Accession Number:

ADA621310

Title:

Use of the Photo-Electromyogram to Objectively Diagnose and Monitor Treatment of Post-TBI Light Sensitivity

Descriptive Note:

Annual rept. 6 Sep 2013-5 Sep 2014

Corporate Author:

IOWA UNIV IOWA CITY

Report Date:

2014-10-01

Pagination or Media Count:

23.0

Abstract:

Purpose to test the whether photosensitivity photophobia after traumatic brain injury TBI is due to increased sensitivity of the brainstem trigeminal sensory nucleus, as revealed objectively by an exaggerated photoblink reflex photo-electromyogram. This will be tested in humans and in a mouse strain genetically engineered to be hypersensitive to calcitonin gene related peptide CGRP, the neurotransmitter modulating trigeminal nerve function. Scope objective methods to quantify photo-sensitivity include 1 light evoked potentials electromyogram from the blinking and squinting muscles of the forehead 2 the pupil light reflex 3 light evoked changes in sympathetic nerve activity, measured by changes in skin conductance and heart rate. Major Findings Year 3 1 based on Facial Action Coding System FACS metrics extracted from video recordings, we have shown that videography and image analysis -- for tracking changes in eyelid position and eye brow shape -- can be used as a substitute method for measuring EMG activity unobtrusively, 2 in contrast to earlier results, we have observed an overall decrease in EMG activity after CGRP administration, especially for hRAMP1 transgenic mice. Significance objective testing of photosensitivity in humans and mice will provide new approaches to finding the underlying mechanisms, classification of photosensitivity, diagnosis and monitoring of new treatments.

Subject Categories:

  • Anatomy and Physiology
  • Medicine and Medical Research
  • Stress Physiology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE