Schwalb, Jason M.

Since its US Food and Drug Administration approval in 2016, magnetic resonance–guided focused ultrasound (MRgFUS) thalamotomy has grown into one of the procedures of choice among patients with essential tremor (ET). Approved applications for the procedure have expanded over time from unilateral thalamotomy to treat ET and Parkinson disease tremor to bilateral staged thalamotomy for ET. As the procedure expands to healthcare environments beyond large academic centers, guidance is required to ensure that the responsible clinicians are appropriately trained to undertake this operative procedure. Although multidisciplinary movement disorder teams are important for the optimal management of patients, MRgFUS lesions are inherently surgical interventions. Neurosurgeons are trained to evaluate these patients, consider surgical alternatives and conduct these operations, particularly after completing a fellowship in the subspecialty of stereotactic and functional neurosurgery. At present, all high-level evidence regarding the safety and efficacy of MRgFUS lesions to treat movement disorders derives from procedures performed by neurosurgeons, so those results may not be generalizable to other physicians. Based on these considerations and potential liability issues, the American Society for Stereotactic and Functional Neurosurgery, which acts as the joint section representing the field of stereotactic and functional neurosurgery on behalf of the Congress of Neurological Surgeons and the American Association of Neurological Surgeons, puts forth this position statement that only neurosurgeons appropriately trained to conduct functional neurosurgery procedures should conduct MRgFUS surgical lesions.

OBJECTIVE Magnetic resonance–guided focused ultrasound (MRgFUS) thalamotomy has become a popular tool in the neurosurgical armamentarium for managing tremor in patients with essential tremor (ET) and Parkinson’s disease (PD). METHODS Given the recent exponential growth in the use of this technology, the American Society for Stereotactic and Functional Neurosurgery, which acts as the joint section representing the field of stereotactic and functional neurosurgery on behalf of the Congress of Neurological Surgeons and the American Association of Neurological Surgeons, provides an update on treatment indications and the efficacy and safety of MRgFUS for the treatment of tremor. RESULTS In ET, the efficacy of MRgFUS thalamotomy is supported by several open-label and 1 prospective, double-blind, sham-controlled randomized clinical trial (RCT) that showed a 47% improvement in hand tremor in the short term. Follow-up studies demonstrated that the benefits of MRgFUS for ET are sustained in the long term. Studies investigating the effects of bilateral staged MRgFUS thalamotomy in patients with ET have shown that tremor improvement on the second side was as significant as that observed after the first procedure. The efficacy of MRgFUS thalamotomy for PD tremor is supported by a systematic meta-analysis that consisted predominantly of smaller, nonrandomized studies; 1 RCT; and 1 prospective cohort study. Despite a significant short-term improvement in PD tremor, the long-term effects of this therapy remain unknown. Common early adverse effects of MRgFUS thalamotomy include gait disturbance and paresthesias. These, however, tend to subside over time. Other reported side effects are dysarthria, ataxia, taste disturbance, motor deficits, and speech difficulty. CONCLUSIONS MRgFUS thalamotomy is a safe, effective, and durable intervention for refractory ET in appropriately selected patients. The procedure appears to be safe and effective for PD tremor, although the long-term durability of the technique remains a concern. Early experience with bilateral staged lesions for ET suggests the procedure to be safe and effective.

Spinal cord stimulation (SCS) is a surgical treatment for chronic neuropathic pain refractory to medical management. An SCS system comprised one or more leads implanted in the epidural space, typically connected to an implantable pulse generator. This review discusses the history, indications, surgical technique, technological advances, and future directions of SCS.

Significant knowledge gaps exist in the perioperative pain management of patients with a history of chronic pain, substance use disorder, and/or opioid tolerance as highlighted in the US Health and Human Services Pain Management Best Practices Inter-Agency Task Force 2019 report. The report emphasized the challenges of caring for these populations and the need for multidisciplinary care and a comprehensive approach. Such care requires stakeholder alignment across multiple specialties and care settings. With the intention of codifying this alignment into a reliable and efficient processes, a consortium of 15 professional healthcare societies was convened in a year-long modified Delphi consensus process and summit. This process produced seven guiding principles for the perioperative care of patients with chronic pain, substance use disorder, and/or preoperative opioid tolerance. These principles provide a framework and direction for future improvement in the optimization and care of ‘complex’ patients as they undergo surgical procedures.

PurposeAlthough rare overall, marginal zone B-cell lymphoma (MZBCL) is the most common primary low-grade CNS lymphoma reported in the literature. The aim of this study is to elucidate the biology and genetic features of this unusual tumor.Patients and MethodsFifteen CNS MZBCLs were studied clinically, pathologically, and genetically, including fluorescent in situ hybridization analyses with commercially available MALT1 and IgH break-apart and centromere 3, 7, 12, and 18 probes.ResultsCNS MZBCLs preferentially affect middle-aged women (female-to-male ratio, 4:1), with 93% presenting as dural-based masses mimicking meningioma. Ten patients with 1 to 7.6 years of follow-up after diagnosis showed no evidence of disease after radiation and/or chemotherapy. Like MZBCLs outside of the CNS, they consisted of CD20+, CD3−small B lymphocytes with varying degrees of plasmacytic differentiation and predominantly κ light-chain restriction (78%). Lymphoid follicles with follicular colonization were seen in three patients and deposition of amyloid was noted in samples from two patients, one of which was tumefactive. Neither Bcl-6 protein nor Epstein-Barr virus–encoded RNA was expressed. Trisomy 3 was detected in six of 12 patients, with no rearrangements of MALT1 or IgH and no trisomies of 7, 12, or 18 detected.ConclusionOur data suggest that intracranial MZBCL is an indolent primary CNS lymphoma that typically presents as a meningioma-like dural-based mass. Trisomy 3, but not MALT1 or IgH translocation, is a common genetic abnormality that may contribute to the pathogenesis of this CNS lymphoma.