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Sleep Disturbances and Their Correlates in Essential Tremor and Essential Tremor Plus: A Questionnaire-Based Case–Control Study Cover

Sleep Disturbances and Their Correlates in Essential Tremor and Essential Tremor Plus: A Questionnaire-Based Case–Control Study

Tremor and Other Hyperkinetic Movements
Volume 16 (2026): Issue 1
By: ,  ,  ,  ,  ,  ,  ,  ,   and    
Open Access
|Sep 2026
Figures & tables

Figures & Tables

Table 1

Demographic and clinical characteristics of study participants.

SOCIO-DEMOGRAPHICS
CHARACTERISTICCONTROL (n = 100)ET (n = 60)ET-PLUS (n = 40)χ² (df = 1); KRUSKAL WALLISp-VALUE
Age (years), mean ± SD (range)44.0 ± 12.6 (24–69)42.3 ± 14.5 (17–66)54.0 ± 13.8 (22–75)H(2) = 7.69, p = 0.021Control vs ET: p = 1.000 (ns)
Control vs ET-plus: p = 0.024 (significant)
ET vs ET-plus: p = 0.058
Sex (M/F)66/3447/1329/11χ² = 2.83p = 0.244
Disease Duration (years)7 (IQR: 5–12)10 (IQR: 6–18)
Hypertension, n(%)11 (11%)14 (23%)15 (38%)1.7018780.192043
Diabetes, n (%)3 (3%)6 (10%)10 (25%)2.9792910.084336
Ischemic Heart Disease, n (%)0 (0%)6 (10%)1 (3%)1.0816690.298324
Hypothyroidism, n(%)4 (4%)2 (3%)1 (3%)––
Tremor Feature
Bilateral upper limb tremors–60 (100%)40 (100%)––
Lower limb tremors–14 (23%)15 (38%)1.70.192
Voice tremors–20 (33%)23 (58%)4.780.029*
Head tremors–8 (13%)13 (33%)4.220.040*
Tongue tremors–13 (22%)16 (40%)3.080.079
Table 2

Tremor rating scale scores in ET vs ET-plus patients.

TREMOR SCALEET (n = 60)ET-PLUS (n = 40)MANN-WHITNEY U p-VALUEɛ²
TETRAS ADL subscale (0–48)16 (11, 20)22 (14, 30)<0.0010.74
TETRAS Performance subscale (0–64)24 (20, 29)34 (23, 41)<0.0010.766
TETRAS Total score (0–112)41 (32, 48)58 (37, 72)<0.0010.78
FTMRS Total score (0–144)30 (25, 37)44 (30, 63)<0.0010.798
FTMTRS Severity%(0–144)21 (17, 26)31 (21, 44)<0.0010.795
FTMRS Disability level1 (1, 2)2 (1, 3)<0.0010.884

[i] *Data are presented as median (IQR) unless otherwise specified.

Figure 1

Tremor rating scales in ET and ET-plus groups.

Table 3

Pittsburgh Sleep Quality Index (PSQI) scores across groups.

PSQI COMPONENTSCONTROL (n = 100)ET (n = 60)ET-PLUS (n = 40)KRUSKAL-WALLIS (df = 2)p-VALUEɛ²ET vs CONTROLET-PLUS vs CONTROLET vs ET-PLUS
Global PSQI score3 (2, 4)4 (3, 7)5 (3, 12)30.1<0.0010.151<0.001*<0.001*0.164
Component 1: Subjective sleep quality1 (0, 1)1 (1, 2)1 (1, 2)48.91<0.0010.246<0.001*<0.001*0.095
Component 2: Sleep latency1 (1, 1)1 (0, 1)1 (0, 1)3.510.1730.0180.1390.9090.561
Component 3: Sleep duration0 (0, 0)0 (0, 1)1 (0, 1)14.82<0.0010.0750.186<0.001*0.128
Component 4: Sleep efficiency0 (0, 1)1 (0, 1)1 (0, 2)11.940.0030.060.018*0.010*0.664
Component 5: Sleep disturbances1 (0, 1)1 (1, 1)1 (1, 2)38.98<0.0010.196<0.001*<0.001*0.333
Component 6: Sleep medication use0 (0, 0)0 (0, 0)0 (0, 0)21.37<0.0010.107<0.001*<0.001*0.577
Component 7: Daytime dysfunction0 (0, 1)1 (0, 1)1 (1, 2)37.91<0.0010.191<0.001*<0.001*0.039*

[i] *Data are presented as median (IQR) unless otherwise specified.

Figure 2

Distribution of Global PSQI scores across Control, ET, and ET-plus groups.

Table 4

Probable RBD, RLS, Somnambulism and Sleep Apnea screening across groups.

VARIABLECONTROL (n = 100)ET (n = 60)ET-PLUS (n = 40)χ² (df = 2)p-VALUEɛ²ET vs CONTROLET-PLUS vs CONTROLET vs ET-PLUS
MSQ I – Probable RBD (yes/no)9%17%30%14.94<0.0010.0750.012*<0.001*0.639
MSQ – RLS (yes/no)0%20%25%37.32<0.0010.188<0.001*<0.001*0.133
MSQ – Somnambulism (yes/no)0%0%3%40.1350.02–0.2540.439
BQ – Sleep Apnea (high risk)7%18%30%12.540.0020.0630.0730.001*0.367
Figure 3

Prevalence of other sleep disorders across ET, ET plus and Controls.

Table 5

Cognitive, sleepiness, and psychiatric measures across groups.

VARIABLECONTROL (n = 100)ET (n = 60)ET-PLUS (n = 40)KRUSKAL WALLIS (df = 2)p-VALUEɛ²ET vs CONTROLET-PLUS vs CONTROLET vs ET-PLUS
MMSE score30 (29, 30)30 (30, 30)29 (23, 30)–––––<0.001*
ESS > 9 (Excessive sleepiness)1 (0, 3)3 (1, 5)4 (3, 7)21.15<0.0010.1060.007*<0.001*0.301
RLS severity (0–40)0 (0, 0)6 (5, 12)5 (3, 9)26.86<0.0010.135<0.001*<0.001*0.795
GAD-7 (Anxiety severity)0 (0, 3)6 (3, 9)5 (4, 7)83.02<0.0010.419<0.001*<0.001*0.974
PHQ-9 (Depression severity)3 (1, 6)5 (3, 9)5 (3, 6)23.48<0.0010.118<0.001*0.006*0.665

[i] *Data are presented as median (IQR) unless otherwise specified.

Figure 4

Correlation matrices of clinical and sleep parameters across ET, ET plus and Controls.

DOI: https://doi.org/10.5334/tohm.1234 | Journal eISSN: 2160-8288
Journal RSS Feed
Language: English
Page range: 50 - 50
Submitted on: May 10, 2026
Accepted on: Aug 25, 2026
Published on: Sep 3, 2026
Published by: Ubiquity Press
In partnership with: Paradigm Publishing Services
Keywords:
Essential tremor,
Essential tremor plus,
Sleep disturbances,
Pittsburgh Sleep Quality Index,
Epworth Sleepiness Scale,
REM sleep behaviour disorder,
Restless leg syndrome,
Non-motor symptoms

© 2026 Ravi Prakash Singh, S. Mythirayee, Doniparthi Venkata Seshagiri, Rohan Mohale, Pramod Kumar Pal, Bindu M. Kutty, Jitender Saini, Nitish L. Kamble, Vikram Holla, Ravi Yadav, published by Ubiquity Press
This work is licensed under the Creative Commons Attribution 4.0 License.

Volume 16 (2026): Issue 1
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