Differential Diagnosis
The patient's symptoms of working memory problems, clumsiness, and relapsing/remitting course, along with the development of psychiatric symptoms and significant appetite increase, suggest a complex and multifactorial condition. The following differential diagnoses are considered:
- Single most likely diagnosis
- Multiple Sclerosis (MS): The relapsing/remitting course, working memory problems, clumsiness, and fatigue are consistent with MS. The development of psychiatric symptoms, such as depression and psychosis, can also occur in MS. The improvement in psychiatric symptoms with medication, but persistence of cognitive symptoms, further supports this diagnosis.
- Other Likely diagnoses
- Neuropsychiatric Systemic Lupus Erythematosus (NPSLE): The patient's symptoms, including working memory problems, psychosis, and depression, can be seen in NPSLE. The relapsing/remitting course and association with a viral illness (norovirus) also support this diagnosis.
- Hashimoto's Encephalopathy: This condition can present with cognitive decline, psychiatric symptoms, and relapsing/remitting course. The association with a viral illness and significant appetite increase/weight gain may also be seen in Hashimoto's Encephalopathy.
- Do Not Miss
- Central Nervous System (CNS) Lymphoma: Although less likely, CNS lymphoma can present with cognitive decline, psychiatric symptoms, and relapsing/remitting course. It is essential to consider this diagnosis due to its potential for severe consequences if missed.
- CNS Infections (e.g., Lyme disease, neurosyphilis): These infections can cause cognitive decline, psychiatric symptoms, and relapsing/remitting course. It is crucial to rule out these infections due to their potential for severe consequences if left untreated.
- Rare diagnoses
- Prion Disease (e.g., Creutzfeldt-Jakob disease): Although rare, prion diseases can present with rapid cognitive decline, psychiatric symptoms, and significant appetite increase/weight gain. The patient's symptoms, particularly the severe working memory problems and aphasia, may suggest a prion disease.
- Mitochondrial Disorders (e.g., MELAS syndrome): These disorders can cause cognitive decline, psychiatric symptoms, and relapsing/remitting course. The association with a viral illness and significant appetite increase/weight gain may also be seen in mitochondrial disorders.