Hemispatial neglect in cerebellar stroke.

Cognitive deficits can be associated with cerebellar injury. The purpose of this study is to learn 1) if unilateral cerebellar injury might also cause hemispatial neglect, and if so, 2) if there is a left versus right asymmetry, 3) if the neglect is contralesional (CN) or ipsilesional (IN), and 4) if cerebellar injury might induce neglect by disruption of cerebellar-cortical networks. Participants were 28 patients with unilateral cerebellar stroke who were assessed for neglect within 2 months after the onset of stroke. To investigate if the cerebellar-cerebral network dysfunction induced neglect, 12 patients received perfusion single photon emission computed tomography (SPECT). Eight of the participants demonstrated neglect (28.6%), four with left cerebellar strokes (three with CN and one with IN) and four with right cerebellar strokes (three with IN and one with CN). Among five patients with neglect who had undergone SPECT, only one with ipsilesional neglect showed crossed cerebello-cerebral diaschisis. Neglect induced by cerebellar stroke might be more common than previously reported. Based on the cerebellar-cerebral network hypothesis we expected neglect to be more common with left than right cerebellar injury, but there was an equal number of patients with neglect from right and left sided strokes and the SPECT scan did not provide support of this hypothesis. Thus, this hypothesis cannot also explain the equal number of subject with ipsi- and contralesional neglect and in future studies alternative hypotheses such as vestibular hypothesis will have to be explored.