Condition category
Nervous System Diseases
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status

Plain English Summary

Background and study aims
Idiopathic intracranial hypertension (IIH) is a condition with an unknown cause that is associated with raised pressure in the brain and can cause disabling daily headaches and loss of vision, which can be permanent. The raised brain pressure squashes the nerves supplying the eye (also known as papilloedema) and this can affect vision. Over 90% of patients with IIH are overweight and weight loss is the most effective treatment. Other treatments for IIH have very little current evidence to support their use. This study aims to compare two methods of weight loss, bariatric surgery and the most effective dietary programme commonly available, Weight Watchers, to see which offers the most effective long-term treatment for IIH.

Who can participate?
This study will enrol women aged between 18 and 55 with IIH and body mass index (BMI) >35kg/m2 from the Queen Elizabeth Hospital Birmingham (UK). Women who do not have IIH will also be enrolled for comparison.

What does the study involve?
Participants with IIH will be randomly allocated to either attend their local Weight Watchers group or undergo bariatric surgery. The latter will be referred to the Birmingham Heartlands Hospital to receive a gastric band, which is the safest bariatric surgery option. A third control group of 20 women with similar characteristics but who do not have IIH will provide a comparison but will not participate further in the study. Participants with IIH will then be followed up for five years, with the most important measurement being their brain pressure after one year of being in the study. Participants with IIH and the 20 obese controls will also be asked to give samples of urine, blood and cerebrospinal fluid, and asked to participate in sub-studies which will look at the relationship between IIH and other illnesses connected with obesity from which they may suffer.

What are the possible benefits and risks of participating?
The benefit is that both groups of participants will be allocated to a treatment which is proven to bring about weight loss. The main risk is to patients in the bariatric surgery arm: gastric banding, although safe, is a major operation, and careful follow-up is required. Laparoscopic gastric banding has a death rate of less than 0.1% and major complications are extremely rare. Apart from the risks of bariatric surgery for those participants in the surgery arm, the main risks are those of side effects involved in the lumbar punctures, and the discomfort of the lumbar punctures and of the blood samples being taken.

Where is the study run from?
The study is being run from University of Birmingham Clinical Trials Unit (BCTU), UK.

Who is funding the study?
National Institute for Health Research (NIHR) (UK).

Who is the main contact?
Mr Ryan Ottridge

Trial website

Contact information



Primary contact

Dr Alexandra Sinclair


Contact details

IBR West Wing
School of Clinical and Experimental Medicine
University of Birmingham
B15 2TT
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

A randomised controlled trial of bariatric surgery versus a community weight loss programme for the sustained treatment of Idiopathic Intracranial Hypertension: the IIH:WT Trial



Study hypothesis

The trial will evaluate the effectiveness of two methods of weight loss in the treatment of IIH: gastric banding vs. dietetic intervention.

Ethics approval

Black Country REC, 28/02/2014, ref: 14/WM/0011

Study design

Randomised controlled parallel arm trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Idiopathic Intracranial Hypertension (IIH) - neurology, neuro-ophthalmology.


Patients are randomised 1:1 to bariatric surgery or dietetic intervention

1. 30 participants randomised to the bariatric surgery arm of the trial will be referred to the surgery pathway to receive laparoscopic gastric banding.
2. 30 participants randomised to the dietetic arm will be given vouchers to except them from paying for 12 months of Weight Watchers.

There will also be a 20-participant matched obese control group who will undergo the baseline visit, and a 5-patient magnetic resonance imaging (MRI) test scan group to validate the novel scans being used.

Intervention type



Not Applicable

Drug names

Primary outcome measures

Change in Intracranial Pressure (ICP) between baseline and 12 months measured by lumbar puncture at baseline and 12 months. ICP will be recorded to the nearest whole number in cmH2O

Secondary outcome measures

Secondary Outcome Measures:
1. Change in ICP between baseline and 24 and 60 months measured by lumbar puncture. ICP will be recorded to the nearest whole number in cmH2O
2. Change in reported IIH symptoms from 0 to 12 months (and at 3, 6, 24 and 60 months) measured by clinician-completed CRFs and participant-completed questionnaire
3. Change in visual function from 0 to 12 months (and at 24 and 60 months). This will be measured by the LogMAR (log of the minimum angle of resolution) chart to assess visual acuity, automated perimetry (Humphrey 24-2 central threshold) to measure the visual field mean deviation, a Pelli-Robson chart to evaluate contrast sensitivity and an Ishihara book to assess colour vision.
4. Change in papilloedema from 0 to 12 months (and at 24 and 60 months). This will be measured using spectral optical coherence tomography. Papilloedema will be further graded by blinded assessment of, and assignation of Frisen score to, fundus photographs.
5. Change in headache-associated disability from 0 to 12 months (and at 24 and 60 months) measured by participant-completed questionnaire including analgesic use, Headache Index, and Headache Impact Test-6
6. Change in anthropological measures (e.g. waist, hip, fat mass) from 0 to 12 months (and at 24 and 60 months)
7. Change in quality of life (participant reported) from 0 to 12 months (and at 24 and 60 months) measured by participant-reported questionnaire (EQ-5D-5L and ICECAP-A questionnaires)
8. Difference in number of referrals to Cerebrospinal Fluid (CSF) shunting procedures and optic nerve sheath fenestration between treatment arms at 0 to 12 months (and at 24 and 60 months). This will be measured on clinical follow-up CRFs.
9. Health economics including cost-effectiveness at 12, 24 and 60 months measured by participant-reported health resource usage questionnaire and EQ-5D-5L and ICECAP-A questionnaires

Sub-study Exploratory Outcome Measures:
1. Change in apnoea-hypopnoea index from 0 to 12 months
2. Change in markers of peripheral neuropathy and metabolic syndrome from 0 to 12 months
3. Change in Magnetic Resonance (MR) imaging (including venous stenoses) from 0 to 12 months
4. Change in cognitive function from 0 to 12 months
5. Change in biomarkers from 0 to 12 (and 24 and 60) months
6. Comparison between IIH patients and the matched control group at baseline with regards to apnoea-hypopnoea index, peripheral neuropathy and metabolic syndrome, MR imaging, cognitive function, and biomarkers
7. Change in MR imaging over a double baseline period of healthy controls

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. Female IIH patients aged between 18 and 55 years, diagnosed according to the modified Dandy criteria who have chronic (> 6 months duration), active disease (visual impairment, papilloedema, significantly raised ICP > 25 cmH2O) and normal brain imaging (magnetic resonance imaging and venography as noted at diagnosis)
2. Body mass index (BMI) >35 kg/m2
3. Tried other appropriate non-surgical treatments to lose weight but have not been able to achieve or maintain adequate, clinically beneficial weight loss for at least 6 months
4. Able to give informed consent

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Age less than 18 or older than 55 years
2. Pregnant or planning to conceive during the first 18 months of the trial
3. Significant co-morbidity, endocrinopathy or the use of hormone-manipulating medication
4. Undergone optic nerve sheath fenestration
5. Definite indication for or contraindication against surgery or dieting
6. Have a specific medical or psychiatric contraindication for surgery, including drug misuse, eating disorder or major depression (suicidal ideation, drug overdose or psychological admission in last 12 months)

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

IBR West Wing, School of Clinical and Experimental Medicine
B15 2TT
United Kingdom

Sponsor information


University of Birmingham (UK)

Sponsor details

c/o Mr Sean Jennings
Research Governance Officer
Research Support Group
Room 119 Aston Webb Building
Block B
B15 2TT
United Kingdom

Sponsor type




Funder type


Funder name

National Institute for Health Research (NIHR) (UK) - Research Fellowship, NIHR-CS-011-028

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes