Functional outcomes of different surgical treatments for common peroneal nerve injuries: a retrospective comparative study.

BACKGROUND: This study aims to assess the recovery patterns and factors influencing outcomes in patients with common peroneal nerve (CPN) injury. METHODS: This retrospective study included 45 patients with CPN injuries treated between 2009 and 2019 in Jing'an District Central Hospital. The surgical interventions were categorized into three groups: neurolysis (group A; n = 34 patients), nerve repair (group B; n = 5 patients) and tendon transfer (group C; n = 6 patients). Preoperative and postoperative sensorimotor functions were evaluated using the British Medical Research Council grading system. The outcome of measures included the numeric rating scale, walking ability, numbness and satisfaction. Receiver operating characteristic (ROC) curve analysis was utilized to determine the optimal time interval between injury and surgery for predicting postoperative foot dorsiflexion function, toe dorsiflexion function, and sensory function. RESULTS: Surgical interventions led to improvements in foot dorsiflexion strength in all patient groups, enabling most to regain independent walking ability. Group A (underwent neurolysis) had significant sensory function restoration (P < 0.001), and three patients in Group B (underwent nerve repair) had sensory improvements. ROC analysis revealed that the optimal time interval for achieving M3 foot dorsiflexion recovery was 9.5 months, with an area under the curve (AUC) of 0.871 (95% CI = 0.661-1.000, P = 0.040). For M4 foot dorsiflexion recovery, the optimal cut-off was 5.5 months, with an AUC of 0.785 (95% CI = 0.575-0.995, P = 0.020). When using M3 toe dorsiflexion recovery or S4 sensory function recovery as the gold standard, the optimal cut-off remained at 5.5 months, with AUCs of 0.768 (95% CI = 0.582-0.953, P = 0.025) and 0.853 (95% CI = 0.693-1.000, P = 0.001), respectively. CONCLUSIONS: Our study highlights the importance of early surgical intervention in CPN injury recovery, with optimal outcomes achieved when surgery is performed within 5.5 to 9.5 months post-injury. These findings provide guidance for clinicians in tailoring treatment plans to the specific characteristics and requirements of CPN injury patients.

Cadaveric feasibility study of modified contralateral C7 nerve transfer for targeted functional recovery in hemiplegic upper extremity.

BACKGROUND: Contralateral cervical seventh (cC7) nerve to C7 transfer has been proven effective for treating spastic upper limb. However, for those whose major impairment is not in the C7 area, cC7 nerve transfer to other nerve(s) may achieve a better outcome. The aim of this study was to explore the optimal surgical approach for transferring cC7 to one or two nerves by cadaveric study and to discuss the possible applications for hemiplegic patients. METHODS: Modified cC7 transfer to one (five procedures) or two nonadjacent (three procedures) nerve roots was proposed, and success rates of direct coaptation through two surgical approaches were compared: the superficial surface of longus colli (sLC) and the deep surface of longus colli (dLC) approaches. The length, diameter and distance of relevant nerves were also measured in 25 cadavers. RESULTS: Compared with the sLC approach, the distance of the dLC approach was 1.1 ± 0.3 cm shorter. The success rates for the sLC and dLC approaches were as follows, respectively: cC7-C5 surgery, 94% and reached 98%; cC7-C6 surgery, 54% and 96%; cC7-C7 surgery, 42% and 94%; cC7-C8 surgery, 34% and 94%; cC7-T1 surgery, 24% and 62%; cC7-C5C7 surgery, 74% and 98%; cC7-C6C8 surgery, 54% and 98%. cC7-C7T1 surgery, 42% and 88%. CONCLUSIONS: The dLC approach greatly improved direct coaptation rate for cC7 nerve transfer. The modified cC7 nerve transfer procedures are technically feasible for further application in clinic.

Outcomes and prognostic factors for nerve grafting following high radial nerve injury.

In this study, we examined the prognostic factors affecting outcomes following nerve grafting in high radial nerve injuries. Thirty-three patients with radial nerve injuries at a level distal to the first branch to the triceps and proximal to the posterior interosseous nerve were retrospectively studied. After a follow-up of at least 1 year, 24 patients (73%) obtained M3+ wrist extension, 16 (48%) obtained M3+ finger extension and only ten (30%) obtained M3+ thumb extension. Univariate, multivariate and receiver operating characteristic analyses showed that a delay in the repair of less than 6 months, a defect length of less than 5 cm or when grafted with three or more donor nerve cables achieved better recovery. Number of cables used was related to muscle strength recovery but not time to reinnervation. Nerve grafting for high radial nerve injury achieved relatively good wrist extension but poor thumb extension and is affected by certain prognostic factors. Level of evidence: IV.

Application of CUBE-STIR MRI and high-frequency ultrasound in contralateral cervical 7 nerve transfer surgery.

OBJECTIVE: The objective of the study was to investigate the feasibility of CUBE-SITR MRI and high-frequency ultrasound for the structural imaging of the brachial plexus to exclude neoplastic brachial plexopathy or structural variation and measure the lengths of anterior and posterior divisions of the C7 nerve, providing guidelines for surgeons before contralateral cervical 7 nerve transfer. METHODS: A total of 30 patients with CNS and 20 with brachial plexus injury were enrolled in this retrospective study. All patients underwent brachial plexus CUBE-STIR MRI and high-frequency ultrasound, and the lengths of the anterior and posterior divisions of C7 nerve were measured before surgery. Precise length of anterior and posterior divisions of contralateral C7 nerve was measured during surgery. RESULTS: MRI-measured lengths of anterior and posterior divisions of C7 nerves were positively correlated with that measured during surgery (anterior division, r = 0.94, p < .01; posterior division, r = 0.92, p < .01). High agreement was found between MRI-measured and intra-surgery measured length of anterior and posterior divisions of C7 nerve by BLAD-ALTMAN analysis. Ultrasonography could feasibly image supraclavicular C7 nerve and recognize small variant branches derived from middle trunk of C7 nerve root, which could be dissected intra-operatively and confirmed by electromyography during the procedure of contralateral C7 nerve transfer. CONCLUSION: CUBE-STIR MRI had advantages for the imaging of the brachial plexus and measurement of the length of root-trunk-anterior/posterior divisions of C7 nerve. The clinical role of ultrasonography may be a simple way of evaluating general condition of C7 nerve and provide guidelines for contralateral C7 nerve transfer surgery.

Arthroscopy-assisted partial trapeziectomy combined with ligament reconstruction for thumb carpometacarpal joint osteoarthritis: A different technique.

Background: There is no consensus on the best surgery option for thumb carpometacarpal osteoarthritis (CMC OA). The traditional method has the risk of large trauma, obvious metacarpal subsidence, and decreased stability. The aim of this study is to introduce a different technique to restore the function and stability of the first carpal metacarpal joint with minimal trauma, rapid pain relief, reduced complications, and the clinical outcomes in the long-term follow-up was evaluated and statistically analyzed. Methods: This was a retrospective study of 10 patients with a mean age of 51.8 years. The surgery consisted of removing partial trapezium through arthroscopy, reconstructing the stability with flexor carpi radialis suspension and tendon interposition. The subjective assessment included visual analog scale (VAS) of pain, quick disabilities of the arm, shoulder, and hand (Quick-DASH) score, and patient satisfaction. The range of motion, grip strength, pinch strength, and radiographic assessment, which can reflect stability of the thumb, were objectively evaluated and statistically analyzed. Results: Ten patients were monitored at a mean follow-up of 6.8 years. The mean grip strength improved significantly from 16.64 to 22.57 kg after surgery. Pinch strength improved significantly from 3.72 to 5.71 kg on average. The Kapandji score improved significantly from 5.7 to 8.6 on average. 80% (8/10) of the patients were satisfied with this surgery. On objective indicators, the VAS score decreased significantly from 6.4 to 1.3 on average. The mean Quick-DASH score improved significantly from 6.1 to 28.9. Postoperative x-ray showed slight subsidence and dislocation of the first metacarpal in two patients and did not affect the function by measurement. Conclusion: Arthroscopy-assisted partial trapezium resection combined with ligament reconstruction could be a workable and promising surgical technique in patients with thumb CMC OA. It can offer the advantages of minimizing surgical injury by preserving the first carpal metacarpal joint capsule to protect its stability, with a rapid pain relief, function improvement, and satisfactory results in patients' clinical measurements.

MRI-Based Optimization Design of the Pre-Spinal Route of Contralateral C7 Nerve Transfer for Spastic Arm Paralysis.

Purpose: The prespinal route of contralateral cervical 7 nerve transfer developed by Prof. Wendong Xu helps realize the direct anastomosis of the bilateral cervical 7 nerves. However, 20% of operations still require a nerve graft, which leads to an unfavorable prognosis. This study aims to explore the optimized prespinal route with MRI to further improve the prognosis. Methods: The current study enrolled 30 patients who suffered from central spastic paralysis of an upper limb and who underwent contralateral cervical 7 nerve transfer via Prof. Xu's prespinal route through the anterior edge of the contralateral longus colli. MRI images were used to analyze the route length, vertebral artery exposure, and contralateral cervical 7 nerve included angle. Three prespinal routes were virtually designed and analyzed. The selected optimal route was applied to another 50 patients with central spastic paralysis of an upper limb for contralateral cervical 7 nerve transfer. Results: By the interventions on the 30 patients, the middle and posterior routes were shorter than the anterior route in length, but with no statistical difference between the two routes. Of 30 contralateral vertebral arteries, 26 were located at the posterior medial edge of the longus colli. The average included angles of the anterior, middle, and posterior routes were 108.02 ± 7.89°, 95.51 ± 6.52°, and 72.48 ± 4.65°, respectively. According to these data, the middle route was optimally applied to 50 patients, in whom the rate of nerve transplantation was only 4%, and no serious complications such as vertebral artery or brachial plexus injury occurred. Conclusion: The low rate of nerve transplantation in 50 patients and the absence of any serious complications in these cases suggests that the middle route is the optimal one.

Outcomes of ulnar nerve decompression for double crush syndrome.

BACKGROUND: Double crush syndrome (DCS) of the ulnar nerve, including cubital tunnel syndrome with ulnar tunnel syndrome (UTS), is uncommon. This study compares the postoperative outcomes of patients with isolated ulnar tunnel syndrome versus those with double crush syndrome of the elbow and ulnar tunnel. METHODS: This study enrolled 22 patients: 12 underwent cubital tunnel surgery and ulnar tunnel surgery (double crush group); and 10 underwent only ulnar tunnel decompression (isolated UTS group). Postoperative effect evaluation of patients in both groups after at least 2.6 years (mean, 5.1 years and 5.7 years, respectively). Statistical analysis compared postoperative function, physical examination, and patient-reported satisfaction between groups. RESULTS: In terms of postoperative grip strength, there was no difference between the postoperative states of the two groups (0.88 ± 0.04 versus 0.87 ± 0.05), while there was statistical difference in terms of the increment of the grip strength (p = 0.036); the two-point discrimination of isolated UTS group is better than the double crush group (90% versus 83.3%); double crush patients reported lower satisfaction than the UTS group (90% versus 83.3%). CONCLUSIONS: At a minimum of 2.6 years after the nerve decompression, the patients of isolated UTS group are likely to have superior grip strength increment than patients with a history of double crush surgery, and there is no big difference in the final recovery situation. The sensation and satisfaction of isolated UTS group after nerve release were better compared with patients following double crush surgery.

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.

A novel mouse model of contralateral C7 transfer via the pretracheal route: A feasibility study.

BACKGROUND: Contralateral seventh cervical nerve transfer (contralateral C7 transfer) is a novel treatment for patients with spastic paralysis, including stroke and traumatic brain injury. However, little is known on changes in plasticity that occur in the intact hemisphere after C7 transfer. An appropriate surgical model is required. NEW METHOD: We described in detail the anatomy of the C7 in a mouse model. We designed a pretracheal route by excising the contralateral C6 lamina ventralis, and the largest nerve defect necessary for direct neurorrhaphy was compared with defect lengths in a prespinal route. To test feasibility, we performed in-vivo surgery and assessed nerve regeneration by immunofluorescence, histology, electrophysiology, and behavioral examinations. RESULTS: Two types of branching were found in the anterior and posterior divisions of C7, both of which were significantly larger than the sural nerve. The length of the nerve defect was drastically reduced after contralateral C6 lamina ventralis excision. Direct tension-free neurorrhaphy was achieved in 66.7% of mice. The expression of neurofilament in the distal segment of the regenerated C7 increased. Histological examination revealed remyelination. Behavioral tests and electrophysiology tests showed functional recovery in a traumatic brain injury mouse. COMPARISON WITH EXISTING METHODS: This is the first direct tension-free neurorrhaphy mouse model of contralateral C7 transfer which shortened the time of nerve regeneration; previous models have used nerve grafting. CONCLUSIONS: This paper describes a simple, reproducible, and effective mouse model of contralateral C7 transfer for studying brain plasticity and exploring potential new therapies after unilateral cerebral injury.

C7 transfer in a posterior intradural approach for treating hemiplegic upper-limbs: hypothesis and a cadaver feasibility study.

Objective: Contralateral C7 nerve root transfer surgery has been successfully applied to rescue motor function of a hemiplegic upper extremity in patients with central neurological injury. This surgical technique is challenging, and limited anatomical space makes it difficult to manipulate tissues and may lead to higher complication rates. The authors hypothesis a new surgical route in which cervical nerve roots of both donor and recipient sides are exposed from a posterior intradural approach and neurorrhaphy is performed easily and clearly. The feasibility of this operation is tested in a cadaver model. Methods: A fresh cadaver was placed prone. After a standard midline incision and extensive cervical laminectomy, the dura and arachnoid were widely opened, and the spinal nerve roots of C6, C7, and C8 were exposed bilaterally. Nerve grafting was attempted between pairs of donor and recipient nerve roots on contralateral sides of the spinal cord. After completion of neurorrhaphy, the dura was closed. Results: Precise neurorrhaphy could be performed intradurally between posterior and anterior nerve roots of C7 on both sides. Multiple anastomoses of C7 to various nerve roots on the contralateral side could also be performed within the same surgical field with an interposition nerve graft. Conclusion: The posterior intradural repair idea affords many advantages, the pathway is shorter and more straightforward, which provides more access to multiple nerve roots repair in one surgical field, and is more familiar to many neurosurgeons and spine surgeons. It may potentially be adapted for clinical use.

Contralateral Lumbar to Sacral Nerve Rerouting for Hemiplegic Patients After Stroke: A Clinical Pilot Study.

BACKGROUND: Spasticity and muscle weakness are common severe neurologic sequelae after stroke. Contralateral peripheral neurotization has been applied successfully to promote motor function of the hemiplegic upper extremity in patients with central neurological injury. To our knowledge, we present the first report of contralateral lumbar to sacral nerve transfer for the lower extremities in hemiplegic patients after stroke. CASE DESCRIPTION: Two patients were enrolled in the study. The first patient is a 57-year-old man who experienced permanent muscle weakness in his left leg after a right cerebral infarction. The second patient is a 42-year-old man who had spasticity and hemiplegia in both upper and lower limbs on the right side 32 months after a left cerebral hemorrhage. Both patients underwent contralateral lumbar-to-sacral nerve rerouting to improve lower-limb motor function. Twenty months after surgery, both patients experienced significant improvement in ambulatory status. CONCLUSIONS: Although long-term follow-up and a randomized controlled trial are required, this study demonstrates the safety and possible benefits of contralateral lumbar-to-sacral nerve transfer for hemiplegic patients after stroke. This novel surgical approach could provide a new means for lower-limb motor functional recovery.

Comparative effects of implanted electrodes with differing contact patterns on peripheral nerve regeneration and functional recovery.

Electrical stimulation could enhance nerve regeneration and functional recovery. The objective of this study was to evaluate the regenerative effects of implanted electrodes with different contacts in resected sciatic nerve. Sciatic nerve resection and microsurgical repair models were established and randomly divided into four groups (point contact, 1/4 circle contact; whole-circle contact; no electrodes as control). Electrical stimulation was performed and electrophysiological, morphological and histological exams (of the sciatic nerve and muscle) were conducted at 4 and 10 weeks post-implantation. Point and 1/4 circle contact groups showed significantly higher scores in the sciatic functional index (SFI), increased amplitude of compound muscle action potential (AMP) and motor nerve conduction velocity (MNCV) compared to the control group at both 4 and 10 weeks post-implantation. Point and 1/4 circle contact morphologically promoted sciatic nerve regeneration and reduced muscular atrophy with less mechanical injury to the nerve trunk observed compared with the whole-circle contact group at both 4 and 10 weeks post-implantation. Electrodes with point and 1/4 circle contacts represented an alternatively portable and effective method of electrical stimulation to facilitate injured sciatic nerve regeneration and reduce subsequent muscular atrophy, which might offer a promising approach for treating peripheral nerve injuries.

Nerve fascicle transfer using a part of the C-7 nerve for spinal accessory nerve injury.

OBJECTIVE Spinal accessory nerve (SAN) injury results in a series of shoulder dysfunctions and continuous pain. However, current treatments are limited by the lack of donor nerves as well as by undesirable nerve regeneration. Here, the authors report a modified nerve transfer technique in which they employ a nerve fascicle from the posterior division (PD) of the ipsilateral C-7 nerve to repair SAN injury. The technique, first performed in cadavers, was then undertaken in 2 patients. METHODS Six fresh cadavers (12 sides of the SAN and ipsilateral C-7) were studied to observe the anatomical relationship between the SAN and C-7 nerve. The length from artificial bifurcation of the middle trunk to the point of the posterior cord formation in the PD (namely, donor nerve fascicle) and the linear distance from the cut end of the donor fascicle to both sites of the jugular foramen and medial border of the trapezius muscle (d-SCM and d-Traps, respectively) were measured. Meanwhile, an optimal route for nerve fascicle transfer (NFT) was designed. The authors then performed successful NFT operations in 2 patients, one with an injury at the proximal SAN and another with an injury at the distal SAN. RESULTS The mean lengths of the cadaver donor nerve fascicle, d-SCM, and d-Traps were 4.2, 5.2, and 2.5 cm, respectively. In one patient who underwent proximal SAN excision necessitated by a partial thyroidectomy, early signs of reinnervation were seen on electrophysiological testing at 6 months after surgery, and an impaired left trapezius muscle, which was completely atrophic preoperatively, had visible signs of improvement (from grade M0 to grade M3 strength). In the other patient in whom a distal SAN injury was the result of a neck cyst resection, reinnervation and complex repetitive discharges were seen 1 year after surgery. Additionally, the patient's denervated trapezius muscle was completely resolved (from grade M2 to grade M4 strength), and her shoulder pain had disappeared by the time of final assessment. CONCLUSIONS NFT using a partial C-7 nerve is a feasible and efficacious method to repair an injured SAN, which provides an alternative option for treatment of SAN injury.

Brachialis muscle transfer for reconstructing digital flexion after brachial plexus injury or forearm injury.

Restoration of digital flexion after brachial plexus injury or forearm injury has been a great challenge for hand surgeons. Nerve transfer and forearm donor muscle transfer surgeries are not always feasible. The present study aimed at evaluating the effectiveness of restoring digital flexion by brachialis muscle transfer. Ten lower brachial plexus- or forearm-injured patients were enrolled. After at least 12 months following surgery, the middle-finger-to-palm distance was less than 2.5 cm in six patients. In the other four patients with less satisfactory results, secondary tenolysis surgery was performed and the middle-finger-to-palm distances were reduced to 2.0-4.0 cm. The average grasp strength was 20 ± 4 kg. Elbow flexion was not adversely affected. In conclusion, brachialis muscle transfer is an effective method for reconstructing digital flexion, not only in lower brachial plexus injury, but also in forearm injury patients. LEVEL OF EVIDENCE: IV.

Contralateral peripheral neurotization for a hemiplegic hindlimb after central neurological injury.

OBJECTIVE Contralateral peripheral neurotization surgery has been successfully applied to rescue motor function of the hemiplegic upper extremity in patients with central neurological injury (CNI). It may contribute to strengthened neural pathways between the contralesional cortex and paretic limbs. However, the effect of this surgery in the lower extremities remains unknown. In the present study the authors explored the effectiveness and safety of contralateral peripheral neurotization in treating a hemiplegic lower extremity following CNI in adult rats. METHODS Controlled cortical impact (CCI) was performed on the hindlimb motor cortex of 36 adult Sprague-Dawley rats to create severe unilateral traumatic brain injury models. These CCI rats were randomly divided into 3 groups. At 1 month post-CCI, the experimental group (Group 1, 12 rats) underwent contralateral L-6 to L-6 transfer, 1 control group (Group 2, 12 rats) underwent bilateral L-6 nerve transection, and another control group (Group 3, 12 rats) underwent an L-6 laminectomy without injuring the L-6 nerves. Bilateral L-6 nerve transection rats without CCI (Group 4, 12 rats) and naïve rats (Group 5, 12 rats) were used as 2 additional control groups. Beam and ladder rung walking tests and CatWalk gait analysis were performed in each rat at baseline and at 0.5, 1, 2, 4, 6, 8, and 10 months to detect the skilled walking functions and gait parameters of both hindlimbs. Histological and electromyography studies were used at the final followup to verify establishment of the traumatic brain injury model and regeneration of the L6-L6 neural pathway. RESULTS In behavioral tests, comparable motor injury in the paretic hindlimbs was observed after CCI in Groups 1-3. Group 1 started to show significantly lower slip and error rates in the beam and ladder rung walking tests than Groups 2 and 3 at 6 months post-CCI (p < 0.05). In the CatWalk analysis, Group 1 also showed a higher mean intensity and swing speed after 8 months post-CCI and a longer stride length after 6 months post-CCI than Groups 2 and 3 (p < 0.05). Transection of L-6 resulted in transient skilled walking impairment in the intact hindlimbs in Groups 1 and 2 (compared with Group 3) and in the bilateral hindlimbs in Group 4 (compared with Group 5). All recovered to baseline level within 2 months. Histological study of the rat brains verified comparable injured volumes among Groups 1-3 at final examinations, and electromyography and toluidine blue staining indicated successful regeneration of the L6-L6 neural pathways in Group 1. CONCLUSIONS Contralateral L-6 neurotization could be a promising and safe surgical approach for improving motor recovery of the hemiplegic hindlimb after unilateral CNI in adult rats. Further investigations are needed before extrapolating the present conclusions to humans.

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 .).

Cortical Reorganization in Dual Innervation by Single Peripheral Nerve.

BACKGROUND: Functional recovery after peripheral nerve injury and repair is related with cortical reorganization. However, the mechanism of innervating dual targets by 1 donor nerve is largely unknown. OBJECTIVE: To investigate the cortical reorganization when the phrenic nerve simultaneously innervates the diaphragm and biceps. METHODS: Total brachial plexus (C5-T1) injury rats were repaired by phrenic nerve-musculocutaneous nerve transfer with end-to-side (n = 15) or end-to-end (n = 15) neurorrhaphy. Brachial plexus avulsion (n = 5) and sham surgery (n = 5) rats were included for control. Behavioral observation, electromyography, and histologic studies were used for confirming peripheral nerve reinnervation. Cortical representations of the diaphragm and reinnervated biceps were studied by intracortical microstimulation techniques before and at months 0.5, 3, 5, 7, and 10 after surgery. RESULTS: At month 0.5 after complete brachial plexus injury, the motor representation of the injured forelimb disappeared. The diaphragm representation was preserved in the "end-to-side" group but absent in the "end-to-end" group. Rhythmic contraction of biceps appeared in "end-to-end" and "end-to-side" groups, and the biceps representation reappeared in the original biceps and diaphragm areas at months 3 and 5. At month 10, it was completely located in the original biceps area in the "end-to-end" group. Part of the biceps representation remained in the original diaphragm area in the "end-to-side" group. Destroying the contralateral motor cortex did not eliminate respiration-related contraction of biceps. CONCLUSION: The brain tends to resume biceps representation from the original diaphragm area to the original biceps area following phrenic nerve transfer. The original diaphragm area partly preserves reinnervated biceps representation after end-to-side transfer.

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.

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.