Idiopathic intracranial hypertension.

The syndrome of intracranial hypertension without structural brain or cerebrospinal fluid abnormalities and without identifiable cause, now most appropriately termed idiopathic intracranial hypertension, was described over a century ago. Although the pathogenesis of this condition remains unknown, diagnostic and therapeutic developments during the past two decades have substantially advanced patient management.     

Idiopathic intracranial hypertension

Although the cause of IIH remains obscure, loss of visual function is common, and patients may progress to blindness. Diagnosis should adhere to the modified Dandy criteria. Recent case-control studies cast doubt on the validity of many frequently cited conditions associated with IIH. Valid associations include obesity, recent weight gain, female sex, vitamin A intoxication, and steroid withdrawal. Management should include serial perimetry using a sensitive disease-specific strategy so the proper therapy can be selected and visual loss prevented or reversed.     

Idiopathic intracranial hypertension

Dhungana S, Sharrack B, Woodroofe N. Idiopathic intracranial hypertension.
Acta Neurol Scand: 2010: 121: 71–82.
© 2009 The Authors Journal compilation © 2009 Blackwell Munksgaard. Idiopathic intracranial hypertension (IIH) is a condition which affects predominantly overweight women and is characterized by raised intracranial pressure without any identifiable pathology in the brain and with normal cerebrospinal fluid (CSF) composition. The cause of IIH is unclear and as such it remains a diagnosis of exclusion. Although the pathophysiology of IIH remains elusive, some observations have recently been added to our understanding of this, including the presence of transverse sinus stenosis on many patients and the possible role of leptin and inflammation in the disease pathogenesis. Headache is the most common symptom and papilloedema is the major clinical finding. Choices of medical treatment are limited to the use of diuretics particularly acetazolamide and encouragement of weight loss. Surgical therapies such as CSF diversion procedures and fenestration of the optic nerve may be necessary in some cases with persistent symptoms or progressive visual deterioration. While not life‐threatening, IIH has a significant morbidity with up to 25% of patients developing visual impairment from optic atrophy. Visual surveillance is therefore vital. Long‐term follow‐up is recommended as the disease may worsen after an initial period of stability.     

Idiopathic intracranial hypertension

Idiopathic intracranial hypertension is common in obese women and can lead to significant visual impairment. First described more than 100 years ago, the cause of the disorder remains unknown. Despite a multitude of proposed links, the aetiology has never been established. Impairment of cerebrospinal-fluid reabsorption is the most likely underlying pathophysiological cause of the raised pressure, but this notion has yet to be proven. Cerebral venous sinus abnormalities associated with the disorder need further exploration. Although the major symptoms of headache and visual disturbance are well documented, most data for disease outcome have been from small retrospective case series. No randomised controlled trials of treatment have been done and the management is controversial. The importance of weight loss needs clarification, the role of diuretics is uncertain, and which surgical intervention is the most effective and safe is unknown. Prospective trials to examine these issues are urgently needed.     

Idiopathic intracranial hypertension without papilledema

We describe 10 patients with idiopathic intracranial hypertension who did not have papilledema. Idiopathic intracranial hypertension without papilledema, although rarely reported, may well be a clinically important headache syndrome. Historical and demographic features of patients with idiopathic intracranial hypertension without papilledema are similar to those of patients with papilledema. Obese women with chronic daily headache and symptoms of increased intracranial pressure, pulsatile tinnitus, history of head trauma or meningitis, an empty sella on imaging studies, or a headache that is unrelieved by standard therapy should have a diagnostic lumbar puncture. Findings from laboratory and neurologic investigations are normal in most patients with idiopathic intracranial hypertension without papilledema. Initial management should include removal of possible inciting agents, weight loss if applicable, and standard headache therapy. Lumbar puncture and diuretic therapy should precede a trial of corticosteroids. Surgery (lumboperitoneal or ventriculoperitoneal shunt or perhaps optic nerve sheath fenestration) may be indicated for prolonged incapacitating headache that is not responsive to medical management or lumbar puncture.     

Idiopathic intracranial hypertension in pregnancy

Objective Since idiopathic intracranial hypertension (IIH) is most prevalent in obese women of childbearing age, concerns arise regarding the impact of pregnancy on the disorder and the potential teratogenicity of some therapeutic agents. We evaluated the course, management of pregnant IIH patients and the visual and pregnancy outcomes. Methods Case series of pregnant women diagnosed with IIH. IIH symptoms, neuro-ophthalmological findings, IIH management, visual and pregnancy outcomes were documented. Results Among 240 women with IIH, 12 had 16 pregnancies. Ten had headaches, five had transient visual obscurations, and three had diplopia. Visual acuity was severely decreased in one and mildly reduced in three women. Six had marked and six had mild bilateral papilledema. Visual field loss occurred in four women. Visual symptoms and loss improved for the duration of the pregnancy after diagnostic lumbar puncture and salt restricted diet in three. Two additional women needed continuous spinal drainage for two days. One woman was treated with acetazolamide and medical abortion. The one woman with severe vision loss had fenestration of one optic nerve sheath and a lumboperitoneal shunt as well as corticosteroids and was the only case with permanent field loss. After intervention, visual acuity improved in all cases with reduced vision. There were 10 full-term normal deliveries, three missed abortions, one therapeutic abortion and two intrauterine fetal deaths. Conclusions IIH appears to present during the first two trimesters of pregnancy with typical symptoms and findings. Visual outcome is similar as for non-pregnant women. Treatment should be oriented towards dietary control, without ketosis. Repeated spinal fluid drainage, if needed, can be helpful. Received: 29 November 2001 Received in revised form: 14 February 2002 Accepted: 18 February 2002     

Idiopathic intracranial hypertension in children

We studied prospectively the etiology, clinical presentation, and outcome of idiopathic intracranial hypertension in 36 patients (20 boys and 16 girls) aged 3.5 months to 14 years. The etiology was identified in 28 (77.7%) patients. The most common predisposing factor was middle-ear infection, followed by obesity. Of the 36 cases seen, 26 presented with the classic picture of headaches, papilledema, and elevated cerebrospinal fluid pressure; 8 children had intracranial hypertension in the absence of papilledema and 2 had fundoscopic evidence of papilledema with normal cerebrospinal fluid pressure initially. In four children resolution of intracranial hypertension occurred with removal of the causative agent or appropriate treatment of the underlying condition. In 8 of 17 patients intracranial hypertension resolved with acetazolamide therapy and in 22 of 24 patients it resolved with corticosteroids in combination with acetazolamide. Subnormal visual acuity, narrowing of visual fields, or both were present on the initial examination in 10 patients; 2 of them, who presented with loss of vision, have permanent visual impairment. Four additional patients presented a transient, mild impairment of visual acuity during treatment. Our study confirms the wide clinical spectrum and the difficulties encountered in diagnosis of idiopathic intracranial hypertension. A wide variety of etiologic associations should be investigated to provide definitive therapy. Loss of visual function is the only serious complication.     

Idiopathic intracranial hypertension in female homozygous twins.

The authors report on female homozygous twins with idiopathic intracranial hypertension. At the age of 12 years, both twins simultaneously developed visual disturbances with photophobia. At the age of 19 years, an ophthalmological examination disclosed papilloedema in both their eyes. At the age of 22 years, a lumbar puncture showed raised CSF pressure over (200 mm H2O) in both twins. Their neurological and radiological examinations were extremely similar; both of them had severely impaired visual acuity and impaired visual field, bilateral optic nerve atrophy, intracranial hypertension, an enlarged and partial empty sella turcica, digital markings of the calvalium, and an enlarged frontal subarachnoid space. This is the first case report describing idiopathic intracranial hypertension occurring in homozygous twins.     

Idiopathic intracranial hypertension and anticardiolipin antibodies

The association of idiopathic intracranial hypertension (IIH) or pseudotumour cerebri (PTC) with anticardiolipin antibodies (aCL-Abs) has been only acknowledged recently. However, its true incidence is as yet unknown. In this retrospective study, the co-occurrence of IIH and aCL-Abs was looked for among a relatively large group of patients diagnosed with IIH or PTC in the neuro-ophthalmology clinic during the years of 1992-8. All patients underwent routine blood tests and the presence of activated protein C resistance and protein S and protein C deficiency were recorded. ACL-Abs were determined in all patients. The co-occurrence of IIH and aCL-Abs was found in three out of 37 patients (8.1%), which is higher than the incidence of aCL-Abs in the general population but considerably lower than that reported in two previously published studies. The aCL-Ab positive patients in our series were significantly older and thinner than those in whom antibodies were undetected. In conclusion, it seems that patients with this association should be considered as a unique subgroup of IIH.     

Idiopathic intracranial hypertension after ofloxacin treatment

We report the occurrence of idiopathic intracranial hypertension in a patient treated with ofloxacin, a fluoroquinolone antimicrobial agent, for 16 months. The withdrawal of ofloxacin and acetazolamide therapy were followed by a complete recovery of visual function.     

Idiopathic intracranial hypertension: risk of recurrences

Long-term prognosis and visual outcome of 54 patients with idiopathic intracranial hypertension (IIH) was studied. Mean observation period was 6.2 years; 33 patients had two or more recurrences. Visual acuity was preserved in all patients without recurrence and in 86% of patients with recurrences. Recurrences did not occur while patients were maintained on acetazolamide. No statistical difference was found between IIH patients who had only one event, compared to the recurrent group.     

Idiopathic intracranial hypertension (Pseudotumor cerebri)

Idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, is a disorder of elevated intracranial pressure of unknown cause. Patients present with daily headache, pulse-synchronous tinnitus, transient visual obscurations, papilledema with its associated visual loss, and diplopia from sixth nerve paresis. Many disease associations have been alleged, but few besides obesity, hypervitaminosis A and related compounds, steroid withdrawal, and female gender have been proven. Although absorption of cerebrospinal fluid (CSF) occurs through arachnoid granulations and extracranial lymphatics, outflow resistance is increased in IIH; therefore, intracranial pressure must increase for CSF to be absorbed. The mainstays of medical treatment are a reduced-sodium weight-reduction program and acetazolamide. If patients fail medical therapy, surgical procedures, most commonly optic nerve sheath fenestration and CSF shunting, are employed. The main morbidity of IIH is visual loss. This is present in most patients and can usually be reversed if recognized early in the course of the disease and treated. Idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, is a disorder of elevated intracranial pressure of unknown cause. Patients present with daily headache, pulse-synchronous tinnitus, transient visual obscurations, papilledema with its associated visual loss, and diplopia from sixth nerve paresis. Many disease associations have been alleged, but few besides obesity, hypervitaminosis A and related compounds, steroid withdrawal, and female gender have been proven. Although absorption of cerebrospinal fluid (CSF) occurs through arachnoid granulations and extracranial lymphatics, outflow resistance is increased in IIH; therefore, intracranial pressure must increase for CSF to be absorbed. The mainstays of medical treatment are a reduced-sodium weight-reduction program and acetazolamide. If patients fail medical therapy, surgical procedures, most commonly optic nerve sheath fenestration and CSF shunting, are employed. The main morbidity of IIH is visual loss. This is present in most patients and can usually be reversed if recognized early in the course of the disease and treated.     

Idiopathic intracranial hypertension in the pediatric population

The aim of this study was to determine the features of pseudotumor cerebri or idiopathic intracranial hypertension in prepubertal and pubertal children. We retrospectively reviewed patient charts of those 16 years and younger, diagnosed with pseudotumor cerebri/idiopathic intracranial hypertension. Our study group consisted of 27 patients; the mean age was 10.9 years, and there was a male-to-female ratio of 13 to 14. In the prepubertal group (n = 13), the male-to-female ratio was 8 to 5; in the pubertal group, (n = 14), the ratio was 5 to 9. Overweight or obesity was found in 16 (59%) patients. Outcome was favorable except for one who remained symptomatic. Pseudotumor cerebri/idiopathic intracranial hypertension in children is rare. Its characteristics differ from adults. We found the prepubertal group to be a distinct group since pseudotumor cerebri/idiopathic intracranial hypertension did not occur predominantly in females and was not associated with obesity.