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Balint's syndrome in Alzheimer's disease: visuospatial functions
M F Mendez1, J Turner, G C Gilmore
1Department of Neurology, St. Paul-Ramsey Medical Center/University of Minnesota 55101.
The International Journal of Neuroscience
|October 1, 1990
Summary
Alzheimer's disease patients with Balint's syndrome show impaired visuospatial processing due to decreased sensitivity to low spatial frequencies. This suggests damage to the magnocellular visual system.
Area of Science:
- Neuroscience
- Ophthalmology
- Neurology
Background:
- Alzheimer's disease (AD) can present with visuospatial deficits.
- Balint's syndrome is an uncommon visual processing disorder.
- The underlying mechanisms of Balint's syndrome in AD are not fully understood.
Observation:
- Three AD patients with Balint's syndrome were compared to three AD patients without the syndrome.
- Balint's syndrome patients could not integrate visual stimuli.
- These patients exhibited left visual field attentional deficits.
Findings:
- Balint's syndrome patients had significantly reduced contrast sensitivity for low spatial frequency gratings.
- Visual evoked potentials (P100) were normal, indicating no primary visual pathway damage.
- Impaired global visuospatial analysis was observed.
Implications:
- Balint's syndrome in AD may stem from damage to the magnocellular visual system.
- Occipitoparietal association cortex or optic nerves could be affected.
- Understanding these deficits may aid in diagnosing and managing AD subtypes.