Bilateral population receptive fields in congenital hemihydranencephaly: Ophthalmic and Physiological Optics

TY - JOUR

T1 - Bilateral population receptive fields in congenital hemihydranencephaly

T2 - Ophthalmic and Physiological Optics

AU - Fracasso, A.

AU - Koenraads, Y.

AU - Porro, G. L.

AU - Dumoulin, Serge O.

PY - 2016/4/25

Y1 - 2016/4/25

N2 - Purpose: Congenital hemihydranencephaly (HH) is a very rare disorder characterised by prenatal near-complete unilateral loss of the cerebral cortex. We investigated a patient affected by congenital right HH whose visual field extended significantly into the both visual hemifields, suggesting a reorganisation of the remaining left visual hemisphere. We examined the early visual cortex reorganisation using functional MRI (7T) and population receptive field (pRF) modelling. Methods: Data were acquired by means of a 7T MRI while the patient affected by HH viewed conventional population receptive field mapping stimuli. Two possible pRF reorganisation schemes were evaluated: where every cortical location processed information from either (i) a single region of the visual field or (ii) from two bilateral regions of the visual field. Results: In the patient affected by HH, bilateral pRFs in single cortical locations of the remaining hemisphere were found. In addition, using this specific pRF reorganisation scheme, the biologically known relationship between pRF size and eccentricity was found. Conclusions: Bilateral pRFs were found in the remaining left hemisphere of the patient affected by HH, indicating reorganisation of intra-cortical wiring of the early visual cortex and confirming brain plasticity and reorganisation after an early cerebral damage in humans.

AB - Purpose: Congenital hemihydranencephaly (HH) is a very rare disorder characterised by prenatal near-complete unilateral loss of the cerebral cortex. We investigated a patient affected by congenital right HH whose visual field extended significantly into the both visual hemifields, suggesting a reorganisation of the remaining left visual hemisphere. We examined the early visual cortex reorganisation using functional MRI (7T) and population receptive field (pRF) modelling. Methods: Data were acquired by means of a 7T MRI while the patient affected by HH viewed conventional population receptive field mapping stimuli. Two possible pRF reorganisation schemes were evaluated: where every cortical location processed information from either (i) a single region of the visual field or (ii) from two bilateral regions of the visual field. Results: In the patient affected by HH, bilateral pRFs in single cortical locations of the remaining hemisphere were found. In addition, using this specific pRF reorganisation scheme, the biologically known relationship between pRF size and eccentricity was found. Conclusions: Bilateral pRFs were found in the remaining left hemisphere of the patient affected by HH, indicating reorganisation of intra-cortical wiring of the early visual cortex and confirming brain plasticity and reorganisation after an early cerebral damage in humans.

KW - functional MRI hemihydranencephaly modelling plasticity population receptive field stability human visual-cortex macaque monkey projection tomography extrastriate cortex cebus monkey representation maps fmri topography plasticity

U2 - 10.1111/opo.12294

DO - 10.1111/opo.12294

M3 - Article

SN - 0275-5408

VL - 36

SP - 324

EP - 334

JO - Ophthalmic and Physiological Optics

JF - Ophthalmic and Physiological Optics

IS - 3

ER -