Bilateral population receptive fields in congenital hemihydranencephaly.
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.



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.



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.



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.
Department of Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, The Netherlands.|Department of Radiology, Imaging Division, University Medical Centre, Utrecht, The Netherlands.|Spinoza Centre for Neuroimaging, Amsterdam, The Netherlands.
Alessio
A
Fracasso
Department of Ophthalmology, University Medical Centre Utrecht, Utrecht, The Netherlands.
Yvonne
Y
Koenraads
Department of Ophthalmology, University Medical Centre Utrecht, Utrecht, The Netherlands.
Giorgio L
GL
Porro
Department of Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, The Netherlands.|Spinoza Centre for Neuroimaging, Amsterdam, The Netherlands.
Serge O
SO
Dumoulin
D000328:Adult; D005133:Eye Movements / Q000502:physiology; D006801:Humans; D006832:Hydranencephaly / Q000175:diagnosis / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010775:Photic Stimulation; D014793:Visual Cortex / Q000000981:diagnostic imaging / Q000503:physiopathology*; D014794:Visual Fields / Q000502:physiology*
functional MRI; hemihydranencephaly; modelling; plasticity; population receptive field; stability