Interhemispheric transfer of language in patients with left frontal cerebral arteriovenous malformation.

Cerebral arteriovenous malformations (AVMs) are frequently evaluated before therapeutic embolization by superselective injection of anesthetics into individual arterial branches so as to determine whether permanent occlusion would affect eloquent function. In Experiment 1, we used this adaptation of the Wada procedure to study three right-handed adult patients with left frontal cerebral AVMs by injecting vessels in Wernicke's and Broca's areas, respectively, and assessing language functions. The results showed that superselective testing in the inferior division of the left MCA in all three patients produced a dense Wernicke's aphasia. Injections into the left frontal regions, however, resulted in right paresis in all patients, but no language deficits including no loss of fluency. In Experiment 2, Patient 2 underwent fMRI activation for spontaneous word-list generation using multi-slice echo planar BOLD techniques at 1.5 Tesla. A voxel-by-voxel comparison of rest vs activation for each task was performed with a Z-score threshold of 2.5 SD for activated voxels. There was activation in the right hemisphere in the insula, frontal operculum pars opercularis, and inferior frontal gyrus, an area homologous to Broca's area in the left hemisphere. There was also activation in the left hemisphere in the Rolandic region, but language function was unaffected during Wada testing in this area. These data suggested that features of expressive language were no longer controlled by the left frontal lobe where the AVM was located, and provided new evidence for interhemispheric re-organization under conditions of chronic neurovascular disease.

Antidepressant treatment and the occurrence of mania in bipolar patients admitted for depression.

We examined the records of 33 patients who had 70 inpatient admissions with a diagnosis of bipolar affective disorder, depressed. During 14 of these admissions, a switch occurred from depression into mania. We compared the treatment patients were on at the time of their switch to treatment during the 56 admissions where there was no switch. We conclude that clinicians must be prepared for depressed bipolar patients to switch to mania regardless of treatment status.

Technique as a Consideration in Modern Dance Injuries.

In brief: Modern dance encompasses many different techniques, each of which makes unique demands on the dancer's body. When these demands are amplified by the repetition required to learn and use any technique, overuse injuries sometimes result. To provide a data base for studying injuries in a significant sample of the modern dance community, we surveyed 164 modern dancers, who reported a total of 229 injuries over the past five years. Injury sites and frequency varied with the dance technique. For example, the rate of knee injuries was higher among dancers using the Graham technique than among those using the Horton technique (25% and 10.8%, respectively), whereas lower back injuries occurred more frequently in Horton than in Graham dancers (21.6% and 16.7%, respectively). Hence, technique is a factor to consider when studying modern dance injuries.

Recent experiments testing an opponent-process theory of acquired motivation.

There are acquired motives of the addiction type which seem to be non-associative in nature. They all seem to involve affective phenomena caused by reinforcers, unconditioned stimuli or innate releasers. When such stimuli are repeatedly presented, at least three affective phenomena occur: (1) affective contrast effects, (2) affective habituation (tolerance), and (3) affective withdrawal syndromes. These phenomena can be precipitated either by pleasant or unpleasant events (positive or negative reinforcers). Whenever we see these three phenomena, we also see the development of an addictive cycle, a new motivational system. These phenomena are explained by an opponent-process theory of motivation which holds that there are affect control systems which oppose large departures from affective equilibrium. The control systems are strengthened by use and weakened by disuse. Current observations and experiments testing the theory are described for: (1) the growth of social attachment (imprinting) in ducklings; and (2) the growth of adjunctive behaviors. The findings so far support the theory.