A Practical Approach To, Diagnosis, Assessment and Management Of

REVIEW A practical approach to, diagnosis, Pract Neurol: first published as 10.1136/practneurol-2014-000821 on 8 May 2014. Downloaded from assessment and management of idiopathic intracranial hypertension Susan P Mollan,1 Keira A Markey,2 James D Benzimra,1 Andrew Jacks,1 Tim D Matthews,1 Michael A Burdon,1 Alex J Sinclair2,3 1Birmingham Neuro- ABSTRACT term to encompass primary raised intra- Ophthalmology Unit, Adult patients who present with papilloedema cranial pressure where there is no identi- Ophthalmology Department, — — University Hospitals Birmingham and symptoms of raised intracranial pressure fiable cause which we term IIH and 3 NHS Trust, Queen Elizabeth need urgent multidisciplinary assessment secondary causes of raised pressure. Hospital Birmingham, including neuroimaging, to exclude life- The diagnostic criteria of IIH are well Birmingham, UK 2 threatening causes. Where there is no apparent known and have evolved since Dandy’s Neurotrauma and 4 Neurodegeneration, School of underlying cause for the raised intracranial initial description in 1937 ; they include Clinical and Experimental pressure, patients are considered to have a CSF opening pressure of ≥25 cm H2O Medicine, College of Medical idiopathic intracranial hypertension (IIH). The (box 1).3 However, these criteria recom- and Dental Sciences, The incidence of IIH is increasing in line with the mend imaging only to exclude a venous Medical School, The University of Birmingham, Birmingham, UK global epidemic of obesity. There are sinus thrombosis in patients without the 3Department of Neurology, controversial issues in its diagnosis and typical IIH phenotype (obesity and University Hospital Birmingham management. This paper gives a practical female sex). We feel, however, that it is NHS Trust, Queen Elizabeth Hospital Birmingham, approach to assessing patients with essential to exclude venous sinus throm- Birmingham, UK papilloedema, its investigation and the bosis (using MRI or CT with venography) subsequent management of patients with IIH. in all patients presenting with pseudotu- Correspondence to mour cerebri, since being female and Dr Alex J Sinclair, Neurotrauma and obese does not preclude the diagnosis of Neurodegeneration, School of INTRODUCTION venous sinus thrombosis. The diagnosis Clinical and Experimental Idiopathic intracranial hypertension (IIH) can be difficult and the consequences of http://pn.bmj.com/ Medicine, College of Medical is becoming increasingly prevalent in line error can lead either to the neglect of a and Dental Sciences, The 1 Medical School, The University with the global epidemic of obesity. In serious treatable cause of raised intracra- of Birmingham, Wolfson Drive, the UK, 22.7% of people are obese nial pressure, blindness or inappropriate Edgbaston, Birmingham, (Body Mass Index >30 kg/m2), while treatment of patients who do not have B15 2TT, UK; obesity throughout the world has [email protected] IIH. Although there is insufficient litera- doubled since 1980. Clinicians’ attitudes ture to generate an evidence-based man- on September 29, 2021 by guest. Protected copyright. to IIH vary: in our experience, only a agement strategy for IIH,5 experienced minority of patients are at high risk of clinicians can manage it well. rapid visual loss.2 The previously quoted figure of 25% developing severe perman- ent visual loss is probably an overesti- AN APPROACH TO PAPILLOEDEMA mate.2 The reality for patients is that it is Patients generally present to the emer- a chronic condition characterised by sig- gency department after an optometrist or nificantly disabling headaches and psy- family doctor detects papilloedema. They chological morbidity. may or may not have other symptoms. The nomenclature for IIH has changed Because papilloedema indicates poten- over the years: previous names being tially serious underlying disease, the serous meningitis, pseudotumour cerebri purpose of the visit is to recognise and To cite: Mollan SP, or benign intracranial hypertension. The confirm the presence of papilloedema and Markey KA, Benzimra JD, latter became inappropriate with aware- arrange appropriate onward investigation. et al. Pract Neurol Published Online First: [please include ness that this is not a benign condition, An important issue is that, in the UK, the Day Month Year] given the risk of visual loss and disabling most junior and inexperienced doctor doi:10.1136/practneurol- chronic headaches. Pseudotumour cerebri often assesses the patient first to confirm 2014-000821 is becoming increasingly popular as a the clinical finding of papilloedema. Once Mollan SP, et al. Pract Neurol 2014;0:1–11. doi:10.1136/practneurol-2014-000821 1 REVIEW CLUES FROM THE HISTORY Pract Neurol: first published as 10.1136/practneurol-2014-000821 on 8 May 2014. Downloaded from Box 1 Diagnostic criteria for adult IIH* Headaches are common and can be highly variable (see later). They may be of new onset or more ▸ Papilloedema. chronic, particularly in those with previous migraine. ▸ Normal neurological examination except for cranial Visual symptoms include blurred or double vision. nerve abnormalities. Patients can describe transient loss of vision and/or ▸ Neuroimaging: Normal brain parenchyma without ‘greying out’ of vision: so-called ‘transient visual hydrocephalus, mass or structural lesion and no obscurations’. They usually relate to postural changes; abnormal meningeal enhancement or venous sinus and are usually brief, typically only seconds. Patients thrombosis on MRI and MR venography; if MRI is may report horizontal diplopia from a false-localising unavailable or contraindicated, contrast-enhanced CT abducens nerve palsy. There may be pulsatile tinnitus may be used. —a rhythmic ‘whooshing’ sound heard in either or ▸ Normal CSF composition. both ears synchronous with the patient’s heartbeat, ▸ Elevated CSF opening pressure (≥25 cmH2O) in a and often present only on lying down. Many patients properly performed lumbar puncture. do not volunteer this symptom unless directly asked. ▸ A diagnosis of IIH is definite in patients fulfilling A–E; the diagnosis is probable if A–D are met but the CSF CLUES FROM THE EXAMINATION pressure is lower than specified. Clinicians should examine visual function (table 1) *Adapted from the 2013 revised diagnostic criteria for and extraocular movements in all cases. IIH.3 Distinguishing pseudopapilloedema from papilloedema This requires clinical experience. Pseudopapilloedema may be due to congenitally anomalous discs, optic an ophthalmologist (of any grade) labels the patient as nerve head drusen or a combination of the two. having papilloedema, this is rarely questioned further, Congenitally anomalous discs are small nerves that lack and the pathway of investigations moves forward. a physiological cup. Optic nerve head drusen are Recognising papilloedema is usually straightforward globular hyaline bodies, which may be calcified. They (figure 1) but occasionally it can be very difficult to dis- are often seen incidentally during routine eye tests and tinguish papilloedema from congenitally anomalous up to 2% of the general Caucasian population may discs and pseudopapilloedema (figure 2). Where there have them. Sometimes, they are obvious (figure 4). is diagnostic difficulty, it is best to seek early assessment However, they are difficult to see when buried, the by neuro-ophthalmology, or a senior ophthalmologist only clue being increased retinal vessel branching at the with experience in differentiating swollen from appar- optic nerve head (figure 5). Ophthalmic ultrasound ently swollen optic discs. This avoids invasive investiga- scanning (figure 6) can confirm their presence. Very http://pn.bmj.com/ tions in the normal patient. occasionally when there is still diagnostic doubt such as, ‘are these congenitally anolamous discs swollen?’ Case 1—Are you sure it is papilloedema? fundus fluorescein angiography can help to determine A 23-year-old right-handed woman was referred by if there is disc leakage (figure 7). her optician to the emergency unit with longstanding It can be extremely difficult to distinguish pseudopa- headaches and swollen optic discs. Since the age of pilloedema from papilloedema and, where there is on September 29, 2021 by guest. Protected copyright. 12 years, she had experienced frequent headaches and uncertainty, clinicians must keep an open mind. recently had developed continuous tinnitus. She had Inappropriately labelling pseudopapilloedema as IIH no previous medical or ocular history and currently can have significant negative implications, and we have took no medication. On examination, her Body Mass seen these cases complicated by morbidity from surgi- Index was 36 kg/m2. Her visual acuities were 6/6 bilat- cal shunting and the side effects of acetazolamide. erally, aided with a small hypermetropic correction (right eye+1.75 diopters sphere and left eye+1.25 INVESTIGATION diopters sphere). She was already dilated after seeing Having identified papilloedema, it is essential to the optician and the emergency doctor noted nasal disc record blood pressure to exclude malignant hyperten- margin blurring. She underwent normal neuro-imaging sion. Patients then need urgent neuroimaging: this has (MRI and MR venogram). Her lumbar puncture two purposes, to identify any space-occupying lesion opening pressure was 26 cm CSF with normal constitu- and to exclude a venous sinus thrombosis. The pre- ents. She was discharged on oral acetazolamide ferred imaging method is an MR scan of the head and 250 mg

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