Axon-like active signal transmission.

Any electrical signal propagating in a metallic conductor loses amplitude due to the natural resistance of the metal. Compensating for such losses presently requires repeatedly breaking the conductor and interposing amplifiers that consume and regenerate the signal. This century-old primitive severely constrains the design and performance of modern interconnect-dense chips1. Here we present a fundamentally different primitive based on semi-stable edge of chaos (EOC)2,3, a long-theorized but experimentally elusive regime that underlies active (self-amplifying) transmission in biological axons4,5. By electrically accessing the spin crossover in LaCoO3, we isolate semi-stable EOC, characterized by small-signal negative resistance and amplification of perturbations6,7. In a metallic line atop a medium biased at EOC, a signal input at one end exits the other end amplified, without passing through a separate amplifying component. While superficially resembling superconductivity, active transmission offers controllably amplified time-varying small-signal propagation at normal temperature and pressure, but requires an electrically energized EOC medium. Operando thermal mapping reveals the mechanism of amplification-bias energy of the EOC medium, instead of fully dissipating as heat, is partly used to amplify signals in the metallic line, thereby enabling spatially continuous active transmission, which could transform the design and performance of complex electronic chips.

A conditional multi-label model to improve prediction of a rare outcome: An illustration predicting autism diagnosis.

OBJECTIVE: This study aimed to develop a novel approach using routinely collected electronic health records (EHRs) data to improve the prediction of a rare event. We illustrated this using an example of improving early prediction of an autism diagnosis, given its low prevalence, by leveraging correlations between autism and other neurodevelopmental conditions (NDCs). METHODS: To achieve this, we introduced a conditional multi-label model by merging conditional learning and multi-label methodologies. The conditional learning approach breaks a hard task into more manageable pieces in each stage, and the multi-label approach utilizes information from related neurodevelopmental conditions to learn predictive latent features. The study involved forecasting autism diagnosis by age 5.5 years, utilizing data from the first 18 months of life, and the analysis of feature importance correlations to explore the alignment within the feature space across different conditions. RESULTS: Upon analysis of health records from 18,156 children, we are able to generate a model that predicts a future autism diagnosis with moderate performance (AUROC=0.76). The proposed conditional multi-label method significantly improves predictive performance with an AUROC of 0.80 (p < 0.001). Further examination shows that both the conditional and multi-label approach alone provided marginal lift to the model performance compared to a one-stage one-label approach. We also demonstrated the generalizability and applicability of this method using simulated data with high correlation between feature vectors for different labels. CONCLUSION: Our findings underscore the effectiveness of the developed conditional multi-label model for early prediction of an autism diagnosis. The study introduces a versatile strategy applicable to prediction tasks involving limited target populations but sharing underlying features or etiology among related groups.

ct2vl: A Robust Public Resource for Converting SARS-CoV-2 Ct Values to Viral Loads.

The amount of SARS-CoV-2 in a sample is often measured using Ct values. However, the same Ct value may correspond to different viral loads on different platforms and assays, making them difficult to compare from study to study. To address this problem, we developed ct2vl, a Python package that converts Ct values to viral loads for any RT-qPCR assay/platform. The method is novel in that it is based on determining the maximum PCR replication efficiency, as opposed to fitting a sigmoid (S-shaped) curve relating signal to cycle number. We calibrated ct2vl on two FDA-approved platforms and validated its performance using reference-standard material, including sensitivity analysis. We found that ct2vl-predicted viral loads were highly accurate across five orders of magnitude, with 1.6-fold median error (for comparison, viral loads in clinical samples vary over 10 orders of magnitude). The package has 100% test coverage. We describe installation and usage both from the Unix command-line and from interactive Python environments. ct2vl is freely available via the Python Package Index (PyPI). It facilitates conversion of Ct values to viral loads for clinical investigators, basic researchers, and test developers for any RT-qPCR platform. It thus facilitates comparison among the many quantitative studies of SARS-CoV-2 by helping render observations in a natural, universal unit of measure.

Downregulation of IRF8 in alveolar macrophages by G-CSF promotes metastatic tumor progression.

Tissue-resident macrophages (TRMs) are abundant immune cells within pre-metastatic sites, yet their functional contributions to metastasis remain incompletely understood. Here, we show that alveolar macrophages (AMs), the main TRMs of the lung, are susceptible to downregulation of the immune stimulatory transcription factor IRF8, impairing anti-metastatic activity in models of metastatic breast cancer. G-CSF is a key tumor-associated factor (TAF) that acts upon AMs to reduce IRF8 levels and facilitate metastasis. Translational relevance of IRF8 downregulation was observed among macrophage precursors in breast cancer and a CD68hiIRF8loG-CSFhi gene signature suggests poorer prognosis in triple-negative breast cancer (TNBC), a G-CSF-expressing subtype. Our data highlight the underappreciated, pro-metastatic roles of AMs in response to G-CSF and identify the contribution of IRF8-deficient AMs to metastatic burden. AMs are an attractive target of local neoadjuvant G-CSF blockade to recover anti-metastatic activity.

Spontaneous Remission of Acquired Generalized Lipodystrophy Presenting in the Postpartum Period.

Acquired generalized lipodystrophy (AGL) is a rare condition characterized by the diffuse loss of adipose tissue resulting in hyperglycemia, severe insulin resistance, and sequelae of metabolic disease. Here, we report the case of a 32-year-old woman who developed uncontrolled hyperglycemia and significant weight loss within 2 months postpartum. Upon endocrine evaluation, she was found to have generalized loss of adiposity, hypoleptinemia, and persistent hyperglycemia despite aggressive insulin administration. Glycemic response was obtained with U-500 intramuscular insulin, pioglitazone, and metformin-sitagliptin. At 14 months postpartum, the patient achieved spontaneous remission with normoglycemia off medication and restoration of adipose tissue deposition. Autoimmune workup revealed positive antinuclear antibodies (ANA) and anti-U1-ribonucleoprotein (anti-U1-RNP) titers, suggestive of an autoimmune etiology to her condition. This case of AGL represents the first reported case of spontaneous remission and the first to develop in the postpartum period.

The Current Status of Awake Endoscopic Surgery: A Systematic Review and Meta-Analysis.

OBJECTIVE: To examine the use of local anesthesia and/or conscious sedation in endoscopic spine procedures within the past decade. METHODS: This systematic review abided by PRISMA guidelines. Embase, PubMed, Google Scholar, and Cochrane databases were searched for post-2011 articles with patients >18 years old, lumbar/cervical percutaneous endoscopic spine procedures using local/awake anesthesia, and patient/surgical outcomes. Reviews, book chapters, single case reports, or small case series (n ≤15 patients) were excluded. Scoring systems of the National Institutes of Health quality assessment tool, Newcastle-Ottawa Scale, and Cochrane Risk of Bias evaluated interventional case series, comparative studies, and randomized control trials, respectively. RESULTS: Twenty-six articles were included, with 4 studies comparing general and local anesthesia. Of 2113 total patients, 1873 patients received local anesthesia. Significant improvements were seen in pain and disability scores. Studies that included MacNab scores showed that 96% of patients rated their postoperative satisfaction as excellent to good. Subanalysis of comparative studies showed a reduced risk of surgical/major medical complications and a slight increased risk for minor medical complications among awake spine patients. Length of stay was shorter for patients receiving local anesthesia. CONCLUSIONS: The current systematic review and meta-analysis shows that use of local anesthesia is a safe and effective alternative to general anesthesia among different endoscopic spinal procedures. Although awake spine surgery is associated with a decreased risk of severe complications, lower revision rates, and higher postoperative satisfaction, more robust studies involving larger cohorts of patients are needed to evaluate the true impact of awake spine surgery on outcomes.

DichroIDP: a method for analyses of intrinsically disordered proteins using circular dichroism spectroscopy.

Intrinsically disordered proteins (IDPs) are comprised of significant numbers of residues that form neither helix, sheet, nor any other canonical type of secondary structure. They play important roles in a broad range of biological processes, such as molecular recognition and signalling, largely due to their chameleon-like ability to change structure from unordered when free in solution to ordered when bound to partner molecules. Circular dichroism (CD) spectroscopy is a widely-used method for characterising protein secondary structures, but analyses of IDPs using CD spectroscopy have suffered because the methods and reference datasets used for the empirical determination of secondary structures do not contain adequate representations of unordered structures. This work describes the creation, validation and testing of a standalone Windows-based application, DichroIDP, and a new reference dataset, IDP175, which is suitable for analyses of proteins containing significant amounts of disordered structure. DichroIDP enables secondary structure determinations of IDPs and proteins containing intrinsically disordered regions.

Nodular Sarcoid Myositis Treated With Hydroxychloroquine Monotherapy.

Clinically significant granulomatous inflammation of skeletal muscle in sarcoidosis is rare. Glucocorticoids are generally considered the first-line treatment of sarcoidosis, but due to their side effect profile, the addition of steroid-sparing regimens has become increasingly more common. We report a patient with nodular sarcoid myositis who was successfully treated with antimalarial hydroxychloroquine alone. Whereas antimalarials have been reported to be an effective treatment of various organ involvement in sarcoidosis, to our knowledge, this is the first report of hydroxychloroquine monotherapy successfully treating nodular sarcoid myositis. Hydroxychloroquine monotherapy may be a reasonable initial treatment option for nodular sarcoid myositis and other forms of muscular sarcoidosis, as well as for other non-acute organ-threatening manifestations of the disease.

Mitochondrial dysfunction and mitophagy defects in LRRK2-R1441C Parkinson's disease models.

Mutations in the Leucine-Rich Repeat Kinase 2 (LRRK2) gene have been identified as one of the most common genetic causes of Parkinson's disease (PD). The LRRK2 PD-associated mutations LRRK2G2019S and LRRK2R1441C, located in the kinase domain and in the ROC-COR domain, respectively, have been demonstrated to impair mitochondrial function. Here, we sought to further our understanding of mitochondrial health and mitophagy by integrating data from LRRK2R1441C rat primary cortical and human induced pluripotent stem cell-derived dopamine (iPSC-DA) neuronal cultures as models of PD. We found that LRRK2R1441C neurons exhibit decreased mitochondrial membrane potential, impaired mitochondrial function and decreased basal mitophagy levels. Mitochondrial morphology was altered in LRRK2R1441C iPSC-DA but not in cortical neuronal cultures or aged striatal tissue, indicating a cell-type-specific phenotype. Additionally, LRRK2R1441C but not LRRK2G2019S neurons demonstrated decreased levels of the mitophagy marker pS65Ub in response to mitochondrial damage, which could disrupt degradation of damaged mitochondria. This impaired mitophagy activation and mitochondrial function were not corrected by the LRRK2 inhibitor MLi-2 in LRRK2R1441C iPSC-DA neuronal cultures. Furthermore, we demonstrate LRRK2 interaction with MIRO1, a protein necessary to stabilize and to anchor mitochondria for transport, occurs at mitochondria, in a genotype-independent manner. Despite this, we found that degradation of MIRO1 was impaired in LRRK2R1441C cultures upon induced mitochondrial damage, suggesting a divergent mechanism from the LRRK2G2019S mutation.

ß-Catenin signaling in alveolar macrophages enhances lung metastasis through a TNF-dependent mechanism.

The main cause of malignancy-related mortality is metastasis. Although metastatic progression is driven by diverse tumor-intrinsic mechanisms, there is a growing appreciation for the contribution of tumor-extrinsic elements of the tumor microenvironment, especially macrophages, which correlate with poor clinical outcomes. Macrophages consist of bone marrow-derived and tissue-resident populations. In contrast to bone marrow-derived macrophages, the transcriptional pathways that govern the pro-metastatic activities of tissue-resident macrophages (TRMs) remain less clear. Alveolar macrophages (AMs) are a TRM population with critical roles in tissue homeostasis and metastasis. Wnt/ß-catenin signaling is a hallmark of cancer and has been identified as a pathologic regulator of AMs in infection. We tested the hypothesis that ß-catenin expression in AMs enhances metastasis in solid tumor models. Using a genetic ß-catenin gain-of-function approach, we demonstrated that (a) enhanced ß-catenin in AMs heightened lung metastasis; (b) ß-catenin activity in AMs drove a dysregulated inflammatory program strongly associated with Tnf expression; and (c) localized TNF-α blockade abrogated this metastatic outcome. Last, ß-catenin gene CTNNB1 and TNF expression levels were positively correlated in AMs of patients with lung cancer. Overall, our findings revealed a Wnt/ß-catenin/TNF-α pro-metastatic axis in AMs with potential therapeutic implications against tumors refractory to the antineoplastic actions of TNF-α.

Validation of Neck Disability Index Severity among Patients Receiving One or Two-Level Anterior Cervical Surgery.

STUDY DESIGN: Retrospective cohort. PURPOSE: To evaluate the validity of established severity thresholds for Neck Disability Index (NDI) among patients undergoing anterior cervical discectomy and fusion (ACDF) or cervical disc arthroplasty (CDA). OVERVIEW OF LITERATURE: Few studies have examined the validity of established NDI threshold values among patients undergoing ACDF or CDA. METHODS: A surgical database was reviewed to identify patients undergoing cervical spine procedures. Demographics, operative characteristics, comorbidities, NDI, Visual Analog Scale (VAS), and 12-item Short Form (SF-12) physical and mental composite scores (PCS and MCS) were recorded. NDI severity was categorized using previously established threshold values. Improvement from preoperative scores at each postoperative timepoint and convergent validity of NDI was evaluated. Discriminant validity of NDI was evaluated against VAS neck and arm and SF-12 PCS and MCS. RESULTS: All 290 patients included in the study demonstrated significant improvements from baseline values for all patient-reported outcome measures (PROMs) at all postoperative timepoints (p<0.001) except SF-12 MCS at 2 years (p =0.393). NDI showed a moderate- to-strong correlation (r≥0.419) at most timepoints for VAS neck, VAS arm, SF-12 PCS, and SF-12 MCS (p<0.001, all). NDI severity categories demonstrated significant differences in mean VAS neck, VAS arm, SF-12 PCS, and SF-12 MCS at all timepoints (p<0.001, all). Differences between NDI severity groups were not uniform for all PROMs. VAS neck values demonstrated significant intergroup differences at most timepoints, whereas SF-12 MCS showed significantly different values between most severity groups. CONCLUSIONS: Neck disability is strongly correlated with neck and arm pain, physical function, and mental health and demonstrates worse outcomes with increasing severity. Previously established severity categories may be more applicable to pain than physical function or mental health and may be more uniformly applied preoperatively for cervical spine patients.

Gene Expression Profiles in Cutaneous Oncology.

Skin cancer is highly curable under most circumstances; however, locally advanced or metastatic disease historically has poor outcomes and limited treatment options. Treatment has recently been advanced by the discovery of pertinent genes influencing pathogenesis and further revolutionized by the advent of specific gene expression profiles (GEPs). GEPs have been developed to help refine current diagnostic and prognostic strategies used in skin cancer with the goal to ultimately help guide management and treatment modalities to improve patient care. This article provides a high-level review of diagnostic and prognostic GEPs that have been developed specifically for squamous cell carcinoma and melanoma.

Fluorescence-Based NAPE-PLD Activity Assay.

N-Acylphosphatidylethanolamine phospholipase D (NAPE-PLD) is regarded as the principal enzyme that generates N-acylethanolamines (NAEs), a family of signaling lipids that includes the endocannabinoid anandamide. To investigate the biological function and biosynthesis of NAEs, we sought to develop potent NAPE-PLD inhibitors. To this aim, we utilized a high-throughput screening-compatible NAPE-PLD activity assay, which uses the fluorescence-quenched substrate PED6. This assay conveniently uses membrane fractions of NAPE-PLD overexpressing HEK293T cell lysates, thus avoiding the need for protein purification. Here, we give a detailed description of the NAPE-PLD PED6 fluorescence activity assay, which has increased throughput compared to previous radioactivity- or mass-spectrometry-based assays.

Rheumatologic associations of microscopic colitis: A narrative review.

Extraintestinal manifestations (EIMs) are frequent complications of the classical inflammatory bowel diseases, Crohn's disease and ulcerative colitis. However, in addition to the classical diseases, there is a spectrum of conditions, often termed 'microscopic colitis' (MC), in which EIMs are less well described. Our objective was to review the literature regarding the EIMs complicating MC and describe their association with systemic autoimmune rheumatic diseases. A comprehensive search and review of peer-reviewed English-language and international journals and reports was completed based on key terms, including 'microscopic colitis', 'lymphocytic colitis', 'collagenous colitis', 'inflammatory bowel disease', and 'extraintestinal manifestations', and the specific disease associations utilizing the PubMed Central database and MEDLINE. A broad spectrum of rheumatologic manifestations has been reported in patients with MC. The identification of rheumatoid arthritis and limited scleroderma as comorbidities with MC was noteworthy. Inflammatory arthropathy was frequently seen in MC, usually preceding or occurring in conjunction with the onset of gastrointestinal symptoms. A variety of presentations of associated arthritis were reported: migratory, symmetric or asymmetric, peripheral or axial, oligoarticular or polyarticular, and erosive or non-erosive. There was a high incidence of autoantibodies in these patients, supporting a potential autoimmune association. On the basis of these anecdotal reports, we would suggest the development of a clinical registry to help define the incidence of EIMs and systemic autoimmune rheumatic diseases among MC patients to help elucidate shared predispositions, pathogenic mechanisms, and therapeutic opportunities.

Anandamide and other N-acylethanolamines: A class of signaling lipids with therapeutic opportunities.

N-acylethanolamines (NAEs), including N-palmitoylethanolamine (PEA), N-oleoylethanolamine (OEA), N-arachidonoylethanolamine (AEA, anandamide), N-docosahexaenoylethanolamine (DHEA, synaptamide) and their oxygenated metabolites are a lipid messenger family with numerous functions in health and disease, including inflammation, anxiety and energy metabolism. The NAEs exert their signaling role through activation of various G protein-coupled receptors (cannabinoid CB1 and CB2 receptors, GPR55, GPR110, GPR119), ion channels (TRPV1) and nuclear receptors (PPAR-α and PPAR-γ) in the brain and periphery. The biological role of the oxygenated NAEs, such as prostamides, hydroxylated anandamide and DHEA derivatives, are less studied. Evidence is accumulating that NAEs and their oxidative metabolites may be aberrantly regulated or are associated with disease severity in obesity, metabolic syndrome, cancer, neuroinflammation and liver cirrhosis. Here, we comprehensively review NAE biosynthesis and degradation, their metabolism by lipoxygenases, cyclooxygenases and cytochrome P450s and the biological functions of these signaling lipids. We discuss the latest findings and therapeutic potential of modulating endogenous NAE levels by inhibition of their degradation, which is currently under clinical evaluation for neuropsychiatric disorders. We also highlight NAE biosynthesis inhibition as an emerging topic with therapeutic opportunities in endocannabinoid and NAE signaling.

greylock: A Python Package for Measuring The Composition of Complex Datasets.

Machine-learning datasets are typically characterized by measuring their size and class balance. However, there exists a richer and potentially more useful set of measures, termed diversity measures, that incorporate elements' frequencies and between-element similarities. Although these have been available in the R and Julia programming languages for other applications, they have not been as readily available in Python, which is widely used for machine learning, and are not easily applied to machine-learning-sized datasets without special coding considerations. To address these issues, we developed greylock, a Python package that calculates diversity measures and is tailored to large datasets. greylock can calculate any of the frequency-sensitive measures of Hill's D-number framework, and going beyond Hill, their similarity-sensitive counterparts (Greylock is a mountain). greylock also outputs measures that compare datasets (beta diversities). We first briefly review the D-number framework, illustrating how it incorporates elements' frequencies and between-element similarities. We then describe greylock's key features and usage. We end with several examples - immunomics, metagenomics, computational pathology, and medical imaging - illustrating greylock's applicability across a range of dataset types and fields.

Inhibiting the biogenesis of myeloid-derived suppressor cells enhances immunotherapy efficacy against mammary tumor progression.

While immune checkpoint inhibitors (ICIs) have transformed the therapeutic landscape in oncology, they are effective in select subsets of patients. Efficacy may be limited by tumor-driven immune suppression, of which 1 key mechanism is the development of myeloid-derived suppressor cells (MDSCs). A fundamental gap in MDSC therapeutics is the lack of approaches that target MDSC biogenesis. We hypothesized that targeting MDSC biogenesis would mitigate MDSC burden and bolster tumor responses to ICIs. We tested a class of agents, dihydroorotate dehydrogenase (DHODH) inhibitors, that have been previously shown to restore the terminal differentiation of leukemic myeloid progenitors. DHODH inhibitors have demonstrated preclinical safety and are under clinical study for hematologic malignancies. Using mouse models of mammary cancer that elicit robust MDSC responses, we demonstrated that the DHODH inhibitor brequinar (a) suppressed MDSC production from early-stage myeloid progenitors, which was accompanied by enhanced myeloid maturation; (b) augmented the antitumor and antimetastatic activities of programmed cell death 1-based (PD-1-based) ICI therapy in ICI-resistant mammary cancer models; and (c) acted in concert with PD-1 blockade through modulation of MDSC and CD8+ T cell responses. Moreover, brequinar facilitated myeloid maturation and inhibited immune-suppressive features in human bone marrow culture systems. These findings advance the concept of MDSC differentiation therapy in immuno-oncology.

Tristetraprolin limits age-related expansion of myeloid-derived suppressor cells.

Aging results in enhanced myelopoiesis, which is associated with an increased prevalence of myeloid leukemias and the production of myeloid-derived suppressor cells (MDSCs). Tristetraprolin (TTP) is an RNA binding protein that regulates immune-related cytokines and chemokines by destabilizing target mRNAs. As TTP expression is known to decrease with age in myeloid cells, we used TTP-deficient (TTPKO) mice to model aged mice to study TTP regulation in age-related myelopoiesis. Both TTPKO and myeloid-specific TTPKO (cTTPKO) mice had significant increases in both MDSC subpopulations M-MDSCs (CD11b+Ly6ChiLy6G-) and PMN-MDSCs (CD11b+Ly6CloLy6G+), as well as macrophages (CD11b+F4/80+) in the spleen and mesenteric lymph nodes; however, no quantitative changes in MDSCs were observed in the bone marrow. In contrast, gain-of-function TTP knock-in (TTPKI) mice had no change in MDSCs compared with control mice. Within the bone marrow, total granulocyte-monocyte progenitors (GMPs) and monocyte progenitors (MPs), direct antecedents of M-MDSCs, were significantly increased in both cTTPKO and TTPKO mice, but granulocyte progenitors (GPs) were significantly increased only in TTPKO mice. Transcriptomic analysis of the bone marrow myeloid cell populations revealed that the expression of CC chemokine receptor 2 (CCR2), which plays a key role in monocyte mobilization to inflammatory sites, was dramatically increased in both cTTPKO and TTPKO mice. Concurrently, the concentration of CC chemokine ligand 2 (CCL2), a major ligand of CCR2, was high in the serum of cTTPKO and TTPKO mice, suggesting that TTP impacts the mobilization of M-MDSCs from the bone marrow to inflammatory sites during aging via regulation of the CCR2-CCL2 axis. Collectively, these studies demonstrate a previously unrecognized role for TTP in regulating age-associated myelopoiesis through the expansion of specific myeloid progenitors and M-MDSCs and their recruitment to sites of injury, inflammation, or other pathologic perturbations.

Longitudinal efficacy of acellular dermal allograft following superior capsular reconstruction of irreparable rotator cuff tears.

Background: Superior capsular reconstruction (SCR) remains an option for irreparable rotator cuff tears, especially for active patients. While fascia lata grafts were first used with SCRs, acellular dermal allografts have demonstrated similar postoperative outcomes and complication rates. Few studies report long-term clinical outcomes following use of acellular dermal allografts. The aim of the current study is to evaluate long-term efficacy of allograft usage in SCR through patient reported clinical outcomes. Methods: A retrospective review of patients undergoing SCR with use of dermal allografts from 2015 to 2021 was performed. Exclusion criteria included patients lost to follow up, revision or removal of graft, and inadequate follow up timepoints. Demographics and operative characteristics were collected. To evaluate efficacy of graft, numerical rating scale (NRS), American Shoulder and Elbow Score (ASES) were assessed postoperatively. Shoulder range of motion (ROM) was also evaluated by the 6-month postoperative timepoint. Improvement in NRS, ASES, and shoulder ROM from baseline values were evaluated using a t-test. Results: The final cohort was 21 patients with two patients undergoing revision and removal of the graft. Mean follow up time was 36.9 months. No major postoperative complications were recorded. Mean preoperative NRS and ASES score was 5.7 and 38.4, which both significantly improved postoperatively (p < 0.001). Patients demonstrated improvements in forward flexion, abduction in 90° rotation, and external and internal rotation. Conclusion: Use of acellular dermal grafts in SCR procedures for irreparable rotator cuff tears remains a viable long-term solution to restore shoulder function.

Anterior Cervical Discectomy and Fusion Results in Clinically Significant Improvements in Patients With Preoperative Sleep Difficulties.

BACKGROUND: Individual items within the Patient Health Questionnaire-9 (PHQ-9) have not been assessed as predictors of postoperative outcomes. Our objective is to study the relationship between responses to individual PHQ-9 items and achievement of a minimum clinically important difference (MCID) following anterior cervical discectomy and fusion (ACDF). METHODS: A prospective surgical database was reviewed for primary, single-level ACDF procedures performed for degenerative spinal pathology. Patient demographics, preoperative spinal pathology, and perioperative characteristics were recorded. Patient-reported outcome measures (PROMs) including PHQ-9, visual analog scale (VAS) neck and arm, Neck Disability Index, 12-item Short Form physical component score (SF-12 PCS), and Patient-Reported Outcomes Measurement Information System Physical Function were administered at preoperative and 6-week, 12-week, 6-month, 1-year, and 2-year postoperative timepoints. MCID achievement was determined by comparing postoperative PROM improvement from baseline to previously established values. Logistic regression assessed responses to each individual question of the preoperative PHQ-9 as predictors of MCID achievement in each other PROMs. RESULTS: Sixty-six ACDF patients were included with a mean age of 47.2 years. Herniated nucleus pulposus was the most common preoperative spinal diagnosis (95.6%). The mean operative duration was 50.3 minutes, the mean estimated blood loss was 27.5 mL, and most patients were discharged on postoperative day 0 (81.8%). A majority of patients achieved MCID for all measures except SF-12 PCS. PHQ-9 question 3 significantly predicted MCID achievement for VAS neck (P = 0.045), VAS arm (P = 0.049), and SF-12 PCS (P = 0.037). No other PHQ-9 items or overall PHQ-9 scores significantly predicted MCID achievement. CONCLUSION: Question 3 of the PHQ-9 regarding "trouble falling asleep, staying asleep, or sleeping too much" significantly predicted clinically meaningful improvement in neck pain, arm pain, and physical function following ACDF, although overall PHQ-9 scores did not. Providers should inform patients experiencing significant sleep-related difficulties that they may be especially likely to benefit from ACDF surgery. CLINICAL RELEVANCE: Evaluation of sleep from the PHQ-9 predicts clinically relevant improvement in neck pain, arm pain, and physical function in patients undergoing ACDF.