EVS Flashcards
why is stochastic vestibular stimulation used
unpredicable and hard to sandbag for testing
what can EVS do for older adults
can help with balance impairment
what is EVS balance response testing
low intensity current delivered through the skull, stimulating vestibular afferents
patients sway towards the positive electrode
(corrective balance response)
- afferents on the negative side increase firing
- afferents on the positive side decrease firing
what does EVS cause
physical perturbation to balance control through the VSR pathway
what does the direction of EVS evoked balance responses depend on
head position - craniocentric
what is the stochastic resonance effect
where sensitivity to a signal is increased by adding noise
balance is stabilised through noisy subthreshold EVS
what is the relationship between MLR/SLR latency and # of subconcussive sessions
more subconcussive sessions = longer MLR/SLR latency
what is the coherence difference in fighters vs non fighters
fighters = higher response to freqeuncies <5Hz adn lower responses to frequencies >5Hz
(coherence = correlation between EVS adn EMG in frequency domain)
what is the cumulant density difference in fighters vs non fighters
observe later responses in fighters compared to controls
(cumulant density = correlation between EVS and EMG in the time domain)
what is the difference in SVS in fighters vs non fighters
more repetitive head impacts = longer latency in MLR and SLR
does bipolar or monopolar have the higher recruitment threshold
monopolar
(four electrode binaural monopolar = highest response)
which type of sway requires much higher EVS amplitude in order to evoke sway
anterior/posterior sway
