Measurement of Evoked Potentials after Electrical Stimulation of the Human Optic Nerve

2010 ◽  
Vol 51 (10) ◽  
pp. 5351 ◽  
Author(s):  
Marten E. Brelén ◽  
Valerie Vince ◽  
Benoit Gérard ◽  
Claude Veraart ◽  
Jean Delbeke
2020 ◽  
Author(s):  
Reiko Ashida ◽  
Peter Walsh ◽  
Jonathan C.W. Brooks ◽  
Richard J. Edwards ◽  
Nadia L. Cerminara ◽  
...  

AbstractDamage to the cerebellum during posterior fossa surgery can lead to ataxia and in paediatric cases, the risk of cerebellar mutism syndrome. Animal electrophysiological and human imaging studies have shown compartmentalisation of sensorimotor and cognitive functions within the cerebellum. In the present study, electrophysiological monitoring of sensory and motor pathways was carried out to assess the location of limb sensorimotor representation within the human cerebellum, as a potential approach for real time assessment of neurophysiological integrity to reduce the incidence of cerebellar surgical morbidities.Thirteen adult and paediatric patients undergoing posterior fossa surgery were recruited. For sensory mapping (n=8), electrical stimulation was applied to the median nerves, the posterior tibial nerves, or proximal and distal limb muscles and evoked field potential responses were sought on the cerebellar surface. For motor mapping (n=5), electrical stimulation was applied to the surface of the cerebellum and evoked EMG responses were sought in facial and limb muscles.Evoked potentials on the cerebellar surface were found in two patients (25% of cases). In one patient, the evoked response was located on the surface of the right inferior posterior cerebellum in response to stimulation of the right leg. In the second patient, stimulation of the extensor digitorum muscle in the left forearm evoked a response on the surface of the left inferior posterior lobe. In the motor mapping cases no evoked EMG responses could be found.Intraoperative electrophysiological mapping, therefore, indicates it is possible to record evoked potentials on the surface of the human cerebellum in response to peripheral stimulation.


1957 ◽  
Vol 188 (2) ◽  
pp. 238-244 ◽  
Author(s):  
Edward V. Evarts ◽  
John R. Hughes

The lateral geniculate response to electrical stimulation of the optic nerve was recorded in decerebrate cats and in cats anesthetized with Nembutal. Tetanization of the optic nerve at 500/sec. for 20 seconds in nembutalized cats produced a prolonged second subnormality of the geniculate postsynaptic response. Further tetanization during tetanically-induced second subnormality produced posttetanic potentiation (PTP). The degree of PTP (expressed in percentage of the pretetanic level) of the postsynaptic response following a 20-second tetanus was proportional to the degree of second subnormality present at the time the tetanus was applied. PTP was also found to occur during the subnormality which followed a brief train of optic nerve shocks, and during LSD-induced subnormality. PTP of postsynaptic lateral geniculate potentials occurred only rarely in the absence of some form of intentionally induced subnormality.


2009 ◽  
Vol 72 (4) ◽  
pp. 395-400 ◽  
Author(s):  
Hiroyuki Muramatsu ◽  
Kyouichi Suzuki ◽  
Tatsuya Sasaki ◽  
Masato Matsumoto ◽  
Jun Sakuma ◽  
...  

1999 ◽  
Vol 16 (5) ◽  
pp. 889-893 ◽  
Author(s):  
STEPHEN A. GEORGE ◽  
GANG-YI WU ◽  
WEN-CHANG LI ◽  
SHU-RONG WANG

We analyzed postsynaptic potentials and dye-labeled morphology of tectal neurons responding to electrical stimulation of the optic nerve and of the nucleus isthmi in a reptile, Gekko gekko, in order to compare with previously reported interactions between the optic tectum and the nucleus isthmi in amphibians and birds. The results indicate that isthmic stimulation exerts inhibitory and excitatory actions on tectal cells, similar to dual isthmotectal actions in amphibians. It appears that dual actions of the isthmotectal pathway in amphibians and reptiles are shared by two subdivisions of the nucleus isthmi in birds. The morphology of tectal cells responding to isthmic stimulation is generally similar to that of tectoisthmic projecting neurons, but they differ particularly in that some tectoisthmic cells bear numerous varicosities whereas cells receiving isthmic afferents do not. Thus, it is likely that at least some tectoisthmic cells may not be in the population of tectal cells that can be affected by isthmic stimulation. Forty-four percent of injections resulted in dye-coupled labeling, suggesting extensive electrical connections between tectal cells in reptiles.


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