Infantile spasms are a type of epilepsy, and they were first described in 1841. They usually begin in the first year of life, mostly between 3 months and 12 months of age. Infantile spasms are sometimes referred to as forehand salutation seizures or West’s syndrome. Infantile spasms are characterized by three features: epileptic spastic seizures, disturbances in peak EEG rhythms, and impaired motor-psychological development. Etiology Infantile spasms are symptomatic in approximately 80% of cases, meaning that there is a definite intracranial lesion causing the condition. More than 200 disorders are associated with infantile spasms, including: brain malformations, tuberous sclerosis, brain injury due to various causes, including brain infections before or during the first months of life (e.g., meningitis cytomegalovirus and toxoplasmosis), hypoxia at birth, previous stroke or blood clot, or trauma to the brain, metabolic conditions, brain tumors (rare), and genetic abnormalities (e.g., Down syndrome). With improvements in neuroimaging techniques (MRI and computer scans), the percentage of infantile spasms classified as symptomatic has tended to increase in recent years. The remaining 20% of infantile spasms are cryptogenic. These children may have developmental delays prior to the appearance of spasticity, but there are no known factors contributing to the seizures and imaging observations do not show any problems. Genetic information on infantile spasms is scarce. Numerous studies have shown that 7% to 17% of children with infantile spasms have a family history of epilepsy or febrile convulsions. A small number of families (approximately 3% to 6% of cases) have a history of infantile spasms, and some of the potential causes of infantile spasms have a genetic basis. Pathogenesis The exact pathogenesis is unclear. It is now believed that infantile spasms are the result of cortical injury and subcortical brainstem function interacting with each other in the immature brain. Clinical features of infantile spasms Usually infantile spasms occur in the first year of life, usually between 3 and 8 months of age. The incidence is about 2-5% of live births. Some studies report a higher rate of infantile spasms in male infants than in female infants. The typical pattern of infantile spasms includes a slight bobbing of the head, which becomes more rapid over time. Eventually, the child begins to have flexion and extension, or mixed spasms. Flexor spasms are the most common. The child’s neck, arms, and legs are flexed toward his chest. The child often moves in a “folding knife” motion at the waist. Extensor spasms are the second most common. The child extends the neck, arms, and legs outward. Mixed spasms, in which the child’s arms and body contract and his legs extend outward, are also common. The spasms are usually symmetrical, although in some cases, the movement is stronger on one side. The intensity varies from child to child and from spasm to spasm. Some children have very subtle spasms, which may be as simple as a slight turning of the eyes to one side or a shrug of the shoulders. In most cases, the spasms are clustered. They repeat every 5 to 30 seconds, sometimes in groups of 10 to 40, and cluster spasms usually last two to three minutes, but can also be several minutes. As the cluster spasms progress, the intensity of the spasms decreases. A child may have several sets of seizures per day. Seizures rarely occur when the child is asleep and often occur when he first wakes up. He may be calm before and during a seizure, or he may cry or even laugh during the intervals between spasms. After a set of spasms, he may be exhausted or more alert. Seizures are usually not caused by any obvious stimulus. In some cases, the child may have other types of seizures (partial or generalized) before and during the spasms. After the development of infantile spasms, some children may also lose some of the skills they have developed. This means they lose the ability to sit, control their head, reach for things, smile, or chase objects with their eyes. They are less interested in people and things around them than they were before the onset of spasticity. Since most children with infantile spasms have pre-existing neurological or developmental problems, this deterioration may be difficult to determine. How infantile spasms are diagnosed Doctors usually decide if an infant has spasticity by looking at the type of seizures the child has and the pattern of the EEG between seizures. Many children with infantile spasms are characterized by disturbances in the peak rhythm of the EEG between seizures. The EEG shows random, high-voltage slow waves and almost continuous spikes. Other patterns may occur. A relationship between the EEG pattern and the underlying cause of the spasms has not yet been identified. Treatment of Infantile Spasms There are two medications that we know are the best for stopping infantile spasms. One is called aminocaproic acid tablets and the other is adrenocorticotropic hormone (ACTH). In some cases, doctors may also use other medications to control seizures. Tranexamic acid tablets are taken by mouth. It has been shown to be quite effective in controlling infantile spasms, especially in children with tuberous sclerosis. Adrenocorticotropic hormone (ACTH) is a steroidal drug given by intramuscular injection. ACTH controls infantile spasms in many cases, but it may have some side effects. Many doctors will first start treatment with aminoglutethimide tablets and switch to adrenocorticotropic hormone if the aminoglutethimide tablets do not stop the spasticity. Different studies have shown varying success rates of drug therapy. Children usually show a response to medication two weeks after the start of treatment. If the seizures are caused by a localized brain abnormality, such as a tumor or cyst, your child’s doctor may decide to perform surgery to eliminate the abnormal condition. Although there are not many studies showing how many children have infantile spasms that disappear after surgery, these cases do occur. What is the outlook for children with infantile spasms? The overall prognosis is poor, with more than half of the children evolving into other seizure types and epilepsy syndromes, with Lennox-Gastaut syndrome and complex partial seizures being the most common and usually refractory. About 50% of patients have motor impairment and 70% have intellectual disability, often with autism, ADHD and other psychiatric behavioral problems. The mortality rate for infantile spasms has been reduced to less than 5% in developed countries. As with many epilepsy syndromes, the outlook for children with infantile spasms depends on many underlying factors. The outlook may be good, or it may be poor. Many researchers believe that early treatment of children with infantile spasms improves the outlook for healing. Infantile spasms often disappear by the time a child is 3 or 4 years old. However, many children with infantile spasms continue to have neurological problems. Some may develop autism, and about half develop other forms of epilepsy later in life. In follow-up studies, an average of 17% of children with infantile spasms developed childhood-onset epileptic encephalopathy with diffuse slow spikes and slow waves (petit mal variant). Medications or surgery are only part of the treatment for epilepsy. Seizure control is the first, but not the only, step in treatment. Even when seizures are well controlled, children with epilepsy may still experience difficulties with self-esteem, learning, behavior, or social adjustment.