Management of infantile spasms

Abstract

West syndrome, or infantile spasms syndrome is a frequently catastrophic infantile epileptic encephalopathy with a variety of etiologies. Despite the heterogeneous nature of causes of infantile spasms, a careful diagnostic evaluation can lead to diagnosis in many patients and may guide treatment choices. Magnetic resonance imaging (MRI) brain remains the highest yield initial study in determining the etiology in infantile spasms. Treatment of infantile spasms has little class I data, but adrenocorticotropic hormone (ACTH), prednisolone and vigabatrin have the best evidence as first-line medications. Other therapies including the ketogenic diet and other anti-epileptics medications may also prove useful in the treatment of infantile spasms. In general, more studies are needed to determine the best treatment regimen for this condition. Prognosis is generally poor, with the majority of patients having some or profound neurocognitive delays. Patients without delays at diagnosis and without an identifiable etiology, if treated appropriately, have the greatest likelihood of a normal outcome.

Keywords: Infantile spasms; West syndrome; adrenocorticotropic hormone (ACTH); corticosteroids; hypsarrhythmia.

Figure 1

Diagnostic algorithm for infantile spasms. As noted, imaging has the highest yield, followed by genetic studies. *, Patients with a convincing history of infantile spasms and abnormalities other than hypsarrhythmia on EEG, may proceed to imaging without repeat EEG. If the concern for infantile spasms is significant and development is affected, it is not recommended to wait for EEG abnormalities, as up to 1/3 of patients may not have hypsarrhythmia. Treatment should begin once imaging is complete unless there is concern for infection and other work-up is needed. EEG, electroencephalogram; MRI, magnetic resonance imaging; ACTH, adrenocorticotrophic hormone; SNP, single nucleotide polymorphism; CGH, comparative genomic hybridization.

Figure 2

Treatment algorithm. Suggested sequence of treatment, with etiology incorporated. Data is inadequate to recommend a consistent first-line therapy, except in the case of tuberous sclerosis. It is recommended to try two first-line therapies before moving on to other options, as there is less data to support the second-line treatments. Studies have reported patients that respond to ACTH after failing corticosteroids and vice-versa. TSC, tuberous sclerosis complex; ACTH, adrenocorticotropic hormone; EEG, electroencephalogram.