Diverse attention deficits in patients with neurologically symptomatic and asymptomatic Wilson's disease

Cognitive deficits in patients with Wilson's disease (WD) have been reported in several studies, but there was no detailed analysis of the various components of attention, one of the most significant factors of the executive system. Our study determined the pattern of deficits in attention subsystems in WD patients, including selective attention, divided attention, attention switching, and sustained attention.

We examined 67 WD patients using the Test of Everyday Attention (TEA)-33 participants with neurological symptoms and 34 who were neurologically asymptomatic, but most with mild hepatic dysfunctions. The results were compared with 43 matched healthy controls.

The group of WD patients with neurological symptoms performed significantly worse (p < .05) in all components of attention: sustained attention, selective attention, divided attention, and attentional switching. WD patients without neurological symptoms exhibited significantly lower results in one component-sustained attention (p < .05). None of the TEA subtests scores were associated significantly with Unified Wilson's Disease Rating Scale scores, which may reflect that the cognitive and neurological consequences of WD are relatively independent.

We found a deficiency in all components of attention in neurological WD patients. The most frequently disturbed function was attention switching. Relatively milder deficits concerned divided, selective, and sustained attention. These are all abilities creating the core of the executive system and are regulated by subcortical prefrontal circuits, which are usually dysfunctional in WD patients. In neurologically asymptomatic patients, an isolated deficit of sustained attention occurs; this may be a sign of mild hepatic encephalopathy.