Neuroimaging and electrophysiology efficacy in measuring acute effects and long-term sequelae following sports-related concussion

Traumatic brain injury (TBI) is a complex pathophysiological process resulting from external forces applied to the skull and affecting the brain. TBI is a significant global contributor to disability and death, particularly in children and young adults. The severity of a TBI may range from "mild" (a brief change in mental status or consciousness) to "severe" (an extended period of unconsciousness or amnesia after the injury), with mild TBI (mTBI) the most common form, diagnosed in 80-90% of cases. Sports-related concussion contributes significantly to mTBI accounting for nearly 20% of all mTBI cases. In the past decade there has been increasing growing public concern regarding the association of sports concussion; in particular further chance of recurrent injury following a concussion due to transient cognitive impairments, and long-term detrimental mental health issues and deterioration in brain function as a consequence of multiple concussions. Attention is also turning to methods to assess concussion with questions surrounding the reliability in traditional methods of concussion assessment that include symptom observation and cognitive assessment. This chapter will discuss the neuroscience of sports-related concussion, reviewing the evidence from new and rigorous methods of concussion assessment, such as neuroimaging and electrophysiology, with a focus on transcranial magnetic stimulation, following acute concussive events through tolong-term manifestations of multiple concussions.

ω-Conotoxin GVIA mimetics that bind and inhibit neuronal Cav2.2 ion channels

The neuronal voltage-gated N-type calcium channel (Ca_v2.2) is a validated target for the treatment of neuropathic pain. A small library of anthranilamide-derived ω-Conotoxin GVIA mimetics bearing the diphenylmethylpiperazine moiety were prepared and tested using three experimental measures of calcium channel blockade. These consisted of a ¹²⁵I-ω-conotoxin GVIA displacement assay, a fluorescence-based calcium response assay with SH-SY5Y neuroblastoma cells, and a whole-cell patch clamp electrophysiology assay with HEK293 cells stably expressing human Ca_v2.2 channels. A subset of compounds were active in all three assays. This is the first time that compounds designed to be mimics of ω-conotoxin GVIA and found to be active in the ¹²⁵I-ω-conotoxin GVIA displacement assay have also been shown to block functional ion channels in a dose-dependent manner.

Risk factors for impaired respiratory function during nurse-administered procedural sedation and analgesia in the cardiac catheterisation laboratory: a matched case-control study

Background
Side effects of the medications used for procedural sedation and analgesia in the cardiac catheterisation laboratory are known to cause impaired respiratory function. Impaired respiratory function poses considerable risk to patient safety as it can lead to inadequate oxygenation. Having knowledge about the conditions that predict impaired respiratory function prior to the procedure would enable nurses to identify at-risk patients and selectively implement intensive respiratory monitoring. This would reduce the possibility of inadequate oxygenation occurring.

Aim
To identify pre-procedure risk factors for impaired respiratory function during nurse-administered procedural sedation and analgesia in the cardiac catheterisation laboratory.

Design
Retrospective matched case–control.

Methods
21 cases of impaired respiratory function were identified and matched to 113 controls from a consecutive cohort of patients over 18 years of age. Conditional logistic regression was used to identify risk factors for impaired respiratory function.

Results
With each additional indicator of acute illness, case patients were nearly two times more likely than their controls to experience impaired respiratory function (OR 1.78; 95% CI 1.19–2.67; p = 0.005). Indicators of acute illness included emergency admission, being transferred from a critical care unit for the procedure or requiring respiratory or haemodynamic support in the lead up to the procedure.

Conclusion
Several factors that predict the likelihood of impaired respiratory function were identified. The results from this study could be used to inform prospective studies investigating the effectiveness of interventions for impaired respiratory function during nurse-administered procedural sedation and analgesia in the cardiac catheterisation laboratory.

Clinical practice guidelines for nurse-administered procedural sedation and analgesia in the cardiac catheterization laboratory: a modified Delphi study

Aim : To develop clinical practice guidelines for nurse-administered procedural sedation and analgesia in the cardiac catheterization laboratory.

Background : Numerous studies have reported that nurse-administered procedural sedation and analgesia is safe. However, the broad scope of existing guidelines for the administration and monitoring of patients who receive sedation during medical procedures without an anaesthetist present means there is a lack of specific guidance regarding optimal nursing practices for the unique circumstances where nurse-administered procedural sedation and analgesia is used in the cardiac catheterization laboratory.

Methods : A sequential mixed methods design was used. Initial recommendations were produced from three studies conducted by the authors: an integrative review; a qualitative study; and a cross-sectional survey. The recommendations were revised according to responses from a modified Delphi study. The first Delphi round was completed by nine senior cardiac catheterization laboratory nurses. All but one of the draft recommendations met the predetermined cut-off point for inclusion with 59 responses to the second round. Consensus was reached on all recommendations.

Implications for nursing : The guidelines that were derived from the Delphi study offer 24 recommendations within six domains of nursing practice: Pre-procedural assessment; Pre-procedural patient and family education; Pre-procedural patient comfort; Intra-procedural patient comfort; Intra-procedural patient assessment and monitoring; and Postprocedural patient assessment and monitoring.

Conclusion : These guidelines provide an important foundation towards the delivery of safe, consistent and evidence-based nursing care for the many patients who receive sedation in the cardiac catheterization laboratory setting.

Using transcranial magnetic stimulation to quantify electrophysiological changes following concussive brain injury: a systematic review

Mild traumatic brain injury (mTBI) and sports concussion are a growing public health concern, with increasing demands for more rigorous methods to quantify changes in the brain post-injury. Electrophysiology, and in particular, transcranial magnetic stimulation (TMS), have been demonstrated to provide prognostic value in a range of neurological conditions; however, no review has quantified the efficacy of TMS in mTBI/concussion. In the present study, we present a systematic review and critical evaluation of the scientific literature from 1990 to 2014 that has used TMS to investigate corticomotor excitability responses at short-term (< 12 months), medium-term (1-5 years), and long-term (> 5 years) post-mTBI/concussion. Thirteen studies met the selection criteria, with six studies presenting short-term changes, five studies presenting medium-term changes, and two studies presenting long-term changes. Irrespective of time post-concussion, change in intracortical inhibition was the most reported observation. Other findings included increased stimulation threshold, and slowed neurological conduction time. Although currently limited, the data suggest that TMS has prognostic value in detecting neurophysiological changes post-mTBI/concussion.