Cardiac dysfunctions are common complications following SCI. Cardiovascular disturbances are the leading causes of morbidity and mortality in both acute and chronic stages of SCI. We reviewed epidemiology of cardiac disturbances after SCI, and neuroanatomy and pathophysiology of autonomic nervous system, sympathetic and parasympathetic. SCI causes disruption of descendent pathways from central control centers to spinal sympathetic neurons, originating into intermediolateral nuclei of T1-L2 spinal cord segments. Loss of supraspinal control over sympathetic nervous system results in reduced overall sympathetic activity below the level of injury and unopposed parasympathetic outflow through intact vagal nerve. SCI associates significant cardiac dysfunction. Impairment of autonomic nervous control system, mostly in patients with cervical or high thoracic SCI, causes cardiac dysrrhythmias, especially bradycardia and, rarely, cardiac arrest, or tachyarrhytmias and hypotension. Specific complication dependent on the period of time after trauma like spinal shock and autonomic dysreflexia are also reviewed. Spinal shock occurs during the acute phase following SCI and is a transitory suspension of function and reflexes below the level of the injury. Neurogenic shock, part of spinal shock, consists of severe bradycardia and hypotension. Autonomic dysreflexia appears during the chronic phase, after spinal shock resolution, and it is a life-threatening syndrome of massive imbalanced reflex sympathetic discharge occurring in patients with SCI above the splanchnic sympathetic outflow (T5-T6). Besides all this, additional cardiac complications, such as cardiac deconditioning and coronary heart disease may also occur.
http://www.ncbi.nlm.nih.gov/pubmed/20108532
Neurogenic shock is
shock caused by the sudden loss of the
autonomic nervous system signals to the
smooth muscle in
vessel walls. This can result from severe
central nervous system (
brain and
spinal cord) damage. With the sudden loss of background
sympathetic stimulation, the vessels suddenly relax resulting in a sudden decrease in peripheral vascular resistance (
vasodilation)
[1] and
decreased blood pressure.
Signs and symptoms
Autoimmune autonomic ganglionopathy is characterized by impairment of multiple autonomic domains of which sudomotor function is among the most common. Many patients with this disorder have difficulties with thermoregulation and anhidrosis.
Sudomotor dysfunction in autoimmune autonomic ganglionopathy
http://www.ncbi.nlm.nih.gov/pubmed/19884578
Compensatory sweating remains the most common, and most disabling complication of video-assisted thoracoscopic sympathectomy. Other alternative more selective methods, rather than cutting the main trunk should be studied thoroughly to assess their efficacy in reducing the complication of compensatory sweating.
http://www.ncbi.nlm.nih.gov/pubmed/18521466
Surgical thoracic sympathectomy such as ESD or heart transplantation can result in an imbalance between the sympathetic and parasympathetic activities and result in functional changes
in the intrathoracic organs.
Therefore, the procedures affecting sympathetic nerve functions, such as epidural anesthesia, ESD, and heart transplantation, may cause an imbalance between sympathetic and parasympa-
thetic activities (1, 6, 16, 17). Recently, it has been reported that ESD results in functional changes of the intrathoracic organs.
In conclusion, our study demonstrated that ESD adversely affected lung function early after surgery and the BHR was affected by an imbalance of autonomic activity created by bilateral ESD in patients with primary focal hyperhidrosis.
Journal of Asthma, 46:276–279, 2009