Crossed right hemisphere syndrome following left thalamic stroke

In most right–handed people, language and motor functions are more reliant on systems of the left hemisphere while several non–linguistic visuo–spatial and attentional processes depend more on the right hemisphere. The rare exceptions to these rules provide important clues as to what functions co–lateralise, and are thus crucial for models of cerebral specialization. Here we report on the case of a patient, who, after a lesion restricted to the left thalamic region, showed signs normally associated with right hemispheric injury including motor impersistence, visuo–spatial dysfunction and poor comprehension of facial expression. Language abilities were spared and no signs of apraxia were present, in spite of his right hand, foot and eye preference, a pattern normally associated with conventional cerebral dominance. In spite of his other right hemispheric signs, the patient showed no signs of hemispatial neglect. The patient’s pattern of spared and impaired abilities is compared and contrasted with other rare cases of crossed right hemisphere syndrome.