Clinical and imaging features of idiopathic intracranial hypertension

Idiopathic intracranial hypertension (IIH) is a syndrome that excludes secondary causes such as intracranial space-occupying lesion, hydrocephalus, cerebrovascular disease, and hypoxic ischemic encephalopathy. If not be treated promptly and effectively, IIH can cause severe, permanent vision disability and intractable, disabling headache. This study aims to explore the clinical and image features for IIH, to help clinicians to understand this disease, increase the diagnose rate, and improve the outcomes of patients.

We retrospectively analyzed 15 cases of IIH that were admitted to Xiangya Hospital, Central South University, during January 2015 to September 2020. The diagnosis of IIH was based on the updated modified Dandy criteria. We analyzed clinical data of patients and did statistical analysis, including age, gender, height, weight, medical history, physical examination, auxiliary examination, treatment and outcome.

There were 10 females and 5 males. Female patients were 22 to 42 years old with median age of 39.5. Male patients were 27 to 52 years old with the median age of 44.0. The BMI was 24.14-34.17 (28.71±2.97) kg/m². All patients had a BMI above the normal range (≥24 kg/m²), among them 10 cases (66.7%) were obese, and 5 cases (33.3%) were overweight. Eleven cases (73.3%) had headache, and 8 cases (53.3%) had persistent visual loss of different severity. Other symptoms included paroxysmal amaurosis (2 cases), tinnitus (3 cases), horizontal diplopia (2 cases), unilateral peripheral facial paralysis (2 cases), and unilateral blepharoptosis (1 case). Iron-deficiency anemia was found in 3 patients. One of them fully recovered from IIH after the correction of anemia. Other comorbidities included hypertension (8 cases) and polycystic ovarian syndrome (1 case). Fourteen patients assessed blood lipid profile, and all of them had abnormity. Nervous system signs included cervical rigidity (2 cases), limited abduction of eyeball (6 cases), peripheral facial paralysis (2 cases), and blepharoptosis (1 case). Cerebral spinal fluids of all patients had normal cell count, chemical component, Gram's stain, acid-fast stain, and India ink stain. Typical image signs suggesting that IIH could be seen in some patients, including empty sella (5 cases, 33.3%) or partially empty sella (4 cases, 26.7%), distension of perioptic subarachnoid space (3 cases, 20%), flattening of the posterior sclera (5 cases, 33.3%), intraocular protrusion of the optic papilla (7 cases, 46.7%), and enhancement of the optic papilla (2 cases, 13.3%). Ophthalmic exam showed all patients had bilateral papilledema. After diagnosed as IIH, all patients received individualized dehydration treatment to reduce the intracranial hypertension. Three patients received the ventriculo-peritoneal shunt operation. Most patients had good outcome after treatment. For 2 patients, visual impairment was poorly recovered.

IIH primarily affects women of childbearing age who are overweight. The major hazard of IIH is the severe and permanent visual loss. Typical image signs have high specificity in IIH diagnosis. Prompt diagnosis and effective treatment are significantly important to improve the outcomes of patients.