Grey matter correlates of dystonic soft signs in essential tremor

• Published in: Parkinsonism & related disorders 2023-07, Vol.112, p.105457-105457, Article 105457
• Main Authors: Brinker, Dana, Granert, Oliver, Gövert, Felix, Tödt, Inken, Baumann, Alexander, Zeuner, Kirsten E., Wolke, Robin, Deuschl, Günther, Becktepe, Jos S.
• Format: Article
• Language: English
• Subjects: Dystonic tremor; Essential tremor; Essential tremor plus; Grey matter alterations; VBM
• ISSN: 1353-8020; 1873-5126
• DOI: 10.1016/j.parkreldis.2023.105457

Questionable signs of dystonia are a common finding in patients with essential tremor (ET). Brain structural alterations in ET patients plus dystonic soft signs (ET + ds) in comparison to ET patients without dystonic soft signs (ET-ds) or patients with tremor associated with manifest dystonia (TAWD) have not been examined yet. Therefore, our study aims to explore alterations of brain grey matter in patients with ET + ds. A total of 68 elderly patients with ET-ds (n = 32), ET + ds (n = 20) or idiopathic cervical dystonia with dystonia associated action tremor of the upper limbs (TAWD, n = 16) and 42 age-matched healthy controls underwent a clinical and electrophysiological assessment and 3T MRI. For grey matter alterations T1 MRI images were analysed by voxel-based morphometry. Additionally, regression analyses with clinical parameters (tremor frequency, severity and disease duration) were performed. VBM showed a significant increase of grey matter in the right lentiform nucleus in ET + ds and TAWD compared to HC and ET-ds. Further, an increase of cortical grey matter in the middle frontal gyrus in ET + ds was shown. The hypertrophy of the lentiform nucleus in ET + ds was correlated with disease severity and duration. Patients with ET + ds showed grey matter brain structural alterations similar to TAWD. Our findings suggest an involvement of the basal ganglia-cortical loop in ET + ds which may indicate a pathophysiological similarity with TAWD rather than ET. •Questionable signs of dystonia are a common finding in patients with ET plus.•VBM shows an increase of grey matter in the right lentiform nucleus in ET plus.•Lentiform nucleus hypertrophy is correlated with disease severity and duration.