Differential Diagnosis

Given the scenario of a single episode with no recurrence, unremarkable MRI brain and EEG, normal neuro exam, and normal development, the differential diagnosis can be organized as follows:

• Single Most Likely Diagnosis
  • Benign Rolandic Epilepsy: This condition is characterized by seizures that often occur at night and can manifest with facial and oropharyngeal symptoms. It's a common form of epilepsy in children, typically with a good prognosis, normal development, and often normal EEGs between episodes.
• Other Likely Diagnoses
  • Febrile Seizure: Although typically associated with fever, some febrile seizures can occur without a clear fever at the time of the seizure. The normal development and lack of recurrence make this a plausible consideration.
  • Acute Symptomatic Seizure: This refers to a seizure that occurs in close temporal relationship to an acute systemic or neurological insult. The cause could be metabolic, toxic, or due to an acute infection, among others. The fact that there's no recurrence and all tests are normal suggests the insult may have been transient and fully resolved.
• Do Not Miss Diagnoses
  • Intracranial Hemorrhage or Arteriovenous Malformation (AVM): Although the MRI was unremarkable, the possibility of a small, undetected lesion or a condition that doesn't show up well on MRI (like some AVMs) cannot be entirely ruled out without considering other diagnostic modalities or clinical correlation.
  • Meningitis or Encephalitis: Infections of the CNS can present with seizures, and while the lack of fever or other symptoms makes this less likely, missing such a diagnosis could be catastrophic.
• Rare Diagnoses
  • Mitochondrial Disorders: These are a group of disorders caused by dysfunctional mitochondria, which can lead to a wide range of neurological symptoms, including seizures. They are rare and often have a more complex presentation, but could be considered in the differential for a single, unexplained seizure episode.
  • Genetic Epilepsy Syndromes: There are numerous genetic syndromes that can cause epilepsy, some of which may have a relatively benign course. The normal development and single seizure episode might suggest a milder form of one of these syndromes.