An Infantile Spasms Working Group (ISWG) of 14 pediatric neurologists with expertise in IS participated in a 2-day workshop to discuss 1) the current state of IS management, 2) the evidence for efficacy of ACTH and vigabatrin (VGB), approved in the US in 2009, and need for additional alternatives, and 3) to develop protocols as a guide for the diagnostic workup and management of IS. The incidence of IS ranges from 2 to 3.5 per 10,000 live births, and the lifetime prevalence at 10 years of age is lower at 1.5 to 2 per 10,000 children (Trevathan et al, 1999), a result of high mortality. The ISWG discussed the AAP/AAN/CNS consensus statement and practice guideline of 2004, and reviewed the current literature. A consensus was not reached on initial treatment dosage levels, but consensus was strong for the following conclusions:

  1. Need for broad clinical evaluation and diagnostic workup, with overnight inpatient 24-hr video-EEG (awake and all stages of sleep, especially non-REM sleep) conducted as soon as possible after identification of spasms. When EEG hypsarhythmia (Gibbs EL & FA, 1952, preferred spelling) is documented, MRI and other diagnostic tests should be performed and treatment initiated promptly.
  2. ACTH and VGB have proven efficacy and are first-line treatments. VGB is first choice for IS comorbid with tuberous sclerosis, and second or third choice with other symptomatic or cryptogenic IS. Duration of therapy, cumulative dose, and daily dose are implicated as risk factors for visual field changes with VGB; periodic ophthalmic evaluations are recommended in addition to baseline, and at 3-6 months after VGB treatment withdrawal.
  3. Timely assessment of treatment efficacy (2 weeks for ACTH followed by taper; 2 weeks or less following dose titration for VGB). Longer treatment trials are not likely to be effective and may be associated with serious adverse effects.
  4. Response to treatment should be “all or none,“ with complete cessation of spasms and resolution of hypsarrythmia. [1]

COMMENT. In a commentary from Finland on the US consensus report [2], the dangers of prolonged therapy with either ACTH or VGB are emphasized, and the smallest effective doses for 2 weeks are favored.

Fukuyama Y [3], in a commentary from Japan, prefers the term West syndrome to infantile spasms, and notes differences in treatment protocols in US and Japan. In Japan, the dose of ACTH recommended is smaller and the courses, shorter. Vitamin B6 in large doses is advocated as the first-line treatment for newly diagnosed West syndrome patients. VGB is not available in Japan.

Commentaries from Europe and the UK [4] favor a selective diagnostic and therapeutic approach. Given etiologies for IS determine specific clinical/EEG/imaging patterns. Hypoxic-ischemic encephalopathy, a known cause of WS, has a different course for pre-term and full-term infants. IS following preterm delivery of infants with HIE respond well to treatment, whereas HIE-related spasms following full-term delivery tend to be more severe and refractory. Spasms without hypsarrhythmia, but only focal or multifocal spikes, may suggest focal cortical dysplasia or tuberous sclerosis complex as a cause. These authors are impressed with VGB as first-line therapy, and consider the ketogenic diet no more effective than pyridoxine or conventional AEDs. Parents should be informed of the importance of the EEG in diagnosis, and pediatricians made aware of the early manifestations of WS before the onset of typical spasms. A lack of visual contact or awareness in an infant may signal the onset of WS and the need for wake and sleep EEG, if apparent visual impairment is unexplained by ophthalmologic examination. Early diagnosis and treatment appear to be the key to success in the management of West syndrome.