Infantile Spasms: Diagnosis and Treatment
Infantile spasms syndrome is a rare childhood epilepsy disorder that affects approximately 2–3 per 10,000 live births.1 The onset of infantile spasms (IS) typically occurs in children less than 12 months old, with a peak incidence between 3 and 7 months of age.2,3 This condition is characterized by clusters of myoclonic-tonic seizures that typically last less than 5 seconds, and involve flexor, extensor, or mixed flexor-extensor spasms.3 It is important to note that IS and West syndrome are often used synonymously, however patients with West syndrome also always exhibit hypsarrhythmia on electroencephalogram (EEG) and a delay in development in addition to spasms.1,3 There are two categories of IS, which are described in Table 1.
Since some evidence suggests that earlier treatment is associated with better outcomes, providers are encouraged to investigate the possibility of IS in a patient immediately.1 A detailed history and physical examination and EEG are key in diagnosing IS. Although providers often depend on caregiver reports of clinical events to determine the possibility of IS, a history and physical examination is the first step in diagnosing IS. The physical examination should concentrate on neurocutaneous stigmata of disease, which aids in identifying patients with tuberous sclerosis and allows for initiation of the appropriate treatment for this condition. History of the disease should determine the frequency of events, type of events, alterations in development, family history, and a detailed description of the pregnancy and birth.
EEG should also be performed immediately in patients that are suspected to have IS.1 A 24-hour video EEG is preferred, and EEG evaluation should include non-REM sleep if possible. Although not required for diagnosis, magnetic resonance imaging (MRI) can be used to determine the etiology of IS, and should be completed once a patient has been diagnosed with IS. Determination of the etiology of IS not only aids in decision making for appropriate treatment for the patient, but is also a useful predictor of the patient's prognosis.
Unfortunately, there is limited data and guidance on the treatment of IS.1 Since there is no gold standard for the management of this disease, most treatment regimens are based on provider preference and experience. Typical first-line medications for the treatment of IS include hormonal therapies, such as adrenocorticotropic hormone (ACTH) and corticosteroids, as well as vigabatrin. Alternative options for the treatment of IS include the ketogenic diet, other anti-epileptic medications, and resective surgery. A suggested treatment algorithm for IS is shown in Figure 1 and Table 2 summarizes all first- and second-line treatment options.