intrahemispheric disconnection

Last reviewed 01/2018

Intrahemispheric disconnection arises from lesions in the subcortical white matter linking parts of the same hemisphere.

Presentations:

  • conduction aphasia - due to lesion of the arcuate fasciculus linking Wernicke's and Broca's speech areas. Characterised by fluent dysphagic speech, good comprehension of written and spoken material, poor repetition.
  • pure word deafness - due to disconnection between the primary auditory cortex and auditory association areas. Characterised by impaired comprehension of speech. Self-initiated language is normal. Audiometry is normal despite the patient feeling deaf.
  • buccal, lingual and 'sympathetic' apraxia - due to disconnection between association motor cortices in the subcortical region. Characterised by right brachiofacial weakness, apraxia of tongue, lip and left limb movements.