ABSTRACT
The differential diagnosis of spells is broad and includes both innocent and life-threatening conditions with a considerable overlap in clinical presentation. Extensive diagnostic testing is often performed, without reaching a final diagnosis, or resulting in false-positives. A thorough medical history, including family history and medication, and physical examination are required to obtain clues about the cause of a spell. An overview of spells with their stereotypic phenotype in general internal medicine practice is presented in this article. Besides, a diagnostic approach is proposed for the clinical evaluation of spells.
Subject(s)
Arrhythmias, Cardiac/etiology , Diagnostic Techniques and Procedures , Flushing/etiology , Adult , Decision Trees , Diagnosis, Differential , Digestive System Neoplasms/diagnosis , Drug-Related Side Effects and Adverse Reactions , Humans , Mastocytosis/diagnosis , Neuroendocrine Tumors/diagnosis , Panic Disorder/diagnosis , Periodicity , Pheochromocytoma/diagnosisABSTRACT
This study aimed at assessing the effects of cognitive activity and mental task load on the correlation dimension of the human electroencephalogram (EEG). Three experimental conditions were created: a baseline condition and two cognitive task conditions, a calculation task and a time estimation task. The calculation task was supposed to induce a higher mental load than the time estimation task, which is regarded as a less complex one. This was verified by a subjective rating scale. All conditions differed significantly in subjective estimated task load. The correlation dimension appeared to be higher in both task conditions compared to the baseline condition. A comparison of the two tasks indicated that the difference in correlation dimension between calculation and time estimation was also significant, with the highest value for calculation. It is concluded that cognitive and mental activity is associated with a higher correlation dimension in the EEG. This implies that the correlation dimension is a sensitive parameter in the analysis of electrical brain activity.
Subject(s)
Cognition/physiology , Electroencephalography , Higher Nervous Activity/physiology , Problem Solving/physiology , Adult , Analysis of Variance , Arousal/physiology , Female , Humans , Reference Values , Task Performance and AnalysisABSTRACT
We describe herein a series of new derivatives of tetrachloro tetraiodo (rose bengal) and report their emission and absorption characteristics. Photochemists and photobiologists may find several of these derivatives useful as alternative sources of singlet oxygen.
