Objective: To prospectively follow-up a sample of Essential Tremor (ET) patients to identify trends in the progression of motor and cognitive symptoms.

Background: ET is a slowly progressive condition, as observed in limited longitudinal studies.

Method: We assessed 21 ET patients (11 males, disease duration 16.7 ± 11.8) diagnosed with ET or ET-plus at three follow-up points (T0, T1, T2) over 78 months, with an average of 36.5 months between T0 and T1, and 41.3 months between T1 and T2. Evaluations included clinical scales (Fahn-Tolosa-Marin Tremor Rating Scale – FTM, MMSE) and kinematic movement analysis of postural and resting tremor amplitude, and finger-tapping velocity. Statistics included repeated-measures ANOVA, correlation, and regression analyses. Progression was considered both as delta per month and regression slopes.

Results: Overall, 80.95% showed an increase in tremor scores from T0 to T2. FTM score increased from T0 (21.4 ± 12.1) to T1 (28.9 ± 13.4) (p<0.001) and remained stable at T2 (31.95 ± 17.2) (p>0.05). Similarly, the number of body parts involved increased from T0 (1.71 ± 0.8) to T1 (2.9 ± 1.4) (p<0.001), and remained stable at T2 (2.8 ± 1.2) (p>0.05). Fifteen of 21 patients (71.4%) showed greater tremor worsening in the first period than the second. The number of patients with MMSE scores of 25 or lower increased from one (4.76%) to four (19.05%). Subjects with higher FTM scores at baseline exhibited worse MMSE scores (rho=-0.69, p<0.001). The progression of different kinematic parameters was heterogeneous across the group. The increase in resting tremor correlated positively with the increase in postural tremor amplitude (rho: 0.63, p=0.02), and the decrease in MMSE scores (rho: 0.68, p=0.01). In 10 patients (47.6%) movement velocity decreased over time, and greater decrease was associated with shorter disease duration at baseline (rho:0.47, p=0.03). No other clinical-demographic baseline variables predicted greater worsening of motor or cognitive symptoms (all p>0.05).

Conclusion: This study confirms that both motor and cognitive symptoms in ET progress over time. The progression is highly heterogeneous across the sample, and more pronounced in the earlier stages of the disease. A close relationship emerged between resting tremor, postural tremor, and cognition, all showing similar evolutionary trends. Further investigation is needed to identify predictors of ET progression and the role of aging in ET.

References: – Angelini, L., Paparella, G., De Biase, A., Maraone, A., Panfili, M., Berardelli, I., Cannavacciuolo, A., Di Vita, A., Margiotta, R., Fabbrini, G., Berardelli, A., & Bologna, M. (2023). Longitudinal study of clinical and neurophysiological features in essential tremor. European journal of neurology, 30(3), 631–640. https://doi.org/10.1111/ene.15650
– Iglesias-Hernandez, D., Delgado, N., McGurn, M., Huey, E. D., Cosentino, S., & Louis, E. D. (2021). “ET Plus”: Instability of the Diagnosis During Prospective Longitudinal Follow-up of Essential Tremor Cases. Frontiers in neurology, 12, 782694. https://doi.org/10.3389/fneur.2021.782694
– McGurn, M. M., Berry, D. S., Dworkin, J. D., & Louis, E. D. (2022). Longitudinal Progression of Essential Tremor: Do Tremor Severity Scores Increase at a Uniform Rate?. Frontiers in neurology, 13, 871905. https://doi.org/10.3389/fneur.2022.871905

« Back to 2025 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/seven-year-follow-up-of-clinical-and-neurophysiological-features-in-essential-tremor/