Stem cell therapy for traumatic brachial plexus injury.

Stem cell therapy is rapidly evolving, with preclinical studies showing various stem cell types successfully promoting peripheral nerve regeneration. Despite the lack of clinical studies demonstrating efficacy and safety, the number of commercial entities marketing and promoting this treatment direct to patients is also increasing. We describe three adult traumatic brachial plexus injury (BPI) patients who had stem cell therapies prior to consultation in a multidisciplinary brachial plexus clinic. No functional improvement was noted at long-term follow-up despite claims reported by the commercial entities. Considerations and implications of stem cell application in BPI patients are reviewed.

The Value of Systematic Reviews in Estimating the Cost and Barriers to Translation in Tissue Engineering.

Little quantitative data exist concerning barriers that impede translation from bench to bedside. We systematically reviewed synthetic or biosynthetic polymer nerve scaffolds for peripheral nerve repair to study a defined research area that is beyond the discovery phase and has potential for clinical application. Using electronic and manual search methods, we identified published English language articles, where scaffolds were tested in preclinical animal models. A systematic review of these 416 reports estimated all costs related to the use of animals, surgery, and evaluation methods. The research studied 17 different nerves in eight animal species, with use of 65 evaluation methods at an estimated cost of $61,264,910 for the preclinical studies. A total of 127 surveys were sent to authors, of whom 12 could not be accessed electronically and 45 (39%) responded. Major causes for failure to translate included lack of a commercial partner, insufficient financial resources, a research program not involved in translation, and lack of expertise in regulatory affairs. This review emphasizes the urgent need for standardization of preclinical models and the need to establish better collaboration between laboratory investigators, clinicians, and the companies involved in commercialization. It identifies important areas for education of future investigators in the process of translation from discovery to improved health such as those funded by the National Institutes of Health Clinical and Translational Science Awards.

A systematic review of animal models used to study nerve regeneration in tissue-engineered scaffolds.

Research on biomaterial nerve scaffolds has been carried out for 50 years. Only three materials (collagen, polycaprolactone and polyglycollic acid) have progressed to clinical use. Pre-clinical animal models are critical for testing nerve scaffolds prior to implementation in clinical practice. We have conducted a systematic review of 416 reports in which animal models were used for evaluation of nerve regeneration into synthetic conduits. A valid animal model of nerve regeneration requires it to reproduce the specific processes that take place in regeneration after human peripheral nerve injury. No distinct animal species meets all the requirements for an ideal animal model. Certain models are well suited for understanding regenerative neurobiology while others are better for pre-clinical evaluation of efficacy. The review identified that more than 70 synthetic materials were tested in eight species using 17 different nerves. Nerve gaps ranged from 1 to 90 mm. More than 20 types of assessment methodology were used with no standardization of methods between any of the publications. The review emphasizes the urgent need for standardization or rationalization of animal models and evaluation methods for studying nerve repair.

Neurosurgical treatment of craniopharyngioma in adults and children: early and long-term results in a large case series.

OBJECT: Craniopharyngioma accounts for 2%-5% of all primary intracranial neoplasms. The optimal management of craniopharyngioma remains controversial. The authors evaluated the early results of surgery and the longterm risk of tumor recurrence in a large series of patients undergoing resection of craniopharyngiomas. METHODS: Between 1990 and 2008, 112 consecutive patients (57 male and 55 female patients with a mean [± SEM] age of 33.3 ± 1.8 years) underwent resection of craniopharyngiomas at the authors' hospital. Recurrence or growth of residual tumor tissue during follow-up was assessed using MR imaging. RESULTS: There were 3 perioperative deaths (2.7%). Severe adverse events were more frequent in patients who underwent operations via the transcranial route (37%) than the transsphenoidal approach (5.6%; p < 0.001). Magnetic resonance imaging showed radical resection of the tumor in 78 (71.6%) of the remaining 109 patients. Previous surgery and maximum tumor diameter were associated with persistence of disease after surgery. Craniopharyngioma recurred in 26 (24.5%) of 106 patients. Presence of residual tumor on the first postoperative MR imaging, male sex, and no postoperative radiation therapy were associated with a risk of tumor recurrence. Quality-of-life data were assessed in the 91 patients who attended the authors' institution for follow-up visits. Among them, 8.8% patients were partially or completely dependent on others for daily living activities before surgery. This percentage increased to 14.3% at the last follow-up visit. The 5- and 10-year overall survival rates were 94.4% (95% CI 90.0%-98.8%) and 90.3% (95% CI 83.4%-97.3%), respectively. CONCLUSIONS: Complete surgical removal of craniopharyngioma can be achieved with reasonable safety in more than 70% of patients. Recurrence of craniopharyngioma may occur even after apparent radical excision. Prompt management of residual or recurring disease by radiotherapy, repeat surgery, or a combination of both is usually successful in controlling further tumor growth.

Infraclavicular brachial plexopathy secondary to coracoid osteoid osteoma.

Coracoid osteoid osteomas are rare. This case report presents two patients with coracoid osteoid osteomas who developed neurologic sequelae of the infraclavicular brachial plexus (namely, musculocutaneous neuropathy in one patient with an anterior lesion, and suprascapular neuropathy in the other patient with a more posterior lesion). The neuropathy was due to soft tissue edema, which surrounded the bony lesion and was apparent on MRI. Surgical resection of the bony lesion in both cases produced excellent outcomes at long-term follow-up.

Peroneal and tibial intraneural ganglia: correlation between intraepineurial compartments observed on magnetic resonance images and the potential importance of these compartments.

OBJECT: Previously the authors demonstrated that peroneal and tibial intraneural ganglia arising from the superior tibiofibular joint may occasionally extend proximally within the epineurium to reach the sciatic nerve. The dynamic nature of these cysts, dependent on intraarticular pressures, may give rise to differing clinical and imaging presentations that have remained unexplained until now. To identify the pathogenesis of these unusual cysts and to correlate their atypical magnetic resonance (MR) imaging appearance, the authors retrospectively reviewed their own experience as well as the published literature on these types of intraneural ganglia. METHODS: A careful review of MR images obtained in 22 patients with intraneural ganglia located about the knee region (18 peroneal and four tibial intraneural ganglia) allowed the authors to substantiate three different patterns: outer (epifascicular) epineurial (20 cases); inner (interfascicular) epineurial (one case); and combined outer and inner epineurial (one case). In these cases serial MR images allowed the investigators to track the movement of the cyst within the same layer of the epineurium. All lesions had connections to the superior tibiofibular joint. Nine patients were identified as having lesions with sciatic nerve extension. Seven patients harboring an outer epineurial cyst (six in whom the cyst involved the peroneal nerve and one in whom it involved the tibial nerve) had signs of sciatic nerve cross-over, with the cyst seen in the sciatic nerve and/or other terminal branches. In only two of these cases had the cyst previously been recognized to have sciatic nerve involvement. In contrast, in one case an inner epineurial cyst involving the tibial nerve ascended within the tibial division of the sciatic nerve and did not cross over. A single patient had a combination of both outer and inner epineurial cysts; these were easily distinguished by their distinctive imaging patterns. CONCLUSIONS: This anatomical compartmentalization of intraneural cysts can be used to explain varied clinical and imaging patterns of cleavage planes for cyst formation and propagation. Compartmentalization elucidates the mechanism for cases of outer epineurial cysts in which there are primary ascent, sciatic cross-over, and descent of the lesion down terminal branches; correlates these cysts' atypical MR imaging features; and contrasts a different pattern of inner epineurial cysts in which ascent and descent occur without cross-over. The authors present data demonstrating that the dynamic phases of these intraneural ganglia frequently involve the sciatic nerve. Their imaging features are subtle and serve to explain the underrecognition and underreporting of the longitudinal extension of these cysts. Importantly, cysts extending to the sciatic nerve are still derived from the superior tibiofibular joint. Combined with the authors' previous experimental data, the current observations help the reader understand intraneural ganglia with a different, deeper degree of anatomical detail.