Figure 1
Flowchart of the alcohol responsiveness test designed by Knudsen et al. A) First, the Archimedes Spiral Ratings (ASR) are determined. Per participant, 6 spirals are scored independently by two raters, using the Bain-Findley spirography scale. Per spiral, the ASR is determined by calculating the mean of these Bain-Findley scores of both raters. B) Secondly, the objective alcohol responsiveness is determined for each participant. After determining the most affected hand at T0, an ASR of 3 or higher allows for calculation of the dASR and classification as either a responder (dASR ≥ 2) or non-responder (dASR < 2).
Table 1
Demographic and clinical characteristics.
| PARTICIPANTS WITH CONFIRMED ET DIAGNOSIS (n = 24) | |
|---|---|
| Female gender | 8 (33) |
| Age at registration (years) | 58.2 ± 17.1, 24–91 |
| Age of onset (years) | 18, IQR 27, 0–80a |
| Disease durationb (years) | 21.5, IQR 39, 6–69 |
| Right-handedness | 20 (83) |
| Total tremor scorec,d (FTM-TRS) | 17, IQR 21, 3–46 |
| FTM-TRS part A | 3.5, IQR 6, 0–18 |
| FTM-TRS part Bd | 9, IQR 12, 2–26 |
| FTM-TRS part C | 6.2 ± 4.6, 0–14 |
| Relationship to proband | |
| Self | 8 (33) |
| First degree | 13 (54) |
| Second degree | 3 (13) |
| Currently taking medication for ET | 7 (29) |
| Number of alcoholic drinks per week | 5.5, IQR 7, 0–28 |
| Positive self-reported alcohol responsiveness of their tremor | 12 (50) |
[i] All values are mean ± SD, range; median, IQR, range; or number (%).
NA, not applicable.
a One missing value.
b Calculated as follows: age at registration – age of onset.
c Maximum score total Fahn-Tolosa-Marin Tremor Rating Scale (FTM-TRS) = 92, part A = 24, part B = 36, part C = 32. If (partial) sub-scores were missing, patients were excluded from analysis (N = 17).
d (Part of) FTM-TRS part B is missing in 7 patients, these were excluded from analysis (N = 17).
Figure 2
Distribution of the Archimedes Spiral Ratings (ASRs) of all reconfirmed ET participants for each time point (five-turn spirals, dominant and non-dominant hand). N = 107 spirals. Asterisks (***) indicate significant differences between the two conditions (p < 0.001). Diamonds indicate outliers in the data.
T0: before alcohol intake; T1: one hour after alcohol intake; T2: morning after day of alcohol intake.
Table 2
Tremor severity as indicated by the Archimedes Spiral Rate before and after alcohol intake.
| AVERAGE TWO RATERS | RATER 1 | RATER 2 | |
|---|---|---|---|
| T0 | 5.0 (IQR 3.6, 2.0–9.5) | 5.0 (IQR 2.8, 2.0–9.0) | 5.0 (IQR 3.5, 2.0–10.0) |
| T1 | 3.25 (IQR 1.5, 0.5–9.5)* | 3.0 (IQR 1.0, 0.0–9.0)* | 3.0 (IQR 1.8, 1.0–10.0)* |
| T2 | 4.75 (IQR 3.1, 2.0–9.5) ** | 5.0 (IQR 3.0, 2.0–9.0) ** | 5.0 (IQR 3.3, 2.0–10.0) ** |
[i] All values are displayed as median (interquartile range, range), with a possible range from zero to ten on the Bain Findley Spirography scale. Asterixis indicate statistical differences p < 0.05 between *T1 and T0, ** T2 and T1.
Figure 3
A) Distribution of the Archimedes Spiral Ratings (ASR) of responders versus non-responders for each time point (N = 53 spirals). There is no significant difference between the ASR of responders and non-responders at any time point. Responders’ median ASR at T0 is 5.25 (IQR 2.1; 4–9.5), at T1 3.0 (IQR 1.25; 0.5–7) and at T2 5.25 (IQR 3.13; 2.5–8.5). Non-responders’ median ASR at T0 3.5 (IQR 5.8; 3–9.5), at T1 4.0 (IQR 6.0; 2.5–9.5) and at T2 7.0 (IQR 5.75; 2.5–9.5). For the responders, significant differences were found between all time points. Asterisks (*) indicate significant differences between the two conditions (*p < 0.05, **p < 0.01, ***p < 0.001). T0: before alcohol intake; T1: one hour after alcohol intake; T2: morning after day of alcohol intake. B) Individual courses in time of the ASR split for responders and non-responders. Patient numbers indicate families, letters indicate individuals.
Figure 4
Pedigree of a family with alcohol-responsive essential tremor.