@article{IsaiasMarzeganPezzolietal.2012,
  author    = {Isaias, Ioannis U. and Marzegan, Alberto and Pezzoli, Gianni and Marotta, Giorgio and Canesi, Margherita and Biella, Gabriele E. M. and Volkmann, Jens and Cavallari, Paolo},
  title     = {A role for locus coeruleus in Parkinson tremor},
  series = {Frontiers in Human Neuroscience},
  volume    = {5},
  journal   = {Frontiers in Human Neuroscience},
  number    = {179},
  doi       = {10.3389/fnhum.2011.00179},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-133955},
  year      = {2012},
  abstract  = {We analyzed rest tremor, one of the etiologically most elusive hallmarks of Parkinson disease(PD), in 12 consecutive PD patients during a specific task activating the locus coeruleus (LC) to investigate a putative role of noradrenaline (NA) in tremor generation and suppression. Clinical diagnosis was confirmed in all subjects by reduced dopamine reuptake transporter (DAT) binding values investigated by single photon computed tomography imaging (SPECT) with [\(^{123}\)I] N-\(\omega\)-fluoropropyl-2 \(\beta\)-carbomethoxy-3 \(\beta\)-(4-iodophenyl) tropane (FP-CIT). The intensity of tremor (i.e., the power of Electromyography [EMG] signals), but not its frequency, significantly increased during the task. In six subjects, tremor appeared selectively during the task. In a second part of the study, we retrospectively reviewed SPECT with FP-CIT data and confirmed the lack of correlation between dopaminergic loss and tremor by comparing DAT binding values of 82 PD subjects with bilateral tremor (n = 27), unilateral tremor (n = 22), and no tremor (n = 33). This study suggests a role of the LC in Parkinson tremor.},
  language  = {en}
}
@article{PozziBolzoniBiellaetal.2023,
  author    = {Pozzi, Nicol{\´o} Gabriele and Bolzoni, Francesco and Biella, Gabriele Eliseo Mario and Pezzoli, Gianni and Ip, Chi Wang and Volkmann, Jens and Cavallari, Paolo and Asan, Esther and Isaias, Ioannis Ugo},
  title     = {Brain noradrenergic innervation supports the development of Parkinson's tremor: a study in a reserpinized rat model},
  series = {Cells},
  volume    = {12},
  journal   = {Cells},
  number    = {21},
  issn      = {2073-4409},
  doi       = {10.3390/cells12212529},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-357721},
  year      = {2023},
  abstract  = {The pathophysiology of tremor in Parkinson's disease (PD) is evolving towards a complex alteration to monoaminergic innervation, and increasing evidence suggests a key role of the locus coeruleus noradrenergic system (LC-NA). However, the difficulties in imaging LC-NA in patients challenge its direct investigation. To this end, we studied the development of tremor in a reserpinized rat model of PD, with or without a selective lesioning of LC-NA innervation with the neurotoxin DSP-4. Eight male rats (Sprague Dawley) received DSP-4 (50 mg/kg) two weeks prior to reserpine injection (10 mg/kg) (DR-group), while seven male animals received only reserpine treatment (R-group). Tremor, rigidity, hypokinesia, postural flexion and postural immobility were scored before and after 20, 40, 60, 80, 120 and 180 min of reserpine injection. Tremor was assessed visually and with accelerometers. The injection of DSP-4 induced a severe reduction in LC-NA terminal axons (DR-group: 0.024 ± 0.01 vs. R-group: 0.27 ± 0.04 axons/um\(^2\), p < 0.001) and was associated with significantly less tremor, as compared to the R-group (peak tremor score, DR-group: 0.5 ± 0.8 vs. R-group: 1.6 ± 0.5; p < 0.01). Kinematic measurement confirmed the clinical data (tremor consistency (\% of tremor during 180 s recording), DR-group: 37.9 ± 35.8 vs. R-group: 69.3 ± 29.6; p < 0.05). Akinetic-rigid symptoms did not differ between the DR- and R-groups. Our results provide preliminary causal evidence for a critical role of LC-NA innervation in the development of PD tremor and foster the development of targeted therapies for PD patients.},
  language  = {en}
}
@article{KremerPauwelsPozzietal.2021,
  author    = {Kremer, Naomi I. and Pauwels, Rik W. J. and Pozzi, Nicol{\`o} G. and Lange, Florian and Roothans, Jonas and Volkmann, Jens and Reich, Martin M.},
  title     = {Deep Brain Stimulation for Tremor: Update on Long-Term Outcomes, Target Considerations and Future Directions},
  series = {Journal of Clinical Medicine},
  volume    = {10},
  journal   = {Journal of Clinical Medicine},
  number    = {16},
  issn      = {2077-0383},
  doi       = {10.3390/jcm10163468},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-244982},
  year      = {2021},
  abstract  = {Deep brain stimulation (DBS) of the thalamic ventral intermediate nucleus is one of the main advanced neurosurgical treatments for drug-resistant tremor. However, not every patient may be eligible for this procedure. Nowadays, various other functional neurosurgical procedures are available. In particular cases, radiofrequency thalamotomy, focused ultrasound and radiosurgery are proven alternatives to DBS. Besides, other DBS targets, such as the posterior subthalamic area (PSA) or the dentato-rubro-thalamic tract (DRT), may be appraised as well. In this review, the clinical characteristics and pathophysiology of tremor syndromes, as well as long-term outcomes of DBS in different targets, will be summarized. The effectiveness and safety of lesioning procedures will be discussed, and an evidence-based clinical treatment approach for patients with drug-resistant tremor will be presented. Lastly, the future directions in the treatment of severe tremor syndromes will be elaborated.},
  language  = {en}
}
@article{MuellerGirardHopfneretal.2016,
  author    = {M{\"u}ller, Stefanie H. and Girard, Simon L. and Hopfner, Franziska and Merner, Nancy D. and Bourassa, Cynthia V. and Lorenz, Delia and Clark, Lorraine N. and Tittmann, Lukas and Soto-Ortolaza, Alexandra I. and Klebe, Stephan and Hallett, Mark and Schneider, Susanne A. and Hodgkinson, Colin A. and Lieb, Wolfgang and Wszolek, Zbigniew K. and Pendziwiat, Manuela and Lorenzo-Betancor, Oswaldo and Poewe, Werner and Ortega-Cubero, Sara and Seppi, Klaus and Rajput, Alex and Hussl, Anna and Rajput, Ali H. and Berg, Daniela and Dion, Patrick A. and Wurster, Isabel and Shulman, Joshua M. and Srulijes, Karin and Haubenberger, Dietrich and Pastor, Pau and Vilari{\~n}o-G{\"u}ell, Carles and Postuma, Ronald B. and Bernard, Genevi{\`e}ve and Ladwig, Karl-Heinz and Dupr{\´e}, Nicolas and Jankovic, Joseph and Strauch, Konstantin and Panisset, Michel and Winkelmann, Juliane and Testa, Claudia M. and Reischl, Eva and Zeuner, Kirsten E. and Ross, Owen A. and Arzberger, Thomas and Chouinard, Sylvain and Deuschl, G{\"u}nther and Louis, Elan D. and Kuhlenb{\"a}umer, Gregor and Rouleau, Guy A.},
  title     = {Genome-wide association study in essential tremor identifies three new loci},
  series = {Brain},
  volume    = {139},
  journal   = {Brain},
  doi       = {10.1093/brain/aww242},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-186541},
  pages     = {3163-3169},
  year      = {2016},
  abstract  = {We conducted a genome-wide association study of essential tremor, a common movement disorder characterized mainly by a postural and kinetic tremor of the upper extremities. Twin and family history studies show a high heritability for essential tremor. The molecular genetic determinants of essential tremor are unknown. We included 2807 patients and 6441 controls of European descent in our two-stage genome-wide association study. The 59 most significantly disease-associated markers of the discovery stage were genotyped in the replication stage. After Bonferroni correction two markers, one (rs10937625) located in the serine/threonine kinase STK32B and one (rs17590046) in the transcriptional coactivator PPARGC1A were associated with essential tremor. Three markers (rs12764057, rs10822974, rs7903491) in the cell-adhesion molecule CTNNA3 were significant in the combined analysis of both stages. The expression of STK32B was increased in the cerebellar cortex of patients and expression quantitative trait loci database mining showed association between the protective minor allele of rs10937625 and reduced expression in cerebellar cortex. We found no expression differences related to disease status or marker genotype for the other two genes. Replication of two lead single nucleotide polymorphisms of previous small genome-wide association studies (rs3794087 in SLC1A2, rs9652490 in LINGO1) did not confirm the association with essential tremor.},
  language  = {en}
}
@article{DelVecchioHanafiPozzietal.2023,
  author    = {Del Vecchio, Jasmin and Hanafi, Ibrahem and Pozzi, Nicol{\´o} Gabriele and Capetian, Philipp and Isaias, Ioannis U. and Haufe, Stefan and Palmisano, Chiara},
  title     = {Pallidal recordings in chronically implanted dystonic patients: mitigation of tremor-related artifacts},
  series = {Bioengineering},
  volume    = {10},
  journal   = {Bioengineering},
  number    = {4},
  issn      = {2306-5354},
  doi       = {10.3390/bioengineering10040476},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-313498},
  year      = {2023},
  abstract  = {Low-frequency oscillatory patterns of pallidal local field potentials (LFPs) have been proposed as a physiomarker for dystonia and hold the promise for personalized adaptive deep brain stimulation. Head tremor, a low-frequency involuntary rhythmic movement typical of cervical dystonia, may cause movement artifacts in LFP signals, compromising the reliability of low-frequency oscillations as biomarkers for adaptive neurostimulation. We investigated chronic pallidal LFPs with the Percept\(^{TM}\) PC (Medtronic PLC) device in eight subjects with dystonia (five with head tremors). We applied a multiple regression approach to pallidal LFPs in patients with head tremors using kinematic information measured with an inertial measurement unit (IMU) and an electromyographic signal (EMG). With IMU regression, we found tremor contamination in all subjects, whereas EMG regression identified it in only three out of five. IMU regression was also superior to EMG regression in removing tremor-related artifacts and resulted in a significant power reduction, especially in the theta-alpha band. Pallido-muscular coherence was affected by a head tremor and disappeared after IMU regression. Our results show that the Percept PC can record low-frequency oscillations but also reveal spectral contamination due to movement artifacts. IMU regression can identify such artifact contamination and be a suitable tool for its removal.},
  language  = {en}
}