Silas Weir Mitchell's essential tremor.

Silas Weir Mitchell (1829-1914) is recognized as an important American neurologist. Biographers refer in brief to a tremor. The objective of this review was to characterize Mitchell's tremor using handwriting samples, to examine handwriting samples of family members to determine whether this tremor was familial, and study Mitchell's allusions to tremor in personal, scientific, and fictional writings. Primary sources were the Papers of S. Weir Mitchell, College of Physicians of Philadelphia, and Mitchell's scientific and fictional writings. Mitchell's early handwriting was tremor-free yet, by 1873, the writing was tremulous. Handwriting in the 1880s and 1890s shows clear oscillations of moderate-amplitude. By the first decade of the 20th century, his handwriting was virtually illegible. Letters written by two siblings, his mother, and maternal grandfather also reveal tremor. Tremor was not prominent in Mitchell's personal or scientific writings and Mitchell referred to tremor in only 4 of 27 fictional writings. In conclusion, Mitchell had a familial action tremor that began when he was in his early 40's and worsened considerably with age. The likely diagnosis was essential tremor. Curiously, Mitchell rarely alluded to tremor in personal writings and tremor was not prominently featured in his scientific or fictional works.