Figure 1.
Written sentence from one of our essential tremor cases, an 89-year-old male who was taking no medications and had neither thyroid disease nor Parkinson's disease.
Table 1.
Demographic and clinical characteristics of essential tremor cases vs. controls
| n = 33 | n = 507 | ||||
| Age — years | 0.801 | ||||
| Median | 79 | 78 | |||
| Interquartile range | (74–84) | (75–82) | |||
| Education — years | 0.0371 | ||||
| Median | 8 | 12 | |||
| Interquartile range | (4–14) | (8–15) | |||
| Sex — no. (%) | 0.002 | ||||
| Male | 19 | (57.6) | 161 | (31.8) | |
| Female | 14 | (42.4) | 346 | (68.2) | |
| Race/ethnicity — no. (%) | 0.552 | ||||
| White | 9 | (27.3) | 150 | (29.6) | |
| Black | 9 | (27.3) | 176 | (34.7) | |
| Hispanic | 15 | (45.5) | 170 | (33.5) | |
| Other | 0 | (0.0) | 11 | (2.2) | |
| Total cranial volume — ml | 0.032 | ||||
| Mean (SD) | 1185.5 | (108.0) | 1137.1 | (124.0) | |
| Range | 1017.3–1442.0 | 819.8–1586.2 | |||
| Comorbidities — no. (%) | |||||
| Diabetes mellitus3 | 7 | (21.2) | 109 | (21.8) | 0.942 |
| Depression3 | 3 | (9.1) | 41 | (8.1) | 0.742 |
| Thyroid disorder3 | 5 | (15.2) | 62 | (12.5) | 0.592 |
| Hypertension3 | 23 | (69.7) | 336 | (67.2) | 0.77 |
| Heart disease3 | 11 | (33.3) | 113 | (22.3) | 0.14 |
| Hyperlipidemia3 | 16 | (48.5) | 236 | (46.5) | 0.83 |
| Peripheral vascular disease3 | 9 | (27.3) | 96 | (19.2) | 0.26 |
| Dementia4 | 2 | (6.1) | 20 | (4.0) | 0.642 |
| Smoking history — no. (%) | 13 | (39.4) | 179 | (35.7) | 0.67 |
Table 2.
Correlates of total white matter hyperintensity (WMH) volume and log total WMH volume
| Characteristic | Total WMH volume | p | Log total WMH volume | p | ||
| Age — year | 0.211 | <0.0001 | 0.211 | <0.0001 | ||
| Education — year | −0.081 | 0.06 | −0.081 | 0.21 | ||
| Sex — mean (SD) | 0.543 | 0.54 | ||||
| Male | 7.09 | (9.03) | 1.28 | (1.26) | ||
| Female | 6.91 | (7.70) | 1.35 | (1.17) | ||
| Race/ethnicity — mean (SD) | 0.0032 | <0.0001 | ||||
| White | 4.98 | (5.28) | 1.04 | (1.17) | ||
| Black | 8.86 | (9.94) | 1.55 | (1.23) | ||
| Hispanic | 6.64 | (7.26) | 1.34 | (1.14) | ||
| Other | 8.99 | (14.95) | 1.30 | (1.37) | ||
| Total cranial volume — ml | 0.101 | 0.027 | 0.11 | 0.016 | ||
| Comorbidities — mean (SD) | ||||||
| Diabetes mellitus4 | 0.0243 | 0.031 | ||||
| Yes | 7.69 | (7.73) | 1.54 | (1.10) | ||
| No | 6.80 | (8.30) | 1.26 | (1.23) | ||
| Depression4 | 0.113 | 0.15 | ||||
| Yes | 8.82 | (9.33) | 1.58 | (1.25) | ||
| No | 6.80 | (8.02) | 1.30 | (1.20) | ||
| Thyroid disorder4 | 0.783 | 0.71 | ||||
| Yes | 6.91 | (8.19) | 1.38 | (1.10) | ||
| No | 7.03 | (8.22) | 1.32 | (1.22) | ||
| Hypertension4 | 0.0323 | 0.028 | ||||
| Yes | 7.45 | (8.38) | 1.41 | (1.19) | ||
| No | 6.10 | (7.72) | 1.16 | (1.23) | ||
| Heart disease4 | 0.123 | 0.043 | ||||
| Yes | 8.59 | (10.61) | 1.52 | (1.17) | ||
| No | 6.46 | (7.14) | 1.26 | (1.21) | ||
| Hyperlipidemia4 | 0.0273 | 0.022 | ||||
| Yes | 6.27 | (7.58) | 1.19 | (1.22) | ||
| No | 7.56 | (8.57) | 1.44 | (1.18) | ||
| Peripheral vascular disease4 | 0.923 | 0.89 | ||||
| Yes | 6.84 | (7.61) | 1.34 | (1.17) | ||
| No | 7.04 | (8.33) | 1.32 | (1.22) | ||
| Smoking history — mean (SD) | 0.863 | 0.93 | ||||
| Yes | 7.30 | (8.84) | 1.33 | (1.25) | ||
| No | 6.82 | (7.79) | 1.32 | (1.18) | ||
| Dementia5 | 0.0103 | 0.019 | ||||
| Yes | 11.69 | (11.00) | 1.93 | (1.27) | ||
| No | 6.78 | (7.97) | 1.30 | (1.20) | ||
Table 3.
Odds of white matter hyperintensity (WMH) and stroke in essential tremor (ET) cases vs. controls
| Model 1 | Model 2 | ||||
| Measure | ETn = 33 | Controln = 507 | OR (95% CI)p | OR (95% CI)p | OR (95% CI)p |
| Log Total WMH volume | 1.75 ± 1.10 | 1.30 ± 1.21 | 1.41 (1.02, 1.94) 0.038 | 1.43 (1.03, 1.99) 0.035 | 1.44 (1.03, 2.01) 0.030 |
| Regional WMH volumes | |||||
| Primary ROI (Cerebellum) | −1.05 ± 0.66 | −1.29 ± 0.81 | 1.52 (0.91, 2.54)0.11 | 1.58 (0.93, 2.67)0.09 | 1.74 (1.01, 3.03)0.049 |
| Secondary ROIs | |||||
| Frontal lobe | 0.31 ± 0.60 | 0.20 ± 0.58 | 1.39 (0.74, 2.63)0.313 | 1.29 (0.68, 2.45)0.433 | 1.38 (0.70, 2.74)0.363 |
| Basal ganglia | −0.59 ± 0.65 | −0.76 ± 0.62 | 1.67 (0.84, 3.31)0.143 | 1.60 (0.82, 3.12)0.173 | 1.82 (0.89, 3.71)0.103 |
| Tertiary ROIs | |||||
| Occipital lobe | −0.75 ± 0.86 | −1.11 ± 1.04 | 1.45 (0.98, 2.15)0.063 | 1.44 (0.98, 2.13)0.073 | 1.56 (1.04, 2.33)0.033 |
| Parietal lobe | 0.16 ± 0.79 | −0.04 ± 0.69 | 1.54 (0.88, 2.69)0.133 | 1.44 (0.83, 2.53)0.193 | 1.48 (0.83, 2.64)0.183 |
| Temporal lobe | −0.54 ± 0.51 | −1.05 ± 0.77 | 3.36 (1.74, 6.52)<0.0013 | 3.38 (1.72, 6.62)<0.0013 | 3.73 (1.87, 7.43)<0.0013 |
| Stroke measures | |||||
| Participant has one or more strokes | 15 (46.9) | 153 (32.3) | 1.85 (0.90, 3.81)0.09 | 1.61 (0.77, 3.36)0.20 | 1.56 (0.73, 3.36)0.25 |
| Number of strokes detected | 0.69 ± 0.93 | 0.55 ±1.15 | 1.09 (0.85, 1.42)0.50 | 1.03 (0.78, 1.35)0.84 | 1.07 (0.80, 1.44)0.65 |
| 1 or more large stroke (≥1 cm) | 7 (21.9) | 40 (8.4) | 3.04 (1.23, 7.46)0.02 | 2.57 (1.02, 6.45)0.045 | 2.56 (0.98, 6.71)0.056 |
| 1 or more small stroke (>3 mm, <1 cm) | 10 (31.3) | 131 (27.6) | 1.19 (0.55, 2.58)0.66 | 1.06 (0.48, 2.33)0.89 | 1.08 (0.47, 2.44)0.86 |
1 For analyses of WMH, Model 1 included all variables that in univariable models were associated with both ET and WMH volume (at an α level of <0.05). Hence, Model 1 included the covariate TCV. Model 2 considered all variables that in univariable models were associated with either ET or WMH volume (at an α level of <0.05), and included the following covariates: age, sex, education, race, diabetes mellitus, hypertension, heart disease, hyperlipidemia, dementia, and TCV.
2 For analyses of stroke, Model 1 included all variables that in univariable models were associated with both ET and stroke presence (at an α level of <0.05). Hence, Model 1 included the covariates sex and TCV. Model 2 considered all variables that in univariable models were associated with either ET or stroke presence (at an α level of <0.05), and included the following covariates: sex, education, hypertension, heart disease, and TCV.
Table 4.
Demographic and clinical characteristics of participants with vs. without one or more stroke on magnetic resonance imaging (MRI)
| n = 168 | n = 3381 | ||||
| Age — year | 0.712 | ||||
| Median | 77 | 78 | |||
| Interquartile range | (74–82) | (75–82) | |||
| Education — year | 0.442 | ||||
| Median | 12 | 12 | |||
| Interquartile range | (8–15) | (8–15) | |||
| Sex — no. (%) | 0.012 | ||||
| Male | 68 | (40.5) | 99 | (29.3) | |
| Female | 100 | (59.5) | 239 | (70.7) | |
| Race/ethnicity — no. (%) | 0.293 | ||||
| White | 51 | (30.4) | 96 | (28.4) | |
| Black | 65 | (38.7) | 113 | (33.4) | |
| Hispanic | 51 | (30.4) | 121 | (35.8) | |
| Other | 1 | (0.6) | 8 | (2.4) | |
| Total cranial volume — ml | 0.034 | ||||
| Mean (±SD) | 1156.7 | (131.5) | 1131.9 | (118.6) | |
| Range | 925.8–1586.2 | 819.8–1565.5 | |||
| Morbidities — no. (%) | |||||
| Diabetes mellitus | 42 | (25.3) | 68 | (20.2) | 0.19 |
| Dementia | 7 | (4.2) | 14 | (4.2) | 0.98 |
| Depression | 16 | (9.5) | 25 | (7.4) | 0.41 |
| Thyroid disorder | 23 | (13.9) | 38 | (11.4) | 0.44 |
| Hypertension | 124 | (75.2) | 213 | (63.2) | 0.007 |
| Heart disease | 53 | (31.5) | 69 | (20.4) | 0.006 |
| Hyperlipidemia | 74 | (44.0) | 159 | (47.0) | 0.53 |
| Peripheral vascular disease | 35 | (21.1) | 64 | (19.0) | 0.59 |
| Smoking history — no. (%) | 59 | (35.5) | 122 | (36.2) | 0.89 |