Table of Contents
Epilepsy is a neurological disorder characterized by sudden recurrent episodes of sensory disturbance, loss of consciousness, or convulsions, associated with abnormal electrical activity in the brain.
Epilepsy is not a disease but rather a symptom of abnormal brain activity. It can result from many different causes, including head trauma, stroke and certain infectious diseases.
Symptoms vary depending on the type of seizure. Generalized seizures are caused by abnormal electrical activity on both sides of the brain. Focal seizures occur when abnormal activity is limited to one side of the brain.
Epilepsy can be the result of many different situations or conditions, including:
- Stroke
- Traumatic brain injury
- Severe infections
- Brain tumors
- Brain surgery
- Dementia (such as Alzheimer’s disease)
- Genetic disorders
- Neonatal hypoxic-ischemic encephalopathy (neonatal HIE)
Focal Seizures
During a focal seizure, abnormal electrical activity occurs in one part of the brain. These seizures usually don’t involve a loss of consciousness, but they may affect your awareness, movement or emotions.
Seizures that begin in one side of your brain may cause symptoms on opposite sides of your body. For example, if you have a seizure affecting the left side of your brain, the symptoms may appear on your right side. This is because nerve signals are transmitted from your brain to specific parts of your body through nerves connected on the opposite sides of your brain and spinal cord.
Focal seizures may progress to generalized seizures, which affect both sides of your brain and typically include a loss of consciousness.
Temporal Lobe Seizures
Temporal lobe seizures are the most common type of seizure that affect adults. They are a form of complex partial seizures that may be caused by epilepsy or other medical conditions.
In temporal lobe seizures, one or both temporal lobes of your brain are affected. The temporal lobe is located on the sides of your brain just above your ears. It’s responsible for many aspects of processing, including:
- Hearing
- Speech
- Learning and memory
The temporal lobes also play an important role in understanding language, regulating emotions and processing visual information.
The signs of temporal lobe seizures can vary widely between people, and even from one seizure to another in the same person.
Frontal Lobe Seizures
- Sudden emotional changes (such as fear, rage, crying)
- Sudden sense of déjà vu (familiarity) or jamais vu (unfamiliarity), or feelings that events are “not real”
- Numbness, tingling, or strange tastes or smells
- Altered vision
- Hearing noises or songs
- Temporary paralysis
Occipital Lobe Seizures
Occipital Lobe Seizures, also called Epilepsy, is a neurological condition (meaning it has to do with the brain) that manifests in the form of seizures. These seizures are usually triggered by specific stimuli, which can vary from person to person. The most common triggers for Occipital Lobe Seizures are flickering lights and flashing lights.
It’s important to note that these seizures can be controlled through medications like Phenobarbital, which is an anticonvulsant used to treat epilepsy. It’s also important to note that the medication can induce side effects, such as sleepiness.
Even if you don’t have epilepsy, many people still suffer from Occipital Lobe Seizures because they want or need to light things up at night. You can purchase flashlights using LED bulbs and strobe lights (which look like small flashlights when turned on). Sometimes these flashlights are referred to as “nightlights” or “night lights” (different manufacturers use different names).
Sometimes these flashlights are made specifically for children who experience daytime seizures caused by Epilepsy. These nightlights come in a variety of shapes, textures and colors – and even have blinking lights!
Parietal Lobe Seizures
Parietal lobe seizures are more common in children but can occur at any age. These seizures can affect the ability to move, perceive temperature and pain, recognize objects, and even read.
Parietal lobe seizures begin in the parietal lobe of the brain. This area of the brain is located toward the top center, near a line running between your ears. The parietal lobe helps with perception of information from different senses and understanding language.
Parietal lobe seizures are more common in children but can occur at any age. These seizures can affect the ability to move, perceive temperature and pain, recognize objects, and even read.
Generalized Seizures
Generalized seizures are produced by abnormal electrical activity that affects the entire brain at once.
Types of Generalized Seizures
There are six types of generalized seizures:
Absence seizures: The person may appear to space out for a few seconds, which is called an absence seizure, or stare off into space. These typically last only a few seconds and don’t have any warning signs. They often happen several times a day in people with this type of seizure.
Clonic seizures: These are also called convulsive seizures and involve repeated or rhythmic, jerking movements of the arms and legs. The person may fall to the ground, stiffen or twitch. This type of seizure typically lasts 1–3 minutes.
Myoclonic seizures: Myoclonic means muscle jerking. These types of seizures cause quick jerks or twitches of the arms and legs.
Tonic-clonic seizures: Tonic-clonic means toning down (tonic) and intense (clonic). These used to be known as grand mal seizures. They start with stiffening of the limbs (the tonic phase), followed by shaking (the clonic phase).
Absence Seizures
Absence seizures, previously known as petit mal seizures, often occur in children and are characterized by staring into space or subtle body movements, such as eye blinking or lip smacking. These seizures may occur in clusters and cause a brief loss of awareness.
Absence seizures usually don’t cause any lasting injury. Most children who have absence seizures eventually outgrow them without long-term problems. Treatment might not be necessary if your child’s absence seizures don’t interfere with daily activities. However, some children require treatment to control their seizures and prevent serious harm.
Symptoms
An absence seizure causes a short period of “blanking out” or staring into space. These seizures may occur in clusters throughout the day, several times a day over many days or weeks. They’re brief — typically lasting only seconds — but can happen many times per day without warning.
Myoclonic Seizures
Myoclonic seizures are the most common type of seizures seen in adults with juvenile myoclonic epilepsy (JME). They are brief, shock-like jerks of a muscle or a group of muscles. These seizures usually only involve the arms, although the neck and head may be involved as well. They can occur singly or in clusters, and often happen soon after waking.
Myoclonic seizures can be very brief so that they appear to be sudden muscle jerks without any warning features. At other times they can be preceded by an aura or feeling of unease.
Myoclonic seizures are not always easy to recognize; they may be confused with other movement disorders such as tremor or dystonia, which also cause involuntary movements.
Generalized Convulsive Seizures
Generalized convulsive seizures are the most common type of generalized seizure, occurring in about 60% of all patients with epilepsy. The overall incidence of generalized seizures is between 30 and 40 per 100,000 person-years. Generalized convulsive seizures are identified either by the presence of tonic-clonic movements or by the presence of typical electroencephalography (EEG) changes that are associated with these types of seizures (see Clinical and EEG Classification of Epileptic Seizures).
Generalized convulsive seizures begin abruptly. The patient loses consciousness, falls to the ground, and then develops tonic muscle contraction followed by rhythmic clonic jerking. After a period that lasts usually less than 1 minute but may be as long as 3 minutes, the jerking stops and consciousness returns. Patients may remember nothing about this event, or they may recall a brief dreamlike state or a sudden fear. They may experience only confusion for a few minutes after regaining consciousness.
Symptomatic Generalized Epilepsy
Symptomatic generalized epilepsy is a group of epilepsies that are related to structural brain abnormalities or other medical conditions.
Symptomatic generalized epilepsy can be further subdivided into the following:
Idiopathic generalized epilepsies with a specific syndrome, such as childhood absence epilepsy (CAE), juvenile myoclonic epilepsy (JME), and juvenile absence epilepsy (JAE) with a specific syndrome.
Symptomatic epilepsies with generalized tonic-clonic seizures only.
Symptomatic generalized epilepsies where patients have seizures of more than one type, including generalized tonic-clonic seizures.
Progressive Myoclonic Epilepsy
Progressive myoclonic epilepsy (PME) is a rare form of epilepsy that affects less than 1% of the general population. It causes seizures that are both myoclonic (jerks or twitches) and progressive (get worse), as well as other symptoms that get worse over time.
These disorders are generally subdivided into early-onset and late-onset PME. The early-onset forms are called UnverrichtLundborg disease (ULD), Lafora body disease (LBD), sialidosis type II, neuronal ceroid lipofuscinosis (NCL), and mitochondrial cytopathies. The late-onset forms include GRN-related PME and neurodegeneration with brain iron accumulation (NBIA).
Reflex Epilepsy
Epilepsy is a chronic neurological disorder that causes periodic, unpredictable seizures. During a seizure, the brain’s normal electrical activity becomes abnormal. The brain is made up of millions of nerve cells (neurons) that communicate with each other by sending electrical and chemical signals from one to another. If a group of neurons “fires” together too often, this synchronous firing may result in a seizure.
In reflex epilepsy, seizures are caused by a certain stimulus or trigger, such as flashing lights or specific patterns. This type of epilepsy is also called sensory-induced, stimulus-induced or photosensitive epilepsy.
Neonatal Onset Epilepsy Syndromes and Seizure Disorders
Neonatal seizures are a serious problem in the newborn period. In infants, there is a wide spectrum of neonatal seizures, ranging from subtle to overt. These seizures can be subtle, involve only small areas of the brain, and be difficult to recognize.
Neonatal seizures can be generalized or focal. Early recognition of neonatal seizures is crucial for appropriate treatment and long-term prognosis.
Ohtahara Syndrome
Ohtahara syndrome, or Ohtahara’s sign, is a medical condition in which a patient has difficulty pronouncing the last letter of a word. This can happen during the final portion of speech. Some victims also have difficulty articulating the beginning of a word, which can make it difficult to articulate the entire word.
Benign Familial Neonatal Seizures
Benign Familial Neonatal Seizures (BFNS) is a condition that affects infants. BFNS is considered a type of epilepsy, which refers to a group of neurological disorders in which brain activity becomes abnormal, causing seizures or periods of unusual behavior, sensations, and sometimes loss of consciousness. Epilepsy occurs when nerve cells in the brain send out abnormal signals.
Infantile Onset Epilepsy Syndromes and Seizure Disorders
The Infantile Onset Epilepsy Syndromes and Seizure Disorders program at Boston Children’s Hospital provides expert care for children with a variety of seizure disorders. We focus on detecting these disorders early, starting therapy as quickly as possible and working with families to provide the best care possible.
Infantile Spasms
Infantile Spasms are a rare form of epilepsy that can occur in infants. While still a baby, the infant will have seizures that cause the child to bend forward or stiffen into a ball. These seizures will tend to occur in clusters and not just once.
They are usually caused by abnormal brain development, but in some cases may be caused by infection or injury. There is no known cure for Infantile Spasms, but with the proper treatment, it can be managed and controlled until the child is older.
Dravet Syndrome
Dravet syndrome (DS) is a rare, catastrophic, lifelong form of epilepsy that begins in the first year of life with frequent and/or prolonged seizures. Seizures are often triggered by hot temperatures or fever (though febrile seizures do not necessarily indicate DS). Other seizure types include myoclonic, atonic, tonic, and absences. In addition to epilepsy, people with Dravet syndrome may have delayed development of language and motor skills, hyperactivity, difficulty relating to others, irritability, impulsivity, and challenges with coordination and balance.
Neurologic Disorders
Neurologic disorders are diseases of the brain, spine and the nerves that connect them. There are more than 600 diseases of the nervous system, such as brain tumors, epilepsy, Parkinson’s disease and stroke as well as less familiar ones such as frontotemporal dementia.
Neurologic disorders can be short-lived (acute) or long lasting (chronic). Some are progressive and worsen over time, while others are stable. Some cause the symptoms to appear suddenly; others develop slowly over months or years.
Rett Syndrome
Rett syndrome is a rare genetic neurological and developmental disorder that typically becomes apparent after 6 to 18 months of age in females. It is characterized by near or complete cessation of growth, followed by a period of regression in communication and hand skills. The condition severely affects the ability to speak, walk, eat, and breathe easily.
Angelman Syndrome
Angelman syndrome (AS) is a neurogenetic disorder characterized by severe intellectual and developmental delay, lack of speech, seizures, jerky movements (especially hand-flapping), frequent laughter or smiling, and usually a happy demeanor. It is caused by the loss of function of the maternal copy of the ubiquitin protein ligase E3A gene.
Tuberous Sclerosis
Tuberous sclerosis is a rare genetic disorder that can affect any organ system, but which typically causes noncancerous tumors to grow in the brain and kidneys. The central nervous system, heart, lungs, eyes and skin may also be affected. Specific signs and symptoms depend on the organs involved.
The signs and symptoms of tuberous sclerosis can vary widely from person to person, even among members of the same family. In some cases, you may not know whether a loved one has the condition until later in life — or even until after death when an autopsy is done.
Sturge-Weber Syndrome
Sturge-Weber syndrome (SWS) is a birthmark that usually appears on the face. It is caused by abnormal blood vessels under the skin. The birthmark affects the skin and sometimes other parts of the body.
Sturge-Weber syndrome is also called encephalotrigeminal angiomatosis. It is a sporadic disorder, which means it occurs by chance rather than being inherited from a parent. It is not contagious or infectious.
Childhood Onset Epilepsy Syndromes and Seizure Disorders
The diagnosis of a childhood onset epilepsy is one of the most challenging. The diagnosis frequently requires a rigorous evaluation to determine the etiology of the condition, and therefore, the most appropriate treatment.
Febrile Seizures
Febrile seizures occur in 2% to 5% of all children between the ages of 6 months and 5 years. Most children who have a febrile seizure will not develop epilepsy.
The most important thing you can do is to stay calm. Febrile seizures are scary, but they don’t cause brain damage and usually aren’t dangerous. Most last less than 10 minutes, though some may go for as long as 15 minutes.
Landau-Kleffner Syndrome
Landau-Kleffner syndrome (LKS) is a rare childhood neurological disorder that causes the sudden or gradual loss of ability to understand and use spoken language. This disorder may be associated with an abnormal electroencephalogram (EEG), a test that measures electrical activity in the brain. Some cases of LKS also involve behavioral problems, including hyperactivity, aggressiveness, and outbursts of rage.
Lennox-Gastaut Syndrome
Lennox-Gastaut syndrome (LGS) is a type of epilepsy that begins in childhood. It’s characterized by multiple types of seizures, slow spike-and-wave patterns on a type of brain wave test called an electroencephalogram (EEG), and delayed development.
Rasmussen Syndrome
Rasmussen syndrome (also known as Rasmussen encephalitis, Rasmussen’s encephalitis, chronic focal encephalitis, or chronic focal and segmental encephalitis) is a rare, acquired neurological disorder that causes seizures and neurologic deficits.
Rasmussen syndrome usually starts before the age of 10 years with seizures that are characterized by motor weakness in one side of the body or tonic (“staring”) seizures. In many cases, these symptoms become progressively worse over time.
Gelastic Epilepsy
Gelastic seizure, also known as laughing epilepsy, is a rare form of epilepsy in which a person has seizures that involve laughing or crying. These seizures are usually brief and occur several times a day. Between seizures, people with gelastic epilepsy are typically normal.
The symptoms of gelastic epilepsy vary from person to person. A seizure typically lasts for less than a minute and may be followed by confusion or sleepiness. Seizures are often triggered by laughter or other external stimuli, such as light or sound.
Benign Rolandic Epilepsy
Benign Rolandic Epilepsy is one of the most common forms of epilepsy. It is characterized by seizures of the face and tongue, usually at night. Seizures are usually not associated with loss of consciousness or sudden falls to the ground, but may present as strange sensations in the mouth area, such as numbness or tingling. The seizures tend to get worse with age and are often outgrown by adolescence.
Benign Occipital Epilepsy
A Benign Occipital Epilepsy (BOE) is a form of epilepsy that is characterized by visual disturbances. These disturbances may consist of flashing lights, geometric patterns or other hallucinatory phenomena. The symptoms of this condition are not life threatening, unlike other epilepsy syndromes. People with BOE may have seizures before falling asleep, during sleep and waking up. The seizures may occur in the absence of any abnormal neurological findings.
Childhood Absence Epilepsy
Childhood absence epilepsy is a form of epilepsy that causes the child to have brief seizures and become “absent” during the seizure. Childhood absence epilepsy can be difficult to recognize. The child will seem normal, but he or she is unaware of what is happening around him or her during the seizure.
Symptoms
The most common symptom of childhood absence epilepsy is staring into space and being unresponsive for short bursts of time. This is often followed by confusion, which lasts anywhere from a few seconds to a few minutes. Other symptoms include blinking, eye movements and small facial movements.
Juvenile Myoclonic Epilepsy
Juvenile myoclonic epilepsy (JME) is a syndrome characterized by myoclonic jerks, generalized tonic-clonic seizures and sometimes absence seizures. JME is the most common form of idiopathic generalized epilepsy. It usually starts in adolescence, and often runs in families.