Alzheimer's disease marker phospho-tau181 is not elevated in the first year after moderate-to-severe TBI

BACKGROUND: Traumatic brain injury (TBI) is associated with the tauopathies Alzheimer's disease and chronic traumatic encephalopathy. Advanced immunoassays show significant elevations in plasma total tau (t-tau) early post-TBI, but concentrations subsequently normalise rapidly. Tau phosphorylated at serine-181 (p-tau181) is a well-validated Alzheimer's disease marker that could potentially seed progressive neurodegeneration. We tested whether post-traumatic p-tau181 concentrations are elevated and relate to progressive brain atrophy. METHODS: Plasma p-tau181 and other post-traumatic biomarkers, including total-tau (t-tau), neurofilament light (NfL), ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) and glial fibrillary acidic protein (GFAP), were assessed after moderate-to-severe TBI in the BIO-AX-TBI cohort (first sample mean 2.7 days, second sample within 10 days, then 6 weeks, 6 months and 12 months, n=42). Brain atrophy rates were assessed in aligned serial MRI (n=40). Concentrations were compared patients with and without Alzheimer's disease, with healthy controls. RESULTS: Plasma p-tau181 concentrations were significantly raised in patients with Alzheimer's disease but not after TBI, where concentrations were non-elevated, and remained stable over one year. P-tau181 after TBI was not predictive of brain atrophy rates in either grey or white matter. In contrast, substantial trauma-associated elevations in t-tau, NfL, GFAP and UCH-L1 were seen, with concentrations of NfL and t-tau predictive of brain atrophy rates. CONCLUSIONS: Plasma p-tau181 is not significantly elevated during the first year after moderate-to-severe TBI and levels do not relate to neuroimaging measures of neurodegeneration

Transarterial embolization of the external carotid artery in the treatment of life-threatening haemorrhage following blunt maxillofacial trauma

Severe bleeding after blunt maxillofacial trauma is a rare but life-threatening event. Non-responders to conventional treatment options with surgically inaccessible bleeding points can be treated by transarterial embolization (TAE) of the external carotid artery (ECA) or its branches. Case series on such embolizations are small; considering the relatively high incidence of maxillofacial trauma, the ECA TAE procedure has been hypothesized either underused or underreported. In addition, the literature on the ECA TAE using novel non-adhesive liquid embolization agents is remarkably scarce

Huge variation in obtaining ethical permission for a non-interventional observational study in Europe

BACKGROUND: Ethical approval (EA) must be obtained before medical research can start. We describe the differences in EA for an pseudonymous, non-interventional, observational European study. METHODS: Sixteen European national coordinators (NCs) of the international study on very old intensive care patients answered an online questionnaire concerning their experience getting EA. RESULTS: N = 8/16 of the NCs could apply at one single national ethical committee (EC), while the others had to apply to various regional ECs and/or individual hospital institutional research boards (IRBs). The time between applying for EA and the first decision varied between 7 days and 300 days. In 9/16 informed consent from the patient was not deemed necessary; in 7/16 informed consent was required from the patient or relatives. The upload of coded data to a central database required additional information in 14/16. In 4/16 the NCs had to ask separate approval to keep a subject identification code list to de-pseudonymize the patients if questions would occur. Only 2/16 of the NCs agreed that informed consent was necessary for this observational study. Overall, 6/16 of the NCs were satisfied with the entire process and 8/16 were (very) unsatisfied. 11/16 would welcome a European central EC that would judge observational studies for all European countries. DISCUSSION: Variations in the process and prolonged time needed to get EA for observational studies hampers inclusion of patients in some European countries. This might have a negative influence on the external validity. Further harmonization of ethical approval process across Europe is welcomed for low-risk observational studies. CONCLUSION: Getting ethical approval for low-risk, non-interventional, observational studies varies enormously across European countries

Huge variation in obtaining ethical permission for a non-interventional observational study in Europe

BACKGROUND: Ethical approval (EA) must be obtained before medical research can start. We describe the differences in EA for an pseudonymous, non-interventional, observational European study. METHODS: Sixteen European national coordinators (NCs) of the international study on very old intensive care patients answered an online questionnaire concerning their experience getting EA. RESULTS: N = 8/16 of the NCs could apply at one single national ethical committee (EC), while the others had to apply to various regional ECs and/or individual hospital institutional research boards (IRBs). The time between applying for EA and the first decision varied between 7 days and 300 days. In 9/16 informed consent from the patient was not deemed necessary; in 7/16 informed consent was required from the patient or relatives. The upload of coded data to a central database required additional information in 14/16. In 4/16 the NCs had to ask separate approval to keep a subject identification code list to de-pseudonymize the patients if questions would occur. Only 2/16 of the NCs agreed that informed consent was necessary for this observational study. Overall, 6/16 of the NCs were satisfied with the entire process and 8/16 were (very) unsatisfied. 11/16 would welcome a European central EC that would judge observational studies for all European countries. DISCUSSION: Variations in the process and prolonged time needed to get EA for observational studies hampers inclusion of patients in some European countries. This might have a negative influence on the external validity. Further harmonization of ethical approval process across Europe is welcomed for low-risk observational studies. CONCLUSION: Getting ethical approval for low-risk, non-interventional, observational studies varies enormously across European countries

Axonal marker neurofilament light predicts long-term outcomes and progressive neurodegeneration after traumatic brain injury

Axonal injury is a key determinant of long-term outcomes after traumatic brain injury (TBI) but has been difficult to measure clinically. Fluid biomarker assays can now sensitively quantify neuronal proteins in blood. Axonal components such as neurofilament light (NfL) potentially provide a diagnostic measure of injury. In the multicenter BIO-AX-TBI study of moderate-severe TBI, we investigated relationships between fluid biomarkers, advanced neuroimaging, and clinical outcomes. Cerebral microdialysis was used to assess biomarker concentrations in brain extracellular fluid aligned with plasma measurement. An experimental injury model was used to validate biomarkers against histopathology. Plasma NfL increased after TBI, peaking at 10 days to 6 weeks but remaining abnormal at 1 year. Concentrations were around 10 times higher early after TBI than in controls (patients with extracranial injuries). NfL concentrations correlated with diffusion MRI measures of axonal injury and predicted white matter neurodegeneration. Plasma TAU predicted early gray matter atrophy. NfL was the strongest predictor of functional outcomes at 1 year. Cerebral microdialysis showed that NfL concentrations in plasma and brain extracellular fluid were highly correlated. An experimental injury model confirmed a dose-response relationship of histopathologically defined axonal injury to plasma NfL. In conclusion, plasma NfL provides a sensitive and clinically meaningful measure of axonal injury produced by TBI. This reflects the extent of underlying damage, validated using advanced MRI, cerebral microdialysis, and an experimental model. The results support the incorporation of NfL sampling subacutely after injury into clinical practice to assist with the diagnosis of axonal injury and to improve prognostication.</p

Traumatic brain injury : integrated approaches to improve prevention, clinical care, and research

Rahul Raj on työryhmän InTBIR Participants Investigators jäsen.Peer reviewe

Treatments for intracranial hypertension in acute brain-injured patients: grading, timing, and association with outcome. Data from the SYNAPSE-ICU study

Purpose: Uncertainties remain about the safety and efficacy of therapies for managing intracranial hypertension in acute brain injured (ABI) patients. This study aims to describe the therapeutical approaches used in ABI, with/without intracranial pressure (ICP) monitoring, among different pathologies and across different countries, and their association with six&nbsp;months mortality and neurological outcome. Methods: A preplanned subanalysis of the SYNAPSE-ICU study, a multicentre, prospective, international, observational cohort study, describing the ICP treatment, graded according to Therapy Intensity Level (TIL) scale, in patients with ABI during the first week of intensive care unit (ICU) admission. Results: 2320 patients were included in the analysis. The median age was 55 (I-III quartiles = 39-69) years, and 800 (34.5%) were female. During the first week from ICU admission, no-basic TIL was used in 382 (16.5%) patients, mild-moderate in 1643 (70.8%), and extreme in 295 cases (eTIL, 12.7%). Patients who received eTIL were younger (median age 49 (I-III quartiles = 35-62) vs 56 (40-69) years, p &lt; 0.001), with less cardiovascular pre-injury comorbidities (859 (44%) vs 90 (31.4%), p &lt; 0.001), with more episodes of neuroworsening (160 (56.1%) vs 653 (33.3%), p &lt; 0.001), and were more frequently monitored with an ICP device (221 (74.9%) vs 1037 (51.2%), p &lt; 0.001). Considerable variability in the frequency of use and type of eTIL adopted was observed between centres and countries. At six&nbsp;months, patients who received no-basic TIL had an increased risk of mortality (Hazard ratio, HR = 1.612, 95% Confidence Interval, CI = 1.243-2.091, p &lt; 0.001) compared to patients who received eTIL. No difference was observed when comparing mild-moderate TIL with eTIL (HR = 1.017, 95% CI = 0.823-1.257, p = 0.873). No significant association between the use of TIL and neurological outcome was observed. Conclusions: During the first week of ICU admission, therapies to control high ICP are frequently used, especially mild-moderate TIL. In selected patients, the use of aggressive strategies can have a beneficial effect on six&nbsp;months mortality but not on neurological outcome