Cortical Plasticity After Surgical Tendon Transfer in Tetraplegics

Adult traumatic brachial plexus injuries: advances and current updates

Nerve grafting, tendon transfer and joint fusion are routinely used to improve the upper limb function in patients with brachial plexus palsies. Newer techniques have been developed that provide additional options for reconstruction. Nerve transfer is a tool for restoring upper limb function in total root avulsions where nerve grafting is not possible. In partial brachial plexus injuries, nerve transfers can greatly improve shoulder, elbow, wrist and hand function. Intraoperative electrical stimulation can be used to diagnose precisely which nerve is injured and to choose which nerve fascicles should be transferred. Finally, measuring the postoperative outcome can improve the evaluation of our techniques. The aim of this article was to present the current techniques used to treat patients with brachial plexus injury.

The Surgical Restoration of Arm and Hand Function in Tetraplegic Patients

BACKGROUND

There are approximately 140 000 people in Germany with spinal cord injury, with approximately 2400 new patients each year. Cervical spinal cord injuries cause, to varying degrees, weakness and impairment of everyday activities of the limbs (tetraparesis, tetraplegia).

METHODS

This review is based on relevant publications retrieved by a selective search of the literature.

RESULTS

From among 330 initially screened publications, 40 were included and analyzed. Muscle and tendon transfers, tenodeses, and joint stabilizations yielded reliable functional improvement of the upper limb. Tendon transfers improved the strength of elbow extension from M0 to an average of M3.3 (BMRC) and grip strength to approximately 2 kg. In the long term, 17-20% of strength is lost after active tendon transfers and slightly more after passive ones. Nerve transfers improved strength to M3 or M4 in over 80% of cases, with the best results overall in patients under 25 years of age who underwent early surgery (within 6 months of the accident). Combined procedures in a single operation have been found to be advantageous compared to the traditional multistep approach. Nerve transfers from intact fascicles at segmental levels above that of the spinal cord lesion have been found to be a valuable addition to the established varieties of muscle and tendon transfer. The reported long-term patient satisfaction is generally high.

CONCLUSION

Modern techniques of hand surgery can help suitably selected tetraparetic and tetraplegic patients regain the use of their upper limbs. Competent interdisciplinary counseling about these surgical options should be offered as early as possible to all affected persons as an integral part of their treatment plan.

Rethinking the Body in the Brain after Spinal Cord Injury

Spinal cord injuries (SCI) are disruptive neurological events that severly affect the body leading to the interruption of sensorimotor and autonomic pathways. Recent research highlighted SCI-related alterations extend beyond than the expected network, involving most of the central nervous system and goes far beyond primary sensorimotor cortices. The present perspective offers an alternative, useful way to interpret conflicting findings by focusing on the deafferented and deefferented body as the central object of interest. After an introduction to the main processes involved in reorganization according to SCI, we will focus separately on the body regions of the head, upper limbs, and lower limbs in complete, incomplete, and deafferent SCI participants. On one hand, the imprinting of the body’s spatial organization is entrenched in the brain such that its representation likely lasts for the entire lifetime of patients, independent of the severity of the SCI. However, neural activity is extremely adaptable, even over short time scales, and is modulated by changing conditions or different compensative strategies. Therefore, a better understanding of both aspects is an invaluable clinical resource for rehabilitation and the successful use of modern robotic technologies.

Regional estimates of cortical thickness in brain areas involved in control of surgically restored limb movement in patients with tetraplegia

Context/Objective: Spinal cord injury (SCI) causes atrophy of brain regions linked to motor function. We aimed to estimate cortical thickness in brain regions that control surgically restored limb movement in individuals with tetraplegia. Design: Cross-sectional study. Setting: Sahlgrenska University hospital, Gothenburg, Sweden. Participants: Six individuals with tetraplegia who had undergone surgical restoration of grip function by surgical transfer of one elbow flexor (brachioradialis), to the paralyzed thumb flexor (flexor pollicis longus). All subjects were males, with a SCI at the C6 or C7 level, and a mean age of 40 years (range = 31-48). The average number of years elapsed since the SCI was 13 (range = 6-26). Outcome measures: We used structural magnetic resonance imaging (MRI) to estimate the thickness of selected motor cortices and compared these measurements to those of six matched control subjects. The pinch grip control area was defined in a previous functional MRI study. Results: Compared to controls, the cortical thickness in the functionally defined pinch grip control area was not significantly reduced (P = 0.591), and thickness showed a non-significant but positive correlation with years since surgery in the individuals with tetraplegia. In contrast, the anatomically defined primary motor cortex as a whole exhibited substantial atrophy (P = 0.013), with a weak negative correlation with years since surgery. Conclusion: Individuals with tetraplegia do not seem to have reduced cortical thickness in brain regions involved in control of surgically restored limb movement. However, the studied sample is very small and further studies with larger samples are required to establish these findings.

Comparison of the Wide-Awake Approach and Conventional Approach in Extensor Indicis Proprius-to-Extensor Pollicis Longus Tendon Transfer for Chronic Extensor Pollicis Longus Rupture

BACKGROUND

The wide-awake approach enables surgeons to perform optimal tensioning of a transferred tendon intraoperatively. The authors hypothesized that the extensor indicis proprius-to-extensor pollicis longus tendon transfer using the wide-awake approach would yield better results than conventional surgery.

METHODS

A retrospective analysis was performed of the prospectively collected data of 29 consecutive patients who underwent extensor indicis proprius-to-extensor pollicis longus tendon transfer. Patients were treated with the wide-awake approach (group A, n = 11) and conventional surgery under general anesthesia (group B, n = 18). The groups were compared retrospectively for thumb interphalangeal and metacarpophalangeal joint motion, grip and pinch strength, specific extensor indicis proprius-to-extensor pollicis longus evaluation method (SEEM), and Disabilities of the Arm, Shoulder and Hand questionnaire score at 6 weeks and 2, 4, 6, and 12 months postoperatively.

RESULTS

Group A showed significantly better interphalangeal joint flexion and total arc of motion at 6 weeks and 2, 4, and 6 months, and significantly better metacarpophalangeal joint flexion and total arc of motion at all time points. Interphalangeal and metacarpophalangeal joint extension showed no difference at all time points. Group A showed significantly better specific extensor indicis proprius-to-extensor pollicis longus evaluation method scores at 2 and 4 months, and Disabilities of the Arm, Shoulder and Hand questionnaire scores at 4, 6, and 12 months. Grip and pinch strength showed no difference at all time points. The complication rate and duration until return to work were not different between groups.

CONCLUSION

Compared with the conventional approach, the wide-awake approach showed significantly better results in the thumb's range of motion and functional outcomes, especially in the early postoperative periods.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.