Figure 1
PRISMA diagram of study selection.
PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses.
Table 1
Study characteristics and age of ET onset for included samples.
| AUTHOR, YEAR | SAMPLE POPULATION | DESIGN | DIAGNOSTIC CRITERIA | PATIENT CHARACTERISTICS | AGE OF ONSET |
|---|---|---|---|---|---|
| SAMPLES INCLUDING ADULTS | |||||
| Hedera 2013 [22] | Vanderbilt/University of Tennessee (probable clinical); familial ET only; N = 104 | Cross-sectional | ET: presence of bilateral postural and kinetic tremors Familial: ≥2 meioses from a proband | Mean age: 58 ± 7.5 years Mean WHIGET score: 14.8 ± 4.6 Female: 61.5% Familial: 100% | Mean age: 32.1 ± 11.4 years Range: 8–50 |
| Louis 2015a [15]a | CUMC 2000–2009 (clinical); N = 376 | Cross-sectional | ET: WHIGET criteria Familial: self-report (≥1 relatives with ET or tremor) | Mean age: 67.5 ± 15.1 years Mean WHIGET score: 18.8 ± 7.2 Female: 52.1% Familial ET: 62% | Mean age: 44.7 ± 22.5 years |
| Louis 2015b [23]b | ETCBR 2003–2014 (clinical); N = 177 | Prospective cohort | ET: WHIGET criteria Familial: self-report of first- or second-degree relatives | Mean age: 83.7 ± 5.8 years Mean WHIGET score: 24.2 ± 6.7 Female: 61.0% Familial: 27.1% | Mean age: 42.4 ± 22.9 years |
| WHIGET 1995–2000 (community); familial ET only; N = 106 | Prospective cohort | ET: WHIGET criteria Familial: self-report of first- and second-degree relatives | Mean age: 69.8 ± 18.4 years Mean WHIGET score: 16.4 ± 6.7 Female: 59.4% Familial: 100% | Mean age: 56.7 ± 25.6 years | |
| FASET phase 1 2011–2014 (clinical); familial ET only; age of onset ≤50 years; N = 160 | Cross-sectional | ET: physician diagnosis, confirmed by WHIGET criteria Familial: ≥2 living relatives with physician diagnosis of ET | Mean age: 60.0 ± 18.0 years Mean WHIGET score: 20.1 ± 5.2 Female: 51.3% Familial: 100% | Mean age: 27.0 ± 17.8 years | |
| Louis 2018 [25] | FASET phase 2 2015–2018 (clinical); other criteria as in phase 1; N = 203 (98 probands; 105 affected relatives) | Cross-sectional | As in phase 1 | Mean age, years Probands: 68.8 ± 11.2 Affected relatives: 60.9 ± 16.2 Mean WHIGET score Probands: 23.5 ± 6.5 Affected relatives: 17.7 ± 5.9 Female Probands: 59.2% Affected relatives: 60.0% Familial: 100% | Mean age, years Probands: 28.4 ± 19.4 Affected relatives: 33.4 ± 19.9 |
| Louis 2016 [24] | COGNET 2014–2015 (clinical); age ≥55 years; N = 100 | Prospective cohort | ET: physician diagnosis, confirmed by WHIGET criteria Familial: self-report | Mean age: 80.5 ± 8.1 years Mean WHIGET score: 21.5 ± 5.8 Female: 55.0% Familial: 50.0% | Mean age: 39.1 ± 21.2 years Range: 1–83 |
| Ortega-Cubero 2015 [26] | Mayo Clinic (probable clinical); N = 257 cases; 697 controls | Case control | ET: diagnosis by movement disorder specialist Familial: NRc | Mean age: 73.42 ± 11.73 years Mean WHIGET score: NR Female: 53.3% Familial: NR | Mean age: 50.66 ± 19.98 years Range: 5–88 |
| Ross 2011 [27] | Emory University (probable clinical); N = 118 cases; 268 controls | Case control | ET: diagnosis by movement disorder specialist Familial: NR | Mean age: 69.6 ± 12.3 years Mean WHIGET score: NR Female: 57% Familial: NR | Mean age: 46.0 ± 21.7 years Range: 1-83 |
| PEDIATRIC-ONLY SAMPLES | |||||
| Ghosh 2017 [28] | Cleveland Clinic 1984–2011 (clinical); age <21 and ET onset <18 years; N = 211 | Retrospective cohort | ET: bilateral action tremor of the hands and forearms Familial: based on chart review | Mean age: 14.09 ± 5.00 yearsd Mean WHIGET score: NRe Female: 38% Familial: 35% | Mean age: 9.71 ± 5.62 years |
[i] Data are presented as mean ± standard deviation unless otherwise indicated.
a Additional study design data acquired from Louis et al., 2013 [45].
b Additional study design data acquired from Louis et al., 2005 [46] (ETCBR); Louis et al., 1997 [29] (WHIGET); Louis et al., 2013 [47] (FASET).
c Only 1 family member per patient included.
d Mean age at presentation.
e 55% reported functional impairment; 29.4% required medication.
COGNET, Clinical Pathological Study of Cognitive Impairment in Essential Tremor; CUMC, Columbia University Medical Center; ET, essential tremor; ETCBR, Essential Tremor Centralized Brain Repository; FASET, Family Study of Essential Tremor; NR, not reported; WHIGET, Washington Heights-Inwood Genetic Study of Essential Tremor Rating Scale.
Figure 2
Age of onset distribution for patients with ET from the Columbia University Medical Center.
Adapted from Louis et al., 2015 [15].
ET, essential tremor.