American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the pharmacologic treatment suggested for Pseudobulbar affect in multiple sclerosis?

1. Dextromethorphan-quinidine

2. Sertraline

3. Lamotrigine

4. Gabapentin

The correct answer is: Dextromethorphan-quinidine

Pseudobulbar affect (PBA) is a neurological condition characterized by involuntary episodes of laughing or crying that are disproportionate or incongruent to the individual's emotional state. This phenomenon is often observed in conditions such as multiple sclerosis (MS) and can significantly impair quality of life. The pharmacologic treatment recommended for PBA in patients with multiple sclerosis is dextromethorphan-quinidine. Dextromethorphan, an antitussive agent, acts on the CNS to reduce the frequency and severity of these emotional outbursts. When combined with quinidine, which inhibits the metabolism of dextromethorphan, the two together enhance its efficacy while minimizing side effects. While other medications like sertraline (an SSRI), lamotrigine (a mood stabilizer), and gabapentin (an antiepileptic) may be utilized for mood disorders or neuropathic pain associated with MS, they are not indicated specifically for the treatment of PBA. Their mechanisms of action do not target the dysregulation of emotional expression seen in PBA as effectively as dextromethorphan-quinidine. Thus, for managing pseudobulbar affect in multiple sclerosis, dextrom