Drug of choice for infantile spasms in a patient with tuberous sclerosis is:
**Core Concept**
Tuberous sclerosis complex (TSC) is a genetic disorder characterized by the growth of non-cancerous tumors in various organs, including the brain. Infantile spasms, also known as West syndrome, is a severe form of epilepsy that affects infants and young children. The management of infantile spasms in TSC patients often requires specific pharmacological interventions.
**Why the Correct Answer is Right**
Adrenocorticotropic hormone (ACTH) is the drug of choice for infantile spasms in patients with tuberous sclerosis. ACTH exerts its antiepileptic effects by increasing the production of cortisol, which has a neuroprotective effect. The exact mechanism of ACTH in treating infantile spasms is not fully understood, but it is thought to involve the modulation of glutamate and GABA neurotransmission, as well as the reduction of inflammation in the brain. The use of ACTH is supported by several studies, including the multicenter trial conducted by the North American Epilepsy Research Foundation.
**Why Each Wrong Option is Incorrect**
* **Option A:** Vigabatrin is an antiepileptic medication used in the treatment of infantile spasms, but it is not the first-line treatment for patients with tuberous sclerosis. Vigabatrin is effective in reducing seizures in some patients, but its use is limited by the risk of vision loss.
* **Option B:** Topiramate is another antiepileptic medication that has been used to treat infantile spasms, but it is not the preferred treatment for patients with TSC. Topiramate has a broad spectrum of antiepileptic activity, but its efficacy in treating infantile spasms is not as well established as that of ACTH.
* **Option D:** Levetiracetam is a newer antiepileptic medication that has been used to treat a variety of seizure disorders, including infantile spasms. However, it is not the first-line treatment for patients with TSC, and its efficacy in treating infantile spasms is not as well established as that of ACTH.
**Clinical Pearl / High-Yield Fact**
The use of ACTH in treating infantile spasms in patients with TSC is supported by a significant body of evidence, including several multicenter trials. ACTH is typically administered at a dose of 40-60 IU/day for 2-4 weeks, followed by a gradual tapering of the dose. Close monitoring of the patient's response to treatment is essential, as ACTH can have significant side effects, including hyperglycemia and adrenal suppression.
**Correct Answer:** C. ACTH.