Objective
Unilateral neglect is a post-stroke disorder that impacts negatively on functional outcome and lacks
established, effective treatment. This multi-component syndrome is characterised by a directional bias
of attention away from contralesional space, together with impairments in several cognitive domains,
including sustained attention and spatial working memory. This study aims to test the effects of
guanfacine, a noradrenergic alpha-2A agonist, on ameliorating aspects of neglect.
Methods
Thirteen right hemisphere stroke patients with leftward neglect were included in a randomised double-
blind, placebo-controlled proof-of-concept crossover study that examined the effects of a single dose of
guanfacine. Patients were tested on a computerised, time-limited cancellation paradigm, as well as
tasks that independently assessed sustained attention and spatial working memory.
Results
On guanfacine, there was a statistically significant improvement in the total number of targets found on
the cancellation task when compared to placebo (mean improvement of 5, out of a possible 64).
However, there was no evidence of a change in neglect patients' directional attention bias. Furthermore,
Bayesian statistical analysis revealed reliable evidence against any effects of guanfacine on search
organisation and performance on our sustained attention and spatial working memory tasks.
Conclusions
Guanfacine improves search in neglect by boosting the number of targets found, but had no effects on
directional bias, or search organisation; nor did it improve sustained attention or working memory on
independent tasks. Further work is necessary to determine whether longer-term treatment with
guanfacine may be effective for some neglect patients, and whether it affects functional outcome
measures.