Clinics in neurology and neurosurgery of sport: peripheral nerve injury

Intra and inter: Alterations in functional brain resting-state networks after peripheral nerve injury

INTRODUCTION

Numerous treatments suggest that brain plasticity changes after peripheral nerve injury (PNI), and most studies examining functional magnetic resonance imaging focused on abnormal changes in specific brain regions. However, it is the large-scale interaction of neuronal networks instead of isolated brain regions contributed to the functional recovery after PNI. In the present study, we examined the intra- and internetworks alterations between the related functional resting-state networks (RSNs) in a sciatic nerve injury rat model.

METHODS

Ninety-six female rats were divided into a control and model group. Unilateral sciatic nerve transection and direct anastomosis were performed in the latter group. We used an independent component analysis (ICA) algorithm to observe the changes in RSNs and assessed functional connectivity between different networks using the functional networks connectivity (FNC) toolbox.

RESULTS

Six RSNs related to PNI were identified, including the basal ganglia network (BGN), sensorimotor network (SMN), salience network (SN), interoceptive network (IN), cerebellar network (CN), and default mode network (DMN). The model group showed significant changes in whole-brain FC changes within these resting-state networks (RSNs), but four of these RSNs exhibited a conspicuous decrease. The interalterations performed that significantly decreased FNC existed between the BGN and SMN, BGN and IN, and BGN and DMN (p < .05, corrected). A significant increase in FNC existed between DMN and CN and between CN and SN (p < .05, corrected).

CONCLUSION

The results showed the large-scale functional reorganization at the network level after PNI. This evidence reveals new implications to the pathophysiological mechanisms in brain plasticity of PNI.

Epidemiology of Paediatric Shoulder Dislocation: A Nationwide Study in Italy from 2001 to 2014

Limited knowledge is accessible concerning the tendencies of hospitalization for skeletally immature patients with episodes of shoulder dislocation. Our research aim was to evaluate annual hospitalizations for shoulder dislocation in paediatric patients in Italy from 2001 to 2014, on the basis of the official data source as hospitalization reports. The second purpose was to investigate geographical diversification in hospitalization for shoulder dislocation in regions of Italy. The last aim was to make statistical predictions of the number of shoulder dislocation hospitalization volumes and rates in skeletally immature patients based on data from 2001 to 2014. An examination of the National Hospital Discharge records (SDO) kept at the Italian Ministry of Health regarding the 14 years of our study (2001 through 2014) was conducted. These data are anonymous and include patient's age, gender, domicile, region and time of hospitalization, and the kind of reimbursement (public or private). In the 14-year study time, 344 hospitalizations for shoulder dislocation of patients aged 0-14 years took place in Italy. The male/female hospitalization ratio varied from a maximum of 3.0 (2001) to a minimum of 1.1 (2013), with a mean average ratio in the 2001-2014 timespan of 2.0. Almost half of the hospitalizations (49.1%) were performed in the South. The mean incidence of hospitalizations in Italy for shoulder dislocation in patients with less than 14 years was 0.3 for every 100,000 inhabitants in the same class of age. The most common treatment was a closed reduction (60.8%), followed by open stabilization (16.6%) and arthroscopic procedures (13.7%). The present registry study shows a low incidence of hospitalization for shoulder dislocation in young patients. The most common treatment for a shoulder dislocation in paediatric patients is a closed shoulder reduction. Regions from the south and the centre of Italy are marked by an inferior number of operations and a higher number of hospitalization for closed shoulder reduction.

Variations in branching of the posterior cord of brachial plexus in a Kenyan population

Background

Variations in the branching of posterior cord are important during surgical approaches to the axilla and upper arm, administration of anesthetic blocks, interpreting effects of nervous compressions and in repair of plexus injuries. The patterns of branching show population differences. Data from the African population is scarce.

Objective

To describe the branching pattern of the posterior cord in a Kenyan population.

Materials and methods

Seventy-five brachial plexuses from 68 formalin fixed cadavers were explored by gross dissection. Origin and order of branching of the posterior cord was recorded. Representative photographs were then taken using a digital camera (Sony Cybershot ^R, W200, 7.2 Megapixels).

Results

Only 8 out of 75 (10.7%) posterior cords showed the classical branching pattern. Forty three (57.3%) lower subscapular, 8(10.3%) thoracodorsal and 8(10.3%) upper subscapular nerves came from the axillary nerve instead of directly from posterior cord. A new finding was that in 4(5.3%) and in 3(4%) the medial cutaneous nerves of the arm and forearm respectively originated from the posterior cord in contrast to their usual origin from the medial cord.

Conclusions

Majority of posterior cords in studied population display a wide range of variations. Anesthesiologists administering local anesthetic blocks, clinicians interpreting effects of nerve injuries of the upper limb and surgeons operating in the axilla should be aware of these patterns to avoid inadvertent injury. A wider study of the branching pattern of infraclavicular brachial plexus is recommended.