**Core Concept**
Infantile spasms, also known as West syndrome, is a severe form of epilepsy that affects infants. Tuberous sclerosis is a genetic disorder that can cause infantile spasms and other neurological problems. The treatment of infantile spasms in the context of tuberous sclerosis requires a specific medication that has been shown to be effective in this population.

**Why the Correct Answer is Right**
Vigabatrin is the drug of choice for infantile spasms in children with tuberous sclerosis. It works by inhibiting the enzyme GABA transaminase, which breaks down the neurotransmitter gamma-aminobutyric acid (GABA). GABA is an inhibitory neurotransmitter that helps to calm down neuronal activity. By increasing the levels of GABA in the brain, vigabatrin helps to reduce the frequency and severity of seizures. The use of vigabatrin in tuberous sclerosis has been specifically approved by regulatory agencies, including the US FDA, due to its efficacy in this population.

**Why Each Wrong Option is Incorrect**
**Option A:** Topiramate is an antiepileptic medication that can be used to treat various types of seizures, but it is not the first-line treatment for infantile spasms in tuberous sclerosis.
**Option B:** Phenytoin is an older antiepileptic medication that can be used to treat tonic-clonic seizures, but it is not effective in treating infantile spasms and can actually worsen the condition in some cases.
**Option C:** Lamotrigine is an antiepileptic medication that can be used to treat various types of seizures, but it is not the preferred treatment for infantile spasms in tuberous sclerosis.

**Clinical Pearl / High-Yield Fact**
Remember that the treatment of infantile spasms in tuberous sclerosis requires a specific medication that has been shown to be effective in this population. Vigabatrin is the only medication that has been specifically approved by regulatory agencies for this indication, and it should be used as the first-line treatment.

**Correct Answer: C. Vigabatrin**