Seizures are caused due to abnormal electrical activity in the brain, which may result in convulsions, in which a person's body shakes continuously and uncontrollably. These convulsions may develop due to a number of factors, such as fever, brain tumor, injury, electrolyte imbalance, high or low blood sugar, drug withdrawal, gastrointestinal disease, medicine, and even brain injury. Older patients with a history of neurodegenerative disorders like Alzheimer's disease, are more prone to this condition. Muscle spasms, frothing at the mouth, loss of bladder or bowel control, temporary halt in breathing, and uncontrollable shaking are some of the other symptoms of this condition.
Types of Seizures
Seizures are often confused with epilepsy, because the symptoms look the same. However, there are two disorders, namely epileptic seizures and non-epileptic seizures.This article focuses on the second category. When a person has multiple and repeated seizures with no apparent cause, it is known as epilepsy. The non-epileptic ones are usually triggered by some physical or psychological factors. Certain mental disorders may also cause this condition.
Symptoms vary in their severity, and may last from 30 seconds to 2 minutes. However, if it lasts for more than 5 minutes or if a person has them successively in breaks, or becomes unconscious during an occurrence, it is a medical emergency. In 1981, the International League Against Epilepsy (ILAE) differentiated between the types, for the purposes of prognosis and treatment. According to ILAE, seizures are mainly classified into two categories or types, namely focal and primary generalized.
These are also called partial seizures, as they occur in just one part of the brain. Most patients experiencing it, stay alert and have a good memory of their actions. This form is further categorized into 3 types depending on the type of symptoms the person exhibits.
Simple Partial Seizures: These affect only one part of the brain and its symptoms may vary based on which part of the brain is involved. Following are its different types:
- Motor Seizures: In this condition, the person exhibits abnormal body movements, such as automatic hand movements and jerking or stiffening of different body parts. These movements may spread from one side to the other side of the body. In some cases, even speech has been known to be affected.
- Sensory Seizures: This affects the senses of a person. His ability to hear, taste, smell, and see are greatly affected. Some patients may experience visual hallucinations and illusions.
- Autonomic Seizures: In this type, changes occur in the nervous system, which may affect body movements, cause changes in the heart rate, and result in disturbed breathing, sweating or unpleasant sensations in the head, chest, or stomach.
- Psychic Seizures: It causes changes in the affective domain, like the way the people feel, think, and experience things. The patient will have trouble expressing himself/herself through, both spoken or written words. They may feel sudden spurts of happiness, fear, or depression, for no apparent reason. Some people have also been known to feel a sense of déja vu.
Complex Partial Seizures: When a simple partial seizure affects the temporal or frontal lobe and spreads to a larger area of the brain, it is known as complex partial seizure.
- Temporal Lobe: It starts in the temporal lobe and spreads, affecting the awareness and alertness of the person. The symptoms may feel like those of daydreaming, and most patients don't recall that they have had a seizure.
- Frontal Lobe: The duration of the seizure tends to be shorter than the one started in the temporal lobe, and results in pelvic thrusting and bicycling-like movements of the legs.
Secondarily Generalized Seizures: Some complex partial seizures turn into secondarily generalized seizures, and occur after a partial one has begun. This occurs when the sudden electrical activity spreads from a limited area to the entire brain. Some patients do not have any recollection of the first part of the attack.
Primary Generalized Seizures
This type occurs when both sides of the brain are affected by the widespread electrical activity. Heredity plays an important role in their occurrence. Seizures that fall under this category are as follows:
- Myoclonic: This occurs for a moment, during which the patient experiences jerks or twitches of a muscle or a group of muscles very rapidly. This happens mostly on one side of the body.
- Absence: These start and end abruptly and usually last for 20 seconds. The ability to respond and general awareness is impaired temporally and most patients don't even realize its occurrence. During the seizure, the person may blink repetitively, roll up the eyes, or just stare.
- Atypical Absence: Here the patient just stares, but is still responsive, though the responses are very slow. The seizures begin and end gradually, occurring for a duration of around 30 seconds, and are accompanied by slight jerking lip movements and eye blinking.
- Atonic: Also known by the name 'akinetic', which means without movement, it is characterized by loss of muscle strength. However, there is no loss of consciousness. As a result, the person's eyelids may droop and he may fall down or drop things.
- Tonic: These occur mostly during sleep and result in sudden stiffening of the body, arms, or legs. They usually last for 20 seconds, and affects most parts of the brain.
- Clonic: The word clonic is taken from 'clonus', which means rapid alternating contraction and relaxation of a muscle. This occurs rarely and the repeated jerking movements can't be restrained or repositioned.
- Tonic-Clonic: As the name implies, it has the characteristics of both tonic and clonic types. The tonic phase precedes the clonic phase; first the body stiffens and the person may fall and in the process, may bite his own tongue or lips causing bleeding from the mouth, along with froth. After this the clonic phase brings with it rapid and constant jerky body movements. This is the type that most people relate to, when the word seizure is used.
A person may be affected by more than one kind of seizures, and one that lasts for 30 seconds or more, or occurs repetitively, requires medical attention. Awareness and readily available medical help can go a long way in helping people cope with this disorder.