Synonyms:
Visual variant of Alzheimer’s disease, Benson’s syndrome
Clinical features:
- Features of Gerstmann’s syndrome (Alexia, Acalculia, Agraphia, Left-right agnosia/disorientation, Finger agnosia)
- Features of Balint’s syndrome (simultanagnosia, oculomotor apraxia, optic ataxia),
- Apperceptive visual agnosia, dressing apraxia, environmental disorientation, hemianopia, transcortical sensory aphasia
- Less commonly: memory or language disturbances
Localises to visual association cortex bilaterally, usually due to Alzheimer’s disease. If visual hallucinations are present, diffuse Lewy body disease is the likely cause (thalamocortical & ascending midbrain pathways).
Pathology:
Usually neurofibrillary tangles and neuritic plaques similar to Alzheimer’s disease but localized to parieto-occipital cortex or temporo-occipital cortex. Rarely features of diffuse Lewy body disease
Findings on Investigations:
CT/MRI: posterior atrophy (parieto-occipital cortex or temporo-occipital cortex)
SPECT/PET: hypometabolism in parieto-occipital cortex or temporo-occipital cortex
References:
- Benson, D.F., R.J. Davis, and B.D. Snyder, Posterior cortical atrophy. Arch Neurol, 1988. 45(7): p. 789-93.