ABSTRACT
A 10-year-old male with multiple sclerosis complained of excessive sweating on the right side of the forehead and shoulder on relapse 3 months after the onset of multiple sclerosis. Because the neurologic evaluation revealed no abnormalities in the sudomotor function, it is likely that the hyperhidrosis resulted from a lesion in the central or preganglionic sympathetic nervous system. Magnetic resonance imaging demonstrated a high-intensity lesion involving the left hypothalamus on T(2)-weighted imaging. Thus hypothalamic involvement might be the reason for the hyperhidrosis in this patient.
Subject(s)
Hyperhidrosis/etiology , Hypothalamus/pathology , Hypothalamus/physiopathology , Multiple Sclerosis/complications , Multiple Sclerosis/physiopathology , Abducens Nerve Diseases/etiology , Ataxia/etiology , Child , Diagnosis, Differential , Diplopia/etiology , Humans , Hyperhidrosis/physiopathology , Magnetic Resonance Imaging , Male , Paralysis/etiologyABSTRACT
A new technique for time series analysis, which is a combination of the maximum entropy method (MEM) for spectral analysis and the non-linear least squares method (LSM) for fitting analysis, is described. In this technique, the MEM power spectral density (MEMPSD) is calculated using a very large lag that could diminish the lag dependence of dominant periods estimated by the MEM analysis. The validity of this large lag is confirmed by the LSM, given that the ten dominant MEM periods are known quantities. To validate the MEM plus LSM technique, it is compared with autoregressive (AR) modelling, by analysing heart rate variability under pharmacological interventions (phenylephrine and trinitroglycerine), using 16 young males. The results indicate that the MEMPSD, when compared with the ARPSD, has numerous periods that could reproduce the original time series much more accurately, as revealed by the LSM analysis. However, both the low- and high-frequency powers with MEMPSD and ARPSDs shift in the expected directions in accordance with the pharmacological effects on the cardiovascular system. The implications of these results are discussed from the theoretical and practical standpoints of the MEM plus LSM technique, compared with AR modelling.