Vigabatrin for tuberous sclerosis complex

Short answer: vigabatrin is the first-choice medicine for infantile spasms caused by tuberous sclerosis complex (TSC). It stops spasms in a much larger share of babies with TSC than in babies with other causes, and guidelines around the world agree on it.^1,2 Giving it before seizures start is still debated: one trial (EPISTOP) found clear seizure benefits and another (PREVeNT) found no benefit for development or focal seizures.^3,4

Infantile spasms are one of the seizure types seen in babies with TSC. This page covers what the research shows about vigabatrin in TSC. Treatment decisions belong with the child's neurologist.

Why vigabatrin is the first choice in TSC

For most babies with infantile spasms, hormonal treatment (ACTH or oral steroids) works better than vigabatrin alone.⁵ TSC is the exception, and the evidence for that is consistent:

• A small trial (1997). Babies with TSC were given either vigabatrin at 150 mg/kg/day or hydrocortisone, a steroid. Spasms stopped in all 11 on vigabatrin and in 5 of 11 on hydrocortisone. On average, spasms stopped after 3.5 days on vigabatrin against 13 days on hydrocortisone. All 7 babies who switched to vigabatrin were then controlled.⁶
• An early review (1999). Pooling published reports, spasms stopped completely in 73 of 77 babies with TSC (95%), against 170 of 313 without TSC (54%).¹
• The US trial. In the main US vigabatrin trial, babies with TSC responded faster than other babies.⁷
• A systematic review (2023). Across 17 studies of vigabatrin in TSC, 67% of babies responded overall, and 88% were spasm-free in the randomized trials. The authors note that the evidence is low level and the studies differ a lot.⁸
• A meta-analysis (2023). Vigabatrin worked much better in TSC than in other causes of spasms (odds ratio 5.59).⁵
• Cochrane review (2013). "Vigabatrin may be the treatment of choice in tuberous sclerosis."⁹
• Guidelines (2026). A review of 28 guidelines from around the world found that vigabatrin was recommended as first-line treatment for spasms caused by TSC in every one.²

The approved dose for infantile spasms starts at 50 mg/kg/day and can rise to 150 mg/kg/day, split into two doses.¹⁰ See dosage and vigabatrin for infantile spasms.

Preventive treatment before seizures

Some babies are known to have TSC before any seizures start. That raises a question: should vigabatrin be started early, to prevent seizures or to protect development? Two randomized trials have tested this, and they point in different directions.

EPISTOP (2021)

EPISTOP included 94 infants with TSC. It compared preventive vigabatrin, started before seizures, with conventional treatment, started once seizures began.³

• The first seizure came later with preventive treatment: after 364 days vs 124 days in the randomized part, and 426 vs 106 days in the open-label part.
• At 24 months, preventive treatment lowered the risk of clinical seizures (odds ratio 0.21) and of drug-resistant epilepsy (odds ratio 0.23).
• No baby on preventive treatment developed infantile spasms (p under 0.001).³

PREVeNT (2023)

PREVeNT randomly assigned 56 infants with TSC to vigabatrin (29) or placebo (27) before seizures began.⁴

• Development (cognition) at 24 months was the same in both groups.
• There was no difference in how many children developed epilepsy or drug-resistant epilepsy.
• Infantile spasms were less common, and started later, with vigabatrin.⁴

Reading the two together

Both trials found fewer infantile spasms with early vigabatrin. They differ on the rest: EPISTOP found fewer seizures and less drug-resistant epilepsy, while PREVeNT found no benefit for development, epilepsy overall or drug-resistant epilepsy.^3,4 Both trials were small. Preventive use is not part of the FDA label, which covers infantile spasms in babies 1 month to 2 years old and add-on treatment of refractory complex partial seizures from age 2.¹¹

The full papers are available here: PREVeNT trial (open-access PDF, CC BY-NC) and EPISTOP trial (open-access PDF, CC BY-NC). See research for plain-language summaries.

EEG screening in TSC

An EEG is a recording of the brain's electrical activity. The 2021 international TSC consensus recommendations put more emphasis on early EEG screening of infants for epileptic activity.¹² Ask your child's TSC team how often EEGs are planned and what would lead them to start treatment.

Vision monitoring

The vision-loss warning applies to children with TSC like everyone else. Risk rises with dose and with total exposure, and no dose is free of risk.¹⁰ In one international follow-up study of children treated for infantile spasms, visual field defects were found at school age in 6 of the 10 children with TSC. The numbers are small, and defects were also more common with longer treatment.¹³

Eye checks are required at baseline (no later than 4 weeks after starting), at least every 3 months on treatment, and about 3 to 6 months after stopping.¹⁰ See vision loss and REMS.

Kidneys and TSC

Vigabatrin leaves the body mainly through the kidneys, so poor kidney function raises blood levels.¹⁴ One case report describes a patient with TSC and kidney failure who became agitated on 3 g a day. The inactive form of the drug had built up, and hemodialysis removed both forms.^14,15 The label lowers the dose for reduced kidney function in patients 2 years and older.¹⁶ See dosage.

Which form to use

Babies with spasms from TSC use an oral solution: powder mixed with water before each dose, or the ready-to-use liquid, which is labeled for infantile spasms from 1 month to 2 years.^10,11 Children 2 and older with TSC who take vigabatrin as add-on treatment for refractory complex partial seizures use tablets or powder. See liquid vs powder.

Support for families

These groups support families living with TSC. This site has no tie to any of them and is not responsible for their content.

• TSC Alliance community support network
• Tuberous Sclerosis Association (TSA)
• TSC Alliance online discussion group on Facebook
• r/TuberousSclerosisComp on Reddit