In-depth characterization of a long-term, resuscitated model of acute subdural hematoma-induced brain injury.

OBJECTIVE: Acute subdural hematoma (ASDH) is a leading entity in brain injury. Rodent models mostly lack standard intensive care, while large animal models frequently are only short term. Therefore, the authors developed a long-term, resuscitated porcine model of ASDH-induced brain injury and report their findings. METHODS: Anesthetized, mechanically ventilated, and instrumented pigs with human-like coagulation underwent subdural injection of 20 mL of autologous blood and subsequent observation for 54 hours. Continuous bilateral multimodal brain monitoring (intracranial pressure [ICP], cerebral perfusion pressure [CPP], partial pressure of oxygen in brain tissue [PbtO2], and brain temperature) was combined with intermittent neurological assessment (veterinary modified Glasgow Coma Scale [MGCS]), microdialysis, and measurement of plasma protein S100ß, GFAP, neuron-specific enolase [NSE], nitrite+nitrate, and isoprostanes. Fluid resuscitation and continuous intravenous norepinephrine were targeted to maintain CPP at pre-ASDH levels. Immediately postmortem, the brains were taken for macroscopic and histological evaluation, immunohistochemical analysis for nitrotyrosine formation, albumin extravasation, NADPH oxidase 2 (NOX2) and GFAP expression, and quantification of tissue mitochondrial respiration. RESULTS: Nine of 11 pigs survived the complete observation period. While ICP significantly increased after ASDH induction, CPP, PbtO2, and the MGCS score remained unaffected. Blood S100ß levels significantly fell over time, whereas GFAP, NSE, nitrite+nitrate, and isoprostane concentrations were unaltered. Immunohistochemistry showed nitrotyrosine formation, albumin extravasation, NOX2 expression, fibrillary astrogliosis, and microglial activation. CONCLUSIONS: The authors describe a clinically relevant, long-term, resuscitated porcine model of ASDH-induced brain injury. Despite the morphological injury, maintaining CPP and PbtO2 prevented serious neurological dysfunction. This model is suitable for studying therapeutic interventions during hemorrhage-induced acute brain injury with standard brain-targeted intensive care.

Desmopressin acetate in intracranial haemorrhage.

Introduction. The secondary increase in the size of intracranial haematomas as a result of spontaneous haemorrhage or trauma is of particular relevance in the event of prior intake of platelet aggregation inhibitors. We describe the effect of desmopressin acetate as a means of temporarily stabilising the platelet function. Patients and Methods. The platelet function was analysed in 10 patients who had received single (N = 4) or multiple (N = 6) doses of acetylsalicylic acid and 3 patients (control group) who had not taken acetylsalicylic acid. All subjects had suffered intracranial haemorrhage. Analysis was performed before, half an hour and three hours after administration of desmopressin acetate. Statistical analysis was performed by applying a level of significance of P ≤ 0.05. Results. (1) Platelet function returned to normal 30 minutes after administration of desmopressin acetate. (2) The platelet function worsened again after three hours. (3) There were no complications related to electrolytes or fluid balance. Conclusion. Desmopressin acetate can stabilise the platelet function in neurosurgical patients who have received acetylsalicylic acid prior to surgery without causing transfusion-related side effects or a loss of time. The effect is, however, limited and influenced by the frequency of drug intake. Further controls are needed in neurosurgical patients.

Early cranioplasty may improve outcome in neurological patients with decompressive craniectomy.

PRIMARY OBJECTIVE: Decompressive craniectomy is an effective therapy to relieve intractable intracranial hypertension following acute brain injury. However, little is known about the optimal timing for cranioplasties in the sub-acute phase. The objective of the present study was to analyse the effect of cranioplasty timing on neurological outcomes. RESEARCH DESIGN: Single-centre observational study. METHODS AND PROCEDURES: One hundred and forty-seven consecutive patients with decompressive craniectomy and cranioplasty during the course of inpatient neurorehabilitation were identified by means of a retrospective hospital database search. This database contains the following prospectively-entered weekly scores: Barthel-Index (BI), Functional Independence Measure (FIM) and Coma Remission Scale (CRS). Additional clinical data were taken retrospectively from patient charts. Regression analysis was used to identify factors that influenced the end-of-rehabilitation outcome. MAIN OUTCOMES AND RESULTS: Patients with shorter delays to cranioplasty (<86 days) had a better functional outcome than patients with longer delays of >85 days (60 ± 29.5 versus 25 ± 24.1 BI points; p < 0.01, respectively). Age, pre-operative BI and CRS scores were additional independent outcome factors. Complication rates were not different between early and late cranioplasty groups. CONCLUSIONS: Patients with decompressive craniectomy for management of intracranial hypertension may benefit from early cranioplasty.

Impaired crosstalk between pulsatile insulin and glucagon secretion in prediabetic individuals.

INTRODUCTION: Postprandial hyperglucagonemia is frequently found in patients with diabetes. Recently, a loss of the inverse relationship between pulsatile insulin and glucagon secretion has been reported in patients with type 2 diabetes. The crosstalk between pulsatile islet hormone secretion in prediabetic individuals has not yet been examined. PATIENTS AND METHODS: Eleven individuals with impaired glucose tolerance and/or impaired fasting glucose and 13 nondiabetic controls were examined after mixed meal ingestion. Glucose, insulin, and glucagon levels were determined frequently and analyzed by deconvolution and cross-correlation methods. RESULTS: Postprandial glucose levels were higher in prediabetic individuals (P = 0.017). Insulin concentrations were not different between the groups (P = 0.29). Postprandial glucagon levels were higher in the impaired glucose tolerance/impaired fasting glucose individuals (P = 0.039). Pulsatile insulin and glucagon secretion was apparent in both groups, but there were no differences in the frequency or mass of insulin and glucagon pulses between the groups. An inverse relationship between the insulin and glucagon concentration time curves was found in the control subjects (P < 0.05). This association was not detectable in the prediabetic individuals. CONCLUSIONS: Increased postprandial glucagon concentrations in prediabetic individuals are accompanied by a loss of the pulsatile insulin-glucagon crosstalk. This suggests that disturbances in islet hormone pulsatility precede the actual manifestation of hyperglycemia.

Variations of the aortic arch - a study on the most common branching patterns.

BACKGROUND: Anatomical variants of the aortic arch and its branching patterns often appear as an incidental finding during routine computed tomography (CT) scanning. These variations can be of relevance when performing angiography or endovascular interventions and may cause symptoms such as dysphagia. PURPOSE: To analyze common anatomical variations found within the arteries originating from the aortic arch in patients using contrast CT imaging techniques. MATERIAL AND METHODS: A total of 2033 contrast CT scans were analyzed. To obtain a truly representative sample, cases were chosen from different hospital departments without previous knowledge of the patient history. RESULTS: The total percentage of variations within the analyzed patients was 13.3%. In 8.0% a truncus bicaroticus was found. 4.2% of the patients showed a left vertebral artery originating directly from the aortic arch, mostly proximal, and in 1 case distal to the left subclavian artery. In 1.0% we found an aberrant right subclavian artery. We also found a single case of a right descending aortic arch. CONCLUSION: Variations of the aortic arch and its branching are frequently found, mostly as an incidental finding during routine diagnostic scanning. A contrast-enhanced CT scan is a good method with which to study the aortic arch and its associated branching pattern.