Use of peripheral nerve transfers in tetraplegia: evaluation of feasibility and morbidity

Abstract

Background: Peripheral nerve transfers are being used to improve upper extremity function in cervical spinal cord injury (SCI) patients. The purpose of this study was to evaluate feasibility and perioperative complications following these procedures.

Methods: Eligible SCI patients with upper extremity dysfunction were assessed and followed for a minimum of 3 months after surgery. Data regarding demographics, medical history, physical examination, electrodiagnostic testing, intraoperative nerve stimulation, recipient nerve histomorphometry, surgical procedure, and complications were collected.

Results: Seven patients had surgery on eight limbs, mean age of 28 ± 9.9 years and mean time from SCI injury of 5.1 ± 5.2 years. All patients had volitional elbow flexion and no volitional hand function. The nerve to the brachialis muscle was used as the expendable donor, and the recipients included the anterior interosseous nerve (AIN) (for volitional prehension), nerve branches to the flexor carpi radialis, and flexor digitorum superficialis. Two patients underwent additional nerve transfers: (1) supinator to extensor carpi ulnaris or (2) deltoid to triceps. No patients had any loss of baseline upper extremity function, seven of eight AIN nerve specimens had preserved micro-architecture, and all intraoperative stimulation of recipient neuromuscular units was successful further supporting feasibility. Four patients had perioperative complications; all resolved or improved (paresthesias).

Conclusion: Nerve transfers can be used to reestablish volitional control of hand function in SCI. This surgery does not downgrade existing function, uses expendable donor nerve, and has no postoperative immobilization, which might make it a more viable option than traditional tendon transfer and other procedures.

Keywords: Nerve transfer; Peripheral nerve; Spinal cord injury; Surgery; Tetraplegia.

Figures

Fig. 1

Illustrative diagram showing the use of the combinations of nerve transfers completed in these patients with cervical spinal cord injury and include brachialis to anterior interosseous nerve transfer to restore volitional control over prehension, nerve transfers to restore elbow extension (posterior head of deltoid to triceps), and improve wrist extension (supinator to extensor carpi ulnaris). Additional brachialis nerve fibers were also coapted to restore wrist flexion (to flexor carpi radialis) or finger flexion (to flexor digitorum superficialis) in some cases (©2012, nervesurgery.wustl.edu, Washington University School of Medicine)

Fig. 2

Representative toluidine blue-stained histologic sections from the recipient anterior interosseus nerve section for patient 2 (a) and patient 4 (b), ×100, scale bar is 100 μm. a shows images from patient 2 who is 12 years post-SCI. Note the high number of mature fibers with intact myelin sheaths and preserved architecture indicating preserved lower motor neurons below the level of the SCI. b by comparison shows reduced fiber density, distorted architecture, and heterogeneity of fibers consistent with known partial lower motor neuron involvement in this patient (who underwent surgery to restore motor function within 8 months of the original SCI)