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1. Wu KY, Spinner RJ, Shin AY. Traumatic brachial plexus injury: diagnosis and treatment. Curr Opin Neurol. 2022;35(6):708-717. doi:10.1097/WCO.0000000000001124

A comprehensive physical examination aids in localizing (preganglionic or postganglionic) and characterizing the severity of injury (partial or complete). This is crucial to prognostication and determining the optimal reconstructive strategy. A preganglionic injury indicates an avulsion of the rootlets from the spinal cord, precludes the use of that spinal nerve as a donor for nerve grafting, and limits the reconstructive options available. In contrast, a postganglionic injury indicates a lesion distal to the dorsal root ganglion and still affords the possibility of reconstruction with nerve grafts.

The authors institutional preference is to use CT myelography with a multidetector row CT scanner. This allows for submillimeter resolution of the cervical rootlets, which typically measure 1mm in thickness. The classic pathognomic findings of preganglionic BPI are signs of root avulsion and pseudomeningocele formation. Traumatic pseudomeningocele formation results from bulging of the cerebrospinal fluid (CSF)-containing arachnoid membrane through a dural tear. Pseudomeningoceles can also occur in the absence of root avulsions, and therefore, must be correlated with the patient’s clinical examination. Pseudomeningocele formation occurs between 1- and 3-weeks following injury and delaying CT myelography or MRI will provide a higher diagnostic yield. MR neurography allows for greater soft tissue resolution and the ability to image the spinal cord and postganglionic brachial plexus.  Diffusion-weighted MR neurography heavily suppresses background body signals to selectively visualize and highlight tissues, such as nerves, with a long T2 relaxation time. High resolution FIESTA neurography had a 93% accuracy, 84% sensitivity, and 96% specificity in predicting a healthy C5 spinal root amenable for grafting. Additionally, MR provides information on the surrounding soft tissues including cervical spinal cord injury and muscle denervation.

4 figures, 1 table. 48 references with recommended readings.

2. Broekema AEH, Simões de Souza NF, Soer R, et al. Noninferiority of Posterior Cervical Foraminotomy vs Anterior Cervical Discectomy With Fusion for Procedural Success and Reduction in Arm Pain Among Patients With Cervical Radiculopathy at 1 Year. JAMA Neurol. 2023;80(1):40. doi:10.1001/jamaneurol.2022.4208

The Foraminotomy ACDF Cost-Effectiveness Trial (FACET) was designed to compare the clinical- and cost-effectiveness of posterior vs anterior surgery in patients with cervical radiculopathy due to foraminal nerve root compression. Posterior surgery was hypothesized to be noninferior to anterior surgery. The trial includes a follow-up of 2 years. The current study presents the clinical effectiveness results at 1 year of follow-up.

This multicenter investigator-blinded noninferiority randomized clinical trial was conducted from January 2016 to May 2020 with a total follow-up of 2 years. Patients were included from 9 hospitals in the Netherlands. Of 389 adult patients with 1-sided single-level cervical foraminal radiculopathy screened for eligibility, 124 declined to participate or did not meet eligibility criteria. Patients with pure axial neck pain without radicular pain were not eligible. Of 265 patients randomized (132 to posterior and 133 to anterior), 15 were lost to follow-up and 228 were included in the 1-year analysis.

Primary outcomes were proportion of success using Odom criteria and decrease in arm pain using a visual analogue scale from 0 to 100 with a noninferiority margin of 10%. Secondary outcomes were neck pain, disability, quality of life, work status, treatment satisfaction, reoperations, and complications.

Among 265 included patients, the mean (SD) age was 51.2 (8.3) years; 133 patients (50%) were female and 132 (50%) were male. Patients were randomly assigned to posterior (132) or anterior (133) surgery. The proportion of success was 0.88 (86 of 98) in the posterior surgery group and 0.76 (81 of 106) in the anterior surgery group and the between-group difference in arm pain was −2.8 at 1-year follow-up, indicating noninferiority of posterior surgery. Decrease in arm pain had a between-group difference of 3.4, crossing the noninferiority margin with 1.8 points.

These findings suggest noninferiority of posterior surgery compared to anterior surgery and may be used to inform patient counseling and shared decision-making between physicians and patients with 1-sided foraminal radiculopathy.

3 tables, 2 figures, no imaging

3. Mitchell P, Lee SCM, Yoo PE, et al. Assessment of Safety of a Fully Implanted Endovascular Brain-Computer Interface for Severe Paralysis in 4 Patients. JAMA Neurol. Published online January 9, 2023:1-9. doi:10.1001/jamaneurol.2022.4847

Case reports of investigational BCI devices have described control of exoskeletons, prosthetic limbs, and communication technologies and demonstrated the ability to directly decode speech and handwriting from cortical motor activity. Application to wider patient populations is limited, in part by the invasiveness of craniotomy or partial skull removal to implant electrodes in or on the brain. The blood vessels of the brain offer a less invasive route for obtaining access to the motor cortex. Venous stenting has routinely been performed for treating idiopathic intracranial hypertension in the transverse sinus, with a major complication rate of less than 2%. An endovascular device incorporating recording electrodes and implantable in the superior sagittal sinus has recently been developed (Stentrode; Synchron).

The Stentrode With Thought-Controlled Digital Switch (SWITCH) study, a single-center, prospective, first in-human study, evaluated 5 patients with severe bilateral upper-limb paralysis, with a follow-up of 12 months. From a referred sample, 4 patients with amyotrophic lateral sclerosis and 1 with primary lateral sclerosis met inclusion criteria and were enrolled in the study. Surgical procedures and follow-up visits were performed at the Royal Melbourne Hospital, Parkville, Australia. Training sessions were performed at patients’ homes and at a university clinic. The study start date was May 27, 2019, and final follow-up was completed January 9, 2022.

In this prospective, open-label, first in-human study conducted in Australia, an endovascular motor neuroprosthesis BCI implanted in the SSS of 4 patients with severe paralysis was associated with no serious adverse events and no occlusion of target vessels or device migration during the 12-month follow-up period. The BCI maintained a stable signal through- out the study, and all participants successfully controlled a computer with the BCI. Endovascular access to the sensorimotor cortex offers an alternative to BCI technologies, where electrodes are placed in or on the dura by open-brain surgery.

3 figures

4. Hara T, Matsushige T, Yoshiyama M, Hashimoto Y, Kobayashi S, Sakamoto S. Association of circumferential aneurysm wall enhancement with recurrence after coiling of unruptured intracranial aneurysms: a preliminary vessel wall imaging study. J Neurosurg. 2022;138(January):1-7. doi:10.3171/2022.4.jns22421

Recent histopathological studies of unruptured intracranial aneurysms (UIAs) have confirmed that aneurysm wall enhancement (AWE) on MR vessel wall imaging (VWI) is related to wall degeneration with in vivo inflammatory cell infiltration. Therefore, pretreatment aneurysm wall status on VWI may be associated with recurrence after endovascular treatment.

VWI with gadolinium was performed on 67 consecutive saccular unruptured intracranial aneurysms before endovascular treatment between April 2017 and June 2021. The mean (range) follow-up period after treatment was 24.4 months. AWE patterns were classified as circumferential AWE (CAWE), focal AWE (FAWE), and negative AWE (NAWE).

AWE patterns were as follows: 10 CAWE (14.9%), 20 FAWE (29.9%), and 37 NAWE (55.2%). Follow-up MRA detected aneurysm recurrence in 18 of 69 cases (26.1%). Univariate analysis identified maximum diameter (5.8 mm in patients with stable aneurysms vs 7.7 mm in those with unstable aneurysms), aspect ratio, aneurysm location in posterior circulation (4.1% vs 27.8%), volume embolization ratio, and AWE pattern as significant predictive factors of recurrence. Among the 3 AWE patterns, CAWE was significantly more frequent in the unstable group, but no significant differences in stability of the treated aneurysms were observed with the FAWE and NAWE patterns. In multivariate logistic regression analysis, CAWE pattern and volume embolization ratio ≥ 25% remained as significant factors associated with aneurysm stability after coiling.

They conclude that the CAWE pattern, which suggests a specific feature of aneurysm wall degeneration, may negatively affect the durability of coiled aneurysms. Although the long-term stability of coiled aneurysms and the requirement for retreatment currently remain unclear, VWI before coiling provides novel insights into the stability of coiled aneurysms.

3 tables, 3 figures with angio and MR

5. Hasegawa H, Inoue A, Helal A, Kashiwabara K, Meyer FB. Pineal cyst: results of long-term MRI surveillance and analysis of growth and shrinkage rates. J Neurosurg. 2022;138(January):1-7. doi:10.3171/2022.4.jns22276

Pineal cyst (PC) is a common abnormality located adjacent to or within t