Rare Epileptic Syndromes
A Review: Rare Epileptic Syndromes
Shivani Narasimhan
A rare epilepsy refers to a type of epilepsy that affects a small population but can have significant impacts on the individual and their family. These conditions often involve seizures that are challenging to control, with the term "refractory epilepsy" frequently applied. Managing these seizures may require a combination of multiple medications, and in some cases, alternative treatments like dietary therapies, devices, or even surgery might be considered. The exact cause of many rare epilepsies remains unclear. However, growing research points toward genetic factors that influence brain development, metabolic disorders, or conditions affecting brain function. Structural abnormalities in the brain or issues with its appearance could also contribute to these forms of epilepsy. In some cases, a combination of factors may be responsible for triggering the disorder.
The purpose of this article is to provide insight into the profound effects of "Developmental and Epileptic Encephalopathies." Developmental and epileptic encephalopathies (DEEs) are a diverse group of rare and ultra-rare epilepsy syndromes. They are characterized by seizures, behavioral disturbances, or EEG abnormalities that can lead to a direct decline in cognition and behavior. These disorders are often progressive, highly resistant to treatment, and involve two key features: impaired development (developmental encephalopathies) and regression of previously achieved developmental milestones (epileptic encephalopathies). Some of the key examples of DEE’s are as follows:
Type
Description
Dravet Syndrome
Dravet syndrome is a rare, genetic, DEE that begins in a baby’s first year, often triggered by a high fever and marked by prolonged seizures. Children with this condition experience multiple seizure types, developmental delays, and issues with speech, balance, and walking. Previously, it was known as severe myoclonic epilepsy of infancy.
Lennox-Gastaut Syndrome
Lennox-Gastaut syndrome (LGS) is a severe epileptic encephalopathy characterized by multiple types of drug-resistant seizures, cognitive impairment, and a distinctive electroencephalogram (EEG) pattern featuring slow spike-wave discharges (1.5 to 2.5 Hz) and paroxysmal fast activity during sleep. It typically manifests in early childhood, often between the ages of 3 and 5, and is associated with various underlying etiologies, including structural brain abnormalities, genetic mutations, and metabolic disorders. LGS is highly refractory to treatment and is associated with significant developmental delays and behavioral disturbances.
West Syndrome (Infantile Spasms)
West syndrome is a rare, severe form of early childhood epilepsy characterized by a triad of symptoms: infantile spasms, a specific electroencephalographic pattern called hypsarrhythmia, and developmental regression. It typically occurs in the first year of life, usually between 4 to 8 months of age. The spasms are brief, repetitive seizures that often involve sudden flexion or extension of the limbs and trunk. West syndrome is often associated with underlying brain abnormalities, genetic mutations, or metabolic disorders and can lead to significant developmental delays and cognitive impairment.
Doose Syndrome (Myoclonic-Astatic Epilepsy)
Doose syndrome, also known as Myoclonic-Astatic Epilepsy (MAE), is a rare childhood epilepsy syndrome that typically begins between the ages of 2 and 5 years. It is characterized by myoclonic seizures (brief, shock-like muscle jerks) and atonic seizures (sudden loss of muscle tone causing falls), often leading to frequent injuries. Children with Doose syndrome may experience multiple seizure types and develop drug-resistant epilepsy over time.
References
https://www.ucb.com/disease-areas/epilepsy-and-rare-syndromes
https://www.epilepsy.com/what-is-epilepsy/syndromes/dravet-syndrome
https://nyulangone.org/conditions/epilepsy-seizure-disorders-in-children/types.
