Polygraphic sleep study in craniopagus twins: (Where is the sleep transmitter?)

Abstract

SU MM AR Y By means of polygraphic recordings complete independence of the sequence of sleeping and waking and of the two sleep states (REM and NREM) could be demonstrated in twins extensively conjoined at the skulls. Functionally important connections in the circulation of the two babies were found during subsequent preoperative investigations. These observations are at variance with the hypothesis of an extraneuronal humoral sleep-inducing factor based on crossed-circulation experiments in animals; moreover they raise a new question about the transportation of the sleepregulating biogenic amines.The union in craniopagus twins may be of any extent from a small superficial connection of two apparently complete individuals to a malformation resulting in the impression of a single head with two faces. Whether surgical separation is a possibility or not depends primarily on the extent and intimacy of the union. Before the necessary meticulous information on anatomical details is obtained in preoperative diagnosis, the crucial question has to be answered whether the twins are two complete individuals with two separate brains or not.We could quickly demonstrate two independently functioning brains in twins extensively conjoined at the skull by polygraphic registration of their behaviour, especially of their sleep states and stages.Crossed circulation experiments in animals have led to the postulation of an extraneuronal humoral sleep-inducing factor. Our results with polygraphic and further diagnostic procedures do not appear to be consistent with such a hypothesis.CASE HISTORY

“Pain monitoring in anesthetized children: first assessment of skin conductance and analgesia‐nociception index at different infusion rates of remifentanil”, recommended preset values for the skin conductance equipment was not used

“…When using the SCR per second in adults, during tetanic stimuli with propofol and without analgesia, 67% of the patients increased their SCR per second (4). This is not in accordance with previous findings (2,4). In the study by Sarbourdin et al (1), the patients who reacted according the skin conductance level, microsiemens, were treated with analgesia.…”

“…It is difficult to understand why they increased the threshold 10 times. The SCR per second does not differ between enough or too much analgesia, then the index is 0.00 SCRÁs À1 (2). The SCR per second to nociceptive stimuli in these patients was associated with the genetic variability in genes believed to influence pain sensitivity (4).…”

“…When 15 sleeping infants were studied six times during 48 h, the variation of the HR was between 110 and 165 with a mean of 141 (2). The HRV used by Sarbourdin et al (1) monitors directly parasympathetic nerve activity.…”

“…The HRV used by Sarbourdin et al (1) monitors directly parasympathetic nerve activity. The SCR per second is not influenced by age (2). The sympathetic nerve activity in preterm infants appears to be developed to a final stage at about 25 weeks of gestational age (5).…”

“…The HR is influenced by the respiratory rhythm (including apnea and hypoxia, the use of mechanical ventilation, and the respiratory distress syndrome) (2), as well as changes in the blood volume status (2). The HR is influenced by the respiratory rhythm (including apnea and hypoxia, the use of mechanical ventilation, and the respiratory distress syndrome) (2), as well as changes in the blood volume status (2).…”