Seizure causes

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Causes

Overview

Some medications produce an increased risk of seizures and electroconvulsive therapy (ECT) deliberately sets out to induce a seizure for the treatment of major depression. Many seizures have unknown causes.

Seizures which are provoked are not associated with epilepsy, and people who experience such seizures are normally not diagnosed with epilepsy. However, the seizures described above resemble those of epilepsy both outwardly, and on EEG testing.

Seizures can occur after a subject witnesses a traumatic event. This type of seizure is known as a psychogenic non-epileptic seizure and is related to post-traumatic stress disorder.

A seizure trigger is a factor that can cause a seizure in a person who either has epilepsy or does not. There are many known causes of seizures, and in some patients, it is possible to determine what triggers seizures in general or has led to the onset of a particular seizure. But the factors that lead to a seizure are often so complex that it is not usually possible in all patients to determine what causes a particular seizure, what causes it to happen at a particular time, or how often seizures occur.

Common Causes

• Brain damage from prenatal or perinatal injuries
• Congenital abnormalities or genetic conditions with associated brain malformations
• A severe blow to the head
• A stroke that starves the brain of oxygen
• An infection of the brain such as meningitis, encephalitis, neurocysticercosis
• Certain genetic syndromes
• A brain tumor

Causes by Organ System

Cardiovascular	No underlying causes
Chemical/Poisoning	No underlying causes
Dental	No underlying causes
Dermatologic	No underlying causes
Drug Side Effect	No underlying causes
Ear Nose Throat	No underlying causes
Endocrine	No underlying causes
Environmental	No underlying causes
Gastroenterologic	No underlying causes
Genetic	No underlying causes
Hematologic	No underlying causes
Iatrogenic	No underlying causes
Infectious Disease	No underlying causes
Musculoskeletal/Orthopedic	No underlying causes
Neurologic	No underlying causes
Nutritional/Metabolic	No underlying causes
Obstetric/Gynecologic	No underlying causes
Oncologic	o underlying causes
Ophthalmologic	No underlying causes
Overdose/Toxicity	No underlying causes
Psychiatric	No underlying causes
Pulmonary	No underlying causes
Renal/Electrolyte	No underlying causes
Rheumatology/Immunology/Allergy	No underlying causes
Sexual	No underlying causes
Trauma	No underlying causes
Urologic	No underlying causes
Miscellaneous	No underlying causes

Causes in Alphabetical Order

17-beta-hydroxysteroid dehydrogenase X deficiency 2-Hydroxyglutaricaciduria 2-methylbutyryl-coenzyme A dehydrogenase deficiency 22Q11 microdeletion 4-Aminopyridine 6-Pyruvoyl tetrahydropterin synthase deficiency Absence seizure Acute disseminated encephalomyelitis Acute intermittent porphyria Acute neonatal encephalopathy Acute seizures Acute stroke Acyclovir Adenylosuccinate lyase deficiency ADNFLE mutation Aicardi Goutieres syndrome Aicardi syndrome Alcohol withdrawal Alexander disease Alkalosis Almotriptan Alpers disease Alpha-L-iduronidase deficiency Alpha-methylacyl-CoA racemase deficiency Alprazolam Aluminium toxicity Alveolar Hydatid Disease Alzheimer's Disease Amifampridine Aminomethyltransferase deficiency Aminophylline Amitriptyline Amoxapine Amphetamines Amphetamines Amphotericin B Ampicillin Angelman syndrome Anticholinergics Antihistamines Antimalarials Aqueous iodinated contrast agents Arabinoside Arginase deficiency Arginine:glycine amidinotransferase deficiency Arginosuccinate synthetase deficiency Aripiprazole Arrythmias Arterial ischemic stroke Arteriovenous malformation ARX (Aristaless-related homeobox) mutations Ascariasis Asphyxiation Astrocytoma Atenolol Athabaskan brain stem dysgenesis Atomoxetine Atonic seizure Atorvastatin ATP6V0A2-related cutis laxa Autism Autoimmune conditions Autonomic seizure Autosomal dominant conditions Autosomal dominant lateral temporal Autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) Autosomal recessive conditions Azathioprine Baclofen Barakat syndrome Battaglia Neri syndrome Belgian type mental retardation Belgian type Mental retardation syndrome, Benign (childhood) epilepsy with centrotemporal spikes Benign childhood occipital seizures Benign familial infantile convulsions Benign familial infantile epilepsy Benign familial neonatal convulsions Benign familial neonatal seizure Benign familial neonatal seizures Benign infantile familial convulsions Benign neonatal convulsions Benign neonatal epilepsy Benign occipital epilepsy of childhood (Gastaut syndrome) Benign partial epilepsy in infancy Benign Rolandic epilepsy Benzene hexachloride Benztropine Besnier-Boeck-Schaumann disease Bicuculline Bifunctional peroxisomal enzyme deficiency Binaural beat brainwave entrainment Biochemical abnormalities Birth hypoxia Borjeson-Forssman-Lehmann syndrome Brachydactyly-mental retardation syndrome Brain abscess Brain cancer Brain hemorrhage Brain injury Brain tumor Breath-holding spells Bromocriptine Bupivacaine Bupivicaine Bupropion Buspirone Busulfan Butyrophenones Cabergoline CADASIL Caffeine Captopril Carbamoylphosphate synthetase deficiency Carbenicillin Carbohydrate deficiency glycoprotein syndrome Carbohydrate deficient glycoprotein syndrome Carbon monoxide toxicity Carbon tetrachloride Carbonmonoxide poisoning Cardiac and vascular conditions Cardiac failure Carisoprodol Carmustine Carnitine-acylcarnitine translocase deficiency Carotid Sinus Syndrome Carvedilol Catamenial epilepsy Cavernoma Cavernous haemangioma Cefepime Cefixime Cefotetan Ceftazidime Cefuroxime Central nervous system infection Cephalexin Cephalosporine Cephalosporins Cerebellar dyssynergia Cerebral Aneurysm Cerebral dysgenesis Cerebral dysgenesis associated with inborn errors of metabolism Cerebral infarction Cerebral Palsy Cerebral venous sinus thrombosis Cerebrovascular disease Cerebrovascular etiologies Ceroid lipofuscinosis Chemicals Chester porphyria Childbirth trauma Chlorambucil Chloroquine Chlorpromazine Cholestanol storage disease Christianson syndrome Chromosomal abnormalities Chromosomal anomalies Chromosome 12p tetrasomy syndrome Chromosome 14 ring syndrome Chromosome 15q triplication syndrome Chromosome 15q13.3 microdeletion syndrome Chromosome 17q21.31 deletion syndrome Chromosome 20 ring Chromosome 20 ring syndrome Chromosome 4p trisomy Chromosome 7q deletion syndrome Chromosome 9q deletion syndrome Chronic Renal Failure Cilastatin/imipenem Ciprofloxacin Cisplatinum Citalopram CK syndrome Clomiphene Clomipramine Clonazepam Clonic seizures Clorazepate Clozapine Cocaine Cocaine) Combined malonic and methylmalonic Concussion Congenital abnormalities of the brain Congenital conditions Congenital heart disease Congenital muscular dystrophy Coproporphyria, hereditary Cornelia de Lange syndrome 2 Corpus callosum hypoplasia Cortical dysplasia Craniodiaphyseal dysplasia Craniofacial dysmorphism-polysyndactyly syndrome Creatine deficiency syndrome Creutzfeldt-Jakob Disease Crome syndrome Cryptogenic Cyanides Cyclobenzaprine Cyclophosphamide Cycloserine Cyclosporin Cyclosporine Cystathionine beta-synthase deficiency Cysticercosis Cytomegalovirus Cytosine D-2-hydroxyglutarate dehydrogenase deficiency D-glycerate kinase deficiency Dandy-Walker syndrome Dantrolene Deafness -- congenital onychodystrophy Degenerative disease Dementia DEND syndrome Dentatorubropallidoluysian degeneration Desipramine Dexmethylphenidate Dextroamphetamine Dialysis disequilibrium syndrome Diazepam Dicyclomine Dihydropteridine reductase deficiency Dihydropyrimidine dehydrogenase deficiency Diomedi-Bernardi-Placidi syndrome Diphenhydramine Diphenydramine Disopyramide Domperidone Donepezil Doripenem Dothiepin Double cortex syndrome Down's Syndrome Doxepin Doxorubicin Dronabinol

DTP vaccine Duloxetine Dyke-Davidoff-Masson syndrome Dysmorphism-hypogonadism-diabetes complex Early infantile epileptic encephalopathy Early myoclonic encephalopathy East Syndrome EBN1 mutation EBN2 mutation Eclampsia Efavirenz Embolism Encephalitis Endometriosis Enflurane Enfluraneketamine Entacapone Ephedrine Epidermal nevus syndrome Epidural haemorrhage Epilepsy-mental deterioration Epilepsy-microcephaly-skeletal dysplasia Epileptic encephalopathy Episodic ataxia Epoetin Ergonovine Erythropoietin Escitalopram Estazolam Estrogen Eszopiclone Etoposide Extracorporeal membrane oxygenation Familial Encephalopathy with neuroserpin inclusion bodies Familial Febrile Convulsions Familial infantile convulsions/paroxysmal choreoathetosis Familial porencephaly Fat embolism Fatty acid hydroxylase-associated neurodegeneration Febrile convulsion Febrile Seizures Febrile seizures in children Feigenbaum-Bergeron-Richardson syndrome Fentanyl Fever Flickering or flashing lights Flumazenil Fluoxetine Fluphenazine Flurazepam Fluvastatin Flynn-Aird syndrome Focal cortical dysplasia Folate malabsorption, hereditary Folic acid Folic acid in large amounts Foscarnet Fructose-1-phosphate aldolase deficiency Fryns-Aftimos syndrome Fucosidosis Fukuyama congenital muscular dystrophy Fukuyama type muscular dystrophy Fumarate hydratase deficiency Gabapentin Galactosialidosis Gamma hydroxybutyrate Gamma-aminobutyrate transaminase deficiency Ganciclovir Gangliosidosis Gaucher's Disease GEFS+ mutation Gemifloxacin Generalized epilepsy with febrile seizures plus Genetic conditions German measles Giant arteriovenous malformation Giant axonal neuropathy Ginkgo biloba Glatiramer Glucose transporter type 1 Glutamate decarboxylase deficiency Glutathione synthase deficiency Glycerol kinase deficiency Glycine decarboxylase deficiency Glycogen storage diseases Griscelli syndrome type 2 Guanidinoacetate methyltransferase deficiency Gurrieri-Sammito-Bellussi syndrome Gynaecologic conditions Haloperidol Haloperiodol Hartnup disease Haw River syndrome Head injury Head trauma Heat stroke Helminths and helminthic conditions hemimegalencephaly Hepatic failure Hippocampal sclerosis Hischsprung disease-microcephaly-mental retardation syndrome HIV Huntington's Chorea Hydroxyacyl-coa dehydrogenase deficiency Hydroxyzine Hyperbaric oxygen Hyperglycemia Hypernatremia Hyperornithinaemia-hyperammonaemia-homocitrullinuria syndrome Hypertensive encephalopathy Hyperthyroidism Hyperventilation Hypocalcemia Hypoglycemia Hypomagnesemia Hypomelanosis of Ito Hyponatremia Hypoparathyroidism Hypophosphatemia Hypotension Hypothalamic-pituitary insufficiency Hypothyroidism Hypovolemia Hypoxia Hypoxic encephalopathy Hypoxic-ischemic encephalopathy Imipenem Incontinentia pigmenti (Bloch Sulzberger syndrome) Indomethacin Infant epilepsy with migrant focal crisis Infantile neuroaxonal dystrophy Infantile-onset spinocerebellar ataxia Insulin Interferon beta-1a Interferon beta-1b Intoxication Intoxication with drugs Intracerebral Intracranial abscess or granuloma Intracranial arteriovenous malformation Intracranial hemorrhage Intracranial space-occupying lesion Intraventricular haemorrhage Isoniazid Isotretinoin Ivermectin KCNJ11-related permanent neonatal diabetes Kernicterus Ketamine Ketorolac Kidney failure Kohlschutter syndrome Kohlschutter-Tonz syndrome L-2-hydroxyglutarate dehydrogenase deficiency Lafora body disease LAMA2-related muscular dystrophy Landau-Kleffner syndrome Lead poisoning Lennox-Gastaut syndrome Levofloxacin Lidocaine Lindane Linear sebaceous nevus Linezolid Lipoid proteinosis of Urbach and Wiethe lissencephaly Lissencephaly with cerebellar hypoplasia Lithium Local anesthetics Lomefloxacin Lorazepam Loxapine Lupus erythematosus Malaria Malignant hypertension Malonyl-CoA decarboxylase deficiency Maple syrup urine disease Maprotiline McDowall syndrome McLeod neuroacanthocytosis syndrome MECP2 duplication syndrome Mefenamic acid Mefloquine MELAS syndrome Memantine Meningioma Meningitis Meningoencephalitis Menkes disease Meperidine Mephobarbital Meropenem MERRF syndrome Metabolic encephalopathy Methionine malabsorption Methocarbamol Methohexital Methotrexate Methylenetetrahydrofolate reductase deficiency Methylphenidate Methylxanthines Metronidazole Mexiletine Mianserin Microcephaly Microcephaly-mental retardation-spasticity-epilepsy complex Microcephaly-pontocerebellar hypoplasia-dyskinesia complex Microphthalmia-dermal aplasia-sclerocornea syndrome Migraine Migrating partial seizures of infancy Miller-Dieker syndrome Mirtazapine Missed dose Mitochondrial aspartyl-tRNA synthetase deficiency Mitochondrial complex III deficiency Mitochondrial DNA depletion syndrome Mitoxantrone MMR vaccine Modafinil Molindone Monosomy 1p36 syndrome Montelukast Movement disorders Mowat-Wilson syndrome Moxifloxacin Mucolipidosis II alpha/beta Multiple sclerosis Muscle-eye-brain disease Mycophenolate Myoclonic progressive familial epilepsy Myoclonus progressive epilepsy of Unverricht and Lundborg Nalidixic acid Nasu-Hakola disease Navajo neurohepatopathy Neonatal hypoglycemia Neurocutaneous syndromes Neurocysticercosis

Neurodegenerative disorders Neurodevelopmental lesions Neuroectodermal melanolysosomal disease Neurofibromatosis type 1 Neurosyphilis Nicolaides-Baraitser syndrome Night terrors Nikethamide Nocturnal frontal lobe epilepsy Nomifensine Nonketotic hyperglycemia Norfloxacin Nortriptyline Oculocerebrocutaneous syndrome OFD syndrome type IX Ofloxacin Ohtahara syndrome Olanzapine Ondansetron Onychodystrophy Organic acidemia Ornithine carbamyltransferase deficiency Orthostatic hypotension Oxacillin Oxybutynin Oxycodone Oxymorphone Oxytocin Panayiotopoulos syndrome Panic attack Pantothenate kinase associated neurodegeneration Paragonimiasis Paraneoplastic limbic encephalitis Paroxetine Paroxysmal dyskinesia Parry-Romberg syndrome Partington X-linked mental retardation Pediatric apnea PEHO syndrome Pellagra Penicillins Pentazocine Perinatal hypoxia or trauma Perisylvian syndrome Peroxisomal acyl-CoA oxidase deficiency Peroxisomal disorders Perphenazine Phencyclidine Phenobarbital Phenothiazines Phenylketonuria Phenylpropanolamine Phosphoethanolaminuria Photosensitive epilepsy Pick's Disease Pimozide Pitt-Hopkins syndrome Polyarteritis nodosa Pontocerebellar hypoplasia type 1 Pontocerebellar hypoplasia type 2a Pontocerebellar hypoplasia with infantile spinal muscular atrophy Porencephaly type 1 Porphobilinogen synthase deficiency Porphyria Posterior leucoencephalopathy syndrome Pramipexole Prednisone Presenile dementia Primidone Procainamide Procaine Procaine Prochlorperazine Promethazine Propoxyphene Propoxyphene Propoxyphene) Propranolol Protriptyline Pyridoxine deficiency Pyridoxine-5'-phosphate oxidase deficiency Pyridoxine-dependent epilepsy Pyrimethamine Pyruvate carboxylase deficiency Pyruvate dehydrogenase deficiency Quetiapine Rabies Ramelteon Ramon syndrome Ramsay Hunt syndrome Rasagiline Rasmussen encephalitis Recessive deafness-onychodystrophy-osteodystrophy-retardation syndrome Renal failure Renier-Gabreels-Jasper syndrome Respiratory failure Retinitis pigmentosa-polyneuropathy-epilepsy complex Rett syndrome Reversible posterior leukoencephalopathy syndrome Reye's Syndrome Rhinophyma Rhizomelic chondrodysplasia punctata Risperidone Rivastigmine Romano-Ward syndrome Ropinirole Rubinstein-Taybi syndrome Rud syndrome Salla disease Sandhoff disease Sanjad-Sakati syndrome Sarcoidosis Schaefer-Stein-Oshman syndrome Schistosoma japonicum Schistosomiasis Schizencephaly Seemanova-Lesny syndrome Selegiline Serotonin reuptake inhibitors Sertraline SeSAME syndrome Severe myoclonic epilepsy in Short chain acyl-CoA dehydrogenase Sialidosis type 1 Sibutramine Sickle cell crisis Sildenafil Sinovenous thrombosis Sjogren-Larsson syndrome Sleep deprivation Sleep disorders Sodium oxydate Sotos syndrome Space occupying lesion of the brain Spastic tetraplegic Sphingomyelinase deficiency Spinocerebellar ataxia 13 Stokes-Adams Syndrome Stress Stroke Structural lesions Strychnine Sturge-Weber syndrome Subarachnoid Subdural Subdural haemorrhage Subependymal nodular heterotopia Succinic semialdehyde dehydrogenase deficiency Succinyl-CoA synthetase deficiency Sudanophilic cerebral sclerosis Sulphite oxidase deficiency Sumatriptan Syncope Syphilis Systemic lupus erythematosus Tacrine Tacrolimus Tadalafil Takayasu arteritis Temazepam Temozolomide Temporal lobe epilepsy Terbutaline Tetany Thalidomide Thebaine Theophylline Thioridazine Thiothixene Thrombophlebitis Thrombosis Thrombotic thrombocytopenic purpura Tiagabine Ticarcillin Ticlopidine Tinidazole Tizanidine Tolcapone Tolterodine Tonic seizure Tonic-Clonic seizure TORCH syndromes Torsemide Toxoplasma, congenital Toxoplasmosis Tramadol Transient Ischemic Attack Tranylcypromine Trauma Triazolam Tricyclic antidepressants Trifluoperazine Trihexyphenidyl Trypanosomiasis Tuberous sclerosis Tyrosinaemia type 2 Unverricht-Lundborg syndrome Urea cycle disorders Uremia Valacyclovir Valsartan Valvular heart disease Van der Knaap disease Vardenafil Vasovagal syncope Vein of Galen malformation Venlafaxine Verapamil Vertebrobasilar dolichoectasia Vincristine Viruses and viral conditions Vitamin B1 deficiency (Thiamine deficiency) Vitamin B12 depletion (Pyridoxine deficiency) Von Hippel-Lindau Syndrome Walker-Warburg syndrome Water hemlock poisoning West syndrome Withdrawal from drugs Wittwer sydnrome Worster-Drought syndrome X-linked Hamel type Neurodegenerative syndrome X-linked Hypoparathyroidism X-linked inherited conditions X-linked Lissencephaly X-linked mental retardation X-linked Mental retardation syndromic due to JARID1C mutation X-linked periventricular heterotopia X-linked Wittwer type Mental retardation Zaleplon Zanamivir Zellweger spectrum Ziconotide Zidovudine Ziprasidone Zolpidem Zunich neuroectodermal syndrome

Secondary seizures

• Hypoxia
• Metabolic abnormalities
• Infection
• Cerebrovascular etiologies
• Drug effects, withdrawal, intoxication
• Hypoxic-ischemic encephalopathy
• Febrile seizures in children
• Structural lesions
• Inborn errors of metabolism

Nonepileptic seizures

• Disorders of sugar metabolism
• Organic acidemias
• Glycogen storage diseases
• Disorders of amino acid metabolism
• Urea cycle disorders
• Peroxisomal disorders
• Mitochondrial disorders
• Rasmussen's encephalitis

Unprovoked seizures

Unprovoked seizures are often associated with epilepsy and related seizure disorders.

Provoked seizures

• Arteriovenous malformation (AVM) is a treatable medical condition that can cause seizures, headaches, and brain hemorrhages. An MRI can quickly confirm or reject this as a cause.
• Head injury
• Intoxication with drugs
• Drug toxicity, for example aminophylline or local anesthetics
• Normal doses of certain drugs that lower the seizure threshold, such as tricyclic antidepressants
• Infection, such as encephalitis or meningitis
• Fever leading to febrile convulsions (but see above)
• Metabolic disturbances, such as hypoglycaemia, hyponatremia or hypoxia
• Withdrawal from drugs (anticonvulsants and sedatives such as alcohol, barbiturates, and benzodiazepines)
• Space-occupying lesions in the brain (abscesses, tumors)
• Seizures during (or shortly after) pregnancy can be a sign of eclampsia.
• Binaural beat brainwave entrainment may trigger seizures in both epileptics and non-epileptics
• Stroke may cause seizures, with embolic strokes more likely to present with seizures; cerebral venous sinus thrombosis, a rare type of stroke, is more likely to be accompanied by seizures than other types of stroke
• Multiple sclerosis sufferers may rarely experience seizures

Triggers

Alcohol consumption

There are varying opinions on the likelihood of alcoholic beverages triggering a seizure. Consuming alcohol may temporarily reduce the likelihood of a seizure immediately following consumption. But after the blood alcohol content has dropped, chances may increase. This may occur, even in non-epileptics.

Heavy drinking in particular has been shown to possibly have some effect on seizures in epileptics. But studies have not found light drinking to increase the likelihood of having a seizure at all. EEGs taken of patients immediately following light alcohol consumption have not revealed any increase in seizure activity.

Consuming alcohol with food is less likely to trigger a seizure than consuming it without.

Consuming alcohol while using many anticonvulsants may reduce the likelihood of the medication working properly. In some cases, it may actually trigger a seizure. Depending on the medication, the effects vary.

Alcohol withdrawal

Alcohol withdrawal is also responsible for seizures. This risk increases with each additional drink from which one has withdrawn.

Caffeine

Caffeine use can increase the occurrence of seizures, particularly if it interrupts normal sleep patterns.

Diet

Diet can play a role in a seizure occurring, and therefore, diet control in some cases can be used to prevent seizures. It is not known exactly what nutrients or lack thereof may contribute to or prevent a seizure. However, the ketogenic diet is practiced by some in order to control seizures.

Diseases

Those with various medical conditions may suffer seizures as one of their symptoms. These include:

• Arteriovenous malformation
• Brain abscess
• Brain tumor
• Cavernoma
• Eclampsia
• Encephalitis
• Meningitis
• Multiple sclerosis
• Systemic lupus erythematosus

Drugs

Some drugs may lower the seizure threshold when used doses intended for recreation. Drugs such as tramadol and methamphetamine have been noted to induce seizures in some, especially when used for long periods of time or in combination with other stimulants. Some drugs may reduce the risk of a seizure occurring. Withdrawals from drugs that act on the GABA receptors may lead to grand-mal seizures in people who have been heavily abusing drugs from the barbiturate or benzodiazepine families.

Fever

Main article: Febrile seizure

In children under the age of 5, fever of 102°F (39°C) or higher can lead to a seizure (usually tonic-clonic) known as a febrile seizure.

About 2-5% of all children will experience such a seizure during their childhood. Most of these children will also have some pre-existing neurological problem.

In most cases, a febrile seizure will not lead to epilepsy. But 30-40% of children who experience a febrile seizure will have more seizures in the future.

In adults and older children with epilepsy, illnesses with fever can be responsible for a seizure due to the stress that they cause. Additionally, in some patients, gastroenteritis, which causes vomiting and diarrhea, can lead to diminished absorption of anticonvulsants, thereby reducing protection against seizures.

Flickering or flashing lights

Main article: photosensitive epilepsy

In some epileptics, flickering or flashing lights, such as strobe lights, can be responsible for the onset of a tonic clonic, absence, or myoclonic seizure. This condition is known as photosensitive epilepsy, and in some cases, the seizures can be triggered by activities that are harmless to others, such as watching television or playing video games, or by driving or riding during daylight along a road with spaced trees, thereby simulating the "flashing light" effect. Some people can suffer a seizure as a result of blinking one's own eyes. Contrary to popular belief, this form of epilepsy is relatively uncommon, accounting for just 3% of all cases. In all other epileptics, such lights are no more capable of triggering a seizure than in a non-epileptic person.

A routine part of the EEG test involves exposing the patient to flickering lights in order to attempt to induce a seizure, to determine if such lights may be triggering a seizure in the patient, and to be able to read the wavelengths when such a seizure occurs.

Head Injury

A severe head injury, such as one suffered in a motor vehicle accident, fall, assault, or sports injury, can result in one or more seizures that can occur immediately after the fact or up to a significant amount of time later. This could be hours, days, or even years following the injury.

A brain injury can cause seizure(s) because of the unusual amount of energy that is discharged across of the brain when the injury occurs and thereafter. When there is damage to the temporal lobe of the brain, there is a disruption of the supply of oxygen.

The risk of seizure(s) from a closed head injury is about 15%. In some cases, a patient who has suffered a head injury is given anticonvulsants, even if no seizures have occurred, as a precaution to prevent them in the future.

Menstrual Cycle

See Catamenial epilepsy

Other medications

Seizures may be a side effect of certain drugs, though with most, the effect is quite rare, and for most patients, they are safe. These include:

• Aminophylline
• Bupivicaine
• Bupropion
• Butyrophenones
• Chlorambucil
• Clozapine
• Enfluraneketamine
• Estrogen
• Fentanyl
• Insulin
• Lidocaine
• Meperidine
• Pentazocine
• Phenothiazines
• Prednisone
• Procaine
• Propoxyphene
• Theophylline
• Tramadol
• Tricyclic antidepressant
• The following antibiotics: Isoniazid, Lindane, Metronidazole, Nalidixic acid, and Penicillin, though Vitamin B6 taken along with them may prevent seizures
• Vitamin B1 deficiency (Thiamine deficiency) was reported to cause seizures, especially in alcoholics
• Vitamin B12 depletion (Pyridoxine deficiency) was reported to be associated with pyridoxine-dependent seizures.
• Folic acid in large amounts was considered that might counteract the antiseizure effects of antiepileptic drugs and increase the seizure frequency in some children, although that concern is no longer held by epileptologists.

Sudden withdrawal from anticonvulsants may lead to seizures. It is for this reason that if a patient's medication is changed, the patient will be weaned from the medication being discontinued following the start of a new medication.

Use of certain street drugs may also lead to seizures. These include amphetamines, cocaine, methylphenidate, and phenylpropanolamine (not all of the drugs pictured).

If treated with the wrong kind medication antiepileptic drugs (AED), seizures may increase, as most AEDs are developed to treat a particular type of seizure.

Missed dose

A missed dose or incorrectly timed dose of an anticonvulsant may be responsible for a breakthrough seizure, even if the patient has often missed doses in the past, and has not suffered a seizure as a result of the missed dose. Missed doses are one of the most common reasons for a breakthrough seizure. Even a single missed dose is capable of triggering a seizure in some patients. This is true, even when the patient has not suffered a seizure after previously missing much more of his/her medication. Doubling the next dose does not necessarily help.

Missed doses can occur as a result of the patient's forgetfulness, unplanned lack of access to the medication, difficulty in affording the medication, or self-rationing of the medication when one's supply is low, among other causes.

Sleep deprivation

Sleep deprivation is the second most common trigger of seizures. In some cases, it has been responsible for the only seizure a person ever suffers. However, the reason for which sleep deprivation can trigger a seizure is unknown. One possible thought is that the amount of sleep one gets affects the amount of electrical activity in one's brain.

Patients who are scheduled for an EEG test are asked to deprive themselves of some sleep the night before in order to be able to determine if sleep deprivation may be responsible for seizures.

In some cases, patients with epilepsy are advised to sleep 6-7 consecutive hours as opposed to broken-up sleep (e.g. 6 hours at night and a 2-hour nap) and to avoid caffeine and sleeping pills in order to prevent seizures.

Stress

In one study, emotional stress was reported by 30-60% prior to their seizures, thereby being the leading cause. This may include stress over hard work one is trying to accomplish, one's obligations in life, worries, emotional problems, frustration, anger, anxiety, or many other problems.

Stress may trigger a seizure because it affects the hormone cortisol. Stress can also affect the part of the brain that regulates emotion. Although stress can alter levels of these hormones, it remains unclear whether or not stress can directly result in an increase in seizure frequency.

See also

• Breakthrough seizure