Early-stage minimally invasive procedures decrease perihematomal endothelin-1 levels and improve neurological functioning in a rabbit model of intracerebral hemorrhage

Influence of Blood Components on Neuroinflammation, Blood-Brain Barrier Breakdown, and Functional Damage After Acute Subdural Hematoma in Rats

A central component of injury development after acute subdural hematoma (ASDH) is the increased intracranial pressure and consecutive mechanical reduction of cerebral blood flow (CBF). However, the role of different blood constituents in ASDH as additional lesioning factors remains unclear. This study examines the influence of blood components on neuroinflammation, blood-brain barrier (BBB) breakdown, and functional deficits in a rat model of ASDH. We infused corpuscular (whole blood, whole blood lysate, and red cell blood) and plasmatic (blood plasma, anticoagulated blood plasma, and aqueous isotonic solution) blood components into the subdural space while CBF was monitored. Rats then underwent behavioral testing. Lesion analysis and immunohistochemistry were performed 2 days after ASDH. Inflammatory reaction was assessed using staining for ionized calcium-binding adaptor molecule 1 and glial fibrillary acidic protein, interleukin-1ß, tumor necrosis factor-alpha, and membrane attack complex. Integrity of the BBB was evaluated with albumin and matrix metalloproteinase 9 (MMP9) staining. We observed a significant drop in CBF in the corpuscular group (75% ± 7.5% of baseline) with distinct post-operative deficits and larger lesion volume compared to the plasmatic group (13.6 ± 5.4 vs. 1.3 ± 0.4 mm3). Further, inflammation was significantly increased in the corpuscular group with stronger immunoreaction. After whole blood infusion, albumin and MMP9 immunoreaction were significantly increased, pointing toward a disrupted BBB. The interaction between corpuscular and plasmatic blood components seems to be a key factor in the detrimental impact of ASDH. This interaction results in neuroinflammation and BBB leakage. These findings underscore the importance of performing surgery as early as possible and also provide indications for potential pharmacological targets.

When the Blood Hits Your Brain: The Neurotoxicity of Extravasated Blood

Hemorrhage in the central nervous system (CNS), including intracerebral hemorrhage (ICH), intraventricular hemorrhage (IVH), and aneurysmal subarachnoid hemorrhage (aSAH), remains highly morbid. Trials of medical management for these conditions over recent decades have been largely unsuccessful in improving outcome and reducing mortality. Beyond its role in creating mass effect, the presence of extravasated blood in patients with CNS hemorrhage is generally overlooked. Since trials of surgical intervention to remove CNS hemorrhage have been generally unsuccessful, the potent neurotoxicity of blood is generally viewed as a basic scientific curiosity rather than a clinically meaningful factor. In this review, we evaluate the direct role of blood as a neurotoxin and its subsequent clinical relevance. We first describe the molecular mechanisms of blood neurotoxicity. We then evaluate the clinical literature that directly relates to the evacuation of CNS hemorrhage. We posit that the efficacy of clot removal is a critical factor in outcome following surgical intervention. Future interventions for CNS hemorrhage should be guided by the principle that blood is exquisitely toxic to the brain.

Is the CT Blend Sign Composed of Two Parts of Blood with Different Age?

BACKGROUND

Blend sign on initial computed tomography (CT) is associated with poor outcome in patients with intracerebral hemorrhage (ICH). However, the mechanisms underlying the blend sign formation are poorly understood. The present study aimed to explore the possible mechanism of the CT blend sign in patients with ICH.

METHODS

Seventy healthy rabbits were selected to prepare an ICH model. The animals were assigned to a whole blood group + whole blood group (ww group, 50 rabbits), a whole blood + plasma group (wp group, 10 rabbits) or a whole blood + serum group (ws group, 10 rabbits). The animals of the ww group were allocated to five subgroups based on the interval between the first infusion of blood and the second one. The subgroups included ww 1 h group (with an interval of 1 h), ww 2 h group, ww 3 h group, ww 4 h group and ww 5 h group. The rabbits from each group received first infusion of 0.3 mL of whole blood into the basal ganglia area to form a hematoma. Then, they received a second infusion of the same amount of whole blood, plasma or serum into the brain to form another hematoma adjacent to the first one.

RESULTS

A hematoma with two densities on brain CT could be formed in each group after a second infusion of blood into the brain. A significant difference in CT attenuation values was observed between the hyperattenuation and the hypoattenuation in all the groups. However, only the morphological features of the hematoma in the ww group was in accordance with the CT blend sign observed in humans. The CT attenuation values in the hypodensity area of the ww 4 h group or the ww 5 h group were decreased compared with the ww 1 h group to the ww 3 h group.

CONCLUSIONS

The CT blend sign observed in humans might be composed of two parts of blood with different ages. The hypodense area might be blood with older age and the hyperdense area might be new bleeding.

Rosiglitazone Infusion Therapy Following Minimally Invasive Surgery for Intracranial Hemorrhage Evacuation Decreased Perihematomal Glutamate Content and Blood-Brain Barrier Permeability in Rabbits

OBJECTIVE

To observe effects of rosiglitazone (RSG) infusion therapy on perihematomal peroxisome-proliferator-activated receptor gamma (PPARγ), glutamate, blood-brain barrier (BBB) permeability, and brain edema.

METHODS

Fifty male rabbits (2.8-3.4 kg) were randomly assigned to a normal control (NC) group, model control (MC) group, RSG group, minimally invasive surgery (MIS) group, or MIS and RSG (MIS+RSG) group. Intracranial hemorrhage was induced in all rabbits except for the NC group. MIS procedures were performed to evacuate the intracranial hemorrhage 6 hours after the intracranial hemorrhage model was prepared successfully. The animals were sacrificed on day 7, and the perihematomal brain tissue was obtained to determine PPARγ, glutamate, and BBB permeability.

RESULTS

Compared with the MC group, the MIS group displayed a remarkable decrease in PPARγ, glutamate, and BBB permeability. The RSG group showed similar results in glutamate level and BBB permeability but a significant increase in PPARγ. The MIS+RSG group displayed an increase in PPARγ and a more significant decrease in glutamate, BBB permeability, and neurologicl deficit scores compared with the other groups.

CONCLUSIONS

Performing MIS followed by RSG infusion therapy might increase PPARγ expression and might be more efficacious for reducing glutamate level and BBB permeability and improving neurologic function than MIS or RSG therapy used alone.