Visual evoked potentials during XXXX .

@entity1 @entity7995 @entity1781 @entity15 @entity393 @entity221
OBJECTIVES: We sought to evaluate the effect of @entity221 ( @entity221 ) on central conduction pathways by alterations in pattern visual evoked potentials (PVEPs) in normal and demyelinated optic nerves. MATERIALS AND METHODS: We studied PVEP peak latency and amplitudes in 10 normal subjects and six @entity1 with demyelinating @entity1781 before and during @entity221 . RESULTS: In normal subjects, a mean rise in temperature of 2.5 degrees C resulted in a decrease in the second positive peak (P2) latency of 6.1 ms (p < 0.0001) and a slight decline in P2 amplitude of 1.16 muV (p < 0.009). These results were compared to those obtained from six @entity1 with @entity15 . These @entity1 had a history of monocular @entity7995 ; two @entity1 had had bilateral @entity7995 , and one @entity1 had not had involvement of the optic nerve. Average temperature elevations during PVEPs were 1.60 degrees C. PVEPs among these @entity1 showed decrease in mean P2 latencies, except in @entity1 with @entity15 , who showed an increase in latency with 60 min check size in the left eyes. There was a consistent decline in P2 amplitudes. Loss of amplitude was greater among the six optic nerves of those @entity1 having transient, mild losses in visual acuity during @entity221 . Reductions in P2 amplitude were best explained by partial or complete conduction block. CONCLUSIONS: These changes in conduction time and amplitude during @entity221 provide a neurophysiologic correlation to the well-known sensitivity of demyelinated optic nerves to elevated temperatures. They are also relevant to the monitoring of central pathways in the operative or intensive care setting. The demonstrated reversible @entity393 also gives promise to therapeutic manipulation of impaired pathways by impeding the loss of current from denuded nerve fibers.
