Epilepsy Syndromes
Epilepsy is a complex neurological condition, and it manifests in various ways. Let’s explore some of the distinct epilepsy syndromes—each with its unique characteristics and age of onset:
Autosomal Dominant Nocturnal Frontal Lobe Epilepsy (ADNFLE):
Age of Onset: Typically during adulthood.
Key Features: Sleep-related seizures originating from the frontal lobes.
Autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) is a rare inherited form of epilepsy characterized by seizures that predominantly occur during sleep, often in clusters. These seizures can range from mild episodes that briefly awaken the person to more severe ones involving sudden, repetitive movements like flinging arms or bicycling legs, which can be mistaken for sleepwalking or night terrors. Seizures may be preceded by an aura, with symptoms such as tingling, fear, dizziness, or breathlessness. While the exact triggers are unclear, stress and fatigue may play a role. Seizures typically start in childhood and often become less severe with age, with most cases responding well to medication. People with ADNFLE generally have normal intellectual function, though some may experience psychiatric or behavioral issues, the connection of which to the epilepsy remains uncertain. SOURCE
Rolandic Epilepsy:
Age of Onset: Childhood (between 2 and 17 years).
Characteristics: Focal seizures, often involving the face and mouth area.
Benign Rolandic Epilepsy (BRE), also known as benign epilepsy with centrotemporal spikes (BECTS), is a common childhood epilepsy syndrome, typically starting between ages 6 and 8. Affecting boys more often than girls, it accounts for 15% of childhood epilepsy cases. Seizures are usually brief, lasting no more than two minutes, and occur infrequently, often at night. They are characterized by twitching, numbness, or tingling of the face or tongue, which can interfere with speech and cause drooling. While most children outgrow the condition during adolescence, some may experience daytime seizures, sleep disturbances, or challenges with reading and attention. In such cases, medication like levetiracetam, valproic acid, or oxcarbazepine may be recommended. SOURCE
Childhood Absence Epilepsy (CAE):
Age of Onset: Childhood.
Distinctive Signs: Brief staring spells (absence seizures) with minimal motor involvement.
Childhood Absence Epilepsy (CAE) is a common type of absence epilepsy in children, marked by frequent daily seizures that usually begin between ages 4 and 10. These seizures involve brief staring spells, where the child is unaware and unresponsive, sometimes accompanied by subtle eye rolling. CAE is often confused with Juvenile Absence Epilepsy (JAE), but CAE seizures occur more frequently, sometimes multiple times a day. While most children with CAE outgrow the condition by their mid-teens, a small percentage may also experience tonic-clonic seizures. Diagnosis typically involves an EEG and possibly an MRI to rule out other conditions. Treatment often includes anti-seizure medications, and in some cases, a ketogenic diet if medication is ineffective. Though children with CAE usually have normal intelligence, some may struggle with attention issues or anxiety. With proper treatment, most children with CAE can expect their seizures to subside by adolescence. SOURCE
Dravet Syndrome:
Age of Onset: Infancy (usually within the first year of life).
Notable Features: Severe, drug-resistant seizures, often triggered by fever.
Dravet Syndrome, formerly known as Severe Myoclonic Epilepsy of Infancy (SMEI), is a rare and severe developmental and epileptic encephalopathy (DEE) that begins in infancy and has lasting impacts throughout life. Affecting approximately 1 in 15,700 individuals, most cases are linked to mutations in the SCN1A gene. Dravet syndrome typically starts between 2 to 15 months of age, often triggered by fever or warm temperatures, and is characterized by frequent, prolonged seizures that are difficult to control with existing medications. Over time, various seizure types emerge, accompanied by significant developmental delays, behavioral issues, movement and balance challenges, speech delays, and other comorbidities, including dysautonomia and chronic infections. The syndrome carries a high mortality rate, with 15-20% of patients succumbing to SUDEP (Sudden Unexpected Death in Epilepsy), prolonged seizures, or seizure-related accidents. Current treatments are limited, but ongoing research into disease-modifying therapies provides hope for improving the quality of life for those affected. SOURCE
Lennox–Gastaut Syndrome (LGS):
Age of Onset: Usually during childhood.
Characteristics: Multiple seizure types (tonic, atonic, atypical absence), cognitive impairment, and slow spike-and-wave patterns on EEG.
Lennox-Gastaut Syndrome (LGS) is a rare and severe epilepsy syndrome that typically develops in early childhood, leading to lifelong disability for many. Affecting about 50,000 people in the U.S. and 1 million worldwide, LGS is characterized by multiple seizure types, abnormal brain waves on EEGs, and developmental delays or intellectual disabilities. Seizures usually begin in the first three years of life, and while the condition’s severity varies, it is always considered serious, often requiring lifelong care. Despite treatment, more than 85% of those with LGS will continue to have seizures into adulthood, and over 90% will experience significant intellectual disabilities. The syndrome carries a heightened risk of injuries, aspiration pneumonia, and early death, including from SUDEP (Sudden Unexpected Death in Epilepsy). While there is no cure for LGS, various seizure management options are available, including anti-seizure medications, specialized diets, and surgical interventions. The LGS Foundation provides valuable resources and support for families affected by this challenging condition, offering hope and community in the face of adversity. SOURCE
Ohtahara Syndrome:
Age of Onset: Neonatal period (within the first few weeks of life).
Hallmarks: Severe seizures, often associated with brain malformations.
Ohtahara Syndrome is a rare and severe form of epilepsy that typically begins within the first three months of life, often manifesting within the first 10 days, and is characterized by frequent seizures and significant developmental delays. Both boys and girls are equally affected, with the most common seizures being tonic, involving muscle stiffening, upward eye gaze, dilated pupils, and altered breathing, though focal and myoclonic seizures may also occur. The condition can result from brain abnormalities, metabolic disorders, or gene mutations, though some cases have no known cause. Key symptoms include early-onset seizures, developmental and muscle movement delays, intellectual disability, and a burst suppression pattern on EEGs. There is currently no cure for Ohtahara syndrome, but treatment options include corticosteroids, a ketogenic diet, various therapies, and, in some cases, epilepsy surgery if a focal brain lesion is present. Clinical trials play a critical role in advancing understanding and treatment, involving volunteers to ensure that research findings are widely applicable and that new treatments are safe and effective for everyone. SOURCE
Temporal Lobe Epilepsy (TLE):
Age of Onset: Typically in adulthood.
Features: Focal seizures originating in the temporal lobes, often associated with altered consciousness or déjà vu experiences.
Temporal Lobe Epilepsy (TLE) begins in the temporal lobe of the brain, where about 80% of seizures originate near the hippocampus. This type of epilepsy, affecting around 60% of people with focal epilepsy, can be controlled by medications in about two-thirds of cases, and those with seizures starting near the hippocampus often benefit from surgery. The temporal lobes are crucial for functions like memory, sound processing, and emotional responses. TLE can start at any age, typically between 10 and 20 years, and risk factors include febrile seizures, brain injuries, and structural brain abnormalities. Symptoms vary depending on the seizure’s origin, ranging from auras—sensations like déjà vu or anxiety—to more severe seizures involving loss of awareness and physical convulsions. The causes of TLE include unknown factors, brain injuries, infections, genetic factors, and abnormalities present from birth. Diagnosis involves a range of tests, including MRI, EEG, and PET scans. Treatments include medications, ketogenic diets, surgery, laser ablation, and electrical brain stimulators, depending on the individual case. Preventive measures focus on reducing risks associated with brain injuries and other health events that might trigger seizures. The prognosis for TLE varies, with many patients achieving seizure control through medication or surgery, though ongoing medical care is essential for managing the condition and maintaining quality of life. SOURCE
Reflex Epilepsies:
Age of Onset: Varies.
Unique Aspect: Seizures triggered by specific stimuli (e.g., flashing lights, reading, or hot water immersion
Reflex epilepsy is a condition where seizures are habitually triggered by specific external stimuli, such as visual, sensory, auditory, somatosensory, olfactory, or proprioceptive inputs, or, less commonly, by internal mental processes. In individuals with pure reflex epilepsy, seizures occur almost exclusively in response to these triggers, though reflex seizures can also coexist with spontaneous ones. Reflex seizures may manifest as partial or generalized, with visual stimuli being the most common trigger. Reflex epilepsy is relatively rare, accounting for only 5% of all epilepsy cases, with most being genetic in origin. Photosensitive epilepsy, triggered by intermittent light stimulation, is the most common type. The diagnosis of reflex epilepsy is confirmed when seizures consistently occur in response to specific stimuli, although many individuals also experience spontaneous seizures, with interictal epileptic discharges (IEDs) often being provoked by these triggers. SOURCE
Angelman Syndrome:
Age of Onset: Childhood.
Characteristics: Developmental delays, intellectual disability, severe speech impairment, ataxia, seizures, microcephaly, frequent laughter.
Angelman syndrome is a complex genetic disorder affecting the nervous system, characterized by delayed development, intellectual disability, severe speech impairment, and movement and balance issues (ataxia). Common features include recurrent seizures (epilepsy) and microcephaly (small head size), with developmental delays noticeable by 6 to 12 months of age. Affected children often exhibit a cheerful demeanor, frequent smiling, laughter, hand-flapping, hyperactivity, and a short attention span, along with sleep disturbances. As individuals with Angelman syndrome age, they become less excitable and their sleep issues may improve, but they continue to experience intellectual disability, severe speech impairment, and seizures throughout their lives. Adults with the syndrome may have distinctive “coarse” facial features, light skin and hair, and scoliosis (curvature of the spine). Despite these challenges, life expectancy is generally near normal. SOURCE
Rasmussen’s Encephalitis:
Age of Onset: 6-10 years
Characteristics: Progressive neurological disorder characterized by focal seizures, hemiparesis, and cognitive decline. Often resistant to treatment. MRI shows progressive atrophy of one hemisphere.
Rasmussen’s Encephalitis (RE), also known as Rasmussen syndrome, is a rare neurological condition characterized by chronic inflammation of one hemisphere of the brain, leading to severe and progressive brain damage. This condition typically presents with frequent seizures, including generalized tonic-clonic seizures, focal aware seizures, and focal impaired awareness seizures. In children, symptoms often start with seizures and mild weakness in an arm or leg, progressing to frequent, intractable seizures, cognitive decline, loss of motor skills on one side of the body, and partial loss of sight. The cause of RE is unclear but may involve autoimmune responses or viral infections. Diagnosis involves MRI and EEG to detect brain atrophy and abnormal electrical activity. While there is no cure, treatment focuses on managing symptoms through antiseizure medications, immunotherapy, and potentially hemispherectomy (surgical removal of one brain hemisphere). Prognosis varies, with some individuals experiencing stabilization after surgery, though many continue to face challenges like paralysis and cognitive impairment. SOURCE
Landau-Kleffner Syndrome:
Age of Onset: 3-7 years
Characteristics: Acquired aphasia (loss of language skills), with seizures that are often focal or generalized. EEG shows continuous spike-and-wave activity during sleep.
Landau-Kleffner Syndrome (LKS) is a rare neurological disorder that typically affects children between the ages of 5 and 7, characterized by a sudden or gradual loss of the ability to use or understand spoken language. The condition often begins with auditory agnosia, where the child has difficulty understanding spoken words, which may lead to the suspicion of hearing problems or developmental delays. As the syndrome progresses, it can result in the complete loss of speech and may be associated with seizure disorders. Children with LKS often develop alternative communication methods, such as gestures or signs, and hearing and intelligence are usually normal. Diagnosis is commonly made using an electroencephalogram (EEG) to assess brain electrical activity. Treatment typically involves managing seizures with medication, addressing language impairments through speech therapy, and potentially using sign-language instruction. SOURCE
Juvenile Myoclonic Epilepsy (JME):
Age of Onset: 12-18 years
Characteristics: Myoclonic jerks, particularly in the morning, often followed by generalized tonic-clonic seizures. Photosensitivity is common. EEG shows 4-6 Hz polyspike-and-wave discharges.
Juvenile Myoclonic Epilepsy (JME) is a common form of epilepsy that typically begins during adolescence. It is characterized by myoclonic seizures, which involve sudden, brief jerks or twitches of the arms, shoulders, or occasionally the legs, often occurring upon waking. Most individuals with JME also experience generalized tonic-clonic seizures, which involve more widespread muscle contractions and convulsions. A minority, around 20%, may also have absence seizures, marked by brief periods of unresponsiveness. JME is often linked to genetic factors, and while the exact cause is unknown, some individuals may have a history of fever-related seizures or childhood absence epilepsy. Seizure triggers for JME include irregular sleep patterns, alcohol, caffeine, stress, and flickering lights. Diagnosis is confirmed through an electroencephalogram (EEG), which reveals characteristic brain wave patterns. Although JME may be a lifelong condition, effective management with seizure medications can significantly reduce or eliminate seizures for most individuals. SOURCE
Panayiotopoulos Syndrome (PS) (also known as early onset childhood occipital epilepsy):
Age of Onset: 3-6 years
Characteristics: Children with PS have normal physical and cognitive development. Seizures commonly come from the occipital lobes, which as located in the back of the brain. Seizure start as focal seizures that evolve to a generalized seizures. During the seizure, the child may look pale, complain of feeling sick and may vomit. They may faint and pupils dilate. During the seizure, some children may be unable to see, see flashing colorful or bright lights or have blurred vision.
Panayiotopoulos Syndrome is a recognized idiopathic childhood seizure disorder, characterized by prolonged seizures with predominantly autonomic symptoms and an EEG showing shifting or multiple foci, often with occipital predominance. It primarily affects children in early to mid-childhood and presents with autonomic epileptic seizures, which can include symptoms such as emesis, pallor, mydriasis, and alterations in cardiorespiratory and thermoregulatory functions. Seizures may also include ictal syncope or convulsions and can last longer than 30 minutes, leading to autonomic status epilepticus. The condition is notably benign, with a low risk of residual neurologic deficits and no higher risk of adult epilepsy compared to the general population. Accurate diagnosis is crucial as the syndrome’s features can be mistaken for other conditions like encephalitis or cyclic vomiting syndrome. Management involves educating about the syndrome, with prophylactic antiepileptic medication often unnecessary, though acute autonomic status epilepticus requires careful evaluation and treatment to avoid complications. SOURCE