Unraveling the Mystery of Epilepsy: Understanding Seizures, Causes, and Neurological Impacts

Introduction

Epilepsy refers to a disabling neurologic condition which is one of the most common conditions in the modern world. In order to understand this condition, one must first understand what a seizure is. A seizure can be defined as the resultant paroxysmal alteration effected by hypersynchronous and excessive discharge of neurons in certain parts of the brain. This alteration is usually an alteration of the neurologic function (Stafstrom & Carmant, 2015). This usually happens in two distinct ways: The first refers to the alteration from abnormal firing of the neurons; the second refers to that which is caused by a non-epileptic event. This is what distinguishes epileptic seizures. Epilepsy, thereof, is the condition that refers to unprovoked and recurrent seizures. Notably, not all persons who suffer from a seizure have epilepsy.

The brain is made up of billions of nerve cells, also referred to as neurons. These nerve cells produce and receive electric impulses from various other parts of the nervous system. Communication from one neuron to the other usually occurs through these electric impulses. The excessive or abnormal activity caused by a seizure disrupts these communications.

In many occasions, the causes of seizures are unknown. However, seizures may happen after strokes, closed injuries to the head, certain infections, for instance meningitis or some other illnesses (Schachter, 2019). Non- epileptic seizures can also be caused by other factors such as low levels of sugar in the blood, fainting spells and even anxiety attacks. In some cases, seizures are also referred to as convulsions. This is because when seizures occur, the person uncontrollable shakes in rapid and rhythmic convulsions of the muscles: the muscles contract and relax repeatedly.

Historically, epilepsy was thought to originate from demons, divine circumstances or spirits. This has been the belief in many cultures. It is only until the 400 BC that the Greek physician Hippocrates considered an occurrence of epilepsy as a medical issue. However, Hippocrates still believed that this medical condition was effected by humour imbalance; four, to be more precise. These humours comprised of the blood, the yellow bile, the black bile and the phlegm. John Hughlings, an English doctor, was the next person to believe that epilepsy is a medical condition. This happened in the late 19th century. Eventually, the modern definition of epilepsy was adopted from Jackson, who defined the condition as a disorderly, excessive and occasional discharge of the nerve tissue. Over the years, the development of technology has enabled the world to learn even more about seizures and epilepsy; important factors such as how and why they occur in certain cases.

Epilepsy does affect all groups of persons, from children to the elderly. More than 2.5 million people in the world suffer from epilepsy. Children from birth to the age of nine largely contribute to this number (47%). The 10-19 year olds contribute to over 30% of these suffering.

Body

Seizures can be divided into various categories which range in both severity and length. This division is usually dependent on the part of the brain they affect. Ideally, seizures differ depending on which part of the brain the abnormal discharge occurs, the number of neurons involved and the period of time the discharge lasts. Some seizures may be harmless or subtle while others may be life threatening. Epilepsy, being a condition that disrupts the activities of the brain, can affect most, if not all parts of the body (Watson, 2017). A tonic- clonic seizure may take about 7 minutes whereas absence seizures may last for a few seconds.

These different types have different symptoms. Symptoms would depend on which part of the brain is involved and they may include brief blackouts after the experience, changes in behavior, frothing or drooling, movements of the eyes, snorting or grunting, uncontrollable bowels or bladder, changes in moods among others. Seizures can be divided into three main categories: focal, epileptic and generalized (Berg et al, 2010). Neuronal networks limited to one part of the cerebral hemisphere cause focal seizures. Seizures that begin from neuronal networks bilaterally distributed are generalized seizures. The point of origin of these seizures may either be the cortex or the subcortical structures. A seizure may start as a focal seizure and still end up being a generalized seizure (Stafstrom & Carmant, 2015)

There are also other subtypes of seizures under these main ones. For instance, generalized seizures include absence, myoclonic, and atonic and generalized tonic- clonic. Through the various types of seizures, respective epilepsies can be classified: The temporal lobe epilepsy is the most common type of epilepsy whereas the frontal lobe epilepsy is the second most common type (Panayiotopoulos, 2005). Both of these types are characterized by the occurrence of partial seizures. Partial seizures can occur in two different ways: either as simple seizures or complex seizures. The occurrence of simple partial seizures does not really affect the memory or mental awareness. Complex partial seizures, on the other hand, manifest in the neurons leading to memory disturbance.

In cases of partial seizures, the patient is usually mentally aware of what is happening. Throughout the seizure, the patient may be aware of his/her surroundings even though he/she may not be able to communicate with any other person. Partial seizures occur due to the limitation in areas of the brain of the neurons which cause movement, emotion and sensation. Some of the symptoms in this case would include tingles in the hand or face, hallucinations or visual distortions. First aid that may be helpful to patients with partial seizures may be to sit the person down in a safe place and in the process move away any dangerous items around them. During the seizure, it is not advisable to hold the person down; instead, it is acceptable to stay with the patient until when alertness kicks in. In cases of generalized seizures, the patient may experience loss of consciousness for a while.

Through the use of an EEG machine, clinical practitioners are able to record the electronic impulses sent and received by neurons in the brain (Poh et al, 2012). The spike and slow wave discharge is the pattern that would normally be depicted; this signifies no abnormal occurrences. The function of the spike phase is to depict an abnormal electrical output in single brain cells and the slow wave phase shows an electrical input in these single cells. As a result of a seizure, only the spike phase can be seen. The results basically mean that there is an excessive spread of discharges through the neuronal network.

The frontal lobe epilepsy can be characterized by recurring and brief seizures that take place within the frontal lobes of the brain. They occur mostly when the patient is asleep. The frontal lobes of the brain are in charge of many unknown duties and functions. This provides its uniqueness, the lack of sufficient knowledge surrounding the frontal lobe functions may lead to misdiagnoses. The frontal lobe roles include executive processes, expression of emotions, language coordination and movement (Bernhardt et al, 2013).

The frontal lobes are the largest part of the brain, volumetrically. Despite their size, their functions are somewhat elusive to many neuropsychologists. It can be known, however, that they perform functions such as storage of memories, thoughts in abstract, self-control, judgment and concentration. The lobe is situated directly behind the forehead. It contains the prefrontal cortex and the primary motor cortex. The neurons in the prefrontal cortex are 16 times as many compared to the primary visual cortex. The prefrontal cortex is therefore capable of transmitting a greater deal of information (Fisher, 2014). Seizures that occur from these areas of the brain may, in that regard, tend to show unusual symptoms. These symptoms may be misdiagnosed as non-epileptic seizures, sleep disorders or psychiatric disorders.

There are several steps involved in the diagnosis of Epilepsy. The parents’ history has to be first confirmed. After confirmation, a full neurological exam would be conducted. After the examination, blood and clinical tests would be taken just to affirm that other conditions are not in play. The best tool for the performance of this diagnosis is the EEG. This machine would help in the identification of the type of seizure and also the determination of the cause of the epilepsy. The accuracy of the results would be important as they would help determine the best method of treatment.

The frontal lobe syndrome refers to a range of behaviors that result from damage caused to the frontal lobe. The frontal lobe can be damaged by various factors. These factors include tumors, lesions and strokes (Mansouri et al, 2019). Tumors may damage the frontal lobe through the causation of pressure onto the lobe, such as can be seen in cases of subdural hematoma, meningioma and meningitis. Strokes, on the other hand, may cause damage by corrupting the ventral and medical frontal lobe. A head blow or sudden change of motion may cause the bone structures just below the frontal lobes to tear the axons, leading to damage by lesions.

Conclusion

A number of people suffering from refractory focal epilepsy seem to have the frontal lobe epilepsy. Unilateral clonic, tonic asymmetry and hypermotor seizures are examples of typical semiology for the frontal lobe epilepsy. Through the EEG, a rhythmical midline theta of localizing value usually reveals an interictal epileptiform. A large volume of the frontal lobe cortex is usually unseen to electrodes. This fact, together with frequent muscle artifacts in motor seizures, limits the usefulness of ictal EEG recordings. In about a third of patients with epilepsy, Frontal lobe epilepsy is localized through ictal single photon emissions CT and positron emission tomographies (Mansouri et al, 2019).

Frontal lobe epilepsy may be treated in a number of ways. The most common of these treatments involves the use of anticonvulsant medications. These medications help in the prevention of future seizures. In some cases, professionals may choose to operate on the patient. This is conducted so that the focal area of the brain can be removed. The goal of medication is usually to try and reduce the chances of repetition of seizures by limiting the amount of extensive or rapid discharging of neurons, therefrom the focal region cannot be over- activated. Understanding molecular and cellular events has been possible because of the deciphering of the pathophysiology of epilepsy. More than 500 genes have been discovered to be associated with epilepsy (Devinsky et al, 2018). From this discovery, new animal models, more targeted therapies and more precise therapies.

References

Devinsky, O., Vezzani, A., Trrence, J., Jette., Sheffer, I., Perucca P 2018, Epilepsy. Nature Reviews Disease Primers

Berg, A., Berkovic, S., Brodie, M., Buchhalter, J., Cross, J., Boas, W., Engel, J., Glauser, T., Mathern, G., Moshe, S 2010, Revised terminology and concepts for organization of seizures and epilepsy: Report of the ILAE Commision on Classification and Terminology, 2005-2009. Epilepsia, 51.

Bernhardt, B., Hong, S., Bernasconi, A., Bernasconi, N 2013, Imaging structural and functional brain networks in temporal lobe epilepsy, Front Hum Neurosci 7

Fisher, R 2014, ILAE Official Report: A practical clinical definition of epilepsy, Epilepsia 55

Mansouri, A., Singh, S., Sayood, K 2019, Online EEG Seizure detection and Localization, University of Nebraska, Lincoln.

Panayiotopoulos, C 2005, Symptomatic and Probably Symptomatic Focal Epilepsies: Topographical Symptomatology and Classification, Blandon Medical Publishing.

Poh, M., Loddenkemper, T., Reinsberger, C., Swenson, N., Goyal, S., Madsen, M., Picard R 2012, Autonomic changes with seizures correlate with postictal EEG suppression, Cambridge, USA.

Schachter, S 2019, Patient education: Seizure in adults (Beyond the Basics)(Accessed on 11th December, 2019)

Stafstrom, C 2015, Seizures and Epilepsy: An overview for Neuroscientists, Cold Spring Harbor Perspectives in Medicine, DOI.

Watson, S 2017, The Effects of Epilepsy on the Body (Accessed on 11th December, 2019)

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