Table 1
Demographic and Clinical Characteristics of 187 Cases
| Probands (N = 59) | Affected Relatives (N = 128) | p | |
|---|---|---|---|
| Age (years) | 64.1±15.0, 22–91 | 60.5±17.2, 20–93 | 0.181 |
| Female gender | 38 (64.4) | 64 (50.0) | 0.072 |
| White race | 55 (93.2) | 121 (94.5) | 0.743 |
| Right-handed | 57 (96.6) | 117 (91.4) | 0.233 |
| Relationship to proband | NA | ||
| Self | 59 (100) | 0 (0.0) | |
| Child | 0 (0.0) | 33 (25.8) | |
| Sibling | 0 (0.0) | 57 (44.5) | |
| Parent | 0 (0.0) | 15 (11.7) | |
| Grandchild | 0 (0.0) | 3 (2.3) | |
| Aunt/uncle | 0 (0.0) | 4 (3.1) | |
| Nephew/niece | 0 (0.0) | 9 (7.0) | |
| Other (third-degree) | 0 (0.0) | 7 (5.5) | |
| Total tremor score (neurological examination) | 23.5±5.1, 12.5–35.5 | 18.7±5.0, 8.0–32.0 | <0.0011 |
| Intention tremor score4 | 0.85±0.63 (1.0), 0.0–2.0 | 0.59±0.56 (0.5), 0.0–2.0 | 0.0065 |
| Intention tremor6 | 32 (54.2) | 44 (34.4) | 0.012 |
| Tandem gait score | 2.89±3.62 (1.0), 0–10 | 2.40±3.66 (0.0), 0–10 | 0.1025 |
| Greater tandem gait difficulty7 | 13 (28.3) | 32 (29.1) | 0.922 |
| Currently takes daily medication for ET | 38 (64.4) | 33 (25.8) | <0.0012 |
| Age of tremor onset (years) | 22.4±14.8 | 30.9±19.2 | 0.0011 |
| Duration of tremor (years) | 41.7±18.3 | 30.2±17.9 | <0.0011 |
| Diabetes mellitus by history | 6 (10.2) | 17 (13.3) | 0.552 |
| Arthritis by history | 24 (40.7) | 43 (33.6) | 0.352 |
Table 2
Clinical Correlates of IT and Tandem Gait Difficulty in 187 ET cases
| IT1 | Greater Tandem Gait Difficulty2 | |||
|---|---|---|---|---|
| Age (years) | IT− | 58.7±16.9 | TD− | 54.3±15.3 |
| IT+ | 65.9±15.4 | TD+ | 74.9±9.1 | |
| p = 0.0033 | p<0.0013 | |||
| Male gender | IT− | 57 (51.4) | TD− | 52 (46.8) |
| IT+ | 28 (36.8) | TD+ | 18 (40.0) | |
| p = 0.054 | p = 0.444 | |||
| White race | IT− | 107 (96.4) | TD− | 106 (95.5) |
| IT+ | 69 (90.8) | TD+ | 42 (93.3) | |
| p = 0.1255 | p = 0.695 | |||
| Right-handed | IT− | 100 (90.1) | TD− | 102 (91.9) |
| IT+ | 74 (97.4) | TD+ | 43 (95.6) | |
| p = 0.0555 | p = 0.515 | |||
| Total tremor score (neurological examination) | IT− | 18.48±4.58 | TD− | 19.34±5.10 |
| IT+ | 22.63±5.19 | TD+ | 20.89±5.78 | |
| p < 0.0013 | p = 0.103 | |||
| IT1 | IT− | – | TD− | 32 (28.8) |
| IT+ | TD+ | 24 (53.3) | ||
| p = 0.0044 | ||||
| Greater tandem gait difficulty2 | IT− | 21 (21.0) | TD− | – |
| IT+ | 24 (42.9) | TD+ | ||
| p = 0.0044 | ||||
| Currently takes daily medication for ET | IT− | 35 (31.5) | TD− | 33 (29.7) |
| IT+ | 36 (47.4) | TD+ | 23 (51.1) | |
| p = 0.034 | p = 0.014 | |||
| Age of tremor onset (years) | IT− | 28.7±18.3 | TD− | 24.8±15.3 |
| IT+ | 27.3±18.3 | TD+ | 35.0±21.2 | |
| p = 0.613 | p = 0.0063 | |||
| Duration of tremor (years) | IT− | 30.4±17.3 | TD− | 30.0±15.9 |
| IT+ | 39.1±19.6 | TD+ | 40.2±21.5 | |
| p = 0.0023 | p = 0.0073 |
ET, Essential Tremor; IT, Intention Tremor; IT–, Intention Tremor Absent; IT+, Intention Tremor Present; TD–, Tandem Gait Difficulty Absent; TD+, Tandem Gait Difficulty Present.
For IT, the table demonstrates either the mean±standard deviation of a variable (e.g., age) by category of IT (IT– vs. IT+) or it demonstrates the number (%) with IT in each variable category (e.g., males vs. females, whites vs. non-whites). For tandem gait difficulty, the table demonstrates either the mean±standard deviation of a variable (e.g., age) by category of tandem gait difficulty (TD– vs. TD+) or it demonstrates the number (%) with tandem gait difficulty in each variable category (e.g., males vs. females, whites vs. non-whites).
Figure 1
Intention tremor score (both arms) in probands (open red circles) and relatives (closed blue squares). Vertical grid lines run through the data points in each family. Data points were identical for some individuals in the same family and in these instances would appear as a single data point.
