Visual activation of extra-striate cortex in the absence of V1 activation

▶ Gray matter of V1 shows abnormal T1 characteristics and its perfusion is reduced. ▶ Damage is confined to gray matter with no adjacent white matter involvement. ▶ BOLD activation levels in the calcarine sulcus are drastically reduced. ▶ Activation of extrastriate regions to visual stimulation is preserved. ▶ Pathway between LGN and V1 shows degeneration; between LGN and V5/MT is intact.