Neural-network-based classification of cognitively normal, demented, Alzheimer disease and vascular dementia from single photon emission with computed tomography image data from brain.

Single photon emission with computed tomography (SPECT) hexamethylphenylethyleneamineoxime technetium-99 images were analyzed by an optimal interpolative neural network (OINN) algorithm to determine whether the network could discriminate among clinically diagnosed groups of elderly normal, Alzheimer disease (AD), and vascular dementia (VD) subjects. After initial image preprocessing and registration, image features were obtained that were representative of the mean regional tissue uptake. These features were extracted from a given image by averaging the intensities over various regions defined by suitable masks. After training, the network classified independent trials of patients whose clinical diagnoses conformed to published criteria for probable AD or probable/possible VD. For the SPECT data used in the current tests, the OINN agreement was 80 and 86% for probable AD and probable/possible VD, respectively. These results suggest that artificial neural network methods offer potential in diagnoses from brain images and possibly in other areas of scientific research where complex patterns of data may have scientifically meaningful groupings that are not easily identifiable by the researcher.

Capgras syndrome: a clinical manifestation of watershed cerebral infarct complicating the use of extracorporeal membrane oxygenation

Ischaemic cerebral accidents are frequent following extracorporeal membrane oxygenation (ECMO), especially after fixing the reinjection cannula in the right primitive carotid artery, which leads to an interruption in downstream flow. We describe a rare and unusual symptom of cerebral ischaemic accident that is known as Capgras syndrome. This feature is interesting because it may be documented by computed tomography (CT) scan and particular electroencephalography signals. It appears that our observation represents the first documented case of Capgras syndrome complicating ECMO. This incident emphasizes the potential hazards associated with right common artery ligature for venoarterial extracorporeal membrane oxygenation (VAECMO). In addition, it shows that this psychiatric symptom (that has been interpreted psychodynamically for many years) can have an organic basis, which should be studied.