Autonomic nervous system disorders in stroke

Abstract

Disturbances of the autonomic nervous system are common in patients with various cerebrovascular diseases. They are attributed to damage of the central autonomic network, particularly in the frontoparietal cortical areas and in the brain stem, or to a disruption of the autonomic pathways descending from the hypothalamus via the mesencephalon, pons, and medulla to the spinal cord. The most common clinical problems include abnormalities in heart rate and blood pressure regulation, reflecting cardiovascular autonomic dysfunction, and asymmetric sweating with cold hemiplegic limbs, reflecting changes in the sudomotor and vasomotor regulatory systems. Bladder and bowel dysfunction and impotence are also frequent complaints after stroke, but the present knowledge concerning their prevalence and clinical significance is still limited. Cardiovascular autonomic dysfunction, which is mainly related to increased sympathetic activity, is most evident in the acute phase of stroke, whereas other autonomic disorders, such as abnormal sweating, are long-standing or even irreversible. In addition to the well-established sympathetic hyperfunction, abnormalities of the parasympathetic nervous system may also contribute to the autonomic imbalance after stroke. Reliable recognition of autonomic dysfunction using quantitative analysis methods is important, because these disturbances are not only subjectively disabling and uncomfortable, but they may also be prognostically unfavorable. Moreover, quantitative measurements also form the ground for successive treatment of various stroke-related autonomic disorders.

Stroke‐induced chronic systolic dysfunction driven by sympathetic overactivity

“…In the current study, 30‐minute tMCAO had an impact on autonomic regulation (see Fig 5), due to a direct lesion of the right insular cortex area (see Fig 1), or—in cases without macroscopic lesion detection—alternatively due to ischemic disruption of the autonomic pathways downstream of the insula that led to cardiac dysfunction development in comparison to left‐sided insular cortex lesions (see Fig 2). 44 As sympathetic overactivity is associated with myocardial injury and cardiac dysfunction up to heart failure development,40, 41, 43 it could be the missing link between IS and chronic cardiac dysfunction. In contrast to reports showing acute cardiac dysfunction after stroke,7 until now, no study has specifically investigated chronic development of systolic dysfunction after IS.…”

Application of the Sit-Up Test for orthostatic hypotension in individuals with stroke

“…It hasbeen suggested that clinically important OH is not common after stroke (Korpelainen et al, 1999) as it is with other populations, such as spinal cord injury or Parkinson's (Velseboer et al, 2011) where the clinical and health implications of OH is well established. However, with the combined occurrence of over 20% of participants demonstrating OH or hypotensive symptoms, we believe that orthostatic intolerance is prevalent and clinically important after stroke.…”

A Novel SPECT-Based Approach Reveals Early Mechanisms of Central and Peripheral Inflammation after Cerebral Ischemia

“…Translocation of gut bacteria after stroke has also been documented. [9][10][11] However, it is currently unclear whether brain injury has organ-specific effects, which could be revealed with imaging techniques in vivo.…”