The Abnormal Excitation of a Group of Neurons - Essay Example

Seizures Normally neurons work in a synchronized and organized way. In situations, these neurons become hyperactive in an abnormal way and as a result affect all the parts of the body innervated by them. In fact, seizures is the name given to the abnormal excitation of a group of neurons, which results in abnormal synchronization of the electrical activity of nervous system. In turn, this abnormal neuronal activity influences all the anatomical structures and physiological functions controlled by the abnormally hyperactive group of neurons in the brain. These changes, eventually, reflect as bizarre muscular movements, fits, altered level of mental status, even some individuals may exhibit psychic symptoms. Seizures are temporary phenomena; some individuals have got repeated episodes of seizures. These repeated episodes have been given a medical name of epilepsy. Individuals with seizures may present in different ways depending upon the level of and number of neurons involved. In a number of individuals, it is just a jerky movement involving one or more limbs or other areas with conscious level maintained while in others the movements may involve whole body and individual may loose her/his consciousness. So, seizures have been classified according to the level of complexity and consciousness. When some parts of the body are involved, seizures are called as partial otherwise they are generalized. If consciousness is lost which usually occurs with generalized seizures then these are called complex, if consciousness is present, these are simple seizures. Generalized seizures may affect body in a variety of ways and they have been further divided based on the types of movements they are producing: absence, myoclonic, clonic and atonic seizures. In contrast, there are some situations in which these seizures may be single, for example: trauma or head injury, high grade fever especially in children, a symptom of other diseases including tumor and reactions to some drugs. At times, a partial seizure may spread in the brain when it is called secondary generalization. A persistent state of seizures for more than 5 minutes or by other doctors for 30 minutes is called status epilepticus. It is a real emergency state, which needs urgent measures to bring the patient out of the condition (Wikipedia, Carpenter ch:125). Current Treatment Treatment is required when seizures become recurrent. If the cause of the seizure is removed then there is no need of use of epileptic drugs; this occurs in situations like febrile conditions in children or seizures due to electrolytes imbalance. Main purpose of these drugs is to stop seizures because in addition to the direct effects of seizures there are chances of more severe complications, for example accidents resulting from seizures while driving, to arise if these seizures are not treated effectively. The criteria for starting anti-epileptic drugs are: evidence of focal neurological lesion based on clinical examination, radiological findings or EEG interpretations. If seizures occur once and there are no other findings especially in adults then there is no need of epileptic drugs. These drugs have been classified and prioritised for various types of seizures: Partial - simple and complex: carbamazepin,phenytoin, valproate, gabapentin, lamotrigine, topiramate Secondary generalized: carbamazepin, phenytoin, valproate, gabapentin, lamotrigine, topiramate Primary Generalized - absence: ethosuximide, valproate, lamotrigine Primary Generalized - tonic-clonic: valproate, carbamazepin, phenytoin, lamotrigine Primary Generalized - myoclonic and tonic: valproate, clonazepam Some of the patients do not get benefits from the medical treatment. The only option left for them is surgical resection of the hyperactive area in the brain. This is a very sophisticated procedure, which requires exact location of the area of brain with abnormal hyper excitability (Carpenter ch:125). Treatment of choice for status epilepticus has been diazepam even in the presence of other drugs. At the same time it has also been observed that patients to which diazepam is prescribed they need earlier endo-tracheal intubation than those who are started on phenobarbital, phenytoin, and lorazepam (Wikipedia). Origins The incidence of seizures is different in developed and developing countries. In the developed world, among the whole population 2-4 percent of the individuals experience recurrent seizures during the course of their life while in the developing countries the frequency of the disease is even higher. Overall, in the world more than 50 million individuals are affected by seizures. Among individuals, age and gender show different predilections for the disease. The extremes of age are affected more and the incidence is greater in males as compared to females. The most common type of seizures at the onset of the disease is partial focal seizures; 40 percent of children and 75 percent of the adults present with these seizures at the onset (Carpenter ch:125). Genes have also been implicated as causes of epileptic origins. But specific locations of genes in the development of epilepsy still have to be demarcated. Neuronal migration defects have been found associated with the causes of genetic and acquired epilepsy. Channel dysfunction has also been discovered as related to quite a long list of epileptic seizures (Carpenter ch:125). It is interesting to be noted that most but not all individuals with lesions in the brain develop seizures; it is still a question why some do not develop seizures Although, it becomes difficult t identify a specific lesion but some lesions have been shown to be strongly associated with epilepsy: Hippocampal sclerosis; Ganliogliomas; Glial tumors; Cavbernous malformations; Neuronal migrational defects; Hamartomas; Encephalitis; Cerebral trauma Hemorrhage. Major contributing factors for the development of seizures in children and adults remain the same but with different frequency (Carpenter ch:125). In both the children and adults, idiopathic/cryptogenic causes are the main category for developing epilepsy but it is higher in children (67.6%) as compared to the adults (55.4%). As age advances, the frequency of the factors contributing to seizures shift from the genes related causes to the environmental factors. In children, genetical factors are the second most common cause (20%) while vascular causes are second most common cause in adults (15.5%). The other causes in children and adults are: trauma (children 4.7% vs. adults 9.9%), neoplastic (children 1.5% vs. 10.5%), infections (children 4.0% vs. 2.2%) and degenerative (children 0.7% vs. adults 3.3%) (Carpenter ch: 125). In a study carried out on the patients with hippocampal sclerosis, mean age at the start of the diseases was 10.8 years, with more female patients as compared male, although there was no significant difference. On the other hand, male patients showed comparatively more association with generalized seizures, while female had more frequency of experiencing aura as compared to male patients (Janszky p.774). The medical treatment for epilepsy has got a history. But to improve the compliance and get better results research always continues. Reviews were carried out to compare the effectiveness of newer epileptic drugs with the older one in both the adults and the children. Research studies carried out on adults reflect that newer monotherapy was an important treatment choice when older drugs were found either resistant, produced side effects are where these drugs were contraindicated. But the information showing any effectiveness was different but not to a significant level (Wilby p.157). At the same time, in children, review revealed that newer drugs were not effective to a substantial level but tolerance of the children to these drugs may be better than those of older drugs. So at times these newer drugs may be prescribed by weighing the existing situation (Connock p.118). Works Cited Carpenter, Charles Robert Griggs and Joseph Loscalzo. Cecil Essentials of Medicine. India: Elsevier 2004. Connock M, Frew E, Evans BW, Bryan S, Cummins C, Fry-Smith A, Li Wan Po A, Sandercock J." The clinical effectiveness and cost-effectiveness of newer drugs for children with epilepsy. A systematic review." Health Technol Assess March 2006. ix-118 Janszky J, Schulz R, Janszky I, Ebner A. "Medial temporal lobe epilepsy: gender differences." J Neurol Neurosurg Psychiatry May 2004. 773-5 Wikipedia the free encyclopedia. 27 April 2007. Seizures. 30 April 2007. Wilby J, Kainth A, Hawkins N, Epstein D, McIntosh H, McDaid C, Mason A, Golder S, O'Meara S, Sculpher M, Drummond M, Forbes C. "Clinical effectiveness, tolerability and cost-effectiveness of newer drugs for epilepsy in adults: a systematic review and economic evaluation." Health Technol Assess April 2005. 1-157 Read More