| 1. |
- Bourke, Gráinne, et al.
(author)
-
Effects of early nerve repair on experimental brachial plexus injury in neonatal rats
- 2018
-
In: Journal of Hand Surgery, European Volume. - : Sage Publications. - 1753-1934 .- 2043-6289. ; 43:3, s. 275-281
-
Journal article (peer-reviewed)abstract
- Obstetrical brachial plexus injury refers to injury observed at the time of delivery, which may lead to major functional impairment in the upper limb. In this study, the neuroprotective effect of early nerve repair following complete brachial plexus injury in neonatal rats was examined. Brachial plexus injury induced 90% loss of spinal motoneurons and 70% decrease in biceps muscle weight at 28 days after injury. Retrograde degeneration in spinal cord was associated with decreased density of dendritic branches and presynaptic boutons and increased density of astrocytes and macrophages/microglial cells. Early repair of the injured brachial plexus significantly delayed retrograde degeneration of spinal motoneurons and reduced the degree of macrophage/microglial reaction but had no effect on muscle atrophy. The results demonstrate that early nerve repair of neonatal brachial plexus injury could promote survival of injured motoneurons and attenuate neuroinflammation in spinal cord.
|
|
| 2. |
- Bourke, Grainne, 1970-
(author)
-
Magnetic resonance imaging and diffusion tensor imaging after brachial plexus injury and repair : Experimental and clinical study
- 2022
-
Doctoral thesis (other academic/artistic)abstract
- Brachial plexus injuries (BPI) cause permanent upper limb paralysis and serious disability in adults and children. Timely identification of the severity of nerve injury and early appreciation of the inane potential for recovery would revolutionise management. Radiology supports clinical assessment but is not an independent marker of disease severity. Surgical evaluation in severe closed nerve injuries defines the reconstructive potential. This thesis explores aspects of BPI assessment and treatment that remain unsolved. Conventional magnetic resonance imaging (MRI) and novel diffusion tensor imaging (DTI) are evaluated in adults to gain a better understanding of their current diagnostic accuracy in BPI and future value in assessing nerve health. In neonates, this thesis evaluates the preganglionic effects related to timing of injury and repair and socioeconomic factors that influence the incidence and presentation of neonates to specialist centres. These currently controversial factors are important prerequisites to designing and evaluating the optimal objective imaging modality in this age group. Data from 29 high energy trauma BPI patients were analysed. The diagnostic accuracy of 1.5T MRI for BP root avulsion was 79% (Index test MRI, Reference standard Surgery). The negative predictive value was 81% meaning there was one occult avulsion in every 5 cases. DTI data sets from 12 patients with unilateral BPI and seven matched adult controls were acquired. The test was considered positive for root avulsion when there was a visible lack of continuity between tracts in the spinal cord and the brachial plexus. The mean fractional anisotropy (FA) and mean diffusivity (MD) were calculated from a region of interest (ROI) - five 2.5mm2 pixels in the axial plane covering the lateral recess of the vertebral foramen. The overall diagnostic accuracy of DTI for determining root avulsion was 71% (95%CI 54, 85). The fractional anisotropy (FA) of avulsed roots was 10% lower than normal roots (95% [CI 7%,13%] p<0.001). The mean diffusivity (MD) of avulsed roots was 0.32x10-3mm2/s higher than normal intact roots (95%CI 0.11, 0.53; p><0.001). The T1 tracts were not clearly visualised in most BPI cases. The time course comparing survival of motoneurons in a neonatal rat BPI model, was evaluated at 2- 28 days after injury and repair. At day 10, the injury group survival of motoneurons was 22% and at 28 days only 9%of motoneurons remained. In the repair group the surviving neurons were 51% at 10 days and 20% at 28 days. The repair group had significantly reduced reactivity of macrophages and microglial cells in the C5/C6 ventral horn. In analysis (Index of Multiple Deprivation, IMD) of a 13 year, retrospective cohort series of 321 children with Obstetric Brachial Plexus injury (England), 109 (39%) were from the most deprived quintile. In Yorkshire and Humber 44% were from the most deprived quintile. No relationship was identified between severity of condition and IMD. These laboratory and clinical studies in adults, children and neonatal animals align with the real-time clinical conundrum in evaluating the injured nerve’s ability to recover to functional significance. ><0.001). The mean diffusivity (MD) of avulsed roots was 0.32x10-3mm2/s higher than normal intact roots (95%CI 0.11, 0.53;p<0.001). The T1 tracts were not clearly visualised in most BPI cases. The time course comparing survival ofmotoneurons in a neonatal rat BPI model, was evaluated at 2- 28 days after injury and repair. At day 10, the injury group survival of motoneurons was 22% and at 28 days only 9%of motoneurons remained. In the repair group the surviving neurons were 51% at 10 days and 20% at 28 days. The repair group had significantly reduced reactivity of macrophages and microglial cells in the C5/C6 ventral horn. In analysis (Index of Multiple Deprivation, IMD) of a 13 year, retrospective cohort series of 321 children with Obstetric Brachial Plexus injury (England), 109 (39%) were from the most deprived quintile. In Yorkshire and Humber 44% were from the most deprived quintile. No relationship was identified between severity of condition and IMD. These laboratory and clinical studies in adults, children and neonatal animals align with the real-time clinical conundrum in evaluating the injured nerve’s ability to recover to functional significance.
|
|
| 3. |
- Hardie, Claire, et al.
(author)
-
Demographics and deprivation in obstetric brachial plexus palsy : a retrospective cohort study
- 2024
-
In: Journal of Hand Surgery, European Volume. - : Sage Publications. - 1753-1934 .- 2043-6289. ; 49:5, s. 570-575
-
Journal article (peer-reviewed)abstract
- The present study analyses the relationships between deprivation and obstetric brachial plexus palsy (OBPP). A retrospective observational study was conducted of infants with OBPP seen between 2008 and 2020 (n = 321). The index of multiple deprivation (IMD) was used to assign an IMD rank to patients based on birth postcode and the relationship with OBPP was analysed, including deprivation, gestational diabetes, age at referral and at first assessment. Quintile-based analysis demonstrated over-representation of patients from more deprived neighbourhoods (n = 109, 39%) living in the top 20% most deprived neighbourhoods. A total of 48 (15%) mothers had diabetes and 98 (31%) infants underwent surgical brachial plexus exploration (a marker of disease severity). Neither diabetes, age at referral nor age at first assessment were associated with IMD score. This suggests that neighbourhood deprivation is associated with OBPP, though the mechanisms are unclear. Further studies in this area may enable targeted health intervention for more deprived maternal and infant groups.
|
|
| 4. |
- Hardie, Claire, et al.
(author)
-
Diagnostic accuracy of magnetic resonance imaging for nerve injury in obstetric brachial plexus injury : protocol for systematic review and meta-analysis
- 2022
-
In: Systematic Reviews. - : BioMed Central. - 2046-4053. ; 11:1
-
Research review (peer-reviewed)abstract
- Background: Early and accurate clinical diagnosis of the extent of obstetric brachial plexus injury (OBPI) is challenging. The current gold standard for delineating the nerve injury is surgical exploration, and synchronous reconstruction is performed if indicated. Magnetic resonance imaging (MRI) is a non-invasive method of assessing the anatomy and severity of nerve injury in OBPI but the diagnostic accuracy is unclear. The primary objective of this review is to determine the diagnostic accuracy of MRI in comparison to surgical brachial plexus exploration for detecting root avulsion in children under 5 with OBPI. The secondary objectives are to determine its’ diagnostic accuracy for detecting nerve abnormality and detecting pseudomeningocele(s) in this group.Methods: This review will be conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA).We will include studies reporting the accuracy of MRI (index test) compared to surgical exploration (reference standard) in detecting any of the three target conditions (root avulsion, any nerve abnormality and pseudomeningocele) in children under five with OBPI. Case reports and studies where the number of true positives, false positives, true negatives and false negatives cannot be derived will be excluded. We plan to search PubMed, Embase and CENTRAL for relevant studies from database inception to 15 June 2022. We will also search grey literature (medRxiv, bioRxiv and Google Scholar) and perform forward and backward citation chasing. Screening and full-text assessment of eligibility will be conducted by two independent reviewers, who will then both extract the relevant data. The QUADAS-2 tool will be used to assess methodological quality and risk of bias of included studies by two reviewers independently. The following test characteristics for the target conditions will be extracted: true positives, false positives, true negatives and false negatives. Estimates of sensitivity and specificity with 95% confidence intervals will be shown in forest plots for each study. If appropriate, summary sensitivities and specificities for target conditions will be obtained via meta-analyses using a bivariate model.Discussion: This study will aim to clarify the diagnostic accuracy of MRI for detecting nerve injury in OBPI and define its clinical role. Systematic review registration: PROSPERO CRD42021267629.
|
|
| 5. |
- Hardie, C.M., et al.
(author)
-
Prevalence and risk factors for nerve injury following shoulder dislocation
- 2023
-
In: Musculoskeletal Surgery. - : Springer. - 2035-5106 .- 2035-5114. ; 107:3, s. 345-350
-
Journal article (peer-reviewed)abstract
- Background: The glenohumeral joint dislocation can be associated with major nerve injury. The reported prevalence and risk factors for major nerve injury are variable and this injury can have a severe and life-long impact on the patient. The objectives of this study were to analyse the prevalence of major nerve injury following shoulder dislocation and examine risk factors. Management and outcomes of nerve injury were explored.Methods: A 1 year retrospective cohort study of 243 consecutive adults who presented with a shoulder dislocation was performed. Data were collected on patient demographics, timings of investigations, treatment, follow-up, and nerve injury prevalence and management. The primary outcome measure was prevalence of nerve injury. Risk factors for this were analysed using appropriate tests with Stata SE15.1.Results: Of 243 patients with shoulder dislocation, 14 (6%) had neurological deficit. Primary dislocation (p = 0.004) and older age (p = 0.02) were significantly associated with major nerve injury. Sex, time to successful reduction and force of injury were not associated with major nerve injury in this cohort. Patients with nerve injury made functional recovery to varying degrees. Recurrent shoulder dislocation was common accounting for 133/243 (55%) attendances.Conclusions: Shoulder dislocation requires careful assessment and timely management in the ED. A 6% rate of nerve injury following shoulder dislocation was at the lower border of reported rates (5–55%), and primary dislocation and older age were identified as risk factors for nerve injury. We emphasise the importance of referring patients with suspected major nerve injury to specialist services.
|
|
| 6. |
- Jordan, Rupert, et al.
(author)
-
Functional deficits as a result of brachial plexus injury in anterior shoulder dislocation
- 2021
-
In: Journal of Hand Surgery, European Volume. - : Sage Publications. - 1753-1934 .- 2043-6289. ; 46:7, s. 725-730
-
Journal article (peer-reviewed)abstract
- The incidence of brachial plexus injuries in anterior shoulder dislocation remains relatively uncommon. A retrospective study was conducted to observe the natural neurological recovery of patients following these injuries over a 2-year period. Muscle power according to the Medical Research Council scale and sensation were measured from presentation to discharge. In 28 patients, the power grade of proximal muscles supplied by nine injured nerves failed to improve over a median follow-up of 5 months. There was no statistically significant improvement in sensation over a median follow-up of 6 months. Poorer recovery in muscle power score was related to advancing age, whereby every decade increased the risk by approximately 30%. Anterior shoulder dislocation with a plexus injury carries a risk of permanent nerve injury. Patients should be referred for specialist nerve assessment leading to rehabilitation and timely early nerve reconstruction, if indicated. Level of evidence: IV
|
|
| 7. |
- Jordan, Rupert, et al.
(author)
-
Re. Jordan R, Wade RG, McCauley G, Oxley S, Bains'R, Bourke G. Functional deficits as a result of brachial plexus injury in anterior shoulder dislocation.'J Hand Surg Eur. 2021, 46: 725-30 Reply
- 2022
-
In: Journal of Hand Surgery, European Volume. - : Sage Publications. - 1753-1934 .- 2043-6289. ; 47:8, s. 877-877
-
Journal article (other academic/artistic)
|
|
| 8. |
- Wade, Ryckie G., et al.
(author)
-
Diffusion Tensor Imaging for Diagnosing Root Avulsions in Traumatic Adult Brachial Plexus Injuries : A Proof-of-Concept Study
- 2020
-
In: Frontiers in Surgery. - : Frontiers Media S.A.. - 2296-875X. ; 7
-
Journal article (peer-reviewed)abstract
- Cross-sectional MRI has modest diagnostic accuracy for diagnosing traumatic brachial plexus root avulsions. Consequently, patients either undergo major exploratory surgery or months of surveillance to determine if and what nerve reconstruction is needed. This study aimed to develop a diffusion tensor imaging (DTI) protocol at 3 Tesla to visualize normal roots and identify traumatic root avulsions of the brachial plexus. Seven healthy adults and 12 adults with known (operatively explored) unilateral traumatic brachial plexus root avulsions were scanned. DTI was acquired using a single-shot echo-planar imaging sequence at 3 Tesla. The brachial plexus was visualized by deterministic tractography. Fractional anisotropy (FA) and mean diffusivity (MD) were calculated for injured and avulsed roots in the lateral recesses of the vertebral foramen. Compared to healthy nerves roots, the FA of avulsed nerve roots was lower (mean difference 0.1 [95% CI 0.07, 0.13]; p < 0.001) and the MD was greater (mean difference 0.32 × 10−3 mm2/s [95% CI 0.11, 0.53]; p < 0.001). Deterministic tractography reconstructed both normal roots and root avulsions of the brachial plexus; the negative-predictive value for at least one root avulsion was 100% (95% CI 78, 100). Therefore, DTI might help visualize both normal and injured roots of the brachial plexus aided by tractography. The precision of this technique and how it relates to neural microstructure will be further investigated in a prospective diagnostic accuracy study of patients with acute brachial plexus injuries.
|
|
| 9. |
- Wade, Ryckie G., et al.
(author)
-
Diffusion tensor imaging of the roots of the brachial plexus : a systematic review and meta-analysis of normative values
- 2020
-
In: Clinical and Transational Imaging. - : Springer. - 2281-5872 .- 2281-7565. ; 8, s. 419-431
-
Journal article (peer-reviewed)abstract
- Purpose: Diffusion tensor magnetic resonance imaging (DTI) characterises tissue microstructure and provides proxy measures of myelination, axon diameter, fibre density and organisation. This may be valuable in the assessment of the roots of the brachial plexus in health and disease. Therefore, there is a need to define the normal DTI values.Methods: The literature was systematically searched for studies of asymptomatic adults who underwent DTI of the brachial plexus. Participant characteristics, scanning protocols, and measurements of the fractional anisotropy (FA) and mean diffusivity (MD) of each spinal root were extracted by two independent review authors. Generalised linear modelling was used to estimate the effect of experimental conditions on the FA and MD. Meta-analysis of root-level estimates was performed using Cohen’s method with random effects.Results: Nine articles, describing 316 adults (1:1 male:female) of mean age 35 years (SD 6) were included. Increments of ten diffusion sensitising gradient directions reduced the mean FA by 0.01 (95% CI 0.01, 0.03). Each year of life reduced the mean MD by 0.03 × 10–3 mm2/s (95% CI 0.01, 0.04). At 3-T, the pooled mean FA of the roots was 0.36 (95% CI 0.34, 0.38; I2 98%). The pooled mean MD of the roots was 1.51 × 10–3 mm2/s (95% CI 1.45, 1.56; I2 99%).Conclusions: The FA and MD of the roots of the brachial plexus vary according to experimental conditions and participant factors. We provide summary estimates of the normative values in different conditions which may be valuable to researchers and clinicians alike.
|
|
| 10. |
- Wade, Ryckie G., et al.
(author)
-
Fractional anisotropy thresholding for deterministic tractography of the roots of the brachial plexus
- 2021
-
In: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 11:1
-
Journal article (peer-reviewed)abstract
- Diffusion tensor imaging (DTI) metrics, such as the fractional anisotropy (FA) and estimates of diffusivity are sensitive to the microstructure of peripheral nerves and may be displayed as tractograms. However, the ideal conditions for tractography of the roots of the brachial plexus are unclear, which represents the rationale for this study. Ten healthy adults were scanned using a Siemens Prisma (3T) and single-shot echo-planar imaging (b-value 0/1000 s/mm2, 64 directions, 2.5 mm3 with 4 averages; repeated in opposing phase encoding directions). Susceptibility correction and tractography were performed in DSI Studio by two independent raters. The effect of FA thresholding at increments of 0.01 (from 0.04 to 0.10) were tested. The mean FA varied between subjects by 2% (95% CI 1%, 3%). FA thresholds of 0.04, 0.05 and 0.06 all propagated 96% of tracts representing the roots; thresholding at 0.07 yielded 4% fewer tracts (p = 0.2), 0.08 yielded 11% fewer tracts (p = 0.008), 0.09 yielded 15% fewer tracts (p = 0.001) and 0.1 yielded 20% fewer tracts (p < 0.001). There was < 0.1% inter-rater variability in the measured FA and 99% agreement for tractography (κ = 0.92, p < 0.001). The fractional anisotropy thresholds required to generate tractograms of the roots of the brachial plexus appears to be lower than those used in the brain. We provide estimates of the probability of generating true tracts for each spinal nerve root of the brachial plexus, at different fractional anisotropy thresholds.
|
|
