Differential Diagnosis for Resistant Nausea

Given the normal CT brain, the differential diagnosis for resistant nausea can be categorized as follows:

• Single Most Likely Diagnosis

  • Gastroesophageal reflux disease (GERD) or other gastrointestinal issues: This is a common cause of nausea that may not be immediately apparent and can be resistant to initial treatments. The normal CT brain helps to rule out immediate neurological causes, making gastrointestinal issues more likely.

• Other Likely Diagnoses

  • Viral gastroenteritis: Although often self-limiting, some cases can be prolonged and resistant to typical anti-emetic treatments.
  • Medication side effects: Many medications can cause nausea as a side effect, and this can sometimes be resistant to standard anti-emetic therapies.
  • Functional nausea: Similar to irritable bowel syndrome (IBS), functional nausea can be challenging to treat and may not have an identifiable cause.
  • Endocrine disorders (e.g., thyroid dysfunction, adrenal insufficiency): These can cause nausea among other symptoms and might not be immediately suspected.

• Do Not Miss Diagnoses

  • Pregnancy: Morning sickness can sometimes present atypically and be more severe or prolonged than usual.
  • CNS lesions not visible on CT (e.g., brainstem lesions, early signs of increased intracranial pressure): Although the CT brain is normal, certain conditions might not be visible or could be in early stages not yet detectable by CT.
  • Intra-abdominal pathology (e.g., appendicitis, pancreatitis): These conditions require prompt diagnosis and treatment to prevent serious complications.
  • Metabolic disorders (e.g., diabetic ketoacidosis, uremia): These can cause severe nausea and vomiting and are critical to identify and treat promptly.

• Rare Diagnoses

  • Cyclical vomiting syndrome: A rare condition characterized by recurrent episodes of severe vomiting.
  • Gastroparesis: Delayed stomach emptying can cause nausea and vomiting, especially after eating.
  • Superior mesenteric artery syndrome: A rare condition where the duodenum is compressed by the superior mesenteric artery, causing nausea and vomiting.
  • Neurological conditions like vestibular disorders or migraines: Although less common, these can cause significant nausea and might not always have the typical associated symptoms.