Tactile agnosia and tactile aphasia: symptomatological and anatomical differences

Cortex. 1992 Sep;28(3):445-69. doi: 10.1016/s0010-9452(13)80154-2.

Abstract

Two patients with tactile naming disorders are reported. Case 1 (right hand tactile agnosia due to bilateral cerebral infarction) differentiated tactile qualities of objects normally, but could neither name nor categorize the objects. Case 2 (bilateral tactile aphasia after operation of an epidural left parietal haematoma) had as severe a tactile naming disturbance as Case 1, but could categorize objects normally, demonstrating that tactile recognition was preserved. Case 1 may be the first case of tactile agnosia clearly differentiated from tactile aphasia. CT scans of Case 1 revealed lesions in the left angular gyrus, and in the right parietal, temporal, and occipital lobes. Case 2 had lesions in the left angular gyrus and of posterior callosal radiations. Our findings suggest that tactile agnosia appears when the somatosensory association cortex is disconnected by a subcortical lesion of the angular gyrus from the semantic memory store located in the inferior temporal lobe, while tactile aphasia represents a tactual-verbal disconnection.

Publication types

  • Case Reports

MeSH terms

  • Aged
  • Agnosia / diagnosis
  • Agnosia / physiopathology*
  • Agnosia / psychology
  • Agraphia / diagnosis
  • Agraphia / physiopathology
  • Agraphia / psychology
  • Anomia / diagnosis
  • Anomia / physiopathology
  • Anomia / psychology
  • Aphasia / diagnosis
  • Aphasia / physiopathology*
  • Aphasia / psychology
  • Attention / physiology*
  • Brain Damage, Chronic / diagnosis
  • Brain Damage, Chronic / physiopathology*
  • Brain Damage, Chronic / psychology
  • Brain Mapping
  • Cerebral Cortex / physiopathology
  • Cerebral Infarction / diagnosis
  • Cerebral Infarction / physiopathology
  • Cerebral Infarction / psychology
  • Dominance, Cerebral / physiology*
  • Dyslexia, Acquired / diagnosis
  • Dyslexia, Acquired / physiopathology
  • Dyslexia, Acquired / psychology
  • Functional Laterality / physiology*
  • Hematoma, Epidural, Cranial / diagnosis
  • Hematoma, Epidural, Cranial / physiopathology
  • Hematoma, Epidural, Cranial / psychology
  • Humans
  • Male
  • Middle Aged
  • Neurologic Examination
  • Neuropsychological Tests
  • Pattern Recognition, Visual / physiology
  • Psychomotor Performance / physiology
  • Stereognosis / physiology
  • Tomography, X-Ray Computed
  • Touch / physiology*