TY  - JOUR
A1  - Del Vecchio, Jasmin
A1  - Hanafi, Ibrahem
A1  - Pozzi, Nicoló Gabriele
A1  - Capetian, Philipp
A1  - Isaias, Ioannis U.
A1  - Haufe, Stefan
A1  - Palmisano, Chiara
T1  - Pallidal recordings in chronically implanted dystonic patients: mitigation of tremor-related artifacts
JF  - Bioengineering
N2  - 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.
KW  - dystonia
KW  - tremor
KW  - local field potentials
KW  - globus pallidus
KW  - deep brain stimulation
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-313498
SN  - 2306-5354
VL  - 10
IS  - 4
ER  - 
TY  - JOUR
A1  - Pozzi, Nicoló Gabriele
A1  - Bolzoni, Francesco
A1  - Biella, Gabriele Eliseo Mario
A1  - Pezzoli, Gianni
A1  - Ip, Chi Wang
A1  - Volkmann, Jens
A1  - Cavallari, Paolo
A1  - Asan, Esther
A1  - Isaias, Ioannis Ugo
T1  - Brain noradrenergic innervation supports the development of Parkinson’s tremor: a study in a reserpinized rat model
JF  - Cells
N2  - 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.
KW  - Parkinson’s disease
KW  - tremor
KW  - locus coeruleus
KW  - noradrenaline
KW  - reserpinized rat model
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357721
SN  - 2073-4409
VL  - 12
IS  - 21
ER  -