The link between stress disorders and autonomic dysfunction in muscular dystrophy

Abstract

Muscular dystrophy is a progressive disease of muscle weakness, muscle atrophy and cardiac dysfunction. Patients afflicted with muscular dystrophy exhibit autonomic dysfunction along with cognitive impairment, severe depression, sadness, and anxiety. Although the psychological aspects of cardiovascular disorders and stress disorders are well known, the physiological mechanism underlying this relationship is not well understood, particularly in muscular dystrophy. Therefore, the goal of this perspective is to highlight the importance of autonomic dysfunction and psychological stress disorders in the pathogenesis of muscular dystrophy. This article will for the first time-(i) outline autonomic mechanisms that are common to both psychological stress and cardiovascular disorders in muscular dystrophy; (ii) propose therapies that would improve behavioral and autonomic functions in muscular dystrophy.

Keywords: anxiety; baroreceptor reflex; depression; heart rate variability; neuromuscular disease; parasympathetic nervous system; sympathetic nervous system.

Figure 1

Possible mechanisms involved in autonomic dysfunction and psychological stress in muscular dystrophy. Sensory input by the baroreceptor afferents, cardiac vagal afferents, and skeletal muscle afferents are integrated within the brain to modulate parasympathetic and sympathetic outflows. Disturbances in the sensory inputs and/or central integration and neurotransmission may contribute to autonomic dysregulation and psychological stress in muscular dystrophy. SNA, sympathetic nerve activity; ParaSNA, parasympathetic nerve activity; RAS, renin angiotensin system; CRH, corticotrophin releasing hormone; HRV, heart rate variability; HR, heart rate; BRS, baroreflex sensitivity; (−), inhibition; (+), excitation.