Open Surgical Treatment of Middle Cerebral Artery Aneurysms: A Single-Center Series in the Endovascular Era

OBJECTIVE

We review the outcomes of open surgical treatment of middle cerebral artery aneurysms (MCAAs) at a single center, focusing on aneurysm obliteration rates and functional outcomes at the most recent follow-up. These findings can be used for future comparisons of surgical outcomes with MCAAs.

METHODS

We retrospectively reviewed cases from a prospectively maintained database of patients receiving open surgical treatment for ruptured or unruptured MCAAs between July 2014 and December 2022. We utilized patients' modified Rankin Scale (mRS) score and Glasgow Outcome Scale score as functional outcome measures. Means, standard deviations, medians, and interquartile ranges were calculated, and a student's t test or its nonparametric equivalent was used to compare subgroups.

RESULTS

One hundred fifty patients (114 women, 76%; mean age 55.0 ± 14.7 years) with a total of 156 MCAAs comprised 152 cases; 85 (56%) ruptured and 71 (46%) unruptured. Bypass was performed in 34 cases (22.4%); 18 ruptured (51.4%) and 16 unruptured (48.6%). Intraoperative rupture occurred in 5 (5%) ruptured and 1 (2%) unruptured cases. Onwe hundred forty-five patients (95.4%) had aneurysm obliteration with initial surgery, with 98.4% of patients having complete occlusion at 40.2± 65.5 weeks of follow-up. Intrahospital mortality occurred in 7 (6.9%) ruptured versus 1 (2.0%) unruptured case. Fifty-two (51.5%) of the ruptured compared to 43 (86%) unruptured patients were discharged home, with the remaining patients requiring inpatient rehabilitation or long-term hospitalization. The ruptured group had a mean hospital stay of 18.4 ± 10.5 days versus. 5.7 ± 6.0 days for unruptured. Length of stay, discharge mRS/ Glasgow Outcome Scale, and mRS at 4-6 weeks favored unruptured cases (P < 0.0001-0.0336). Mean change in mRS from presentation to last follow-up favored ruptured cases (-0.7 ± 1.2 vs. -0.04 ± 1.2, P = 0.0215).

CONCLUSIONS

Open surgery remains a safe and definitive treatment option for MCAAs in the endovascular era.

Three-Vessel Anastomosis for Direct Multiterritory Cerebral Revascularization: Case Series

BACKGROUND AND OBJECTIVE

Cerebral revascularization of multiple territories traditionally requires multiple constructs, serial anastomoses, or a combination of direct and indirect approaches. A novel 3-vessel anastomosis technique allows for direct, simultaneous multiterritory cerebral revascularization using a single interposition graft. We herein present our experience with this approach.

METHODS

Retrospective review of perioperative data and outcomes for patients undergoing multiterritory cerebral revascularization using a 3-vessel anastomosis from 2019 to 2023.

RESULTS

Five patients met inclusion criteria (median age 53 years [range 12-73]). Three patients with complex middle cerebral artery aneurysms (1 ruptured) were treated with proximal ligation or partial/complete clip trapping and multiterritory external carotid artery-M2-M2 revascularization using a saphenous vein interposition graft. Two patients with moyamoya disease, prior strokes, and predominately bilateral anterior cerebral artery hypoperfusion were treated with proximal superficial temporal artery-A3-A3 revascularization using a radial artery or radial artery fascial flow-through free flap graft. No patients experienced significant surgery-related ischemia. Bypass patency was 100%. One patient had new strokes from vasospasm after subarachnoid hemorrhage. One patient required a revision surgery for subdural hematoma evacuation and radial artery fascial flow-through free flap debridement, without affecting bypass patency or neurologic outcome. On hospital discharge, median Glasgow Outcome Scale and modified Rankin Scale scores were 4 (range 3-5) and 2 (range 0-5), respectively. On follow-up, 1 patient died from medical complications of their presenting stroke; Glasgow Outcome Scale and modified Rankin Scale scores were otherwise stable or improved.

CONCLUSION

The 3-vessel anastomosis technique can be considered for simultaneous revascularization of multiple intracranial territories.

Pathological Bergmann glia alterations and disrupted calcium dynamics in ataxic Canavan disease mice

Canavan disease (CD) is a recessively inherited pediatric leukodystrophy resulting from inactivating mutations to the oligodendroglial enzyme aspartoacylase (ASPA). ASPA is responsible for hydrolyzing the amino acid derivative N-acetyl-L-aspartate (NAA), and without it, brain NAA concentrations increase by 50% or more. Infants and children with CD present with progressive cognitive and motor delays, cytotoxic edema, astroglial vacuolation, and prominent spongiform brain degeneration. ASPA-deficient CD mice (Aspanur7/nur7 ) present similarly with elevated NAA, widespread astroglial dysfunction, ataxia, and Purkinje cell (PC) dendritic atrophy. Bergmann glia (BG), radial astrocytes essential for cerebellar development, are intimately intertwined with PCs, where they regulate synapse stability, functionality, and plasticity. BG damage is common to many neurodegenerative conditions and frequently associated with PC dysfunction and ataxia. Here, we report that, in CD mice, BG exhibit significant morphological alterations, decreased structural associations with PCs, loss of synaptic support proteins, and altered calcium dynamics. We also find that BG dysfunction predates cerebellar vacuolation and PC damage in CD mice. Previously, we developed an antisense oligonucleotide (ASO) therapy targeting Nat8l (N-acetyltransferase-8-like, "Nat8l ASO") that inhibits the production of NAA and reverses ataxia and PC atrophy in CD mice. Here, we show that Nat8l ASO administration in adult CD mice also leads to BG repair. Furthermore, blocking astroglial uptake of NAA is neuroprotective in astroglia-neuron cocultures exposed to elevated NAA. Our findings suggest that restoration of BG structural and functional integrity could be a mechanism for PC regeneration and improved motor function.

Changes to Astrocyte-associated Protein Expression at Different Timepoints of Cuprizone Treatment

Glial cells, including astrocytes, microglia, and oligodendrocytes, are brain cells that support and dynamically interact with neurons and each other. These intercellular dynamics undergo changes during stress and disease states. In response to most forms of stress, astrocytes will undergo some variation of activation, meaning upregulation in certain proteins expressed and secreted and either upregulations or downregulations to various constitutive and normal functions. While types of activation are many and contingent on the particular disturbance that triggers these changes, there are two main overarching categories that have been delineated thus far: A1 and A2. Named in the convention of microglial activation subtypes, and with the acknowledgement that the types are not completely distinct or completely comprehensive, the A1 subtype is generically associated with toxic and pro-inflammatory factors, and the A2 phenotype is broadly associated with anti-inflammatory and neurogenic factors. The present study served to measure and document dynamic changes in these subtypes at multiple timepoints using an established experimental model of cuprizone toxic demyelination. The authors found increases in proteins associated with both cell types at different timepoints, with protein increases in the A1 marker C3d and the A2 marker Emp1 in the cortex at one week and protein increases in Emp1 in the corpus callosum at three days and four weeks. There were also increases in Emp1 staining specifically colocalized with astrocyte staining in the corpus callosum at the same timepoints as the protein increases, and in the cortex weeks later at four weeks. C3d colocalization with astrocytes also increased most at four weeks. This indicates simultaneous increases of both types of activation as well as the likely existence of astrocytes expressing both markers. The authors also found the increase in two A1 associated proteins (TNF alpha and C3d) did not show a linear relationship in line with findings from other research and indicating a more complex relationship between cuprizone toxicity and astrocyte activation. The increases in TNF alpha and IFN gamma did not occur at timepoints preceding increases in C3d and Emp1, showing that other factors also precipitate the subtypes associated (A1 for C3d and A2 for Emp1). These findings add to the body of research showing the specific early timepoints at which A1 and A2 markers are most increased during the course of cuprizone treatment, including the fact that these increases can be non-linear in the case of Emp1. This provides additional information on optimal times for targeted interventions during the cuprizone model.

Serological response to vaccination in post-acute sequelae of COVID

BACKGROUND

Individuals with post-acute sequelae of COVID (PASC) may have a persistence in immune activation that differentiates them from individuals who have recovered from COVID without clinical sequelae. To investigate how humoral immune activation may vary in this regard, we compared patterns of vaccine-provoked serological response in patients with PASC compared to individuals recovered from prior COVID without PASC.

METHODS

We prospectively studied 245 adults clinically diagnosed with PASC and 86 adults successfully recovered from prior COVID. All participants had measures of humoral immunity to SARS-CoV-2 assayed before or after receiving their first-ever administration of COVID vaccination (either single-dose or two-dose regimen), including anti-spike (IgG-S and IgM-S) and anti-nucleocapsid (IgG-N) antibodies as well as IgG-S angiotensin-converting enzyme 2 (ACE2) binding levels. We used unadjusted and multivariable-adjusted regression analyses to examine the association of PASC compared to COVID-recovered status with post-vaccination measures of humoral immunity.

RESULTS

Individuals with PASC mounted consistently higher post-vaccination IgG-S antibody levels when compared to COVID-recovered (median log IgG-S 3.98 versus 3.74, P < 0.001), with similar results seen for ACE2 binding levels (median 99.1 versus 98.2, P = 0.044). The post-vaccination IgM-S response in PASC was attenuated but persistently unchanged over time (P = 0.33), compared to in COVID recovery wherein the IgM-S response expectedly decreased over time (P = 0.002). Findings remained consistent when accounting for demographic and clinical variables including indices of index infection severity and comorbidity burden.

CONCLUSION

We found evidence of aberrant immune response distinguishing PASC from recovered COVID. This aberrancy is marked by excess IgG-S activation and ACE2 binding along with findings consistent with a delayed or dysfunctional immunoglobulin class switching, all of which is unmasked by vaccine provocation. These results suggest that measures of aberrant immune response may offer promise as tools for diagnosing and distinguishing PASC from non-PASC phenotypes, in addition to serving as potential targets for intervention.

Diagnostic Performance and Advanced Imaging Reduction With Digital Tomosynthesis in Scaphoid Fracture Management

BACKGROUND

Management of scaphoid fractures often requires advanced imaging to achieve accurate diagnoses and appropriate treatment. Digital tomosynthesis (DTS) is a cross-sectional imaging modality that may be used to substitute magnetic resonance imaging or computed tomographic scans. The purpose of this study is to: (1) determine the diagnostic accuracy of DTS in occult scaphoid fractures; and (2) report on the reduction of other advanced imaging when using DTS.

METHODS

From May 2014 to October 2017, the charts of all patients who underwent scaphoid tomogram were retrospectively reviewed. The diagnostic accuracy of DTS for occult fracture was compared with 2-week follow-up plain films. To measure the reduction in utilization of advanced imaging, it was determined whether DTS eliminated the need for advanced imaging by providing adequate information regarding the clinical question.

RESULTS

A total of 78 patients underwent scaphoid tomography in this time frame: 39 for occult fracture, 33 for fracture union, 5 for fracture morphology, and 1 for hardware positioning. For the detection of occult fracture, DTS had a sensitivity of 100%, specificity of 83%, positive predictive value of 64%, and negative predictive value of 100%. Advanced imaging was not used in 35 of the remaining 39 patients based on the results obtained by DTS. In patients who did receive advanced imaging, 83% of tomograms provided conclusive diagnostic information.

CONCLUSIONS

Digital tomosynthesis increases the diagnostic sensitivity of occult scaphoid fractures, reducing unnecessary immobilization and advanced imaging. Digital tomosynthesis provides clinical detail beyond plain film, which reduces the need to obtain advanced imaging when assessing union, fracture pattern, and hardware placement.

Disparities in Geographic Access to Cardiac Rehabilitation in Los Angeles County

Background Exercise-based cardiac rehabilitation (CR) is known to reduce morbidity and mortality for patients with cardiac conditions. Sociodemographic disparities in accessing CR persist and could be related to the distance between where patients live and where CR facilities are located. Our objective is to determine the association between sociodemographic characteristics and geographic proximity to CR facilities. Methods and Results We identified actively operating CR facilities across Los Angeles County and used multivariable Poisson regression to examine the association between sociodemographic characteristics of residential proximity to the nearest CR facility. We also calculated the proportion of residents per area lacking geographic proximity to CR facilities across sociodemographic characteristics, from which we calculated prevalence ratios. We found that racial and ethnic minorities, compared with non-Hispanic White individuals, more frequently live ≥5 miles from a CR facility. The greatest geographic disparity was seen for non-Hispanic Black individuals, with a 2.73 (95% CI, 2.66-2.79) prevalence ratio of living at least 5 miles from a CR facility. Notably, the municipal region with the largest proportion of census tracts comprising mostly non-White residents (those identifying as Hispanic or a race other than White), with median annual household income <$60 000, contained no CR facilities despite ranking among the county's highest in population density. Conclusions Racial, ethnic, and socioeconomic characteristics are significantly associated with lack of geographic proximity to a CR facility. Interventions targeting geographic as well as nongeographic factors may be needed to reduce disparities in access to exercise-based CR programs. Such interventions could increase the potential of CR to benefit patients at high risk for developing adverse cardiovascular outcomes.

Symptomology following mRNA vaccination against SARS-CoV-2

Despite demonstrated efficacy of vaccines against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of coronavirus disease-2019 (COVID-19), widespread hesitancy to vaccination persists. Improved knowledge regarding frequency, severity, and duration of vaccine-associated symptoms may help reduce hesitancy. In this prospective observational study, we studied 1032 healthcare workers who received both doses of the Pfizer-BioNTech SARS-CoV-2 mRNA vaccine and completed post-vaccine symptom surveys both after dose 1 and after dose 2. We defined appreciable post-vaccine symptoms as those of at least moderate severity and lasting at least 2 days. We found that symptoms were more frequent following the second vaccine dose than the first (74% vs. 60%, P < 0.001), with >80% of all symptoms resolving within 2 days. The most common symptom was injection site pain, followed by fatigue and malaise. Overall, 20% of participants experienced appreciable symptoms after dose 1 and 30% after dose 2. In multivariable analyses, female sex was associated with greater odds of appreciable symptoms after both dose 1 (OR, 95% CI 1.73, 1.19-2.51) and dose 2 (1.76, 1.28-2.42). Prior COVID-19 was also associated with appreciable symptoms following dose 1, while younger age and history of hypertension were associated with appreciable symptoms after dose 2. We conclude that most post-vaccine symptoms are reportedly mild and last <2 days. Appreciable post-vaccine symptoms are associated with female sex, prior COVID-19, younger age, and hypertension. This information can aid clinicians in advising patients on the safety and expected symptomatology associated with vaccination.

Ablating the Transporter Sodium-Dependent Dicarboxylate Transporter 3 Prevents Leukodystrophy in Canavan Disease Mice

Canavan disease is caused by ASPA mutations that diminish brain aspartoacylase activity, and it is characterized by excessive brain storage of the aspartoacylase substrate, N-acetyl-l-aspartate (NAA), and by astroglial and intramyelinic vacuolation. Astroglia and the arachnoid mater express sodium-dependent dicarboxylate transporter (NaDC3), encoded by SLC13A3, a sodium-coupled transporter for NAA and other dicarboxylates. Constitutive Slc13a3 deletion in aspartoacylase-deficient Canavan disease mice prevents brain NAA overaccumulation, ataxia, and brain vacuolation. ANN NEUROL 2021;90:845-850.

The BHMT-betaine methylation pathway epigenetically modulates oligodendrocyte maturation

Research into the epigenome is of growing importance as a loss of epigenetic control has been implicated in the development of neurodegenerative diseases. Previous studies have implicated aberrant DNA and histone methylation in multiple sclerosis (MS) disease pathogenesis. We have previously reported that the methyl donor betaine is depleted in MS and is linked to changes in histone H3 trimethylation (H3K4me3) in neurons. We have also shown that betaine increases histone methyltransferase activity by activating chromatin bound betaine homocysteine S-methyltransferase (BHMT). Here, we investigated the role of the BHMT-betaine methylation pathway in oligodendrocytes. Immunocytochemistry in the human MO3.13 cell line, primary rat oligodendrocytes, and tissue from MS postmortem brain confirmed the presence of the BHMT enzyme in the nucleus in oligodendrocytes. BHMT expression is increased 2-fold following oxidative insult, and qRT-PCR demonstrated that betaine can promote an increase in expression of oligodendrocyte maturation genes SOX10 and NKX-2.2 under oxidative conditions. Chromatin fractionation provided evidence of a direct interaction of BHMT on chromatin and co-IP analysis indicates an interaction between BHMT and DNMT3a. Our data show that both histone and DNA methyltransferase activity are increased following betaine administration. Betaine effects were shown to be dependent on BHMT expression following siRNA knockdown of BHMT. This is the first report of BHMT expression in oligodendrocytes and suggests that betaine acts through BHMT to modulate histone and DNA methyltransferase activity on chromatin. These data suggest that methyl donor availability can impact epigenetic changes and maturation in oligodendrocytes.

Seroprevalence of antibodies to SARS-CoV-2 in healthcare workers: a cross-sectional study

OBJECTIVE

We sought to determine the extent of SARS-CoV-2 seroprevalence and the factors associated with seroprevalence across a diverse cohort of healthcare workers.

DESIGN

Observational cohort study of healthcare workers, including SARS-CoV-2 serology testing and participant questionnaires.

SETTINGS

A multisite healthcare delivery system located in Los Angeles County.

PARTICIPANTS

A diverse and unselected population of adults (n=6062) employed in a multisite healthcare delivery system located in Los Angeles County, including individuals with direct patient contact and others with non-patient-oriented work functions.

MAIN OUTCOMES

Using Bayesian and multivariate analyses, we estimated seroprevalence and factors associated with seropositivity and antibody levels, including pre-existing demographic and clinical characteristics; potential COVID-19 illness-related exposures; and symptoms consistent with COVID-19 infection.

RESULTS

We observed a seroprevalence rate of 4.1%, with anosmia as the most prominently associated self-reported symptom (OR 11.04, p<0.001) in addition to fever (OR 2.02, p=0.002) and myalgias (OR 1.65, p=0.035). After adjusting for potential confounders, seroprevalence was also associated with Hispanic ethnicity (OR 1.98, p=0.001) and African-American race (OR 2.02, p=0.027) as well as contact with a COVID-19-diagnosed individual in the household (OR 5.73, p<0.001) or clinical work setting (OR 1.76, p=0.002). Importantly, African-American race and Hispanic ethnicity were associated with antibody positivity even after adjusting for personal COVID-19 diagnosis status, suggesting the contribution of unmeasured structural or societal factors.

CONCLUSION AND RELEVANCE

The demographic factors associated with SARS-CoV-2 seroprevalence among our healthcare workers underscore the importance of exposure sources beyond the workplace. The size and diversity of our study population, combined with robust survey and modelling techniques, provide a vibrant picture of the demographic factors, exposures and symptoms that can identify individuals with susceptibility as well as potential to mount an immune response to COVID-19.

Increased blood-brain barrier hyperpermeability coincides with mast cell activation early under cuprizone administration

The cuprizone induced animal model of demyelination is characterized by demyelination in many regions of the brain with high levels of demyelination in the corpus callosum as well as changes in neuronal function by 4–6 weeks of exposure. The model is used as a tool to study demyelination and subsequent degeneration as well as therapeutic interventions on these effects. Historically, the cuprizone model has been shown to contain no alterations to blood-brain barrier integrity, a key feature in many diseases that affect the central nervous system. Cuprizone is generally administered for 4–6 weeks to obtain maximal demyelination and degeneration. However, emerging evidence has shown that the effects of cuprizone on the brain may occur earlier than measurable gross demyelination. This study sought to investigate changes to blood-brain barrier permeability early in cuprizone administration. Results showed an increase in blood-brain barrier permeability and changes in tight junction protein expression as early as 3 days after beginning cuprizone treatment. These changes preceded glial morphological activation and demyelination known to occur during cuprizone administration. Increases in mast cell presence and activity were measured alongside the increased permeability implicating mast cells as a potential source for the blood-brain barrier disruption. These results provide further evidence of blood-brain barrier alterations in the cuprizone model and a target of therapeutic intervention in the prevention of cuprizone-induced pathology. Understanding how mast cells become activated under cuprizone and if they contribute to blood-brain barrier alterations may give further insight into how and when the blood-brain barrier is affected in CNS diseases. In summary, cuprizone administration causes an increase in blood-brain barrier permeability and this permeability coincides with mast cell activation.

Betaine restores epigenetic control and supports neuronal mitochondria in the cuprizone mouse model of multiple sclerosis

Methionine metabolism is dysregulated in multiple sclerosis (MS). The methyl donor betaine is depleted in the MS brain where it is linked to changes in levels of histone H3 trimethylated on lysine 4 (H3K4me3) and mitochondrial impairment. We investigated the effects of replacing this depleted betaine in the cuprizone mouse model of MS. Supplementation with betaine restored epigenetic control and alleviated neurological disability in cuprizone mice. Betaine increased the methylation potential (SAM/SAH ratio), levels of H3K4me3, enhanced neuronal respiration, and prevented axonal damage. We show that the methyl donor betaine and the betaine homocysteine methyltransferase (BHMT) enzyme can act in the nucleus to repair epigenetic control and activate neuroprotective transcriptional programmes. ChIP-seq data suggest that BHMT acts on chromatin to increase the SAM/SAH ratio and histone methyltransferase activity locally to increase H3K4me3 and activate gene expression that supports neuronal energetics. These data suggest that the methyl donor betaine may provide neuroprotection in MS where mitochondrial impairment damages axons and causes disability.

Antisense Oligonucleotide Reverses Leukodystrophy in Canavan Disease Mice

Marked elevation in the brain concentration of N-acetyl-L-aspartate (NAA) is a characteristic feature of Canavan disease, a vacuolar leukodystrophy resulting from deficiency of the oligodendroglial NAA-cleaving enzyme aspartoacylase. We now demonstrate that inhibiting NAA synthesis by intracisternal administration of a locked nucleic acid antisense oligonucleotide to young-adult aspartoacylase-deficient mice reverses their pre-existing ataxia and diminishes cerebellar and thalamic vacuolation and Purkinje cell dendritic atrophy. Ann Neurol 2020;87:480-485.

Trends in Urgent Care Utilization Following Ankle Fracture Fixation

BACKGROUND:

The Centers for Medicare and Medicaid services (CMS) have implemented initiatives to improve postdischarge care and reduce unnecessary readmissions. Readmissions within 30 days are frequent and represent an economic burden on both patients and the healthcare system. The aim of this study was to evaluate the frequency and causes for urgent care visits within 30 days of discharge after ankle open reduction and internal fixation (ORIF) and determine factors correlated with such visits.

METHODS:

This was a retrospective analysis of prospectively collected data. All patients who underwent ankle ORIF at our institution between July 1, 2016, and June 30, 2017, were included. Patients were identified using Current Procedural Terminology (CPT) codes for ankle ORIF. Patients' demographics including age, sex, race, body mass index, occupation, insurance payer, and comorbidities were documented.

RESULTS:

Thirty-five patients (10.51%) had urgent care visits within 30 days of discharge. Patients presented at a mean of 11.8 days after the day of surgery. Sixteen patients (45.71%) had cast/splint-related issues, 7 (20%) presented with pain, and 7 (20%) with increased operative site drainage. Univariate analysis demonstrated a statistically significant association between postoperative urgent care visits and patients with diabetes ( P = .03) or underlying psychiatric disorders ( P = .03).

CONCLUSION:

In this population study of patients undergoing ankle fracture surgery, we found that the rate of urgent care visits within 30 days of discharge exceeded the rate of inpatient readmission. Additionally, patients with diabetes and psychiatric disorders were significantly more likely to present to an urgent care facility postoperatively, potentially accounting for increased expenditures of the healthcare system.

LEVEL OF EVIDENCE:

Level III, comparative series.

The etiology, evaluation, and management of plantar fibromatosis

Plantar fibromatosis (Ledderhose disease) is a rare, benign, hyperproliferative fibrous tissue disorder resulting in the formation of nodules along the plantar fascia. This condition can be locally aggressive, and often results in pain, functional disability, and decreased quality of life. Diagnosis is primarily clinical, but MRI and ultrasound are useful confirmatory adjuncts. Given the benign nature of this condition, treatment has historically involved symptomatic management. A multitude of conservative treatment strategies supported by varying levels of evidence have been described mostly in small-scale trials. These therapies include steroid injections, verapamil, radiation therapy, extracorporeal shock wave therapy, tamoxifen, and collagenase. When conservative measures fail, surgical removal of fibromas and adjacent plantar fascia is often done, although recurrence is common. This review aims to provide a broad overview of the clinical features of this disease as well as the current treatment strategies being employed in the management of this condition.