ABSTRACT
Primary intracranial hypertension (PIH) is characterized by clinical signs of increased intracranial pressure, papilledema, elevated opening pressure, and absence of mass lesion, hydrocephalus, or meningeal enhancement on neuroimaging. Visual changes are a common presenting feature and if untreated there is risk of irreversible vision loss. There have been recent proposed changes to the criteria for PIH along with studies looking at the differences in imaging characteristics between adult and pediatric PIH. The presence of transverse sinus stenosis alone was highly sensitive and specific for pediatric PIH. The Idiopathic Intracranial Hypertension Treatment Trial was an adult, multicenter study that examined the use of acetazolamide and weight loss on the course of PIH. The study confirmed many previously held beliefs including the most common presenting symptom in PIH is headache. Most patients present with bilateral papilledema with 58.2% of patients having symmetric Frisen scale grading and within one grade in 92.8%. Although diplopia is a common reported symptom, very few have evidence of cranial nerve palsy. Male gender, high-grade papilledema, and decreased visual acuity at presentation are risk factors for treatment failure. Acetazolamide use is associated with mild metabolic acidosis. During acetazolamide treatment, monitoring for hypokalemia or aplastic anemia is not recommended. Monitoring transaminases in the titration phase of treatment should be considered due to a case of transaminitis and pancreatitis with elevated lipase. Newer case reports have also seen associations of secondary intracranial hypertension with concurrent COVID-19 infection and MIS-C.