces specific benefits of neuroplasticity investigations for patient care. These include better definition of the patients’ functional state, better individual prognosis, improvement of treatment strategies, and progress in understanding how the nervous system acts in response to disease. Since fMRI and DTI are restricted to detecting neuroplastic changes on the level of neuronal populations and their connections, some important molecular and cellular mechanisms driving these effects are also discussed. Further, a review is given about previously described neuroplastic responses of the diseased brain. This focuses on neuroplasticity evoked by pathomorphological changes of a previously healthy nervous system. It allows an illustration of the complexity and limitations of neuroplasticity research. To ease a critical evaluation of published data, this chapter also includes methodological considerations, which deal with the limitations of the technical or neurophysiological interpretation of neuro-plasticity investigations. Finally, some clinical examples illustrating the potential of fMRI and DTI are given.