Determinants of cognitive dysfunction in adults with sickle cell related stroke or suspected neurological morbidity.

The prognosis of sickle cell disease (SCD) in adults is determined primarily by damage to targeted organs such as the brain. Cognitive dysfunction in SCD is a common chronic neurological mani-festation but studies remain mostly descriptive in adults. The objective of this study was to better characterize the cognitive profile and the association between cognitive dysfunction and brain lesions. We included adult SCD patients referred for a neurological assessment. An adapted bat-tery of neuropsychological tests was used to assess cognitive deficits. Brain (white matter lesions or infarcts) or arterial (stenosis or occlusion) abnormalities were assessed using brain MRI/MRA and a cervical and transcranial Doppler ultrasound. The battery was completed in 96 patients. The cognitive profile was characterized by deficits in processing speed (58% (95% CI [48-68])), short-term memory (34% (95% CI [24-43])) and working memory (24% (95% CI [15-33])). Brain in-farcts were found in 56% of patients and intracranial vasculopathy in 49%. Twenty percent of pa-tients had no brain abnormalities. Processing speed dysfunction was associated with territorial in-farcts (OR 3.1, p=0.03) and education outside of France (OR 4.7, p=0.02). Short-term memory dysfunction was associated with territorial infarcts (OR 3.4, p=0.01) and a low educational level (OR 8.2, p=0.01). Working memory dysfunction was associated with a low educational level (OR 4.3, p=0.05) and vasculopathy (OR 3.7, p=0.03). Cognitive dysfunction appears to be a hallmark sign of SCD, particularly for adults with sickle cell related stroke or suspected neurological mor-bidity. Assessment of such dysfunction could be used in longitudinal follow up and clinical trials.

Economic and social values in the brain: evidence from lesions to the human ventromedial prefrontal cortex.

Making good economic and social decisions is essential for individual and social welfare. Decades of research have provided compelling evidence that damage to the ventromedial prefrontal cortex (vmPFC) is associated with dramatic personality changes and impairments in economic and social decision-making. However, whether the vmPFC subserves a unified mechanism in the social and non-social domains remains unclear. When choosing between economic options, the vmPFC is thought to guide decision by encoding value signals that reflect the motivational relevance of the options on a common scale. A recent framework, the "extended common neural currency" hypothesis, suggests that the vmPFC may also assign values to social factors and principles, thereby guiding social decision-making. Although neural value signals have been observed in the vmPFC in both social and non-social studies, it is yet to be determined whether they have a causal influence on behavior or merely correlate with decision-making. In this review, we assess whether lesion studies of patients with vmPFC damage offer evidence for such a causal role of the vmPFC in shaping economic and social behavior.