Epub ahead of print: Fraser, et al. The time course and phenotype of Uhthoff phenomenon following optic neuritis. Mult Scler. 2011 Dec 6.
"Have you had optic neuritis? If yes you may find this survey on Uhthoff's phenomenon relevant. Uhthoff's phenomenon is blurring of vision in the previously affected eye that occurs with exercise of raised body temperature. It occurs because of failure conduction in demyelinated or thinly remyelinated nerve fibres."
Objective: As there is little information regarding the recovery from Uhthoff's phenomenon (UP), the objective of this study was to assess the spectrum of UP.
Methods: A one-page questionnaire was sent to 80 consecutive optic neuritis (ON) patients seen in a neuro-ophthalmology clinic.
Results: Of the 48 responders to the questionnaire, 52% reported experiencing UP, with a range of follow-up from 1 to 20 years. Only 16% had resolution of UP, all this occurred within 8 weeks of the onset of ON. Of the MS patients with UP, 88% experienced non-visual heat-related phenomenon compared with 30% without UP.
Conclusion: The presence of UP may have a more general significance. If full recovery from UP has not occurred within the first 2 months from the onset of ON, then recovery appears to be uncommon and may therefore be a marker of remyelination in future drug trials.
"I am not sure if the conclusions of this study are correct. I was always taught that the safety factor for conduction of remyelinated pathways was also reduced and that could block and cause UP."