Mechanisms of Photophobia in Mild Traumatic Brain Injury in Human Subjects: Therapeutic Implications
Annual rept. 30 Sep 2014-29 Sep 2015
SMITH-KETTLEWELL EYE RESEARCH INST SAN FRANCISCO CA
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The objective of the project is the investigation of two proposed mechanisms of mTBI-related photophobia 1 that mRGC damage is a primary mechanism in photophobia and 2 that mTBI-induced edema can be the causal mechanism of photophobia. The project uses ERG Aim 1, high-density EEG Aim 2, functional MRI Aim 3, and tensor-based morphometric MRI Aim 4 to assess the respective contributions of these mechanisms of photophobia in humans with mTBI, providing biomarkers for the involvement of these mechanisms. The goal for the present period was to complete the analysis techniques for all four Aims and begin testing the photophobic and non-photophobic participants. For Aim 1, a novel approach of recording ERGs through the EGI net was validated and the latency and amplitude assessment technique for each color condition developed. For Aim 2, a component analysis for the high-density EEG was developed and shown to elicit responses with the predicted mRGC-specific spectral characteristics. In Aim 3, the fMRI techniques for determining subcortical brain structures activated by mRGC-specific stimuli were validated. In Aim 4, the tensor-based morphometry methodology was developed to assess brain tissue edema or shrinkage relative to controls. The testing of participants on all four modalities is on schedule.
- Anatomy and Physiology
- Medicine and Medical Research