Recording of reversed Uhthoff's phenomenon by visual evoked potentials elicited by pseudorandom binary sequence stimulation

Reversed Uhthoffs phenomenon is a temporal improvement of visual acuity initiated by body cooling in subjects with demyelinating optic neuropathy. Up until the present, it has been difficult to demonstrate Uhthoffs phenomenon by visually evoked potentials (VEPs). We have been able to demonstrate this phenomenon with VEPs elicited by pseudorandom binary sequence stimuli (PRBS-VEP). Case 1 was a 50-year-old woman with right optic neuropathy. Her right visual acuity was 0.02 and improvement of subjective visual acuity, and temporal frequency characteristics of the VEPs were seen after ingestion of cold water. Case 2 was a 29-year-old man with right optic neuropathy and multiple sclerosis. His right visual acuity was 0.4 and the visual acuity improved to 0.8 with ingestion of cold water. The amplitudes and temporal frequency characteristics of the VEPs were also improved. The amplitude of the first order kernel and the temporal frequency characteristics (TFC) of the VEPs were recorded successfully with PRBS-VEP during the short time period the patients exhibited the reversed Uhthoffs phenomenon.