[Crossed aphasia: description of a case]

We describe a new case of crossed aphasia in a right-handed patient with a right hemispheric lesion. A right-handed man, 76 year-old, developed a sudden left hemiparesis with sensitive impairment and mutism. He has neither family history of left handeness or ambidexterity or vascular risk factors. CT cerebral scan showed a large infarct of the middle cerebral artery on the right side, with haemorrhagic suffusion. Cerebral MRI and EEG-cartography confirmed the indemnity of the left hemisphere. Aphasia studies confirmed a mutism with spared verbal comprehension, but alexia was present. A year later, left hemiparesis was recovered but aphasia remained. Crossed aphasia is rarely seen. It is caused by a right hemispheric lesion in right-handed subjects. Fluency is most commonly impaired. At onset, mutism is the common symptom, which evolves to expressive aphasia. Several hypothesis have been raised about the possible mechanisms involved. The few number of PET or SPECT studies performed in these patients have disclosed extensive areas of hypometabolism in the right hemisphere, that exceed the size of the image observed with CT scan or MRI.