Early Versus Delayed Treatment of Unilateral Neglect After Stroke

Influence of Prism Adaptation on Spatial Neglect in the Early Versus Delayed Phase After Stroke: a Randomized, Placebo-controlled Trial

'Unilateral neglect' is a disorder that occurs regularly after stroke. It is caused by right- as well as left-sided brain lesions, but more often by right-sided lesions. Patients with this disorder neglect the contralesional side of space and/or their body. Their body axis is often shifted ipsilesionally. A specific disorder that can appear in neglect patients is 'contraversive pushing': a postural deviation to the neglected side because the patient pushes himself away from the ipsi- to the contralesional side. One of the most promising neglect interventions is prism adaptation (PA): inducing an optical shift of the visual field by means of prism glasses. This results in a modulation of brain areas involved in neglect and in an improvement of the neglect symptoms and postural deviation. Research questions: Which period is best suited to maximize therapeutic effects? In this respect the effects of early and delayed PA will be compared, regarding neglect-, postural and cerebral measures. Which factors lead to a less favorable treatment outcome or to therapy resistance for PA? Will the impact of PA be larger if postural factors are taken into account in the prism therapy?

Neglect patients, randomized in the experimental group (Prism adaptation, optical shift of 10 degrees) in the early phase after stroke.

Neglect patients, randomized in the experimental group (Prism adaptation, optical shift of 10 degrees) in the delayed phase after stroke.

Neglect patients, randomized in the placebo group (Prism adaptation, optical shift of 0 degrees) in the early phase after stroke.

Neglect patients, randomized in the placebo group (Prism adaptation, optical shift of 0 degrees) in the delayed phase after stroke.

Neglect patients, randomized in the experimental group (Prism adaptation, optical shift of 10 degrees) in the delayed phase after stroke. In this group, postural aspects are taken into account.

The effect of Prism Adaptation (PA) will be evaluated regarding the degree of neglect, postural control and cerebral functioning, briefly after the therapy cycle and 3 months later. Briefly after the PA sessions and three months later, in patients in the early as well as the delayed phase after stroke: early: PA starting within 4 weeks after stroke; delayed: PA starting 2 months after stroke; OR divided in an early and a delayed group according to the median.

Questionnaires about emotional and functional status. Briefly after the Prism Adaptation (PA) sessions and 3 months later, in patients in the early as well as the delayed phase after stroke: early: PA starting within 4 weeks after stroke; delayed: PA starting 2 months after stroke; OR divided in an early and a delayed group according to the median.

Inclusion Criteria: male or female > 17 years of age stroke patients with clinical neglect, demonstrated by neglect tests Exclusion Criteria: severe ocular abnormalities not being able to perform prism adaptation or neglect tests