Infantile spasms are a rare, severe form of epilepsy primarily affecting infants aged 4 to 8 months, though they can occur up to 2 years. They are a medical emergency due to their potential to disrupt brain development. Untreated, they can lead to significant neurodevelopmental consequences, including intellectual disability and developmental delays. Early recognition and prompt treatment are crucial for improving a child’s developmental outcome and quality of life.
Recognizing the Signs
Infantile spasms are sudden, brief movements, often resembling a startle reflex. They typically involve a sudden stiffening of the body, with the head nodding forward, arms flinging out, and knees pulling up (a “jackknife” seizure). Alternatively, the head may be thrown back with the body and legs stiffening. Each spasm lasts one to two seconds, but they commonly occur in clusters, with multiple spasms happening every 5 to 15 seconds for several minutes.
Spasms are most common when a baby wakes from sleep, but can occur at any time. Intensity varies from dramatic jerks to subtle movements like brief head nods, eye rolling, or belly tensing. Due to their subtlety, they are often mistaken for normal infant behaviors like colic, reflux, or a startle reflex. If suspicious movements are observed, especially in clusters, video record them to show a healthcare provider for assessment.
Understanding the Underlying Causes
Infantile spasms are a symptom of an underlying brain abnormality or condition, not a standalone disease. Identifying the specific cause is important as it guides treatment and prognosis. Causes are broadly categorized as structural, metabolic, genetic, or unknown (cryptogenic).
Structural causes include physical brain abnormalities present from birth or resulting from injury. Examples are malformations (e.g., cortical dysplasia), stroke, brain infections (e.g., meningitis), or oxygen deprivation. Metabolic causes are disorders affecting the body’s chemical processes that disrupt brain function.
Genetic factors are significant, with mutations in genes like TSC1 or TSC2 (associated with Tuberous Sclerosis Complex) being common contributors. Over 100 genes link to infantile spasms, and genetic testing identifies a cause in up to 40% of cases. Despite advancements, the cause remains unknown in a notable percentage, classified as cryptogenic.
Diagnosis and Treatment Approaches
Diagnosis begins with clinical evaluation of observed movements, often supplemented by caregiver videos. It is confirmed by an electroencephalogram (EEG), which measures brain electrical activity. A characteristic EEG pattern, “hypsarrhythmia,” is associated with infantile spasms, marked by disorganized, high-voltage slow waves and spikes. Additional tests include brain MRI for structural abnormalities or injuries, and genetic/metabolic testing for underlying mutations or disorders.
Treatment goals are to stop spasms and normalize the EEG pattern, ideally resolving hypsarrhythmia. Early, effective treatment improves long-term outcomes.
First-line medications include adrenocorticotropic hormone (ACTH) and vigabatrin. ACTH is a hormonal therapy effective in stopping spasms and normalizing EEG readings. Vigabatrin, an anti-seizure medication, is particularly effective for spasms caused by Tuberous Sclerosis Complex. Other treatments like corticosteroids, topiramate, or the ketogenic diet may be considered if first-line therapies are ineffective or as adjunctive treatments, depending on the underlying cause and individual response.
Ongoing Care and Support
Following diagnosis and initial treatment, ongoing care involves continuous follow-up with neurologists and developmental specialists. This multidisciplinary approach monitors the child’s neurological health and developmental progress. Regular assessments detect potential delays or skill regression, even if spasms are controlled.
Early intervention therapies are fundamental to ongoing care, regardless of cause or seizure control effectiveness. These include physical therapy for motor skills, occupational therapy for fine motor skills and daily living activities, and speech therapy for communication. Interventions are tailored to the child’s needs to help achieve developmental milestones. Families benefit from support groups and resources providing guidance, emotional support, and practical advice.