Differential Diagnosis for Dorsal Pons and Corpus Callosum Hypertension on MRI

Single Most Likely Diagnosis

• Multiple Sclerosis (MS): This is a leading consideration due to the involvement of the dorsal pons and corpus callosum, which are common sites for MS lesions. The appearance of hypertensive lesions in these areas on MRI, particularly in a young adult, strongly suggests MS.

Other Likely Diagnoses

• Acute Disseminated Encephalomyelitis (ADEM): Although less common than MS, ADEM can present with similar MRI findings, including lesions in the brainstem and corpus callosum. It tends to occur after a viral infection or vaccination.
• Neuromyelitis Optica Spectrum Disorder (NMOSD): This condition can cause lesions in the brainstem, including the dorsal pons, and can also affect the corpus callosum. The presence of aquaporin-4 antibodies would support this diagnosis.
• Central Nervous System Lymphoma: This can present with lesions in the corpus callosum and brainstem, although it is less common than demyelinating diseases.

Do Not Miss Diagnoses

• CNS Vasculitis: This includes conditions like primary CNS vasculitis or secondary vasculitis due to systemic diseases (e.g., lupus). Vasculitis can cause a wide range of neurological symptoms and can be fatal if not treated promptly.
• Infectious Processes (e.g., Abscess, Encephalitis): Certain infections can cause focal lesions in the brainstem and corpus callosum. Identifying and treating these conditions early is crucial to prevent serious complications or death.
• Metastatic Disease: Although less likely, metastases to the brain can occur in the corpus callosum and brainstem. A thorough cancer screening is essential in patients with a known history of cancer.

Rare Diagnoses

• Leukodystrophies: These are a group of rare, genetic disorders that affect the growth or maintenance of the myelin sheath. They can present with progressive neurological deterioration and characteristic changes on MRI.
• Mitochondrial Encephalomyopathies: Conditions like MELAS (Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-like episodes) can cause lesions in the brainstem and corpus callosum, although they are typically associated with more widespread neurological and systemic symptoms.
• Marchiafava-Bignami Disease: A rare condition characterized by demyelination of the corpus callosum, often associated with alcohol abuse.