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Updated: Jun 26, 2026

Behavioral Assessment of Manual Dexterity in Non-Human Primates
Published on: November 11, 2011
A case of tactile agnosia with a lesion restricted to the post-central gyrus
Bruno Estañol1, José Fidel Baizabal-Carvallo, Horacio Sentíes-Madrid
1Department of Neurology and Psychiatry, The National Institute of Medical Sciences and Nutrition, Salvador Zubiran, Mexico City, Mexico. bestanol@hotmail.com
Abstract:
Tactile agnosia has been described after lesions of the primary sensory cortex but the exact location and extension of those lesions is not clear. We report the clinical features and imaging findings in a patient with an acute ischemic stroke restricted to the primary sensory area (S1). A 73-year-old man had a sudden onset of a left alien hand, without left hemiparesis. Neurological examination showed intact primary sensory functions, but impaired recognition of shape, size (macrogeometrical) and texture (microgeometrical) of objects; damage confined to the post-central gyrus, sparing the posterior parietal cortex was demonstrated on MRI. An embolic occlusion of the anterior parietal artery was suspected as mechanism of stroke. Tactile agnosia with impaired microgeometrical and macrogeometrical features' recognition can result from a single lesion in the primary sensory cortex (S1) in the right parietal hemisphere, sparing other regions of the cerebral cortex which presumably participate in tactile object recognition.
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