Jack, Megan M.

OBJECTIVE Common peroneal (fibular) neuropathy is the most common mononeuropathy of the lower extremity. Despite this, there are surprisingly few studies on the topic, and a knowledge gap remains in the literature. As one attempts to address this knowledge gap, a core outcome set (COS) is needed to guide the planning phases of future studies to allow synthesis and comparability of these studies. The objective of this study was to develop the COS–common peroneal neuropathy (CoPe) using a modified Delphi approach. METHODS A 5-stage approach was used to develop the COS-CoPe: 1) stage 1, consortium development; 2) stage 2, a literature review to identify potential outcome measures; 3) stage 3, a Delphi survey to develop consensus on outcomes for inclusion; 4) stage 4, a Delphi survey to develop definitions; and 5) stage 5, a consensus meeting to finalize COS and definitions. The study followed the COS–STAndards for Development (COS-STAD) recommendations. RESULTS The Core Outcomes in Nerve Surgery (COINS) Consortium comprised 23 participants, all neurological surgeons, representing 13 countries. The final COS-CoPe consisted of 31 data points/outcomes covering domains of demographics, diagnostics, patient-reported outcomes, motor/sensory outcomes, and complications. Appropriate instruments, methods of testing, and definitions were set. The consensus minimum duration of follow-up was 12 months. The consensus optimal time points for assessment were preoperatively and 3, 6, 12, and 24 months postoperatively. CONCLUSIONS The COINS Consortium developed a consensus COS and provided definitions, methods of implementation, and time points for assessment. The COS-CoPe should serve as a minimum set of data that should be collected in all future neurosurgical studies on common peroneal neuropathy. Incorporation of this COS should help improve consistency in reporting, data synthesis, and comparability, and should minimize outcome reporting bias.

OBJECTIVE When considering traumatic brachial plexus and upper extremity nerve injuries, iatrogenic nerve injuries, and nontraumatic nerve injuries, brachial plexus and upper extremity nerve injuries are commonly encountered in clinical practice. Despite this, data synthesis and comparison of available studies are difficult. This is at least in part due to the lack of standardization in reporting and a lack of a core outcome set (COS). Thus, there is a need for a COS for adult brachial plexus and upper extremity nerve injuries (COS-BPUE). The objective of this study was to develop a COS-BPUE using a modified Delphi approach. METHODS A 5-stage approach was used to develop the COS-BPUE: 1) consortium development, 2) literature review to identify potential outcome measures, 3) Delphi survey to develop consensus on outcomes for inclusion, 4) Delphi survey to develop definitions, and 5) consensus meeting to finalize the COS and definitions. The study followed the Core Outcome Set-STAndards for Development (COS-STAD) recommendations. RESULTS The Core Outcomes in Nerve Surgery (COINS) Consortium comprised 23 participants, all neurological surgeons, representing 13 countries. The final COS-BPUE consisted of 36 data points/outcomes covering demographic, diagnostic, patient-reported outcome, motor/sensory outcome, and complication domains. Appropriate instruments, methods of testing, and definitions were set. The consensus minimum duration of follow-up was 24 months, with the consensus optimal time points for assessment being preoperatively and 3, 6, 12, and 24 months postoperatively. CONCLUSIONS The COINS Consortium developed a consensus COS and provided definitions, methods of implementation, and time points for assessment. The COS-BPUE should serve as a minimum set of data that should be collected in all future neurosurgical studies on adult brachial plexus and upper extremity nerve injuries. Incorporation of this COS should help improve consistency in reporting, data synthesis, and comparability, and should minimize outcome reporting bias.

OBJECTIVE Ulnar neuropathy at the elbow (UNE) is common, affecting 1%–6% of the population. Despite this, there remains a lack of consensus regarding optimal treatment. This is primarily due to the difficulty one encounters when trying to assess the literature. Outcomes are inconsistently reported, which makes comparing studies or developing meta-analyses difficult or even impossible. Thus, there is a need for a core outcome set (COS) for UNE (COS-UNE) to help address this problem. The objective of this study was to utilize a modified Delphi method to develop COS-UNE. METHODS A 5-stage approach was utilized to develop COS-UNE: stage 1, consortium development; 2, literature review to identify potential outcome measures; 3, Delphi survey to develop consensus on outcomes for inclusion; 4, Delphi survey to develop definitions; and 5, consensus meeting to finalize the COS and definitions. The study followed the Core Outcome Set-STAndards for Development (COS-STAD) recommendations. RESULTS The Core Outcomes in Nerve Surgery (COINS) Consortium comprised 21 participants, all neurological surgeons representing 11 countries. The final COS-UNE consisted of 22 data points/outcomes covering the domains of demographic characteristics, diagnostics, patient-reported outcomes, motor/sensory outcomes, and complications. Appropriate instruments, methods of testing, and definitions were set. The consensus minimum duration of follow-up was 6 months, with the consensus optimal timepoints for assessment identified as preoperatively and 3, 6, and 12 months postoperatively. CONCLUSIONS The authors identified consensus data points/outcomes and also provided definitions and specific scales to be utilized to help ensure that clinicians are consistent in their reporting across studies on UNE. This COS should serve as a minimum set of data to be collected in all future neurosurgical studies on UNE. The authors hope that clinicians evaluating ulnar neuropathy will incorporate this COS into routine practice and that future studies will consider this COS in the design phase.

OBJECTIVE The objective of this study was to determine if patients with nerve sheath tumors affecting the C5 spinal nerve are at greater risk for postoperative weakness than those with similar tumors affecting other spinal nerves contributing to the brachial plexus. METHODS A retrospective chart review (1998–2020)identified patients with pathologically confirmed schwannomas or neurofibromas from the C5 to T1 nerves. Patients with plexiform nerve sheath tumors, tumors involving more than 1 nerve, and malignant peripheral nerve sheath tumors were excluded. Collected variables included basic demographics, tumor dimensions, its location relative to the dura, involved nerve level, surgical approach, extent of resection, presenting symptoms, postoperative neurological deficits, and recurrence rate. RESULTS Forty-six patients (23 men, 23 women) were identified for inclusion in the study with an average age of 47 ± 17 years, BMI of 28 ± 5 kg/m2, and follow-up of 32 ± 45 months. Thirty-nine patients (85%) had schwannomas and 7 (15%) had neurofibromas. Tumors involved the C5 (n = 12), C6 (n = 11), C7 (n = 14), C8 (n = 6), and T1 (n = 3) nerves. Multivariable logistic regression analysis with an area under the curve of 0.85 demonstrated C5 tumor level as an independent predictor of new postoperative weakness (odds ratio 7.4, p = 0.028). Of those patients with new postoperative weakness, 75% improved and 50% experienced complete resolution of their motor deficits. CONCLUSIONS Patients with C5 nerve sheath tumor resections are at higher odds of new postoperative weakness. This may be due to the predominant single innervation of shoulder muscle targets in contrast to other upper extremity muscles that receive input from 2 or more spinal nerves. These findings are important for clinical decision-making and preoperative patient counseling.

BACKGROUND The advancement of high-resolution imaging and increased clinical experience have led to an increased understanding of the formation and treatment of intraneural ganglion cysts. Nearly all intraneural ganglion cysts in the common peroneal nerve have been reported to arise from a joint connection to the superior tibiofibular joint. The authors have identified four cases of intraneural ganglion cysts arising from the knee joint itself; however, none of these reported cases were well described, documented, or illustrated with high-resolution imaging. OBSERVATIONS Here the authors present the case of an intraneural ganglion cyst arising from the knee joint and causing intermittent weakness and pain. The articular branch to the knee joint was clearly demonstrated on high-resolution magnetic resonance imaging and confirmed at surgical exploration. The patient was treated with articular branch ligation and has had complete resolution of his symptoms without recurrence of the cyst on follow-up imaging. LESSONS This case adds to the mounting evidence that intraneural cyst pathology is dependent on a connection to a synovial joint as stated in the unifying theory of intraneural cyst development.