What is the diagnosis for a 3-week-old infant with fever, seizure, lethargy, and abnormal brain imaging findings?

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Differential Diagnosis for a 3-week-old Boy with Seizure

  • Single most likely diagnosis:
    • Herpes Simplex Virus (HSV) encephalitis: The patient's presentation with seizure, fever, lethargy, and refusal to feed, along with the brain imaging findings of patchy areas of increased attenuation, edema, and hemorrhage in the cerebral cortex, temporal lobe, and brainstem, is highly suggestive of HSV encephalitis. The lack of prenatal care and home delivery may increase the risk of neonatal HSV infection.
  • Other Likely diagnoses:
    • Bacterial meningitis: The patient's symptoms of fever, lethargy, and seizure, along with the full anterior fontanel, could indicate bacterial meningitis. The pending lumbar puncture results will help confirm or rule out this diagnosis.
    • Sepsis: The patient's fever, lethargy, and refusal to feed could be indicative of sepsis, which can cause seizures and neurological symptoms.
  • Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
    • Intracranial hemorrhage: Although the brain imaging did not show intracranial calcifications, it did reveal edema and hemorrhage in the left temporal lobe and brainstem. It is essential to consider and investigate further to rule out any underlying vascular malformations or other causes of hemorrhage.
    • Metabolic disorders: Certain metabolic disorders, such as pyridoxine-dependent epilepsy, can cause seizures in neonates. Although less likely, it is crucial to consider and investigate these disorders to provide appropriate treatment.
  • Rare diagnoses:
    • Congenital infections (e.g., toxoplasmosis, rubella, CMV): Although less likely due to the lack of intracranial calcifications, congenital infections can cause neurological symptoms and seizures in neonates.
    • Mitochondrial disorders: Rare mitochondrial disorders, such as Alpers-Huttenlocher syndrome, can cause seizures, developmental delay, and progressive neurological deterioration in infants.
    • Arteriovenous malformation (AVM) or other vascular anomalies: Although rare, AVMs or other vascular anomalies can cause seizures, hemorrhage, and neurological symptoms in neonates.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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