Longitudinal Recovery Following Repetitive Traumatic Brain Injury

Importance

One traumatic brain injury (TBI) increases the risk of subsequent TBIs. Research on longitudinal outcomes of civilian repetitive TBIs is limited.

Objective

To investigate associations between sustaining 1 or more TBIs (ie, postindex TBIs) after study enrollment (ie, index TBIs) and multidimensional outcomes at 1 year and 3 to 7 years.

Design, Setting, and Participants

This cohort study included participants presenting to emergency departments enrolled within 24 hours of TBI in the prospective, 18-center Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study (enrollment years, February 2014 to July 2020). Participants who completed outcome assessments at 1 year and 3 to 7 years were included. Data were analyzed from September 2022 to August 2023.

Exposures

Postindex TBI(s).

Main Outcomes and Measures

Demographic and clinical factors, prior TBI (ie, preindex TBI), and functional (Glasgow Outcome Scale-Extended [GOSE]), postconcussive (Rivermead Post-Concussion Symptoms Questionnaire [RPQ]), psychological distress (Brief Symptom Inventory-18 [BSI-18]), depressive (Patient Health Questionnaire-9 [PHQ-9]), posttraumatic stress disorder (PTSD; PTSD Checklist for DSM-5 [PCL-5]), and health-related quality-of-life (Quality of Life After Brain Injury-Overall Scale [QOLIBRI-OS]) outcomes were assessed. Adjusted mean differences (aMDs) and adjusted relative risks are reported with 95% CIs.

Results

Of 2417 TRACK-TBI participants, 1572 completed the outcomes assessment at 1 year (1049 [66.7%] male; mean [SD] age, 41.6 [17.5] years) and 1084 completed the outcomes assessment at 3 to 7 years (714 [65.9%] male; mean [SD] age, 40.6 [17.0] years). At 1 year, a total of 60 participants (4%) were Asian, 255 (16%) were Black, 1213 (77%) were White, 39 (2%) were another race, and 5 (0.3%) had unknown race. At 3 to 7 years, 39 (4%) were Asian, 149 (14%) were Black, 868 (80%) were White, 26 (2%) had another race, and 2 (0.2%) had unknown race. A total of 50 (3.2%) and 132 (12.2%) reported 1 or more postindex TBIs at 1 year and 3 to 7 years, respectively. Risk factors for postindex TBI were psychiatric history, preindex TBI, and extracranial injury severity. At 1 year, compared with those without postindex TBI, participants with postindex TBI had worse functional recovery (GOSE score of 8: adjusted relative risk, 0.57; 95% CI, 0.34-0.96) and health-related quality of life (QOLIBRI-OS: aMD, -15.9; 95% CI, -22.6 to -9.1), and greater postconcussive symptoms (RPQ: aMD, 8.1; 95% CI, 4.2-11.9), psychological distress symptoms (BSI-18: aMD, 5.3; 95% CI, 2.1-8.6), depression symptoms (PHQ-9: aMD, 3.0; 95% CI, 1.5-4.4), and PTSD symptoms (PCL-5: aMD, 7.8; 95% CI, 3.2-12.4). At 3 to 7 years, these associations remained statistically significant. Multiple (2 or more) postindex TBIs were associated with poorer outcomes across all domains.

Conclusions and Relevance

In this cohort study of patients with acute TBI, postindex TBI was associated with worse symptomatology across outcome domains at 1 year and 3 to 7 years postinjury, and there was a dose-dependent response with multiple postindex TBIs. These results underscore the critical need to provide TBI prevention, education, counseling, and follow-up care to at-risk patients.

Socioeconomic and clinical factors associated with prolonged hospital length of stay after traumatic brain injury

BACKGROUND

Hospital length of stay (HLOS) after traumatic brain injury (TBI) is a metric of injury severity, resource utilization, and access to services. This study aimed to evaluate socioeconomic and clinical factors associated with prolonged HLOS after TBI.

METHODS

Retrospective data from adult hospitalized patients diagnosed with acute TBI at a US Level 1 trauma center between August 1, 2019 - April 1, 2022 were extracted from the electronic health record. HLOS was stratified by Tier (1: 1-74th percentile; 2: 75-84th; 3: 85-94th; 4: 95-99th). Demographic, socioeconomic, injury severity, and level-of-care factors were compared by HLOS. Multivariable logistic regressions evaluated associations between socioeconomic and clinical variables and prolonged HLOS, using multivariable odds ratios (mOR) and [95% confidence intervals]. Estimated daily charges were calculated for a subset of medically-stable inpatients awaiting placement. Statistical significance was assessed at p < 0.05.

RESULTS

In 1443 patients, median HLOS was 4 days (interquartile range 2-8; range 0-145). HLOS Tiers were 0-7, 8-13, 14-27, and ≥28 days (Tiers 1-4, respectively). Patients with Tier 4 HLOS differed significantly from others, with increased Medicaid insurance (53.4% vs. 30.3-33.1%, p = 0.003), severe TBI (Glasgow Coma Scale 3-8: 38.4% vs. 8.7-18.2%, p < 0.001), younger age (mean 52.3-years vs. 61.1-63.7-years, p = 0.003), low socioeconomic status (53.4% vs. 32.0-33.9%, p = 0.003), and need for post-acute care (60.3% vs. 11.2-39.7%, p < 0.001). Independent factors associated with prolonged (Tier 4) HLOS were Medicaid (mOR = 1.99 [1.08-3.68], vs. Medicare/commercial), moderate and severe TBI (mOR = 3.48 [1.61-7.56]; mOR = 4.43 [2.18-8.99], respectively, vs. mild TBI), and need for post-acute placement (mOR = 10.68 [5.74-19.89], while age was protective (per-year mOR = 0.98 [0.97-0.99]). Estimated daily charges for a medically-stable inpatient was $17126.

CONCLUSIONS

Medicaid insurance, moderate/severe TBI, and need for post-acute care were independently associated with prolonged HLOS ≥28 days. Medically-stable inpatients awaiting placement accrue immense daily healthcare costs. At-risk patients should be identified early, receive care transitions resources, and be prioritized for discharge coordination pathways.

Analysis of Current Neurological Surgery Residents and Prior Medical Education: Do Medical School Attributes Matter?

BACKGROUND

With the recent changes to the U.S. Medical Licensing Examination grading system, an understanding of the factors that influence the neurological surgery residency match process is crucial for residency directors. The aim of the present retrospective study was to explore the associations of medical school location, ranking, private school status, size, and presence of an American Association of Neurological Surgeons (AANS) chapter or neurological surgery interest group (NSIG) with the neurosurgery match outcomes.

METHODS

An enrollment list of all accredited U.S. neurosurgery residency programs was compiled on June 28, 2021. For the included residents, the residency program, degree, and previously attended medical school were retrieved. The geographic location, ranking, private school status, and size were collected for the residency programs and medical schools attended by the residents at each program.

RESULTS

A total of 1437 residents from 101 neurosurgery residency programs (89%) were included. Graduates from the top 25 medical schools were more likely to match into their home residency programs (P < 0.001) and highly ranked residency programs (P < 0.001). Students from larger medical schools were also more likely to match into larger (P < 0.001) and highly ranked (P < 0.001) programs than were applicants from smaller schools. Students from medical schools with an AANS chapter or NSIG were also more likely to match into top ranked programs (P < 0.001 for both).

CONCLUSIONS

Medical students from the top 25 medical schools, private medical schools, medical schools with an AANS chapter, and medical schools with an NSIG were more likely to match into a prestigious residency program. These findings suggest that underlying biases might be present for program directors to consider in the resident selection process.

Brown tumor of the iliac crest initially misdiagnosed as a giant cell tumor of the bone

SUMMARY

Brown tumors (BTs) are expansile osteolytic lesions complicating severe primary hyperparathyroidism (PHPT). Clinical, radiological and histological features of BTs share many similarities with other giant cell-containing lesions of the bone, which can make their diagnosis challenging. We report the case of a 32-year-old man in whom an aggressive osteolytic lesion of the iliac crest was initially diagnosed as a giant cell tumor by biopsy. The patient was scheduled for surgical curettage, with a course of neoadjuvant denosumab. Routine biochemical workup prior to denosumab administration incidentally revealed high serum calcium levels. The patient was diagnosed with PHPT and a parathyroid adenoma was identified. In light of these findings, histological slices of the iliac lesion were reviewed and diagnosis of a BT was confirmed. Follow-up CT-scans performed 2 and 7 months after parathyroidectomy showed regression and re-ossification of the bone lesion. The aim of this case report is to underline the importance of distinguishing BTs from other giant cell-containing lesions of the bone and to highlight the relevance of measuring serum calcium as part of the initial evaluation of osteolytic bone lesions. This can have a major impact on patients' management and can prevent unnecessary invasive surgical interventions.

LEARNING POINTS

Although rare, brown tumors should always be considered in the differential diagnosis of osteolytic giant cell-containing bone lesions. Among giant cell-containing lesions of the bone, the main differential diagnoses of brown tumors are giant cell tumors and aneurysmal bone cysts. Clinical, radiological and histological characteristics can be non-discriminating between brown tumors and giant cell tumors. One of the best ways to distinguish these two diagnoses appears to be through biochemical workup. Differentiating brown tumors from giant cell tumors and aneurysmal bone cysts is crucial in order to ensure better patient care and prevent unnecessary morbid surgical interventions.

Investigating the Effect of Air Cavities of Sinuses on the Radiotherapy Dose Distribution Using Monte Carlo Method

BACKGROUND

Considering that some vital organs exist in the head and neck region, the treatment of tumors in this area is a crucial task. The existence of air cavities, namely sinuses, disrupt the radiotherapy dose distribution. The study aims to analyze the effect of maxillary, frontal, ethmoid and sphenoid sinuses on radiotherapy dose distribution by Monte Carlo method.

MATERIAL AND METHODS

In order to analyze the effect of the cavities on dose distribution, the maxillary, frontal, ethmoid and sphenoid sinus cavities were simulated with (3×3.2×2) cm³, (2×2×3.2) cm³, (1×1×1.2) cm³ and (1×1×2) cm³ dimensions.

RESULTS

In the analysis of the dose distribution caused by cavities, some parameters were observed, including: inhomogeneity of dose distribution in the cavities, inhomogeneity of dose on the edges of the air cavities and dispersion of the radiations after the air cavity. The amount of the dose in various situations showed differences: before the cavity a 0.64% and a 2.76% decrease, a 12.06% and a 17.17% decrease in the air zone, and a 2.25% and a 5.9% increase after the cavity.

CONCLUSION

The results indicate that a drop in dose before the air cavities and in the air zone occurs due to the lack of scattered radiation. Furthermore, the rise in dose was due to the passage of more radiation from the air cavity and dose deposition after the air cavity. The changes in dose distribution are dependent on the cavity size and depth. As a result, this has to be noted in the treatment planning and MU calculations of the patient.

Examining health care spending trends over a decade: the Palestinian case

An analysis was made of recent health care spending patterns in the occupied Palestinian territory, in order to inform future health policy-making and planning. Data were obtained from the national health accounts for the period 2000-2011. The current level of resource allocation to the health care sector is higher than in many developed countries and is not sustainable. The private sector represents the largest source of health financing (61%) and the burden falls disproportionally on individual households, who account for 63% of private health care expenditure. Key recommendations include: building capacity in the government sector to reduce the outsourcing of health services; modifying inequitable financing mechanisms to reduce the burden on households; and allocating more resources for health promotion and disease prevention programmes. Reorientation of the health system is also needed in terms of reducing the share of spending on inpatient services in favour of more day surgery, outpatient and home-based services.

Epileptiform synchronization and high-frequency oscillations in brain slices comprising piriform and entorhinal cortices

We employed field potential recordings in extended in vitro brain slices form Sprague-Dawley rats containing the piriform and entorhinal cortices (PC and EC, respectively) to identify the characteristics of epileptiform discharges and concomitant high-frequency oscillations (HFOs, ripples: 80-200Hz, fast ripples: 250-500Hz) during bath application of 4-aminopyridine (4AP, 50μM). Ictal-like discharges occurred in PC and EC either synchronously or independently of each other; synchronous ictal discharges always emerged from a synchronous "fast" interictal background whereas asynchronous ictal discharges were preceded by a "slow" interictal event. In addition, asynchronous ictal discharges had longer duration and interval of occurrence than synchronous ictal discharges, and contained a higher proportion of ripples and fast ripples. Cutting the connections between PC and EC made synchronicity disappear and increased ictal discharges duration in the EC but failed in changing HFO occurrence in both areas. Finally, antagonizing ionotropic glutamatergic receptors abolished ictal activity in all experiments, increased the duration and rate of occurrence of interictal discharges occurring in PC-EC interconnected slices while it did not influence the slow asynchronous interictal discharges in both areas. Our results identify some novel in vitro interactions between olfactory (PC) and limbic (EC) structures that presumably contribute to in vivo ictogenesis as well.

Insulin resistance is an independent correlate of increased urine albumin excretion: a cross-sectional study in Iranian Type 2 diabetic patients

AIMS

To assess the association of insulin resistance with increased urinary albumin excretion (UAE) in a cohort of Iranian Type 2 diabetic patients.

METHODS

Three hundred and sixty-one men and 472 women with Type 2 diabetes were enrolled from three different outpatient clinics (Tehran, Iran) during the period 2005-2008. Patients with obstructive uropathy, severe heart failure, liver disease, cancer, autoimmune disease and macroalbuminuria were not included. Microalbuminuria (MA; defined as UAE >or= 30 mg/day) was found in 242 (29.1%) patients; 591 (70.9%) subjects had normoalbuminuria (UAE < 30 mg/day). Insulin resistance was assessed using homeostasis model assessment of insulin resistance (HOMA-IR).

RESULTS

HOMA-IR index values were higher in subjects with MA than those with normoalbuminuria (P < 0.00001). Adjusted values (for age, sex and duration of diabetes) of UAE and HOMA-IR were 11.81 +/- 7.51 (mg/day) and 3.30 +/- 2.21 in normoalbuminuric and 75.36 +/- 55.57 (mg/day) and 4.98 +/- 3.22 in the MA group, respectively (P < 0.00001 for all). Multiple regression analysis showed that UAE was predicted by HOMA-IR, independently of age, duration of diagnosed diabetes, triglycerides, waist circumference, metabolic control, blood pressure and related treatments (P < 0.00001). When patients were categorized into quartiles of HOMA-IR, those of the fourth quartile (i.e. the most insulin resistant) were at a higher risk of increased UAE than other quartiles [odds ratio (OR) 3.7 (95% confidence intervals 2.7-6.2)].

CONCLUSIONS

In Iranian Type 2 diabetic patients, albuminuria was strongly associated with insulin resistance. HOMA-IR is an independent predictor of UAE.

Analysis of neutron and gamma-ray streaming along the maze of NRCAM thallium production target room

Study of the shield performance of a thallium-203 production target room has been investigated in this work. Neutron and gamma-ray equivalent dose rates at various points of the maze are calculated by simulating the transport of streaming neutrons, and photons using Monte Carlo method. For determination of neutron and gamma-ray source intensities and their energy spectrum, we have applied SRIM 2003 and ALICE91 computer codes to Tl target and its Cu substrate for a 145 microA of 28.5 MeV protons beam. The MCNP/4C code has been applied with neutron source term in mode n p to consider both prompt neutrons and secondary gamma-rays. Then the code is applied for the prompt gamma-rays as the source term. The neutron-flux energy spectrum and equivalent dose rates for neutron and gamma-rays in various positions in the maze have been calculated. It has been found that the deviation between calculated and measured dose values along the maze is less than 20%.

Expression of alpha(v)beta6 integrin in oral leukoplakia

The distribution of alpha(v)beta6 integrin was examined in oral leukoplakia, lichen planus and squamous cell carcinomas using immunohistochemistry. Controls included oral mucosal wounds, chronically inflamed and normal oral mucosa. Integrins beta1, beta3, beta4, beta5, fibronectin and tenascin were also studied. The integrin alpha(v)beta6 was highly expressed throughout the whole lesion of 90% of the squamous cell carcinomas but was not present in any of the normal specimens. alpha(v)beta6 integrin was also expressed in 41% of the leukoplakia specimens, and 85% of the lichen planus samples, but in none of the tissues with inflammatory hyperplasia or chronic inflammation. The expression of beta1 integrins was localized in the basal layer, and that of the beta4 at the cell surface facing the basement membrane of all specimens. The integrins beta3 and beta5 were absent from all normal and leukoplakia specimens. Fibronectin and tenascin were present in the connective tissue underneath the epithelium of all the sections, and their expression was similar in both alpha(v)beta6-positive and alpha(v)beta6-negative tissues. A group of 28 leukoplakia patients were followed 1-4 years after first diagnosis. In this group, initially alpha(v)beta6 integrin-positive leukoplakia specimens had high tendency for disease progression while alpha(v)beta6-negative specimens did not progress. These results suggest that the expression of alpha(v)beta6 integrin could be associated in the malignant transformation of oral leukoplakias.

Laminin-5 expression is independent of the injury and the microenvironment during reepithelialization of wounds

We examined the expression of laminin-5 and its integrin receptors during reepithelialization of human wounds. We used suction blisters of skin as a model of keratinocyte migration on a basement membrane matrix and mucosal full-thickness wounds as a model in which keratinocytes migrate in a provisional matrix. An animal model, in which human epidermal keratinocytes were injected into the back of athymic mice, was used to follow the deposition of the basement membrane components. In 4-day-old blisters, about 20-50 cells at the leading edge of the migrating tongue showed cytoplasmic laminin-5 immunostaining. Laminin-5 mRNA was detected in 15-30 cells at the leading edge of the migrating epidermis. alpha3beta1 and alpha6beta4 integrins were found in membrane projections of the migrating basal cells and also in suprabasal cell layers, suggesting their combined role in binding laminin-5. In mucosal wounds, laminin-5 was the only basement membrane zone component that was deposited between the clot and the migrating keratinocytes. In the animal model, linear deposition of laminin-5 and alpha6beta4 integrin was already seen on Day 2, whereas the other basement membrane zone components were not yet organized. The results suggest that, regardless of the injury and the microenvironment, laminin-5 plays an essential role in the interaction between wound keratinocytes and the surrounding matrix.

Are serial Holter QT, late potential, and wavelet measurement clinically useful?

Clinical centers are increasingly using new techniques such as Holter QT, late potential, and wavelet measurements. However, we lack validated databases for the assessment of the performance of the signal-processing methods and their reproducibility. Failure of the QT interval to adapt to changes in the heart rate is considered to be a more meaningful parameter than QT prolongation itself. In this study, different factors that may affect the reproducibility of QT and QTm (onset of the QRS to the maximum of T) measurement are analyzed: the incidence of sympathetic tone and parasympathetic activity on low- and high-frequency QT variability, the very low frequency dependency of the QT interval to changes in the R-R interval, changes in the heart's position, and measurement errors. Typical root-mean-square values of the beat-to-beat measurement errors in upright-position Holter recordings are only 1.5 ms for QT versus 3.4 ms for QTm. Although the dependence of the QT interval on the heart rate is well established, the method for rate correction of the QT interval remains controversial. None of the formulas for heart rate adjustment of the QT previously proposed provide complete correction for all of the rate influences involved due to "memory phenomenon"; that is, there is a time delay, ranging up to 3-4 minutes, between a change in heart rate and the subsequent change in the QT interval. This problem has been solved by developing patient-specific neural networks that are trained to "identify" the dynamic behavior of the QT interval (or QTm) as a function of the R-R interval in order to predict the beat-to-beat changes of the QT interval as a function of the measured beat-to-beat changes of the R-R interval. Computing the differences between the predicted and the measured QT interval will allow for the detection of any significant deviations, both in the steady-state and transient conditions. Recent developments in the analysis of the high-resolution electrocardiogram (HRECG) in the time domain and frequency domain, with emphasis on the assessment of the reproducibility of late potential and wavelet measurements, are also reported in this study. The two main causes of variability in HRECG analysis are physiology and, for time-domain analysis, intermanufacturer variability. Physiologic changes can be overcome by standardizing the clinical protocols and repeating the recordings. The most important technical requirement for the proper use of late potentials is to standardize the algorithm for the detection of QRS offset among different late potential analyzing machines so that clinical data can be exchanged. The recently introduced wavelet transform provides a fruitful alternative to the more classical time-domain methods. Preliminary results show an 8 to 15% performance improvement over conventional time-domain analysis for the stratification of the HRECG after myocardial infarction. Reproducibility is excellent, up to 100%, but needs to be assessed on larger populations matched for age, sex, and pathology.