An absence seizure typically consists of brief lapses of awareness, i.e. the patient will suddenly interrupt his or her doings, stare blankly into space and will not react to their surroundings. Sometimes rapid blinking of the eyelids or uncontrolled movement and jerking of an arm or a leg may be observed, too [12].

These lapses of awareness generally last a few seconds. They are associated with amnesia, as the patient does not remember what happened during the seizure. Frequently, the patient just continues doing what he or she has been doing before the seizure. Since absence seizures generally do not imply physical harm nor confusion, they are not followed by a recovery period.

Particularly in case of pyknoleptic CAE, the high frequency of absence seizures may hinder the child in his or her day-to-day activities, in paying attention to class, to sports, to games. Conversations with the child may frequently be interrupted by the child's attention "wandering". It is not uncommon that the child's teacher is the first person to notice something wrong. Either parents or teacher may complain about the child's lack of attention or about the child daydreaming because they are usually not familiar with absence seizures.

• Epilepsy

  Petit Mal, Petit Mal Convulsion, Epilepsy, Minor, Minor Epilepsies, Minor Epilepsy, Pykno Epilepsy, Pykno-Epilepsies, Pykno-Epilepsy, Epilepsy, Absence [Disease/Finding], absence epilepsy, epilepsy absence, mal petit seizure, mal petit seizures, Seizure [fpnotebook.com]

  Childhood absence epilepsy (CAE), juvenile absence epilepsy (JAE) and juvenile myoclonic epilepsy (JME) are idiopathic generalized epilepsies that may involve typical absence seizures. [symptoma.com]

  [4] Among the idiopathic generalized epilepsies, absence seizures are seen in childhood absence epilepsy (pyknolepsy), juvenile absence epilepsy, and juvenile myoclonic epilepsy (impulsive petit mal). [5] The seizures in these conditions are called [emedicine.medscape.com]

• Falling

  Signs of an absence seizure “When people think of seizures, they generally think of what used to be called ‘grand mal’ seizures—where people fall to the ground and shake,” said Dr. Gotoff. [geisinger.org]

  Absence seizures fall into two categories: typical and atypical. Typical absence seizures begin abruptly, last 10 to 30 seconds, and resolve themselves without complication. [webmd.com]

  A person may make jerking movements, fall to the ground suddenly, or have stiffness in the arms and legs. But many consist of a staring spell that lasts anywhere from a few seconds to a minute. [brainfacts.org]

  They do not fall but may pause in what they are doing. Their face often looks pale with a blank expression. They may look dazed, the eyes stare and the eyelids may flutter a little. [patient.info]

• Pain

  Comfort Cool Tennis Elbow Braces - Elbow Wraps, Sleeves & Bands Finger - Thumb Supports Foot and Ankle Braces - Supports Foot Pain & Injury Hernia Aids and Support Hip Surgery and Injury Knee Braces & Support Orthopedic Back Cushions Orthopedic Pillows [activeforever.com]

  The script has a painful, personal honesty in the scenes in which Barnes and his wife try to cope with the pain of losing their only child, and what it has done to them as a couple. [amazon.com]

  Gribkoff, The role of voltage-gated calcium channels in pain and nociception, Seminars in Cell & Developmental Biology, 17, 5, (555), (2006). [doi.org]

  The patient denied fever, chills, or nausea, as well as hearing loss, ear pain, or tinnitus. She was otherwise healthy, with no history of surgery, trauma, or allergies. [medscape.com]

• Shivering

  In absence attacks there might be a brief flutter of the eyelids or a minimal shiver, and that's all. In fact, absence seizures are more notable for inactivity than for extra movements. [cordingleyneurology.com]

  Autonomic: Auras involving cold shivers and goosebumps, for example, may occur. [verywellhealth.com]

• Problems at School

  Atypical absence seizures most often affect school age children. A teacher may want to talk to the parent, because the child is having problems at school. Atypical absence seizures usually continue into adulthood. [epilepsy.com]

  Peer Relationships, Teasing, and Social Isolation Social isolation and poor peer relationships are a particular problem in school-aged and adolescent children with epilepsy. [childneurologyfoundation.org]

• Cyanosis

  Breathing may decrease or cease altogether, producing cyanosis (turning blue) of the lips, nail beds, and face. Because air is being forced past the vocal chords you may hear a cry or groan. [efepa.org]

  This usually occurs with the rapid rise of the fever and consists of a rhythmic jerking of the extremities, eye rolling, unresponsiveness, sometimes cyanosis (bluish discoloration around the mouth and the tips of the extremities), followed by 30 minutes [childbrain.com]

• Auditory Hallucination

  […] of smell or taste and a dreamlike state (uncal involvement) -complex auditory hallucinations (auditory cortex) -delusional behaviour Frontal: -motor features- posturing, versive (forced, involuntary) movements of head and eyes, peddling movements of [clumsylostmedicalstudent.wordpress.com]

  Common symptoms include auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social or occupational dysfunction. [childneurologyfoundation.org]

• Aggressive Behavior

  However, gabapentin occasionally has been reported to cause aggressive or agitated behavior. Children in whom significant adverse behavioral changes occur with use of gabapentin tend to have some degree of documentedintellectual disability. [childneurologyfoundation.org]

• Absent Minded

  See Also: abscisic acid abscissa abscission abscission layer abscission zone abscond abscondee abscondence abseil absence absence seizure absent absent without leave absent-minded absente reo absentee absentee ballot absentee landlord absentee vote absenteeism [wordreference.com]

• Uremia

  Emotional excess (e.g., fright or anger), fever, or other hypermetabolic states, hypoglycemia, hypocalcemia, hypomagnesemia, hypoxemia, and toxic states (e.g., tetanus, uremia, exogenous, excitatory agents such as amphetamine, aminophyline, lidocaine, [dartmouth.edu]

• Staring Spells

  Therefore, most staring spells are non-epileptic in nature. [ncbi.nlm.nih.gov]

  Absence seizures look like staring spells. They can happen up to 100 times a day. Because the seizures can look like daydreaming, they often go unnoticed. Sometimes, they're misdiagnosed as ADHD. [kidshealth.org]

  Steve: But the most important part on the EEG is if you don't capture the episode of the staring spells, then you haven't made the diagnosis. [howcast.com]

  However, using current terminology, there are two main kinds of staring-spell attacks--absence seizures and partial-complex seizures. [cordingleyneurology.com]

• Myoclonus

  Myoclonus of limbs can rarely occur. Oral and manual automatisms are common and there may be perseveration of behaviors occurring prior to seizure onset. Absence seizures were previously known as 'petit mal' seizures. [epilepsydiagnosis.org]

  They may occur with other types of seizures, such as generalized tonic-clonic seizures (grand mal seizures), twitches or jerks (myoclonus), or sudden loss of muscle strength (atonic seizures). Symptoms Most absence seizures last only a few seconds. [baptistjax.com]

  In terms of seizure type, the most common was generalized tonic clonic seizure (GTCS), with myoclonus, absence and other seizure types observed. There was family history present in 17 patients and valproic acid was most commonly used for treatment. [ncbi.nlm.nih.gov]

  They may occur with other types of seizures, such as generalized tonic-clonic seizures (grand mal seizures), twitches or jerks ( myoclonus ), or sudden loss of muscle strength (atonic seizures). Most absence seizures last only a few seconds. [nlm.nih.gov]

• Dizziness

  Knowing what kind of dizziness you're experiencing is useful when you're trying to explain your symptoms to a health care provider. What do I do if I feel dizzy? Dizziness is a symptom of many different conditions. [healthyhearing.com]

  First Case: Waking Up With Dizziness A 28-year-old communications director presented to her family physician with a 2-month history of dizziness, nearly always upon awakening from bed. [medscape.com]

  If you feel dizzy, the right side is affected. If you don’t feel dizzy, sit up, wait a little bit and repeat the test with your left side. If you feel dizzy when you repeat the test, your left side is affected. [webmd.com]

  The dizziness of BPPV can make you unsteady, which may put you at greater risk of falling. [mayoclinic.org]

• Vertigo

  Topic Overview What is benign paroxysmal positional vertigo (BPPV)? Vertigo is the feeling that you are spinning or the world is spinning around you. Benign paroxysmal positional vertigo is caused by a problem in the inner ear. [uofmhealth.org]

  If vertigo occurs during any of the positions, that position is held until the vertigo subsides. For the Semont maneuver, the patient is seated upright in the middle of a stretcher. [merckmanuals.com]

  Overview Benign paroxysmal positional vertigo (BPPV) is one of the most common causes of vertigo — the sudden sensation that you're spinning or that the inside of your head is spinning. [mayoclinic.org]

  Benign paroxysmal positional vertigo, or BPPV, is a common cause of vertigo. This condition occurs when crystals move from one part of the inner ear to another, disrupting signals to the brain. [medicalnewstoday.com]

  What is benign paroxysmal positional vertigo? Benign positional vertigo, also known as positional vertigo or BPPV, is a common type of vertigo — a sudden sensation of spinning or swaying. [mercy.com]

• Aura

  Although an aura may signal a seizure only seconds before it occurs, an aura and a seizure may be separated by as much as an hour. [verywellhealth.com]

  […] interruption (e.g smelling a pleasant smell if the aura is a certain bad smell) may abort emotion-triggered seizures. [clumsylostmedicalstudent.wordpress.com]

  • No aura. • Usually last for only a few seconds. 5. • Accompanied by eye lid flutter or upward rolling of eyes. • Absence seizures can have simple automatisms like lip-smacking or picking at clothing. • Head can minimally fall forward. • No postictal [slideshare.net]

  These seizures are sometimes known as "warnings" or "auras" because they can be a sign that another type of seizure is about to happen. [nhs.uk]

Since absence seizures are characterized by lapses of awareness, by the patient staring off into space, differential diagnoses have to be excluded. Those may include metabolic disorders and intoxications. A detailed medical history may give initial indications regarding the nature of those staring spells. If metabolic anomalies or an intoxication are presumed, laboratory tests may be required to confirm or rule out this possibility.

In case of absence seizures, an EEG may be diagnostic and usually shows features characteristic of certain types of epilepsy. In order to produce these features, it may be helpful to provoke an absence seizure. Therefore, the patient may be stimulated with flickering lights or just asked to breathe rapidly. A thorough analysis of the EEG should be carried out to identify the precise type of epilepsy and maybe even its cause.

If an EEG does not yield conclusive results or if organic anomalies are suspected, a brain scan may be indicated. Magnetic resonance imaging (MRI) is the method of choice to detect malformations, neoplasias and other pathological structures that may cause epilepsy [13].

• 3-4 Hz Spikes

  Ictal EEG consisted of high amplitude generalised spike/multiple spike and slow waves at 3 Hz (fig 1). [adc.bmj.com]

  In electroencephalography (EEG), generalized 3-4 Hz spike and slow wave complexes indicate an absence seizure. Seizures are pyknoleptic in childhood absence epilepsy, i.e. they occur frequently up to several times a day, but only last a few seconds. [symptoma.com]

  Typical absence seizures have generalized 3-Hz spike-and-wave complexes (see image below). EEG of a typical absence seizure with 3-Hz spike-and-wave discharges. [emedicine.medscape.com]

• Occipital Intermittent Rhythmic Delta Activity

  Occipital intermittent rhythmic delta activity (OIRDA) may be seen in a third of children with childhood absence epilepsy, at a frequency of 2.5 to 4 Hz and may have a notched appearance. Caution. [medlink.com]

• EEG Seizure Activity

  Eighteen patients had “generalized EEG seizure activity” during the status, but 2 of them were finally diagnosed as suffering from focal epilepsy. [hindawi.com]

• Hypoglycemia

  Seizures can also occur in people who do not have epilepsy for various reasons including brain trauma, drug use, elevated body temperature, hypoglycemia (low blood sugar levels) and hypoxia (low levels of oxygen to the brain). [dbpedia.org]

  I would recommend reaging about Hypoglycemia / Low Blood Sugar! [circleofmoms.com]

  They may be genetic and are commonly provoked by severe metabolic upset (electrolyte disturbance, organ failure, hypoglycemia, hypoxia, sedative/alcohol withdrawal, etc). 22-4. Does epilepsy last a lifetime? 22-4. [dartmouth.edu]

  The acute causes include hypoglycemia (low blood sugar, hypocalcemia (low blood calcium), meningitis, bacterial toxins (such as shigella), alcohol withdrawal, environmental toxins, electrical shock, and side effects of medication. [childbrain.com]

Anti-epileptic treatment should aim at finding the appropiate dose for each individual requiring therapy. Here, the appropiate dose referes to a dose as high as necessary and as low as possible. Usually, treatment starts with a low dose that progressively increases until seizures are under control.

It is recommended to continue treatment until long after the last seizure, because relapses are frequent and often include tonic-clonic seizures. A seizure-free period of two years may justify therapy discontinuation, but decisions have to be taken on a case by case basis.

Absence seizures may be treated with the following drugs:

• Ethosuximide. This drug mediates its anticonvulsant effect by blocking low voltage-gated calcium channels. It is the drug of choice to treat absence seizures. Most patients respond well to this treatment [14].
• Valproate. In cases refractory to ethosuximide, valproate may be an alternative. It is, however, associated with a higher risk of birth defects in babies and should therefore be administered with caution to women.
• Lamotrigine. This anti-epileptic channel blocker may be less effective than ethosuximide and valproate, but has also fewer side effects [15].
• Zonisamide. This anticonvulsant has been recommended to treat typical absence seizures and refractory primary generalized epilepsy [16].
• Levetiracetam. Levetiracetam is a derivative of the nootropic piracetam and is indicated for JME [17]. It is currently being investigated for effectivity in CAE or JAE.
• Topiramate. Although this anticonvulsant has been used to treat generalized tonic-clonic seizures, data regarding its effect in absence epilepsy is rare [16]. It may be used as adjunctive therapy in cases of the Lennox-Gastaut syndrome. 

The distinct forms of absence epilepsy are associated with different prognoses. In general, young age at onset, physiological EEG background signals and satisfying response to therapy are good prognostic signals.

Patients suffering from CAE generally respond well to treatment and remission is possible. However, up to 40% of children diagnosed with CAE do develop tonic-clonic seizures. Should that be the case, chances for complete remission decrease.

Although the probability of ocurrence of tonic-clonic seizures is high in adolescents diagnosed with JME, they usually respond well to anti-epileptic treatment. Only few cases may be resolved by lifestyle adaptation (abstinence from alcohol, well controlled sleep regimen) and the majority of patients requires treatment for life because the relapse rate is >90% [11].

Epileptic seizures are triggered by abnormal or excessive electrical activity in the brain that is, in turn, caused by disorders in electrolyte and neurotransmitter balance [4]. Sometimes this abnormal electrical acitivity is compared to cerebral short circuits. In an EEG, seizures are often characterized by abnormal, repetitive patterns.

Generally, no direct triggers can be identified. It has been reported that hyperventilation may provoke an absence seizure. Also, genetic predisposition seems to play an important role, especially in children [5]. However, the majority of children suffering from absence seizures does overcome them when growing up. Of note, some children with absence seizures may also develop tonic-clonic seizures.

Epidemiological studies regarding absence seizures and those forms of epilepsy that may involve them are complicated by the existence of distinct classification systems.

Thus, the following data should merely provide orientation regarding the incidence of different forms of absence epilepsy. For children and adolescents younger than 18 years, studies conducted in the US showed that 4,000 cases of individuals with absence epilepsy and 1,500 individuals with JME were diagnosed each year [6]. 

Studies regarding the incidence of idiopathic generalized epilepsies have been carried out. In this context, an incidence of up to 8 per 100,000 inhabitants has been estimated for CAE [7]. Prevalence of CAE is highest in children aged 2 to 9 years and is of up to 0.7 per 1,000 persons. Girls are affected significantly more often than boys. With regards to JAE, less data is available. The disease is usually diagnosed in adolescents aged 10 to 17 years and its prevalence has been estimated to be about 0.1 per 100,000 persons [8]. JME is also diagnosed in adolescents, mainly in those aged 12 to 18 years, and the incidence is of approximately 1 per 100,000 inhabitants [7]. Thus, JME is diagnosed more frequently than JAE, but less often than CAE. Similar to CAE, females seem to be affected more often. The prevalence has been estimated to be up to 0.2 per 2,000 persons. It has been speculated that JME does occur less frequently in developing countries.

With regard to symptomatic generalized epilepsies, few data is available regarding epilepsies with myoclonic absences and the Lennox-Gastaut syndrome [9]. Interestingly, a male preponderance has been reported for epilepsies with myoclonic absences and the Lennox-Gastaut syndrome . The incidence of the Lennox-Gastaut syndrome has been estimated to be about 2 per 100,000 persons.

Current knowledge regarding pathophysiologic processes behind absence seizures is mainly derived from animal models. These animal models are based on a reverberating circuit generating abnormal, oscillating rhtyhms between cortex and thalamus. In an EEG, characteristic spike and wave complexes can be seen.

The reticulothalamic nucleus of the thalamus contains inhibitory gabaergic interneurons. Prolonged opening of the GABA-receptor is presumably associated with an increased influx of chloride ions and leads to hyperpolarization. Low voltage-gated calcium channels are active at such low membrane potentials, may cause rebound depolarization and trigger absence seizures. Indeed, absence seizures may be treated with ethosuximide, a drug blocking such calcium channels.

Because genetic predisposition does play an important role in the development of absence seizures, several studies have been carried out to identify those genes that contribute to idiopathic generalized epilepsies such as CAE, JAE and JME. Not surprisingly, genes that were proven to affect the incidence of idiopathic generalized epilepsies, encode for ion channels. Polymorphisms affecting the expression of GABA receptors and voltage-gated calcium channels may be responsible for CAE and JME. Furthermore, mutations in genes encoding voltage-gated chloride channels have been associated with CAE, JAE and JME. Certain types of absence epilepsies have been related to mutations affecting the expression of the neuronal nicotinic acetylcholine receptor and the GLUT1 glucose transporter [10].

No preventive strategies have been identified.

Patients suffering from in idiopathic or symptomatic generalized epilepsy may have absence seizures [1].

Childhood absence epilepsy (CAE), juvenile absence epilepsy (JAE) and juvenile myoclonic epilepsy (JME) are idiopathic generalized epilepsies that may involve typical absence seizures. In electroencephalography (EEG), generalized 3-4 Hz spike and slow wave complexes indicate an absence seizure. Seizures are pyknoleptic in childhood absence epilepsy, i.e. they occur frequently up to several times a day, but only last a few seconds. On the other hand, in epilepsies with later onset, absence seizures usually occur less often but last longer. They are therefore of non-pyknoleptic or spanioleptic nature. Myoclonic and tonic-clonic seizures may be associated with these idiopathic generalized epilepsies, but are seldom observed in forms with an early onset.

Contrary to idiopathic generalized epilepsies, absence seizures in symptomatic generalized epilepsies are represented by 1.5-2-5 Hz slow spike and wave complexes [2]. They are therefore termed atypical absence seizures. Since these absence seizures may involve decrease or increase of muscle tone, patients may fall during a seizure.

According to the recommendations of the International League Against Epilepsy, absence seizures are now classified as typical, atypical or special, whereby absence seizures with special features include myoclonus [3].

Absence seizures are associated with certain forms of epilepsy. They generally last only a few seconds and do involve brief periods of time when an indicidual lapses out of awareness. They are most frequently observed in children.

Causes

While some genetic variants have been identified that contribute to the development of absence seizures, no direct causes could be determined so far. It has been proposed that flickering lights and rapid breathing may trigger an absence seizure, but that may be limited to genetically predisposed persons.

Some types of epilepsy associated with absence seizures mainly affect young children, whereas others are more frequently observed in adolescents. Depending on the exact type of epilepsy, further symptoms may be present.

Symptomps

The person suffering an absence seizure usually interrupts what they are doing, stares into space and resumes his or her activities after some seconds. During the seizure, the patient neither speaks nor responds to their surroundings. In some cases, the affected person blinks rapidly.

Absence seizures are typically not associated with changes in muscle tone, although these may be the case in certain forms of epilepsy. Also, absence seizures may be accompanied by myoclonic or tonic-clonic seizures that involve twitching and jerking.

Diagnosis

Because absence seizures mainly affect children, they are sometimes simply referred to as staring spells or wandering attention. It is not uncommon for parents or teachers to attribute them to child behavior rather than to a medical problem like epilepsy.

A detailed medical history may therefore be given if a physician is consulted. While blood tests may be conducted to rule out other causes for the observed brief losses of awareness, an EEG is usually diagnostic for epilepsy. In an EEG, the brain's electrical activity is recorded. In cases of epilepsy, these recordings show specific alterations. If needed, a brain scan may be carried out for further diagnostics.

Treatment

Because absence seizures may impair the patient's ability to partake in day-to-day activities, school or even work, they should be treated with anti-epileptic drugs. Ethosuximide, valproate and lamotrigine are only some of the currently available alternatives. Most people suffering from absence seizures respond well to treatment. It may be necessary to take more than one drug if other types of seizures are experienced.

An anti-epileptic therapy is usually a long-term treatment that should be continued even if the patient has been seizure-free for some time. The decision to discontinue treatment should be taken by the physician, not by the patient.

1. Proposal for revised classification of epilepsies and epileptic syndromes. Commission on Classification and Terminology of the International League Against Epilepsy. Epilepsia. 1989; 30(4):389-99.
2. Benbadis SR, Berkovic SF. Absence Seizures. In: Wyllie E, ed. The Treatment of Epilepsy. Principles and Practice. Vol 4. Philadelphia, PA: Lippincott, Williams and Wilkins; 2006:305-315.
3. Berg AT, Berkovic SF, Brodie MJ, et al. Revised terminology and concepts for organization of seizures and epilepsies: Report of the ILAE Commission on Classification and Terminology, 2005-2009. Epilepsia. 2010; 51(4):676-685.
4. Panayiotopoulos CP. Absence epilepsies. In: Engel J Jr, Pedley TA, eds. Epilepsy: A Comprehensive Textbook. Philadelphia, PA: Lippincott-Raven; 1997:2327-46.
5. Lu Y, Wang X. Genes associated with idiopathic epilepsies: a current overview. Neurol Res. 2009; 31:135-143.
6.  Hauser WA. The prevalence and incidence of convulsive disorders in children. Epilepsia. 1994; 35(suppl 2):S1-S6.
7. Joensen P. Prevalence, incidence, and classification of epilepsy in the Faroes. Acta Neurol Scand. 1986; 74:150-155.
8. Sidenvall R, Forsgren L, Blomquist HK, Heijbel J. A community-based prospective incidence study of epileptic seizures in children. Acta Paediatr. 1993; 82(1):60-65.
9. Bureau M, Tassinari CA. Epilepsy with myoclonic absences. Brain Dev. 2005; 27:178-184.
10. Mullen SA, Suls A, De Jonghe P, Berkovic SF, Scheffer IE. Absence epilepsies with widely variable onset are a key feature of familial GLUT1 deficiency. Neurology. 2010; 75(5):432-440.
11. Delgado-Escueta AV, Enrile-Bacsal F. Juvenile myoclonic epilepsy of Janz. Neurology. 1984; 34(3):285-94.
12. Sadleir LG, Scheffer IE, Smith S, Connolly MB, Farrell K. Automatisms in absence seizures in children with idiopathic generalized epilepsy. Arch Neurol. 2009; 66(6):729-734.
13. Betting LE, Mory SB, Lopes-Cendes I, et al. MRI reveals structural abnormalities in patients with idiopathic generalized epilepsy. Neurology. 2006; 67(5):848-852.
14. Posner EB, Mohamed K, Marson AG. Ethosuximide, sodium valproate or lamotrigine for absence seizures in children and adolescents. Cochrane Database Syst Rev. 2005; (4):CD003032.
15. Glauser TA, Cnaan A, Shinnar S, et al. Ethosuximide, valproic acid, and lamotrigine in childhood absence epilepsy. N Engl J Med. 2010; 362(9):790-799.
16. Bergey GK. Evidence-based treatment of idiopathic generalized epilepsies with new antiepileptic drugs. Epilepsia. 2005; 46(suppl 9):S161-S168.
17. Glauser T, Ben-Menachem E, Bourgeois B, et al. Updated ILAE evidence review of antiepileptic drug efficacy and effectiveness as initial monotherapy for epileptic seizures and syndromes. Epilepsia. 2013; 54(3):551-563.