History: A 63-year-old woman presents with headaches, nausea, vomiting, and vertigo.(63岁妇女,出现头痛、恶心、呕吐和眩晕。)
Sagittal T1-weighted MR image shows an empty and expanded sella turcica.
Axial T2 images show the optic nerve sheath is widened and expanded with cerebrospinal fluid (CSF) hyperintensity surrounding the optic nerve.
Axial T2 and axial FLAIR images shows posterior flattening of the globes.
正确诊断：Idiopathic intracranial hypertension (IIH)（特发性颅内高压）
Idiopathic intracranial hypertension (IIH)
As the name suggests, the exact cause of idiopathic intracranial hypertension is not fully understood. The diagnosis is dependent upon exclusion of other causes of intracranial hypertension, including mass lesions and hydrocephalus. Pseudotumor cerebri refers to patients with raised intracranial pressure without hydrocephalus or mass lesion but which may be secondary to findings such as dural sinus thrombosis or dural arteriovenous fistula. There are several theories regarding IIH’s pathophysiology, which include the following:
Impaired CSF homeostasis (reduced CSF reabsorption or excess CSF production)
Altered vitamin A metabolism, supported by associations with medications including tetracycline and corticosteroids
Venous sinus stenosis, which may cause increased venous pressures, leading to decreased CSF resorption, increased ICP and venous sinus compression
Idiopathic intracranial hypertension is a rare condition, with an incidence of approximately 0.9 cases per 100,000. It is found much more commonly in women with a reported 8:1 female to male ratio. There is a strong association with body mass index (BMI), such that the odds ratio of the condition increases approximately fourfold with a BMI greater than 35 compared with a BMI of 25-29. It occurs most commonly between the ages of 20 and 44. It is also associated with the use of growth hormones, steroids, tetracycline, vitamin A, thyroid replacement, and some systemic diseases, including hypercoagulability disorders, systemic lupus erythematosus, Addison’s disease, and severe iron deficiency anemia.
Classically, idiopathic intracranial hypertension presents with headache and vision changes in obese women of childbearing age. Headaches are usually unremitting, associated with retro-ocular pain and accompanied by nausea. Vision changes usually include tunnel vision secondary to transient ischemia of the optic nerve. Ophthalmologic signs of IIH include diminished visual acuity and visual field losses on formalized testing, as well as papilledema on fundoscopic exam in 40% of patients. Cranial nerve palsies, usually the abducens nerve (CN VI), can occur in as many as 10% to 20% of patients.
“Empty sella sign” — Refers to when the pituitary gland is not visible and is associated with longstanding effects of increased intracranial pressure.
Optic nerve sheath enlargement with widened ring of CSF signal intensity around the side of the optic nerve
Posterior globe flattening, which is associated with increased ocular pressure by transmission of elevated CSF pressure through the optic nerve sheath to the posterior globe, and is associated with the finding of papilledema
Optic nerve tortuosity
Intraocular protrusion of the optic nerve head
Stenosis of the transverse cerebral venous sinuses
The main goals of treatment are to alleviate symptoms of increased intracranial pressure (largely headaches) and preserve vision.