Vigabatrin monotherapy for infantile spasms.

Infantile spasms syndrome (IS) (also known as West syndrome) is an epileptic encephalopathy with a heterogeneous etiology. One of the most common specific causes is tuberous sclerosis, diagnosed in almost 10% of the affected infants. Adrenocorticotropic hormone or steroids have been the preferred treatments for IS for several decades. Clinical studies have shown that vigabatrin is superior to placebo in decreasing the frequency of infantile spasms. In tuberous sclerosis, vigabatrin may be considered the first-line treatment for IS. The mode of action is increasing concentrations of the inhibitory neurotransmitter GABA in the brain. The use of vigabatrin is limited by a serious adverse effect, permanent visual field constriction, which may affect 6-7% of exposed infants. Treatment choices are based on balancing the potential adverse effects against the risk of catastrophic cognitive and behavioral outcomes caused by uncontrolled spasms.