Nerve transfer rehabilitation in tetraplegia: Comprehensive assessment and treatment program to improve upper extremity function before and after nerve transfer surgery, a case report

Abstract

Context

A 28-year-old male, sustained a traumatic Spinal Cord Injury (SCI) in January 2015, and was classified as AIS A, neurological level of injury (NLI) C4. As an inpatient at the SCI rehabilitation unit, he underwent multidisciplinary assessment involving SCI specialists, peripheral nerve surgeons, psychologists, occupational and physical therapists. Team consensus determined he was a candidate for nerve transfer surgery to improve upper extremity function. The patient undertook a pre-surgical neurorehabilitation program of 3 months duration. Surgery was performed bilaterally at 11 and 13 months after SCI (right and left arm respectively).

Findings

Upon completion of surgical procedures, the patient underwent an intensive post-surgical rehabilitation program based on established goals, with follow-up every 3 months, up to 24 months after the surgery. Notable improvements were wheelchair propulsion, the ability to relieve pressure, grasp, pinch, and release an object. Standardized measures for SCI individuals (SCIM-III, CUE-Q, LiSAT-9 and UEMS) showed significant improvements.

Clinical Relevance

Nerve transfers in tetraplegia are an underused technique. The benefits of surgery along with an intensive neurorehabilitation program, can improve independence and function in daily living activities for a properly selected group of individuals.

Introduction

Cervical Spinal Cord Injury (SCI) results in a devastating loss of arm and hand function.¹ Individuals with SCI have residual function above, and reduced or no function at and below the neurological level of injury (NLI). In tetraplegia, this functional boundary depends upon the NLI,² and is key determinant of upper extremity function, participation, return to work, independence and quality of life.³

Functional recovery of upper extremities is of the highest priority in tetraplegia,^4–7 even above bowel and bladder function, sexuality, pain and the ability to walk.⁸ Novel surgical and non-surgical treatments have been developed. Among these treatments, nerve transfer surgery is one of the most underutilized, and stands as an attractive option for motor and sensory recovery, as well as pain management, with better outcomes in comparison to tendon transfers.^9–11

Reconstructive surgical procedures in tetraplegia are being performed in many centers worldwide.⁴ Though description of surgical techniques and outcome measures are prominent in literature, there is lack of specific guidelines for postoperative management.⁴ Nerve transfer procedures imply new challenges for rehabilitation, such as promoting nerve regeneration and task-specific training to gradually isolate recipient muscle from donor. Emerging postoperative interventions, guided by principles of motor learning and skill development, are very promising for upper extremity functional improvement in tetraplegia.⁸

In this case report, a detailed description of the proposed pre and post-surgical intervention is presented as well as follow-up assessment using SCI specific functional scales. The subject in this case provided consent to use his health information.

Case presentation

A 28-year-old male sustained a traumatic SCI, ASIA impairment scale (AIS) A, NLI C4, due to C6-C7 fracture-dislocation during a motorcycle accident in January 2015. Reduction and stabilization were performed during the following 48 h. In March 2015, he attended outpatient care at the National Institute of Rehabilitation (INR) in Mexico City. Upon arrival to the SCI outpatient clinic, complications were detected, such as stage III pressure ulcer, malnutrition, and poor clearance of airway secretions. In September 2015, the patient was admitted to the specialized SCI rehabilitation unit (INR) for multidisciplinary assessment and a comprehensive neurological rehabilitation program, with objectives tailored to AIS and NLI.¹²

Preoperative clinical evaluation and rehabilitation

As part of standard management, the subject underwent integrative review by our team, along with application of SCI specific scales. The psychometric properties of tests and measures recommended for the assessment of upper limb and hand function for tetraplegia are summarized by standardized measures across multiple domains of the International Classification of Functioning, Disability and Health (ICF). The assessment tools mentioned below, which are validated for SCI patients reflect these domains: AIS, upper extremity motor score (UEMS), and spinal cord independence measure (SCIM-III) for function, SCIM-III and capabilities of upper extremity questionnaire (CUE-Q) for activity and participation, SCIM-III and life satisfaction questionnaire (LiSAT-9) for environmental factors. AIS has 75–95% validity and 90–98% reliability, UEMS 78–82% validity and 52–81% reliability, SCIM-III 80–97% validity and 72–99% reliability, CUE-Q 73-92% validity and 88–96% reliability, LiSAT-9 52–60% validity and 70–75% reliability. Dynamometry and trunk control were also assessed.

As the subject had no comorbidities, complete range of motion (ROM), no important contractures, no spasticity in upper extremities, and emotional stability according to psychological assessment, he was considered a proper candidate for nerve transfer surgery to improve upper extremities function. An informed consent was given to the patient, and all risks and benefits of surgical procedure were explained.

After patient consent, the specific nerve transfers chosen were tailored to the patient and in accordance with the literature.^1,5,13 Donor nerves were selected from muscles graded 4 or 5 according to the Medical Research Council scale for muscle strength (MRC). The patients’ motor level, which functionally translates weakness for elbow extension and absence of pinch, grasp or release bilaterally, was used to determine the recipient nerves.

Surgical procedure

Surgery was performed bilaterally: 11 and 13 months after SCI for right and left arm respectively. Right-sided procedures consisted of nerve transfer from posterior deltoid branch of axillary nerve to triceps long head branch of radial nerve, long thoracic nerve to posterior interosseous nerve (PIN) through sural nerve graft and brachioradialis branch of radial nerve to median motor branch (Fig. 1). Left-sided procedures comprised: nerve transfer from posterior deltoid branch of axillary nerve to triceps long head branch of radial nerve, brachioradialis branch of radial nerve to PIN, and pronator teres branch of median nerve to anterior interosseous nerve (AIN). The individual participated in a pre-surgical neurorehabilitation program based on well-defined objectives, 3 months prior to intervention. Such as prevention of contractures and maintenance of ROM, as well as strengthening of donor nerve muscles and shoulder girdle.

Figure 1.

Left: Transfer of radial (brachioradialis) to median motor branch; Right: Nerve transfer of long thoracic nerve to Posterior Interosseous nerve (PIN).

Intensive rehabilitation program before and after the surgical procedure (Table 1).

Table 1. A detailed description of the rehabilitation program.^2,4,14,15 .

Phase	Time since surgery	Indications	Precautions
Phase 0 (Before surgery)	3 months before surgery	– Active assisted mobilization to maintain range of motion (ROM), shoulder, elbow, wrist and fingers. – Stretching of the upper extremities (biceps, wrist extensors, finger flexors). – Strengthening of muscles: posterior deltoid, carpal extensors, braquioradialis and pronator teres and muscles of the shoulder girdle. – Postural training to improve trunk control.
Phase 1 (Management of edema and pain)	0–2 weeks (w)	– Cryotherapy for the first 72 h post-surgery. – Promote wound healing and, minimize scarring. – Prevention and detection of pressure areas. – Active movement as tolerated by the patient: shoulder flexion and abduction limited to 90°, un-restricted active movement of the elbow, and passive movement for wrist and fingers.	– Exclusively in the axilla, avoiding the areas above the nerve transfers.
Phase 2 (Initial treatment)	2 w–4 w	– Active-assisted mobilization to improve ROM of shoulder and elbow. Passive mobilization for wrist and fingers (progressively). – Stretching of the upper extremities (biceps, wrist extensors, finger flexors). – Electrical stimulation (preferred stimulation waveform: monophasic triangular) to recipient nerve muscles: triceps brachii, extensor digitorumcommunis and flexor digitorumprofundus. – Motor Re-education is initiated (pairing donor and recipient movement through active donor movement and assisted recipient movement).	– Movement and stretching: 2 times daily. – After surgical staple removal, electrical stimulation once daily (avoid fatigue). *45 min per session.
Phase 3 (Motor re-education)	4 w–12 w or Medical Research Council Manual Muscle Testing scale MRC 1	– Active movement of the shoulder and elbow. – Active-assisted movement for the wrist and fingers. – Stretching of the upper extremities (biceps, wrist extensors, finger flexors). – Electrical stimulation to recipient nerve muscles. – Continued motor re-education. – Initiation of functional activities to maintain and / or increase cortical representation.	– Movement, stretching and motor re-education: 3 times per daily, with electrical stimulation once daily. *45–60 min per session.
Phase 4 (Muscle strengthening)	12 w–24 w or MRC 2	– Active and assisted movement of the joints. – Stretching of the upper extremities (biceps, wrist extensors, finger flexors). – Electrical stimulation (isolating the action of the recipient, once daily). – Muscular re-education (only recipient nerve muscle, twice a day). – Activities promoting grip and pinch.	– Movement and stretching: 3 times daily, with electrical stimulation once daily. *45–60 min per session.
Phase 5 (Functional training)	MRC 3 or >	– Active and assisted movement of the joints. – Stretching of the upper extremities (biceps, wrist extensors, finger flexors). – Electrical stimulation with Russian currents if MRC >3 to recipient nerve muscles. – Strengthening with functional movements and the integration of these movements in activities of daily living.	– Electrical stimulation once daily (avoid muscular fatigue). *45–60 min per session.

*Based on the patients tolerance and avoiding fatigue at all times.

During the first post-surgical year, clinical assessments were carried out monthly, and functional scales were applied every 3 months. After first year, assessment took place every 6 months.

Follow-up and surgical outcome

Improvement of strength was noted bilaterally in triceps brachii, extensor digitorumcommunis (EDC) and flexor digitorumprofundus (FDP) (Fig. 2(a)).

Figure 2.

(a) Medical Research Council (MRC) for left upper extremity (left graph)/MRC for right upper extremity (right graph). (b) Functional assessment. **On 3rd month post-op UEMS are lower in comparison to the baseline assessment, due to loss of wrist extensor strength, which recovered by the 6th month; SCIM-III: Spinal Cord Independence measure; CUE-Q: Capabilities of upper extremity questionnaire; UEMS: Upper extremity motor score; LiSAT-9: Life Satisfaction Questionnaire.

Eight months after initiating multidisciplinary management, the patient presented a change in NLI according to AIS scale from C4 to C5. At 20 months, static balance on lightweight wheelchair improved, although poor dynamic balance remained. Currently, the patient performs some steps of clean intermittent catheterization, but still requires some assistance from his caregivers. He is independent in the use of gadgets such as tablets, phones and has returned to work.

At 24 months post-op, improvement of triceps strength enabled the patient to perform a complete lift off the chair. He has initiated transfers with aid of his caregiver and a transfer board, as well as mobilizing his chair completely and independently. The weakness in right-hand finger extensors (MRC 1) is most likely due to surgical considerations, (use of a graft). Longer distances for re-innervation and use of grafts are associated with less optimal outcomes, but are an inevitable necessity in certain situations. On the other hand, strength in left-sided finger extensors, allow the individual to release grasp. Strength of thumb, index and middle finger flexors bilaterally, allow the patient to grasp, hold a pen, send text messages and assist catheter removal. Strength measure with dynamometry and trunk control test, assessed post-surgery showed no changes.

The main improvements achieved were in wheelchair propulsion, ability to relieve pressure, grasping, pinching, and releasing objects. Independence, quality of life and strength measured with standardized measures such as SCIM-III, CUE-Q, LiSAT-9 and UEMS also showed improvements (Fig. 2(b)).

Discussion

The nerve transfers performed in this patient restored active thumb, index and middle finger flexion bilaterally, along with extension of left-sided fingers. Nerve transfer performed to enhance elbow extension, directly to the triceps, resulted in considerable functional improvement. Bearing in mind that the main feasible spontaneous re-innervation generally occurs within the first 6 months after SCI, and that surgery was performed after this period of time, improvements in muscular performance enabled the patient to overcome his expected goals for: independence, self-care, mobilization and transfers in comparison to other individuals of same AIS and NLI.¹⁶ The patient experienced only a brief period of postoperative immobilization, an important variable to consider in tetraplegia, and intensive neurorehabilitation was initiated immediately after surgery.

The literature agrees that duration of time between the initial injury and re-innervation is of paramount importance in peripheral nerve injury, due to target muscle and Schwann cell atrophy.^17,18 In tetraplegia, target muscles below the NLI and their peripheral neural pathways are intact, for this reason successful re-innervation is potentially feasible when performed later.¹⁷

More research is needed, concerning the ideal time of this intervention. Our patient underwent surgery at 11 and 13 months after SCI respectively for right and left arms; taking into account the expected time for spontaneous re-innervation, it is unlikely the procedure overshadowed spontaneous recovery.^19,20

Performing surgery as early as possible is the current consensus, with 6 months post-injury as a landmark. Earlier surgery is encouraged when time-sensitive lower motor neuron injury is identified by proper EMG evaluation.^17,21

As mentioned previously, description of surgical techniques and outcome measures have had a predominant role in literature. In contrast, thoroughly described post-surgical rehabilitation programs are currently lacking, and the need for specific postoperative treatment guidelines remains. The aim of this case study is to report an assessment and rehabilitation program based on sound scientific principles to obtain better post-surgical outcomes.

Nerve transfers to restore upper limb function in SCI, are still an underutilized treatment option. This is most likely due to factors such as lack of expertise, the patient´s perceptions, fears and beliefs about surgery and recovery, and notably the candidate selection and post-operative rehabilitation process, which are long, time-consuming, and require considerable effort from patient and family.^22,23

Conclusion

Nerve transfers in tetraplegia have become a treatment option with positive results. In this case report, surgery along with an intensive neurorehabilitation program demonstrated improvements in activity performance and participation.

Disclaimer statements

Conflict of interest The authors declare that there is no conflict of interest.