Upper facial muscle activity and survival after hypoxic insult in rats.
Spontaneous cerebral biopotentials were monitored during and after hypoxic insults in 30 ketamine-anesthetized rats. Upper facial electromyographic (EMG, mean integrated amplitude) and electroencephalographic (mean zero cross frequency (ZXF) and mean integrated amplitude (MIA] data were recorded within 30 min after reoxygenation and cardiopulmonary resuscitation. The animals were separated into 2 groups based on 24 h survival. EMG in Survivors (n = 16) recovered regularly to pre-insult levels by 30 min after resuscitation. At this time, EMG activity was consistently low in Non-survivors. In contrast, ZXF and MIA, albeit sensitive hypoxia detectors, did not totally discriminate between Survivors and Non-survivors. Absent EMG in Non-survivors may have reflected irreversible hypoxic damage at the brainstem level.
Paloheimo
M P
MP
Department of Anesthesiology, School of Medicine, University of Louisville, KY 40292.
D000818:Animals; D001926:Brain Death / Q000503:physiopathology; D001933:Brain Stem / Q000503:physiopathology; D004569:Electroencephalography; D004576:Electromyography; D005071:Evoked Potentials; D005152:Facial Muscles / Q000294:innervation*; D005154:Facial Nerve / Q000503:physiopathology; D002534:Hypoxia, Brain / Q000503:physiopathology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012815:Signal Processing, Computer-Assisted