RESUMEN
OBJECTIVE: We focused on a rare gene mutation causing dystonia in two siblings who received globus pallidus internus deep brain stimulation (GPi-DBS). The aim was to characterize the relationship between neuronal activity patterns and clinical syndromes. METHODS: Whole exome sequencing was applied to identify the TWNK (previous symbol C10orf2) mutation; Two siblings with TWNK mutation presented as generalized dystonia with rigidity and bradykinesia; four other sporadic generalized dystonia patients underwent GPi-DBS and local field potentials (LFPs) were recorded. Oscillatory activities were illustrated with power spectra and temporal dynamics measured by the Lempel-Ziv complexity (LZC). RESULTS: Normalized power spectra of GPi LFPs differed between patients with TWNK mutation and dystonia over the low beta bands. Patients with TWNK mutation had higher low beta power (15-27 Hz, unpaired t-test, corrected P < 0.0022) and lower LZC (15-27 Hz, unpaired t-test, P < 0.01) than other patients with generalized dystonia. On the other hand, the TWNK mutation patients showed decreased low frequency and beta oscillation in the GPi after DBS, as well as improved movement performance. CONCLUSION: The LFPs were different in TWNK mutation dystonia siblings than other patients with generalized dystonia, which indicate the abnormal LFPs were related to symptoms rather than specific disease. In addition, the inhibited effect on oscillations also provided a potential evidence for DBS treatment on rare movement disorders. SIGNIFICANCE: This study could potentially aid in the future development of adaptive DBS via rare disease LFPs comparison.
Asunto(s)
Ritmo beta , ADN Helicasas/genética , Trastornos Distónicos/fisiopatología , Globo Pálido/fisiopatología , Proteínas Mitocondriales/genética , Adulto , Estimulación Encefálica Profunda , Trastornos Distónicos/genética , Trastornos Distónicos/patología , Trastornos Distónicos/terapia , Femenino , Globo Pálido/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Movimiento , Mutación , Secuenciación del ExomaRESUMEN
INTRODUCTION: Previous studies found subthalamic nucleus deep brain stimulation (STN-DBS) has clinical effect on Parkinson's disease, dystonia, and obsessive compulsive disorder. It is noteworthy that only a few studies report the STN-DBS for Tourette's syndrome (TS). Globus pallidus interna (GPi)-DBS is the one of the most common targets for TS. So, this paper aims to investigate the neural oscillations in STN and GPi as well as the DBS effect between these two targets in same patients. METHODS: The local field potentials (LFPs) were simultaneously recorded from the bilateral GPi and STN in four patients with TS. The LFPs were decomposed into neural oscillations, and the frequency and time-frequency characteristics of the neural oscillations were analyzed across the conditions of resting, poststimulation, and movement. RESULTS: No difference of resting LFP was found between the two targets. The poststimulation period spectral power revealed the high beta and gamma oscillations were recovered after GPi-DBS but remained attenuated after STN-DBS. The STN beta oscillation has fewer changes during tics than voluntary movement, and the gamma oscillation was elevated when the tics appeared. CONCLUSION: The high beta and gamma oscillations in GPi restored after GPi-DBS, but not STN-DBS. High beta and gamma oscillations may have physiological function in resisting tics in TS. The cortex compensation effect might be interfered by the STN-DBS due to the influence on the hyper-direct pathway but not GPi-DBS.
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Ondas Encefálicas/fisiología , Estimulación Encefálica Profunda , Globo Pálido/fisiopatología , Núcleo Subtalámico/fisiopatología , Síndrome de Tourette/terapia , Adulto , Humanos , Masculino , Movimiento/fisiología , Descanso , Síndrome de Tourette/fisiopatología , Adulto JovenRESUMEN
The aim of the present study was to examine whether there are changes in systolic and diastolic blood pressure (SBP and DBP) and heart rate (HR) and their spectral indices in conscious free-moving rats after tail-suspension for 28 d. The tail-suspended hindlimb-unloaded (HU) rat model was used to simulate the cardiovascular effect of microgravity and the post-spaceflight cardiovascular dysfunction. The auto- and cross-spectral analysis of SBP variability (SBPV) and HR variability (HRV) were performed by the method based on the autoregressive model (AR), and the auto-spectral results was compared with the results from the classical periodogram method. The baroreceptor-heart rate reflex sensitivity (BRS) was estimated using transfer function analysis from SBP to HR. The results indicated that auto-spectral results based on the two methods were comparable, while smoother power spectral curves with distinguished peaks were trained by the AR method. The means of SBP, DBP, and HR, the main spectral indices of SBPV and HRV, and the mean average gain of transfer functions computed at low- and high-frequency ranges (0.25-0.8 Hz and 0.8-2.4 Hz) did not show significant changes before and after release from suspension. Furthermore, the main spectral indices of SBPV and HRV at different time points did not show significant differences between the control and suspension groups. However, the means of SBP, DBP, and HR at different time points were significantly higher in simulated weightless rats than those in the control rats. The findings of the present study suggest that a mid-term simulated microgravity might induce hypertension and tachycardia upon removal from the suspension which reflects a general sympathetic hyperactivity. We speculated that the sympathetic hyperactivity might be a compensatory mechanism activated in the intact animal to counteract HU-induced hypo-responsiveness of resistance vessels. In addition, lack of clear and distinct changes in HRV and BRS have also been reported in some recent space and ground-based human studies.
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Presión Sanguínea , Frecuencia Cardíaca , Simulación de Ingravidez , Animales , Barorreflejo , Suspensión Trasera , Hipertensión , RatasRESUMEN
Although chronic pallidal deep brain stimulation (DBS) is effective in the treatment of medically intractable dystonia, there is no way of predicting the variations in clinical outcome, partly due to our limited understanding of the pathophysiological mechanisms underlying this condition. We recorded electromyographic (EMG) activity from the most severely affected muscle groups in seven dystonia patients before and after pallidal DBS. Patient EMG recordings could be classified into two groups: one consisting of patients who at rest demonstrated a dominant low frequency component of activity on power spectral analysis (ranging from 2 to 5 Hz), and one group in which this dominant pattern was absent. Early postoperative improvements (within 2-3 days) were observed in the former group, whereas the latter group benefited more gradually (over several months). Analysis of EMG activity may provide a sensitive means of identifying dystonic patients who are likely to be most responsive to functional neurosurgical intervention.
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Potenciales de Acción/fisiología , Distonía , Terapia por Estimulación Eléctrica/métodos , Electromiografía , Globo Pálido/efectos de la radiación , Músculo Esquelético/fisiopatología , Adulto , Anciano , Distonía/patología , Distonía/fisiopatología , Distonía/terapia , Femenino , Lateralidad Funcional/fisiología , Humanos , Masculino , Espectrometría de Masas , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Factores de TiempoRESUMEN
In order to investigate the dynamic change in transient neuromuscular events and the functional correlation between the neural and muscular activity, local field potentials (LFPs) of the subthalamic nucleus (STN) and surface electromyograms (sEMGs) over several episodes of transient resting tremor from a patient with Parkinson's disease were quantitatively characterised in time-frequency domain using short-time Fourier transform and continuous wavelet transform. Events of onset and cessation of the tremor-related activity in the STN and muscles were correlated to reveal the temporal relationship between the two signals. A significant suppression in the power of the STN LFPs in the beta band (10-30 Hz) preceded the onset of resting tremor, which was presented as the increases in the power at the tremor frequency (3.0-4.5 Hz) in both STN LFPs and surface EMGs. Over the episodes of the intermittent resting tremor, the power of the STN LFPs in the beta band and the power of sEMGs in the tremor frequency band change in an alternating pattern with a significant exponential correlation (P(STN) = 16.8+62.3 x exp(-P(EMG)/6270.7); R2 = 0.72; p < 0.05). Significant linear correlation in the power values at the tremor frequency appears between STN LFPs and sEMGs (P(STN) = 65.1 + 2.1 x 10(-4)P(EMG); R2 = 0.41; p < 0.05). In comparison with short-time Fourier transform, similar results could be achieved using continuous wavelet transform of an appropriate wavelet with a higher temporal resolution but larger distortion in the high frequency.
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Músculo Esquelético/fisiopatología , Enfermedad de Parkinson/fisiopatología , Núcleo Subtalámico/fisiopatología , Temblor/fisiopatología , Electromiografía , Antebrazo/fisiología , Análisis de Fourier , Humanos , Enfermedad de Parkinson/complicaciones , Factores de Tiempo , Temblor/etiologíaRESUMEN
In this study, we quantify the severity of drug-induced dyskinesias in the arms of Parkinson's disease (PD) patients using digitised spiral-drawing tasks. Two spiral drawings, namely a circular and a square spiral, are designed to, respectively, represent the continuous and discrete arm motions, and the size of the spiral is decided so that both the distal and proximal arm joints are involved. Fifteen PD patients, average disease duration 14.4+/-7.4 years, were assessed 30 min after a levodopa challenge whilst performing circular and square spiral-drawing tasks. The velocity of drawing movements was computed and the amplitude of the involuntary dyskinetic movements was measured as the standard deviation of the drawing velocity (SD-DV). The mean amplitude of dyskinetic movements was compared between arms and tasks and was correlated with clinical measures including the Bain dyskinesia scale and the total unified Parkinson's disease rating scale (UPDRS) score. The results showed that there was no statistically significant difference in the amplitude of dyskinesias either between the arms or between the continuous (circular) and discrete (square) spiral drawings in this group of PD patients, but interestingly the interaction between arm and drawing pattern was significant. Significant correlations were found between the magnitude of dyskinesia measured from the spiral-drawing tasks and both the 'on' or 'off' UPDRS and also the Bain dyskinesia scale. We conclude that the drawing tasks may be used to provide an objective method of quantifying the severity of drug-induced dyskinesias in the arm in PD patients.
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Antiparkinsonianos/efectos adversos , Brazo/fisiopatología , Discinesia Inducida por Medicamentos/etiología , Levodopa/efectos adversos , Desempeño Psicomotor/efectos de los fármacos , Adolescente , Adulto , Anciano , Evaluación de la Discapacidad , Humanos , Persona de Mediana Edad , Movimiento/fisiología , Examen Neurológico , Enfermedad de Parkinson/tratamiento farmacológico , Desempeño Psicomotor/fisiología , Índice de Severidad de la Enfermedad , Análisis EspectralRESUMEN
Application of coherence estimation needs not only to correctly estimate coherence values but also to efficiently test the statistical significance of the estimates. In the present report, we have explained the approach of optimising a coherence estimator by restricting its normalised bias error and random error. In addition to the commonly used independence threshold, two more tests based on the probability of detection and the exact confidence interval have been proposed for detecting the significance of the coherence estimates. All three methods have been used to evaluate the significant functional correlation between oscillatory field potentials (FPs) in the subthalamic nucleus (STN) and the surface electromyogram (EMG) of the forearm muscles during tremor in Parkinson's disease.
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Electrofisiología/métodos , Músculo Esquelético/fisiopatología , Enfermedad de Parkinson/diagnóstico , Procesamiento de Señales Asistido por Computador/instrumentación , Núcleo Subtalámico/fisiopatología , Temblor/diagnóstico , Potenciales de Acción/fisiología , Algoritmos , Relojes Biológicos/fisiología , Electromiografía/instrumentación , Electromiografía/métodos , Electrofisiología/instrumentación , Antebrazo/inervación , Antebrazo/fisiopatología , Humanos , Modelos Estadísticos , Contracción Muscular/fisiología , Músculo Esquelético/inervación , Neurofisiología/instrumentación , Neurofisiología/métodos , Enfermedad de Parkinson/fisiopatología , Reproducibilidad de los Resultados , Estadística como Asunto/instrumentación , Estadística como Asunto/métodos , Temblor/fisiopatologíaRESUMEN
The compound surface electromyograms (EMGs) recorded from patients with dystonia commonly contains superimposed bursting and tonic activity representing various motor symptoms. It is desirable to differentially extract them from the compound EMGs so that different symptoms can be more specifically investigated and different mechanisms revealed. A non-linear denoising approach based on wavelet transformation was investigated by applying soft thresholding to the wavelet coefficients. Thresholds were determined according to three different principles and two models. Different techniques for wavelet shrinkage were investigated for separating burst and tonic activity in the compound EMGs. The combination of Stein's unbiased risk estimate principle with a non-white noise model proved optimal for separating burst and tonic activity. These turned out to be exponentially related; and the temporal relationships between antagonist muscle contractions could now be seen clearly. We conclude that adaptive soft-thresholding wavelet shrinkage provides effective separation of burst and tonic activity in the compound EMG in dystonia. This separation should improve our understanding of the pathophysiology of dystonia.
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Potenciales de Acción/fisiología , Distonía/fisiopatología , Dinámicas no Lineales , Distonía/diagnóstico , Estimulación Eléctrica/métodos , Electromiografía/métodos , Humanos , Músculo Esquelético/fisiologíaRESUMEN
Heart rate variability (HRV) and blood pressure variability (BPV) reflect the modulation activity of autonomic nervous system on cardiovascular function. There have been important advances in multi-variate, multi-dimensional and dynamic analysis of HRV and BPV during recent years. Modern signal processing methods, such as multi-variate system identification, time-frequency analysis and nonlinear dynamics analysis, could be adopted in the risk prediction, severity evaluation and therapeutic treatment assessment of cardiovascular diseases. These new methods might also be useful in special environmental medicine.