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1.
Mol Neurobiol ; 60(10): 5607-5623, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37328678

ABSTRACT

Decompressive craniectomy (DC) is a major form of surgery that is used to reduce intracranial hypertension (IH), the most frequent cause of death and disability following severe traumatic brain injury (sTBI) and stroke. Our previous research showed that controlled decompression (CDC) was more effective than rapid decompression (RDC) with regard to reducing the incidence of complications and improving outcomes after sTBI; however, the specific mechanisms involved have yet to be elucidated. In the present study, we investigated the effects of CDC in regulating inflammation after IH and attempted to identify the mechanisms involved. Analysis showed that CDC was more effective than RDC in alleviating motor dysfunction and neuronal death in a rat model of traumatic intracranial hypertension (TIH) created by epidural balloon pressurization. Moreover, RDC induced M1 microglia polarization and the release of pro-inflammatory cytokines. However, CDC treatment resulted in microglia primarily polarizing into the M2 phenotype and induced the significant release of anti-inflammatory cytokines. Mechanistically, the establishment of the TIH model led to the increased expression of hypoxia-inducible factor-1α (HIF-1α); CDC ameliorated cerebral hypoxia and reduced the expression of HIF-1α. In addition, 2-methoxyestradiol (2-ME2), a specific inhibitor of HIF-1α, significantly attenuated RDC-induced inflammation and improved motor function by promoting M1 to M2 phenotype transformation in microglial and enhancing the release of anti-inflammatory cytokines. However, dimethyloxaloylglycine (DMOG), an agonist of HIF-1α, abrogated the protective effects of CDC treatment by suppressing M2 microglia polarization and the release of anti-inflammatory cytokines. Collectively, our results indicated that CDC effectively alleviated IH-induced inflammation, neuronal death, and motor dysfunction by regulating HIF-1α-mediated microglial phenotype polarization. Our findings provide a better understanding of the mechanisms that underlie the protective effects of CDC and promote clinical translational research for HIF-1α in IH.


Subject(s)
Brain Injuries, Traumatic , Intracranial Hypertension , Rats , Animals , Microglia/metabolism , Signal Transduction , Inflammation/metabolism , Anti-Inflammatory Agents/pharmacology , Brain Injuries, Traumatic/metabolism , Intracranial Hypertension/drug therapy , Intracranial Hypertension/metabolism , Cytokines/metabolism , Decompression , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism
2.
J Neuroimmunol ; 373: 577976, 2022 12 15.
Article in English | MEDLINE | ID: mdl-36270079

ABSTRACT

BACKGROUND: Glial fibrillary acidic protein (GFAP) astrocytopathy is a steroid-responsive autoimmune meningoencephalomyelitis commonly preceded by a viral illness. It is clinically characterized by encephalopathy, myelopathy and papillitis without significant effect on visual acuity. It can be associated with an underlying malignancy or autoimmune condition. OBJECTIVE: To report a novel case of GFAP astrocytopathy presenting with profound intracranial hypertension and bilateral vision loss. METHODS: Case report. RESULTS AND CONCLUSION: GFAP astrocytopathy should be considered when evaluating patients with intracranial hypertension or bilateral vision loss, particularly when other features of autoimmune encephalitis are present.


Subject(s)
Autoimmune Diseases , Encephalitis , Intracranial Hypertension , Humans , Glial Fibrillary Acidic Protein/metabolism , Astrocytes/metabolism , Encephalitis/pathology , Autoimmune Diseases/pathology , Intracranial Hypertension/complications , Intracranial Hypertension/diagnosis , Intracranial Hypertension/metabolism , Vision Disorders/etiology , Autoantibodies
4.
World Neurosurg ; 141: 115-118, 2020 09.
Article in English | MEDLINE | ID: mdl-32526359

ABSTRACT

BACKGROUND: Pediatric cerebral malaria (CM) is a severe complication of Plasmodium falciparum that often leaves survivors with severe neurologic impairment. Increased intracranial pressure (ICP) as a result of cerebral edema has been identified as a major predictor of morbidity and mortality in CM. Past studies have demonstrated that survivors are more likely to have resolution of elevated ICP and that efficient management of ICP crises may lead to better outcomes. However, data on invasive brain tissue oxygen monitoring are unknown. CASE DESCRIPTION: We report a case of a pediatric patient with cerebral malaria who developed encephalopathy and cerebral edema and describe the pathophysiology of this disease process with invasive ICP and brain tissue oxygen multimodality neuromonitoring. The utilization of both ICP and brain tissue oxygen monitoring allowed prompt diagnosis and successful treatment of severe intracranial hypertension and low brain tissue oxygenation crisis. The patient was discharged to home in good neurologic condition. CONCLUSIONS: Multimodality neuromonitoring may be considered in pediatric patients who have cerebral edema and encephalopathy from CM.


Subject(s)
Brain/metabolism , Intracranial Hypertension/diagnosis , Malaria, Cerebral/complications , Malaria, Falciparum/complications , Oxygen/analysis , Adolescent , Brain/diagnostic imaging , Female , Humans , Intracranial Hypertension/etiology , Intracranial Hypertension/metabolism , Malaria, Cerebral/metabolism , Malaria, Falciparum/metabolism , Monitoring, Physiologic/methods , Oxygen Consumption
5.
Front Endocrinol (Lausanne) ; 11: 613054, 2020.
Article in English | MEDLINE | ID: mdl-33488525

ABSTRACT

Idiopathic Intracranial Hypertension is a neurological disorder primarily affecting overweight women of childbearing age. It is often characterized by radiologic evidence of empty sella (ES), which is in turn frequently associated with pituitary dysfunction, with the somatotropic axis most commonly affected. No recent evidence is available relative to the presence of pituitary hormone deficiencies in adult patients with Idiopathic Intracranial Hypertension (IIH) under pharmacological therapy. We therefore explored pituitary function and morphology in a small cohort of female patients with IIH treated with acetazolamide. Fifteen female patients aged 42 ± 13 years with IIH lasting between 12 and 18 months were evaluated. All patients were affected by recurrent headaches in addition to visual changes of variable severity. IIH diagnosis was made after exclusion of other causes of raised intracranial pressure, and a specific ophthalmological evaluation was conducted to assess for the presence of papilledema. No particular endocrinological disturbances were detected during the enrolment visits, except for a high obesity prevalence (87%, BMI 35.16 ± 8.21 kg/m2), one case of total thyroidectomy for papillary thyroid carcinoma and two patients with irregular menses and mild hirsutism. All the participants underwent a pituitary MRI with contrast, and two different operators performed pituitary measurements in coronal and sagittal scans for morphologic assessment. Blood samples for the anterior pituitary axis evaluation were collected, and the somatotropic axis was further evaluated with a GHRH + Arginine test; other dynamic tests were performed in case of suspected hormonal deficiency. Despite ES being found in 73% of the patients, pituitary volume was preserved, ranging from 213.85 to 642.27mm3 (389.20 ± 125.53mm3); mean coronal pituitary height was 4.53 ± 1.33 mm. Overall, baseline anterior pituitary hormones levels were within normal ranges, and none of the patients with ES had an altered response to the GHRH + arginine stimulation test. We found one patient suffering from iatrogenic hyperthyroidism and two diagnosed with subclinical primary hypothyroidism due to Hashimoto's thyroiditis. Two young patients were suspected of having polycystic ovary syndrome, and they were therefore further investigated. In conclusion, this case series shows that, despite the high prevalence of ES, the pituitary function of IIH patients treated with acetazolamide is preserved. To date, there is no evidence regarding the trend over time or upon treatment discontinuation in regard to the pituitary function of patients with IIH, and it is therefore not possible to infer whether our finding would be replicable in such settings. We therefore suggest an endocrine follow-up over time in order to monitor for potential pituitary dysfunction.


Subject(s)
Acetazolamide/therapeutic use , Diuretics/therapeutic use , Intracranial Hypertension/diagnostic imaging , Intracranial Hypertension/drug therapy , Pituitary Gland/diagnostic imaging , Acetazolamide/pharmacology , Adolescent , Adult , Diuretics/pharmacology , Female , Humans , Intracranial Hypertension/metabolism , Middle Aged , Pituitary Gland/drug effects , Pituitary Gland/metabolism , Treatment Outcome , Young Adult
6.
Neurocrit Care ; 32(2): 437-447, 2020 04.
Article in English | MEDLINE | ID: mdl-31240622

ABSTRACT

BACKGROUND: Raised intracranial pressure (ICP) is a prominent cause of morbidity and mortality after severe traumatic brain injury (TBI). However, in the clinical setting, little is known about the cerebral physiological response to severe and prolonged increases in ICP. METHODS: Thirty-three severe TBI patients from a single center who developed severe refractory intracranial hypertension (ICP > 40 mm Hg for longer than 1 h) with ICP, arterial blood pressure, and brain tissue oxygenation (PBTO2) monitoring (subcohort, n = 9) were selected for retrospective review. Secondary parameters reflecting autoregulation (including pressure reactivity index-PRx, which was available in 24 cases), cerebrospinal compensatory reserve (RAP), and ICP pulse amplitude were calculated. RESULTS: PRx deteriorated from 0.06 ± 0.26 a.u. at baseline levels of ICP to 0.57 ± 0.24 a.u. (p < 0.0001) at high levels of ICP (> 50 mm Hg). In 4 cases, PRx was impaired (> 0.25 a.u.) before ICP was raised above 25 mm Hg. Concurrently, PBTO2 decreased from 27.3 ± 7.32 mm Hg at baseline ICP to 12.68 ± 7.09 mm Hg at high levels of ICP (p < 0.001). The pulse amplitude of the ICP waveform increased with increasing ICP but showed an 'upper breakpoint'-whereby further increases in ICP lead to decreases in pulse amplitude-in 6 out of the 33 patients. DISCUSSION: Severe intracranial hypertension after TBI leads to decreased brain oxygenation, impaired pressure reactivity, and changes in the pulse amplitude of ICP. Impaired pressure reactivity may denote increased risk of developing refractory intracranial hypertension in some patients.


Subject(s)
Arterial Pressure/physiology , Brain Injuries, Traumatic/physiopathology , Brain/physiopathology , Cerebrovascular Circulation/physiology , Intracranial Hypertension/physiopathology , Oxygen/metabolism , Adolescent , Adult , Brain/metabolism , Brain Injuries, Traumatic/complications , Brain Injuries, Traumatic/metabolism , Decompressive Craniectomy , Female , Glasgow Coma Scale , Homeostasis , Humans , Intracranial Hypertension/etiology , Intracranial Hypertension/metabolism , Male , Mortality , Retrospective Studies , Severity of Illness Index , Time Factors , Young Adult
7.
Neuro Endocrinol Lett ; 39(3): 209-218, 2018 Sep.
Article in English | MEDLINE | ID: mdl-30431738

ABSTRACT

OBJECTIVES: This paper presents our own rat model of the cellular brain edema, induced by water intoxication (WI). The basic principle of the model is an osmotic imbalance in the cell membrane followed by an intracellular flow of sodium and simultaneous accumulation of water leading to the subsequent increase of BBB permeability. METHODS: The usefulness of the model was tested in precisely specified conditions whose results were clearly expressed. The procedure determined both how WI induces cellular edema as well as the disturbances caused by cellular edema. RESULTS: The evidence of existing cellular edema with increased BBB permeability was proved by intracellular accumulation of intravital dye with a large molecular size; increased brain-water content was confirmed by using the dry/wet weight method and by the decrease in CT density; the elevated intracranial pressure (ICP) due to the expanding volume was determined by continuous monitoring the ICP; the structural lesions were proved by identification of the myelin disintegration; and the impaired nervous functions was demonstrated by the of open field test method. CONCLUSION: Our experimental model can help the future studies of pathophysiology of cellular brain edema and is suitable for testing neuroprotective agents.


Subject(s)
Behavior, Animal , Brain Edema/physiopathology , Disease Models, Animal , Intracranial Hypertension/physiopathology , Locomotion , Rats , Water Intoxication/physiopathology , Animals , Blood-Brain Barrier/metabolism , Brain/diagnostic imaging , Brain/metabolism , Brain/pathology , Brain Edema/etiology , Brain Edema/metabolism , Brain Edema/pathology , Evans Blue , Intracranial Hypertension/etiology , Intracranial Hypertension/metabolism , Intracranial Hypertension/pathology , Male , Myelin Sheath/pathology , Permeability , Rats, Wistar , Tomography, X-Ray Computed , Water Intoxication/complications , Water Intoxication/metabolism , Water Intoxication/pathology
8.
Curr Neurol Neurosci Rep ; 18(11): 74, 2018 09 11.
Article in English | MEDLINE | ID: mdl-30206730

ABSTRACT

PURPOSE OF THE REVIEW: The aims of fluid management in acute brain injury are to preserve or restore physiology and guarantee appropriate tissue perfusion, avoiding potential iatrogenic effects. We reviewed the literature, focusing on the clinical implications of the selected papers. Our purposes were to summarize the principles regulating the distribution of water between the intracellular, interstitial, and plasma compartments in the normal and the injured brain, and to clarify how these principles could guide fluid administration, with special reference to intracranial pressure control. RECENT FINDINGS: Although a considerable amount of research has been published on this topic and in general on fluid management in acute illness, the quality of the evidence tends to vary. Intravascular volume management should aim for euvolemia. There is evidence of harm with aggressive administration of fluid aimed at achieving hypervolemia in cases of subarachnoid hemorrhage. Isotonic crystalloids should be the preferred agents for volume replacement, while colloids, glucose-containing hypotonic solutions, and other hypotonic solutions or albumin should be avoided. Osmotherapy seems to be effective in intracranial hypertension management; however, there is no clear evidence regarding the superiority of hypertonic saline over mannitol. Fluid therapy plays an important role in the management of acute brain injury patients. However, fluids are a double-edged weapon because of the potential risk of hyper-hydration, hypo- or hyper-osmolar conditions, which may unfavorably affect the clinical course and the outcome.


Subject(s)
Brain Injuries/therapy , Disease Management , Fluid Therapy/methods , Saline Solution, Hypertonic/therapeutic use , Brain Injuries/complications , Brain Injuries/metabolism , Humans , Intracranial Hypertension/drug therapy , Intracranial Hypertension/etiology , Intracranial Hypertension/metabolism , Intracranial Pressure/drug effects , Intracranial Pressure/physiology , Randomized Controlled Trials as Topic/methods , Saline Solution, Hypertonic/pharmacology , Subarachnoid Hemorrhage/etiology , Subarachnoid Hemorrhage/metabolism , Subarachnoid Hemorrhage/therapy
9.
World Neurosurg ; 120: e161-e168, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30096502

ABSTRACT

BACKGROUND: Cerebral venous infarction (CVI) is a rare vascular disease most commonly caused by cerebral venous thrombosis that leads to hemorrhage or infarct formation. A rabbit model of CVI was established by placing a recoverable epidural sacculus to research effects of increased pressure on CVI. METHODS: Rabbits were randomly divided into the following groups: A, CVI; B, 0.2-mL epidural sacculus placed on the basis of CVI; C, 0.4-mL epidural sacculus; D, 0.6-mL epidural sacculus; E, sham operation. Two sacculus-release groups were then added, 8 hours (group F) and 24 hours (group G), on the basis of group D. Brain water content, extent of cerebral infarction, hemorheology indexes, D dimer, and fibrinogen were observed at 8, 24, and 48 hours after surgery. RESULTS: Brain water content was higher in groups A-D compared with group E with the exception of the 24-hour A group. Brain water content was significantly lower in sacculus-release groups compared with the 48-hour D group. Extent of cerebral infarction in group D was significantly higher at 24 and 48 hours compared with groups A and E. Extent of cerebral infarction in sacculus-release groups was significantly lower compared with group D at 48 hours. Hemorheology indexes and fibrinogen were significantly higher in group D compared with groups A and E at corresponding time points and increased with increasing intracranial pressure. CONCLUSIONS: In the rabbit model of CVI, degree of brain edema, extent of cerebral infarction, hemorheology indexes, and fibrinogen increased as intracranial pressure gradient increased, which may promote formation of a hypercoagulable state. Early removal of intracranial hypertension reduced degree of edema and extent of cerebral infarction in rabbits.


Subject(s)
Brain Edema/physiopathology , Brain Infarction/physiopathology , Cerebral Veins , Intracranial Hypertension/physiopathology , Sinus Thrombosis, Intracranial/diagnosis , Animals , Brain Edema/etiology , Brain Infarction/etiology , Brain Infarction/metabolism , Diagnostic Errors , Disease Models, Animal , Fibrin Fibrinogen Degradation Products/metabolism , Fibrinogen/metabolism , Hemorheology , Intracranial Hypertension/etiology , Intracranial Hypertension/metabolism , Intracranial Pressure , Rabbits , Severity of Illness Index , Sinus Thrombosis, Intracranial/complications
10.
Brain Behav ; 8(6): e01005, 2018 06.
Article in English | MEDLINE | ID: mdl-29791061

ABSTRACT

OBJECTIVE: Introduce and evaluate a new model which explains the release of brain antidiuretic hormone (ADH) independent of plasma osmolality. METHODS: Systematic review and critical analysis of the professional literature. RESULTS: Primary electronic database searches using key terms revealed 57,432 hits. Secondary searches with application of specific inclusion and exclusion criteria and manual inspection for completeness reduced the total number of studies to fourteen (N = 14). Twelve (N = 12) studies investigated human subjects in the hospital settings, and two (N = 2) studies investigated animals (rhesus monkeys and dog) under invasive experimental conditions. All fourteen studies included direct or indirect indicators of intracranial pressure (ICP), measurements of plasma ADH, and plasma osmolality or urine osmolality. Findings, in brief, reveal a stable and positive association between increased intracranial pressure (ICP) and increased ADH release, in patients with low or normal blood osmolality. Findings are reliable and reproducible across human and animal populations. CONCLUSIONS: Findings support the proposed model, which explains increase secretion of brain ADH when plasma osmolality is low or within normal limits. Mechanical pressures exerted on hypothalamic nuclei, especially paraventricular and supra-optic nuclei, as a consequence of increased intracranial pressure, produce release of ADH, independent of plasma osmolality. The mechanical pressure model explains release of ADH previously unexplained by traditional plasma osmolality models. Findings have important clinical implications for the medical and surgical management of patients.


Subject(s)
Intracranial Hypertension/etiology , Vasopressins/metabolism , Animals , Female , Humans , Intracranial Hypertension/blood , Intracranial Hypertension/metabolism , Intracranial Pressure/physiology , Male , Neurophysins/metabolism , Osmolar Concentration , Protein Precursors/metabolism
11.
Bratisl Lek Listy ; 119(3): 139-142, 2018.
Article in English | MEDLINE | ID: mdl-29536741

ABSTRACT

AIM: The aim of this study was to analyse the relationship between intracranial pressure (intracranial pressure monitoring) and lactate pyruvate ratio (cerebral microdialysis) in patients with ruptured intracranial aneurysms. METHODS: In a group of fifteen patients, intracranial pressure and lactate/pyruvate ratios were measured and logged in hourly intervals. The relationship between these two variables was subsequently analysed in two ways. 1) Intracranial hypertension (ICP > 20 mmHg) in the presence of energy deprivation (L/P ratio > 30) was noted. 2) The dynamics of L/P ratio changes in relation to immediate ICP and CPP values was analysed. RESULTS: Out of a total of 1873 monitored hours we were able to record lactate/pyruvate ratios higher than 30 in 832 hours (44 %). Of those 832 hours during which lactate/pyruvate ratios were higher than 30, ICP was higher than 20 in 193 hours (23 %). Out of 219 hours of monitoring, in which ICP was higher than 20, a simultaneously increased L/P ratio higher than 30 was recorded in 193 hours (88 %). L/P ratio values above 30 were associated with decreased CPP values (p = 0.04), but not with increased ICP values (p = 0.79). CONCLUSION: Intracranial hypertension coincides with energetic imbalance in approximately one quarter of cases. This points to the shortcomings of the most common form of neuromonitoring in SAH patients - ICP monitoring. This method may not be reliable enough in detecting hypoxic damage, which is the major cause of morbidity and mortality in SAH patients (Fig. 5, Ref. 11).


Subject(s)
Brain/metabolism , Intracranial Hypertension/metabolism , Intracranial Pressure , Lactic Acid/metabolism , Pyruvic Acid/metabolism , Subarachnoid Hemorrhage/metabolism , Aneurysm, Ruptured/complications , Aneurysm, Ruptured/metabolism , Aneurysm, Ruptured/physiopathology , Brain/physiopathology , Humans , Intracranial Aneurysm/complications , Intracranial Aneurysm/metabolism , Intracranial Aneurysm/physiopathology , Intracranial Hypertension/etiology , Intracranial Hypertension/physiopathology , Microdialysis , Monitoring, Physiologic , Subarachnoid Hemorrhage/etiology , Subarachnoid Hemorrhage/physiopathology
12.
Acta Neurochir Suppl ; 126: 93-95, 2018.
Article in English | MEDLINE | ID: mdl-29492540

ABSTRACT

OBJECTIVE: High-frequency pulsed electromagnetic field (PEMF) stimulation is an emerging noninvasive therapy that we have shown increases cerebral blood flow (CBF) and tissue oxygenation in the healthy rat brain. In this work, we tested the effect of PEMF on the brain at high intracranial pressure (ICP). We previously showed that high ICP in rats caused a transition from capillary (CAP) to non-nutritive microvascular shunt (MVS) flow, tissue hypoxia and increased blood brain barrier (BBB) permeability. METHODS: Using in vivo two-photon laser scanning microscopy (2PLSM) over the rat parietal cortex, and studied the effects of PEMF on microvascular blood flow velocity, tissue oxygenation (NADH autofluorescence), BBB permeability and neuronal necrosis during 4 h of elevated ICP to 30 mmHg. RESULTS: PEMF significantly dilated arterioles, increased capillary blood flow velocity and reduced MVS/capillary ratio compared to sham-treated animals. These effects led to a significant decrease in tissue hypoxia, BBB degradation and neuronal necrosis. CONCLUSIONS: PEMF attenuates high ICP-induced pathological microcirculatory changes, tissue hypoxia, BBB degradation and neuronal necrosis.


Subject(s)
Blood-Brain Barrier/metabolism , Cerebrovascular Circulation/physiology , Hypoxia/metabolism , Intracranial Hypertension/therapy , Magnetic Field Therapy/methods , Microvessels/physiopathology , Parietal Lobe/blood supply , Permeability , Animals , Electromagnetic Fields , Hydroxyethylrutoside , Hypoxia/etiology , Intracranial Hypertension/complications , Intracranial Hypertension/metabolism , Intracranial Hypertension/physiopathology , Intravital Microscopy , Male , Microscopy, Confocal , Microvessels/pathology , Parietal Lobe/metabolism , Parietal Lobe/pathology , Rats , Rats, Sprague-Dawley
13.
Acta Neurochir Suppl ; 126: 309-312, 2018.
Article in English | MEDLINE | ID: mdl-29492580

ABSTRACT

OBJECTIVE: In previous work we showed that high intracranial pressure (ICP) in the rat brain induces a transition from capillary (CAP) to pathological microvascular shunt (MVS) flow, resulting in brain hypoxia, edema, and blood-brain barrier (BBB) damage. This transition was correlated with a loss of cerebral blood flow (CBF) autoregulation undetected by static autoregulatory curves but identified by induced dynamic ICP (iPRx) and cerebrovascular (iCVRx) reactivity. We hypothesized that loss of CBF autoregulation as correlated with MVS flow would be identified by iPRx and iCVRx in traumatic brain injury (TBI) with elevated ICP. METHODS: TBI was induced by lateral fluid percussion (LFP) using a gas-driven device in rats. Using in vivo two-photon laser scanning microscopy, cortical microcirculation, tissue oxygenation (NADH autofluoresence), and BBB permeability (fluorescein dye extravasation) were measured before and for 4 h after TBI. Laser Doppler cortical flux, rectal and brain temperature, ICP and mean arterial pressure (MAP), blood gases, and electrolytes were monitored. Every 30 min, a transient 10 mmHg rise in MAP was induced by i.v. bolus of dopamine. iPRx = ΔICP/ΔMAP and iCVRx = ΔCBF/ΔMAP. RESULTS: We demonstrated that iPRx and iCVRx correctly identified more severe loss of CBF autoregulation correlated with a transition of blood flow to MVS after TBI with high ICP compared to TBI without an increase in ICP. CONCLUSIONS: In TBI with high ICP, high-velocity MVS flow is responsible for the loss of CBF autoregulation identified by iPRx and iCVRx.


Subject(s)
Brain Injuries, Traumatic/physiopathology , Cerebral Cortex/physiopathology , Cerebrovascular Circulation/physiology , Homeostasis/physiology , Intracranial Hypertension/physiopathology , Microcirculation/physiology , Animals , Blood-Brain Barrier/metabolism , Brain Injuries, Traumatic/metabolism , Brain Injuries, Traumatic/pathology , Cerebral Cortex/blood supply , Cerebral Cortex/pathology , Intracranial Hypertension/metabolism , Intracranial Hypertension/pathology , Intracranial Pressure , Intravital Microscopy , Male , Microscopy, Confocal , Permeability , Rats , Rats, Sprague-Dawley
14.
Sci Rep ; 8(1): 2856, 2018 02 12.
Article in English | MEDLINE | ID: mdl-29434244

ABSTRACT

Elevated intracranial pressure (ICP) can result in multiple neurologic sequelae including vision loss. Inducible models of ICP elevation are lacking in model organisms, which limits our understanding of the mechanism by which increased ICP impacts the visual system. We adapted a mouse model for the sustained elevation of ICP and tested the hypothesis that elevated ICP impacts the optic nerve and retinal ganglion cells (RGCs). ICP was elevated and maintained for 2 weeks, and resulted in multiple anatomic changes that are consistent with human disease including papilledema, loss of physiologic cupping, and engorgement of the optic nerve head. Elevated ICP caused a loss of RGC somas in the retina and RGC axons within the optic nerve, as well as a reduction in both RGC electrical function and contrast sensitivity. Elevated ICP also caused increased hypoxia-inducible factor (HIF)-1 alpha expression in the ganglion cell layer. These experiments confirm that sustained ICP elevation can be achieved in mice and causes phenotypes that preferentially impact RGCs and are similar to those seen in human disease. With this model, it is possible to model human diseases of elevated ICP such as Idiopathic Intracranial Hypertension and Spaceflight Associated Neuro-ocular Syndrome.


Subject(s)
Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Intracranial Hypertension/complications , Optic Nerve/pathology , Retinal Ganglion Cells/pathology , Animals , Disease Models, Animal , Electroretinography , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Intracranial Hypertension/diagnostic imaging , Intracranial Hypertension/metabolism , Mice , Microscopy, Electron , Optic Nerve/diagnostic imaging , Optic Nerve/metabolism , Phenotype , Retinal Ganglion Cells/metabolism , Tomography, Optical Coherence , Up-Regulation
15.
Methods Mol Biol ; 1717: 37-52, 2018.
Article in English | MEDLINE | ID: mdl-29468582

ABSTRACT

Traumatic brain injury (TBI) is one of the leading causes of death and disability worldwide. It is a silently growing epidemic with multifaceted pathogenesis, and current standards of treatments aim to target only the symptoms of the primary injury, while there is a tremendous need to explore interventions that can halt the progression of the secondary injuries. The use of a reliable animal model to study and understand the various aspects the pathobiology of TBI is extremely important in therapeutic drug development against TBI-associated complications. The controlled cortical impact (CCI) model of TBI described here, uses a mechanical impactor to inflict a mechanical injury into the mouse brain. This method is a reliable and reproducible approach to inflict mild, moderate or severe injuries to the animal for studying TBI-associated blood-brain barrier (BBB) dysfunctions, neuronal injuries, brain edema, neurobehavioral changes, etc. The present method describes how the CCI model could be utilized for determining the BBB dysfunction and hyperpermeability associated with TBI. Blood-brain barrier disruption is a hallmark feature of the secondary injury that occur following TBI, frequently associated with leakage of fluid and proteins into the extravascular space leading to vasogenic edema and elevation of intracranial pressure. The method described here focuses on the development of a CCI-based mouse model of TBI followed by the evaluation of BBB integrity and permeability by intravital microscopy as well as Evans Blue extravasation assay.


Subject(s)
Blood-Brain Barrier , Brain Injuries, Traumatic , Intracranial Hypertension , Animals , Blood-Brain Barrier/metabolism , Blood-Brain Barrier/pathology , Blood-Brain Barrier/physiopathology , Brain Injuries, Traumatic/metabolism , Brain Injuries, Traumatic/pathology , Brain Injuries, Traumatic/physiopathology , Disease Models, Animal , Humans , Intracranial Hypertension/metabolism , Intracranial Hypertension/pathology , Intracranial Hypertension/physiopathology , Mice
16.
Neurosurgery ; 83(6): 1317-1327, 2018 12 01.
Article in English | MEDLINE | ID: mdl-29462373

ABSTRACT

BACKGROUND: The molecular mechanism of brain arteriovenous malformation (BAVM) is largely unknown. Intracranial venous hypertension (VH) may enhance focal angiogenesis and promote BAVM development and progression. A rat VH model effectively simulates the hemodynamic microenvironment of this disease. OBJECTIVE: To explore the effect of doxycycline in VH-related angiogenesis, as well as the role of matrix metalloproteinase-3 (MMP-3) and other molecular factors. METHODS: A rat VH model was generated by common carotid artery and distal external jugular vein anastomosis. Microvessel density (MVD) in the perisinus area and expression of MMP-3/2/9, VEGF, TIMP-1, TGF-ß, and HIF-1α were examined, with and without daily doxycycline treatment for 4 wk. The effects of doxycycline were verified in Vitro using human brain microvascular endothelial cells (HBMECs). MMP-3 overexpression or knockdown in HBMECs was used to confirm the role of MMP-3 in cell functions. RESULTS: MVD in the perisinus cortex was greatly increased after VH. Doxycycline decreased MVD, suppressed MMP-3 overexpression, and reduced VEGF, TGF-ß, and TIMP-1 levels compared with the controls (P < .05). In Vitro, doxycycline decreased HBMEC migration, tube formation, and the mRNA, protein, and enzymatic activity levels of MMP-3. MMP-3 overexpression in HBMECs promoted migration, while knockdown of MMP-3 significantly attenuated proliferation, migration, and tube formation (P < .05). CONCLUSION: Our findings indicate that MMP-3 plays an important role in VH-related angiogenesis and the promotion of vascular remodeling. Suppression of MMP-3 overexpression by doxycycline may provide a potential strategy for inhibiting BAVM development.


Subject(s)
Doxycycline/pharmacology , Intracranial Hypertension/metabolism , Matrix Metalloproteinase 3/metabolism , Neovascularization, Pathologic/metabolism , Vascular Remodeling/drug effects , Animals , Humans , Intracranial Arteriovenous Malformations/metabolism , Male , Rats , Vascular Remodeling/physiology
17.
Sci Rep ; 7(1): 3805, 2017 06 19.
Article in English | MEDLINE | ID: mdl-28630478

ABSTRACT

In recent years, hypopituitarism caused by traumatic brain injury (TBI) has been explored in many clinical studies; however, few studies have focused on intracranial hypertension and stress caused by TBI. In this study, an intracranial hypertension model, with epidural hematoma as the cause, was used to explore the physiopathological and neuroendocrine changes in the hypothalamic-pituitary axis and hippocampus. The results demonstrated that intracranial hypertension increased the apoptosis rate, caspase-3 levels and proliferating cell nuclear antigen (PCNA) in the hippocampus, hypothalamus, pituitary gland and showed a consistent rate of apoptosis within each group. The apoptosis rates of hippocampus, hypothalamus and pituitary gland were further increased when intracranial pressure (ICP) at 24 hour (h) were still increased. The change rates of apoptosis in hypothalamus and pituitary gland were significantly higher than hippocampus. Moreover, the stress caused by surgery may be a crucial factor in apoptosis. To confirm stress leads to apoptosis in the hypothalamus and pituitary gland, we used rabbits to establish a standard stress model. The results confirmed that stress leads to apoptosis of neuroendocrine cells in the hypothalamus and pituitary gland, moreover, the higher the stress intensity, the higher the apoptosis rate in the hypothalamus and pituitary gland.


Subject(s)
Apoptosis , Brain Injuries, Traumatic , Hippocampus , Hypothalamo-Hypophyseal System , Intracranial Hypertension , Intracranial Pressure , Animals , Brain Injuries, Traumatic/metabolism , Brain Injuries, Traumatic/pathology , Brain Injuries, Traumatic/physiopathology , Hippocampus/metabolism , Hippocampus/pathology , Hippocampus/physiopathology , Hypothalamo-Hypophyseal System/metabolism , Hypothalamo-Hypophyseal System/pathology , Hypothalamo-Hypophyseal System/physiopathology , Intracranial Hypertension/metabolism , Intracranial Hypertension/pathology , Intracranial Hypertension/physiopathology , Male , Rats , Rats, Sprague-Dawley
18.
Curr Drug Targets ; 18(12): 1424-1429, 2017.
Article in English | MEDLINE | ID: mdl-27593685

ABSTRACT

BACKGROUND: Subarachnoid hemorrhage (SAH) following rupture of an intracranial is associated with high mortality and morbidity. The late deterioration of the patient's neurological status or late cognitive dysfunctions even after secure clipping or decent endovascular treatment which is defined as delayed ischemic neurological deficits recently has been attributed to vasospasm. Due to the failure of specific anti- vasospastic agents in clinical trials researchers focused to explore new pathological mechanisms to be responsible for the delayed deterioration of the patients suffering from SAH. Early brain injury (EBI), as a new term in the SAH research area has been the focus of scientist for the past couple of years. OBJECTIVE: The goal of this study is to review the common mechanisms of early brain injury and vasospasm. RESULTS: The acute events following SAH, such as increased intracranial pressure and decreased cerebral blood flow, causing global cerebral ischemia initiate a cascade of pathological changes including inflammation, lipid peroxidation, cell death and blood brain barrier disruption. CONCLUSION: The more insight we gain into the EBI we realize that there are a bunch of common mechanisms between EBI and vasospasm. In the SAH management, a therapy targeting these early injuries may also reduce the later developing pathological neurological complications.


Subject(s)
Intracranial Hypertension/complications , Subarachnoid Hemorrhage/physiopathology , Vasospasm, Intracranial/physiopathology , Animals , Blood-Brain Barrier/pathology , Cell Death , Cerebrovascular Circulation , Humans , Intracranial Hypertension/metabolism , Lipid Peroxidation , Subarachnoid Hemorrhage/complications , Subarachnoid Hemorrhage/metabolism , Vasospasm, Intracranial/metabolism
20.
Rev. neurol. (Ed. impr.) ; 63(10): 455-459, 16 nov., 2016. ilus, tab
Article in Spanish | IBECS | ID: ibc-158106

ABSTRACT

Introducción. Los pacientes con craneosinostosis complejas o unisuturales presentan frecuentemente malformación de Chiari y siringomielia. El tratamiento quirúrgico de la siringomielia en estos pacientes es controvertido. Caso clínico. Niña de 3 años con craneosinostosis compleja no corregida quirúrgicamente. Permaneció asintomática a pesar de que en la resonancia magnética craneal se evidenció una malformación de Chiari y un año después desarrolló una siringomielia cervicodorsolumbar. Se le realizó una craniectomía suboccipital descompresiva, pero posteriormente sufrió un empeoramiento de la siringomielia. El registro de presión intracraneal resultó patológico, por lo que se decidió realizar una craneotomía descompresiva frontoparietotemporal bilateral y remodelación de la bóveda craneal, con lo que se consiguió una disminución significativa de la siringomielia. Conclusiones. Tras la revisión de la bibliografía, se observa que actualmente no existe un consenso sobre el tratamiento de la siringomielia en los pacientes con craneosinostosis y malformación de Chiari. Algunos autores recomiendan la simultánea descompresión quirúrgica suboccipital y de la bóveda craneal, otros sólo la descompresión de la bóveda craneal, y otros la ampliación de la fosa posterior con distractores. En los casos en los que se realizó primero la descompresión suboccipital no se consiguió resolver ni estabilizar la siringomielia. Concluimos que el tratamiento más eficaz para los pacientes con siringomielia y craneosinostosis es la remodelación descompresiva de la bóveda craneal, ya que el principal factor causante de la siringomielia es la hipertensión intracraneal y la falta de distensibilidad del cráneo (AU)


Introduction. Patients with multisutural or single craniosynostosis, often suffer from Chiari malformation and syringomyelia. The surgical management of syringomyelia in these patients is controversial. Case report. A 3-year-old girl was referred with complex craniosynostosis that had not been corrected surgically. She was asymptomatic despite the cranial MRI showed a Chiari malformation and one year later she developed a cervico-dorsolumbar syringomyelia. She underwent a decompressive suboccipital craniectomy but subsequently suffered a worsening of syringomyelia. The intracranial pressure monitoring was pathological so it was decided to perform a decompressive bilateral fronto-parieto-temporal craniotomy and remodeling of the cranial vault, achieving a significant reduction of syringomyelia. Conclusions. After reviewing the literature, it is noted that there is currently no consensus on the treatment of syringomyelia in patients with craniosynostosis and Chiari malformation. Some authors recommend the simultaneous surgical suboccipital and cranial vault decompression, others only decompression of the cranial vault and other enlargement of the posterior fossa with distractors. In cases where the suboccipital decompression was performed first, the syringomyelia was not improved or stabilized. We conclude that the most effective treatment for patients with syringomyelia and craniosynostosis is decompressive remodeling of the cranial vault, as the main cause of syringomyelia is the raised intracranial pressure and lack of skull compliance (AU)


Subject(s)
Humans , Female , Child , Syringomyelia/congenital , Syringomyelia/metabolism , Arnold-Chiari Malformation/complications , Arnold-Chiari Malformation/genetics , Craniosynostoses/genetics , Craniosynostoses/physiopathology , Magnetic Resonance Spectroscopy/methods , Decompressive Craniectomy/methods , Intracranial Hypertension/metabolism , Intracranial Hypertension/pathology , Syringomyelia/complications , Syringomyelia/pathology , Arnold-Chiari Malformation/metabolism , Arnold-Chiari Malformation/pathology , Craniosynostoses/complications , Craniosynostoses/diagnosis , Magnetic Resonance Spectroscopy/standards , Decompressive Craniectomy , Intracranial Hypertension/complications , Intracranial Hypertension/diagnosis
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