Alcohol challenge and sensitivity to change of the essential tremor rating assessment scale

Abstract

Background The Essential Tremor (ET) Rating Assessment Scale (TETRAS) has shown excellent inter- and intra-rater reliability. To assess the scale’s ability to detect changes in tremor severity, we compared TETRAS performance with standard postural tremor accelerometry during a standardized ethanol challenge. Methods Fifteen adult ET patients received a single oral ethanol dose calculated to reach 0.05 g/dl breath alcohol content (brAC) on two different study days. Two investigators independently assessed the effects with accelerometry on one day and with TETRAS on another day. Measurements were taken at 8 time-points (2 time-points baseline and 6 time-points up to 2 hours post ethanol). Further outcome measures included brAC readings at the same time points. Results Because correlation between TETRAS and accelerometry revealed a logarithmic relation, for all comparisons, accelerometry data were log-transformed and a cumulative score logACC(R+L) was calculated. Correlation between logACC(R+L) and TETRAS was significant (r= 0.57, p<0.01). Repeated measures ANOVA for both TETRAS and accelerometry before and after ethanol showed a significant effect of time-point (F=34.6, p<0.01; F=13.5, p<0.01). Corrected post-hoc tests showed a difference between baseline and each of the following 6 time-points. TETRAS and brAC were significantly correlated (r=−0.29, p<0.01). Intra-rater test-retest analysis between baseline measures showed high correlation (ICC=0.974, p<0.001). The ethanol challenge showed excellent reproducibility. Conclusion We demonstrated sensitivity of the TETRAS performance scale to change after a therapeutic intervention. Our study provides responsiveness validity for TETRAS, further establishing its potential as a valid instrument for ET evaluation in both clinical and research settings.

Early‐ and late‐onset essential tremor patients represent clinically distinct subgroups

“…The strong logarithmic relation between the validated FTM scale and the ASR (Fig. A) suggests that the ASR is indeed a valid measure for tremor severity . Early‐ and late‐onset ET patients differ in important clinical characteristics that might be markers of etiopathological differences as is the case for many other diseases.…”

“…2A) suggests that the ASR is indeed a valid measure for tremor severity. 28,40 Early-and late-onset ET patients differ in important clinical characteristics that might be markers of etiopathological differences as is the case for many other diseases. Prominent examples are Parkinson's disease and Alzheimer's disease.…”

Alternating Thalamic Deep Brain Stimulation for Essential Tremor: A Trial to Reduce Habituation

“…This is not only statistically significant, but arguably also a significant clinical difference. 18 Unfortunately, the tremor control observed in the experimental treatment arm did not translate into patientreported ADL functioning.…”

Dose-escalation study of octanoic acid in patients with essential tremor

“…Baseline tremor severity was measured using accelerometry and a clinical score, TETRAS (12,13). The TETRAS performance score has been shown to be a valid scale with excellent inter-and intrarater reliabilities and sensitivity to change (17,18). Patients then received a single oral serving of ethanol at a total dose of 0.8 g/l of total body water, which was administered together with a sugarless, uncaffeinated drink (19).…”