What is a seizure?

The brain is a highly complex and sensitive organ. It controls and regulates all our actions. It controls motor movements, sensations, thoughts, and emotions. It is the seat of memory, and it regulates the involuntary inner workings of the body such as the function of the heart and the lungs.

The brain cells work together, communicating by means of electric signals. Occasionally there is an abnormal electrical discharge from a group of cells, and the result is a seizure. The type of seizure will depend upon the part of the brain where the abnormal electrical discharge arises.

What is an aura?

Before the onset of a seizure some people experience a sensation or warning called an “aura”. The aura may occur far enough in advance to give the person time to avoid possible injury. The type of aura experienced varies from person to person. Some people feel a change in body temperature; others experience a feeling of tension or anxiety. In some cases, the aura will be apparent to the person as a musical sound, a strange taste, or even a particular curious odour. If the person is able to give the physician a good description of this aura, it may provide a clue to the part of the brain where the initial discharges originate. An aura could occur without being followed by a seizure and in some cases can by itself be called a type of focal seizure.

Types of seizures

Epilepsy encompases a wide variety of different seizures. Frequency and form of attacks vary greatly from person to person. With modern methods of treatment, however, many cases can be controlled. Because there are so many nuances in Epilepsy and so many different kinds of seizures, a specific classification system is being promoted by the International League Against Epilepsy. The International Classification of Epilepsy Seizures has been adopted by the medical community and is gradually replacing outdated seizure terminology including “grand mal” and “petit mal”.

The new classification scheme describes two major types of seizures: “focal” and “generalized”. It also divides each of these categories into subcategories including focal dyscognitive seizures, absence seizures, tonic-clonic seizures, and other types.

Focal seizures

Focal seizures with elementary symptomology were formely known as partial seizures. During this type of seizure the patient can experience a range of strange or unusual sensations including sudden, jerky movements of one body part, distortions in hearing or seeing, stomach discomfort, or a sudden sense of fear. Consciousness is not impaired. If another seizure type follows, these sensations may be referred to as an “aura”.

Focal dyscognitive seizures

Focal dyscognitive seizures (formerly complex-partial seizures) are characterized by a complicated motor act involving impaired consciousness. During the seizure the patient appears dazed and confused. Purposeless behaviours such as random walking, mumbling, head turning, or pulling at clothing may be observed. Usually, these so-called “automatisms” cannot be recalled by the patient. In children this seizure may consist of staring or lip-smacking, and therefore may be confused with the absence seizure described below.

Absence (petit mal) seizures

Generalized absence seizures (formerly petit mal) are characterized by 5 to 15 second lapses in consciousness. During this time the patient appears to be staring into space and the eyes may roll upwards.

Absences are not preceded by an aura and activity can be resumed immediately afterwards. Typically, they occur in children and disappear by adolescence. They may, however, evolve into other seizure types, such as focal dyscogntive (complex-partial) or tonic-clonic. The occurrence of absence seizures in adulthood is rare.

Tonic-clonic (grand mal) seizures

The tonic-clonic (formerly grand mal) seizure is a generalized convulsion involving two phases. In the tonic phase, the individual loses consciousness and falls, and the body becomes rigid. In the clonic period the body extremities jerk and twitch. After the seizure, consciousness is regained slowly. If the tonic-clonic seizure begins locally (with a focal seizure) it may be preceded by an “aura”.

Other types of seizures

Dravet Syndrome is a genetic disorder of Chromosome 2 usually affecting a gene called SCN1A, causing epilepsy and other neurological and developmental problems. Dravet Syndrome accounts for 1% of the epilepsy population.

Tuberous Sclerosis Complex (TSC) is a genetic disorder that causes non-malignant tumors to form in many different organs, primary in the brain, eyes, heart, kidney, skin and lungs.

Malignant migrating partial seizures of infancy (MMPSI) is a severe form of Epilepsy that begins very early in life. Recurrent seizures begin before the age of 6 months but commonly start within a few weeks of birth. The seizures do not respond well to treatment. Although affected individuals may develop normally at first, progression stalls and skills decline when seizures begin; as a result, affected individuals have profound developmental delay.

Benign Rolandic Epilepsy is an epileptic syndrome occurring in young children that is age limited (you stop having seizures in the teen years). Salivation and twitching of the mouth or upper extremity on one side are typical manifestations. Seizures occur almost exclusively nocturnally.

Juvenile Myoclonic Epilepsy is characterized by onset in childhood or adolescence and is associated with extremity jerking or generalized tonic clonic seizures (‘grand mal’) within an hour or two of wakening from sleep. Seizures which may be due to sleep deprivation, alcohol intake or coffee tend to occur in the morning.

Please contact your physician or Epilepsy Durham Region at clientservices@epilepsydurham.com for additional information. Other seizure terms include: Atonic (Drop Attacks), Myclonic, Infantile Spasms, Nocturnal, Photosensitive, Visual, Musicogenic, Jacksonian, Sensory, Bilateral Myclonus, Atkinetic, Autonomic, Prolonged seizures, and Ictal State.

What are “status” seizures?

Status Epilepticus is the term used to describe recurrent seizures without recovery of consciousness between attacks. This is a medical emergency and can be life threatening, or cause brain damage. Immediate action to get the necessary medical care should be taken.

What are pseudo-seizures?

Pseudo-seizures (or psychogenic seizures) are quite common and can occur in people who have, or do not have, Epilepsy. The attacks are triggered by a conscious or unconscious desire for more care and attention. The seizures start with rapid breathing, triggered by mental stress, anxiety, or pain. As the person breaths rapidly, they build up carbon dioxide in their body and change their chemistry. This can cause symptoms very much like a seizure: prickling in the face, hands, and feet, stiffening, trembling, etc. The appropriate treatment for pseudo-seizures is to calm the person and start them breathing at a normal rate. Treatment should also involve investigating the mental and emotional factors that led to the pseudo-seizure.

How do you distinguish epileptic seizures from pseudo-seizures?

Epileptic seizures and pseudo-seizures are distinguishable both by their nature and symptoms, but the diagnosis can be difficult. Epileptic seizures are caused by a change in how the brain cells send electrical signals to each other, while pseudo-seizures are triggered by a conscious or unconscious desire for more care and attention. Thus, measuring brain activity with an EEG and video telemetry is important for distinguishing epileptic and pseudo-seizures. Also, pseudo-seizures often lack the exhaustion, confusion, and nausea that is associated with epileptic seizures. Psychogenic seizures can occur in people who also experience epileptic seizures.

Can seizures occur if a person does not have Epilepsy?

Epilepsy is a chronic condition of recurrent unprovoked seizures. Isolated seizures and provoked seizures (e.g., drug or alcohol induced) are not Epilepsy even though the events are real seizures. There are many types of non-epileptic seizures. Non-epileptic seizures differ from epileptic seizures in that there is usually no evidence of abnormal electrical activity in the brain after the seizure, and they do not occur repeatedly. Some of the more common causes of non-epileptic seizures are: low blood sugar, fainting, heart disease, stroke, migraine headaches, kinked blood vessels, narcolepsy, withdrawal, and extreme stress or anxiety.

How long do the seizures last?

Depending on the type of seizure, they can last anywhere from a few seconds to several minutes. In rare cases, seizures can last many hours. For example, a tonic-clonic seizure typically lasts 1-3 minutes; if the seizure lasts longer than 5 minutes, it is considered to be a medical emergency and 911 must be called. Absence seizures may only last a few seconds, while focal dyscognitive seizures range from 30 seconds to 2-3 minutes. “Status Epilepticus” refers to prolonged seizures that can last for many hours, and this can be a serious medical condition. In most cases, however, seizures are fairly short and little first aid is required.

Disclaimer:

The information referring to epilepsy is for educational and informational purposes only.

It is not intended to provide medical care or other professional advice, nor is it intended to be used to diagnose or assess health conditions or to be substituted for professional guidance in treatment.

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