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.

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.

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, β and δ), rapsyn and β-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, β and δ) were significantly lower, whereas β-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.

Designing a 20 mm incision to protect the dorsal branch of the ulnar nerve during arthroscopic repair of triangular fibrocartilage complex injuries: Cadaver study and preliminary clinical results

The ulnar-sided approach for arthroscopic peripheral triangular fibrocartilage complex (TFCC) repair may be associated with injury to the dorsal branch of the ulnar nerve (DBUN). The goal of this study was to develop a small incision to help minimize DBUN injury. Ten cadaveric upper limbs were used to measure the anatomic parameters of the DBUN. Based on these measured anatomical relationships, a 20 mm longitudinal incision with the ulnar styloid process as the midpoint was designed to explore and protect the DBUN. Three additional cadaveric upper limbs were used to test the feasibility of this method. Then this method was applied in 15 patients with TFCC injury (IB type). In 10 cadavers, the DBUN was located volar to the ulnar styloid process. The mean linear distance between the DBUN and the ulnar styloid process was 8.04 mm (range: 7.02-8.82mm) in the transverse-volar direction and 13.78 mm (range: 11.06-16.02mm) in the longitudinal-distal volar direction. In three additional cadavers, the DBUN was successfully explored and retracted with this incision, creating a safer space for passing sutures and tying knots. This modified method was used successfully in 15 patients, and the DBUN was protected during surgery. There were no complications, and most importantly, no injuries to the DBUN at the 6-month follow-up visit. Therefore, we recommend that a 20 mm longitudinal incision with the ulnar styloid process as the midpoint be made prior to passing sutures during the arthroscopic repair of TFCC tears to avoid injuring the various branches of the DBUN.

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

OBJECTIVE

Contralateral 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.

METHODS

This 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.

RESULTS

In 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.

CONCLUSIONS

The 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.

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.

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 .).

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.

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.

Brain functional network abnormality extends beyond the sensorimotor network in brachial plexus injury patients

Brachial plexus injury (BPI) is a type of severe peripheral nerve trauma that leads to central remodeling in the brain, as revealed by functional MRI analysis. However, previously reported remodeling is mostly restricted to sensorimotor areas of the brain. Whether this disturbance in the sensorimotor network leads to larger-scale functional remodeling remains unknown. We sought to explore the higher-level brain functional abnormality pattern of BPI patients from a large-scale network function connectivity dimension in 15 right-handed BPI patients. Resting-state functional MRI data were collected and analyzed using independent component analysis methods. Five components of interest were recognized and compared between patients and healthy subjects. Patients showed significantly altered brain local functional activities in the bilateral fronto-parietal network (FPN), sensorimotor network (SMN), and executive-control network (ECN) compared with healthy subjects. Moreover, functional connectivity between SMN and ECN were significantly less in patients compared with healthy subjects, and connectivity strength between ECN and SMN was negatively correlated with patients' residual function of the affected limb. Functional connectivity between SMN and right FPN were also significantly less than in controls, although connectivity between ECN and default mode network (DMN) was greater than in controls. These data suggested that brain functional disturbance in BPI patients extends beyond the sensorimotor network and cascades serial remodeling in the brain, which significantly correlates with residual hand function of the paralyzed limb. Furthermore, functional remodeling in these higher-level functional networks may lead to cognitive alterations in complex tasks.

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.

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.

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.

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.

Supplementary motor area deactivation impacts the recovery of hand function from severe peripheral nerve injury

Although some patients have successful peripheral nerve regeneration, a poor recovery of hand function often occurs after peripheral nerve injury. It is believed that the capability of brain plasticity is crucial for the recovery of hand function. The supplementary motor area may play a key role in brain remodeling after peripheral nerve injury. In this study, we explored the activation mode of the supplementary motor area during a motor imagery task. We investigated the plasticity of the central nervous system after brachial plexus injury, using the motor imagery task. Results from functional magnetic resonance imaging showed that after brachial plexus injury, the motor imagery task for the affected limbs of the patients triggered no obvious activation of bilateral supplementary motor areas. This result indicates that it is difficult to excite the supplementary motor areas of brachial plexus injury patients during a motor imagery task, thereby impacting brain remodeling. Deactivation of the supplementary motor area is likely to be a serious problem for brachial plexus injury patients in terms of preparing, initiating and executing certain movements, which may be partly responsible for the unsatisfactory clinical recovery of hand function.

Identification of CNS neural circuitry involved in the innervation of C7 spinal nerve: a viral transsynaptic tracing study

OBJECTIVE

Contralateral C7 spinal nerve transfer is a useful operation for the treatment of brachial plexus root avulsion. The recovery of the independent function at the ipsilateral side, however, depends on neural circuitry reorganization in the central nervous system (CNS). This study tried to locate the CNS neuronal elements involved in the innervation of C7 spinal nerve.

METHOD

Pseudorabies virus (PRV, TK/gG(-), 2 microlitre), which expressed green fluorescent protein (GFP), was injected into the left C7 spinal nerve in 20 adult Sprague Dawley rats. After rats survived for 6 h, 12 h, 24 h and 36 h, the C1-C7 segments of the spinal cord and brain were processed using a polyclonal immunohistochemical antibody against PRV.

RESULTS

PRV-labeled neurons were found mainly in gray matter of the C1-C7 segments of the spinal cord and at the following structures of the brain: lateral vestibular nucleus, lateral paragigantocellular nucleus, A5 cells, red nucleus, primary and secondary motor cortexes, primary and secondary somatosensory cortexes. Although located bilaterally, the PRV-labeled neurons existed predominantly in the ipsilateral side of the spinal cord and the contralateral side of the brain at 6-12 h after injection (p.i.). The number of PRV-labeled neurons in the CNS was increasing with rat's survival time and the distribution of these neurons turned bilateral with no obvious dominance to either side at 24 h and 36 h (p.i.).

CONCLUSION

By use of transsynaptic tracing technique with PRV, the anatomically connected set of neurons, which modulates the activity of C7 spinal nerve, is located successfully in the CNS.

Enhancement of Contralesional Motor Control Promotes Locomotor Recovery after Unilateral Brain Lesion

There have been controversies on the contribution of contralesional hemispheric compensation to functional recovery of the upper extremity after a unilateral brain lesion. Some studies have demonstrated that contralesional hemispheric compensation may be an important recovery mechanism. However, in many cases where the hemispheric lesion is large, this form of compensation is relatively limited, potentially due to insufficient connections from the contralesional hemisphere to the paralyzed side. Here, we used a new procedure to increase the effect of contralesional hemispheric compensation by surgically crossing a peripheral nerve at the neck in rats, which may provide a substantial increase in connections between the contralesional hemisphere and the paralyzed limb. This surgical procedure, named cross-neck C7-C7 nerve transfer, involves cutting the C7 nerve on the healthy side and transferring it to the C7 nerve on the paretic side. Intracortical microstimulation, Micro-PET and histological analysis were employed to explore the cortical changes in contralesional hemisphere and to reveal its correlation with behavioral recovery. These results showed that the contralesional hemispheric compensation was markedly strengthened and significantly related to behavioral improvements. The findings also revealed a feasible and effective way to maximize the potential of one hemisphere in controlling both limbs.

Supplementary Motor Cortical Changes Explored by Resting-State Functional Connectivity in Brachial Plexus Injury

BACKGROUND

Brachial plexus injury (BPI) is a serious peripheral nerve injury, and clinical outcomes are generally unsatisfactory. It has been reported that cortical plasticity could influence the restoration of motor function. However, the neurologic mechanism of BPI is unclear, which provides a basis for further investigation. The supplementary motor area (SMA) plays an important role in the regulation of motor function. This study aims to explore SMA-whole brain functional connectivity after deafferentation of the brachial plexus.

METHODS

Study subjects included 16 patients with BPI and 8 healthy volunteers. The seed region was defined by a block-design functional magnetic resonance imaging program that used unilateral imaginary hand grasp motion as a task stimulus. Next, the voxel-wise functional connectivity between the predefined region and the other regions of the brain was calculated.

RESULTS

We discovered decreased voxel-wise functional connectivity between the SMA and multiple brain regions, including precuneus, posterior cingulum cortex, and anterior cingulum cortex, that are closely associated with information integration or motor processing in patients with BPI.

CONCLUSIONS

Patients with BPI showed weakened functional connectivity between hand grasp-related areas and the SMA and multiple regions associated with motor processing or information integration. A clear image of the functional status of the brain after deafferentation was provided. On the basis of this discovery, a relationship between changes in neuroimaging measurements and clinical outcomes can be determined in future studies.

Different cerebral plasticity of intrinsic and extrinsic hand muscles after peripheral neurotization in a patient with brachial plexus injury: A TMS and fMRI study

Contralateral C7 (CC7) neurotization has been an important approach for brachial plexus injury (BPI). Patients can achieve relatively good grasping function driven by the proximal extrinsic hand muscle (flexor digitorum, FD) after CC7 neurotization, whereas the thumb opposition function driven by the distal intrinsic muscle (abductor pollicis brevis, APB) is poor. The present study aimed to investigate the brain reorganization patterns of the recovery processes of intrinsic and extrinsic hand functions after repairing the median nerve by CC7 neurotization. Transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) were used to evaluate the cerebral plasticity in one BPI patient after CC7 neurotization. After the CC7 neurotization, the patient showed improvements in the paralyzed hand. Combination of TMS and fMRI investigations demonstrated different cortical reshaping patterns of APB and FD. It was also found that the activated cortical areas of FD were located in bilateral motor cortices, but the area of APB was only located in ipsilateral motor cortex. The cerebral plasticity procedure appeared to be different in the gross and fine motor function recovery processes. It provided a new perspective into the cerebral plasticity induced by CC7 neurotization.

Distally based perforator sural flaps for foot and ankle reconstruction

Distally based perforator sural flaps from the posterolateral or posteromedial lower leg aspect are initially a neurofasciocutaneous flap that can be transferred reversely to the foot and ankle region with no need to harvest and sacrifice the deep major artery. These flaps are supplied by a perforating artery issued from the deep peroneal artery or the posterior tibial artery, and the chain-linked adipofascial neurovascular axis around the sural/saphenous nerve. It is a versatile and reliable technique for soft-tissue reconstruction of the heel and ankle region with 180-degrees rotation. In this paper, we present its developing history, vascular basis, surgical techniques including flap design and elevation, flap variations in pedicle and component, surgical indications, and illustrative case reports with different perforating vessels as pivot points for foot and ankle coverage.

The Kinematics and Kinetics Analysis of the Lower Extremity in the Landing Phase of a Stop-jump Task

Large number of studies showed that landing with great impact forces may be a risk factor for knee injuries. The purpose of this study was to illustrate the different landing loads to lower extremity of both genders and examine the relationships among selected lower extremity kinematics and kinetics during the landing of a stop-jump task. A total of 35 male and 35 female healthy subjects were recruited in this study. Each subject executed five experiment actions. Lower extremity kinematics and kinetics were synchronously acquired. The comparison of lower extremity kinematics for different genders showed significant difference. The knee and hip maximum flexion angle, peak ground reaction force and peak knee extension moment have significantly decreased during the landing of the stop-jump task among the female subjects. The hip flexion angle at the initial foot contact phase showed significant correlation with peak ground reaction force during landing of the stop-jump task (r=-0.927, p<0.001). The knee flexion angle at the initial foot contact phase had significant correlation with peak ground reaction force and vertical ground reaction forces during landing of the stop-jump task (r=-0.908, p<0.001; r=0.812, P=0.002). A large hip and knee flexion angles at the initial foot contact with the ground did not necessarily reduce the impact force during landing, but active hip and knee flexion motions did. The hip and knee flexion motion of landing was an important technical factor that affects anterior cruciate ligament (ACL) loading during the landing of the stop-jump task.

Origination of the muscular branches of the median nerve: an electrophysiological study

BACKGROUND

In lower brachial plexus injury, finger flexion after brachialis motor branch transfer is relatively weak. We sought to screen potential branches of the median nerve from the upper trunk for strengthening finger flexion in addition to the brachialis motor branch. However, the spinal origin of the muscular branches of the median nerve based on electrophysiological study was unclear.

OBJECTIVE

To determine the spinal origin of the muscular branches of the median nerve.

METHODS

An intraoperative electrophysiological study was carried out in 18 patients who underwent contralateral C7 nerve transfer. After exposure of the brachial plexus nerve roots on the healthy side, the amplitude of the compound muscle action potential of each median nerve-innervated muscle was recorded while the different nerve roots were stimulated.

RESULTS

The pronator teres received fibers from C5, C6, and C7. It had more contribution from C5 and C6 than from C7 (P<.05). The flexor carpi radialis was innervated mainly by C6 and C7. The nerve branches of the palmaris longus and flexor digitorum superficialis stemmed primarily from C7 and the lower trunk, and no significant difference was found between them (P>.05). The flexor digitorum profundus, flexor pollicis longus, pronator quadratus, and abductor pollicis brevis were innervated predominantly by the lower trunk (P<.05).

CONCLUSION

This electrophysiological study indicates that the pronator teres branch might be the most feasible alternative donor nerve to supplement the brachialis motor branch and strengthen finger flexion after lower brachial plexus injury.

Contralateral Peripheral Neurotization for Hemiplegic Upper Extremity After Central Neurologic Injury

BACKGROUND:

Central neurological injury (CNI) is a major contributor to physical disability that affects both adults and children all over the world. The main sequelae of chronic stage CNI are spasticity, paresis of specific muscles, and poor selective motor control. Here, we apply the concept of contralateral peripheral neurotization in spasticity releasing and motor function restoration of the affected upper extremity.

OBJECTIVE:

A clinical investigation was performed to verify the clinical efficacy of contralateral C7 neurotization for rescuing the affected upper extremity after CNI.

METHODS:

In the present study, 6 adult hemiplegia patients received the nerve transfer surgery of contralateral C7 to C7 of the affected side. Another 6 patients with matched pathological and demographic status were assigned to the control group that received rehabilitation only. During the 2-year follow-up, muscle strength of bilateral upper extremities was assessed. The Modified Ashworth Scale and Fugl-Meyer Assessment Scale were used for evaluating spasticity and functional use of the affected upper extremity, respectively.

RESULTS:

Both flexor spasticity release and motor functional improvements were observed in the affected upper extremity in all 6 patients who had surgery. The muscle strength of the extensor muscles and the motor control of the affected upper extremity improved significantly. There was no permanent loss of sensorimotor function of the unaffected upper extremity.

CONCLUSION:

This contralateral C7 neurotization approach may open a door to promote functional recovery of upper extremity paralysis after CNI.

Restoration of hand function in C7-T1 brachial plexus palsies using a staged approach with nerve and tendon transfer

Brachial plexus palsies of C7-T1 result in the complete loss of hand function, including finger and thumb flexion and extension as well as intrinsic muscle function. The task of reanimating such a hand remains challenging, and so far there has been no reliable neurological reconstructive method for restoring hand function. The authors aimed to establish a reliable strategy to reanimate the paralyzed hand. Two patients had sustained C7-T1 complete lesions. In the first stage of the operative procedure, a supinator motor branch to posterior interosseous nerve transfer was performed with brachialis motor branch transfer to the median nerve to restore finger and thumb extension and flexion. In the second stage, the intact brachioradialis muscle was used for abductorplasty to restore thumb opposition. Both patients regained good finger extension and flexion. Thumb opposition was also attained, and overall hand function was satisfactory. The described strategy proved effective and reliable in restoring hand function after C7-T1 brachial plexus palsies.

Pronator Teres Branch Transfer to the Anterior Interosseous Nerve for Treating C8T1 Brachial Plexus Avulsion

BACKGROUND:

The treatment of C8T1 avulsion is challenging for neurosurgeons. Various methods for the restoration of finger flexion are used. However, most of these methods have different disadvantages and cannot restore the full active range of motion of the fingers.

OBJECTIVE:

To determine the feasibility of the pronator teres branch transfer to the anterior interosseous nerve with anatomic study and to use this method in 1 case.

METHODS:

The upper limbs of 15 fresh cadavers were dissected to identify the main trunk of the median nerve, the pronator teres branch, and the anterior interosseous nerve. The mean number and length of the pronator teres branches were recorded. The anterior interosseous nerve was dissected atraumatically to the most proximal level where the fibers of the anterior interosseous nerve did not mingle with the fibers of the main trunk of the median, which was defined as the atraumatic level of the anterior interosseous nerve. A line joining the most protruding point of the medial condyle and lateral condyle of the humerus was used as a measurement landmark. Pronator teres branch transfer to the anterior interosseous nerve was performed in 1 patient with C8T1 avulsion.

RESULTS:

The mean number of the pronator teres branches was 2.37 ± 0.49. The mean length of the pronator teres branches was 9.64 ± 0.71 mm. The mean distance between the point where the pronator teres branches originated and the landmark line was 3.87 ± 0.34 mm. The mean distance between the atraumatic level of the anterior interosseous nerve and the landmark line was −5.46 ± 0.73 mm. Transfer of the pronator teres was used to innervate the anterior interosseous nerve in 1 patient with C8T1 avulsion. When assessed 14 months after the operation, a full active range of motion of the fingers had been restored, and the patient's finger flexor muscles had regained grade 4 power.

CONCLUSION:

The pronator teres can be transferred to the anterior interosseous nerve directly at the elbow level. This operation was performed successfully in 1 patient, who exhibited finger flexion recovery.

A pseudo-planar metasurface for a polarization rotator

New demonstrations of effective interaction between light and artificially electromagnetic interface, or the metasurface, have stimulated intensive research interests on control of light to realize applications in beam steering, optical imaging and light focusing, etc. Here we reported a new type of planar metasurface of which every individual metamolecule is single metallic layer with stereo structure and the metasurface is name as Pseudo-Planar Metasurface (PPM). The metamolecule of the PPM is a chiral structure and therefore derives significant optical activity.

Deactivation of distant pain-related regions induced by 20-day rTMS: a case study of one-week pain relief for long-term intractable deafferentation pain

BACKGROUND

Deafferentation pain secondary to brachial plexus avulsion, spinal cord injury, and other peripheral nerve injuries is often refractory to conventional treatments. Stimulation of the primary motor cortex (M1) has been proven to be an effective treatment for intractable deafferentation pain. The mechanisms underlying the attenuation of deafferentation pain by motor cortex stimulation remain hypothetical.

OBJECTIVES

The purpose of this case report is to: (1) summarize a case in which a patient suffering chronic intractable deafferentation pain for 25 years underwent rTMS treatment over M1, (2) describe the evidence from PET imaging, and (3) reveal a possible relief mechanism with cortical plasticity.

STUDY DESIGN

Case report.

SETTING

University hospital.

RESULTS

This patient had successful pain control with no transient or lasting side effects. The pain relief remained stable for at least one week. At the end of the 20-day procedure, pain relief was obtained according to the Visual Analog Scale (VAS) (-34.6%) and the McGill Pain Questionnaire (MPQ) (-31.6%). In the PET/CT scans, the glucose metabolism was significantly reduced contralaterally to the pain side in the anterior cingulate cortex (ACC), insula, and caudate nucleus. There was no statistically significant difference in any other cortical area.

LIMITATIONS

Single case of a patient with long-term intractable deafferentation pain having a PET study.

CONCLUSION

This study implies that a single session of 20 Hz rTMS over the motor cortex could reduce the pain level in patients suffering from long-term, intractable deafferentation pain. The stimulation of the M1 induces deactivation in the ACC, insula, and caudate nucleus. The changes in these pain-related regions may mirror an adaptive mechanism to pain relief after rTMS treatment.

Arthroscopic distal metaphyseal ulnar shortening osteotomy for ulnar impaction syndrome: a different technique

Ulnar impaction syndrome generally occurs with positive ulnar variance. The solution to the problem is to unload the ulnocarpal joint. Effective surgical options include diaphyseal ulnar shortening osteotomy, open wafer osteotomy, and arthroscopic wafer osteotomy. Recently, Slade and Gillon described an open procedure of ulnar shortening in the osteochondral region of the ulnar head. The procedure minimizes the risk of hemarthrosis and does not require hardware removal, which are problems with other surgical options. This article introduces a new arthroscopic technique of distal metaphyseal ulnar shortening osteotomy for ulnar impaction syndrome. This technique offers the advantages of minimizing surgical injury to the dorsal capsule of the distal radoulnar joint and so protects its stability.

Sensory restoration in cortical level after a contralateral C7 nerve transfer to an injured arm in rats

BACKGROUND

The restoration of sensory and motor function in brachial plexus root avulsion patients is a difficult challenge. The central nervous system plays an important role in sensory recovery after peripheral nerve injury and repair.

OBJECTIVE

To investigate the sensory restoration process after surgery at the cortical level in rodent models with a contralateral C7 nerve transfer.

METHODS

Thirty-five male Sprague-Dawley rats were used in this experiment, and both behavioral tests and somatosensory evoked potentials were used to investigate the sensory function recovery of the injured forepaws and the cortical reorganization in the rats postoperatively.

RESULTS

The results demonstrated a dynamic change in the ipsilateral somatosensory cortex, both in the shape and location, where overlapping sensory cortical representations of the healthy and injured forepaws were observed consistently. Behavioral tests show that the sensation first occurred only in the healthy forepaw and later in both when stimulating the injured one, which suggested a tendency of the sensation function to recover in the injured forepaws of the rats as time progressed.

CONCLUSION

The cortical reorganization occurred only in the ipsilateral hemisphere, which is different from the motor cortex reorganization using the same model as that described in a previous study. This reorganization pattern offers an interpretation of the unique sensory recovery process after the transfer of the C7 nerve to the contralateral median nerve, but also provides the basis for further sensory restoration in clinical practice.

Long-term ongoing cortical remodeling after contralateral C-7 nerve transfer

Object

Contralateral C-7 nerve transfer was developed for the treatment of patients with brachial plexus avulsion injury (BPAI). In the surgical procedure the affected recipient nerve is connected to the ipsilateral motor cortex, and the dramatic peripheral alteration may trigger extensive cortical reorganization. However, little is known about the long-term results after such specific nerve transfers. The purpose of this study was to investigate the long-term cortical adaptive plasticity after BPAI and contralateral C-7 nerve transfer.

Methods

In this study, 9 healthy male volunteers and 5 male patients who suffered from right-sided BPAI and had undergone contralateral C-7-transfer more than 5 years earlier were included. Functional MRI studies were used for the investigation of long-term cerebral plasticity.

Results

The neuroimaging results suggested that the ongoing cortical remodeling process after contralateral C-7 nerve transfer could last for a long period; at least for 5 years. The motor control of the reinnervated limb may finally transfer from the ipsilateral to the contralateral hemisphere exclusively, instead of the bilateral neural network activation.

Conclusions

The authors believe that the cortical remodeling may last for a long period after peripheral rearrangement and that the successful cortical transfer is the foundation of the independent motor recovery.

Outcome after transfer of intercostal nerves to the nerve of triceps long head in 25 adult patients with total brachial plexus root avulsion injury

OBJECT

The intercostal nerves (ICNs) have been used to repair the triceps branch in some organizations in the world, but the reported results differ significantly. The effect of this procedure requires evaluation. Thus, this study aimed to evaluate the outcome of ICN transfer to the nerve of the long head of the triceps muscle and to determine the factors affecting the outcome of this procedure.

METHODS

A retrospective review was conducted in 25 patients with global root avulsion brachial plexus injuries who underwent ICN transfer. The nerves of the long head of the triceps were the recipient nerves in all patients. The ICNs were used in 2 different ways: 2 ICNs were used as donor nerves in 18 patients, and 3 ICNs were used in 7 patients. The mean follow-up period was 5.6 years.

RESULTS

The effective rate of motor recovery in the 25 patients was 56% for the function of the long head of the triceps. There was no significant difference in functional recovery between the patients with 2 or 3 ICN transfers. The outcome of this procedure was not altered if combined with phrenic nerve transfer to the biceps branch. Patients in whom surgery was delayed 6 months or less achieved better results.

CONCLUSIONS

The transfer of ICNs to the nerve of long head of the triceps is an effective procedure for treating global brachial plexus avulsion injuries, even if combined with phrenic nerve transfer to the biceps branch. Two ICNs appear to be sufficient for donation. The earlier the surgery is performed, the better are the results achieved.

Spinal nerve origins of the muscular branches of the radial nerve: an electrophysiological study

BACKGROUND

In injuries of the lower brachial plexus, finger flexion can be restored by nerve or tendon transfer. However, there is no technique that can guarantee good recovery of finger and thumb extension.

OBJECTIVE

To determine the spinal nerve origins of the muscular branches of the radial nerve and identify potential intraplexus donor nerves for neurotization of the posterior interosseous nerve in patients with lower brachial plexus injuries.

METHODS

An intraoperative electrophysiological study was carried out during 16 contralateral C7 nerve transfers. The compound muscle action potential of each muscle innervated by the radial nerve was recorded while the C5-T1 nerves were individually stimulated.

RESULTS

The triceps brachii muscle primarily received root contributions from C7. The C5 and C6 nerve roots displayed greater amplitudes for the brachioradialis and supinator muscles compared with those of the C7, C8, and T1 nerve roots (P < .05). The extensor carpi radialis branch was innervated by C5, C6, and C7, and no significant differences were detected between them (P > .05). The amplitudes obtained for the extensor digitorum communis branch were the largest from C7 and C8, without a significant difference between them (P > .05), whereas the amplitudes of the extensor carpi ulnaris and extensor pollicis longus were largest from the C8 root (P < .05).

CONCLUSION

The supinator muscle branch is likely the best donor nerve for the repair of lower brachial plexus injuries affecting muscles that are innervated by the posterior interosseous nerve.

Clinical research of comprehensive rehabilitation in treating brachial plexus injury patients

BACKGROUND

Brachial plexus injury is one of the difficult medical problems in the world. The aim of this study was to observe the clinical therapeutic effect of comprehensive rehabilitation in treating dysfunction after brachial plexus injury.

METHODS

Forty-three cases of dysfunction after brachial plexus injury were divided into two groups randomly. The treatment group, which totaled 21 patients (including 14 cases of total brachial plexus injury and seven cases of branch brachial plexus injury), was treated with comprehensive rehabilitation including transcutaneous electrical nerve stimulation, mid-frequency electrotherapy, Tuina therapy, and occupational therapy. The control group, which totaled 22 patients (including 16 cases of total brachial plexus injury and six cases of branch brachial plexus injury), was treated with home-based electrical nerve stimulation and occupational therapy. Each course was of 30 days duration and the patients received four courses totally. After four courses, the rehabilitation effect was evaluated according to the brachial plexus function evaluation standard and electromyogram (EMG) assessment.

RESULTS

In the treatment group, there was significant difference in the scores of brachial plexus function pre- and post-treatment (P < 0.01) in both "total" and "branch" injury. The scores of two "total injury" groups had statistical differences (P < 0.01), while the scores of two "branch injury" groups had statistical differences (P < 0.05) after four courses. EMG suggested that the appearance of regeneration potentials of the recipient nerves in the treatment group was earlier than the control group and had significant differences (P < 0.05).

CONCLUSION

Comprehensive rehabilitation was more effective in treating dysfunction after brachial plexus injury than nonintegrated rehabilitation.

Semiquantifying of fascicles of the C7 spinal nerve in the upper and lower subscapular nerves innervating the subscapularis and its clinical inference in Erb's palsy

To elucidate anatomic basis of susceptibility for contracture of the subscapularis muscle in Erb's palsy of the brachial plexus, we semiquantitatively studied the spinal nerve origins of the subscapular nerves innervating the subscapularis, with special reference to the contribution of C7 innervation to the subscapularis. Thirty-three sides of formalin-fixed upper extremities were dissected to obtain the intact brachial plexus. After immersed in 10% acetic acid for 2 weeks, the upper and lower subscapular nerves innervating the whole subscapularis, were dissected retrogradely to verify their spinal nerve origins. The cross-sectional area by C7 innervation and that by the upper trunk innervation was calculated respectively to obtain the constituent percentage of different components in the upper and lower subscapular nerves. In the upper subscapular nerve, fascicles of C7 accounted for 0% (interquartile range, 0-1.1%) of cross-sectional area and those of the upper trunk, 100% (98.9-100%). In the lower subscapular nerve, fascicles of C7 accounted for 40.5% (23.5-47.5%) and those of the upper trunk, 59.5% (52.5-76.5%). In total, 18.6% (13.3-27.3%) of fascicles in the subscapular nerves innervating the subscapularis originated from C7, while 81.4% (72.7-86.7%) of those came from the upper trunk. It is confirmed that innervation of the subscapularis originates from more spinal cord segments than that of infraspinatus and teres minor, and this may be the main reason for which in Erb's palsy, functional recovery of the subscapularis is often faster than that of lateral rotators of the shoulder, resulting in medial rotation contracture of the shoulder.

Contralateral C7 nerve transfer - Our experiences over past 25 years

Contralateral C7 nerve transfer has been used in treating brachial plexus avulsion injury since 1986. During the past two and half decades, much has been achieved, yet more needs to be explored. In this review article, the indications, technical details, outcome and pitfalls of this technique are summarized.

Partial Ipsilateral C7 Transfer to the Upper Trunk for C5-C6 Avulsion of the Brachial Plexus

BACKGROUND:

Ipsilateral whole C7 root transfer has been reported in treating C5-C6 avulsion. To minimize donor deficits, partial ipsilateral C7 (PIC7) transfer was developed.

OBJECTIVE:

To investigate the long-term results of PIC7 transfer to the upper trunk in treating C5-C6 avulsion of the brachial plexus.

METHODS:

We prospectively studied 8 young adults with C5-C6 avulsion. Five patients (group A) who also had spinal accessory nerve (SAN) injury underwent PIC7 transfer to the upper trunk. The other 3 patients (group B) without SAN injury underwent a combination of PIC7 to the upper trunk and the SAN to the suprascapular nerve (SSN). Postsurgical evaluations including donor deficits, functional recovery, and co-contraction of the muscles were performed 1 week later and then at intervals of 3 months.

RESULTS:

After a mean period of 39.2 months, all subjects were found to have gained elbow flexion of 110 to 150° with muscle strength of M4-5. The patients in group B achieved external rotation of 60 to 70° at M3-4, and 2 achieved shoulder abductions approaching 180° at M4. The patients in group A showed no active external rotation and shoulder abduction of 25 to 50° at M2-3. The temporary deficits caused by PIC7 transfer disappeared in all subjects within the first 3 months. Co-contraction of the latissimus dorsi against the deltoid was recorded in group A but not in group B.

CONCLUSION:

PIC7 transfer, when combined with SAN transfer to SSN as a novel approach, is a safe, easy, and efficacious surgical procedure for patients with simple C5-C6 avulsion.

Randomized, double-blind, and placebo-controlled trial of clenbuterol in denervated muscle atrophy

Objectives. β₂-adrenergic agonists, such as clenbuterol, have been shown to promote the hypertrophy of healthy skeletal muscles and to ameliorate muscle wasting in a few pathological conditions in both animals and humans. We intended to investigate the clinical efficacy of clenbuterol on attenuating denervation-induced muscle atrophy. Methods. A double-blind, placebo-controlled, parallel, and randomized trial was employed. 71 patients, suffering from brachial plexus injuries, were given either clenbuterol (60 μg, bid) or placebo for 3 months. Before and at the end of the study, patients were given physical examinations, biopsies of biceps brachii, electromyograms (EMGs), and other laboratory tests. Results. Compared with placebo treatment, clenbuterol significantly mitigated the decreases in cross-sectional areas of type I and II muscle fibers and alleviated the reduction in fibrillation potential amplitudes, without any adverse effects. Conclusions. Clenbuterol safely ameliorated denervated muscle atrophy in this cohort; thus larger clinical studies are encouraged for this or other β₂ agonists on denervation-induced muscle atrophy.

BDNF and GAP43 contribute to dynamic transhemispheric functional reorganization in rat brain after contralateral C7 root transfer following brachial plexus avulsion injuries

It is known that contralateral seventh cervical nerve (C7) root transfer after brachial plexus avulsion injuries (BPAI) causes interhemispheric cortical functional reorganization. However, the potential mechanisms and the role of neurotrophic factors and/or growth-associated protein expression in the process of cerebral reorganization are not well understood. The present study identified the expression of brain-derived neurotrophic factor (BDNF) and growth-associated protein 43 (GAP43) mRNA in primary motor cortex after contralateral C7 root transfer following BPAI. BDNF and GAP43 mRNA levels were significantly increased in brain samples at both 6 and 9 months after contralateral C7 root transfer following BPAI, in comparison with the samples from the rats with BPAI only. These findings indicate that BDNF and GAP43 may play an important role during the dynamic transhemispheric functional reorganization.

Selective Neurotization of the Radial Nerve in the Axilla Using a Full-Length Phrenic Nerve to Treat Complete Brachial Plexus Palsy: An Anatomic Study and Case Report

BACKGROUND:

Current methods for the restoration of wrist and digit extension after a complete brachial plexus injury result in poor outcomes.

OBJECTIVE:

To determine the internal topography of the radial nerve in the axilla and present a method for selective neurotization of the radial nerve using a full-length phrenic nerve.

METHODS:

Internal topographic features of the fascicular groups of the radial nerve were observed at the level of latissimus dorsi insertion in 16 cadavers. Selective neurotization of the medial portion of the antebrachial part of the main trunk of the radial nerve was performed at this level using a full-length phrenic nerve in one patient with complete brachial plexus palsy.

RESULTS:

At the level of latissimus dorsi insertion in the axilla, the antebrachial part of the radial nerve, which innervates the forearm extensors, is located at the superior lateral part of the radial nerve trunk. It can be divided into medial and lateral portions. Transfer of a full-length phrenic nerve was used to selectively reinnervate the medial portion of the antebrachial part of the radial nerve in 1 patient with complete brachial plexus palsy. The patient's antebrachial extensor muscles regained Grade 4 power when assessed 3 years after surgery.

CONCLUSION:

The fibers that innervate the antebrachial extensors are located at the superior lateral part of the radial nerve trunk in the axilla. Selective neurotization of the radial nerve at this level with a phrenic nerve was performed successfully in 1 patient.