The presence of Uhthoff’s phenomenon and fatigue in the spinal optical form of multiple sclerosis / A presença do fenómeno de Uhthoff e a fadiga na forma óptica espinhal da esclerose múltipla

Abstract

Objective: To describe the frequency and characteristics of Uhthoff's phenomenon and its association to fatigue in spinal optical MS patients, and to evaluate quality of life and depression. Methods: MFIS-BR scale, Beck's depression inventory, quality of life SF-36 scale and a questionnaire based of FDS elaborated by the authors on the influence of heat on fatigue, visual dysfunction and other neurological manifestations were applied. Results: The final sample consisted of 32 patients and 29 healthy individuals. Uhthoff's phenomenon was found in 31.25% and fatigue on 30% of patients, with significant difference between the groups (6.9%; p=0.018). Strong positive correlation was found between fatigue and depression, and vitality of quality of life domain obtained a higher negative correlation to fatigue. There was no association between fatigue and Uhthoff's phenomenon. Conclusion: Uhthoff's phenomenon is present in 1/3 of spinal optical MS patients and is associated to the number of visual events (optical neuritis). Heat mainly worsens fatigue and induces temporary visual dysfunctions in MS. Fatigue is associated to depression and negative impact in quality of life.