Multiple sclerosis (MS) is a chronic autoimmune demyelinating disease of the central nervous system (CNS), commonly presenting with optic neuritis, motor dysfunction, or sensory disturbances. However, intractable hiccups as an initial manifestation are exceedingly rare. Early recognition of such atypical symptoms is crucial for timely diagnosis and intervention. A 19-year-old woman presented with intractable hiccups and progressive numbness affecting her right arm and trunk. Neurological examination revealed right upper limb weakness, sensory impairment from the clavicle to the upper abdomen, and hyperreflexia in the right lower limb. Brain MRI demonstrated a hyperintense lesion in the dorsal medulla on axial T2-weighted imaging, with mild enhancement on contrast-enhanced T1-weighted imaging. Cervical spine MRI showed a high-intensity lesion extending from C2 to C6. Serological tests for aquaporin-4 (AQP4)-IgG and myelin oligodendrocyte glycoprotein (MOG)-IgG were negative. Based on her clinical and imaging findings, a diagnosis of MS was established according to the 2017 McDonald criteria. She was treated with high-dose corticosteroids followed by ofatumumab (Kesimpta®), a B-cell depletion therapy, leading to significant symptom improvement. This case underscores the need to recognize intractable hiccups as a potential brainstem symptom of MS. Furthermore, we discuss the challenges in diagnosing oligoclonal band-negative MS and the potential role of alternative biomarkers such as neurofilament light chain (NfL). Early diagnosis and appropriate management can improve patient outcomes, particularly in cases involving the brainstem.