Table 2.
Correlation between age at onset and other characteristics of tremor (n = 42 patients)
| AAO ≤ 30 years (early onset ET) | AAO ≥ 55 years (late onset ET) | p | |
|---|---|---|---|
| (n = 14) | (n = 28) | ||
| Family history of essential tremor (n = 42) | 93% (n = 13) | 36% (n = 10) | 0.0007 |
| Benefit of alcohol (n = 33) | 54% (n = 6) | 9% (n = 2) | 0.008 |
| Duration of tremor, years (SD) (n = 42) | 29 (+/−16) | 6.5 (+/−6) | <0.0001 |
| TETRAS score/duration of tremor (SD) (n = 42) | 0.4 (+/−0.2) | 2.3 (+/−2.3) | <0.0001 |
| Head tremor (n = 42) | 21% (n = 3) | 29% (n = 8) | 1.00 |
| Lower limbs tremor (n = 42) | 21% (n = 3) | 0% (n = 0) | 0.03 |
| Rest tremor (n = 42) | 21.4% (n = 3) | 17.8% (n = 5) | 0.85 |
| Mean frequency, Hertz (SD) (n = 42) | 7.0 (+/−2) | 6.2 (+/−1) | 0.23 |
| TETRAS score (SD) (n = 42) | 9.6 (+/−4) | 7.8 (+/−5) | 0.15 |
| Response to beta-blockers (n = 23) | 77% (n = 10) | 70% (n = 7) | 1.00 |
| Response to primidone (n = 10) | 80% (n = 4) | 60% (n = 3) | 1.00 |
AAO age at onset, SD standard deviation, TETRAS The Essential Tremor Rating Assessment Scale