Table 1.
Demographic and clinical features of ET cases in four ET case samples
| Population-Based Study in Northern Manhattan [8,11,12] | Study of the Environmental Epidemiology of ET [9] | Family Study of Essential Tremor [13,14] | Essential Tremor Centralized Brain Repository [5,15] | |
|---|---|---|---|---|
| Sample size | 106 | 388 | 160 | 177 |
| Age in years | 69.8 ± 18.4 | 67.4 ± 15.3 | 60.0 ± 18.0 | 83.7 ± 5.8 |
| Female gender | 63 (59.4) | 201 (51.8) | 82 (51.3) | 108 (61.0) |
| Education in years | Not available | 15.1 ± 3.8 | 16.4 ± 3.5 | 14.9 ± 3.2 |
| Total tremor score | 16.4 ± 6.7 | 18.8 ± 7.2 | 20.1 ± 5.2 | 24.2 ± 6.7 |
| Tremor duration in years | 15.4 ± 18.8 | 22.8 ± 18.7 | 32.8 ± 19.3 | 41.3 ± 22.3 |
| Age of tremor onset in years | 56.7 ± 25.6 | 44.7 ± 22.5 | 27.0 ± 17.8 | 42.4 ± 22.9 |
| Currently taking medication for tremor | 5 (4.7) | 209 (53.9) | 79 (49.4) | 115 (65.0) |
| Family history of ET | 106 (100) | 119 (30.7) | 160 (100) | 48 (27.1) |
| Voice tremor on examination | 16 (15.1) | 118 (30.4) | 26 (16.3) | 71 (40.1) |
| Head tremor on examination | 19 (17.9) | 143 (36.9) | 60 (37.5) | 92 (52.0) |
| Self-reported head tremor | 9 (8.5) | 131 (33.8) | 58 (36.3) | 53 (29.9) |
| Moderate or greater tremor in one or both arms during spiral drawing | 74 (69.8) | 197 (50.8) | 98 (61.3) | 159 (89.8) |
| No tremor or mild tremor in both arms during spiral drawing but screened positive for head tremor and had head tremor on examination | 3 | 40 | 10 | 3 |
All values are means ± standard deviations or numbers (percentages)