Role of short latency evoked potentials in the diagnosis of brain death.
OBJECTIVE
The aim of this study is to confirm the effectiveness of auditory brain-stem responses (ABRs) and somatosensory evoked potentials (SEPs) in the diagnosis of brain death (BD).


METHODS
ABRs and SEPs were recorded at the same session in 130 BD patients (age range 8-77 years, 81 male and 49 female). Twenty-four cases were submitted to serial recordings from preterminal conditions through BD.


RESULTS
ABRs were absent in 92 cases (70.8%), only waves I or I-II were present in 32 cases (24.6%), while in the remaining 6 patients (4.6%) waves V and/or III were still present, excluding the death of the brain-stem. In 4 cases (3.1%) SEPs showed the absence of all components following the cervical N9, preventing the diagnosis of BD. Among 126 cases (96.9%) with preserved cervical N9-N13 SEPs confirmed the absence of brain-stem activity in 122 cases (93.7%), in whom no waves following P11 or P13 were recordable. SEPs excluded the diagnosis of BD in the remaining 4 cases (3.2%) showing preserved P14 and/or N18. In all pre terminal patients the far-field P14-N18 were present, and their disappearance was closely related to the onset of BD.


CONCLUSIONS
The combined us of ABRs and SEPs was able to confirm BD in almost all patients, providing an objective confirmation of the diagnosis, and to exclude it in 7 cases, thus improving the reliability of diagnosis.
Facco
Enrico
E
Department of Pharmacology and Anesthesiology E. Meneghetti, University of Padua, via C. Battisti 267, 35121 Padua, Italy. enrico.facco@unipd.it
Munari
M
M
Gallo
F
F
Volpin
S M
SM
Behr
A U
AU
Baratto
F
F
Giron
G P
GP
D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000368:Aged; D001926:Brain Death / Q000175:diagnosis*; D002648:Child; D003128:Coma / Q000175:diagnosis / Q000503:physiopathology; D006259:Craniocerebral Trauma / Q000503:physiopathology; D004569:Electroencephalography; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged