Autonomic Dysreflexia Persists Following Acute Rehabilitation in Rats with Incomplete Contusive Spinal Cord Injury
Notice bibliographique
Résumé
Introduction Disruption of autonomic pathways following spinal cord injury (SCI) leads to altered cardiovascular (CV) function and homeostasis. The level and completeness of injury have great ramifications on the clinical presentation of CV pathology. Severe cervical and high thoracic lesions disrupt supraspinal control of sympathetic preganglionic neurons of the heart and upper body vasculature, leading to a state in which episodic hypertensive crises known as autonomic dysreflexia (AD) can develop. Rodent studies utilizing complete transection of the upper thoracic cord have shown that appropriately‐timed rehabilitation has the ability to reduce the severity of AD and normalize cardiac function. To date, no study has examined the impact of acute rehabilitation on CV function in a more clinically relevant contusive SCI model. Our objective was to evaluate the effects of either passive hind limb cycling (PHLC) or active swimming therapy on the development and severity of AD following severe T2 contusion. Methods Male Wistar rats with severe T2 contusions (400 kDyn, 5 second dwell, Infinite Horizons Impactor), were randomly divided into three groups: Control (T2‐CON, n=7), PHLC (T2‐ PHLC, n=5), or Swim rehabilitation (T2‐SWIM, n=6). A fourth group received T10 severe contusions and served as injured controls with intact cardiac sympathetic preganglionic pathways (T10‐CON, n=6). Rehabilitation therapy began 7 days post injury, and lasted for three weeks (30 minutes per day, 5 days per week). Five weeks post injury, rats were implanted with telemetric blood pressure devices (Millar, TRM54P) and pressor responses (i.e. AD) induced by colorectal distension (CRD) were evaluated. Results Resting hemodynamics did not differ between T2‐ PHLC, T2‐SWIM, and T2‐CON groups. Animals that received T10 injuries developed resting tachycardia (all groups p < .05). Pressor responses to CRD varied considerably across animals, but were significantly greater in T2 contused animals than in T10‐CON (all groups p < .05), and neither rehabilitation approach was able to attenuate the hypertensive crisis in response to CRD. However, if each group was subdivided based on BBB score, animals with low BBB scores (≤ 6) in the PHLC group were not statistically different from T10‐CON (p = .055). Conversely, both T2‐CON and T2‐SWIM animals with low BBB scores exhibited greater pressor responses during CRD (both groups p < .05). Conclusions Using a clinically relevant contusive model of SCI, we show that neither PHLC nor active swimming rehabilitation has the ability to favorably impact CV responses to CRD in incompletely injured T2 rats. However, if the most severely injured animals are assessed separately (BBB scores ≤ 6), PHLC appears to improve CV homeostasis and reduce the severity of pressor responses during CRD. This data suggests a relationship between locomotor recovery and CV function independent of applied PHLC or swim exercise that may depend more on improvements in hind limb activity and/or tissue sparing at the injury epicenter. Support or Funding Information iCORD VISIT Scholarship, CIHR, CNF, Kentucky Spinal Cord and Head Injury Trust (P30 RR031159), NIH (R56 NS052292), and Friends for Micheal
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,001 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,003 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».