Posterior fossa microcystic meningioma mimicking an arachnoid cyst.

Microcystic meningioma is an uncommon subtype of World Health Organization grade 1 meningiomas often associated with a shorter progression-free survival. Diagnosis through imaging alone can often be challenging due to atypical characteristics, especially when found in unexpected locations. Here, we present a 55-year-old woman who was diagnosed, based on imaging, with a posterior fossa arachnoid cyst 5 years prior after complaints of headaches and gait imbalance. After surgical resection of the "arachnoid cyst," the diagnosis of microcystic meningioma was made. This case report emphasizes the clinical importance and challenges associated with diagnosing microcystic meningiomas.

A Modified Technique for Interventional MRI-Guided Deep Brain Stimulation Using the ClearPoint System.

BACKGROUND: Deep brain stimulation (DBS) is increasingly performed using imaging-based techniques, which are rapidly evolving to minimize invasiveness and use limited resources efficiently. OBJECTIVE: To describe a modified surgical technique for interventional MRI-guided stereotactic procedures using ClearPoint. METHODS: A total of 160 consecutive DBS cases for Parkinson disease (48%), essential tremor (44%), dual essential tremor/Parkinson disease (3%), and dystonia (5%) were studied. Technique modifications included (1) preplanning the target/trajectory, (2) adoption of a smaller incision and new stereotactic frame, (3) changing the sequence of surgical steps, aiming to final target PRIOR to drilling, (4) reducing burr hole size, (5) minimizing dural opening, and (6) anchoring leads with a bio cement/plate combination in lieu of commercial devices. Demographic data, radial error, number of passes, and case time were prospectively collected while complications and clinical outcomes were retrospectively assessed. RESULTS: One hundred and forty seven DBS patients had 262 total leads placed. Average radial error was 0.41 mm bilaterally. Seventy nine leads had error <0.2 mm; 6 leads had error >1 mm. Pin-to-stylet insertion time, pin-to-frame removal time, and pin-to-room departure time were 2 hours 1 minute, 2 hours 48 minutes, and 3 hours 16 minutes, respectively, and were significantly shorter than those obtained with the original ClearPoint technique for our first 150 DBS cases ( P < .0001). Complications included infection with hardware removal (2.5%) and superficial hemorrhage without permanent neurological sequelae (1.9%). CONCLUSION: The modified ClearPoint technique maintains accuracy while reducing invasiveness and MRI time. This workflow can be expanded to other applications, including laser interstitial thermal therapy and gene delivery.

Investigating the efficacy of allograft cellular bone matrix for spinal fusion: a systematic review of the literature.

OBJECTIVE: The use of allograft cellular bone matrices (ACBMs) in spinal fusion has expanded rapidly over the last decade. Despite little objective data on its effectiveness, ACBM use has replaced the use of traditional autograft techniques, namely iliac crest bone graft (ICBG), in many centers. METHODS: In accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, a systematic review was conducted of the PubMed, Cochrane Library, Scopus, and Web of Science databases of English-language articles over the time period from January 2001 to December 2020 to objectively assess the effectiveness of ACBMs, with an emphasis on the level of industry involvement in the current body of literature. RESULTS: Limited animal studies (n = 5) demonstrate the efficacy of ACBMs in spinal fusion, with either equivalent or increased rates of fusion compared to autograft. Clinical human studies utilizing ACBMs as bone graft expanders or bone graft substitutes (n = 5 for the cervical spine and n = 8 for the lumbar spine) demonstrate the safety of ACBMs in spinal fusion, but fail to provide conclusive level I, II, or III evidence for its efficacy. Additionally, human studies are plagued with several limiting factors, such as small sample size, lack of prospective design, lack of randomization, absence of standardized assessment of fusion, and presence of industry support/relevant conflict of interest. CONCLUSIONS: There exist very few objective, unbiased human clinical studies demonstrating ACBM effectiveness or superiority in spinal fusion. Impartial, well-designed prospective studies are needed to offer evidence-based best practices to patients in this domain.

The Medical Review Panel in Louisiana Neurosurgery and Beyond.

For the past several decades, medical malpractice claims in the state of Louisiana have been screened by a pretrial medical review panel (MRP). Composed of 3 physicians and 1 attorney, these panels are a method of filtering nonmeritorious lawsuits while expediting creditable claims. Currently, 14 jurisdictions in the United States require medical liability/malpractice cases be heard by an MRP or screening panel prior to trial. In this article, we review the MRP process in Louisiana and compare it to those in other states. Data are presented for the past 10 yr of malpractice claims in Louisiana with an emphasis on the neurosurgery specialty. Finally, the benefits and challenges of pretrial screening panels are discussed.

Potential of Human Nucleus Pulposus-Like Cells Derived From Umbilical Cord to Treat Degenerative Disc Disease.

BACKGROUND: Degenerative disc disease (DDD) is a common spinal disorder that manifests with neck and lower back pain caused by the degeneration of intervertebral discs (IVDs). Currently, there is no treatment to cure this debilitating ailment. OBJECTIVE: To investigate the potential of nucleus pulposus (NP)-like cells (NPCs) derived from human umbilical cord mesenchymal stem cells (MSCs) to restore degenerated IVDs using a rabbit DDD model. METHODS: NPCs differentiated from MSCs were characterized using quantitative real-time reverse transcription polymerase chain reaction and immunocytochemical analysis. MSCs and NPCs were labeled with fluorescent dye, PKH26, and transplanted into degenerated IVDs of a rabbit model of DDD (n = 9 each). Magnetic resonance imaging of the IVDs was performed before and after IVD degeneration, and following cell transplantation. IVDs were extracted 8 wk post-transplantation and analyzed by various biochemical, immunohistological, and molecular techniques. RESULTS: NPC derivatives of MSCs expressed known NP-specific genes, SOX9, ACAN, COL2, FOXF1, and KRT19. Transplanted cells survived, dispersed, and integrated into the degenerated IVDs. IVDs augmented with NPCs showed significant improvement in the histology, cellularity, sulfated glycosaminoglycan and water contents of the NP. In addition, expression of human genes, SOX9, ACAN, COL2, FOXF1, KRT19, PAX6, CA12, and COMP, as well as proteins, SOX9, ACAN, COL2, and FOXF1, suggest NP biosynthesis due to transplantation of NPCs. Based on these results, a molecular mechanism for NP regeneration was proposed. CONCLUSION: The findings of this study demonstrating feasibility and efficacy of NPCs to regenerate NP should spur interest for clinical studies to treat DDD using cell therapy.

Human umbilical cord derivatives regenerate intervertebral disc.

Intervertebral disc (IVD) degeneration is characterized by the loss of nucleus pulposus (NP), which is a common cause for lower back pain. Although, currently, there is no cure for the degenerative disc disease, stem cell therapy is increasingly being considered for its treatment. In this study, we investigated the feasibility and efficacy of human umbilical cord mesenchymal stem cells (MSCs) and chondroprogenitor cells (CPCs) derived from those cells to regenerate damaged IVD in a rabbit model. Transplanted cells survived, engrafted and dispersed into NP in situ. Significant improvement in the histology, cellularity, extracellular matrix proteins, and water and glycosaminoglycan contents in IVD recipients of CPCs was observed compared to MSCs. In addition, IVDs receiving CPCs exhibited higher expression of NP-specific human markers, SOX9, aggrecan, collagen 2, FOXF1 and KRT19. The novelty of the study is that in vitro differentiated CPCs derived from umbilical cord MSCs, demonstrated far greater capacity to regenerate damaged IVDs, which provides basis and impetus for stem cell based clinical studies to treat degenerative disc disease. Copyright © 2016 John Wiley & Sons, Ltd.