American Board of Internal Medicine (ABIM) Certification Practice Exam

Which medication is specifically used to improve impaired mobility in multiple sclerosis patients?

1. Capsaicin patch

2. Dalfampridine

3. Gabapentin

4. Amantadine

The correct answer is: Dalfampridine

Dalfampridine is specifically indicated for improving mobility in patients with multiple sclerosis (MS). It works by blocking potassium channels, which enhances nerve signal conduction in demyelinated nerves, leading to improved walking speed and mobility. This mechanism is particularly beneficial in MS, where demyelination of the nerves disrupts normal conduction and can lead to significant motor deficits. In contrast, the other medications listed have different primary uses. Capsaicin patches are primarily used for pain relief in neuropathic pain conditions but do not address mobility impairments associated with MS. Gabapentin is primarily used for neuropathic pain and seizures, and while it can have some effects on spasticity, it is not primarily aimed at improving mobility. Amantadine is often used to manage fatigue in MS patients, but it doesn't specifically target mobility enhancement like Dalfampridine does. Thus, Dalfampridine stands out as the medication specifically aimed at improving mobility in those with MS.