Nervous system epilepsy

People who should not work with organophosphate insecticides are those with organic central nervous system disease, mental disorders, epilepsy, pronounced endocrine disorders, respiratory conditions, cardiovascular diseases, circulatory disorders, gastroenteric diseases, liver or kidney disease, and chronic conjunctivitis and keratitis (Medved and Kagan 1983). 

The central nervous system is a major target of endosulfan-induced toxicity in both humans and animals (Blanco-Coronado et al. 1992 Boyd and Dobos 1969 Boyd et al. 1970 Garg et al. 1980 Kiran and Varma 1988 Terziev et al. 1974). Therefore, individuals with seizure disorders, such as epilepsy, may be particularly susceptible because exposure to endosulfan may reduce the threshold for tremors, seizures, and other forms of neurotoxicity, as demonstrated in studies in rats (Gilbert and Mack 1995 Gilbert 1992). 

For nearly 80% of patients with epilepsy, the underlying etiology is unknown.8 The most common recognized causes of epilepsy are head trauma and stroke. Developmental and genetic defects are the cause of about 5% of cases of epilepsy. Central nervous system (CNS) tumors, central nervous system infections, and neurodegen-erative diseases are other common causes. Other important causes of epilepsy are human immunodeficiency virus infection or neuro-cysticercosis infection, primarily occurring in Latin America. 

Isolated seizures that are not epilepsy can be caused by stroke, central nervous system trauma, central nervous system infections, metabolic disturbances (e.g., hyponatremia and hypoglycemia), and hypoxia. If these underlying causes of seizures are not corrected, they may lead to the development of recurrent seizures I or epilepsy. Medications can also cause seizures. Some drugs that are commonly associated with seizures include tramadol, bupropion, theophylline, some antidepressants, some antipsy-chotics, amphetamines, cocaine, imipenem, lithium, excessive doses of penicillins or cephalosporins, and sympathomimetics or stimulants. 

Signs and Symptoms Symptoms include sudden onset of intense headache, fever, nausea, vomiting, and sensitivity to light (photophobia) followed by central nervous system abnormalities such as stupor, tremors, delirium, focal epilepsy and flaccid paralysis (especially in the shoulder), and coma. Recovery is prolonged. Sequelae may include paralysis of the upper extremities and back. 

A broad variety of diseases may cause neuropathic pain. The majority of diseases associated with neuropathic pain involve the peripheral nervous system. These diseases include traumatic injuries hereditary, metabolic, inflammatory or paraneoplastic neuropathies and infections. However, neuropathic pain can also be caused by injuries or disorders affecting the spinal cord or the brain (central neuropathic pain) tumors stroke epilepsy and neurodegenerative disorders [20]. Genetic factors appear to contribute to inter-individual differences in the susceptibility to neuropathic pain. 

Zinc is important to the normal functioning of the central nervous system (CNS). At low concentrations, zinc protects mammalian brain neurons by blocking N-methyl-D-aspartate receptor-mediated toxicity. At high concentrations, zinc is a potent, rapidly acting neurotoxicant in the mammalian brain, as judged by zinc-induced neuronal injury of in vitro mature cortical cell cultures (Choi et al. 1988). Increased brain levels of zinc are associated with Pick s disease in certain strains of rodents with inherited epileptic seizures. Intravenous injection of zinc in rats with genetically inherited epilepsy produces seizures a similar response occurs with intracranial injection of zinc in rabbits with inherited audiogenic seizures (Choi et al. 1988). 

Ionotropic glutamate receptors mediate fast excitatory neurotransmission in practically all areas of the central nervous system (CNS). They are also critical for both the induction and expression of synaptic plasticity, and have been implicated in diverse pathological conditions, such as epilepsy, ischemic brain damage, anxiety, and addiction. There are three subtypes of ionotropic glutamate receptors that are named after their high-affinity agonists as a-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA), N-1nethyl-D-aspartate (NMDA), and kainate (KA) receptors (1). 

Glutamate that is a major neurotransmitter in the mammalian nervous system not only plays a role in the development of the brain and learning but is also a potent neurotoxin when present in excess at synapses (Plaitakis and Shashidharan, 2000 Rausch et ah, 2006). Glutamate excitotoxicity has been shown to contribute to neuronal degeneration in acute conditions such as stroke, epilepsy, h) oglycemia, and chronic... 

Epilepsy is a chronic often progressive disorder of the central nervous system (CNS). Periodic and unpredictable epileptic seizures caused by the abnormal electrical discharge of neurones in various anatomic structures of the CNS is the characteristic feature. This is an approximate definition based on international classifications of seizures and syndromes which take into account the extremely variable clinical and electroencephalographic expression of the disease. The annual incidence of epilepsy is an estimated 20-70 cases per 100,000 inhabitants with a prevalence of 0.4-0.8%. Globally, incidence is higher during childhood, remaining rather stable... 

Nearly all central nervous system depressants have some capacity to suppress seizures by virtue of their depressant activity on the brain and spinal cord. Clonazepam and diazepam are two benzodiazepines that depress epileptiform activity and are used in the treatment of epilepsy and seizure disorders (see Chapter 32). 

Epilepsy is an example of excessive neural signaling in the central nervous system. Relative cellular and extracellular space (ECS) volume has been demonstrated to play an important role in the propensity for epileptic seizures. For example, reducing ECS volume by exposure to hypotonic medium produces hyperexcitability and enhanced epileptiform activity, whereas hyperosmolar medium reduces excitability. The hypothesis that AQP4-dependent water transport in astrocytes might modulate intrinsic brain excitability was tested by seizure susceptibility in response to the GABAa antagonist convulsant pentylenetetrazol... 

Complexity of inhibition of PLP-dependent enzymes is highlighted by detailed investigations on the inhibition of y-aminobutyric acid aminotransferase (GABA-AT), the enzyme responsible for the degradation of y-aminobutyric acid (GABA), one of the major inhibitory neurotransmitters in the mammalian central nervous system. Inhibition of GAB A-AT results in an increased concentration of GABA in the brain and could have therapeutic applications in neurological disorders (epilepsy, Parkinson disease, and Alzheimer disease). 

Lapierre YD, Browne M, Horn E, et al Treatment of major affective disorder with fluvoxamine. J Clin Psychiatry 48 65-68, 1987 Lapierre YD, Ravindran AV, Bakish D Dysthymia and serotonin. Int Clin Psychopharmacol 8 (suppl 2) 87-90, 1993 Lapin 1, Oxenkrug G Intensification of the central serotonergic process as a possible determinant of thymoleptic effect. Lancet 1 132-136, 1969 Larkin JG, McKee PJ, Blacklaw J, et al Nimodipine in refractory epilepsy a placebo-controlled, add-on study. Epilepsy Res 9 71-77, 1991 Larsson LI, Rehfeld JF Localization and molecular heterogeneity of cholecystokinin in the central and peripheral nervous system. Brain Res 165 201-218, 1979 Laruelle M, Abi-Dargham A, Casanova M, et al Selective abnormality of prefrontal serotonergic receptors in schizophrenia a post mortem study. Arch Gen Psychiatry 50 810-818, 1993... 

Nervous system (dementia, stroke, epilepsy, extrapyramidal diseases [Parkinson s], demyelinating diseases [multiple sclerosis], neuropathy, myasthenia gravis, psychosis, schizophrenia)... 

It is a benzodiazepine useful in the treatment of petitmal epilepsy, myoclonic seizures and infantile spasms. It is used in the treatment of petitmal epilepsy not responding to ethosuximide and sodium valproate. Clonazepam and diazepam act by increasing the effectiveness of the inhibitory neurotransmitter GABA, within the central nervous system. 

More important than numerical data are the clinical implications of differences between the two countries. The largest differences have narrowed since the previous study, but important categories in which the U.S. still lagged behind Britain in December 1976 included cardiovascular drugs, peptic ulcer treatment, and central nervous system drugs—including therapies for depression, epilepsy, and migraine. 

Most cells of the immune system are ordinarily kept apart from those of the nervous system by means of the blood-brain barrier. However, allergic encephalomyelitis, in which T cells attack the myelin sheath of brain neurons, can easily be induced in mice.506 A similar autoimmune process is thought to be involved in human multiple sclerosis (see Chapter 30, pp. 1769, 1808, and Fig. 30-9).507,508 High levels of circulating IgM are found in some demyelinating diseases of peripheral neurons.508 In Rasmussen s encephalitis, which causes brain inflammation and epilepsy, serum antibodies attack a glutamate receptor subunit GluR3.509... 

Latini S, Pedata F (2001) Adenosine in the central nervous system release mechanisms and extracellular concentrations. J Neurochem 79(3) 463 184 Laudadio MA, Psarropoulou C (2004) The A3 adenosine receptor agonist 2-C1-IB-MECA facilitates epileptiform discharges in the CA3 area of immature rat hippocampal slices. Epilepsy Res 59(2—3) 83—94... 

Barbiturates are among the drugs classified as central nervous system (CNS) depressants. These drugs depress or slow down the activity of nerves that control emotions and bodily functions such as breathing. Barbiturates are prescribed as a sedative that calms the patient or as a hypnotic that helps a person sleep. Other uses include epilepsy treatment and anesthesia before surgery. 

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