The story of dexamethasone and how it became one of the most widely used drugs in neurosurgery

Dexamethasone, a long-acting potent glucocorticoid, is one of the most widely used medications in neurosurgery. In this paper, the authors recount the history of dexamethasone's rise in neurosurgery and discuss its use in brain tumors in the context of emerging neuro-oncological immunotherapies. In 1958, Glen E. Arth synthesized a 16-alpha-methylated analog of cortisone (dexamethasone) for treatment of rheumatoid arthritis. Joseph Galicich, a neurosurgery resident at the time, applied the rheumatological drug to neurosurgery. He gave doses to patients who had undergone craniotomy for tumor removal and saw their paresis improve, midline shift resolve, and mortality rates decrease. He advocated for clinical trials and the drug became a mainstay in neurosurgery. As neuro-oncological treatments evolve to include immunotherapy, the immunosuppressive effects of dexamethasone are becoming an unwanted effect. The question then becomes: how does one treat the patient's symptoms if the only drug that has been used throughout history may become a detriment to their oncological treatment? Since its discovery, dexamethasone has maintained an impressive staying power in the field, acting as a standard drug for cerebral edema for more than 60 years. However, with the advent of immunotherapy, research is warranted to evaluate ways of treating symptomatic edema in the context of modern neuro-oncological therapies.

Distinctive Characteristics of Thoracolumbar Junction Region Stenosis

STUDY DESIGN

Retrospective case series and systemic literature meta-analysis.

BACKGROUND

Thoracolumbar junction region stenosis produces spinal cord compression just above the conus and may manifest with symptoms that are not typical of either thoracic myelopathy or neurogenic claudication from lumbar stenosis.

OBJECTIVE

As few studies describe its specific pattern of presenting symptoms and neurological deficits, this investigation was designed to improve understanding of this pathology.

METHODS

A retrospective review assessed surgically treated cases of T10-L1 degenerative stenosis. Clinical outcomes were evaluated with the thoracic Japanese Orthopedic Association score. In addition, a systematic review and meta-analysis was performed in accordance with guidelines provided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

RESULTS

Of 1069 patients undergoing laminectomy at 1477 levels, 31 patients (16M/15F) were treated at T10-L1 a mean age 64.4 (SD=11.8). Patients complained of lower extremity numbness in 29/31 (94%), urinary dysfunction 11/31 (35%), and back pain 11/31 (35%). All complained about gait difficulty and objective motor deficits were detected in 24 of 31 (77%). Weakness was most often seen in foot dorsiflexion 22/31 (71%). Deep tendon reflexes were increased in 10 (32%), decreased in 11 (35%), and normal 10 (32%); the Babinski sign was present 8/31 (26%). Mean thoracic Japanese Orthopedic Association scores improved from 6.4 (SD=1.8) to 8.4 (SD=1.8) ( P <0.00001). Gait subjectively improved in 27/31 (87%) numbness improved in 26/30 (87%); but urinary function improved in only 4/11 (45%).

CONCLUSIONS

Thoracolumbar junction stenosis produces distinctive neurological findings characterized by lower extremity numbness, weakness particularly in foot dorsiflexion, urinary dysfunction, and inconsistent reflex changes, a neurological pattern stemming from epiconus level compression and the myelomeres for the L5 roots. Surgery results in significant clinical improvement, with numbness and gait improving more than urinary dysfunction. Many patients with thoracolumbar junction stenosis are initially misdiagnosed as being symptomatic from lumbar stenosis, thus delaying definitive surgery.

High-Volume Centers Provide Superior Value of Care in the Surgical Treatment of Malignant Brain Tumor

BACKGROUND

Improved outcomes in surgical patients have been associated with increasing volume of cases. This has led to the development of centers that facilitate care for a specific patient population. This study aimed to evaluate associations of outcomes with hospital characteristics in patients undergoing resection of malignant brain tumors.

METHODS

The 2016-2020 National Inpatient Sample was queried for patients undergoing resection of malignant brain tumors. Teaching hospitals with caseloads >2 standard deviations above the mean (140 cases) were categorized as high-volume centers (HVCs). Value of care was evaluated by adding one point for each of the following: short length of stay, low total charges, favorable discharge disposition, and lack of major comorbidity or complication.

RESULTS

In 3009 hospitals, 118,390 patients underwent resection of malignant brain tumors. HVC criteria were met by 91 (3%) hospitals. HVCs were more likely to treat patients of younger age or higher socioeconomic status (P < 0.01 for all). The Mid-Atlantic and South Atlantic regions had the highest percentage of cases and number of HVCs. Value of care was higher at HVCs (P < 0.01). Care at HVCs was associated with decreased complications (P < 0.01 for all) and improved patient outcomes (P < 0.01 for all).

CONCLUSIONS

Patients undergoing craniotomy for malignant brain neoplasms have superior outcomes in HVCs. Trends of centralization may reflect the benefits of multidisciplinary treatment, geographic preferences, publicity, and cultural impact. Improvement of access to care is an important consideration as this trend continues.

Discrete Mechanistic Target of Rapamycin Signaling Pathways, Stem Cells, and Therapeutic Targets

The mechanistic target of rapamycin (mTOR) is a serine/threonine kinase that functions via its discrete binding partners to form two multiprotein complexes, mTOR complex 1 and 2 (mTORC1 and mTORC2). Rapamycin-sensitive mTORC1, which regulates protein synthesis and cell growth, is tightly controlled by PI3K/Akt and is nutrient-/growth factor-sensitive. In the brain, mTORC1 is also sensitive to neurotransmitter signaling. mTORC2, which is modulated by growth factor signaling, is associated with ribosomes and is insensitive to rapamycin. mTOR regulates stem cell and cancer stem cell characteristics. Aberrant Akt/mTOR activation is involved in multistep tumorigenesis in a variety of cancers, thereby suggesting that the inhibition of mTOR may have therapeutic potential. Rapamycin and its analogues, known as rapalogues, suppress mTOR activity through an allosteric mechanism that only suppresses mTORC1, albeit incompletely. ATP-catalytic binding site inhibitors are designed to inhibit both complexes. This review describes the regulation of mTOR and the targeting of its complexes in the treatment of cancers, such as glioblastoma, and their stem cells.

Patterns for Child Protective Service Referrals in a Pediatric Burn Cohort

BACKGROUND

Pediatric non-accidental trauma often necessitates the involvement of protective services. However, the subjectivity and lack of standardization of referral infrastructure may result in some discrepancies between referral patterns and instances of child abuse.

METHODS

An institutional retrospective chart review was conducted between 2015 and 2021, in which all cases of patients under the age of 14 who suffered a burn injury and received a child protective service (CPS) consult were reviewed. Baseline demographics and characteristics were defined. Multivariate analysis was utilized to identify predictors of CPS involvement, while the regression analysis was employed to parse associations between burn injuries and CPS involvement.

RESULTS

Between July 2015 and December 2021, 340 patients (median age two years, IQR: 1-6 years) under the age of 14 who experienced a burn injury were evaluated. Forty-four (12.9%) of the patients' cases received a CPS referral, of which three (0.9%) resulted in a CPS intervention. The most common mechanism of burn within the cohort was scald (241 patients, 70.9%). The median total body surface area (TBSA) was 3.0% (IQR: 1.0%-6.0%), and 76 (22.4%) suffered a high TBSA (>75th percentile). Caucasian race (p < 0.001) and scald mechanisms (p = 0.014) were associated with higher TBSA. When considering how such injuries translated to CPS referrals, increasing age was found to be associated with a decreased likelihood of CPS involvement. Meanwhile, the Black race (p = 0.027) and increasing area deprivation index (ADI) (p = 0.038) were associated with CPS involvement. Those with CPS involvement experienced a greater length of hospital stay (p = 0.001). Black race and intensive care unit level of care were found to be positive predictors of CPS involvement. In total, three (6.82%) of the 44 cases with CPS involvement were found to be substantiated. The three children who required CPS intervention were discharged to foster care settings.

CONCLUSION

Hospitalized pediatric burn injuries must be investigated due to concern of child abuse, yet external factors such as race and socioeconomic status may play a role in the involvement of CPS. Such referrals may not always be substantiated and could lead to further injurious sequelae for children and their families.

Brain Metastases Are Regulated by Immuno-inflammatory Signaling Pathways Governed by STAT3, MAPK and Tumor Suppressor p53 Status: Possible Therapeutic Targets

BACKGROUND/AIM

Brain metastasis (BM) is a complex multi-step process involving various immune checkpoint proteins. Mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinases 1/2 (ERK1/2), and signal transducer and activator of transcription 3 (STAT3) are implicated in tumorigenesis and are critical upstream regulators of Programmed Death Ligand 1 (PD-L1), an immunotherapy target. Tumor suppressor p53, dysregulated in cancers, regulates STAT3 and ERK1/2 signaling. This study examined the roles of STAT3, MAPK and p53 status in BM initiation and maintenance.

MATERIALS AND METHODS

Twenty-six BM, with various primary malignancies, were used (IRB-approved) to determine mutant p53 (p53mt), pSTAT3Tyr705, pERK1/2Thr202/Tyr204, and PD-L1 expression using immunohistochemistry. cDNA microarray was used for gene expression analysis. Brain-metastatic breast cancer cells (MDA-MB-231) were treated with STAT3 (NSC74859) or MAPK/ERK1/2 (U0126) inhibitors in regular or astrocytic media. ERK1/2 pathway was assessed using western blotting, and cell proliferation and migration were determined using MTT and scratch-wound assays, respectively.

RESULTS

pSTAT3Tyr705 and pERK1/2Thr202/Tyr204 were expressed at tumor margins, whereas p53mt and PD-L1 were uniformly expressed, with significant overlap between expression of these proteins. Gene expression analysis identified alterations in 18 p53- and 32 STAT3- or MAPK-associated genes contributing to dysregulated immune responses and cell cycle regulation. U0126 and NSC74859 reduced pERK1/2Thr202/Tyr204 expression. Cell proliferation decreased following each treatment (p≤0.01). Migration stagnated following U0126 treatment in astrocytic media (p≤0.01).

CONCLUSION

Activation of STAT3 and ERK1/2 promotes BM and provides compelling evidence for use of STAT3, ERK1/2 and p53 status as potential immunotherapeutic targets in BM.

Early tracheostomy in patients undergoing mechanical thrombectomy for acute ischemic stroke

PURPOSE

Respiratory failure following mechanical thrombectomy (MT) for acute ischemic stroke (AIS) is a known complication, and requirement of tracheostomy is associated with worse outcomes. Our objective is to evaluate characteristics associated with tracheostomy timing in AIS patients treated with MT.

METHODS

The National Inpatient Sample was queried for adult patients treated with MT for AIS from 2016 to 2019. Baseline demographic characteristics, comorbidities, and inpatient outcomes were analyzed for associations in patients who received tracheostomy. Timing of early tracheostomy (ETR) was defined as placement before day 8 of hospital stay.

RESULTS

Of 3505 AIS-MT patients who received tracheostomy, 915 (26.1%) underwent ETR. Patients who underwent ETR had shorter length of stay (LOS) (25.39 days vs 32.43 days, p < 0.001) and lower total hospital charges ($483,472.07 vs $612,362.86, p < 0.001). ETR did not confer a mortality benefit but was associated with less acute kidney injury (OR, 0.697; p = 0.013), pneumonia (OR, 0.449; p < 0.001), and sepsis (OR, 0.536; p = 0.002).

CONCLUSION

An expected increase in complications and healthcare resource utilization is seen in AIS-MT patients receiving tracheostomy, likely reflecting the severity of patients' post-stroke neurologic injury. Among these high-risk patients, ETR was predictive of shorter LOS and fewer complications.

Independent predictors of systemic inflammatory response syndrome for intramedullary nailing of femoral shaft fractures: Analysis of national inpatient sample database

Background

The systemic inflammatory response syndrome (SIRS) is a clinical reaction that can occur due to a variety of stimuli. Reamed intramedullary femoral nailing is a common orthopedic surgery that has been shown to induce SIRS. To date, no nationwide analyses have been performed to evaluate the incidence, risk factors, and economic burdens of SIRS following intramedullary femoral nailing for femoral shaft fractures. The objective of this study is to investigate the independent predictors, incidence, post-operative, and economic burden of SIRS among patients treated with intramedullary nailing for femoral shaft fractures.

Methods

We utilized the 2016-2019 National Inpatient Sample (NIS) to identify patients who underwent intramedullary femoral nailing and were diagnosed with non-infectious SIRS (NI-SIRS) based on ICD-10-CM coding. Identified patients who underwent intramedullary femoral nailing were dichotomized into SIRS and Non-SIRS groups to assess independent predictors of SIRS development, and to compare post-operative complications and costs.

Results

A total of 65,240 patients with femur shaft fractures underwent IMFN, of which 665 (1.0 %) developed NI-SIRS. Patients with NI-SIRS had a higher incidence of laparotomy (OR = 13.97, p < 0.001), initial treatment with external fixation (OR = 1.845, p < 0.001), and late application of external fixation (OR = 4.884, p = 0.005). Routine discharge (OR = 0.491, p < 0.001) was less likely in patients with NI-SIRS. Length of stay (12.38 days vs 7.16 days, p < 0.001) and total charges ($278, 590 vs $145,118, p < 0.001) were both increased in patients with NI-SIRS.

Conclusion

NI-SIRS is associated with increasing injury severity and post-operative complications. Those that developed NI-SIRS experienced higher healthcare resource utilization. Risk factors associated with development of NI-SIRS warrant further investigation.

High area deprivation index is associated with increased injury severity in pediatric burn patients

BACKGROUND

Burn injuries play a significant role in pediatric injury-related mortality and morbidity. In this study, we aim to explore the relationship between patient demographics, socioeconomic factos and burn severity in pediatric patients.

METHODS

Patients under age 14 hospitalized at Westchester Medical Center for burn injury between 2015 and 2021 were reviewed. Demographic variables including mechanism of burn, total body surface area (TBSA) involvement, surgical intervention, hospital length of stay (LOS), and LOS per TBSA burn were extracted. The Area Deprivation Index (ADI) was calculated to further assess socioeconomic factors.

RESULTS

We included 399 patients under the age of 14 hospitalized for burn injuries at our institution between 2015 and 2021. The median age was 2 (IQR 1-6) years old, and 42.6% were female. High ADI (p = 0.018), Caucasian race (p = 0.001), and flame mechanism (p < 0.001) were independently associated with burn TBSA> 5%. LOS per TBSA was shorter in the Caucasian population (p = 0.022).

CONCLUSION

In burn injury patients, further research is necessary to investigate modifiable risk factors in individuals of Caucasian race or lower socioeconomic status to target effective prevention campaigns.

Intramedullary Spinal Hemorrhage in Behcet's Syndrome: A Case Report and Systematic Review

Acute neurological manifestations in patients with Behcet's syndrome are rare yet may lead to devastating outcomes. Distinguishing primary neurological deficits from spontaneous hemorrhagic insults is of particular importance for the prognosis of patients with Behcet's syndrome. Here, we investigate the clinical characteristics, management, and outcomes of nontraumatic hemorrhagic injury in patients with Bechet's syndrome. Following the case presentation, a systematic review of the literature identified cases of spontaneous hemorrhage among patients with Behcet's syndrome. Variables of interest were collected from each article to characterize patient demographics, clinical manifestations, management, and reported outcomes. Additionally, a rare case of nontraumatic intramedullary spinal bleeding in a young male with Behcet's syndrome is presented. Including our case, we analyzed 12 cases of spontaneous bleeding associated with Behcet's syndrome in 12 articles. Patient age ranged from 16 to 71 (median = 36), with a male predominance (n = 11, 91.7%). Involvement of cardiothoracic structures (n = 3, 25%), pulmonary (n = 4, 33.3%), and gastrointestinal or genitourinary vasculature (n = 3, 25%) was most common, followed by extracranial (n = 2, 16.7%) and central nervous system vasculature (n = 1, 8.3%). Clinical presentation varied depending on which specific systems or anatomical structures were involved. Anticoagulation or antiplatelet therapy was mentioned in three cases (27.3%). Erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) were noted to be elevated in six cases (54.5%). Most cases were managed surgically (n = 8, 66.7%); four cases were managed conservatively (33.3%). In our case, the patient's intramedullary bleed was allowed to dissolve without further manipulation. Of the reported outcomes, major recovery was achieved in 10 patients (83.3%), and two patients died from aneurysm or pseudoaneurysm rupture (16.7%). New-onset neurological findings in patients with Behcet's syndrome should raise suspicion for possible spontaneous hemorrhage. Our case presents the first reported instance of an abrupt onset of neurological injury secondary to intramedullary spinal cord bleed in Behcet's syndrome. A systematic review of the literature demonstrates no difference in mortality for patients managed conservatively compared to those who undergo surgical treatment.

Superior discrimination of the Risk Analysis Index compared with the 5-item modified frailty index in 30-day outcome prediction after anterior cervical discectomy and fusion

OBJECTIVE

The objective of this paper was to compare the predictive ability of the recalibrated Risk Analysis Index (RAI-rev) with the 5-item modified frailty index-5 (mFI-5) for postoperative outcomes of anterior cervical discectomy and fusion (ACDF).

METHODS

This study was performed using data of adult (age > 18 years) ACDF patients obtained from the National Surgical Quality Improvement Program database during the years 2015-2019. Multivariate modeling and receiver operating characteristic (ROC) curve analysis, including area under the curve/C-statistic calculation with the DeLong test, were performed to evaluate the comparative discriminative ability of the RAI-rev and mFI-5 for 5 postoperative outcomes.

RESULTS

Both the RAI-rev and mFI-5 were independent predictors of increased postoperative mortality and morbidity in a cohort of 61,441 ACDF patients. In the ROC analysis for 30-day mortality prediction, C-statistics indicated a significantly better performance of the RAI-rev (C-statistic = 0.855, 95% CI 0.852-0.858) compared with the mFI-5 (C-statistic = 0.684, 95% CI 0.680-0.688) (p < 0.001, DeLong test). The results were similar for postoperative ACDF morbidity, Clavien-Dindo grade IV complications, nonhome discharge, and reoperation, demonstrating the superior discriminative ability of the RAI-rev compared with the mFI-5.

CONCLUSIONS

The RAI-rev demonstrates superior discrimination to the mFI-5 in predicting postoperative ACDF mortality and morbidity. To the authors' knowledge, this is the first study to document frailty as an independent risk factor for postoperative mortality after ACDF. The RAI-rev has conceptual fidelity to the frailty phenotype and may be more useful than the mFI-5 in preoperative ACDF risk stratification. Prospective validation of these findings is necessary, but patients with high RAI-rev scores may benefit from knowing that they might have an increased surgical risk for ACDF morbidity and mortality.

Thecal sac ligation in the setting of thoracic spondyloptosis with complete cord transection

Background

Traumatic spondyloptosis (TS) with complete spinal cord transection and unrepairable durotomy is particularly rare and can lead to a difficult-to-manage cerebrospinal fluid (CSF) leak.

Methods

We performed a systematic review of the literature on TS and discuss the management strategies and outcomes of TS with cord transection and significant dural tear. We also report a novel case of a 26-year-old female who presented with thoracic TS with complete spinal cord transection and unrepairable durotomy with high-flow CSF leak.

Results

Of 93 articles that resulted in the search query, 13 described cases of TS with complete cord transection. The approach to dural repair was only described in 8 (n = 20) of the 13 articles. The dura was not repaired in two (20%) of the cases. Ligation of the proximal end of the dural defect was done in 15 (75%) of the cases, all at the same institution. One (5%) case report describes ligation of the distal end; one (5%) case describes the repair of the dura with duraplasty; and another (5%) case describes repair using muscle graft to partially reconstruct the defect.

Conclusion

Suture ligation of the thecal sac in the setting of traumatic complete spinal cord transection with significant dural disruption has been described in the international literature and is a safe and successful technique to prevent complications associated with persisting high-flow CSF leakage. To the best of our knowledge, this is the first report of thecal sac ligation of the proximal end of the defect from the United States.

Dural Closure Techniques and Cerebrospinal Fluid Leak Incidence After Resection of Primary Intradural Spinal Tumors: A Systematic Review

STUDY DESIGN

This is a systematic review of primary intradural spinal tumors (PIDSTs) and the frequency of postoperative cerebrospinal fluid (CSF) leaks.

OBJECTIVE

This study aimed to compare CSF leak rates among techniques for dural watertight closure (WTC) after the resection of PIDSTs.

SUMMARY OF BACKGROUND DATA

Resection of PIDSTs may result in persistent CSF leak. This complication is associated with infection, wound dehiscence, increased length of stay, and morbidity. Dural closure techniques have been developed to decrease the CSF leak rate.

METHODS

A PubMed search was performed in 2022 with these inclusion criteria: written in English, describe PIDST patients, specify the method of dural closure, report rates of CSF leak, and be published between 2015 and 2020. Articles were excluded if they had <5 patients. We used standardized toolkits to assess the risk of bias. We assessed patient baseline characteristics, tumor pathology, CSF leak rate, and dural closure techniques; analysis of variance and a 1-way Fisher exact test were used.

RESULTS

A total of 4 studies (201 patients) satisfied the inclusion criteria. One study utilized artificial dura (AD) and fibrin glue to perform WTC and CSF diversion, with lumbar drainage as needed. The rate of CSF leak was different among the 4 studies (P=0.017). The study using AD with dural closure adjunct (DCA) for WTC was associated with higher CSF leak rates than those using native dura (ND) with DCA. There was no difference in CSF leak rate between ND-WTC and AD-DCA, or with any of the ND-DCA studies.

CONCLUSIONS

After resection of PIDSTs, the use of autologous fat grafts with ND resulted in lower rates of CSF leak, while use of fibrin glue and AD resulted in the highest rates. These characteristics suggest that a component of hydrophobic scaffolding may be required for WTC. A limitation included articles with low levels of evidence. Continued investigation to understand mechanisms for WTC is warranted.

LEVEL OF EVIDENCE

Level 3.

Adult Trauma Patients With Thoracolumbar Injury Classification and Severity Score of 4: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVE

Evaluate characteristics of patients with thoracolumbar injury classification and severity (TLICS) score of 4 (To4) severity traumatic thoracolumbar injury.

SUMMARY OF BACKGROUND DATA

The TLICS score is used to predict the need for operative versus nonoperative management in adult patients with traumatic thoracolumbar injury. Ambiguity exists in its application and score categorization.

METHODS

A systematic review of the literature was performed. The databases of MEDLINE, Embase, Web of Science, and Cochrane Review were queried. Studies included adults with traumatic thoracolumbar injury with assigned TLICS score and description of management strategy.

RESULTS

A total of 16 studies met inclusion criteria representing 1911 adult patients with traumatic thoracolumbar injury. There were 503 (26.32%) patients with To4, of which 298 (59.24%) were operative. Studies focusing on the thoracolumbar junction and AO Type A fracture morphology had To4 patient incidences of 11.15% and 52.94%, respectively. Multiple studies describe better quality of life, pain scores, and radiographic outcomes in To4 who underwent operative treatment patients.

CONCLUSION

To4 injuries are more commonly AO Type A and located in the thoracolumbar junction in adult patients with traumatic thoracolumbar injury. Despite ambiguous recommendations regarding treatment provided by TLICS, outcomes favor operative intervention in this subset of traumatic thoracolumbar injury patients.

A double-hit: End-stage renal disease patients suffer worse outcomes in intracerebral hemorrhage

BACKGROUND

Intracerebral hemorrhage (ICH) carries significant morbidity and mortality. Previous single-center retrospective analysis suggests that end-stage renal disease (ESRD) is a risk factor for severe ICH and worse outcomes. This investigation aims to examine the impact of ESRD on ICH severity, complications, and outcomes using a multicenter national database.

METHODS

The International Classification of Disease, Ninth and Tenth Revision Clinical Modification codes were used to query the National Inpatient Sample for patients with ICH and ESRD between 2010 and 2019. Primary endpoints were the functional outcome, length of stay (LOS), and in-hospital mortality. Multivariate variable regression models and a propensity-score matched analysis were established to analyze patient outcomes associated with baseline patient characteristics.

RESULTS

We identified 211,266 patients with ICH, and among them, 7,864 (3.77%) patients had a concurrent diagnosis of ESRD. Patients with ESRD were younger (60.85 vs. 67.64, P < 0.01) and demonstrated increased ICH severity (0.78 vs. 0.77, P < 0.01). ESRD patients experienced higher rates of sepsis (15.9% vs. 6.15%, P < 0.01), acute myocardial infarction (8.05% vs. 3.65%, P < 0.01), and cardiac arrest (5.94% vs. 2.4%, P < 0.01). In addition, ESRD predicted poor discharge disposition (odds ratio [OR]: 2.385, 95% confidence interval [CI]: 2.227-2.555, P < 0.01), longer hospital LOS (OR: 1.629, 95% CI: 1.553-1.709, P < 0.01), and in-hospital mortality (OR: 2.786, 95% CI: 2.647-2.932, P < 0.01).

CONCLUSIONS

This study utilizes a multicenter database to analyze the effect of ESRD on ICH outcomes. ESRD is a significant predictor of poor functional outcomes, in-hospital mortality, and prolonged stay in the ICH population.

Incidence, Characteristics, and Outcomes of Stroke in Pediatric Patients with Celiac Disease

(1) Background: Celiac disease (CD) can cause long-term inflammation and endothelial dysfunction and has been cited as a risk factor for acute ischemic stroke (AIS) in pediatric patients. However, the rate and outcomes of AIS in pediatric patients with CD has not been explored in a large population. Our objective is to explore the rate, severity, and outcomes of CD amongst pediatric AIS patients on a nationwide level. (2) Methods: The National Inpatient Sample (NIS) database was queried from 2016 to 2020 for pediatric patients with a principal diagnosis of AIS. Patients with a concurrent diagnosis of CD (AIS-CD) were compared to those without (AIS). Baseline demographics and comorbidities, clinical variables of severity, hospital complications, and the rates of tissue plasminogen activator (tPA) and mechanical thrombectomy were compared between the two groups. The main outcomes studied were mortality, discharge disposition, length of stay (LOS), and total hospital charges. (3) Results: Of 12,755 pediatric patients with a principal diagnosis of AIS, 75 (0.6%) had concurrent CD. There were no differences in the severity, discharge disposition, or mortality between the AIS-CD and AIS patients. Patients with AIS-CD were more likely to receive tPA at an outside hospital within 24 h of admission (p < 0.01) and more likely to undergo mechanical thrombectomy (p < 0.01) compared to the AIS patients. (4) Conclusions: CD patients made up only 0.6% of all pediatric AIS patients. No differences in the severity, mortality, or discharge disposition suggests a minimal to absent role of CD in the etiology of stroke. The CD-AIS patients were more likely to receive a tPA or undergo a mechanical thrombectomy; studies are needed to confirm the safety and efficacy of these interventions in pediatric patients.

Disparities in anterior cervical discectomy and fusion provision and outcomes for cervical stenosis

Background

Disparities in neurosurgical care have emerged as an area of interest when considering the impact of social determinants on access to health care. Decompression via anterior cervical discectomy and fusion (ACDF) for cervical stenosis (CS) may prevent progression towards debilitating complications that may severely compromise one's quality of life. This retrospective database analysis aims to elucidate demographic and socioeconomic trends in ACDF provision and outcomes of CS-related pathologies.

Methods

The Healthcare Cost and Utilization Project National Inpatient Sample database was queried between 2016 and 2019 using International Classification of Diseases 10th edition codes for patients undergoing ACDF as a treatment for spinal cord and nerve root compression. Baseline demographics and inpatient stay measures were analyzed.

Results

Patients of White race were significantly less likely to present with manifestations of CS such as myelopathy, plegia, and bowel-bladder dysfunction. Meanwhile, Black patients and Hispanic patients were significantly more likely to experience these impairments representative of the more severe stages of the degenerative spine disease process. White race conferred a lesser risk of complications such as tracheostomy, pneumonia, and acute kidney injury in comparison to non-white race. Insurance by Medicaid and Medicare conferred significant risks in terms of more advanced disease prior to intervention and negative inpatient. Patients in the highest quartile of median income consistently fared better than patients in the lowest quartile across almost every aspect ranging from degree of progression at initial presentation to incidence of complications to healthcare resource utilization. All outcomes for patients age > 65 were worse than patients who were younger at the time of the intervention.

Conclusions

Significant disparities exist in the trajectory of CS and the risks associated with ACDF amongst various demographic cohorts. The differences between patient populations may be reflective of a larger additive burden for certain populations, especially when considering patients' intersectionality.

Safety of vagus nerve stimulation and responsive neurostimulation used in combination for multifocal and generalized onset epilepsy in pediatric patients

OBJECTIVE

The aim of this study was to assess the safety and efficacy of combined active responsive neurostimulation (RNS) and vagus nerve stimulation (VNS) therapies in pediatric patients with drug-resistant epilepsy.

METHODS

A single-center retrospective chart review was conducted on pediatric patients implanted with the RNS System with a concomitant active VNS System (VNS+RNS) between 2015 and 2021. Patients with at least 1 month of overlapping concomitant VNS and RNS treatment were included. Patients who had an RNS device implanted after 21 years of age, those who had responsive neurostimulators implanted after their VNS was inactivated, or those in whom the VNS battery died and was not replaced before RNS System implantation were excluded.

RESULTS

Seven pediatric VNS+RNS patients were identified, and their courses of treatment were evaluated. All patients tolerated concurrent VNS and RNS treatment well, no device-device interactions were identified, and no major treatment-related adverse effects were noted. The median follow-up after RNS System implantation was 1.2 years. By electroclinical criteria, all 7 patients achieved 75%-99% reductions in the frequency of disabling seizures after RNS System implantation. By patient and caregiver report, 2 patients (28.6%) had 75%-99% reductions in the frequency of their disabling seizures, 2 patients (28.6%) achieved 50%-74% reductions, 2 patients achieved 1%-24% reduction in frequency of disabling seizures, and 1 patient (14.3%) experienced a 1%-24% increase in seizure frequency. The available VNS magnet swipe data identified 2 patients with 75%-99% reductions in seizure frequency as measured by magnet swipes, one with 25%-49% reductions and the other with 1%-24% increases in seizure frequency as measured by magnet swipes.

CONCLUSIONS

This study demonstrated that RNS and VNS therapies can safely be used simultaneously in pediatric patients. RNS may potentially augment the therapeutic effects of VNS treatment. Patients in whom a response to VNS has been suboptimal should still be considered for RNS therapy.

Upregulated Expression of the IL-9 Receptor on TRAF3-Deficient B Lymphocytes Confers Ig Isotype Switching Responsiveness to IL-9 in the Presence of Antigen Receptor Engagement and IL-4

The pleiotropic cytokine IL-9 signals to target cells by binding to a heterodimeric receptor consisting of the unique subunit IL-9R and the common subunit γ-chain shared by multiple cytokines of the γ-chain family. In the current study, we found that the expression of IL-9R was strikingly upregulated in mouse naive follicular B cells genetically deficient in TNFR-associated factor 3 (TRAF3), a critical regulator of B cell survival and function. The highly upregulated IL-9R on Traf3-/- follicular B cells conferred responsiveness to IL-9, including IgM production and STAT3 phosphorylation. Interestingly, IL-9 significantly enhanced class switch recombination to IgG1 induced by BCR crosslinking plus IL-4 in Traf3-/- B cells, which was not observed in littermate control B cells. We further demonstrated that blocking the JAK-STAT3 signaling pathway abrogated the enhancing effect of IL-9 on class switch recombination to IgG1 induced by BCR crosslinking plus IL-4 in Traf3-/- B cells. Our study thus revealed, to our knowledge, a novel pathway that TRAF3 suppresses B cell activation and Ig isotype switching by inhibiting IL-9R-JAK-STAT3 signaling. Taken together, our findings provide (to our knowledge) new insights into the TRAF3-IL-9R axis in B cell function and have significant implications for the understanding and treatment of a variety of human diseases involving aberrant B cell activation such as autoimmune disorders.

Risk factors for posttraumatic hydrocephalus after decompressive hemicraniectomy in pediatric patients with traumatic brain injury

OBJECTIVE

Traumatic brain injuries (TBIs) play a significant role in pediatric mortality and morbidity. Decompressive hemicraniectomy (DHC) is a treatment option for severe pediatric TBI (pTBI) not amenable to medical management of intracranial pressure. Posttraumatic hydrocephalus (PTH) is a known sequela of DHC that may lead to further injury and decreased capacity for recovery if not identified and treated. The goal of this study was to characterize risk factors for PTH after DHC in patients with pTBI by using the Kids' Inpatient Database (KID).

METHODS

The records collected in the KID from 2016 to 2019 were queried for patients with TBI using International Classification of Diseases, 10th Revision codes. Data defining demographics, complications, procedures, and outcomes were extracted. Multivariate regression was used to identify risk factors associated with PTH. The authors also investigated length of stay and hospital charges.

RESULTS

Of 68,793 patients with pTBI, 848 (1.2%) patients underwent DHC. Prolonged mechanical ventilation (PMV) was required in 475 (56.0%) patients with pTBI undergoing DHC. Three hundred (35.4%) patients received an external ventricular drain (EVD) prior to DHC. PTH was seen in 105 (12.4%), and 50 (5.9%) received a ventriculoperitoneal shunt. DHC before hospital day 2 was negatively associated with PTH (OR 0.464, 95% CI 0.267-0.804; p = 0.006), whereas PMV (OR 2.204, 95% CI 1.344-3.615; p = 0.002) and EVD placement prior to DHC (OR 6.362, 95% CI 3.667-11.037; p < 0.001) were positively associated with PTH. PMV (OR 7.919, 95% CI 2.793-22.454; p < 0.001), TBI with subdural hematoma (OR 2.606, 95% CI 1.119-6.072; p = 0.026), and EVD placement prior to DHC (OR 4.575, 95% CI 2.253-9.291; p < 0.001) were independent predictors of ventriculoperitoneal shunt insertion. The mean length of stay and total hospital charges were significantly increased in patients with PMV and in those with PTH.

CONCLUSIONS

PMV, presence of subdural hematoma, and EVD placement prior to DHC are risk factors for PTH in patients with pTBI who underwent DHC. Higher healthcare resource utilization was seen in patients with PTH. Identifying risk factors for PTH may improve early diagnosis and efficient resource utilization.

Frailty and outcomes in lacunar stroke

BACKGROUND

Lacunar strokes (LS) are ischemic strokes of the small perforating arteries of deep gray and white matter of the brain. Frailty has been associated with greater mortality and attenuated response to treatment after stroke. However, the effect of frailty on patients with LS has not been previously described.

OBJECTIVE

To analyze the association between frailty and outcomes in LS.

METHODS

Patients with LS were selected from the National Inpatient Sample (NIS) 2016-2019 using the International Classification of Disease, 10^th edition (ICD-10) diagnosis codes. The 11-point modified frailty scale (mFI-11) was used to group patients into severely frail and non-severely frail cohorts. Demographics, clinical characteristics, and complications were defined. Health care resource utilization (HRU) was evaluated by comparing total hospital charges and length of stay (LOS). Other outcomes studied were discharge disposition and inpatient death.

RESULTS

Of 48,980 patients with LS, 10,830 (22.1%) were severely frail. Severely frail patients were more likely to be older, have comorbidities, and pertain to lower socioeconomic status categories. Severely frail patients with LS had worse clinical stroke severity and increased rates of complications such as urinary tract infection (UTI) and pneumonia (PNA). Additionally, severe frailty was associated with unfavorable outcomes and increased HRU.

CONCLUSION

Severe frailty in LS patients is associated with higher rates of complications and increased HRU. Risk stratification based on frailty may allow for individualized treatments to help mitigate adverse outcomes in the setting of LS.

Effect of tracheostomy timing in pediatric patients with traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) is a prevalent cause of disability and death in the pediatric population, often requiring prolonged mechanical ventilation. Patients with significant TBI or intracranial hemorrhage require advanced airway management to protect against aspiration, hypoxia, and hypercarbia, eventually necessitating tracheostomy. While tracheostomy is much less common in children compared to adults, its prevalence among pediatric populations has been steadily increasing. Although early tracheostomy has demonstrated improved outcomes in adult patients, optimal tracheostomy timing in the pediatric population with TBI remains to be definitively established.

OBJECTIVE

This retrospective cohort analysis aims to evaluate pediatric TBI patients who undergo tracheostomy and to investigate the impact of tracheostomy timing on outcomes.

DESIGN/METHODS

The Healthcare Cost and Utilization Project (HCUP) Kids' Inpatient Database (KID), collected between in 2016 and 2019, was queried using International Classification of Disease 10th edition (ICD10) codes for patients with traumatic brain injury who had received a tracheostomy. Baseline demographics, insurance status, and procedural day data were analyzed with univariate and multivariate regression analyses. Propensity score matching was performed to estimate the incidence of medical complications and mortality related to early versus late tracheostomy timing (as defined by median = 9 days).

RESULTS

Of the 68,793 patients (mean age = 14, IQR 4-18) who suffered a TBI, 1,956 (2.8%) received a tracheostomy during their hospital stay. TBI patients who were tracheostomized were older (mean age = 16.5 vs 11.4 years), more likely to have injuries classified as severe TBIs and more likely to have accumulated more than one indicator of parenchymal injury as measured by the Composite Stroke Severity Scale (CSSS >1) than non-tracheostomized TBI patients. TBI patients with a tracheostomy were more likely to encounter serious complications such as sepsis, acute kidney injury (AKI), meningitis, or acute respiratory distress syndrome (ARDS). They were also more likely to necessitate an external ventricular drain (EVD) or decompressive hemicraniectomy (DHC) than TBI patients without a tracheostomy. Tracheostomy was also negatively associated with routine discharge. Procedural timing was assessed in 1,867 patients; older children (age >15 years) were more likely to undergo earlier placements (p < 0.001). Propensity score matching (PSM) comparing early versus late placement was completed by controlling for age, gender, and TBI severity. Those who were subjected to late tracheostomy (>9 days) were more likely to face complications such as AKI or deep vein thrombosis (DVT) as well as a host of respiratory conditions such as pulmonary embolism, aspiration pneumonitis, pneumonia, or ARDS. While the timing did not significantly impact mortality across the PSM cohorts, late tracheostomy was associated with increased length of stay (LOS) and ventilator dependence.

CONCLUSIONS

Tracheostomy, while necessary for some patients who have sustained a TBI, is itself associated with several risks that should be assessed in context of each individual patient's overall condition. Additionally, the timing of the intervention may significantly impact the trajectory of the patient's recovery. Early intervention may reduce the incidence of serious complications as well as length of stay and dependence on a ventilator and facilitate a timelier recovery.

Characteristics of Patients Selected for Surgical Treatment of Spinal Meningioma

BACKGROUND

Spinal meningiomas are benign extra-axial tumors that can present with neurological deficits. Treatment partly depends on the degree of disability as there is no agreed-upon patient selection algorithm at present. We aimed to elucidate general patient selection patterns in patients undergoing surgery for spinal meningioma.

METHODS

Data for patients with spinal tumors admitted between 2016 and 2019 were extracted from the U.S. Nationwide Inpatient Sample. We identified patients with a primary diagnosis of spinal meningioma (using International Classification of Disease, 10^th revision codes) and divided them into surgical and nonsurgical treatment groups. Patient characteristics were evaluated for intergroup differences.

RESULTS

Of 6395 patients with spinal meningioma, 5845 (91.4%) underwent surgery. Advanced age, nonwhite race, obesity, diabetes mellitus, chronic renal failure, and anticoagulant/antiplatelet use were less prevalent in the surgical group (all P < 0.001). The only positive predictor of surgical treatment was elective admission status (odds ratio, 3.166; P < 0.001); negative predictors were low income, Medicaid insurance, anxiety, obesity, and plegia. Patients with bowel-bladder dysfunction, plegia, or radiculopathy were less likely to undergo surgical treatment. The surgery group was less likely to experience certain complications (deep vein thrombosis, P < 0.001; pulmonary embolism, P = 0.002). Increased total hospital charges were associated with nonwhite race, diabetes, depression, obesity, myelopathy, plegia, and surgery.

CONCLUSIONS

Patients treated surgically had a decreased incidence of complications, comorbidities, and Medicaid payer status. A pattern of increased utilization of health care resources and spending was also observed in the surgery group. The results indicate a potentially underserved population of patients with spinal meningioma.

Cervical fusion for adult patients with atlantoaxial rotatory subluxation

BACKGROUND

Atlantoaxial rotatory subluxation (AARS) is a rare injury of the C1/C2 junction. It is often associated with trauma in adults. Treatment may depend on the duration of symptoms and clinical presentation, but there is no consensus regarding the ideal management of these injuries. Our objective is to ascertain the prevalence of neurological deficit, complications, and outcomes of patients diagnosed with AARS undergoing cervical fusion (CF) versus those treated without CF.

METHODS

The 2016-2019 National Inpatient Sample (NIS) was queried using International Classification of Diseases, 10th revision (ICD-10) for adult patients with C1/C2 subluxation. Patients undergoing CF were defined through ICD-10 procedure codes. Baseline health and acute illness severity was calculated using the 11-point modified frailty index (mFI-11). Presenting characteristics, treatment complications, and outcomes were evaluated of CF vs. non-CF patients.

RESULTS

Of 990 adult patients with AARS, 720 were treated without CF and 270 were treated with CF. CF patients were more often myelopathic. Patients that had undergone CF treatment were negatively associated with having had extensive trauma. Patients undergoing CF experienced significantly longer length of stay (LOS), increased healthcare resource utilization, and decreased inpatient mortality. Sepsis had a negative association with patients that underwent CF treatment while pneumonia had a positive association.

CONCLUSIONS

Adult patients undergoing CF for AARS demonstrated an increase in healthcare resource utilization but also a significant decrease in mortality. Extent of acute injury appears to have a strong influence on decision making for CF. Further study of decision making for treatment of this rare injury in adults is warranted.

Intraoperative navigation in surgical management of traumatic spine injury: a propensity score matching analysis

BACKGROUND

Traumatic spinal injury (TSI) can lead to severe morbidity and significant health care resource utilization. Intraoperative navigation (ION) systems have been shown to improve outcomes in some populations. However, controversy about the benefit of ION remains. To our knowledge, there is no large database analysis studying the outcomes of ION on TSI patients. Here we hope to compare complications and outcomes in patients with TSI undergoing spinal fusion of 3 or more levels with or without the use of ION.

METHODS

The 2015-2019 National Surgical Quality Improvement Program (NSQIP) database was queried for cases of posterior spinal instrumentation of 3 or more levels. This population was then selected for postoperative diagnosis consistent with TSI. The effect of prolonged operative time was analyzed for all patients. Propensity score matching analysis was performed to create ION case and non-ION control groups. Baseline demographic characteristics, complications, and outcome data were collected and compared between ION and non-ION groups.

RESULTS

A total of 1,034 patients were included in the propensity matched analysis. Among comorbidities, only obesity was significantly more likely in the non-ION group. There was no difference in case complexity between the two groups. ION was associated with higher incidence of prolonged operative time but was a negative independent predictor for sepsis. Prolonged operative time was a significant independent predictor for pulmonary embolism and requirement of transfusion in all patients. Discharge to home, readmission, and reoperation rates did not differ between TSI patients with or without ION.

CONCLUSIONS

Use of ION during posterior spinal fusion of 3 or more levels in TSI patients is not associated with worse outcomes. Prolonged operative time, rather than ION, appears to have a higher influence on the rate of complications in this population. Evaluation of ION in the context of specific populations and pathology is warranted to optimize its use.

Frailty is a risk factor for intracranial abscess and is associated with longer length of stay: a retrospective single institution case-control study

BACKGROUND

Intracranial abscess (IA) causes significant morbidity and mortality. The impact of baseline frailty status on post-operative outcomes of IA patients remains largely unknown. The present study evaluated if frailty status can be used to prognosticate outcomes in IA patients.

METHODS

We retrospectively reviewed all IA patients undergoing craniotomy at our institution from 2011 to 2018 (n =18). These IA patients were age and gender matched with patients undergoing craniotomy for intracranial tumor (IT), an internal control for comparison. Demographic and clinical data were collected to measure frailty, using the modified frailty index-11 (mFI-11), pre-operative American Society of Anesthesiologists Physical Status Classification System (ASA), and study their association with post-operative complications, as measured by the Clavien-Dindo Grade (CDG).

RESULTS

No significant difference in mFI-11 or ASA score was observed between the IA and IT groups (p = 0.058 and p = 0.131, respectively). IA patients had significantly higher CDG as compared with the control IT patients (p < 0.001). There was a trend towards increasing LOS in the IA group as compared to the IT group (p = 0.053). Increasing mFI and ASA were significant predictors of LOS by multiple linear regression in the IA group (p = 0.006 and p = 0.001, respectively), but not in the control IT group. Neither mFI-11 nor ASA were found to be predictors for CDG in either group. Within this case-control group of patients, we found an increase for odds of having IA with increasing mFI (OR 1.838, CI 95% 1.016-3.362, p = 0.044).

CONCLUSIONS

Frail IA patients tend to have more severe postoperative complications. The mFI-11 seems to predict increased resource utilization in the form of LOS. This study provides the initial retrospective data of another neurosurgical pathology where frailty leads to significantly worse outcomes. We also found that mFI may serve as a potential risk factor for severe disease.

Responsive Neurostimulation Targeting the Anterior, Centromedian and Pulvinar Thalamic Nuclei and the Detection of Electrographic Seizures in Pediatric and Young Adult Patients

Background

Responsive neurostimulation (RNS System) has been utilized as a treatment for intractable epilepsy. The RNS System delivers stimulation in response to detected abnormal activity, via leads covering the seizure foci, in response to detections of predefined epileptiform activity with the goal of decreasing seizure frequency and severity. While thalamic leads are often implanted in combination with cortical strip leads, implantation and stimulation with bilateral thalamic leads alone is less common, and the ability to detect electrographic seizures using RNS System thalamic leads is uncertain.

Objective

The present study retrospectively evaluated fourteen patients with RNS System depth leads implanted in the thalamus, with or without concomitant implantation of cortical strip leads, to determine the ability to detect electrographic seizures in the thalamus. Detailed patient presentations and lead trajectories were reviewed alongside electroencephalographic (ECoG) analyses.

Results

Anterior nucleus thalamic (ANT) leads, whether bilateral or unilateral and combined with a cortical strip lead, successfully detected and terminated epileptiform activity, as demonstrated by Cases 2 and 3. Similarly, bilateral centromedian thalamic (CMT) leads or a combination of one centromedian thalamic alongside a cortical strip lead also demonstrated the ability to detect electrographic seizures as seen in Cases 6 and 9. Bilateral pulvinar leads likewise produced reliable seizure detection in Patient 14. Detections of electrographic seizures in thalamic nuclei did not appear to be affected by whether the patient was pediatric or adult at the time of RNS System implantation. Sole thalamic leads paralleled the combination of thalamic and cortical strip leads in terms of preventing the propagation of electrographic seizures.

Conclusion

Thalamic nuclei present a promising target for detection and stimulation via the RNS System for seizures with multifocal or generalized onsets. These areas provide a modifiable, reversible therapeutic option for patients who are not candidates for surgical resection or ablation.

Correction of Sagittal Balance With Resection of Kissing Spines

Kissing spines syndrome, also known as Baastrup’s disease, is a common yet underdiagnosed disorder involving close approximation of adjacent spinous processes. These painful pseudoarticulations may be secondary to the compensatory mechanisms that result from sagittal imbalance. Conventional operative correction of sagittal balance includes a wide range of procedures from facetectomies to vertebral column resection. Resection of kissing spines for the operative management of sagittal imbalance is a treatment modality not extensively discussed in the literature but may offer improved patient outcomes with shorter operative times, lower risk, and reduced length of stay.

A 67-year old male with a history of degenerative disk disease and scoliosis presented with neurogenic claudication and severe back pain that worsened with walking and improved with sitting. X-ray imaging of the lumbar spine revealed straightening of the normal lumbar lordotic curvature with mild rotoscoliosis. There was also evidence of retrolisthesis of L2 on L3 that worsened with flexion. The patient had Baastrup’s disease at the L3-4 and L4, 5 levels that contributed to his reduced range of motion on extension imaging. Operative treatments including long-segment fusion with interbody cages to correct sagittal balance were considered with a discussion of possible debilitating and high-risk post-surgical outcomes. Instead, the patient underwent a simple decompression surgery involving laminectomies and resection of kissing spines to correct his sagittal imbalance. Postoperative follow-up imaging demonstrated significant improvement in sagittal balance, and the patient expressed relief of back and leg pain.

Although underdiagnosed, consideration of kissing spines syndrome in the surgical correction of sagittal imbalance may offer an improvement over conventional operations. Our case presents a unique surgical perspective on the treatment of spinal stenosis with kissing spines with particular regard to correcting the sagittal imbalance, avoiding debilitating procedures, and providing better immediate postoperative outcomes.

Multifaceted Immunomodulatory Effects of the BTK Inhibitors Ibrutinib and Acalabrutinib on Different Immune Cell Subsets - Beyond B Lymphocytes

The clinical success of the two BTK inhibitors, ibrutinib and acalabrutinib, represents a major breakthrough in the treatment of chronic lymphocytic leukemia (CLL) and has also revolutionized the treatment options for other B cell malignancies. Increasing evidence indicates that in addition to their direct effects on B lymphocytes, both BTK inhibitors also directly impact the homeostasis, phenotype and function of many other cell subsets of the immune system, which contribute to their high efficacy as well as adverse effects observed in CLL patients. In this review, we attempt to provide an overview on the overlapping and differential effects of ibrutinib and acalabrutinib on specific receptor signaling pathways in different immune cell subsets other than B cells, including T cells, NK cells, monocytes, macrophages, granulocytes, myeloid-derived suppressor cells, dendritic cells, osteoclasts, mast cells and platelets. The shared and distinct effects of ibrutinib versus acalabrutinib are mediated through BTK-dependent and BTK-independent mechanisms, respectively. Such immunomodulatory effects of the two drugs have fueled myriad explorations of their repurposing opportunities for the treatment of a wide variety of other human diseases involving immune dysregulation.