Anatomical Study of a Posterior Cerebral Lesion Producing Dyslexia

After an “occipital lobectomy” that resulted in a severe dyslexia and a moderate dysgraphia-dyscalculia, anatomical study showed damage to the posterior extremity of the angular gyrus and degeneration in the posteroinferior pulvinar. This is in contrast to an earlier case that had degeneration in the anterosuperior pulvinar associated with a small anterior temporoparietal infarct and a well-documented receptive-expressive aphasia. However, the role of the pulvinar in speech function remains uncertain. The surgeon should be aware of the short distance between the angular gyrus and both the midline and the occipital pole because a lesion here during an “occipital lobectomy” produces a distressing and durable speech impairment.