Also known as: AIP
Mark presents with abdominal pain, mood swings, fainting episodes, and progressive paralysis. House diagnoses acute intermittent porphyria after triggering an attack with a barbiturate/alcohol/protein cocktail to collect urine during symptoms. The condition causes axonal nerve death and was initially misdiagnosed as several other conditions including Alzheimer's and Guillain-Barré syndrome.
Also known as: Bladder dysfunction
Found during exploratory surgery showing distended bladder, ultimately revealed to be a symptom of the underlying porphyria affecting his nervous system.
Also known as: Nerve damage, numbness
Mark develops numbness, tingling, and eventual paralysis of his extremities as the porphyria attacks his peripheral nervous system, mimicking Guillain-Barré syndrome.