On reversible deafness, generalized anxiety disorder, and the motoric brain: a psychophysiological perspective

Electromyographic (EMG) recording during presentation of loud sounds revealed central motor inhibition in a rare case of conversion disorder with deafness. Two subjects in whom hypnotic deafness was induced resembled the patient. In contrast, patients with generalized anxiety disorder (GAD) showed a significantly delayed return of EMG to baseline, compared with normals and schizophrenics following administration of auditory startle stimuli. Blood pressure (BP) of GAD patients was also slower to return to baseline than that of normals and schizophrenics. BP recorded continuously during seven consecutive tests revealed a striking difference between GAD patients and controls. While the controls' BP generally decreased during the session, pressure of the GAD patients remained at their initial levels. These data are interpreted in relation to allodynamic autonomic regulation as affected by vagal blockade, which appeared to decrease in controls while remaining undiminished in GAD patients. It is suggested that intrusions of uncontrollable worry in GAD patients, and their consequent overuse of certain rostral neural pathways involved in preparation for action prolonged their vagal blockade. A GAD case with typically high frontalis EMG is presented. Frontalis EMGs may provide an exceptionally sensitive indication of neural activity of relevance to GAD. EMG gradients in normal subjects draw attention to Sperry's motoric brain concept, whose influence is strong throughout the paper. Sperry's principle states that the main function of the brain is that of moving the animal in ways that are advantageous for satisfying basic needs and avoiding dangers. Also, with a focus on the motoric brain, some discoveries resulting from brain-recording experiments in freely moving rats are described.