Graduation Semester and Year

2008

Language

English

Document Type

Thesis

Degree Name

Master of Science in Biomedical Engineering

Department

Bioengineering

First Advisor

Georgios Alexandrakis

Abstract

In recent years the National Institutes of Health has placed great emphasis on addressing the emergent need to accelerate translation of laboratory discoveries into clinical practice. The proposed study is very much aligned with this NIH emphasis, targeting on the translation of near infrared (NIR) brain imaging to clinical assessment for children with cerebral palsy. Over ten million Americans are affected by central nervous system disorders that result in motor deficits. Cerebral palsy (CP) is the most common motor disorder of central origin in childhood and affects at least 2 children per 1000 live births every year . One of the most prevalent types of cerebral palsy is hemiparetic CP, an incomplete paralysis of one half of the body. These motor deficits profoundly affect a child's ability to develop age-typical motor skills and to engage fully in play, exploration and self-help activities. Cortical reorganization or neuroplasticity results from adapting to abnormal development, disease, injury, or learning. Changes in neuronal network micro-circuitry in turn affect gross synaptic currents, the spread of neural activation, and the morphology of local field potentials that are concomitant with a particular function. It has been suggested that evaluation of brain activity in patients with CP can be used as a diagnostic tool to test: (a) the functional activation of motor areas, (b) the recovery or change in brain activity over time, and (c) the response of brain activity to a particular treatment. Available neuroimaging techniques in general are useful to study neuroplastic rearrangements in the human brain in vivo. These techniques include measurements of the regional cerebral blood flow (rCBF), regional cerebral metabolism of glucose or oxygen, and of neuroreceptor and neurotransmitter systems by positron emission tomography (PET). Importantly, functional magnetic resonance imaging (fMRI) has mapped cerebral structures that participate in movement, sensation, or cognitive problem solving. Unfortunately, accurate imaging from these techniques requires the patients' complete body confinement, steadiness and minimal noise for a period of 30-40 minutes. The practical challenges of fulfilling such requirements in children results in a success rate of less than 50% in normal children and are extremely difficult to perform in those with motor disorders, particularly for children with CP. Therefore, advanced, image acquisition and analysis technologies are necessary to non-invasively image or map in vivo changes in brain activities that relate to complex movement. In recent years, functional near infrared spectroscopy (fNIRS) has been increasingly utilized to investigate neural activities in the human brain during a variety of functional stimulations. This technology measures detectable changes in oxygenated (HbO), de-oxygenated (HbR), and total (HbT) hemoglobin concentrations in the cerebral cortex, thereby providing an indirect measurement of the changes in cerebral neuronal activity as they closely correlate with changes in cortical oxygen exchange. Various studies have demonstrated that fNIRS is a sensitive method to detect and map functional activities from the human motor cortex. I hypothesize that appropriate image analysis of fNIRS Images can lead to deciphering the neuronal activation patterns that could be useful for differentiating cerebral palsy kids from control group. Accordingly, my specific aim is: to study various image based metrics in cerebral palsy affected kids and control group, and come up with the metrics that are useful in differentiating cerebral palsy kids from normal subjects.

Disciplines

Biomedical Engineering and Bioengineering | Engineering

Comments

Degree granted by The University of Texas at Arlington

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