Evaluation of Respiratory Muscle Activation Using Respiratory Motor Control Assessment (RMCA) in Individuals with Chronic Spinal Cord Injury

During breathing, activation of respiratory muscles is coordinated by integrated input from the brain, brainstem, and spinal cord. When this coordination ...

University of Louisville

We investigated autonomic control of cardiovascular function in able-bodied (AB), paraplegic (PARA), and tetraplegic (TETRA) subjects in response to head-up tilt following spinal cord injury. We evaluated spectral power of blood pressure (BP), baroreflex sensitivity (BRS), baroreflex effectiveness index (BEI), occurrence of systolic blood pressure (SBP) ramps, baroreflex sequences, and cross-correlation of SBP with heart rate (HR) in low (0.04-0.15 Hz)- and high (0.15-0.4 Hz)-frequency regions. During tilt, AB and PARA effectively regulated BP and HR, but TETRA did not. The numbers of SBP ramps and percentages of heartbeats involved in SBP ramps and baroreflex sequences increased in AB, were unchanged in PARA, and declined in TETRA. BRS was lowest in PARA and declined with tilt in all groups. BEI was greatest in AB and declined with tilt in all groups. Low-frequency power of BP and the peak of the SBP/HR cross-correlation magnitude were greatest in AB, increased during tilt in AB, remained unchanged in PARA, and declined in TETRA. The peak cross-correlation magnitude in HF decreased with tilt in all groups. Our data indicate that spinal cord injury results in decreased stimulation of arterial baroreceptors and less engagement of feedback control as demonstrated by lower 1) spectral power of BP, 2) number (and percentages) of SBP ramps and barosequences, 3) cross-correlation magnitude of SBP/HR, 4) BEI, and 5) changes in delay between SBP/HR. Diminished vasomotion and impaired baroreflex regulation may be major contributors to decreased orthostatic tolerance following injury.

Blood pressure regulation in neurally intact human vs. acutely injured paraplegic and tetraplegic patients during passive tilt.

Nous avons &eacute;tudi&eacute; le contr&ocirc;le autonome de la fonction cardiovasculaire aptes au travail (AB), parapl&eacute;gique (PARA) et sujets t&eacute;trapl&eacute;giques (TETRA) en r&eacute;ponse &agrave; l&#39;inclinaison de t&ecirc;te haute apr&egrave;s une blessure de la moelle &eacute;pini&egrave;re. Nous avons &eacute;valu&eacute; la puissance spectrale de pression art&eacute;rielle (PA), sensibilit&eacute; baror&eacute;flexe (SBR), indice de l&#39;efficacit&eacute; des baror&eacute;flexes (BEI), l&#39;occurrence des rampes de la pression art&eacute;rielle systolique (pas), les s&eacute;quences baror&eacute;flexe et la corr&eacute;lation crois&eacute;e de p&eacute;ritonite bact&eacute;rienne spontan&eacute;e avec la fr&eacute;quence cardiaque (FC) &agrave; faible (0,04-0.15 Hz)- et haute (0,15 &agrave; 0,4 Hz)-r&eacute;gions de fr&eacute;quence. Au cours de l&#39;inclinaison, AB et PARA r&eacute;glement&eacute;e efficacement BP et RH, mais TETRA n&#39;a pas. Le nombre de rampes SBP et pourcentages des impliqu&eacute;s dans les rampes SBP et s&eacute;quences baror&eacute;flexe a augment&eacute; en AB, battements de c&oelig;ur ont &eacute;t&eacute; inchang&eacute; en PARA et d&eacute;clin&eacute; en TETRA. BRS a &eacute;t&eacute; le plus bas en PARA et diminuent avec l&#39;inclinaison dans tous les groupes. BEI &eacute;tait le plus important en AB et diminue avec l&#39;inclinaison dans tous les groupes. Puissance de basse fr&eacute;quence de BP et le pic de la SBP/HR grandeur de corr&eacute;lation crois&eacute;e ont &eacute;t&eacute; plus grands AB, a augment&eacute; au cours de l&#39;inclinaison en AB, est rest&eacute; inchang&eacute; en PARA et a diminu&eacute; en TETRA. L&#39;amplitude de la corr&eacute;lation crois&eacute;e en HF a diminu&eacute; avec l&#39;inclinaison dans tous les groupes. Nos donn&eacute;es indiquent que la moelle &eacute;pini&egrave;re entra&icirc;ne des blessures une diminution stimulation des baror&eacute;cepteurs art&eacute;riels et moins l&#39;engagement de la commande de r&eacute;troaction, comme en t&eacute;moigne la plus faible puissance 1) spectrale de BP, 2) Num&eacute;ro (et les pourcentages) de rampes SBP et barosequences, grandeur 3) corr&eacute;lation crois&eacute;e de SBP/HR, BEI 4) et 5) variations de d&eacute;lai entre SBP/HR. diminu&eacute; la vasomotricit&eacute; et r&egrave;glement baror&eacute;flexe ayant une d&eacute;ficience peuvent &ecirc;tre des contributeurs majeurs &agrave; la tol&eacute;rance orthostatique diminu&eacute;e apr&egrave;s une blessure.

R&egrave;glement de tension art&eacute;rielle dans neurale intact homme vs patients parapl&eacute;giques et t&eacute;trapl&eacute;giques gravement bless&eacute;s pendant l&#39;inclinaison passive.

Abbiamo studiato controllo autonomico della funzione cardiovascolare in soggetti tetraplegici (TETRA) in risposta all&#39;head-up tilt dopo lesioni del midollo spinale, paraplegico (PARA) e normodotati (AB). Abbiamo valutato la potenza spettrale della pressione sanguigna (BP), sensibilit&agrave; baroreflex (BRS), indice di efficacia baroreflex (BEI), ricorrenza della pressione arteriosa sistolica (SBP) rampe, baroreflex sequenze e cross-correlazione di SBP con frequenza cardiaca (HR) in basso (0.04-0.15 Hz)- e alto (0.15-0.4 Hz)-regioni di frequenza. Durante il tilt, AB e PARA efficacemente regolamentati BP e HR, ma TETRA non ha fatto. I numeri di rampe SBP e percentuali di battiti cardiaci coinvolti nelle sequenze baroreflex aumentati in AB e rampe SBP erano invariato in PARA e declinato in TETRA. BRS era pi&ugrave; bassa in PARA e declin&ograve; con inclinazione in tutti i gruppi. BEI era pi&ugrave; grande in AB e declin&ograve; con inclinazione in tutti i gruppi. Bassa frequenza potenza di BP e il picco di SBP/HR cross-correlazione grandezza erano pi&ugrave; grande in AB, aumentato durante il tilt in AB, &egrave; rimasto invariato in PARA e declinato in TETRA. La grandezza di cross-correlazione di picco in HF diminuita con inclinazione in tutti i gruppi. I nostri dati indicano che risultati lesioni del midollo spinale in diminuita stimolazione dei barocettori arteriosi e meno impegno di controllo feedback come dimostrato dalla bassa potenza 1) spettrale di BP, 2) numero (e percentuali) di SBP rampe e barosequences, magnitudine 3) cross-correlazione di SBP/HR, (4) BEI e 5) modifiche in ritardo tra vasomotilit&agrave; SBP/h diminuita e baroreflex alterata regolazione possono essere maggiori contributori alla diminuita tolleranza ortostatica seguito di infortunio.

Sevda C. Aslan

Department of Neurological Surgery

University of Louisville

Evaluation of Respiratory Muscle Activation Using Respiratory Motor Control Assessment (RMCA) in Individuals with Chronic Spinal Cord Injury

Sevda C. Aslan

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Neurological Surgery

University of Louisville

Evaluation of Respiratory Muscle Activation Using Respiratory Motor Control Assessment (RMCA) in Individuals with Chronic Spinal Cord Injury

Department of Neurological Surgery