Infantile spasms are a rare, serious form of epilepsy affecting infants, characterized by subtle, repetitive movements. These spasms often appear in clusters and require prompt diagnosis and treatment. Early intervention is important to minimize their impact on a child’s development and prevent severe developmental consequences.
Identifying Infantile Spasms
Infantile spasms typically manifest as sudden, brief stiffening movements of the body. Infants might bend forward, with arms flinging out and knees pulling up, or arch their backs while extending arms and legs. These movements are often subtle, sometimes involving a head nod, eye rolling, or tensing of the abdomen. Each spasm lasts one to two seconds but usually occurs in a rapid series or “cluster,” repeating every five to ten seconds.
Onset is typically between 3 and 12 months, with a peak incidence around 6 months of age. Spasms most commonly happen just after waking from sleep and rarely occur during sleep. Parents might initially mistake these movements for benign actions like the startle reflex, colic, or other normal baby behaviors, making early recognition challenging. Recording a video of suspected spasms can help medical professionals review and confirm a diagnosis.
Exploring Causes
Infantile spasms are often a symptom of an underlying brain abnormality or injury, occurring either before or after birth. A wide range of conditions can lead to infantile spasms, including structural brain issues like malformations (e.g., cortical dysplasia), stroke, or injury from lack of oxygen to the brain. Genetic factors also play a role, with mutations in specific genes identified as causes.
Metabolic disorders, which affect the body’s chemical processes, and infections can also trigger these spasms. Examples include phenylketonuria and meningitis. In approximately one-third of cases, a specific cause cannot be identified; these are referred to as cryptogenic infantile spasms. Determining the underlying cause is important as it guides treatment and provides insight into the child’s potential developmental trajectory.
Treatment Approaches
Effective treatment aims to stop seizures and normalize abnormal brainwave patterns. Primary medical treatments are hormonal therapy and vigabatrin. Adrenocorticotropic hormone (ACTH) and corticosteroids, such as prednisolone, are hormonal therapies often used as first-line treatments. ACTH is thought to reduce neuronal excitability by promoting adrenal steroid release and potentially by directly affecting certain brain receptors.
Vigabatrin is an anti-seizure medication that increases gamma-aminobutyric acid (GABA) levels in the brain, helping to control seizure activity. It is often a first-line choice, particularly for infants with tuberous sclerosis complex. The choice of treatment often depends on the underlying cause.
If initial treatments are not effective, other options may be considered. The ketogenic diet, a high-fat, low-carbohydrate diet, can be used to manage seizures in some cases. Epilepsy surgery may be an option for children with a specific, localized brain abnormality that can be removed. Surgery aims to remove the affected brain area to reduce seizure activity, leading to improved outcomes for appropriate candidates.
Outlook for Children
The concept of “cure” for infantile spasms typically means the cessation of spasms and the resolution of the characteristic chaotic brainwave pattern known as hypsarrhythmia on an electroencephalogram (EEG). While spasms can often be stopped with treatment, the underlying brain condition may still affect a child’s development. The long-term developmental outcome varies significantly, depending on the specific underlying cause and how promptly the spasms were controlled.
Early recognition and prompt, successful treatment are associated with better long-term outcomes. However, even after spasms cease, children may still experience developmental delays, intellectual disabilities, or other forms of epilepsy later in life, such as Lennox-Gastaut syndrome. For instance, a favorable cognitive outcome is observed in approximately one-quarter of patients, and complete seizure freedom in about one-third. Ongoing developmental support and follow-up care are important to address challenges and support a child’s progress.