We studied 8 patients with stroke and hemineglect, who presented with a transient active orientation and explorative behavior, turning head, eyes, and trunk in the opposite direction to any stimuli given in the neglected hemispace, as if repelled. This peculiar active behavior increased on repetitive stimulation, with the patient turning over by more than 180 degrees, with extreme rotation and opisthotonos-like extension of the axial muscles, as if looking for something behind him, his pillow or his bed. This behavior fluctuated during the day and vanished after a few days. We coined the term "hyperneglect" for this behavior, postulating a higher degree in the neglecting behavior or an additional field of hemineglect in the non neglected hemispace, or the release of repellent active behavior from parietal origin by the acute lesion. On CT, five patients showed two sequential uni- or bilateral hemispheric strokes of different ages on CT, while two patients had a large, unilateral infarct associated with hypertensive leukoencephalopathy and contralateral brain edema respectively. This behavioral syndrome seems to be associated with an acute stroke involving the frontal or parietal lobes and a previous lesion in the same or the opposite hemisphere.