Differential Diagnosis for Cognitive Decline with Frontal-Subcortical Network Dysfunction
Single Most Likely Diagnosis
- Autoimmune Encephalitis: The temporal association between the onset of cognitive problems and a viral illness, along with deficits suggesting frontal-subcortical network dysfunction, makes autoimmune encephalitis a strong consideration. This condition is known for its rapid onset and association with viral infections or other immune system triggers.
Other Likely Diagnoses
- Viral Encephalitis: Given the onset of cognitive issues concurrent with a viral illness, direct viral infection of the brain is a plausible cause. Viral encephalitis can present with a range of cognitive and neurological deficits.
- Post-Viral Syndrome or Encephalopathy: Some viral infections can lead to post-viral syndromes that affect cognitive function, potentially through an immune-mediated mechanism rather than direct viral damage.
- Toxic or Metabolic Encephalopathy: Exposure to toxins or metabolic disturbances (e.g., hypoglycemia, hyperglycemia, electrolyte imbalances) can cause cognitive decline and could be considered, especially if there's a history of exposure or systemic illness.
Do Not Miss Diagnoses
- Central Nervous System (CNS) Lymphoma: Although rare, CNS lymphoma can present with cognitive decline and should be considered to avoid missing a potentially treatable malignancy.
- CNS Vasculitis: Inflammatory diseases affecting the blood vessels of the brain can lead to cognitive decline and other neurological symptoms, and are critical to identify due to their treatability.
- Infectious Diseases (e.g., Neurosyphilis, HIV): Certain infectious diseases can cause cognitive decline and have specific treatments, making them important not to miss.
Rare Diagnoses
- Prion Diseases (e.g., Creutzfeldt-Jakob Disease): These are rare, degenerative, and fatal brain disorders that can present with rapid cognitive decline and neurological symptoms.
- Mitochondrial Encephalomyopathies: A group of disorders affecting the mitochondria, which can lead to a variety of neurological symptoms including cognitive decline, though they are less likely given the acute onset described.
- Hashimoto's Encephalopathy: A rare condition associated with Hashimoto's thyroiditis, characterized by cognitive decline and neurological symptoms, which is important to consider due to its responsiveness to treatment.