TRANSIENT BLINDNESS ASSOCIATED WITH REVERSIBLE OCCIPITAL WHITE-MATTERABNORMALITIES - 2 PATIENTS STUDIED BY MR, CT, AND 18F-FDG PET IMAGING

Reversible, multifocal hyperintense T2 signal abnormalities were noted within the occipital and posterior parietal subcortical white matter in a previously healthy 59-year-old right-handed woman with acute onse t of cortical blindness and seizures. Repeat brain magnetic resonance imaging and a positron emission tomographic scan of 18F-fluorodeoxyglu cose brain uptake performed 2 months after the ictal event failed to r eveal any abnormality. This patient is similar to a 57-year-old female who developed severe headache and magnetic resonance signal abnormali ties in the subcortical white matter of both occipital lobes, which la ter normalized, as judged by correlative, sequential computed tomograp hic examinations. This study emphasizes that an increasingly more freq uent phenomenon of reversible MRI signal abnormalities can occur withi n the occipital subcortical white matter in acutely ill individuals, a nd not be associated with any lasting abnormalities on clinical examin ation or on radiological imaging studies such as computed tomography, magnetic resonance imaging, or positron emission tomography.