Articles: peripheral-nerve-injuries-physiopathology.
-
The injection of safe doses of botulinum neurotoxin A (BoNT/A) have been reported to be useful for the treatment of neuropathic pain, but it is still unknown how functional recovery is induced after peripheral nerve injury. We evaluated the effects of intranerve application of BoNT/A, on regeneration and sensorimotor functional recovery in partial and complete peripheral nerve injuries in the mouse. After sciatic nerve crush (SNC) and intranerve delivery of BoNT/A (15pg), axonal regeneration was measured by nerve pinch test at different days. ⋯ We observed also a higher expression of S100 in the distal portion of BoNT/A-injected regenerated nerves. In CCI mice, BoNT/A induced an increase in reinnervation of gastrocnemius and plantar muscles. These results show that a low dose of BoNT/A, insufficient to produce muscular dysfunction, conversely speeds up sensorimotor recovery by stimulating myelinated axonal regeneration, and points out its application as a multipotent treatment for peripheral neuropathies.
-
J. Cardiothorac. Vasc. Anesth. · Aug 2017
Observational StudyA Novel Automated Somatosensory Evoked Potential (SSEP) Monitoring Device for Detection of Intraoperative Peripheral Nerve Injury in Cardiac Surgery: A Clinical Feasibility Study.
Peripheral nerve injury (PNI) is a common and potentially devastating complication in cardiac surgery. Somatosensory evoked potential (SSEP) monitoring is one of the modalities for PNI; however, its application is limited by complicated logistics. This study aimed to assess the feasibility of using a novel, automated SSEP device (EPAD; SafeOp Surgical, Hunt Valley, MD) for detection of intraoperative PNI during cardiac surgery. ⋯ The EPAD automated SSEP device is a viable option for detecting PNI during cardiac surgery. A high incidence of intraoperative peripheral nerve compromise and a 6.1% incidence of postoperative peripheral neuropathy were observed. This study reports the clinical feasibility of using the EPAD automated SSEP device; additional studies are required to evaluate the diagnostic test accuracy and the outcome benefit of routine SSEP monitoring in cardiac surgical patients.
-
Opioids are the gold standard for pharmacological treatment of neuropathic pain, but their analgesic effects are unsatisfactory in part due to nerve injury-induced downregulation of opioid receptors in dorsal root ganglia (DRG) neurons. How nerve injury drives such downregulation remains elusive. DNA methyltransferase (DNMT)-triggered DNA methylation represses gene expression. ⋯ Mechanistically, DNMT3a regulation of Oprm1 gene expression required the methyl-CpG-binding protein 1, MBD1, as MBD1 knockout resulted in the decreased binding of DNMT3a to the Oprm1 gene promoter and blocked the DNMT3a-triggered repression of Oprm1 gene expression in DRG neurons. These data suggest that DNMT3a is required for nerve injury-induced and MBD1-mediated epigenetic silencing of the MOR and KOR in the injured DRG. DNMT3a inhibition may serve as a promising adjuvant therapy for opioid use in neuropathic pain management.
-
Regarding nerves as simple cables and electrical conduits is a gross error that does not allow us to understand the anomalies and disorders observed postoperatively. Instead, nerves should be seen as a living tissue of which physiological regulation is as complex as that of the blood-brain barrier. This review describes the basic structure and functions of this blood-nerve barrier and highlights the mechanisms of its breakdown and the resultant disorders. ⋯ This blood supply can adapt in a variety of ways but when these possibilities of adaptation are exceeded, tissue ischaemia may be more extensive. Also, even after the initial injury has subsided, inflammation can cause a secondary insult. This could be particularly important in some patients with subclinical neuropathy.
-
Journal of neurology · Mar 2017
Good prognosis of postpartum lower limb sensorimotor deficit: a combined clinical, electrophysiological, and radiological follow-up.
Postpartum lower limb motor and/or sensory deficit is an uncommon obstetrical complication. We aimed to identify its incidence, etiology, and precipitating factors, as well as the neurological prognosis by retrospectively analyzing the successive neurological evaluations, electrophysiological, and MRI data from all the consecutive patients with postpartum motor and/or sensory deficits of the lower limbs referred from the Lariboisière Obstetrical Department to the Lariboisière Neurophysiology Department, from January 2012 to June 2016, as well as data concerning labor and morphological characteristics of mother and baby. Thirteen patients (0.11% of the parturient women in the Lariboisière hospital) were included. ⋯ No other potentially precipitating factor was identified. Recovery was good in all patients, 7/11 (64%) made a rapid full recovery (mean recovery time 5 ± 2.5 weeks excluding one patient who had a normal neurological examination at 2 weeks but still complained of foot weakness that fully recovered in 1 year), and a minority (4/11, 36%) still complained of minor symptoms at time of follow-up, but showed marked improvement. New mothers presenting postpartum lower limb nerve injury should, therefore, be reassured.