Objective: To investigate the cerebral metabolic and functional patterns during recovery from cortical blindness.
Design: Follow-up study with serial clinical, metabolic, and functional imaging and visual evoked potentials.
Case presentation: A 24-year-old woman suffered from cortical blindness after cardiac arrest and recovered over a 6-month period. During recovery, she experienced complex visual hallucinations that could be initiated by visual imagery.
Results: Initially, the regional cerebral metabolic rate of glucose was severely reduced in the visual and parieto-occipital cortex bilaterally but recovered almost completely. Visual hallucinations led to significant increases of the regional cerebral blood flow in the initially severely hypometabolic parieto-occipital and temporo-lateral cortex.
Conclusions: Recovery of vision was related to normalization of the postlesionally dysfunctional cortex. Visual hallucinations appeared as the clinical correlate of the electrophysiological hyperexcitability of the recovering partially damaged visual cortex.