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Mölström S, Nielsen TH, Nordström CH, Forsse A, Möller S, Venö S, Mamaev D, Tencer T, Schmidt H, Toft P. Bedside microdialysis for detection of early brain injury after out-of-hospital cardiac arrest. Sci Rep 2021; 11:15871. [PMID: 34354178 PMCID: PMC8342553 DOI: 10.1038/s41598-021-95405-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 07/26/2021] [Indexed: 11/30/2022] Open
Abstract
Bedside detection and early treatment of lasting cerebral ischemia may improve outcome after out-of-hospital cardiac arrest (OHCA). This feasibility study explores the possibilities to use microdialysis (MD) for continuous monitoring of cerebral energy metabolism by analyzing the draining cerebral venous blood. Eighteen comatose patients were continuously monitored with jugular bulb and radial artery (reference) MD following resuscitation. Median time from cardiac arrest to MD was 300 min (IQR 230–390) with median monitoring time 60 h (IQR 40–81). The lactate/pyruvate ratio in cerebral venous blood was increased during the first 20 h after OHCA, and significant differences in time-averaged mean MD metabolites between jugular venous and artery measurements, were documented (p < 0.02). In patients with unfavorable outcome (72%), cerebral venous lactate and pyruvate levels remained elevated during the study period. In conclusion, the study indicates that jugular bulb microdialysis (JBM) is feasible and safe. Biochemical signs of lasting ischemia and mitochondrial dysfunction are frequent and associated with unfavorable outcome. The technique may be used in comatose OHCA patients to monitor biochemical variables reflecting ongoing brain damage and support individualized treatment early after resuscitation.
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Affiliation(s)
- Simon Mölström
- Department of Anesthesiology and Intensive Care, Odense University Hospital, J. B. Winsløws Vej 4, 5000, Odense, Denmark.
| | | | - Carl H Nordström
- Department of Neurosurgery, Odense University Hospital, Odense, Denmark
| | - Axel Forsse
- Department of Neurosurgery, Odense University Hospital, Odense, Denmark
| | - Sören Möller
- OPEN, Open Patient Data Explorative Network, Odense University Hospital, Odense, Denmark.,Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Sören Venö
- Department of Anesthesiology and Intensive Care, Odense University Hospital, J. B. Winsløws Vej 4, 5000, Odense, Denmark
| | - Dmitry Mamaev
- Department of Anesthesiology and Intensive Care, Odense University Hospital, J. B. Winsløws Vej 4, 5000, Odense, Denmark
| | - Tomas Tencer
- Department of Anesthesiology and Intensive Care, Odense University Hospital, J. B. Winsløws Vej 4, 5000, Odense, Denmark
| | - Henrik Schmidt
- Department of Anesthesiology and Intensive Care, Odense University Hospital, J. B. Winsløws Vej 4, 5000, Odense, Denmark
| | - Palle Toft
- Department of Anesthesiology and Intensive Care, Odense University Hospital, J. B. Winsløws Vej 4, 5000, Odense, Denmark
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Mishra P, Jaseja H, Goyal M. A critical analysis of the purported role of hypoxaemia in the comorbidity of obstructive sleep apnoea and epilepsy. Clin Physiol Funct Imaging 2021; 41:4-9. [PMID: 33068455 DOI: 10.1111/cpf.12672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 09/30/2020] [Accepted: 10/13/2020] [Indexed: 02/05/2023]
Abstract
Obstructive sleep apnoea (OSA) is a globally prevalent sleep disorder of significant health concern and confounded with several comorbidities resulting in adverse effect(s) on quality of life in patients afflicted with it. Of particular interest is the enigmatic high comorbidity of OSA with epilepsy, the exact underlying pathophysiology of which remains elusive despite a multitude of research performed in the last four decades. Hypoxaemia, which is an important characteristic feature found in OSA during apnoeic spells, has been implicated in the high comorbidity of OSA with epilepsy, the basis of which rests upon hypoxaemia-mediated brain damage, subcortical release phenomenon, oxidative stress and neuroinflammatory reactions. However, several studies present contradictory evidences that potentially refute the hypoxaemia-based mechanism. Additionally, the role of hypercapnia thatgenerally accompanies hypoxaemia during apnoeic spells, cannot be overlooked and is known to be potentially protective against neuronal hyperexcitability. Thus, hypoxaemia theory implicated in the high comorbidity of OSA and epilepsy appears weak and refutable. This brief paper studies and critically analyses the role of hypoxaemia in conjunction with hypercapnia in the underlying pathophysiology of the comorbidity.
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Affiliation(s)
- Priyadarshini Mishra
- Department of Physiology, All India Institute of Medical Sciences, Bhubaneswar, India
| | | | - Manish Goyal
- Department of Physiology, All India Institute of Medical Sciences, Bhubaneswar, India
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Rasmussen R, O'Donnell J, Ding F, Nedergaard M. Interstitial ions: A key regulator of state-dependent neural activity? Prog Neurobiol 2020; 193:101802. [PMID: 32413398 PMCID: PMC7331944 DOI: 10.1016/j.pneurobio.2020.101802] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 03/24/2020] [Accepted: 03/26/2020] [Indexed: 02/08/2023]
Abstract
Throughout the nervous system, ion gradients drive fundamental processes. Yet, the roles of interstitial ions in brain functioning is largely forgotten. Emerging literature is now revitalizing this area of neuroscience by showing that interstitial cations (K+, Ca2+ and Mg2+) are not static quantities but change dynamically across states such as sleep and locomotion. In turn, these state-dependent changes are capable of sculpting neuronal activity; for example, changing the local interstitial ion composition in the cortex is sufficient for modulating the prevalence of slow-frequency neuronal oscillations, or potentiating the gain of visually evoked responses. Disturbances in interstitial ionic homeostasis may also play a central role in the pathogenesis of central nervous system diseases. For example, impairments in K+ buffering occur in a number of neurodegenerative diseases, and abnormalities in neuronal activity in disease models disappear when interstitial K+ is normalized. Here we provide an overview of the roles of interstitial ions in physiology and pathology. We propose the brain uses interstitial ion signaling as a global mechanism to coordinate its complex activity patterns, and ion homeostasis failure contributes to central nervous system diseases affecting cognitive functions and behavior.
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Affiliation(s)
- Rune Rasmussen
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark.
| | - John O'Donnell
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, United States
| | - Fengfei Ding
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, United States
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark; Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, United States.
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Wong AMC, Yeh CH, Lin JJ, Liu HL, Chou IJ, Lin KL, Wang HS. Arterial spin-labeling perfusion imaging of childhood encephalitis: correlation with seizure and clinical outcome. Neuroradiology 2018; 60:961-970. [PMID: 30046856 DOI: 10.1007/s00234-018-2062-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 07/17/2018] [Indexed: 11/30/2022]
Abstract
PURPOSE In childhood encephalitis, perfusion abnormalities have been infrequently reported to associate with clinical status. We investigated whether perfusion abnormalities correlated with seizure and clinical outcome in encephalitis. METHODS We retrospectively analyzed the MR studies of 77 pediatric patients with encephalitis. Pseudo-continuous arterial spin-labeling (ASL) imaging was performed on a 3-T scanner. The patients were divided into five groups according to ASL perfusion imaging pattern: normal perfusion (NP), focal hypoperfusion (Lf), extreme global hypoperfusion (LE), focal hyperperfusion (Hf), and extreme global hyperperfusion (HE). Clinical outcome at 3 weeks was dichotomized to unfavorable or favorable outcome according to the Glasgow outcome scale. Multivariate logistic regression was conducted to predict unfavorable outcome and presence of seizure separately, based on explanatory variables including age, sex, and ASL pattern. RESULTS Twenty-seven (35%) patients were designated as in group Hf, five (7%) in group Lf, 11 (14%) in group LE, none in group HE, and 34 (44%) in group NP. Multivariate logistic regression analysis showed that ASL pattern was significantly associated with unfavorable outcome (P = 0.005) and with presence of seizure (P = 0.005). For ASL pattern, group LE was 17.31 times as likely to have an unfavorable outcome as group NP (odds ratio confidence interval [CI] 3.084, 97.105; P = 0.001). Group Hf was 6.383 times as likely to have seizure as group NP (CI 1.765, 23.083; P = 0.005). CONCLUSIONS In childhood encephalitis, patients with extreme global hypoperfusion had poor neurological outcome and those with focal hypoperfusion were more likely to have seizure.
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Affiliation(s)
- Alex Mun-Ching Wong
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Keelung/Linkou, and Chang Gung University, 5 Fu-Hsing Street, Taoyuan, 333, Taiwan.
| | - Chih-Hua Yeh
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Keelung/Linkou, and Chang Gung University, 5 Fu-Hsing Street, Taoyuan, 333, Taiwan
| | - Jainn-Jim Lin
- Division of Pediatric Critical Care Medicine, Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Ho-Ling Liu
- Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - I-Jun Chou
- Division of Pediatric Neurology, Department of Pediatrics, Chang Gung Children's Hospital and Chang Gung University, Linkou, Taiwan
| | - Kuang-Lin Lin
- Division of Pediatric Neurology, Department of Pediatrics, Chang Gung Children's Hospital and Chang Gung University, Linkou, Taiwan
| | - Huei-Shyong Wang
- Division of Pediatric Neurology, Department of Pediatrics, Chang Gung Children's Hospital and Chang Gung University, Linkou, Taiwan
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Szabo K, Hirsch JG, Krause M, Ende G, Henn FA, Sartorius A, Gass A. Diffusion weighted MRI in the early phase after electroconvulsive therapy. Neurol Res 2013; 29:256-9. [PMID: 17509223 DOI: 10.1179/174313206x153842] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Although cognitive side effects may occur after electroconvulsive therapy (ECT), no structural brain abnormalities have been detected after ECT with conventional magnetic resonance imaging (MRI). Transient disturbances of memory function are common findings after ECT indicating functional compromise. Diffusion weighted imaging (DWI) has been shown to be sensitive to focal tissue changes associated with compromise of energy metabolism in cerebral ischemia and after prolonged ictal activity. We used conventional MRI and DWI in an exploratory study examining ten patients after treatment with ECT, eight of whom experienced short-lasting memory disturbances. MRI and DWI showed no definite signal abnormalities on qualitative and quantitative analysis. In three patients, equivocal marginal DWI hyperintensity was noted in the hippocampal formation. These findings are in line with previous negative studies using conventional MRI. Higher resolution DWI and serial imaging may be necessary to visualize possible minimal signal changes after ECT.
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Affiliation(s)
- Kristina Szabo
- Department of Neurology, Universitätsklinikum Mannheim, University of Heidelberg, Mannheim, Germany.
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Erdem G, Celik O, Hascalik S, Karakas HM, Alkan A, Firat AK. Diffusion-weighted imaging evaluation of subtle cerebral microstructural changes in intrauterine fetal hydrocephalus. Magn Reson Imaging 2007; 25:1417-22. [PMID: 17513078 DOI: 10.1016/j.mri.2007.03.028] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2006] [Revised: 03/19/2007] [Accepted: 03/21/2007] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Hydrocephalus is an important etiological factor in neurological decline. With the advent of fetal ultrasound, fetal hydrocephalus is now more frequently detected than in the past. Ultrasonography (USG) provides information on general morphology, but microstructural changes that may play a prognostic role are beyond the resolution of that technique. These changes may theoretically be revealed by diffusion-weighted magnetic resonance imaging (DW-MRI). In this study, our preliminary findings of DW-MRI on the hydrocephalic fetuses are presented. MATERIALS AND METHODS Twelve fetuses with fetal USG diagnosis of hydrocephalus were investigated using a 1.5-T MR scanner. In addition to conventional techniques, DWI was performed. It was obtained using a single-shot echo-planar imaging sequence (TR/TE: 4393/81 ms; slice thickness: 5 mm; interslice gap: 1 mm; FOV: 230 mm; matrix size: 128x256; b values: 0 and 1000 s/mm2). Apparent diffusion coefficient (ADC) values were measured in the white matter of the periventricular frontal and occipital lobes, basal ganglia, thalamus, centrum semiovale and cerebrospinal fluid in the lateral ventricle. These values were compared with the normal prenatal ADC values from a radiological study published in the literature. RESULTS All fetuses had moderate or severe bilateral supratentorial ventricular dilatation that was compatible with hydrocephalus. On conventional T1- and T2-weighted imaging, cerebral parenchyma had normal signal pattern and ADC values were significantly lower than those reported for fetuses with normal brain. These values were lower in hydrocephalic fetuses with statistical significance (P<.05-.01). CONCLUSION DWI is a sensitive technique to investigate cerebral microstructure. The reduction in cerebral blood flow and alterations in cerebral energy metabolism in cases with hydrocephalus have been shown before. Changes in cerebral blood flow and energy metabolism, as a consequence of cerebral compression, may occur in hydrocephalus. Elevated ventricular pressure may cause cerebral ischemia. The anaerobic glycolysis seen in the hydrocephalic brain tissue by increasing the lactate concentration and intracellular fluid flux may be the reason for the reduced ADC values in hydrocephalic fetuses. However, long-term prospective trials on the correlation of ADC values and neurological outcome are necessary to exploit the full benefit of that novel technique.
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Affiliation(s)
- Gulnur Erdem
- Department of Radiology, Faculty of Medicine, Inonu University, 44069 Malatya, Turkey.
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Szabo K, Poepel A, Pohlmann-Eden B, Hirsch J, Back T, Sedlaczek O, Hennerici M, Gass A. Diffusion-weighted and perfusion MRI demonstrates parenchymal changes in complex partial status epilepticus. ACTA ACUST UNITED AC 2005; 128:1369-76. [PMID: 15743871 DOI: 10.1093/brain/awh454] [Citation(s) in RCA: 232] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Diffusion-weighted MRI (DWI) and perfusion MRI (PI) have been mainly applied in acute stroke, but may provide information in the peri-ictal phase in epilepsy patients. Both transient reductions of brain water diffusion, namely a low apparent diffusion coefficient (ADC), and signs of hyperperfusion have been reported in experimental and human epilepsy case studies. We studied 10 patients with complex partial status epilepticus (CPSE) with serial MRI including DWI and PI. All patients showed regional hyperintensity on DWI, and a reduction of the ADC in (i) the hippocampal formation and the pulvinar region of the thalamus (six out of 10 patients), (ii) the pulvinar and cortical regions (two out of 10), (iii) the hippocampal formation only (one out of 10), and (iv) the hippocampal formation, the pulvinar and the cortex (one out of 10). In all patients a close spatial correlation of focal hyperperfusion with areas of ADC/DWI change was present. In two patients hyperperfusion was confirmed in additional SPECT (single photon emission computed tomography) studies. All patients received follow-up MRI examinations showing partial or complete resolution of diffusion and perfusion abnormalities depending on the length of the follow-up interval. The clinical course, EEG and SPECT results all indicate that MRI detected changes related to prolonged epileptic activity. Combined PI and DWI can visualize haemodynamic and tissue changes after CPSE in the hippocampus, thalamus and affected cortical regions.
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Affiliation(s)
- Kristina Szabo
- Department of Neurology, Universitätsklinikum Mannheim, University of Heidelberg, Mannheim, Germany
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Patel AB, de Graaf RA, Mason GF, Kanamatsu T, Rothman DL, Shulman RG, Behar KL. Glutamatergic neurotransmission and neuronal glucose oxidation are coupled during intense neuronal activation. J Cereb Blood Flow Metab 2004; 24:972-85. [PMID: 15356418 DOI: 10.1097/01.wcb.0000126234.16188.71] [Citation(s) in RCA: 126] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
13C nuclear magnetic resonance (NMR) experiments have previously shown that glutamatergic neurotransmitter flux (Vcycle(Glu/Gln)) changes proportionately with neuronal glucose oxidation (CMRglc(ox)N) in the nonactivated cortex of anesthetized rats. Positron Emission Tomography measurements of glucose and oxygen uptake during sensory stimulation had shown that the incremental glucose utilization is greater than oxygen leading to the suggestion that the energy required for stimulated neuronal activity arises from nonoxidative glucose metabolism. In this study, the authors used spatially localized 1H-observed, 13C-edited NMR spectroscopy during an infusion of [1,6-13C2]glucose to assess the relationship between changes in Vcycle(Glu/Gln) and glucose utilization (CMRglc(ox)N and CMRglc(nonox)) during the intense cortical activity associated with bicuculline-induced seizures. Metabolic fluxes were determined by model-based analysis of the 13C-enrichment time courses of glutamate-C4 and glutamine-C4 (CMRglc(ox)N, Vcycle(Glu/Gln)) and lactate-C3 (CMRglc(nonox)). The exchange rate between alpha-ketoglutarate and glutamate was found to be significantly faster than TCA cycle flux both for control (41 micromol.g(-1).min(-1); 95% CI, 5 to 109 micromol.g(-1).min(-1)) and during seizures (21 micromol.g(-1).min(-1); 95% CI, 4.4 to 51.8 micromol.g(-1).min(-1)). During seizures, total glucose utilization (CMRglc(ox+nonox)) increased substantially (466% between 0 and 6 minutes; 277% between 6 and 55 minutes). Glucose oxidation (CMRglc(ox)N) also increased (214%; from 0.26 +/- 0.02 to 0.57 +/- 0.07 micromol.g(-1).min(-1)) but to a lesser degree, resulting in a large increase in cortical lactate concentration. Vcycle(Glu/Gln) increased 233% (from 0.22 +/- 0.04 to 0.52 +/- 0.07 micromol.g(-1).min(-1)), which was similar to the increase in glucose oxidation. The value of Vcycle(Glu/Gln) and CMRglc(ox)N obtained here lie on the line predicted in a previous study. These results indicate that neuronal glucose oxidation and not total glucose utilization is coupled to the glutamate/glutamine cycle during intense cortical activation.
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Affiliation(s)
- Anant B Patel
- Department of Psychiatry, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
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Gass A, Niendorf T, Hirsch JG. Acute and chronic changes of the apparent diffusion coefficient in neurological disorders--biophysical mechanisms and possible underlying histopathology. J Neurol Sci 2001; 186 Suppl 1:S15-23. [PMID: 11334986 DOI: 10.1016/s0022-510x(01)00487-7] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Diffusion-weighted imaging (DWI) of the brain has become a valuable tool for the reliable detection and diagnosis of several neurological disorders. Although DWI is in wide use in daily practice, the underlying biophysical mechanisms that contribute to changes in the apparent diffusion coefficient (ADC) are still under discussion. Alterations in the apparent water diffusion rate reflect pathological changes in the brain tissue state, via changes in the diffusion characteristics of the intra- and extra-cellular water compartments including restricted diffusion, water exchange across permeable boundaries, the concept of the extra-cellular tortuosity and the intra- and extra-cellular volume fraction. A reduction of the ADC has been detected in acute neurological diseases, while disease states associated with dominant acute vasogenic edema formation or chronic tissue destruction usually show elevations of the ADC. Compromise of energy metabolism is likely to contribute to a reduction of the ADC while already minor structural disintegration may contribute to elevations of the ADC.
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Affiliation(s)
- A Gass
- NMR Research Neurology/Radiology, Klinikum Mannheim, University of Heidelberg, Theodor Kutzer Ufer, 68137 Mannheim, Germany.
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Sasahira M, Simon RP, Greenberg DA. Neuronal injury in experimental status epilepticus in the rat: role of hypoxia. Neurosci Lett 1997; 222:207-9. [PMID: 9148251 DOI: 10.1016/s0304-3940(97)13378-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
While it seems axiomatic that hypoxia is a risk factor for neuronal death during prolonged seizures, the classic neuropathologic literature does not confirm such an association. We investigated this issue by inducing status epilepticus in normoxic (PaO2 approximately 100 mmHg) and hypoxia (PaO2 approximately 50 mmHg) rats, using heat-shock protein (HSP) expression as an index of early cell injury and acid fuchsin staining to detect cell death. Neither stress protein induction nor neuronal death was increased in the selectively vulnerable CA3c region of hippocampus, or in cerebral cortex, of hypoxic compared to normoxic animals. These data support the concept that moderate hypoxia is not a risk factor for brain injury from status epilepticus.
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Affiliation(s)
- M Sasahira
- Department of Neurology, University of Pittsburgh School of Medicine, PA 15213, USA
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Kofke WA, Garman RH, Janosky J, Rose ME. Opioid neurotoxicity: neuropathologic effects in rats of different fentanyl congeners and the effects of hexamethonium-induced normotension. Anesth Analg 1996; 83:141-6. [PMID: 8659725 DOI: 10.1097/00000539-199607000-00025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We tested the hypotheses that convulsant doses of opioids would produce limbic system damage exacerbated by hexamethonium. Ventilated paralyzed rats received intravenous (IV) isovolumic infusion of fentanyl loading dose (LD) 1000 micrograms/kg, maintenance dose (MD) 40 micrograms.kg-1.min-1 (n = 10), sufentanil LD 400 micrograms/kg, MD 13.3 micrograms.kg-1.min-1 (n = 10), alfentanil LD 1500 micrograms/kg, MD 150 micrograms.kg-1.min-1 (n = 10), or 0.9% saline control LD 4 mliter/kg, MD 4 mliter.kg-1.h-1 (n = 10), with O2/N2 30%/70% during opioid infusion and O2/N2O in controls during saline infusion. Hexamethonium (LD 20 mg/kg, MD 40-120 mg.kg-1.h-1) was given IV during opioid infusion to half of the rats. Cerebral perfusion-fixation with formalin was performed 24 h later, followed by histopathologic assessment. None of the control rats showed any histologic abnormalities. Overall summed neuropathologic severity was worse in opioid treated groups (P = 0.01). Lesions occurred primarily in cortical regions and limbic system structures. When arterial blood pressure was controlled to a lower level with hexamethonium (147 vs 100 mm Hg), rats had less severe lesions (P = 0.02). These data indicate that fentanyl, sufentanil, and alfentanil all can produce histopathologic evidence of brain injury in rats mitigated by hexamethonium.
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Affiliation(s)
- W A Kofke
- Department of Anesthesiology and Critical Care Medicine, University of Pittsburgh School of Medicine, Pennsylvania, USA.
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Lawrence MS, Ho DY, Dash R, Sapolsky RM. Herpes simplex virus vectors overexpressing the glucose transporter gene protect against seizure-induced neuron loss. Proc Natl Acad Sci U S A 1995; 92:7247-51. [PMID: 7638175 PMCID: PMC41316 DOI: 10.1073/pnas.92.16.7247] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
We have generated herpes simplex virus (HSV) vectors vIE1GT and v alpha 4GT bearing the GLUT-1 isoform of the rat brain glucose transporter (GT) under the control of the human cytomegalovirus ie1 and HSV alpha 4 promoters, respectively. We previously reported that such vectors enhance glucose uptake in hippocampal cultures and the hippocampus. In this study we demonstrate that such vectors can maintain neuronal metabolism and reduce the extent of neuron loss in cultures after a period of hypoglycemia. Microinfusion of GT vectors into the rat hippocampus also reduces kainic acid-induced seizure damage in the CA3 cell field. Furthermore, delivery of the vector even after onset of the seizure is protective, suggesting that HSV-mediated gene transfer for neuroprotection need not be carried out in anticipation of neurologic crises. Using the bicistronic vector v alpha 22 beta gal alpha 4GT, which coexpresses both GT and the Escherichia coli lacZ marker gene, we further demonstrate an inverse correlation between the extent of vector expression in the dentate and the amount of CA3 damage resulting from the simultaneous delivery of kainic acid.
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Affiliation(s)
- M S Lawrence
- Department of Biological Sciences, Stanford University, CA 94305, USA
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Visioli F, Rihn LL, Rodriguez de Turco EB, Kreisman NR, Bazan NG. Free fatty acid and diacylglycerol accumulation in the rat brain during recurrent seizures is related to cortical oxygenation. J Neurochem 1993; 61:1835-42. [PMID: 8228997 DOI: 10.1111/j.1471-4159.1993.tb09824.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Cerebral blood flow and oxygenation increase during the early seizures of a series, but the increase in cerebral blood flow attenuates during late seizures, sometimes resulting in decreased cortical oxygenation. Cortical free fatty acids (FFA) and diacylglycerols also increase during early seizures and the increase attenuates during late seizures. We analyzed the correlation between lipid accumulation and cortical O2 during periodic pentylenetetrazol-induced seizures. During early seizures, both FFA and diacylglycerols increased in the cerebral cortex, particularly arachidonate (20:4) and stearate (18:0). Changes in lipids were different during late seizures, depending on cortical O2 levels. An increase in cortical O2 during late seizures was associated with lower FFA levels compared with early seizures, and FFA levels recovered to basal levels during interictal periods. A decline in cortical O2 was associated with a further increase in FFA, which remained elevated during interictal periods. Our results indicate that periseizure lipid accumulation is related to cortical oxygenation.
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Affiliation(s)
- F Visioli
- LSU Eye Center and Neuroscience Center, New Orleans 70112
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Kloiber O, Bockhorst K, Hoehn-Berlage M, Hossmann KA. Effect of hypoxia on bicuculline seizures of rat: NMR spectroscopy and bioluminescence imaging. NMR IN BIOMEDICINE 1993; 6:333-338. [PMID: 8268066 DOI: 10.1002/nbm.1940060509] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Previous studies suggested that hypoxia reduces the severity of brain injury after epileptic seizures. To test this hypothesis, the effect of hypoxic arrest of epileptic seizures on brain metabolism was investigated in rats by combining in vivo NMR spectroscopy with imaging techniques for the pictorial evaluation of energy metabolism and pH. Seizures were produced by i.v. injection of bicuculline, and measurements were compared in animals with and without 5 min exposure to 5% oxygen after the onset of seizures. Transient hypoxia persistently reduced seizure activity, even after return to normoxia. Hypoxia or seizure alone had little effect on brain metabolism but the combination of both led to marked albeit reversible deterioration of energy and acid/base status. In normoxic animals pictorial measurements of energy state 2 h after the onset of seizures revealed a regional decline of ATP in the hippocampus. In animals in which seizures were arrested by transient hypoxia ATP depletion was additionally observed in the border zones of vascular territories. These results demonstrate that hypoxic arrest of seizure activity leads to the aggravation of metabolic disturbances and is therefore not suited to preventing permanent brain injury.
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Affiliation(s)
- O Kloiber
- Max-Planck-Institute for Neurological Research, Department of Experimental Neurology, Cologne, Germany
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Freund TF, Ylinen A, Miettinen R, Pitkänen A, Lahtinen H, Baimbridge KG, Riekkinen PJ. Pattern of neuronal death in the rat hippocampus after status epilepticus. Relationship to calcium binding protein content and ischemic vulnerability. Brain Res Bull 1992; 28:27-38. [PMID: 1347249 DOI: 10.1016/0361-9230(92)90227-o] [Citation(s) in RCA: 151] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The pattern of hippocampal cell death has been studied following hippocampal seizure activity and status epilepticus induced by 110-min stimulation of the perforant pathway in awake rats. The order of vulnerability of principal cells in the different hippocampal subfields--as determined by silver impregnation--was found to be very similar to the pattern found in ischemia; i.e., dentate hilus greater than CA1, subiculum greater than CA3c greater than CA3a,b greater than dentate granule cells. The hilar somatostatin-containing cells were the most vulnerable cell type, whereas all other subpopulations of nonprincipal neurons--visualized by immunocytochemistry for the calcium binding proteins parvalbumin and calbindin--were remarkably resistant. Pyramidal cells in the CA3 region containing neither of the examined calcium binding proteins were more resistant to overexcitation than CA1 pyramidal cells, most of which do contain calbindin. This indicates that no simple relationship exists between vulnerability in status epilepticus and neuronal calcium binding protein content, and that local and/or systemic hypoxia during status epilepticus may be responsible for the ischemic pattern of cell death.
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Affiliation(s)
- T F Freund
- Department of Functional Neuroanatomy, Hungarian Academy of Sciences, Budapest
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Kreisman NR, Magee JC, Brizzee BL. Relative hypoperfusion in rat cerebral cortex during recurrent seizures. J Cereb Blood Flow Metab 1991; 11:77-87. [PMID: 1845766 DOI: 10.1038/jcbfm.1991.9] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Focal cortical CBF and oxygenation were measured in rats during repetitive seizures to determine whether CBF is maintained above a critical level for adequate delivery of O2. Cerebral oxygenation was determined by measuring relative changes in the oxidation/reduction level of cytochrome aa3 and CBF was measured by the washout of H2. During early seizures, cortical CBF increased to 350% of control and cortical oxygenation also rose markedly. During later seizures, both the increases in CBF and in cortical oxygenation were attenuated progressively. This was accompanied also by attenuation of the associated increases in MABP. Cortical oxygenation decreased during a seizure if the increase in CBF failed to exceed 150-200% of control, defining the critical CBF value. Ventilating the rats on 97% O2 resulted in restoration of the seizure-associated increases in cortical oxygenation in 50% of the cases. The elevation of inspired O2 was effective only if CBF increased once again above 150-200% of control, confirming that the critical CBF lies within this range of values. We conclude that CBF must rise greater than 200% of control levels to provide sufficient O2 to meet the enhanced metabolic requirements of repetitive seizures.
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Affiliation(s)
- N R Kreisman
- Department of Physiology, Tulane University School of Medicine, New Orleans, Louisiana 70112
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Sapolsky RM, Stein BA. Status epilepticus-induced hippocampal damage is modulated by glucose availability. Neurosci Lett 1989; 97:157-62. [PMID: 2919000 DOI: 10.1016/0304-3940(89)90156-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Kainic acid administration induces status epilepticus seizures in the rat which damage CA1 and CA3 hippocampal neurons. Rats made hypoglycemic prior to seizure had enhanced volumes of damage, when compared to normo- or hyperglycemic rats. The mild hypoglycemia was not in the range which, itself, typically produces hippocampal damage. This suggests that limited energy availability compromised the ability of neurons to survive seizures. Our data also suggest that the CA1 damage seen after status epilepticus is not hypoxic-ischemic in origin, since elevating pre-seizure glucose concentrations to a range which typically exacerbates hypoxic-ischemic CA1 damage did not augment status-epilepticus CA1 damage.
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Affiliation(s)
- R M Sapolsky
- Department of Biological Sciences, Stanford University, CA 94305
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Oberpichler H, Beck T, Abdel-Rahman MM, Bielenberg GW, Krieglstein J. Effects of Ginkgo biloba constituents related to protection against brain damage caused by hypoxia. PHARMACOLOGICAL RESEARCH COMMUNICATIONS 1988; 20:349-68. [PMID: 3420139 DOI: 10.1016/s0031-6989(88)80011-0] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The purpose of the present study was to approach the compound(s) responsible for the beneficial effects of an extract of Ginkgo biloba leaves (EGB) on animals subjected to hypoxia. In this first approach we compared the effects of the flavone and the non-flavone fraction of EGB with those of the whole extract on mice in lethal hypoxia (3.5% O2), on brain energy metabolism of artificially ventilated rats inspiring 7% O2, and on local cerebral blood flow (LCBF) of normoxic rats. The latter two experimental settings should also extend the knowledge about the underlying mechanisms of the antihypoxidotic actions. EGB as well as its non-flavone fraction considerably prolonged the survival time of mice under lethal hypoxia. EGB retarded the breakdown of brain energy metabolism in the hypoxic artificially ventilated rat. A corresponding effect was exerted by the non-flavone fraction while the flavone fraction even worsened the metabolic state. The non-flavone fraction increased LCBF in the majority of 35 examined brain regions; a similar effect could be seen after EGB-treatment, while the flavone fraction caused only minor alterations of LCBF. We conclude that the non-flavone fraction of EGB carries the antihypoxidotic activity. Metabolic effects are suggested to cause this activity. Further studies are necessary to elucidate the effective compound within this fraction.
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Affiliation(s)
- H Oberpichler
- Institut für Pharmakologie und Toxikologie, Philipps-Universität, Marburg, Fed. Rep. of Germany
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