Affiliations: Institute of Biophysics and Radiation Biology, Brain
Research Unit, University of Freiburg, Hansastrasse 9, 79104 Freiburg,
Germany | Atrium 7, 63589 Linsengericht, Germany | Department of Neuropsychology and Rehabilitation
Science, Universität Regensburg, Universitätsstrasse 31, 93040
Regensburg, Germany | Section for Stereotactic Neurosurgery, University of
Freiburg, Germany | Dept. of Ophthalmology, University of Freiburg,
Killianstrasse 5, 79106 Freiburg, Germany
Note: [] Now at Massachusetts General Hospital, Boston, MA 02114
(USA)
Abstract: Purpose. To study and follow-up achromatopsia, prosopagnosia, and
topographagnosia in a patient who suffered a bilateral stroke of the posterior
cerebral arteries. Methods. Ophthalmological, neuropsychological and
neuroradiological examinations were conducted over a span of 3 years to assess
the amount of brain damage and look for signs of functional recovery. Results.
After the onset of achromatopsia, perception of the color green re-appeared
first, followed by red, yellow, and brown. Blue which had appeared entirely
black was last to return. While reading and color naming have largely
recovered, color discrimination after three years remains poor especially in
dim lighting. Similarly, with prosopagnosia, while the patient has learn to
identify people (including photographs) by individual features, his ability to
perceive and recognize faces and facial expressions holistically remains
severely impaired. Recognition of streets, houses, and topographical layouts
also continues to be affected, while the perception of speed and distance has
somewhat improved. Perimetry further suggests a mild improvement of the
superior hemianopia in his visual fields. Conclusions. Although major deficits
in color, face and place perception remain, some functions impaired by the
stroke have returned par-alleling a partial recovery from the brain lesion as
demonstrated by NMR.
