Cortical Plasticity Following Nerve Transfer in the Upper Extremity

ABSTRACT 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.

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Distal nerve transfers: a biology-based rationale

Neurosurgical FOCUS ◽

10.3171/foc.2009.26.2.e12 ◽

2009 ◽

Vol 26 (2) ◽

pp. E12 ◽

Cited By ~ 54

Author(s):

Justin M. Brown ◽

Manish N. Shah ◽

Susan E. Mackinnon

Keyword(s):

Cortical Plasticity ◽

Surgical Repair ◽

Donor Site ◽

Nerve Transfer ◽

Peripheral Nerve Injuries ◽

Nerve Grafts ◽

Nerve Transfers ◽

Common Strategy ◽

Distal Nerve ◽

And Function

Peripheral nerve injuries can result in devastating numbness and paralysis. Surgical repair strategies have historically focused on restoring the original anatomy with interposition grafts. Distal nerve transfers are becoming a more common strategy in the repair of nerve deficits as these interventions can restore function in months as opposed to more than a year with nerve grafts. The changes that take place over time in the cell body, distal nerve, and target organ after axotomy can compromise the results of traditional graft placement and may at times be better addressed with the use of distal nerve transfers. A carefully devised nerve transfer offers restoration of function with minimal (if any) detectable deficits at the donor site. A new understanding of cortical plasticity along with patient reeducation allow for good return of strength and function after nerve transfer.

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Proof of concept for multiple nerve transfers to a single target muscle

eLife ◽

10.7554/elife.71312 ◽

2021 ◽

Vol 10 ◽

Author(s):

Matthias Luft ◽

Johanna Klepetko ◽

Silvia Muceli ◽

Jaime Ibáñez ◽

Vlad Tereshenko ◽

...

Keyword(s):

Upper Extremity ◽

Nerve Transfer ◽

Entry Point ◽

Transfer Model ◽

Prosthetic Control ◽

Tension Free ◽

Nerve Transfers ◽

Single Target ◽

Motor Entry Point ◽

Long Head

Surgical nerve transfers are used to efficiently treat peripheral nerve injuries, neuromas, phantom limb pain or improve bionic prosthetic control. Commonly, one donor nerve is transferred to one target muscle. However, the transfer of multiple nerves onto a single target muscle may increase the number of muscle signals for myoelectric prosthetic control and facilitate the treatment of multiple neuromas. Currently, no experimental models are available for multiple nerve transfers to a common target muscle in the upper extremity. This study describes a novel experimental model to investigate the neurophysiological effects of peripheral double nerve transfers. For this purpose, we developed a forelimb model to enable tension-free transfer of one or two donor nerves in the upper extremity. Anatomic dissections were performed to design the double nerve transfer model (n=8). In 62 male Sprague-Dawley rats the ulnar nerve of the antebrachium alone (n=30) or together with the anterior interosseus nerve (n=32) was transferred to reinnervate the long head of the biceps brachii. Before neurotization, the motor branch to the biceps’ long head was transected at the motor entry point and resected up to its original branch to prevent auto-reinnervation. In all animals, coaptation of both nerves to the motor entry point could be performed tension-free. Mean duration of the procedure was 49 ± 13 min for the single nerve transfer and 78 ± 20 min for the double nerve transfer. Twelve weeks after surgery, muscle response to neurotomy, behavioral testing, retrograde labeling and structural analyses were performed to assess reinnervation. These analyses indicated that all nerves successfully reinnervated the target muscle. No aberrant reinnervation was observed by the originally innervating nerve. Our observations suggest a minimal burden for the animal with no signs of functional deficit in daily activities or auto-mutilation in both procedures. Furthermore, standard neurophysiological analyses for nerve and muscle regeneration were applicable. This newly developed nerve transfer model allows for the reliable and standardized investigation of neural and functional changes following the transfer of multiple donor nerves to one target muscle.

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Nerve transfers in the upper extremity following cervical spinal cord injury. Part 1: Systematic review of the literature

Journal of Neurosurgery Spine ◽

10.3171/2019.4.spine19173 ◽

2019 ◽

Vol 31 (5) ◽

pp. 629-640 ◽

Cited By ~ 3

Author(s):

Jawad M. Khalifeh ◽

Christopher F. Dibble ◽

Anna Van Voorhis ◽

Michelle Doering ◽

Martin I. Boyer ◽

...

Keyword(s):

Systematic Review ◽

Upper Extremity ◽

Cervical Spinal Cord ◽

Motor Nerve ◽

Nerve Transfer ◽

Elbow Extension ◽

Nerve Transfers ◽

Finger Extension ◽

Cord Injury ◽

Upper Extremity Function

OBJECTIVEPatients with cervical spinal cord injury (SCI)/tetraplegia consistently rank restoring arm and hand function as their top functional priority to improve quality of life. Motor nerve transfers traditionally used to treat peripheral nerve injuries are increasingly being used to treat patients with cervical SCIs. In this study, the authors performed a systematic review summarizing the published literature on nerve transfers to restore upper-extremity function in tetraplegia.METHODSA systematic literature search was conducted using Ovid MEDLINE 1946–, Embase 1947–, Scopus 1960–, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and clinicaltrials.gov to identify relevant literature published through January 2019. The authors included studies that provided original patient-level data and extracted information on clinical characteristics, operative details, and strength outcomes after nerve transfer procedures. Critical review and synthesis of the articles were performed.RESULTSTwenty-two unique studies, reporting on 158 nerve transfers in 118 upper limbs of 92 patients (87 males, 94.6%) were included in the systematic review. The mean duration from SCI to nerve transfer surgery was 18.7 months (range 4 months–13 years) and mean postoperative follow-up duration was 19.5 months (range 1 month–4 years). The main goals of reinnervation were the restoration of thumb and finger flexion, elbow extension, and wrist and finger extension. Significant heterogeneity in transfer strategy and postoperative outcomes were noted among the reports. All but one case report demonstrated recovery of at least Medical Research Council grade 3/5 strength in recipient muscle groups; however, there was greater variation in the results of larger case series. The best, most consistent outcomes were demonstrated for restoration of wrist/finger extension and elbow extension.CONCLUSIONSMotor nerve transfers are a promising treatment option to restore upper-extremity function after SCI. Flexor reinnervation strategies show variable treatment effect sizes; however, extensor reinnervation may provide more consistent, meaningful recovery. Despite numerous published case reports describing good patient outcomes with nerve transfers, there remains a paucity in the literature regarding optimal timing and long-term clinical outcomes with these procedures.

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Improving hand function after spinal cord injury

Journal of Hand Surgery (European Volume) ◽

10.1177/17531934211027460 ◽

2021 ◽

pp. 175319342110274

Author(s):

Jan Fridén ◽

James House ◽

Michael Keith ◽

Silvia Schibli ◽

Natasha van Zyl

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Upper Extremity ◽

Muscle Function ◽

Spinal Cord Injuries ◽

Hand Function ◽

Nerve Transfer ◽

Cord Injury ◽

Upper Extremity Function ◽

Improve Planning

Nerve transfer surgery has expanded reconstructive options for restoring upper extremity function following spinal cord injury. By adding new motor donors to the pool already available through tendon transfers, the effectiveness of treatment should improve. Planning which procedures and in which order to perform, along with their details must be delineated. To meet these demands, refined diagnostics are needed, along with awareness of the remaining challenges to restore intrinsic muscle function and to address spasticity and its consequences. This article summaries recent advances in surgical reanimation of upper extremity motor control, together with an overview of the development of neuro-prosthetic and neuromodulation techniques to modify recovery or substitute for functional losses after spinal cord injuries.

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