Use of the Photo-Electromyogram to Objectively Diagnose and Monitor Treatment of Post-TBI Light Sensitivity
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 one): 1) optimization of hardware and software interfaces for recording of the electromyogram (EMG) elicited by light, 2) development of software to simultaneously record and analyze light evoked changes in the EMG, skin conductance, heart rate, and pupil responses. 3) EMG recording from chronically implanted electrodes in the mouse orbicularis muscle was developed using the DSI wireless system of data transmission of biopotentials). 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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2012
- Accession Number
- ADA602414
Entities
People
- Andrew F Russo
- Pieter Poolman
- Randy H. Kardon
Organizations
- University of Iowa