A dominant bursting electromyograph pattern in dystonic conditions predicts an early response to pallidal stimulation.

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.

[Recent advances in multi-variate and multi-dimensional analysis of heart rate variability and blood pressure variability].

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.