Angular gyrus syndrome revisited: Acalculia, finger agnosia, right-left disorientation and semantic aphasia

Angular gyrus (Gerstmann) syndrome is classically described as linger agnosia, right-left disorientation, agraphia and acalculia in association to lesions in the left angular gyrus. Aphasia is not typically described as part of this syndrome. Here we report a 58 year old right-handed male, with an ischemic lesion to the left angular gyrus, who developed sudden loss of speech expression and comprehension, and slowly recovered over the following few weeks. After several months he showed significant improvement on his language skills with only mild word-finding difficulties, but with substantial difficulties in understanding logic-grammatical relationships, comparison adverbs (e.g. bigger-smaller, younger-older etc., place adverbs (e.g. over-below, on-beneath etc, and time adverbs (e.g. before-after). These language deficits are compatible with a semantic aphasia. Writing difficulties are minimal. In addition, he has important impairments in finger agnosia, right-left discrimination, and in understanding numbers, using numerical concepts, and performing arithmetical operations. We propose that left angular gyrus syndrome should be restated to include acalculia, finger agnosia, right left disorientation and semantic aphasia. A single underlying deficit can account for the simultaneous presentation of these lour clinical signs.