Dr. Brenda Hanna-Pladdy is a clinical neuropsychologist and Assistant Professor in the Landon Center on Aging and Department of Psychiatry at the University of Kansas Medical Center (KUMC). The purpose of this proposal is to foster the scientific development in stroke recovery mechanisms and fMRI skills of the candidate, so that she may become an independent clinical scientist. The Landon Center on Aging and the Hoglund Brain Imaging Center at KUMC will provide the candidate with the ideal setting to investigate the neural mechanisms subserving skilled movements and the recovery of apraxia following stroke. The long-term objective of this research plan is to explore the multisensory nature of movement representations in the praxis system in order to identify rehabilitation targets. Ideomotor apraxia (IMA) is a skilled movement disorder that is common after left hemisphere (LH) stroke, and may contribute to significant disability in the everyday environment. The collaboration with the primary mentor (Dr. Nudo) will allow the candidate to obtain the foundation for the development of an independent academic career by expanding the candidate's scientific background in stroke recovery and neuroplasticity, and promoting her research and grantsmanship skills. The co-mentors will provide mentorship in fMRI techniques and lesion-symptom mapping in stroke (Dr. Savage), and neuroanatomical and clinical aspects of skilled movement disorders (Dr. Haaland). The proposed study will utilize an event-related fMRI study designed to distinguish regions involved in retrieving the spatiotemporal features of familiar tools/objects (without actual movement) when elicited by auditory, visual and multisensory cues. These activation patterns will be correlated to a behavioral paradigm measuring the quality of movement trajectories in LH stroke patients (with and without apraxia) and normal controls to determine if the addition of auditory motion cues to visual cues (i.e., multisensory cues) may provide better access to movement representations.
The aims are the following (i) to characterize how sensory cues facilitate the retrieval of object action features, (ii) to elucidate the neural substrates of praxis and the multisensory nature of movement representations, and (iii) to evaluate functional adaptation in audiovisual movement representations following LH stroke. This data will elucidate the functional and anatomical basis for apraxia, and help identify appropriate sensory cues for rehabilitation of limb apraxia following stroke.
This research will have broad impact on public health, as stroke is a leading cause of long-term disability, and leaves many of its victims unable to function independently in the environment without assistance leading to substantial social and fiscal costs. IMA is a disorder common after LH stroke that directly affects effective manipulation of objects in the environment, and has demonstrated impact on independence. Thus, development of a rehabilitation program for IMA will significantly improve functional independence and quality of life for stroke survivors.