Interhemispheric disconnection

Interhemispheric disconnection describes lesions of the corpus callosum linking related parts of the two hemispheres.

Presentations:

• left side apraxia - lesion of anterior corpus callosum with interruption of the connections between left and right association motor cortices. Characterised by apraxia of left sided limb movements.
• pure word blindness - lesion of posterior corpus callosum and dominant occipital lobe with interruption of connections between the visual cortex and the angular gyrus - Wernicke's area. Characterised by inability to read, to name colours and to copy writing.
• agenesis of corpus callosum - no connection between the two hemispheres. Characterised by inability to name an object presented visually or by touch to the non-dominant hemisphere.