Neuron stimulation-termination imbalance in the brain induces surges of electrical activities or seizures. They can result in loss of function in specific areas of the brain, depending on the trigger. They can reduce your cognitive abilities and manifest as behavioral abnormalities. They can hamper brain growth, affect memory recall, cause behavior changes and mood disorders.
A seizure (also called a fit, spell, or convulsion) is a sudden change of electrical activity that occurs after the disruption of the electrical communication between neurons (a type of brain cell). This can lead to abnormal electrical activity in the brain, causing noticeable symptoms such as violent shaking, uncontrollable jerking of legs and arms, and loss of control or consciousness. In some people, however, the symptoms could be very brief and undetectable.
If a person has had more than one seizure and the seizures are not provoked or caused by another treatable medical condition, the person is said to have epilepsy, a neurological condition where there is a tendency to have seizures. Seizures are not a disease in themselves. Instead, they are a symptom of many different disorders that can affect the brain.1, 2
Seizures: Types, Causes, and Symptoms
The type of seizure depends on which part and how much of the brain is affected and what happens during the seizure. The two broad categories of epileptic seizures are:
- Generalized seizures: Seizures that appear to begin everywhere in the brain at once are classified as generalized seizures.
- Partial seizures: Seizures beginning in one location of the brain are called partial seizures.
The electrical activity in the brain is caused by complex chemical changes that occur in nerve cells. In normal conditions, there is a balance of brain cells that excite the generation of chemical messages in the brain and those that can stop these messages. However, when a seizure occurs, there may be too much or too little activity, causing an imbalance between exciting and stopping activities and leading to surges of electrical activity. This condition can be traced back to various factors.
- Genetic influence, when seizures run in the family
- Brain conditions that cause damage to the brain, such as brain tumors or strokes
- A scar in the brain as a consequence of an injury
- Infectious diseases, such as meningitis, AIDS, and viral encephalitis
- Developmental disorders such as autism and neurofibromatosis3
Seizures usually last only a few seconds or minutes, but sometimes continue for 5 to 10 minutes. During a seizure, the sudden abnormal electrical disturbance in the brain results in one or more of the following symptoms.
- Stiffening, violent shaking, or strange movement of the head, body, arms, legs, or eyes
- Staring and unresponsiveness
- Lip smacking, chewing, or fumbling movements
- Strange sensations: smell, sound, feeling, taste, or visual images
- Difficulty in speaking or understanding others
- Confusion, drowsiness, disorientation
Conditions That Could Increase Risk Of Having A Seizure
- High fever
- Loss of sleep and extreme fatigue
- Drug and alcohol use
- Chemical changes in the body such as low sodium or magnesium or high calcium4
Impact Of Seizures On Your Brain
A number of experimental studies indicate that seizures can cause brain damage. Seizures are clearly capable of injuring the brain and are likely to cause negative changes in brain function. They may also result in the loss of specific brain cells. However, this may be highly dependent on the type of seizure and the specific cause of the seizure. When seizure activity is markedly prolonged, brain damage can occur quickly and be profound 5.
Studies also show that certain genes may protect the brain or make it more susceptible to injury after seizures. Scientists are conducting various animal experimentation studies to identify these important genes.6.
According to research studies, seizures can have a direct adverse effect on cognition. Cognitive decline (the gradual and chronic loss of mental abilities over time) was found to be severe and occurred across a wide range of cognitive functions. Children with recurrent seizures were found to be at significant risk for cognitive impairment and behavioral abnormalities.
In several case studies, repeated tests that create detailed images of the organs and tissues (magnetic resonance imaging) showed a progressive reduction in the hippocampal region, a major component of the human brain, following repeated seizures. This reduction was also associated with significantly poorer cognitive status.7, 8, 9
Rewiring Of Brain Circuitry
Recurrent seizures in the developing human brain is associated with adverse and widespread impairments of the growth and development of both the structure and the function of the brain. Besides killing cells, epileptic seizures adversely alter brain function in other ways as well. Memory deficits, behavioral modifications, and mood disorders can be triggered by these changes. The modifications in the brain and the birth of new cells can also cause further seizures.10, 11, 12
Substantial experimental research suggests that the brain’s susceptibility to seizure-induced injury is age-specific. While the immature brain of a child is highly prone to develop seizures, it is more resistant than the adult brain to the damage caused by seizures [Sutula T and Pitkänen A. Do seizures injure the brain. Progress in Brain Research 135. New York: Elsevier Science; 2002]. Repeated seizures of any type may pose a serious risk to the quality of life and take a long-term toll on intellectual function.
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