Combined Nerve and Tendon Transfers for C7-T1 Brachial Plexus Avulsion Injury.

BACKGROUND: In patients with C7-T1 brachial plexus avulsions, complete loss of hand function is commonly seen. However, the reconstruction of hand function is difficult. OBJECTIVE: To report the outcomes of hand function recovery after combined nerve and tendon transfers in C7-T1 brachial plexus injury. METHODS: From 2012 to 2019, 8 patients with C7-T1 brachial plexus injury underwent combined nerve and tendon transfers for hand function restoration, which included the following: (1) the pronator teres motor branch to the anterior interosseous nerve and brachialis motor branch to the flexor digitorum superficialis branch for finger flexion, (2) the supinator motor branch to the posterior interosseous nerve for finger extension, (3) the brachioradialis tendon transfer for thumb opposition, and (4) the radial branch of the superficial radial nerve to the sensory branch of the ulnar nerve for sensory reconstruction. Patients were evaluated for functional improvement of finger flexion, finger extension, thumb opposition, and sensory recovery. RESULTS: No clinical donor deficits were observed. Seven of eight patients recovered finger and thumb flexion (4 patients scored British Medical Research Council grade M4 and 3 scored M3). The average grip strength was 3.4 kg. All patients regained finger extension (4 scored M4 and 4 scored M3), thumb opposition, and protective sensation on the ulnar hand. Patients were able to use their reconstructed hands in daily lives. CONCLUSION: Combined nerve and tendon transfers are reliable and effective. This strategy could be an option for hand function reconstruction after C7-T1 brachial plexus injury.

3D printing-assisted percutaneous fixation makes the surgery for scaphoid nonunion more accurate and less invasive.

PURPOSE: The study was to explore whether the 3-dimensional printing guiding plate system could facilitate the modified procedure for arthroscopic treatment of nondisplaced scaphoid nonunion. METHODS: Patients, diagnosed with scaphoid nonunion without displacement, were randomly assigned into two groups. In Group A, the 3-dimensional printing guiding plate system was used for guiding fixation during the surgery. In Group B, fixation was performed with intra-operative fluoroscopy. The bone operation time was recorded during the surgery. The patients were evaluated before surgery and followed-up after six post-operative months, including motion ratio, strength ratio, Visual Analogue Scale, modified Mayo Scores, Patient Rated Wrist Evaluation scores, plain radiography and CT scan. RESULTS: Sixteen patients were recruited for the study. The average bone operation time in Group A was statistically shorter than that in Group B. CONCLUSIONS: 3-dimensional printing technique-assisted arthroscopic bone graft and fixation of scaphoid nonunion constitute an effective and accurate clinical treatment option. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: The concept and technique of 3D printing assisted percutaneous fixation introduced in this paper have the potential to be applied in a variety of operations requiring accurate percutaneous fixation, especially for the joint injuries.

Stability of motor endplates is greater in the biceps than in the interossei in a rat model of obstetric brachial plexus palsy.

The time window for repair of the lower trunk is shorter than that of the upper trunk in patients with obstetric brachial plexus palsy. The denervated intrinsic muscles of the hand become irreversibly atrophic much faster than the denervated biceps. However, it is unclear whether the motor endplates of the denervated interosseous muscles degenerate more rapidly than those of the denervated biceps. In this study, we used a rat model of obstetric brachial plexus palsy of the right upper limb. C5-6 was lacerated distal to the intervertebral foramina, with concurrent avulsion of C7-8 and T1, with the left upper limb used as the control. Bilateral interossei and biceps were collected at 5 and 7 weeks. Immunofluorescence was used to assess the morphology of the motor endplates. Real-time quantitative polymerase chain reaction and western blot assay were used to assess mRNA and protein expression levels of acetylcholine receptor subunits (α, ß and δ), rapsyn and ß-catenin. Immunofluorescence microscopy showed that motor endplates in the denervated interossei were fragmented, while those in the denervated biceps were morphologically intact with little fragmentation. The number and area of motor endplates, relative to the control side, were significantly lower in the denervated interossei compared with the denervated biceps. mRNA and protein expression levels of acetylcholine receptor subunits (α, ß and δ) were significantly lower, whereas ß-catenin protein expression was higher, in the denervated interossei compared with the denervated biceps. The protein expression of rapsyn was higher in the denervated biceps than in the denervated interossei at 7 weeks. Our findings demonstrate that motor endplates of interossei are destabilized, whereas those of the biceps remain stable, in the rat model of obstetric brachial plexus palsy. All procedures were approved by the Experimental Animal Ethics Committee of Fudan University, China (approval No. DF-187) in January 2016.

Inflammation and apoptosis accelerate progression to irreversible atrophy in denervated intrinsic muscles of the hand compared with biceps: proteomic analysis of a rat model of obstetric brachial plexus palsy.

In treating patients with obstetric brachial plexus palsy, we noticed that denervated intrinsic muscles of the hand become irreversibly atrophic at a faster than denervated biceps. In a rat model of obstetric brachial plexus palsy, denervated intrinsic musculature of the forepaw entered the irreversible atrophy far earlier than denervated biceps. In this study, isobaric tags for relative and absolute quantitation were examined in the intrinsic musculature of forepaw and biceps on denervated and normal sides at 3 and 5 weeks to identify dysregulated proteins. Enrichment of pathways mapped by those proteins was analyzed by Kyoto Encyclopedia of Genes and Genomes analysis. At 3 weeks, 119 dysregulated proteins in denervated intrinsic musculature of the forepaw were mapped to nine pathways for muscle regulation, while 67 dysregulated proteins were mapped to three such pathways at 5 weeks. At 3 weeks, 27 upregulated proteins were mapped to five pathways involving inflammation and apoptosis, while two upregulated proteins were mapped to one such pathway at 5 weeks. At 3 and 5 weeks, 53 proteins from pathways involving regrowth and differentiation were downregulated. At 3 weeks, 64 dysregulated proteins in denervated biceps were mapped to five pathways involving muscle regulation, while, five dysregulated proteins were mapped to three such pathways at 5 weeks. One protein mapped to inflammation and apoptotic pathways was upregulated from one pathway at 3 weeks, while three proteins were downregulated from two other pathways at 5 weeks. Four proteins mapped to regrowth and differentiation pathways were upregulated from three pathways at 3 weeks, while two proteins were downregulated in another pathway at 5 weeks. These results implicated inflammation and apoptosis as critical factors aggravating atrophy of denervated intrinsic muscles of the hand during obstetric brachial plexus palsy. All experimental procedures and protocols were approved by the Experimental Animal Ethics Committee of Fudan University, China (approval No. DF-325) in January 2015.

Transfers of the Ipsilateral C7 Plus the Spinal Accessory Nerve Versus Triple Nerve Transfers for Treatment of C5-C6 Avulsion of the Brachial Plexus.

PURPOSE: To compare the long-term results of transfers of the ipsilateral C7 (IC7) plus spinal accessory nerve (SAN) with those of triple nerve transfers (TNT) using one fascicle of the ulnar nerve to the biceps motor branch (Oberlin's procedure), SAN transferred to the suprascapular nerve, and transfer of the long head of triceps nerve branch to the anterior branch of axillary nerve to treat C5-C6 avulsion of the brachial plexus. METHODS: The IC7 group included 9 patients undergoing transfers of IC7 to the upper trunk and SAN to the suprascapular nerve. Median age at surgery was 26 years and interval between injury and surgery was 2.8 months. Patients were observed for a median of 118 months. The TNT group contained 13 patients, median age 33 years; interval between injury and surgery was 3.1 months. Patients were observed for a median of 103 months. RESULTS: In the IC7 group, median shoulder abduction was 105° and median external rotation of the shoulder was 64°, which was similar to that of the TNT group (89° abduction and 58° external rotation). Eight of nine patients recovered at least M3 (Modified Narakas scale) strength of deltoid in the IC7 group, which was similar to that in the TNT group (11 of 13 patients). Six of nine patients achieved at least Medical Research Council grade 3 (MRC3) strength of biceps in the IC7 group, which was similar to that in the TNT group (11 of 13 patients). Of 4 patients in the IC7 group with a preoperative latissimus dorsi strength of MRC3 or less, 3 gained a deltoid strength of M3 or less, and 3 a biceps strength of MRC2 or less. CONCLUSIONS: Transfers of IC7 plus SAN provide results comparable to those of TNT for treatment of C5-C6 avulsion. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Surgical treatment for severe cubital tunnel syndrome with absent sensory nerve conduction.

For severe cubital tunnel syndrome, patients with absent sensory nerve action potential tend to have more severe nerve damage than those without. Thus, it is speculated that such patients generally have a poor prognosis. How absent sensory nerve action potential affects surgical outcomes remains uncertain owing to a scarcity of reports and conflicting results. This retrospective study recruited one hundred and fourteen cases (88 patients with absent sensory nerve action potential and 26 patients with present sensory nerve action potential) undergoing either subcutaneous transposition or in situ decompression. The minimum follow-up was set at 2 years. Primary outcome measures of overall hand function included their McGowan grade, modified Bishop score, and Disabilities of the Arm, Shoulder, and Hand Questionnaire (DASH) score. For patients with absent sensory nerve action potential, 71 cases (80.7%) achieved at least one McGowan grade improvement, 76 hands (86.4%) got good or excellent results according to the Bishop score, and the average DASH score improved 49.5 points preoperatively to 13.1 points postoperatively. When compared with the present sensory nerve action potential group, they showed higher postoperative McGowan grades and DASH scores, but there was no statistical difference between the modified Bishop scores of the two groups. Following in situ decompression or subcutaneous transposition, great improvement in hand function was achieved for severe cubital tunnel syndrome patients with absent sensory nerve action potential. The functional outcomes after surgery for severe cubital tunnel syndrome are worse in patients with absent sensory nerve action potential than those without. This study was approved by the Ethical Committee of Huashan Hospital, Fudan University, China (approval No. 2017142).

Endogenous automatic nerve discharge promotes nerve repair: an optimized animal model.

Exogenous electrical nerve stimulation has been reported to promote nerve regeneration. Our previous study has suggested that endogenous automatic nerve discharge of the phrenic nerve and intercostal nerve has a positive effect on nerve regeneration at 1 month postoperatively, but a negative effect at 2 months postoperatively, which may be caused by scar compression. In this study, we designed four different rat models to avoid the negative effect from scar compression. The control group received musculocutaneous nerve cut and repair. The other three groups were subjected to side-to-side transfer of either the phrenic (phrenic nerve group), intercostal (intercostal nerve group) or thoracodorsal nerves (thoracic dorsal nerve group), with sural nerve autograft distal to the anastomosis site. Musculocutaneous nerve regeneration was assessed by electrophysiology of the musculocutaneous nerve, muscle tension, muscle wet weight, maximum cross-sectional area of biceps, and myelinated fiber numbers of the proximal and distal ends of the anastomosis site of the musculocutaneous nerve and the middle of the nerve graft. At 1 month postoperatively, compound muscle action potential amplitude of the biceps in the phrenic nerve group and the intercostal nerve group was statistically higher than that in the control group. The myelinated nerve fiber numbers in the distal end of the musculocutaneous nerve and nerve graft anastomosis in the phrenic nerve and the intercostal nerve groups were statistically higher than those in the control and thoracic dorsal nerve groups. The neural degeneration rate in the middle of the nerve graft in the thoracic dorsal nerve group was statistically higher than that in the phrenic nerve and the intercostal nerve groups. At 2 and 3 months postoperatively, no significant difference was detected between the groups in all the assessments. These findings confirm that the phrenic nerve and intercostal nerve have a positive effect on nerve regeneration at the early stage of recovery. This study established an optimized animal model in which suturing the nerve graft to the distal site of the musculocutaneous nerve anastomosis prevented the inhibition of recovery from scar compression.

Contralateral C7 to C7 nerve root transfer in reconstruction for treatment of total brachial plexus palsy: anatomical basis and preliminary clinical results.

OBJECTIVEContralateral C7 (CC7) nerve root has been used as a donor nerve for targeted neurotization in the treatment of total brachial plexus palsy (TBPP). The authors aimed to study the contribution of C7 to the innervation of specific upper-limb muscles and to explore the utility of C7 nerve root as a recipient nerve in the management of TBPP.METHODSThis was a 2-part investigation. 1) Anatomical study: the C7 nerve root was dissected and its individual branches were traced to the muscles in 5 embalmed adult cadavers bilaterally. 2) Clinical series: 6 patients with TBPP underwent CC7 nerve transfer to the middle trunk of the injured side. Outcomes were evaluated with the modified Medical Research Council scale and electromyography studies.RESULTSIn the anatomical study there were consistent and predominantly C7-derived nerve fibers in the lateral pectoral, thoracodorsal, and radial nerves. There was a minor contribution from C7 to the long thoracic nerve. The average distance from the C7 nerve root to the lateral pectoral nerve entry point of the pectoralis major was the shortest, at 10.3 ± 1.4 cm. In the clinical series the patients had been followed for a mean time of 30.8 ± 5.3 months postoperatively. At the latest follow-up, 5 of 6 patients regained M3 or higher power for shoulder adduction and elbow extension. Two patients regained M3 wrist extension. All regained some wrist and finger extension, but muscle strength was poor. Compound muscle action potentials were recorded from the pectoralis major at a mean follow-up of 6.7 ± 0.8 months; from the latissimus dorsi at 9.3 ± 1.4 months; from the triceps at 11.5 ± 1.4 months; from the wrist extensors at 17.2 ± 1.5 months; from the flexor carpi radialis at 17.0 ± 1.1 months; and from the digital extensors at 22.8 ± 2.0 months. The average sensory recovery of the index finger was S2. Transient paresthesia in the hand on the donor side, which resolved within 6 months postoperatively, was reported by all patients.CONCLUSIONSThe C7 nerve root contributes consistently to the lateral pectoral nerve, the thoracodorsal nerve, and long head of the triceps branch of the radial nerve. CC7 to C7 nerve transfer is a reconstructive option in the overall management plan for TBPP. It was safe and effective in restoring shoulder adduction and elbow extension in this patient series. However, recoveries of wrist and finger extensions are poor.

Phrenic and intercostal nerves with rhythmic discharge can promote early nerve regeneration after brachial plexus repair in rats.

Exogenous discharge can positively promote nerve repair. We, therefore, hypothesized that endogenous discharges may have similar effects. The phrenic nerve and intercostal nerve, controlled by the respiratory center, can emit regular nerve impulses; therefore these endogenous automatically discharging nerves might promote nerve regeneration. Action potential discharge patterns were examined in the diaphragm, external intercostal and latissimus dorsi muscles of rats. The phrenic and intercostal nerves showed rhythmic clusters of discharge, which were consistent with breathing frequency. From the first to the third intercostal nerves, spontaneous discharge amplitude was gradually increased. There was no obvious rhythmic discharge in the thoracodorsal nerve. Four animal groups were performed in rats as the musculocutaneous nerve cut and repaired was bland control. The other three groups were followed by a side-to-side anastomosis with the phrenic nerve, intercostal nerve and thoracodorsal nerve. Compound muscle action potentials in the biceps muscle innervated by the musculocutaneous nerve were recorded with electrodes. The tetanic forces of ipsilateral and contralateral biceps muscles were detected by a force displacement transducer. Wet muscle weight recovery rate was measured and pathological changes were observed using hematoxylin-eosin staining. The number of nerve fibers was observed using toluidine blue staining and changes in nerve ultrastructure were observed using transmission electron microscopy. The compound muscle action potential amplitude was significantly higher at 1 month after surgery in phrenic and intercostal nerve groups compared with the thoracodorsal nerve and blank control groups. The recovery rate of tetanic tension and wet weight of the right biceps were significantly lower at 2 months after surgery in the phrenic nerve, intercostal nerve, and thoracodorsal nerve groups compared with the negative control group. The number of myelinated axons distal to the coaptation site of the musculocutaneous nerve at 1 month after surgery was significantly higher in phrenic and intercostal nerve groups than in thoracodorsal nerve and negative control groups. These results indicate that endogenous autonomic discharge from phrenic and intercostal nerves can promote nerve regeneration in early stages after brachial plexus injury.

Trial of Contralateral Seventh Cervical Nerve Transfer for Spastic Arm Paralysis.

BACKGROUND: Spastic limb paralysis due to injury to a cerebral hemisphere can cause long-term disability. We investigated the effect of grafting the contralateral C7 nerve from the nonparalyzed side to the paralyzed side in patients with spastic arm paralysis due to chronic cerebral injury. METHODS: We randomly assigned 36 patients who had had unilateral arm paralysis for more than 5 years to undergo C7 nerve transfer plus rehabilitation (18 patients) or to undergo rehabilitation alone (18 patients). The primary outcome was the change from baseline to month 12 in the total score on the Fugl-Meyer upper-extremity scale (scores range from 0 to 66, with higher scores indicating better function). Results The mean increase in Fugl-Meyer score in the paralyzed arm was 17.7 in the surgery group and 2.6 in the control group (difference, 15.1; 95% confidence interval, 12.2 to 17.9; P<0.001). With regard to improvements in spasticity as measured on the Modified Ashworth Scale (an assessment of five joints, each scored from 0 to 5, with higher scores indicating more spasticity), the smallest between-group difference was in the thumb, with 6, 9, and 3 patients in the surgery group having a 2-unit improvement, a 1-unit improvement, or no change, respectively, as compared with 1, 6, and 7 patients in the control group (P=0.02). Transcranial magnetic stimulation and functional imaging showed connectivity between the ipsilateral hemisphere and the paralyzed arm. There were no significant differences from baseline to month 12 in power, tactile threshold, or two-point discrimination in the hand on the side of the donor graft. RESULTS: The mean increase in Fugl-Meyer score in the paralyzed arm was 17.7 in the surgery group and 2.6 in the control group (difference, 15.1; 95% confidence interval, 12.2 to 17.9; P<0.001). With regard to improvements in spasticity as measured on the Modified Ashworth Scale (an assessment of five joints, each scored from 0 to 5, with higher scores indicating more spasticity), the smallest between-group difference was in the thumb, with 6, 9, and 3 patients in the surgery group having a 2-unit improvement, a 1-unit improvement, or no change, respectively, as compared with 1, 6, and 7 patients in the control group (P=0.02). Transcranial magnetic stimulation and functional imaging showed connectivity between the ipsilateral hemisphere and the paralyzed arm. There were no significant differences from baseline to month 12 in power, tactile threshold, or two-point discrimination in the hand on the side of the donor graft. CONCLUSIONS: In this single-center trial involving patients who had had unilateral arm paralysis due to chronic cerebral injury for more than 5 years, transfer of the C7 nerve from the nonparalyzed side to the side of the arm that was paralyzed was associated with a greater improvement in function and reduction of spasticity than rehabilitation alone over a period of 12 months. Physiological connectivity developed between the ipsilateral cerebral hemisphere and the paralyzed hand. (Funded by the National Natural Science Foundation of China and others; Chinese Clinical Trial Registry number, 13004466 .).

Contralateral C7 Nerve Root Transfer for Function Recovery in Adults: A Meta-analysis.

BACKGROUND: Root avulsion to all 5 roots of the brachial plexus is a common presentation and keeps a major reconstructive challenge. The contralateral C7 (CC7) nerve transfer has been used in treating brachial plexus avulsion injury (BPAI) since 1986. However, the effectiveness of the procedure remains a subject of controversy. The aim of this meta-analysis was to study surgical outcomes regarding motor and sensory recovery after CC7 nerve transfer. METHODS: Chinese or English (i.e., "contralateral c-7", "contralateral c7", "c7 nerve root", and "seventh cervical nerve root") keywords were used for a literature search for articles related to CC7 nerve transfer in several databases (i.e., PubMed, Cochrane, Embase, CNKI, CQVIP, and Wanfang Data). Clinical research articles were screened, and animal studies as well as duplicate publications were excluded. Muscle strength and sensory recovery were considered to be effective only when the scores on the United Kingdom Medical Research Council scale were equal to or higher than M3 and S3, respectively. RESULTS: The overall ipsilateral recipient nerve recovery rates were as follows: the efficiency rate for muscle strength recovery after CC7 nerve transfer was 0.57 (95% confidence interval [CI]: 0.48-0.66) and for sensory recovery was 0.52 (95% CI: 0.46-0.58). When the recipient nerve was the median nerve, the efficiency rate for muscle strength recovery was 0.50 (95% CI: 0.39-0.61) and for sensory was 0.56 (95% CI: 0.50-0.63). When the recipient nerve was the musculocutaneous nerve and the radial nerve, the efficiency rate for muscle strength recovery was 0.74 (95% CI: 0.65-0.82) and 0.50 (95% CI: 0.31-0.70), respectively. CONCLUSIONS: Transfer of CC7 nerves to musculocutaneous nerves leads to the best results. CC7 is a reliable donor nerve, which can be safely used for upper limb function reconstruction, especially for entirely BPAI. When modifying procedures, musculocutaneous nerves and median nerve can be combined as recipient nerves.

End-to-side neurorrhaphy repairs peripheral nerve injury: sensory nerve induces motor nerve regeneration.

End-to-side neurorrhaphy is an option in the treatment of the long segment defects of a nerve. It involves suturing the distal stump of the disconnected nerve (recipient nerve) to the side of the intimate adjacent nerve (donor nerve). However, the motor-sensory specificity after end-to-side neurorrhaphy remains unclear. This study sought to evaluate whether cutaneous sensory nerve regeneration induces motor nerves after end-to-side neurorrhaphy. Thirty rats were randomized into three groups: (1) end-to-side neurorrhaphy using the ulnar nerve (mixed sensory and motor) as the donor nerve and the cutaneous antebrachii medialis nerve as the recipient nerve; (2) the sham group: ulnar nerve and cutaneous antebrachii medialis nerve were just exposed; and (3) the transected nerve group: cutaneous antebrachii medialis nerve was transected and the stumps were turned over and tied. At 5 months, acetylcholinesterase staining results showed that 34% ± 16% of the myelinated axons were stained in the end-to-side group, and none of the myelinated axons were stained in either the sham or transected nerve groups. Retrograde fluorescent tracing of spinal motor neurons and dorsal root ganglion showed the proportion of motor neurons from the cutaneous antebrachii medialis nerve of the end-to-side group was 21% ± 5%. In contrast, no motor neurons from the cutaneous antebrachii medialis nerve of the sham group and transected nerve group were found in the spinal cord segment. These results confirmed that motor neuron regeneration occurred after cutaneous nerve end-to-side neurorrhaphy.

Electrophysiological evidence for pre-attention information processing improvement in patients with central hemiplegic after peripheral nerve rewiring: a pilot study.

Central neurologic injury (CNI) causes dysfunctions not only in limbs but also in cognitive ability. We applied a novel peripheral nerve rewiring (PNR) surgical procedure to restore limb function. Here, we conducted a prospective study to develop estimates for the extent of preattentive processes to cognitive function changes in CNI patients after PNR. Auditory mismatch negativity (MMN) was measured in CNI patients who received the PNR surgery plus conventional rehabilitation treatment. During the 2-year follow-up, the MMN was enhanced with increased amplitude in the PNR plus rehabilitation group compared to the rehabilitation-only group as the experiment progressed, and progressive improvement in behavioural examination tests was also observed. Furthermore, we found a significant correlation between the changes in Fugl-Meyer assessment scale scores and in MMN amplitudes. These results suggested that PNR could affect the efficiency of pre-attention information processing synchronously with the recovery of motor function in the paralyzed arm of the in chronic CNI patients. Such electroencephalographic measures might provide a biological approach with which to distinguish patient subgroups after surgery, and the change in MMN may serve as an objective auxiliary index, indicating the degree of motor recovery and brain cognitive function.

Local and Extensive Neuroplasticity in Carpal Tunnel Syndrome: A Resting-State fMRI Study.

Carpal tunnel syndrome (CTS) is a most common peripheral nerve entrapment neuropathy characterized by sensorimotor deficits in median nerve innervated digits. Block-design task-related functional magnetic resonance imaging (fMRI) studies have been used to investigate CTS-related neuroplasticity in the primary somatosensory cortices. However, considering the persistence of digital paresthesia syndrome caused by median nerve entrapment, spontaneous neuronal activity might provide a better understanding of CTS-related neuroplasticity, which remains unexplored. The present study aimed to investigate both local and extensive spontaneous neuronal activities with resting-state fMRI. A total of 28 bilateral CTS patients and 24 normal controls were recruited, and metrics, including amplitude of low-frequency fluctuation (ALFF) and voxel-wise functional connectivity (FC), were used to explore synaptic activity at different spatial scales. Correlations with clinical measures were further investigated by linear regression. Decreased amplitudes of low-frequency fluctuation were observed in the bilateral primary sensory cortex (SI) and secondary sensory cortex (SII) in CTS patients (AlphaSim corrected P < .05). This was found to be negatively related to the sensory thresholds of corresponding median nerve innervated fingers. In the voxel-wise FC analysis, with predefined seed regions of interest in the bilateral SI and primary motor cortex, we observed decreased interhemispheric and increased intrahemispheric FC. Additionally, both interhemispheric and intrahemispheric FC were found to be significantly correlated with the mean ALFF.

Changes in Expressions of Major Histocompatibility Complex Class I, Paired-Immunoglobulin-Like Receptor B, and Cluster of Differentiation 3ζ in Motor Cortical Representations of the Brachial Plexus After Avulsion in Rats.

OBJECTIVE: Major histocompatibility complex class I (MHCI), paired-immunoglobulin-like receptor B (PirB), and cluster of differentiation 3ζ (CD3ζ) negatively regulate neuronal plasticity in developing and adult brains. The aim of this study was to evaluate expressive changes of these factors in motor cortical representations of the brachial plexus (MCRBP) after total brachial plexus root avulsion (tBPRA). METHODS: A total of 45 rats were randomly and equally divided into 3 groups for evaluating mRNA and protein expression levels of MHCI, PirB, and CD3ζ: 7 days, 3 months, and control. In the 7-day and 3-month groups, expressions were examined at 7 days and 3 months, respectively, after left tBPRA. In the control group, the brachial plexus was uninjured. Three rats from each group were used for examining expressions of MHCI, PirB, and CD3ζ proteins by immunofluorescence labeling, 6 rats for quantification of MHCI, PirB, and CD3ζ mRNAs by real-time quantitative polymerase chain reaction, and the remaining 6 animals for quantification of MHCI, PirB, and CD3ζ proteins by Western blotting. RESULTS: In the original MCRBP, mRNA and protein expression levels of MHCI, PirB, and CD3ζ were down-regulated 7 days postinjury compared with control (P < 0.01). Interestingly, mRNA and protein expression levels of these factors were up-regulated at 3 months compared with 7 days (P < 0.01), excepting PirB protein, whose expression was not increasing (P > 0.05). Recovery of protein expressions were initiated from near the border region of the original MCRBP. CONCLUSIONS: MHCI, PirB, and CD3ζ may participate in motor cortical reorganization after tBPRA.

Outcome of Finger Extension After Nerve Transfer to Repair C7-T1 Brachial Plexus Palsy in Rats: Comparative Study of the Supinator Motor Branch Transfer to the Posterior Interosseous Nerve and the Contralateral C7 Transfer to the Lower Trunk.

BACKGROUND: Functional recovery following supinator motor branch transfer requires further investigation. OBJECTIVE: To compare the outcome of finger extension after supinator motor branch transfer or contralateral C7 (cC7) transfer in C7-T1 brachial plexus palsies in rats. METHODS: In this study, 120 adult rats underwent C7-T1 nerve root avulsion and received different nerve transfer repairs: group A, cC7 nerve transfer to the lower trunk; group B, supinator motor branch nerve transfer to the posterior interosseous nerve (PIN); and group C, no repair. The ethology of the rats, latency and amplitude of the compound muscle action potential from the PIN, muscle mass and muscle fiber cross-sectional area of the extensor digitorum communis and extensor carpi ulnaris, and number of myelinated nerve fibers in the PIN were examined postoperatively. RESULTS: There was no finger extension in group C. We observed finger extension in groups A and B 50.2 ± 5.66 and 13.1 ± 2.08 days postoperatively, respectively. Finger extension restoration in group B was greater than that in group A at 4, 8, and 12 weeks postoperatively ( P < .05). Sixteen weeks after surgery, the recovery rate of the myelinated nerve fibers in group A was marginally higher than that in group B, but the difference was not significant. Of the other measured values, group B showed a greater and significant improvement compared to group A ( P < .05). CONCLUSION: Supinator motor branch transfer allows for faster recovery and is a more effective procedure for restoring finger extension in C7-T1 brachial plexus palsies.

Best time window for the use of calcium-modulating agents to improve functional recovery in injured peripheral nerves-An experiment in rats.

Peripheral nerve injury can have a devastating effect on daily life. Calcium concentrations in nerve fibers drastically increase after nerve injury, and this activates downstream processes leading to neuron death. Our previous studies showed that calcium-modulating agents decrease calcium accumulation, which aids in regeneration of injured peripheral nerves; however, the optimal therapeutic window for this application has not yet been identified. In this study, we show that calcium clearance after nerve injury is positively correlated with functional recovery in rats suffering from a crushed sciatic nerve injury. After the nerve injury, calcium accumulation increased. Peak volume is from 2 to 8 weeks post injury; calcium accumulation then gradually decreased over the following 24-week period. The compound muscle action potential (CMAP) measurement from the extensor digitorum longus muscle recovered to nearly normal levels in 24 weeks. Simultaneously, real-time polymerase chain reaction results showed that upregulation of calcium-ATPase (a membrane protein that transports calcium out of nerve fibers) mRNA peaked at 12 weeks. These results suggest that without intervention, the peak in calcium-ATPase mRNA expression in the injured nerve occurs after the peak in calcium accumulation, and CMAP recovery continues beyond 24 weeks. Immediately using calcium-modulating agents after crushed nerve injury improved functional recovery. These studies suggest that a crucial time frame in which to initiate effective clinical approaches to accelerate calcium clearance and nerve regeneration would be prior to 2 weeks post injury. © 2017 Wiley Periodicals, Inc.

Effect of calcitonin on cultured schwann cells.

INTRODUCTION: After nerve injury, calcium concentrations in intranerve fibers quickly increase. We have shown that functional recovery of injured nerves correlates with calcium absorption. A slight increase in calcium reduces the number of Schwann cells present. Calcitonin therapy greatly improves regeneration by accelerating calcium absorption. We examined the effect of adding calcitonin to higher concentration calcium media on cultured Schwann cells. METHODS: The cells, isolated from intact sciatic nerves, were cultured with normal or higher concentration calcium media with or without calcitonin. Schwann cells were incubated with anti-S-100, goat-anti-mouse, and propidium iodide and then viewed through fluorescent light and phase-contrast microscopy for observation and analysis. RESULTS: The cells in each calcitonin-containing medium showed many Schwann cells, however, the cells in the higher concentration calcium media showed fewer and more defective Schwann cells. CONCLUSION: These results show that calcitonin protects against the harmful effects of excessive calcium encountered in peripheral nerve injury. Muscle Nerve 56: 768-772, 2017.

Multiple nerve and tendon transfers: a new strategy for restoring hand function in a patient with C7-T1 brachial plexus avulsions.

C7-T1 brachial plexus palsies result in a loss of finger motion and hand function. The authors have observed that finger flexion motion can be recovered after a brachialis motor branch transfer. However, finger flexion strength after this procedure merely corresponds to Medical Research Council Grades M2-M3, lowering the grip strength and practical value of the reconstructed hand. Therefore, they used 2 donor nerves and accomplished double nerve transfers for stronger finger flexion. In a patient with a C7-T1 brachial plexus injury, they transferred the pronator teres branch to the anterior interosseous nerve and the brachialis motor branch to the flexor digitorum superficialis branch for reinnervation of full finger flexors. Additionally, the supinator motor branch was transferred for finger extension, and the brachioradialis muscle was used for thumb opposition recovery. Through this new strategy, the patient could successfully accomplish grasping and pinching motions. Moreover, compared with previous cases, the patient in the present case achieved stronger finger flexion and grip strength, suggesting practical improvements to the reconstructed hand.

Automated, highly reproducible, wide-field, light-based cortical mapping method using a commercial stereo microscope and its applications.

We introduce a more flexible optogenetics-based mapping system attached on a stereo microscope, which offers automatic light stimulation to individual regions of interest in the cortex that expresses light-activated channelrhodopsin-2 in vivo. Combining simultaneous recording of electromyography from specific forelimb muscles, we demonstrate that this system offers much better efficiency and precision in mapping distinct domains for controlling limb muscles in the mouse motor cortex. Furthermore, the compact and modular design of the system also yields a simple and flexible implementation to different commercial stereo microscopes, and thus could be widely used among laboratories.