Scotoma perception in white-noise-field campimetry and postchiasmal visual pathway lesions

The authors examined 59 patients (32 women and 27 men) suffering from homonymous hemianopia by white-noise-field campimetry (Tübingen Electronic Campimeter) and by conventional perimetry (Tübingen Automatic Perimeter or Tübingen Manual Perimeter) and by computerized tomography (CT) or magnetic resonance imaging (MR). In all, 56 patients showed neuroradiologically detectable cerebral lesions, which were superimposed in a reconstructed "reference brain". Of these 56 patients, 18 were not capable of perceiving any white-noise-field scotoma, although their conventional perimetric findings showed defects. Lesions of these patients were concentrated along the optic radiation and spared the primary visual cortex. The lesions of the remaining 38 patients with scotoma detectable in both methods were accumulated in area V1, the primary visual cortex. The lesions of 6 patients, who had had persistent scotoma perception for more than 2 years, were situated at the occipital pole. The lesions of 8 patients with vanishing scotoma were concentrated in more rostral areas.