A generalized tonic–clonic seizure, or GTCS, previously known as a Grand mal seizure, is a type of generalized

seizure An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with los ...

that produces bilateral,

convulsive A convulsion is a medical condition where the body muscles contract and relax rapidly and repeatedly, resulting in uncontrolled shaking. Because epileptic seizures typically include convulsions, the term ''convulsion'' is sometimes used as a s ...

tonic and then clonic

muscle contractions Muscle contraction is the activation of tension-generating sites within muscle cells. In physiology, muscle contraction does not necessarily mean muscle shortening because muscle tension can be produced without changes in muscle length, such as ...

. Tonic-clonic seizures are the seizure type most commonly associated with epilepsy and seizures in general and the most common seizure associated with metabolic imbalances. It is a misconception that they are the sole type of seizure, as they are the main seizure type in approximately 10% of those with

epilepsy Epilepsy is a group of non-communicable neurological disorders characterized by recurrent epileptic seizures. Epileptic seizures can vary from brief and nearly undetectable periods to long periods of vigorous shaking due to abnormal electrical ...

. These seizures typically initiate abruptly with either a focal or generalized onset, the former being known as focal to bilateral tonic-clonic seizure. The seizure itself includes tonic (sustained) and then clonic (repetitive short) contractions. In some seizures, the tonic phase may be preceded by brief, arrhythmic muscle jerks (myoclonus), by a clonic phase or by an

absence seizure Absence seizures are one of several kinds of generalized seizures. These seizures are sometimes referred to as petit mal seizures (from the French for "little illness", a term dated in the late 18th century). Absence seizures are characterized by ...

. After the GTCS, there is an extended postictal state where the person is unresponsive and commonly sleeping with loud snoring. There is usually pronounced confusion upon awakening.

Causes

The vast majority of generalized tonic-clonic seizures have a focal origin they start as a smaller seizure that occurs solely on one side of the brain and is referred to as a focal (or partial) seizure. These unilateral seizure types (formerly known as simple partial seizure or a complex partial seizure and now referred to as focal aware seizure and focal impaired awareness seizure, respectively) can then spread to both hemispheres of the brain and cause a generalized tonic-clonic seizure. This type of seizure has a specific term called "focal to a bilateral tonic-clonic seizure. Other generalized tonic-clonic seizures are idiopathic, start in large networks involving both hemispheres, and have a presumed genetic cause. Precipitating factors include chemical and

neurotransmitter A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a synapse. The cell receiving the signal, any main body part or target cell, may be another neuron, but could also be a gland or muscle cell. Neuro ...

imbalances and a genetically or situationally determined seizure threshold, both of which have been implicated. The seizure threshold can be altered by

fatigue Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve ...

malnutrition Malnutrition occurs when an organism gets too few or too many nutrients, resulting in health problems. Specifically, it is "a deficiency, excess, or imbalance of energy, protein and other nutrients" which adversely affects the body's tissues a ...

, lack of sleep or rest,

hypertension Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. Long-term high bl ...

stress Stress may refer to: Science and medicine * Stress (biology), an organism's response to a stressor such as an environmental condition * Stress (linguistics), relative emphasis or prominence given to a syllable in a word, or to a word in a phrase ...

diabetes Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ap ...

, the presence of strobe-flashes or simple light/dark patterns, raised

estrogen Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal acti ...

levels at

ovulation Ovulation is the release of eggs from the ovaries. In women, this event occurs when the ovarian follicles rupture and release the secondary oocyte ovarian cells. After ovulation, during the luteal phase, the egg will be available to be fertilized ...

fluorescent lighting A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, which produces short-wave ultraviolet ligh ...

, rapid motion or flight,

blood sugar Glycaemia, also known as blood sugar level, blood sugar concentration, or blood glucose level is the measure of glucose concentrated in the blood of humans or other animals. Approximately 4 grams of glucose, a simple sugar, is present in the blo ...

imbalances,

anxiety Anxiety is an emotion which is characterized by an unpleasant state of inner turmoil and includes feelings of dread over anticipated events. Anxiety is different than fear in that the former is defined as the anticipation of a future threat wh ...

antihistamines Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. Typically, people take antihistamines as an inexpensive, generic (not patented) drug that can be bought without a prescription and provides re ...

and other factors. Tonic–clonic seizures can also be induced deliberately with

electroconvulsive therapy Electroconvulsive therapy (ECT) is a psychiatry, psychiatric treatment where a generalized seizure (without muscular convulsions) is electrically induced to manage refractory mental disorders.Rudorfer, MV, Henry, ME, Sackeim, HA (2003)"Electroco ...

. In the case of symptomatic focal epilepsy, the cause is often determined by

MRI Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves ...

or other

neuroimaging Neuroimaging is the use of quantitative (computational) techniques to study the structure and function of the central nervous system, developed as an objective way of scientifically studying the healthy human brain in a non-invasive manner. Incre ...

techniques showing that there is some degree of damage to a large number of

neurons A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. N ...

. The

lesions A lesion is any damage or abnormal change in the tissue of an organism, usually caused by disease or trauma. ''Lesion'' is derived from the Latin "injury". Lesions may occur in plants as well as animals. Types There is no designated classifi ...

(i.e., scar tissue) caused by the loss of these neurons can result in groups of neurons forming a seizure "focus" area with episodic abnormal firing that can cause seizures if the focus is not abolished or suppressed via

anticonvulsant Anticonvulsants (also known as antiepileptic drugs or recently as antiseizure drugs) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of b ...

drugs.

Mechanism

Prodrome

Most generalized tonic–clonic seizures begin without warning and abruptly, but some epileptic patients describe a

prodrome In medicine, a prodrome is an early sign or symptom (or set of signs and symptoms) that often indicates the onset of a disease before more diagnostically specific signs and symptoms develop. It is derived from the Greek word ''prodromos'', meaning ...

. The prodrome of a generalized tonic–clonic seizure is a sort of premonitory feeling hours before a seizure. This type of prodrome is distinct from stereotypic aura of focal seizures that become generalized seizures.

Phases

A tonic–clonic seizure comprises three phases: the '' tonic'' phase, ''

clonic Clonus is a set of involuntary and rhythmic muscular contractions and relaxations. Clonus is a sign of certain neurological conditions, particularly associated with upper motor neuron lesions involving descending motor pathways, and in many cas ...

'' phase and '' postictal'' phase. * The tonic phase is usually the first phase. Consciousness will quickly be lost and the

skeletal muscles Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscle ...

will suddenly tense, often causing the extremities to be pulled towards the body or rigidly pushed away from it, which will cause the patient to fall if standing or sitting. There may also be upward deviation of the eyes with the mouth open. The tonic phase is usually the shortest part of the seizure, normally lasting only 10–20 seconds. The patient typically expresses brief vocalizations like a loud moan upon entering the tonic stage, due to air being forcefully expelled from the lungs. This vocalization is commonly referred to as an "ictal cry". Starting in the tonic phase, there may also be bluing of the skin from respiration impairment and pooling of

saliva Saliva (commonly referred to as spit) is an extracellular fluid produced and secreted by salivary glands in the mouth. In humans, saliva is around 99% water, plus electrolytes, mucus, white blood cells, epithelial cells (from which DNA can be ...

in the back of the throat. Increased

blood pressure Blood pressure (BP) is the pressure of circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term "blood pressure" r ...

, pupillary size and

heart rate Heart rate (or pulse rate) is the frequency of the heartbeat measured by the number of contractions (beats) of the heart per minute (bpm). The heart rate can vary according to the body's physical needs, including the need to absorb oxygen and excr ...

(

sympathetic response The sympathetic nervous system (SNS) is one of the three divisions of the autonomic nervous system, the others being the parasympathetic nervous system and the enteric nervous system. The enteric nervous system is sometimes considered part of the ...

) may also be noted with clenching of the jaw possibly resulting in biting the tongue. The initial tonic phase may be preceded by repetitive rhythmic or arrhythmic jerks or by the absence seizure. * The clonic phase is an evolution of the tonic phase and is caused by muscle relaxations superimposed on the tonic phase muscle contractions. This phase is longer than the tonic phase with the total ictal period usually lasting no longer than 1 minute. Skeletal muscles will start to contract and relax rapidly, causing

convulsion A convulsion is a medical condition where the body muscles contract and relax rapidly and repeatedly, resulting in uncontrolled shaking. Because epileptic seizures typically include convulsions, the term ''convulsion'' is sometimes used as a s ...

s. These may range from exaggerated twitches of the limbs to violent shaking or vibrating of the stiffened extremities. The patient may roll and stretch as the seizure spreads. Initially, these contractions are of a high frequency and low amplitude, which will gradually progress to decreased frequency and high amplitude. An eventual decrease in contraction amplitude just before seizure cessation is also typical. * The postictal phase causes are multifactorial to include alteration of

cerebral blood flow Cerebral circulation is the movement of blood through a network of cerebral arteries and veins supplying the brain. The rate of cerebral blood flow in an adult human is typically 750 milliliters per minute, or about 15% of cardiac output. Arterie ...

and effects on multiple

s. These changes after a generalized tonic–clonic seizure cause a period of postictal sleep with stertorous breathing.

Confusion In medicine, confusion is the quality or state of being bewildered or unclear. The term "acute mental confusion"

and total

amnesia Amnesia is a deficit in memory caused by brain damage or disease,Gazzaniga, M., Ivry, R., & Mangun, G. (2009) Cognitive Neuroscience: The biology of the mind. New York: W.W. Norton & Company. but it can also be caused temporarily by the use ...

upon regaining consciousness are also usually experienced and slowly wear off as the patient becomes gradually aware that a seizure occurred and remembers their identity and location. Most often, patients regain consciousness within 30 minutes. Rarely, impaired consciousness duration can last several hours after a seizure, especially with a compounding central nervous system condition or a prolonged seizure. Occasionally the patient may vomit or burst into tears from the experienced mental trauma. An additional smaller seizure can also occur several minutes after the main seizure, particularly if the patient's

seizure threshold The term seizure threshold is used to describe the balance between excitatory (glutaminergic) and inhibitory ( GABA-ergic) forces in the brain which affect how susceptible a person is to seizures. Those diagnosed with epilepsy or certain other neur ...

has been brought unusually low by known factors or combinations of such. Examples include: severe

hangover A hangover is the experience of various unpleasant physiological and psychological effects usually following the consumption of alcohol, such as wine, beer, and liquor. Hangovers can last for several hours or for more than 24 hours. Typical sympto ...

sleep deprivation Sleep deprivation, also known as sleep insufficiency or sleeplessness, is the condition of not having adequate duration and/or quality of sleep to support decent alertness, performance, and health. It can be either chronic or acute and may vary ...

, elevated

at ovulation, prolonged physical tiredness, and drug use or abuse (including, but not limited to,

stimulant Stimulants (also often referred to as psychostimulants or colloquially as uppers) is an overarching term that covers many drugs including those that increase activity of the central nervous system and the body, drugs that are pleasurable and inv ...

alcohol Alcohol most commonly refers to: * Alcohol (chemistry), an organic compound in which a hydroxyl group is bound to a carbon atom * Alcohol (drug), an intoxicant found in alcoholic drinks Alcohol may also refer to: Chemicals * Ethanol, one of sev ...

and

caffeine Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class. It is mainly used recreationally as a cognitive enhancer, increasing alertness and attentional performance. Caffeine acts by blocking binding of adenosine t ...

). Rarely, the respiration is inhibited during the postictal phase, leading to

sudden unexpected death in epilepsy Sudden unexpected death in epilepsy (SUDEP) is a fatal complication of epilepsy. It is defined as the sudden and unexpected, non-traumatic and non-drowning death of a person with epilepsy, without a toxicological or anatomical cause of death det ...

(SUDEP). Generalized tonic–clonic seizures represent the most important risk factor for SUDEP, especially in patients with nocturnal seizures, who are living alone or do not share a bedroom.

Diagnosis

Diagnosis can be made definitively by video recordings of the seizures and

electroencephalography Electroencephalography (EEG) is a method to record an electrogram of the spontaneous electrical activity of the brain. The biosignals detected by EEG have been shown to represent the postsynaptic potentials of pyramidal neurons in the neocortex ...

(EEG), which records the electrical activity of the brain. This is typically done after a seizure episode in a clinical setting with an attempt to "capture" a seizure while it happens. According to the "Harrison's Manual of Medicine," the EEG during the tonic phase will show a "progressive increase in low-voltage fast wave activity, followed by generalized high-amplitude, poly spike discharges." The clonic phase EEG will show "high amplitude activity that is typically interrupted by slow waves to create a spike-and-slow-wave pattern." Additionally, the postictal phase will show suppression of all brain activity, then slowing that gradually recovers as the patient awakens.

Management

For a person experiencing a tonic–clonic seizure,

first-aid First aid is the first and immediate assistance given to any person with either a minor or serious illness or injury, with care provided to preserve life, prevent the condition from worsening, or to promote recovery. It includes initial int ...

treatment includes rolling the person over into the

recovery position In first aid, the recovery position (also called semi-prone) is one of a series of variations on a lateral recumbent or three-quarters prone position of the body, often used for unconscious but breathing casualties. An unconscious person, a perso ...

, which can prevent

asphyxiation Asphyxia or asphyxiation is a condition of deficient supply of oxygen to the body which arises from abnormal breathing. Asphyxia causes generalized hypoxia, which affects primarily the tissues and organs. There are many circumstances that can i ...

by preventing fluid from entering the lungs. Other general actions to take as recommended by the

Epilepsy Foundation The Epilepsy Foundation, also Epilepsy Foundation of America (EFA), is a non-profit national foundation, headquartered in Bowie, Maryland, dedicated to the welfare of people with epilepsy and seizure disorders. The foundation was established in 196 ...

include staying with a person until a seizure is over, paying attention to length of seizure as a possible indication for

status epilepticus Status epilepticus (SE), or status seizure, is a single seizure lasting more than 5 minutes or 2 or more seizures within a 5-minute period without the person returning to normal between them. Previous definitions used a 30-minute time limit. The s ...

and/or indication to give rescue medication and call for emergency help, moving close objects out of the way to prevent injury. It is also not recommended to hold a person down that is having a seizure, as that can lead to injury. Nor should anything be put in a person's mouth, as these items can become choking hazards and, depending on what is put in, can potentially break the person's teeth. Long-term therapy may include the use of

antiepileptic drugs Anticonvulsants (also known as antiepileptic drugs or recently as antiseizure drugs) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of b ...

, surgical therapy, diet therapy (

ketogenic diet The ketogenic diet is a high- fat, adequate-protein, low-carbohydrate dietary therapy that in conventional medicine is used mainly to treat hard-to-control (refractory) epilepsy in children. The diet forces the body to burn fats rather than ca ...

vagus nerve stimulation Vagus nerve stimulation (VNS) is a medical treatment that involves delivering electrical impulses to the vagus nerve. It is used as an add-on treatment for certain types of intractable epilepsy and treatment-resistant depression. Medical use VN ...

, or

deep brain stimulation Deep brain stimulation (DBS) is a neurosurgical procedure involving the placement of a medical device called a neurostimulator, which sends electrical impulses, through implanted electrodes, to specific targets in the brain (the brain nucleu ...

Terminology

Generalized tonic–clonic seizures can have a focal onset (described above) that progresses into a generalized seizure or be a generalized seizure at the onset. The term "Grand Mal" is outdated and nonspecific, referring to generalized tonic-clonic seizures with either a focal or generalized onset.

References

External links

* {{DEFAULTSORT:Tonic-clonic seizure Seizure types de:Konvulsion