Objective: To find neuroimaging biomarkers of neurodegeration in patients with essential tremor (ET).

Background: ET is one of the most common movement disorder. The disease progression over time, the increased prevalence with age and the increased risk of degenerative disorders associated with ET, such as Parkinson’s and Alzheimer’s diseases, support the neurodegenerative hypotesis. Furthermore, previous imaging and pathological studies demonstrate brain structural changes in patients with ET.

Methods: We studied 19 ET patients and 15 healthy subjects (HS). Tremor was assessed by means of Fahn-Tolosa-Marin Tremor Rating Scale (FTM-TRS) and accelerometric measures. We ruled out cognitive impairment using by Montreal Cognitive Assessemnt (MoCA). Patients were also assessed using the Frontal Assessment Battery (FAB) and Beck Depression and Anxiety Inventories (BDI–BAI). Participants underwent a standardized 3T-MRI protocol. Total grey matter (GM) and white matter (WM) volume were assessed by means of SIENAX (FSL toolbox), cortical thickness (Cth) using by CAT 12 (SPM 12 toolbox) and subcortical volumes using by FIRST-FSL. Finally, we assessed iron deposition obtained from SWAN images in seven specific Regions of Interest (ROIs): thalamus, putamen, globus pallidus, caudate, substantia nigra, red nucleus and dentate nucleus. We then investigated possible correlations between clinical scores and accelerometric measures of tremor and neuroimaging data.

Results: No differences in total GM, WM and Cth were found between the two groups. Moreover, no differences in terms of iron accumulation were observed between ET patients and HS. Subcortical volumes analysis demonstrated significant differences in thalamus volume bilaterally (p<0.015) in the comparison CS>ET, positively correlating with MoCA. By contrast, thalamus volumes did not correlate with tremor severity, as assessed by clinical scores and accelerometric measures.

Conclusions: Apart for the observation of thalamic atrophy, our study indicates no structural brain abnormalities supporting neurodegenerative hypothesis in ET. Thalamic atrophy positively correlated with cognitive measures in patients, providing further insight into the pathophysiological mechanisms of the disease. However, the lack of correlation between tremor severity and thalamic volume indicates that structural abnormalities does not necessarily play a key role in generating tremor in this condition.

« Back to 2018 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/imaging-neurodegeneration-biomarkers-in-essential-tremor/