Difficulty in Judging Distance following Parieto-occipital Lobe Damage

Abstract

Difficulty in judging distance is a rare manifestation of brain injury. We report two cases with difficulty in judging distance following brain injury : one case with right parieto-occipital hemorrhage, the other with bilateral parieto-occipital infarction. Both patients showed visual disorientation as described by Holmes. Difficulty in judging distance in our patients was one symptom of visual disorientation. While the basis for difficulty in judging distance in the previous reports lay mainly in subjective complaint, to detect impediment to distance judging objectively we studied ability of judging distance of the first case employing an apparatus (Kowa AS-7JS1) used for acquiring or renewing an oversized vehicle driver's license or Category II driver's license. The performance of the patient was significantly worse than both the normal control and the neglect group. Given the overlapping lesions of our two cases and the cases in the previous reports, the neural basis for judging distance is considered to be the posterior part of the parieto-occipital lobe ; the superior parietal lobule, the posterior part of the inferior parietal lobule, and the cuneus, mainly in the right hemisphere.