## **Core Concept**
The patient's symptoms, including paresthesias, weakness, band-like sensation of tightness around the torso, painful loss of vision, diplopia, periorbital pain, ataxia, papillitis, facial myokymia, bladder incontinence, and constipation, along with CSF studies showing mononuclear cell pleocytosis and increased IgG, are indicative of **Multiple Sclerosis (MS)**. MS is a chronic autoimmune disease characterized by demyelination in the central nervous system (CNS).

## **Why the Correct Answer is Right**
The condition described is Multiple Sclerosis (MS), a chronic autoimmune disease that affects the CNS. The symptoms and CSF findings are classic for MS. The oral drugs approved for MS include:
- **Fingolimod**: A sphingosine 1-phosphate receptor modulator that reduces lymphocyte circulation into the CNS.
- **Teriflunomide**: An inhibitor of dihydroorotate dehydrogenase, which affects lymphocyte proliferation.
- **Glatiramer acetate**: A synthetic polymer that is thought to act as an immunomodulator.

## **Why Each Wrong Option is Incorrect**
- **Option B: Natalizumab** is incorrect because, although it is used for MS, it is administered via intravenous infusion, not orally. It is a monoclonal antibody against integrin α4β1.
- The question specifically asks for oral drugs.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that for MS, the treatment options have expanded to include oral medications like **Fingolimod**, **Teriflunomide**, and **Glatiramer acetate** (though Glatiramer acetate is typically administered via injection, not orally, making it less likely to be the best answer here). MS treatments aim to reduce relapse rates, delay progression, and manage symptoms.

## **Correct Answer:** B. 1, 3, 4