Preserved cardiac autonomic dynamics during sleep in subjects with spinal cord injuries

Abstract

Spinal cord injuries (SCI) are associated with altered cardiovascular autonomic control. Sleep is characterized by modifications of autonomic control across sleep stages; however, no data are available on the effects of SCI on CAC during sleep. The aim of our study was to assess cariac autonomic modulation during sleep in SCI patients. Overnight polysomnographic recordings were obtained in 27 patients with cervical (Cerv) and thoracic (Thor) SCI and in healthy subjects (Controls). ECG and respiration were extracted from PSG, divided into sleep stages (W, N2, N3 and REM) for assessment of CAC, using symbolic analysis and Corrected Conditional Entropy. SA identifies three main indices, 0V%, index of sympathetic modulation, and 2LV% and 2UV%, markers of vagal modulation. CCE evaluates the complexity of heart period time series. Symbolic analysis revealed a reduction of 0V% in N2 and N3 compared to W and REM and an increase of 2LV% and 2UV% in N2 and N3 compared to W and REM in SCI patients, independent of the level of the lesion, and similar to Controls. Corrected Conditional Entropy was higher in N2 and N3 compared to W and REM in all three groups. In SCI patients, cardiac autonomic control changed across sleep stages, with a reduction of sympathetic and an increase of parasympathetic modulation during NREM compared to W and REM and a parallel increase of complexity during NREM, similar to Controls. Cardiac autonomic dynamics during sleep are maintained in SCI, independent of the level of the lesion.

Cardiac Autonomic Derangement Is Associated with Worse Neurological Outcome in the Very Early Phases of Ischemic Stroke

“…In our study, we performed two different kinds of analyses, i.e., a linear and a non–linear approach. No changes in autonomic modulation was found by classical spectral analysis; however, the symbolic analysis was more reliable in detecting changes of autonomic control in our population, as already shown in other studies [29,34,38]. Since a linear approach is based on the concept of “sympatho-vagal balance,” we can suppose that a non-linear analysis may be able to detect non-specular changes in the activity of the two branches, especially in acute clinical settings, characterized by the co-activation of several biological systems.…”

Cardiac autonomic dynamics during sleep are lost in patients with TIA and stroke

“…In fact, our data suggest that, independently from the size and location, ischaemic stroke or TIA are associated with a clear‐cut modification of cardiac autonomic control, with a completely absent modulation of HRV during sleep stages both in the acute and post‐acute phases. Such a negative impact on HRV seems to be peculiarity of ischaemic stroke and in contrast with experimental (sleep deprivation) and clinical conditions (myotonic dystrophy and spinal cord injuries), expected to be associated with vegetative alterations, which are accompanied by the conservation of HRV modulation during sleep (Tobaldini, Brugada et al., ; Tobaldini et al., ). Our results cannot exclude that such a loss of vegetative modulation precedes the ischaemic event, representing a risk factor for rather than a consequence of the ischaemic event, as suggested by previous studies (Binici, Mouridsen, Kober, & Sajadieh, ).…”

A review of sleep research in patients with spinal cord injury

“…Wijesuriya et al 5 Eight cSCI individuals and six able-bodied controls Choanal pressure recordings to assess awake nasal resistance Anterior rhinomanometry Fatima et al 6 22 cSCI individuals and 22 able-bodied controls Serum cortisol and melatonin sampling Tobaldini et al 7 12 cSCI individuals, 17 tSCI individual and eight able-bodied controls PSG, i.e. EEG; ECG; Chin EMG; Nasal airflow measurement Kostovski et al 8 Six cSCI individuals and six able-bodied controls Measurements of plasma melatonin and several hemostasis markers Proserpio et al 9 15 tetraplegic and 20 paraplegic individuals Clinical assessment PSG Arterial blood gas analysis Iversen et al 10 Six tetraplegic individuals and six ablebodied controls…”

“…The PSG studies 7,9,[11][12][13]15,16,20,28 show increased PLM and RLS levels, more sleep apnea and lowered oxygenation levels in individuals with SCI.…”