Differential Diagnosis for 44-year-old Male with Liver Transplant

Single Most Likely Diagnosis

• Tacrolimus-induced neurotoxicity: This is a common side effect of tacrolimus, an immunosuppressant used in liver transplant patients. Symptoms can include reduced memory, anger, tremors, and seizures. Given the patient's recent liver transplant and the fact that he is on tacrolimus, this diagnosis is highly plausible.

Other Likely Diagnoses

• Steroid-induced psychiatric symptoms: Although not explicitly mentioned, patients on immunosuppressive regimens post-transplant may receive steroids, which can cause mood swings, anxiety, and cognitive changes. Even if not on steroids currently, previous exposure could contribute to these symptoms.
• Viral encephalitis (e.g., CMV): Valacyclovir is prescribed for prophylaxis against viral infections, but breakthrough infections can occur. Viral encephalitis could present with cognitive decline and mood changes.
• Hypothyroidism: The patient is on levothyroxine, suggesting a history of hypothyroidism. Inadequate thyroid hormone replacement can lead to cognitive symptoms and mood disturbances.

Do Not Miss Diagnoses

• Posterior Reversible Encephalopathy Syndrome (PRES): A potentially life-threatening condition associated with immunosuppressants like tacrolimus, characterized by seizures, hypertension, and visual disturbances, with characteristic MRI findings.
• Central Nervous System (CNS) lymphoma: Although rare, CNS lymphoma is a serious condition that can occur in immunosuppressed patients, presenting with cognitive decline, personality changes, and focal neurological deficits.
• Cerebral vasculitis: A rare but potentially fatal condition that could present with cognitive decline and mood changes in an immunosuppressed patient.

Rare Diagnoses

• Progressive multifocal leukoencephalopathy (PML): A rare and serious demyelinating disease of the CNS caused by the JC virus, which can occur in immunosuppressed individuals, presenting with progressive cognitive decline and focal neurological deficits.
• Wernicke's encephalopathy: A condition caused by thiamine deficiency, which can occur in patients with poor nutrition or increased metabolic demands, such as those post-liver transplant, presenting with confusion, ataxia, and ophthalmoplegia.