Cerebral edema is excess accumulation of fluid (edema) in the intracellular or extracellular spaces of the brain. This typically causes impaired nerve function, increased pressure within the skull, and can eventually lead to direct compression of brain tissue and blood vessels. Symptoms vary based on the location and extent of edema and generally include headaches, nausea, vomiting, seizures, drowsiness, visual disturbances, dizziness, and in severe cases, death.
Cerebral hypoxia is a form of hypoxia, specifically involving the brain; when the brain is completely deprived of oxygen, it is called cerebral anoxia. There are four categories of cerebral hypoxia; they are, in order of increasing severity: diffuse cerebral hypoxia (DCH), focal cerebral ischemia, cerebral infarction, and global cerebral ischemia. Prolonged hypoxia induces neuronal cell death via apoptosis, resulting in a hypoxic brain injury.
Neuroprotection refers to the relative preservation of neuronal structure and/or function. In the case of an ongoing insult the relative preservation of neuronal integrity implies a reduction in the rate of neuronal loss over time, which can be expressed as a differential equation. It is a widely explored treatment option for many central nervous system (CNS) disorders including neurodegenerative diseases, stroke, traumatic brain injury, spinal cord injury, and acute management of neurotoxin consumption. Neuroprotection aims to prevent or slow disease progression and secondary injuries by halting or at least slowing the loss of neurons. Despite differences in symptoms or injuries associated with CNS disorders, many of the mechanisms behind neurodegeneration are the same. Common mechanisms of neuronal injury include decreased delivery of oxygen and glucose to the brain, energy failure, increased levels in oxidative stress, mitochondrial dysfunction, excitotoxicity, inflammatory changes, iron accumulation, and protein aggregation. Of these mechanisms, neuroprotective treatments often target oxidative stress and excitotoxicity—both of which are highly associated with CNS disorders. Not only can oxidative stress and excitotoxicity trigger neuron cell death but when combined they have synergistic effects that cause even more degradation than on their own. Thus limiting excitotoxicity and oxidative stress is a very important aspect of neuroprotection. Common neuroprotective treatments are glutamate antagonists and antioxidants, which aim to limit excitotoxicity and oxidative stress respectively.
Excitatory amino acid transporter 1 (EAAT1) is a protein that, in humans, is encoded by the SLC1A3 gene. EAAT1 is also often called the GLutamate ASpartate Transporter 1 (GLAST-1).
Citicoline (INN), also known as cytidine diphosphate-choline (CDP-Choline) or cytidine 5'-diphosphocholine is an intermediate in the generation of phosphatidylcholine from choline, a common biochemical process in cell membranes. Citicoline is naturally occurring in the cells of human and animal tissue, in particular the organs.
SCH-58261 is a drug which acts as a potent and selective antagonist for the adenosine receptor A2A, with more than 50x selectivity for A2A over other adenosine receptors. It has been used to investigate the mechanism of action of caffeine, which is a mixed A1 / A2A antagonist, and has shown that the A2A receptor is primarily responsible for the stimulant and ergogenic effects of caffeine, but blockade of both A1 and A2A receptors is required to accurately replicate caffeine's effects in animals. SCH-58261 has also shown antidepressant, nootropic and neuroprotective effects in a variety of animal models, and has been investigated as a possible treatment for Parkinson's disease.
Metabotropic glutamate receptor 7 is a protein that in humans is encoded by the GRM7 gene.
Brain mitochondrial carrier protein 1 is a protein that in humans is encoded by the SLC25A14 gene.
Dejerine–Roussy syndrome or thalamic pain syndrome is a condition developed after a thalamic stroke, a stroke causing damage to the thalamus. Ischemic strokes and hemorrhagic strokes can cause lesioning in the thalamus. As initial stroke symptoms dissipate, an imbalance in sensation causes these later syndromes, characterizing Dejerine–Roussy syndrome. Although some treatments exist, they are often expensive, chemically based, invasive, and only treat patients for some time before they need more treatment, called "refractory treatment".
In pathology and anatomy the penumbra is the area surrounding an ischemic event such as thrombotic or embolic stroke. Immediately following the event, blood flow and therefore oxygen transport is reduced locally, leading to hypoxia of the cells near the location of the original insult. This can lead to hypoxic cell death (infarction) and amplify the original damage from the ischemia; however, the penumbra area may remain viable for several hours after an ischemic event due to the collateral arteries that supply the penumbral zone.
Taltirelin is a thyrotropin-releasing hormone (TRH) analog, which mimics the physiological actions of TRH, but with a much longer half-life and duration of effects, and little development of tolerance following prolonged dosing. It has nootropic, neuroprotective and analgesic effects.
Sarpogrelate is a drug which acts as an antagonist at the 5HT2A and 5-HT2B receptors. It blocks serotonin-induced platelet aggregation, and has applications in the treatment of many diseases including diabetes mellitus, Buerger's disease, Raynaud's disease, coronary artery disease, angina pectoris, and atherosclerosis.
Indeloxazine (INN) is an antidepressant and cerebral activator that was marketed in Japan and South Korea by Yamanouchi Pharmaceutical Co., Ltd for the treatment of psychiatric symptoms associated with cerebrovascular diseases, namely depression resulting from stroke, emotional disturbance, and avolition. It was marketed from 1988 to 1998, when it was removed from the market reportedly for lack of effectiveness.
Mild total body hypothermia, induced by cooling a baby to 33-34°C for three days after birth, is nowadays a standardized treatment after moderate to severe hypoxic ischemic encephalopathy in full-term and near to fullterm neonates. It has recently been proven to be the only medical intervention which reduces brain damage, and improves an infant's chance of survival and reduced disability.
Repinotan (BAYx3702), an aminomethylchroman derivative, is a selective 5-HT1A receptor full agonist with high potency and efficacy. It has neuroprotective effects in animal studies, and was trialed in humans for reducing brain injury following head trauma. It was subsequently trialed up to phase II for treatment of stroke, but while side effects were mild and consisted mainly of nausea, repinotan failed to demonstrate sufficient efficacy to justify further clinical trials. However, repinotan continues to be investigated for other applications, and was found to be effective at counteracting the respiratory depression produced by morphine, though with slight reduction in analgesic effects.
Grinker's myelinopathy, also known as anoxic leukoencephalopathy, is a rare disease of the central nervous system. The disease is characterized by a delayed leukoencephalopathy after a hypoxic episode. It is typically, though not necessarily, related to carbon monoxide poisoning or heroin overdose. It occurs in roughly 2.8% of those who experience an acute hypoxic/anoxic episode. Because of the wide range of symptoms and the delay in onset, it is often misdiagnosed as other neuropathologies. Grinker's myelinopathy was originally characterized by Roy R. Grinker in 1925 or 1926, depending on the source.
Teniloxazine, also known as sufoxazine and sulfoxazine, is a drug which is marketed in Japan. Though initially investigated as a neuroprotective and nootropic agent for the treatment of cerebrovascular insufficiency in the 1980s, it was ultimately developed and approved as an antidepressant instead. It acts as a potent norepinephrine reuptake inhibitor, with fair selectivity over the serotonin and dopamine transporters, and also behaves as an antagonist of the 5-HT2A receptor.
Erythropoietin in neuroprotection is the use of the glycoprotein erythropoietin (Epo) for neuroprotection. Epo controls erythropoiesis, or red blood cell production.
Anoxic depolarization is a progressive and uncontrollable depolarization of neurons during stroke or brain ischemia in which there is an inadequate supply of blood to the brain. Anoxic depolarization is induced by the loss of neuronal selective membrane permeability and the ion gradients across the membrane that are needed to support neuronal activity. Normally, the Na+/K+-ATPase pump maintains the transmembrane gradients of K+ and Na+ ions, but with anoxic brain injury, the supply of energy to drive this pump is lost. The hallmarks of anoxic depolarization are increased concentrations of extracellular K+ ions, intracellular Na+ and Ca2+ ions, and extracellular glutamate and aspartate. Glutamate and aspartate are normally present as the brain's primary excitatory neurotransmitters, but high concentrations activate a number of downstream apoptotic and necrotic pathways. This results in neuronal dysfunction and brain death.
A cerebroprotectant is a drug that is intended to protect the brain after the onset of acute ischemic stroke. As stroke is the second largest cause of death worldwide and a leading cause of adult disability, over 150 drugs tested in clinical trials to provide cerebroprotection.
