Down-regulation of early visual cortex excitability mediates oscillopsia suppression.

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Down-regulation of early visual cortex excitability mediates oscillopsia suppression. / Ahmad, Hena ; Roberts, Ed; Patel, Mitesh et al.
Yn: Neurology, Cyfrol 89, Rhif 11, 16.08.2017.

Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

HarvardHarvard

Ahmad, H, Roberts, E, Patel, M, Lobo, R, Seemungal , B, Arshad, Q & Bronstein, AM 2017, 'Down-regulation of early visual cortex excitability mediates oscillopsia suppression.', Neurology, cyfrol. 89, rhif 11.

APA

Ahmad, H., Roberts, E., Patel, M., Lobo, R., Seemungal , B., Arshad, Q., & Bronstein, A. M. (2017). Down-regulation of early visual cortex excitability mediates oscillopsia suppression. Neurology, 89(11).

CBE

Ahmad H, Roberts E, Patel M, Lobo R, Seemungal B, Arshad Q, Bronstein AM. 2017. Down-regulation of early visual cortex excitability mediates oscillopsia suppression. Neurology. 89(11).

MLA

VancouverVancouver

Ahmad H, Roberts E, Patel M, Lobo R, Seemungal B, Arshad Q et al. Down-regulation of early visual cortex excitability mediates oscillopsia suppression. Neurology. 2017 Awst 16;89(11).

Author

Ahmad, Hena ; Roberts, Ed ; Patel, Mitesh et al. / Down-regulation of early visual cortex excitability mediates oscillopsia suppression. Yn: Neurology. 2017 ; Cyfrol 89, Rhif 11.

RIS

TY - JOUR

T1 - Down-regulation of early visual cortex excitability mediates oscillopsia suppression.

AU - Ahmad, Hena

AU - Roberts, Ed

AU - Patel, Mitesh

AU - Lobo, Rhannon

AU - Seemungal , Barry

AU - Arshad, Qadeer

AU - Bronstein, Adolfo M

PY - 2017/8/16

Y1 - 2017/8/16

N2 - Objective: To identify in an observational study the neurophysiologic mechanisms that mediate adaptation to oscillopsia in patients with bilateral vestibular failure (BVF). Methods: We directly probe the hypothesis that adaptive changes that mediate oscillopsia suppression implicate the early visual-cortex (V1/V2). Accordingly, we investigated V1/V2 excitability using transcranial magnetic stimulation (TMS) in 12 avestibular patients and 12 healthy controls. Specifically, we assessed TMS-induced phosphene thresholds at baseline and cortical excitability changes while performing a visual motion adaptation paradigm during the following conditions: baseline measures (i.e., static), during visual motion (i.e., motion before adaptation), and during visual motion after 5 minutes of unidirectional visual motion adaptation (i.e., motion adapted). Results: Patients had significantly higher baseline phosphene thresholds, reflecting an underlying adaptive mechanism. Individual thresholds were correlated with oscillopsia symptom load. During the visual motion adaptation condition, no differences in excitability at baseline were observed, but during both the motion before adaptation and motion adapted conditions, we observed significantly attenuated cortical excitability in patients. Again, this attenuation in excitability was stronger in less symptomatic patients. Conclusions: Our findings provide neurophysiologic evidence that cortically mediated adaptive mechanisms in V1/V2 play a critical role in suppressing oscillopsia in patients with BVF.

AB - Objective: To identify in an observational study the neurophysiologic mechanisms that mediate adaptation to oscillopsia in patients with bilateral vestibular failure (BVF). Methods: We directly probe the hypothesis that adaptive changes that mediate oscillopsia suppression implicate the early visual-cortex (V1/V2). Accordingly, we investigated V1/V2 excitability using transcranial magnetic stimulation (TMS) in 12 avestibular patients and 12 healthy controls. Specifically, we assessed TMS-induced phosphene thresholds at baseline and cortical excitability changes while performing a visual motion adaptation paradigm during the following conditions: baseline measures (i.e., static), during visual motion (i.e., motion before adaptation), and during visual motion after 5 minutes of unidirectional visual motion adaptation (i.e., motion adapted). Results: Patients had significantly higher baseline phosphene thresholds, reflecting an underlying adaptive mechanism. Individual thresholds were correlated with oscillopsia symptom load. During the visual motion adaptation condition, no differences in excitability at baseline were observed, but during both the motion before adaptation and motion adapted conditions, we observed significantly attenuated cortical excitability in patients. Again, this attenuation in excitability was stronger in less symptomatic patients. Conclusions: Our findings provide neurophysiologic evidence that cortically mediated adaptive mechanisms in V1/V2 play a critical role in suppressing oscillopsia in patients with BVF.

M3 - Article

VL - 89

JO - Neurology

JF - Neurology

SN - 0028-3878

IS - 11

ER -