[Preliminary report: use of clinical criteria for the determination of pediatric brain death and confirmation by radionuclide cerebral blood flow].

The medical records of all brain dead patients (n = 228) at the Hospital for Sick Children, Toronto from January 1990 to December 1999 were reviewed. A radionuclide cerebral blood flow study (RCBFS) as a supportive and confirmatory test was performed on 27 patients and the clinical diagnosis of brain death was confirmed on all of them. A RCBFS was performed on 10 out of 27 patients because full clinical evaluation could not be performed due to severe facial injuries or cervical injuries. A RCBFS was performed on 17 patients who underwent a full clinical evaluation, of which 15 cases were due to uncertainty in the clinical etiology of the deep coma and 2 cases were due purely to the need to persuade the family. In recent years, RCBFS was not used as extensively on patients who underwent a full clinical evaluation, reflecting social acceptance and a higher level of clinical certainty in diagnosing brain death in children. This study supports the opinion that brain death can be accurately diagnosed in pediatric patients with clinical criteria alone and confirmatory tests are not necessary in most cases.

Possibly electrotonically-mediated synaptic transmission: time-intensity trades in neurons in the superior olivary complex of cat.

Microelectrode studies were conducted on the probability of firing of neurons in the superior olivary complex of 11 anesthetized cats. Time-intensity trades were established for dichotic clicks. Inhibition was observed for interaural time differences in the region .05--4 msec. The authors point out that these extremely brief times render explanation difficult in terms of chemically-mediate synaptic transmission, and speculate that these results, while of an indirect nature, may be an expression of electrical synaptic transmission.