![]() ![]() Other studies have suggested a role for vitamin A in IIH pathogenesis based on elevated serum and CSF vitamin A, retinol, and retinol binding protein levels reported in IIH patients.However, this hypothesis is unable to explain its presence among the non-obese population group. Some suggested that an increase in intraabdominal pressure, secondary to obesity, causes increased cardiac filling pressure which impedes venous return from the brain and subsequently leads to an elevated intracranial venous pressure and IIH.However, it is not clear from current literature whether the venous sinus stenosis is the primary cause of the elevated ICP, secondary to the elevated ICP, or an incidental finding. demonstrated evidence of bilateral venous sinus stenosis in 93% of IIH patients compared to 7% of controls, and numerous other studies have corroborated these findings. This stenosis can result in cerebral venous hypertension and impaired CSF absorption. Another proposed mechanism involves stenosis of the distal portion of the transverse venous sinuses.Furthermore, no pathologic signs of cerebral edema were documented in these patients. However, it was quickly criticized because the elevated ICP was not associated with altered levels of alertness, cognitive impairments, or focal neurologic findings typically seen with cerebral edema. Cerebral edema was one of the earliest proposed pathological mechanisms for IIH.The pathophysiology remains unclear but multiple hypotheses have been suggested. Associated conditions include migraines and Down syndrome. ![]() It is important to note that among pre-pubertal pediatric patients, there is no predilection towards females and more commonly these patients have normal body mass index. In addition to systemic illnesses, certain medications have also been associated with IIH, including tetracyclines, vitamin A, lithium, anabolic steroids, oral contraceptive pills, nalidixic acid, and cyclosporine. The underlying mechanisms of these associations are not yet fully understood. IIH also has no particular predilection for race, but race may impact visual prognosis in these patients.Īmong other possible risk factors, certain systemic illnesses have been associated with IIH, including obstructive sleep apnea, hypothyroidism, anemia, Addison disease, systemic lupus erythematosus, Behçet's syndrome, polycystic ovary syndrome, coagulation disorders, and uremia. Interestingly, in the prepubertal age group, IIH has no particular predilection for obesity or female gender. While males are less frequently affected, constituting less than 10% of adult IIH patients, the affected population also tend to be obese and are more likely to sustain worse visual prognosis compared to their female counterparts. IIH may be seen in any gender or age group but has a high predilection for females of childbearing age, especially when coupled with obesity. The disease incidence is variable throughout the world mainly because its occurrence varies according to the incidence of obesity in the region. Among studies performed in the United States, the incidence of IIH was found to be 0.9 to 1.0 per 100,000 in the general population, increasing to 1.6-3.5 per 100,000 in women and to 7.9-20 per 100,000 in overweight women.
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