[Does lateralized hemispheric control of cardiovascular activity exist? A Wada test study]

The question of whether the influence of the cerebral hemispheres on cardiovascular activity exhibits left/right differences is important for the understanding of the psychophysiology of the autonomous nervous system. Experimental results have been contradictory. One experimental procedure used is the intracarotid amobarbital test (Wada test: short anesthesia of one cerebral hemisphere). Even with this test contradictory results have been obtained in various studies, although all involved relatively small of numbers of patients. Some authors have described increases in heart rate following anesthesia of the left hemisphere, while others found little or no effect at all. We therefore searched for evidence of lateralization in a larger number of patients (36) with complex partial seizures. These patients underwent the Wada test as part of the preoperative diagnostic evaluation. In this study, inactivation of the left or right hemisphere did not lead to significantly different effects on heart rate, or on systolic or diastolic blood pressure.