Severity of autonomic dysfunction in patients with complete spinal cord injury

Abstract

A complete loss of supraspinal control was observed in all, with a reflex isolated spinal cord in all but one patient. We confirm that in most SCI subjects there is concordance between the impairment of sympathetic function and somatic impairment. To assess autonomic dysfunction, a battery of tests should include SSR, abdominal electrical stimulation and Valsalva maneuver, as they combine pressor stimuli above and below the lesion and assess both cholinergic and sudomotor pathways.

Sympathetic Skin Responses and Autonomic Dysfunction in Spinal Cord Injury

“…Presumably, complete sensorimotor lesions (AIS A) above T1 would result in absent or abnormal palmar SSRs, as the palmar SSR is thought to originate at the T1-T3 levels. 10,25,47 Similarly, plantar SSRs would be absent in complete neurological injury above T10, with plantar SSRs generated between T10-L2. 10,25,47 Correspondingly, in those patients with complete neurological lesions below these levels, it would be expected to see preserved responses.…”

“…Previnaire et al 10 suggested that in order to fully characterize autonomic dysfunction in SCI, a battery of autonomic tests including SSRs, blood pressure response to Valsalva maneuver and response to perturbation below the lesion (i.e. with abdominal electrical stimulation) should be performed.…”

“…This is based on results showing discordance between sympathetic cholinergic and adrenergic tests, as some paraplegic subjects showed impaired blood pressure response to Valslava maneuver with preserved SSRs and vice versa. 10 Alternatively, the combination of SSRs with measurement of plasma catecholamines and power spectral analysis of SBP variability has been used to determine completeness of autonomic injury. 42,50 No study to date has measured the diagnostic utility of SSRs compared to other autonomic tests, such as the Autonomic Reflex Screen (encompassing measures of sudomotor, sympathetic adrenergic and cardiovagal function) developed by Low's group.…”

“…10 In this regard, sympathetic skin responses (SSRs), representing the integrity of the sympathetic cholinergic pathway to the sudomotor system, have emerged as a convenient, noninvasive measure of autonomic function in a range of conditions, including SCI. These responses have been used to better delineate the autonomic pathways affected by SCI and to quantify the magnitude of autonomic dysfunction in these patients.…”

Epileptic Seizure: A New Approach for Quantification of Autonomic Deregulation with Chaos Based Technique

“…Any signal, the spectrum may cover wide range of frequencies and conventional time and frequency domain analysis techniques based on the linear fluctuation of heart rate is insufficient to outline the changes in heart rate dynamics [25][26][27][28][29][30][31][32][33][34][35][36]. To quantify this, nonlinear dynamics based methods such as fractal analysis and chaos theory have been introduced [37][38][39]. These techniques have quite successfully been implemented on HR signals and provided significant clinical information on cardiac diseases [40][41][42][43][44][45], but are yet to be used on a few more fields like evaluation of autonomic cardiovascular dysfunction in epilepsy etc.…”