As there is little information regarding the recovery from Uhthoff phenomenon (UP) in the multiple sclerosis (MS) literature, the objective of this study was to assess the phenotypes of UP. A one-page questionnaire was sent to 80 consecutive optic neuritis (ON) patients seen in a tertiary neuro-ophthalmology clinic. 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. The presence of UP may have a more general phenotypic 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 surrogate marker of remyelination in future drug trials.
- multiple sclerosis
- optic neuritis