Idiopathic intracranial hypertension also called pseudotumor cerebri is a rare neurological disorder in children resulting in signs and symptoms of raise intra cranial pressure in the presence of normal brain neuroimaging. The disease is first described by Quincke in 1897 who reported the first cases of IIH shortly after he discovered and introduced LP into medicine . In 1904, the disease was named pseudotumor cerebri but not described until cerebral angiography was added to pneumoencephalography in 1940 . Benign intracranial hypertension is another term of the disease reported by Foley in 1955 but this term “benign” is not applicable any more as the disease may cause permanent loss of vision [4, 5].
The annual incidence of pediatric IIH is about 0.5 per 100, 000 children . The disease most commonly affects obese female as more than 90% of IIH patients are obese and/or in child-bearing age .
The commonest presentation of IIH is by headache, pulsatile tinnitus, transient visual obscurations, and loss of vision [6,7,8]. Children with IIH who is 10 years old or less are most commonly present with strabismus like our patient .
The diagnosis of IIH depends on the presence of all five items of the criteria (Table 1). Our patient was diagnosed as definite IIH as he achieved all five items of the criteria (symptoms and signs of increased intra cranial pressure, no localizing findings in neurological examinations except for false localizing signs, normal brain CT scan and MRI, and high opening pressure > 250 cm H2O with normal CSF constituents).
In order to diagnose patient as having IIH, you should first exclude secondary causes of raise intracranial pressure. Medications like tetracycline, hyper vitaminosis A, steroid thereby, lithium and oral contraceptive pills have been reported in the literature . Obesity, polycystic ovary syndrome, chronic anemia, and leukemias may also be the causative factors [10, 11].
Treatment of IIH should focus on vision protection and reduce the severity of symptoms. A variety of treatments both medical and surgical can help in reducing intracranial pressure. Weight loss can induce disease remission and reduce the severity of headache and papilledema . IIH is not typically associated with obesity or weight gain in pediatrics group, so weigh loss is not recommended in our patient .
Acetazolamide, the most common prescribing agent in IIH, inhibits carbonic anhydrase and therefore lead to decrease CSF production. Vomiting, diarrhea, renal stone, and aplastic anemia are possible side effects. The starting dose is usually 250 mg twice a day. If the patient cannot tolerate acetazolamide, toprimate, another carbonic anhydrase inhibitor, can be used in a dose of 25 mg once daily [6, 7].
Due to its UN favorable side effects, methylepredinsolone is not recommended as long-term management in IIH; however, it can be useful for short-term treatment especially in fulminant disease . (Methylprednisolone may be used as a supplement to acetazolamide to hasten recovery in patients who present with severe papilledema; our patient has grade 4 papilledema. Because of their significant adverse effects, methylprednisolone was prescribed as short-term management). The usual dose of methylepredinsolone is 1 g/day .
Furosemide, a loop diuretic, has also been used alone or in combination with acetazolamide to reduced intracranial pressure in a low dose of 20 mg once or twice per day . Other options includes subtemporal or suboccipital decompression, optic nerve sheath fenestration, CSF shunting procedures, gastric exclusion surgery, and venous sinus stenting which are not available in many resources limited hospitals.
Patients with IIH have a normal life expectancy; the major complication is papilledema which can lead to loss of vision. The most common cause of death is suicide, accidents, and medical or surgical complications .