Idiopathic Intracranial Hypertension Treatment Trial

Summary

Idiopathic intracranial hypertension (IIH), also called pseudotumor cerebri, is a disorder of elevated intracranial pressure of unknown cause \[Corbett, et al., 1982; Wall, et al., 1991\]. Its incidence is 22.5 new cases each year per 100,000 overweight women of childbearing age, and is rising \[Garrett, et al., 2004\] in parallel with the obesity epidemic. It affects about 100,000 Americans. Most patients suffer debilitating headaches. Because of pressure on the optic nerve (papilledema), 86% have some degree of permanent visual loss and 10% develop severe visual loss \[Wall, et al., 1991\]. Interventions to prevent loss of sight, all with unproven efficacy, include diet, diuretics such as acetazolamide, repeated spinal taps, optic nerve sheath fenestration surgery, and cerebrospinal fluid (CSF) shunting procedures. The purported goal of these therapies is to lower intracranial pressure; however, it is unclear which treatments work and by what mechanism. None of these strategies has been verified by properly designed clinical trials. Thus, there is confusion, uncertainty, and weak scientific rationales to guide treatment decisions. This trial will study subjects who have mild visual loss from IIH to (1) establish convincing, evidence-based treatment strategies for IIH to restore and protect vision, (2) follow subjects up to 4 years to observe the long-term treatment outcomes and (3) determine the cause of IIH. To meet those aims, the trial will be divided into a 12-month intervention phase and a 3-year observational phase. Subjects are not required to complete the observational phase of the study, but will be asked to do so and consented for the observational phase of the study at the conclusion of the intervention phase (12 months).

Conditions

• Idiopathic Intracranial Hypertension

Interventions

DRUG

Acetazolamide

Subjects will begin with four 250 mg tablets daily. Tablets will be divided among two doses, taken with meals. Beginning on day 7, subjects will increase the dose by 1 pill every week until 16 tablets daily is reached (4 grams acetazolamide or placebo) or side effects prohibit increasing the dosage further. Thus, subjects who are able to tolerate the study medication will reach the maximum dose by day 84.

DRUG

Placebo

Subjects will begin with four tablets daily. Tablets will be divided among two doses, taken with meals. Beginning on day 7, subjects will increase the dose by 1 pill every week until 16 tablets daily is reached (4 grams acetazolamide or placebo) or side effects prohibit increasing the dosage further. Thus, subjects who are able to tolerate the study medication will reach the maximum dose by day 84.

BEHAVIORAL

Formal weight loss counselling program

Teleconference, web-based from central location, using site visits and subject self-assessment tools

Sponsors & Collaborators

• National Eye Institute (NEI)

  collaborator NIH

• University of Rochester

  collaborator OTHER

• University of Iowa

  collaborator OTHER

• University of California, Davis

  collaborator OTHER

• St. Luke's-Roosevelt Hospital Center

  lead OTHER

Principal Investigators

• Michael Wall, MD · University of Iowa

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

60 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2010-01-31

Primary Completion

2013-06-30

Completion

2014-01-31

Countries

• United States
• Canada

Study Locations