- Uhthoff's phenomenon
Uhthoff's phenomenon is the worsening of neurologic
symptom s inmultiple sclerosis after periods ofexercise and increased bodyheat .History
First described by
Wilhelm Uhthoff in1890 as a temporary worsening of vision with exercise in patients withoptic neuritis , later work revealed the link between exercise and increased heat production. The phenomenon can occur with any neurologic deficit caused by demyelination and is possibly due to the effect of increasedtemperature on nerve conduction.Clinical significance
Many patients with MS experience increased fatigue and other symptoms related to MS when exposed to heat. As a result, many patients with MS avoid
sauna s, warm baths, and other sources of heat.References
* W. Uhthoff: "Untersuchungen über die bei der multiplen Herdsklerose vorkommenden Augenstörungen." Archiv für Psychiatrie und Nervenkrankheiten, Berlin, 1890, 21: 55-116 and 303-410.
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