Evaluation of Processed Nerve Allograft in Peripheral Nerve Surgery: A Systematic Review and Critical Appraisal.

Peripheral nerve injuries cause substantial problems when not treated properly. A specific problem is reconstruction of nerve defects, which can be treated in different ways. This study aimed to systematically review whether processed nerve allograft (PNA) is justified in reconstruction of a nerve defect in patients after posttraumatic or iatrogenic peripheral nerve injury and to compare PNA with other established methods. Methods: A systematic review with a focused question, PICO (patient, intervention, comparison, outcome) and constraints, was performed. A structured literature search, including several databases, was done to evaluate the existing evidence for outcomes and postoperative complications related to PNA. The certainty of evidence was classified according to Grading of Recommendations, Assessment, Development and Evaluations. Results: No conclusions, concerning differences in outcome of nerve reconstruction using PNA compared with the use of nerve autograft or conduits, could be drawn. The level of certainty for all evaluated outcomes was very low (⊕◯◯◯). Most published studies lack a control group to patients treated with PNA; being only descriptive, making it difficult to compare PNA with established methods without substantial risk of bias. For studies including a control group, the scientific evidence was of very low certainty, due to a low number of included patients, and large, undefined loss of patients during follow-up, rendering a high risk of bias. Finally, the authors often had financial disclosures. Conclusion: Properly conducted randomized controlled trial studies on the use of PNA in reconstruction of peripheral nerve injuries are needed to establish recommendations in clinical practice.

Normalized activation in the somatosensory cortex 30 years following nerve repair in children: an fMRI study.

The clinical outcome following a peripheral nerve injury in the upper extremity is generally better in young children than in teenagers and in adults, but the mechanism behind this difference is unknown. In 28 patients with a complete median nerve injury sustained at the ages of 1-13 years (n = 13) and 14-20 years (n = 15), the cortical activation during tactile finger stimulation of the injured and healthy hands was monitored at a median time since injury of 28 years using functional magnetic resonance imaging (fMRI) at 3 Tesla. The results from the fMRI were compared with the clinical outcome and electroneurography. The cortical activation pattern following sensory stimulation of the median nerve-innervated fingers was dependent on the patient's age at injury. Those injured at a young age (1-13 years) had an activation pattern similar to that of healthy controls. Furthermore, they showed a clinical outcome significantly superior (P = 0.001) to the outcome in subjects injured at a later age; however, electroneurographical parameters did not differ between the groups. In subjects injured at age 14-20 years, a more extended activation of the contralateral hemisphere was seen in general. Interestingly, these patients also displayed changes in the ipsilateral hemisphere where a reduced inhibition of somatosensory areas was seen. This loss of ipsilateral inhibition correlated to increasing age at injury as well as to poor recovery of sensory functions in the hand. In conclusion, cerebral changes in both brain hemispheres may explain differences in clinical outcome following a median nerve injury in childhood or adolescence.

Subjective outcome related to donor site morbidity after sural nerve graft harvesting: a survey in 41 patients.

BACKGROUND: The sural nerve is the most commonly used nerve for grafting severe nerve defects. Our aim was to evaluate subjective outcome in the lower leg after harvesting the sural nerve for grafting nerve defects. METHODS: Forty-six patients were asked to fill in a questionnaire to describe symptoms from leg or foot, where the sural nerve has been harvested to reconstruct an injured major nerve trunk. The questionnaire, previously used in patients going through a nerve biopsy, consists of questions about loss of sensation, pain, cold intolerance, allodynia and present problems from the foot. The survey also contained questions (visual analogue scales; VAS) about disability from the reconstructed nerve trunk. RESULTS: Forty-one out of 46 patients replied [35 males/6 females; age at reconstruction 23.0 years (10-72); median (min-max), reconstruction done 12 (1.2-39) years ago]. In most patients [37/41 cases (90%)], the sural nerve graft was used to reconstruct an injured nerve trunk in the upper extremity, mainly the median nerve [19/41 (46%)].In 38/41 patients, loss of sensation, to a variable extent, in the skin area innervated by the sural nerve was noted. These problems persisted at follow up, but 19/41 noted that this area of sensory deficit had decreased over time. Few patients had pain and less than 1/3 had cold intolerance. Allodynia was present in half of the patients, but the majority of them considered that they had no or only slight problems from their foot. None of the patients in the study required painkillers. Eighty eight per cent would accept an additional sural nerve graft procedure if another nerve reconstruction procedure is necessary in the future. CONCLUSIONS: Harvesting of the sural nerve for reconstruction nerve injuries results in mild residual symptoms similar to those seen after a nerve biopsy; although nerve biopsy patients are less prone to undergo an additional biopsy.

Consequences and adaptation in daily life - patients' experiences three decades after a nerve injury sustained in adolescence.

BACKGROUND: To explore the patients' experiences during the three decades following repair of a nerve injury in the forearm and its consequences for daily life. Strategies that were used to facilitate adaptation were also investigated. METHODS: Fifteen participants with a complete median and/or ulnar nerve injury repaired in the ages from 13-20 years were interviewed using a semi-structured interview guide. The median follow-up time was 31 years (range 23-40). The participants were asked to describe the past and present symptoms of the injured hand, the consequences of the injury for daily life, personal qualities and support from others. In addition, they were asked to describe strategies used to facilitate adaptation. The interviews were subjected to content analysis. RESULTS: The nerve injury lead to sensory and motor deficits in the injured hand, as well as sensitivity to cold and secondary back problems. Emotional reactions to trauma and symptoms related to post-traumatic stress disorder were described, as well as how they managed to cope with such reactions. There was a noticeable impact on education, leisure, professional or domestic life for some, while others could continue by changing e.g. their performance pattern. The participants' life roles and relations were also affected. Both emotion- and problem-based strategies were used to manage challenges in daily life. CONCLUSIONS: The present qualitative study can help us to provide the patient with honest and realistic information about what to expect after a nerve injury at forearm level, without eliminating hope. Emotional reactions to trauma should be identified and dealt with. In addition, health-care professionals can promote a variety of coping mechanisms to facilitate daily living for the injured patients.

Poor electroneurography but excellent hand function 31 years after nerve repair in childhood.

Children, in contrast to adults, show an excellent clinical recovery after a peripheral nerve injury, which may be explained by better peripheral nerve regeneration and a superior plasticity in the young brain. Our aim was to study the long-term electrophysiological outcome after nerve repair in children and young adults and to compare it with the clinical outcome. Forty-four patients, injured at an age younger than 21 years, were assessed by electrophysiology (amplitude, conduction velocity and distal motor latency) at a median of 31 years after a complete median or ulnar nerve injury at the level of the forearm. Electrophysiological evaluation showed pathology in all parameters and in all patients, irrespective of age at injury. No significant differences were observed in the electrophysiological results between those injured in childhood, that is, before the age of 12 years, and those injured in adolescence, that is, between 12 and 20 years of age. In contrast, the clinical nerve function was significantly better for those injured in childhood (87% of complete recovery, P=0.002) compared with those injured in adolescence. We conclude that the mechanism behind the superior clinical outcome in children is not located at the periphery, but is explained by cerebral plasticity.

Cerebral changes after injury to the median nerve: a long-term follow up.

Injury to the peripheral nerves in the upper extremity results in changes in the nerve, and at multiple sites throughout the central nervous system (CNS). We studied the long-term effects of an injury to the median nerve in the forearm with a focus on changes in the CNS. Four patients with isolated injuries of the median nerve in their 20s were examined a mean of 14 years after the injury. Cortical activation was monitored during tactile stimulation of the fingers of the injured and healthy hand using functional magnetic resonance imaging at 3 Tesla. The neurophysiological state and clinical outcome were also examined. Activation in the primary somatosensory cortex was substantially larger during tactile stimulation of the injured hand than with stimulation of the uninjured hand. We also saw a redistribution of hemispheric dominance. Stimulation of the injured median nerve resulted in a substantially increased dominance of the contralateral hemisphere. However, stimulation of the healthy ulnar nerve resulted in a decreased dominance of the contralateral hemisphere. Neurophysiology showed low sensory amplitudes, velocity, and increased motor latency in the injured nerve. Clinically there were abnormalities predominately in the sensory domain. However, there was an overall improved mean result compared with a five year follow-up in the same subjects. The cortical changes could be the result of cortical reorganisation after a changed afferent signal pattern from the injured nerve. Even though the clinical function improved over time it did not return to normal, and neither did the cortical response.

Compression of the lower trunk of the brachial plexus by a cervical rib in two adolescent girls: case reports and surgical treatment.

Presence of a cervical rib in children is extremely rare, particularly when symptoms of compression of the lower trunk of the brachial plexus occur. We present two cases with such a condition, where two young girls, 11 and 16 years of age were treated by resection of the cervical rib after a supraclavicular exploration of the lower trunk of the brachial plexus. The procedure led to successful results, objectively verified with tests in a work simulator, at one year follow-up.