Hemispatial neglect, balance and eye-movement control.
Malhotra P., Coulthard E., Husain M.
PURPOSE OF REVIEW: Disorders of spatial awareness and balance following stroke are common but often under-diagnosed. They lead to poor outcome and frequently coexist. Here we focus on recent progress in the understanding of the mechanisms underlying these disorders and potential therapeutic advances. RECENT FINDINGS: Right-hemisphere networks are important for both spatial attention and postural awareness. Neglect patients show multiple oculomotor impairments including reduced saccade amplitude and difficulty retaining spatial locations across saccades. There has been controversy regarding the brain regions associated with neglect, although most studies show the right inferior parietal lobe to be crucial and new imaging modalities have provided insight into neglect caused by subcortical stroke. The 'pusher syndrome' is a poorly understood balance disorder where patients push towards their paretic side, resulting in falls. It may involve impairment of subjective verticality but experimental studies have reported diverse findings. Advances in treatment for neglect include the successful use of prism adaptation and pilot data suggesting noradrenergic stimulation may improve search in selected patients. SUMMARY: New experimental techniques have provided insight into the debilitating disorders of spatial and postural awareness that often follow stroke. There are currently no widely used therapies for neglect but both new behavioural techniques and pharmacological methods are promising.