Corneal reflex responses to mechanical and electrical stimuli in coma and narcotic analgesia in humans.
The corneal reflex, a bilateral eye-blink, can be elicited in humans either by mechanical or electrical corneal stimulation. Both in comatose patients and in normal subjects injected with the opiate fentanyl, the electrically-evoked corneal reflex was more suppressed than the mechanically-evoked reflex. We propose that the mechanical input yields a reflex more resistant to depression of the corticoreticular drive and to narcotic analgesia, because it exploits temporal summation at central synapses, whereas the electrical input exploits spatial summation.
Cruccu
G
G
Department of Neurological Sciences, University of Rome, La Sapienza, Italy.
Leardi
M G
MG
Ferracuti
S
S
Manfredi
M
M
D000328:Adult; D000698:Analgesia; D001767:Blinking / Q000502:physiology*; D003128:Coma / Q000503:physiopathology*; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D008297:Male; D009294:Narcotics / Q000494:pharmacology; D010812:Physical Stimulation
D009294:Narcotics