Short and long latency cortical potentials evoked by electrical stimulation of the oesophageal mucosa in normal alert humans.
Cerebral responses from the oesophagus were investigated in 16 normal male and female volunteers ranging in age from 20 to 54 years. The stimulus was applied by a naso-oesophageal probe equipped with bipolar ring electrodes. Short and long latency EP (SLEP and LLEP) were observed in all the subjects examined. SLEP consisted in a low threshold potential of 30 to 70 microV amplitude, biphasic or triphasic in shape and of approximately 5 to 10 ms duration; mean latency at the largest peak was 4.5 +/- 1.7 at 25 cm from the nostrils. Early components at about 2.5-3.5 ms and of small amplitude are also present. Recording from the neck at C7 with a common non-cephalic reference, SLEP components occurred from 2 to 6 ms earlier than that from the scalp, suggesting an oligo-synaptic transmission of the excitement via ganglion and lemniscal pathways to the cortex. SLEP was always followed by a complex potential formed of a succession of negative and positive waves with latencies ranging from 20 to 300 ms: the LLEP. This LLEP was usually not very stable and reproducible during the course of successive recordings and in the same subject because it tended to adjust. Preliminary observations concerning the topographical cortical distribution of oesophageal evoked potentials show a circumscribed localization of the SLEP in the parieto-temporal region of the hemisphere whereas LLEP was more widespread. It is the authors' opinion that oesophageal evoked potentials are generated both by the excitation of myelinic fibres with a wide range of conduction speed and of amyelinic fibres from the oesophageal mucosa and the paraoesophageal peripheral nerves of vagal origin.
Caccia
M R
MR
Neurologic Clinic of the University, Ospedale Luigi Sacco, Milano, Italy.
Pace
F
F
Osio
M
M
Bertora
P L
PL
Valla
P L
PL
Sangaletti
O
O
Bianchi Porro
G
G
Mangoni
A
A
D000328:Adult; D000368:Aged; D001364:Awareness; D002540:Cerebral Cortex / Q000502:physiology*; D004558:Electric Stimulation; D004947:Esophagus / Q000294:innervation*; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D005724:Ganglia / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009092:Mucous Membrane / Q000294:innervation; D009412:Nerve Fibers / Q000502:physiology; D009413:Nerve Fibers, Myelinated / Q000502:physiology; D009431:Neural Conduction / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D015203:Reproducibility of Results; D012535:Scalp / Q000294:innervation; D013116:Spinal Cord / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology; D013702:Temporal Lobe / Q000502:physiology; D014630:Vagus Nerve / Q000502:physiology