Using ACTH for Infantile Spasms: What to Expect

Infantile spasms are a serious form of epilepsy that emerges in the first year of life. This condition requires prompt medical attention to manage the seizures and support developmental outcomes. One of the primary treatments used is Adrenocorticotropic Hormone (ACTH), a therapy aimed at controlling the spasms and improving abnormal brain wave patterns. Understanding this treatment is important for caregivers of infants diagnosed with this condition.

Understanding Infantile Spasms

Infantile spasms (IS) are a specific type of seizure that begin when a baby is between 3 and 8 months old. The spasms are sudden, brief stiffening movements of the body. These can look different from one infant to another; some may bend forward with their arms flung out and knees pulled up, while others might arch their back with their limbs extended. In some cases, the movements are more subtle, involving only head nods or eye rolling.

These seizures often happen in clusters, with each spasm lasting only a second or two, occurring one after another every five to ten seconds. Diagnosing infantile spasms requires an electroencephalogram (EEG), which records the brain’s electrical activity. In many infants with this condition, the EEG shows a chaotic and disorganized pattern between spasms called hypsarrhythmia.

Because the spasms and underlying brain activity can interfere with normal development, sometimes causing a loss of previously acquired skills like babbling or rolling over, medical providers move quickly to identify the condition and begin treatment.

ACTH Therapy for Infantile Spasms

Adrenocorticotropic Hormone (ACTH) is a hormonal therapy recognized as a first-line treatment for infantile spasms. This medication is a peptide hormone that is naturally produced by the pituitary gland. The therapy is administered through intramuscular injections, which parents are taught to give at home.

A medical team will determine the most appropriate treatment plan for each infant, with discussions often revolving around high-dose versus low-dose regimens. While some studies suggest high-dose ACTH is more effective, there is no definitive consensus. A typical course of treatment involves daily injections for several weeks, often around six, followed by a gradual tapering of the dose.

The exact way ACTH works to stop infantile spasms is not completely understood. One proposed mechanism is that it stimulates the adrenal glands to release corticosteroid hormones, which can have anti-inflammatory and seizure-suppressing effects on the brain. Another theory suggests ACTH may act directly on receptors in the brain to reduce neuronal excitability and decrease the production of corticotropin-releasing hormone (CRH), a peptide that can promote seizures.

Clinical Response to ACTH and Outlook

The primary goal of ACTH therapy is to achieve a complete stop of the clinical spasms and a resolution of the hypsarrhythmia pattern on the EEG. A positive response is often seen within the first two weeks of starting treatment. Medical teams monitor for this response through parental reports of seizure activity and follow-up EEG tests.

When an infant responds well to ACTH, the outlook can be more favorable, though it varies widely depending on the underlying cause of the spasms. For some children, especially those without a known underlying cause (formerly termed cryptogenic), rapid and successful treatment can lead to better long-term neurodevelopmental outcomes.

Despite a good initial response, relapses can occur, with rates reported to be between 30% and 72%. In cases of relapse, different treatment strategies may be considered, including another course of ACTH. Continued medical follow-up is a standard part of their care.

Managing ACTH-Related Side Effects and Monitoring

ACTH therapy involves a range of potential side effects. Common, and often temporary, side effects include significant irritability, increased appetite and weight gain, and facial swelling known as “moon face.” These effects resolve after the treatment course is completed.

More significant medical side effects require close monitoring. High blood pressure (hypertension) is a frequent concern, requiring regular checks. The treatment can also lead to elevated blood sugar levels. Because ACTH suppresses the immune system, infants are more susceptible to infections, and caregivers are advised to be vigilant for any signs of illness and limit exposure to contagious diseases.

A monitoring plan includes regular visits with the medical team or a home-visiting nurse to check blood pressure and other vital signs. Medications may be prescribed to control high blood pressure, and prophylactic medicines like famotidine may be given to protect the stomach.