| Description |
Multiple sclerosis (MS) is a chronic system autoimmune disease causing, on the basis of dissemination of demyelinisation focuses in CNS region, functional neurological deficit. The course is typically episodical, with acute attacks of demyelinisation occurring in irregular intervals and bringing about often increasing motor deficit and loss of sensoric functions (Havrdová, 2002). Dysfunctions of autonomic nervous system (ANS) are quite a frequent phenomenon in MS. They are characterized particularly by dysfunctions of urinary bladder, disorders of sexual and sudomotoric functions (Betts et al., 1994; Drory et al., 1995; elie et al., 1995). Autonomic dysfunctions affecting the cardiovascular system regulation, however, are also documented more and more frequently (e.g. Senaratne et al., 1984; nordenbo et al., 1989; Anema et al., 1991; Frontoni et al., 1993, 1996; Flachenecker et al., 1999; Acevedo et al., 2000; gunal et al., 2002; etc.). incidence of these dysfunctions varies as to frequency, importance of abnormities and autonomic reflex tests being used (Cartlige, 1972; pentland, ewing, 1987). Alterations of cardiovascular system parameters were demonstrated in MS patients both at rest and during physical load when AnS is responsible for compensation of hemodynamical cardiovascular response to physical stress. Autonomic dysfunctions can lead therefore to limitation of physical load capacity and can contribute to the fatigue of MS patients that has not yet been explained (Ziaber et al., 1997; Olindo et al., 2002; Konečný et al., 2007). It turns out that also subclinical manifestations of autonomic dysfunctions of cardiovascular regulation can become an unidentified risk factor with regard to farmacological and rehabilitation therapy of these patients. cardiovascular autonomic dysfunctions show also trend towards accentuation of clinical manifestations in consideration of the characteristic progression of MS disease. Diagnostics of autonomic dysfunctions, presenting themselves particularly on subclinical level, can be therefore a key element of preventive and curative strategy in the complex care of patients with this disease. Cardiovascular autonomic functions in MS are most frequently monitored by means of conventional reflex tests (Thomaides et al., 1993; Nasseri et al., 1998; Acevedo et al., 2000). These methods are limited mainly by difficult interpretation and differentiation of the sympathetic or parasympathetic component of cardiovascular regulation by autonomic nervous system. Heart rate variability (HRv) represents adaptation oscillation of heart rate values around its centre value. Distribution of these oscillations in specific frequency bands, from 0,02 Hz up to 0,50 Hz, expresses different mechanisms of acting on autonomic cardiovascular regulation. Spectral analysis of heart rate variability (SAHRV) offers a quick and non-invasive evaluation of the function of this regulation (Kautzner, Malik, 1998; Konečný et al., 2007; Pospíšil et al., 2004).
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