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ID 283 – EEG markers of motor activity in physiological aging and Alzheimer’s disease mouse models
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Abstracts / Clinical Neurophysiology 127 (2016) e18–e132
Results: The principle findings of this study were increase in mean kurtosis and decrease in mean diffusivity in thalamus, sensorimotor cortex, hippocampus, external capsule and basolateral amygdaloid nucleus in 14 month TNWT-61 mice as compared to WT littermates. We also found significant correlations between alpha-synuclein accumulation and increase in kurtosis and decrease in diffusivity in the thalamus. Conclusion: Our results reveal that DKI is sensitive in detecting microstructural changes due to alpha-synuclein accumulation in both GM and WM. These findings suggest that in PD patients DKI should be preferred to routine DTI despite a longer acquisition protocol. doi:10.1016/j.clinph.2015.11.225
respectively. Bilateral stimulation induced higher amplitudes compared with unilateral stimulation (p < 0.0001 for both reflexes). With age, VMR and AMR p1-peak latencies increased (VMR: F5,59 = 7.004, p < 0.0001; AMR: F5,59 = 3.265, p = 0.012) whereas only VMR amplitude decreased (F5,59 = 3.742, p = 0.003). The p1-peak latencies were shorter in females than males (VMR: p = 0.009; AMR: p = 0.002). Optimal thresholds were <113 dB for the AMR and >128 dB for the VMR. The zygomatic montage was associated to higher amplitudes (VMR: p = 0.034; AMR: p = 0.004). Conclusions: VMR and AMR behave similarly to commonly used myogenic potentials. Key message: Characterization of VMR and AMR in normal subjects adds value for their use in clinical settings where they are increasingly used to assess brainstem function. doi:10.1016/j.clinph.2015.11.227
ID 192 – Orthostatic tremor: A spectrum of fast and slow frequencies or distinct entities?—H. Rigby a,b, M.H. Rigby c, J. Caviness a (a Movement Disorders, Mayo Clinic, Scottsdale, USA, b Movement Disorders, Dalhousie University, Halifax, Canada, c Head and Neck Surgery, Dalhousie University, Halifax, Canada) Objective: Orthostatic tremor (OT) is defined by the presence of a high frequency (13–18 Hz) tremor of the legs on standing but some patients have discharge frequencies of. Methods: A retrospective review was performed on all subjects with a diagnosis of OT that were referred for confirmation by neurophysiology at the Mayo Clinic Arizona between 1999 and 2013. Results: Fourteen of 28 subjects (50%) had slow OT, of whom 8 had intermediate frequencies of. Conclusions: Slow tremor frequencies may characterize may characterize a substantial proportion of patients with OT. These subjects may have greater gait involvement and higher likelihood of falls. doi:10.1016/j.clinph.2015.11.226
ID 267 – Vestibulo-masseteric reflex and acoustic-masseteric reflex: Normative values—E.R. de Natale a, F. Ginatempo a, G. Pilurzi b, E. Ortu c, B. Mercante a, A. Manca a, I. Magnano b, E. Tolu a, J.C. Rothwell d, F. Deriu a (a Department of Biomedical Sciences, University of Sassari, Sassari, Italy, b Department of Clinical and Experimental Medicine, University of Sassari, Sassari, Italy, c Neurology Unit, A. Segni Hospital ASL 1 Sassari, Italy, d Institute of Neurology, University College London, London WC1N 3BG, United Kingdom) Objective: To provide normative values on the vestibulomasseteric (VMR) and acoustic-masseteric reflexes (AMR) for age/gender groups. Methods: Sixty healthy volunteers (27 males, 33 females; 45.817.4 years old), divided in 6 age groups (<25 years, 26–35, 36–45, 46–55, 56–65, >65 years), underwent click-evoked VMR (p11 wave) and AMR (p16/n21 wave). Zygomatic and mandibular electrode-montages and intensity-thresholds (98-138 dB SPL, at 5 dB intervals) were tested. Results: For unilateral stimulation, peak-latency values were: p11 = 11.42 ± 1.05 ms; p16 = 15.81 ± 1.22 ms; n21 = 20.58 ± 1.74. Corrected amplitudes were: p11 = 0.47 ± 0.18; p16/n21 = 0.49 ± 0.2. VMR and AMR were elicitable from 112/120 and 108/120 ears,
ID 283 – EEG markers of motor activity in physiological aging and Alzheimer’s disease mouse models—S. Lopez a, C. Del Percio b,c, J.F. Bastlund d, G. Forloni e, A. Frasca e, M. Bentivoglio f, P.F. Fabene f, G. Bertini f, J. Kelley g, S. Dix h, J.C. Richardson i, W. Drinkenburg h, C. Babiloni a,c (a Sapienza University of Rome, Italy, b University of Foggia, Italy, c IRCSS San Raffaele Pisana, Italy, d Lundbeck, Denmark, e IRCSS Mario Negri Institute, Italy, f University of Verona, Italy, g Janssen Pharmaceutica, Belgium, h Eli Lilly, UK, i Neurosciences Therapeutic Area U.K., United Kingdom) Objectives: In the framework of IMI PharmaCog project (Grant Agreement n°115009), we evaluated whether spectral electroencephalographic (EEG) markers of motor activity change across aging in wild type (WT) mice and in transgenic models of AD. Methods: All animal studies were carried out ethically (86/609/ EEC). EEG data were recorded from bipolar fronto-parietal electrode in 85 WT mice, 22 PDAPP, and 33 TASTPM mice. Artifact-free EEG segments during wake active and passive state (no sleep) were used as input for EEG power density analysis. Results: Statistical results (p < 0.05) showed: (1) higher 6–8 Hz power density during active state in the old (20–24 months) than the middle-aged (12–14 months) and young (4.5–6 months) WT mice, (2) higher 8–10 Hz power density during the active state in the young than in the middle-aged and old WT mice, (3) lower 2–6 Hz power density during the passive state in the TASTPM and PDAPP than in the WT mice, and (4) lower 8–10 Hz power density during the active state in the TASTPM and PDAPP than in the WT mice. Conclusions: EEG markers of motor activity are useful to unveil neurophysiological mechanisms of cortical neural synchronization characterizing the physiological and pathological aging in mice. doi:10.1016/j.clinph.2015.11.228
ID 368 – Regional changes in detrend fluctuation analysis exponent values in healthy subjects—L.M. James a,b, J. O’Kelly b (a BUPA Cromwell Hospital, Cromwell Road, London, UK, b Royal Hospital for Neuro-disability, Putney, UK) Objective: Detrended Fluctuation Analysis (DFA) was applied to EEGs recorded in healthy subjects as part of a study aimed at
Abstracts / Clinical Neurophysiology 127 (2016) e18–e132
Results: The principle findings of this study were increase in mean kurtosis and decrease in mean diffusivity in thalamus, sensorimotor cortex, hippocampus, external capsule and basolateral amygdaloid nucleus in 14 month TNWT-61 mice as compared to WT littermates. We also found significant correlations between alpha-synuclein accumulation and increase in kurtosis and decrease in diffusivity in the thalamus. Conclusion: Our results reveal that DKI is sensitive in detecting microstructural changes due to alpha-synuclein accumulation in both GM and WM. These findings suggest that in PD patients DKI should be preferred to routine DTI despite a longer acquisition protocol. doi:10.1016/j.clinph.2015.11.225
respectively. Bilateral stimulation induced higher amplitudes compared with unilateral stimulation (p < 0.0001 for both reflexes). With age, VMR and AMR p1-peak latencies increased (VMR: F5,59 = 7.004, p < 0.0001; AMR: F5,59 = 3.265, p = 0.012) whereas only VMR amplitude decreased (F5,59 = 3.742, p = 0.003). The p1-peak latencies were shorter in females than males (VMR: p = 0.009; AMR: p = 0.002). Optimal thresholds were <113 dB for the AMR and >128 dB for the VMR. The zygomatic montage was associated to higher amplitudes (VMR: p = 0.034; AMR: p = 0.004). Conclusions: VMR and AMR behave similarly to commonly used myogenic potentials. Key message: Characterization of VMR and AMR in normal subjects adds value for their use in clinical settings where they are increasingly used to assess brainstem function. doi:10.1016/j.clinph.2015.11.227
ID 192 – Orthostatic tremor: A spectrum of fast and slow frequencies or distinct entities?—H. Rigby a,b, M.H. Rigby c, J. Caviness a (a Movement Disorders, Mayo Clinic, Scottsdale, USA, b Movement Disorders, Dalhousie University, Halifax, Canada, c Head and Neck Surgery, Dalhousie University, Halifax, Canada) Objective: Orthostatic tremor (OT) is defined by the presence of a high frequency (13–18 Hz) tremor of the legs on standing but some patients have discharge frequencies of. Methods: A retrospective review was performed on all subjects with a diagnosis of OT that were referred for confirmation by neurophysiology at the Mayo Clinic Arizona between 1999 and 2013. Results: Fourteen of 28 subjects (50%) had slow OT, of whom 8 had intermediate frequencies of. Conclusions: Slow tremor frequencies may characterize may characterize a substantial proportion of patients with OT. These subjects may have greater gait involvement and higher likelihood of falls. doi:10.1016/j.clinph.2015.11.226
ID 267 – Vestibulo-masseteric reflex and acoustic-masseteric reflex: Normative values—E.R. de Natale a, F. Ginatempo a, G. Pilurzi b, E. Ortu c, B. Mercante a, A. Manca a, I. Magnano b, E. Tolu a, J.C. Rothwell d, F. Deriu a (a Department of Biomedical Sciences, University of Sassari, Sassari, Italy, b Department of Clinical and Experimental Medicine, University of Sassari, Sassari, Italy, c Neurology Unit, A. Segni Hospital ASL 1 Sassari, Italy, d Institute of Neurology, University College London, London WC1N 3BG, United Kingdom) Objective: To provide normative values on the vestibulomasseteric (VMR) and acoustic-masseteric reflexes (AMR) for age/gender groups. Methods: Sixty healthy volunteers (27 males, 33 females; 45.817.4 years old), divided in 6 age groups (<25 years, 26–35, 36–45, 46–55, 56–65, >65 years), underwent click-evoked VMR (p11 wave) and AMR (p16/n21 wave). Zygomatic and mandibular electrode-montages and intensity-thresholds (98-138 dB SPL, at 5 dB intervals) were tested. Results: For unilateral stimulation, peak-latency values were: p11 = 11.42 ± 1.05 ms; p16 = 15.81 ± 1.22 ms; n21 = 20.58 ± 1.74. Corrected amplitudes were: p11 = 0.47 ± 0.18; p16/n21 = 0.49 ± 0.2. VMR and AMR were elicitable from 112/120 and 108/120 ears,
ID 283 – EEG markers of motor activity in physiological aging and Alzheimer’s disease mouse models—S. Lopez a, C. Del Percio b,c, J.F. Bastlund d, G. Forloni e, A. Frasca e, M. Bentivoglio f, P.F. Fabene f, G. Bertini f, J. Kelley g, S. Dix h, J.C. Richardson i, W. Drinkenburg h, C. Babiloni a,c (a Sapienza University of Rome, Italy, b University of Foggia, Italy, c IRCSS San Raffaele Pisana, Italy, d Lundbeck, Denmark, e IRCSS Mario Negri Institute, Italy, f University of Verona, Italy, g Janssen Pharmaceutica, Belgium, h Eli Lilly, UK, i Neurosciences Therapeutic Area U.K., United Kingdom) Objectives: In the framework of IMI PharmaCog project (Grant Agreement n°115009), we evaluated whether spectral electroencephalographic (EEG) markers of motor activity change across aging in wild type (WT) mice and in transgenic models of AD. Methods: All animal studies were carried out ethically (86/609/ EEC). EEG data were recorded from bipolar fronto-parietal electrode in 85 WT mice, 22 PDAPP, and 33 TASTPM mice. Artifact-free EEG segments during wake active and passive state (no sleep) were used as input for EEG power density analysis. Results: Statistical results (p < 0.05) showed: (1) higher 6–8 Hz power density during active state in the old (20–24 months) than the middle-aged (12–14 months) and young (4.5–6 months) WT mice, (2) higher 8–10 Hz power density during the active state in the young than in the middle-aged and old WT mice, (3) lower 2–6 Hz power density during the passive state in the TASTPM and PDAPP than in the WT mice, and (4) lower 8–10 Hz power density during the active state in the TASTPM and PDAPP than in the WT mice. Conclusions: EEG markers of motor activity are useful to unveil neurophysiological mechanisms of cortical neural synchronization characterizing the physiological and pathological aging in mice. doi:10.1016/j.clinph.2015.11.228
ID 368 – Regional changes in detrend fluctuation analysis exponent values in healthy subjects—L.M. James a,b, J. O’Kelly b (a BUPA Cromwell Hospital, Cromwell Road, London, UK, b Royal Hospital for Neuro-disability, Putney, UK) Objective: Detrended Fluctuation Analysis (DFA) was applied to EEGs recorded in healthy subjects as part of a study aimed at