Emotion recognition in progressive supranuclear palsy.

Progressive supranuclear palsy (PSP) is an atypical parkinsonian syndrome characterised by akinesis, rigidity, falls, supranuclear gaze palsy and cognitive, particularly executive, dysfunction. This study examined the extent to which emotion recognition is affected by PSP. Although deficits in the recognition of emotion have been reported in several diseases which share clinicopathological characteristics with PSP, it has never been studied systematically in PSP. Twenty-four patients with probable or definite PSP and matched healthy controls were studied using tests of facial identity and facial emotion recognition. Patients were not impaired in recognising famous faces, but they showed significant deficits in the recognition of emotions, particularly negative emotions. Moreover, emotion recognition was strongly correlated with the severity of other cognitive deficits in PSP, but not disease duration. Deficits in emotion recognition form an integral part of the cognitive spectrum of the disease. The findings point to the pathological involvement of key regions necessary for the processing of emotions and to a subtype of PSP with cognitive and emotion recognition impairments. The acknowledgement of deficits in emotion recognition is important for management of both patients and their carers.

Parkinson's disease and dopaminergic therapy--differential effects on movement, reward and cognition.

Cognitive deficits are very common in Parkinson's disease particularly for 'executive functions' associated with frontal cortico-striatal networks. Previous work has identified deficits in tasks that require attentional control like task-switching, and reward-based tasks like gambling or reversal learning. However, there is a complex relationship between the specific cognitive problems faced by an individual patient, their stage of disease and dopaminergic treatment. We used a bimodality continuous performance task during fMRI to examine how patients with Parkinson's disease represent the prospect of reward and switch between competing task rules accordingly. The task-switch was not separately cued but was based on the implicit reward relevance of spatial and verbal dimensions of successive compound stimuli. Nineteen patients were studied in relative 'on' and 'off' states, induced by dopaminergic medication withdrawal (Hoehn and Yahr stages 1-4). Patients were able to successfully complete the task and establish a bias to one or other dimension in order to gain reward. However the lateral prefrontal cortex and caudate nucleus showed a non-linear U-shape relationship between motor disease severity and regional brain activation. Dopaminergic treatment led to a shift in this U-shape function, supporting the hypothesis of differential neurodegeneration in separate motor and cognitive cortico-striato-thalamo-cortical circuits. In addition, anterior cingulate activation associated with reward expectation declined with more severe disease, whereas activation following actual rewards increased with more severe disease. This may facilitate a change in goal-directed behaviours from deferred predicted rewards to immediate actual rewards, particularly when on dopaminergic treatment. We discuss the implications for investigation and optimal treatment of this common condition at different stages of disease.