Multiple Sclerosis, December 2001,
vol. 7, no. 6, pp. 389-401(13)
Failures on visuoperceptual neuropsychological
tasks (on neuropsychological tests of visuo-spatial perception or on tests
concerning semantic properties of visual objects), may indicate focal deficits
of visuoperceptual function, or could be the result of (an)other (peripheral)
visual deficit(s), or be the effect of a more general cognitive decline.
In multiple sclerosis (MS) patients
exhibiting sufficient visual acuity and not showing severe cognitive deterioration,
impairment on a comprehensive set of 31 visuoperceptual neuropsychological
tasks was compared with spatial resolution deficits (SRD), temporal resolution
deficits (TRD) for visual stimuli, abnormal pattern shift visual evoked
potential (PSVEP) responses, and failing scores on neuropsychological tasks
other than visuoperceptual tasks.
Impairment on the visuoperceptual
neuropsychological tasks was highly independent from the other abnormal
visual and cognitive neurological impairments examined, suggesting that
it mostly represented focal deficits.
Only TRD in both eyes related to
this impairment and this relationship was rather weak. Thus in some MS
patients a slowed visual information processing may be one of the combined
deficits underlying visuoperceptual neuropsychological task impairment.
Given that SRD and TRD were not related
to another stage of MS and reflect disturbances of a P (parvocellular channel
and ventral stream projections) and M (magnocellular channel and dorsal
stream projections) visual-system function respectively, demyelination
of a certain M pathway may become a co-determinant of visuoperceptual neuropsychological
task impairment more rapidly than damage to a certain P pathway.
© 2002 ingenta
Vleugels L. [2] *; Lafosse C. [2];
van Nunen A. [1]; Charlier M. [1]; Ketelaer P. [1]; Vandenbussche E. [2]
[1] Department of Rehabilitation,
National Multiple Sclerosis Centre, B-1820 Melsbroek, Belgium [2] Laboratory
for Research in Neuropsychology, Department of Neuro- and Psychophysiology,
University Campus Gasthuisberg, University of Leuven, B-3000 Belgium [*]
Correspondence: L Vleugels, Nationaal M.S. Centrum, Vanheylenstraat, 16,
B-1820 Melsbroek, Belgium
Abstract: