The presenting visual symptoms of optic chiasmal disease

Recognising optic chiasmal disease early is important in order to avoid irreversible visual loss and the potential risk of mortality for patients. Yet, there is frequently a delay in the initial diagnosis. Whilst the signs of optic chiasmal disease, particularly the perimetric findings, are well documented in the recent literature, the symptoms have been less well reported. Whilst some patients with optic chiasmal disease will be asymptomatic, many will complain of visual symptoms including symptomatic field defects, problems with central vision, difficulty with near tasks, binocular visual disturbances, colour vision disturbances, photophobia, phosphenes, glare, and rarely, oscillopsia and visual hallucinations. Others may have headache or the severe and sudden visual symptoms associated with pituitary apoplexy. The visual symptoms may be vague or non-specific, even when there are significant bitemporal visual field defects. We aim in this review to describe the presenting visual symptoms of optic chiasmal disease, and to illustrate these with selected qualitative descriptions from the literature. Our hope is that this will aid clinicians in eliciting a careful history of the sometimes subtle symptoms that may be present.

Paraneoplastic Syndromes in Neuro-Ophthalmology

Paraneoplastic neurological syndromes (PNS) occur in about 1 in 300 cases of cancer. The usual mechanism is that an antigen on the cancer sets off an immune response that then cross-reacts with a nervous system antigen. The presentation is usually with a subacute progressive neurological disorder. The management of these conditions is usually of both the underlying tumor and immunomodulation to suppress the autoimmune response. There are a number of these conditions that can present to the Neuro-Ophthalmology clinic, either as a discrete condition affecting vision or eye movements or as part of a more widespread neurological disorder. This article will discuss these conditions, their management and prognosis.

Association of Amount of Weight Lost After Bariatric Surgery With Intracranial Pressure in Women With Idiopathic Intracranial Hypertension

BACKGROUND AND OBJECTIVES

The idiopathic intracranial hypertension randomized controlled weight trial (IIH:WT) established that weight loss through bariatric surgery significantly reduced intracranial pressure when compared with a community weight management intervention. This substudy aimed to evaluate the amount of weight loss required to reduce intracranial pressure and to explore the effect of different bariatric surgical approaches.

METHODS

IIH:WT was a multicenter randomized controlled trial. Adult women with active idiopathic intracranial hypertension and a body mass index ≥35 kg/m2 were randomized to bariatric surgery or a community weight management intervention (1:1). This per-protocol analysis evaluated the relationship between intracranial pressure, weight loss, and the weight loss methods. A linear hierarchical regression model was used to fit the trial outcomes, adjusted for time, treatment arm, and weight.

RESULTS

Sixty-six women were included, of whom 23 had received bariatric surgery by 12 months; the mean age was 31 (SD 8.7) years in the bariatric surgery group and 33.2 (SD 7.4) years in the dietary group. Baseline weight and intracranial pressure were similar in both groups with a mean weight of 119.5 (SD 24.1) and 117.9 (SD 19.5) kg and mean lumbar puncture opening pressure of 34.4 (SD 6.3) and 34.9 (SD 5.3) cmCSF in the bariatric surgery and dietary groups, respectively. Weight loss was significantly associated with reduction in intracranial pressure (R2 = 0.4734, p ≤ 0.0001). Twenty-four percentage of weight loss (weight loss of 13.3 kg [SD 1.76]) was associated with disease remission (intracranial pressure [ICP] ≤ 25 cmCSF). Roux-en-Y gastric bypass achieved greater, more rapid, and sustained ICP reduction compared with other methods.

DISCUSSION

The greater the weight loss, the greater the reduction in ICP was documented. Twenty four percentage of weight loss was associated with disease remission. Such magnitude of weight loss was unlikely to be achieved without bariatric surgery, and hence, consideration of referral to a bariatric surgery program early for those with active idiopathic intracranial hypertension may be appropriate.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02124486; ISRCTN registry number ISRCTN40152829; doi.org/10.1186/ISRCTN40152829.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that weight loss after bariatric surgery results in reduction in intracranial pressure in adult women with idiopathic intracranial hypertension. This study is Class II because of the use of a per-protocol analysis.

Neuro-Ophthalmic Complications of Vestibular Schwannoma Resection: Current Perspectives

Vestibular schwannomas (VSs), also called acoustic neuromas, are benign intracranial neoplasms of the vestibulocochlear (VIII) cranial nerve. Management options include “wait-and-scan,” stereotactic radiosurgery and surgical resection. Due to the proximity of the VIII nerve to the facial (VII) nerve in the cerebello-pontine angle, the VII nerve is particularly vulnerable to the effects of surgical resection. This can result in poor eye closure, lagophthalmos and resultant corneal exposure post VS resection. Additionally, compression from the tumor or resection can cause trigeminal (V) nerve damage and a desensate cornea. The combination of an exposed and desensate cornea puts the eye at risk of serious ocular complications including persistent epithelial defects, corneal ulceration, corneal vascularization, corneal melting and potential perforation. The abducens (VI) nerve can be affected by a large intracranial VS causing raised intracranial pressure (a false localizing sign) or as a result of damage to the VI nerve at the time of resection. Other types of neurogenic strabismus are rare and typically transient. Contralaterally beating nystagmus as a consequence of vestibular dysfunction is common post-operatively. This generally settles to pre-operative levels as central compensation occurs. Ipsilaterally beating nystagmus post-operatively should prompt investigation for post-operative cerebrovascular complications. Papilledema (and subsequent optic atrophy) can occur as a result of a large VS causing raised intracranial pressure. Where papilledema follows surgical resection of a VS, it can indicate that cerebral venous sinus thrombosis has occurred. Poor visual function following VS resection can result as a combination of all these potential complications and is more likely with larger tumors.

Update on Optic Neuritis: An International View

Previously, optic neuritis was thought to be typical, i.e. idiopathic or multiple sclerosis (MS) related, associated with a good visual prognosis, or atypical, i.e. not associated with MS and requiring corticosteroids or plasma exchange for vision to recover. More recently, the importance of optic neuritis in neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein (MOG) antibody disease has become more appreciated. The results of the Optic Neuritis Treatment Trial (ONTT) has influenced how optic neuritis is treated around the world. For this review we surveyed the international literature on optic neuritis in adults. Our aims were first to find the reported incidence of optic neuritis in different countries and to ascertain what percentage of cases were seropositive for anti-aquaporin 4 and anti-MOG antibodies, and second, to document the presenting features, treatment, and outcomes from a first episode of the different types of optic neuritis from these countries, and to compare the results with the outcomes of the ONTT cohort. From these data we have sought to highlight where ambiguities currently lie in how to manage optic neuritis and have made recommendations as to how future treatment trials in optic neuritis should be carried out in the current antibody testing era.

Effectiveness of Bariatric Surgery vs Community Weight Management Intervention for the Treatment of Idiopathic Intracranial Hypertension: A Randomized Clinical Trial

Question

Is bariatric surgery superior to a community weight management intervention in sustaining the weight loss necessary to achieve sustained remission among patients with idiopathic intracranial hypertension?

Findings

In this randomized clinical trial of 66 women with idiopathic intracranial hypertension and a body mass index of 35 or higher, bariatric surgery was superior to a community weight management intervention in decreasing intracranial pressure, with continued improvement at 2 years.

Meaning

The study’s findings indicate that, among women with idiopathic intracranial hypertension and a body mass index of 35 or higher, bariatric surgery is an effective treatment to reduce intracranial pressure and for sustained disease remission.

Importance

Idiopathic intracranial hypertension (IIH) causes headaches, vision loss, and reduced quality of life. Sustained weight loss among patients with IIH is necessary to modify the disease and prevent relapse.

Objective

To compare the effectiveness of bariatric surgery with that of a community weight management (CWM) intervention for the treatment of patients with active IIH.

Design, Setting, and Participants

This 5-year randomized clinical trial (Idiopathic Intracranial Hypertension Weight Trial) enrolled women with active IIH and a body mass index (calculated as weight in kilograms divided by height in meters squared) of 35 or higher at 5 National Health Service hospitals in the UK between March 1, 2014, and May 25, 2017. Of 74 women assessed for eligibility, 6 did not meet study criteria and 2 declined to participate; 66 women were randomized. Data were analyzed from November 1, 2018, to May 14, 2020.

Interventions

Bariatric surgery (n = 33) or CWM intervention (Weight Watchers) (n = 33).

Main Outcomes and Measures

The primary outcome was change in intracranial pressure measured by lumbar puncture opening pressure at 12 months, as assessed in an intention-to-treat analysis. Secondary outcomes included lumbar puncture opening pressure at 24 months as well as visual acuity, contrast sensitivity, perimetric mean deviation, and quality of life (measured by the 36-item Short Form Health Survey) at 12 and 24 months. Because the difference in continuous outcomes between groups is presented, the null effect was at 0.

Results

Of the 66 female participants (mean [SD] age, 32.0 [7.8] years), 64 (97.0%) remained in the clinical trial at 12 months and 54 women (81.8%) were included in the primary outcome analysis. Intracranial pressure was significantly lower in the bariatric surgery arm at 12 months (adjusted mean [SE] difference, −6.0 [1.8] cm cerebrospinal fluid [CSF]; 95% CI, −9.5 to −2.4 cm CSF; P = .001) and at 24 months (adjusted mean [SE] difference, −8.2 [2.0] cm CSF; 95% CI, −12.2 to −4.2 cm CSF; P < .001) compared with the CWM arm. In the per protocol analysis, intracranial pressure was significantly lower in the bariatric surgery arm at 12 months (adjusted mean [SE] difference, −7.2 [1.8] cm CSF; 95% CI, −10.6 to −3.7 cm CSF; P < .001) and at 24 months (adjusted mean [SE] difference, −8.7 [2.0] cm CSF; 95% CI, −12.7 to −4.8 cm CSF; P < .001). Weight was significantly lower in the bariatric surgery arm at 12 months (adjusted mean [SE] difference, −21.4 [5.4] kg; 95% CI, −32.1 to −10.7 kg; P < .001) and at 24 months (adjusted mean [SE] difference, −26.6 [5.6] kg; 95% CI, −37.5 to −15.7 kg; P < .001). Quality of life was significantly improved at 12 months (adjusted mean [SE] difference, 7.3 [3.6]; 95% CI, 0.2-14.4; P = .04) and 24 months (adjusted mean [SE] difference, 10.4 [3.8]; 95% CI, 3.0-17.9; P = .006) in the bariatric surgery arm.

Conclusions and Relevance

In this randomized clinical trial, bariatric surgery was superior to a CWM intervention in lowering intracranial pressure. The continued improvement over the course of 2 years shows the impact of this intervention with regard to sustained disease remission.

Trial Registration

ClinicalTrials.gov Identifier: NCT02124486

Is a virtual clinic model a safe and effective way for assessing patients referred with suspiciously blurred optic discs? The blurred disc clinic

BACKGROUND

There are increasing numbers of referrals to ophthalmology departments due to blurred optic disc margins. In light of this and the COVID-19 pandemic we aimed to assess whether these patients could be safely assessed without direct contact between the clinician and patient.

METHODS

We retrospectively reviewed the records of consecutive patients seen in our 'blurred disc clinic' between August 2018 and October 2019. We then presented anonymous information from their referral letter, their visual fields and optic nerve images to two consultant neuro-ophthalmologists blinded to the outcome of the face-to-face consultation. In the simulated virtual clinic, the two consultants were asked to choose an outcome for each patient from discharge, investigate or bring in for a face-to-face assessment.

RESULTS

Out of 133 patients seen in the blurred disc clinic, six (4.5%) were found to have papilloedema. All six were identified by both neuro-ophthalmologists as needing a face-to-face clinic consultation from the simulated virtual clinic. One hundred and twenty (90%) patients were discharged from the face-to-face clinic at the first consultation. The two neuro-ophthalmologists chose to discharge 114 (95%) and 99 (83%) of these respectively from the simulated virtual clinic. The virtual clinic would have potentially missed serious pathology in only one patient who had normal optic discs but reported diplopia at the previous face-to-face consultation.

CONCLUSIONS

A virtual clinic model is an effective way of screening for papilloedema in patients referred to the eye clinic with suspicious optic discs. Unrelated or incidental pathology may be missed in a virtual clinic.

Neurofilament results for the phase II neuroprotection study of phenytoin in optic neuritis

BACKGROUND

A randomized trial of phenytoin in acute optic neuritis (ON) demonstrated a 30% reduction in retinal nerve fiber layer (RNFL) loss with phenytoin versus placebo. Here we present the corresponding serum neurofilament analyses.

METHODS

Eighty-six acute ON cases were randomized to receive phenytoin (4-6 mg/kg/day) or placebo for 3 months, and followed up for 6 months. Serum was collected at baseline, 3 and 6 months for analysis of neurofilament heavy chain (NfH) and neurofilament light chain (NfL).

RESULTS

Sixty-four patients had blood sampling. Of these, 58 and 56 were available at 3 months, and 55 and 54 were available at 6 months for NfH and NfL, respectively. There was no significant correlation between serum NfH and NfL at the time points tested. For NfH, the difference in mean placebo - phenytoin was -44 pg/ml at 3 months (P = 0.019) and -27 pg/ml at 6 months (P = 0.234). For NfL, the difference was 1.4 pg/ml at 3 months (P = 0.726) and -1.6 pg/ml at 6 months (P = 0.766).

CONCLUSIONS

At 3 months, there was a reduction in NfH, but not NFL, in the phenytoin versus placebo group, while differences at 6 months were not statistically significant. This suggests a potential neuroprotective role for phenytoin in acute ON, with the lower NfH at 3 months, when levels secondary to degeneration of the anterior visual pathway are still elevated, but not at 6 months, when levels have normalized.

Optic nerve sheath fenestration via a supero-medial eyelid skin crease approach for the treatment of idiopathic intracranial hypertension in a UK population

BACKGROUND/AIMS

Optic nerve sheath fenestration (ONSF) is a surgical intervention in the management of idiopathic intracranial hypertension (IIH) infrequently performed in the United Kingdom. Numerous surgical approaches have been described, including medial transconjunctival, lateral and endoscopic. We describe our outcomes and complications from ONSF via a supero-medial eyelid skin crease incision in patients with IIH.

METHODS

We performed a retrospective review of consecutive patients undergoing ONSF for IIH between January 2011 and December 2017 by a single surgeon.

RESULTS

Thirty patients were included in the analysis with a median follow-up of 14.5 months. Bilateral ONSFs were undertaken in 27 (90%). The data from one eye per patient were analysed. The mean kinetic perimetry score in mean radial degrees of the I4e isopter improved from 27.3° to 35.7°, p = 0.04. After removing cases with optic atrophy, the median modified Frisén grade of papilloedema improved from 2.5 to 1.0, p = 0.007. A total of 5/30 (17%) patients had complications: two (7%) had recurrence/late failure (one managed medically and one with cerebrospinal fluid [CSF] diversion surgery), one had transient cotton wool spots post-operatively, one had transient retinal haemorrhages and one patient had a transiently oval pupil. No patients had repeat ONSF, but CSF diversion surgery was subsequently carried out in 4/30 (13%) patients.

CONCLUSIONS

ONSF via a supero-medial eyelid skin crease approach is effective at improving visual function in patients with IIH. The complication rates are low when compared with CSF diversion surgery and other surgical approaches for ONSF.

The Utility of Fundus Fluorescein Angiography in Neuro-Ophthalmology

While its use is still widespread within the medical retina field, fundus fluorescein angiography (FFA) is increasingly falling out of favour in the investigation of neuro-ophthalmological disease, with the introduction of new technologies, particularly optical coherence tomography. FFA does, however, provide useful diagnostic and prognostic information in many neuro-ophthalmological diseases including papilloedema, pseudo-papilloedema, optic neuropathies and central retinal artery occlusion to name a few. We aim to summarise the main FFA findings in each of these conditions and highlight where FFA is of most use in providing complementary information to other modes of investigation.

Treatment and Outcomes in Nutritional Optic Neuropathy

PURPOSE OF REVIEW

Nutritional optic neuropathy is a potential cause of severe visual loss; however, appropriate and timely management can result in excellent visual outcomes. The purpose of this review is to outline our current understanding of the treatment and outcomes for nutritional optic neuropathy.

RECENT FINDINGS

Current understanding of nutritional optic neuropathy has been greatly aided by some well-reported and investigated epidemics of the condition, most notably the Cuban epidemic optic neuropathy of the early 1990s. More recently, there is an emerging literature surrounding nutritional deficiencies that can occur in patients who have undergone bariatric surgery. There also continues to be a stream of case reports in the literature that add to our understanding. Nutritional optic neuropathy has a great deal of overlap with toxic optic neuropathies and hereditary optic neuropathies and should not be thought of in isolation from these conditions. The mainstay of treatment for nutritional optic neuropathy involves identifying and replacing deficient nutrients as well as identifying and eliminating contributory toxins. It is also important to identify contributory genetic factors and to consider the broader social, economic and societal factors which may contribute.

A Stereotyped Syndrome with Retro-Ocular Pain, Photophobia, and Visual Disturbance Masquerading as Optic Neuritis: Case Series

We describe here a case series of six patients referred to the Neuro-ophthalmology service in Sheffield, UK with possible acute unilateral optic neuritis. Each patient had a triad of unilateral photophobia, ipsilateral retro-ocular pain, and ipsilateral loss of vision. All patients had normal ocular examinations and investigation findings with no objective structural or functional abnormalities identified. Patients were treated by weaning-off regular analgesia and, where appropriate, commencing migraine prophylaxis. In the three patients with complete recovery of pain, there was also complete recovery of vision. We propose that this is a migraine syndrome and that the decreased visual acuity is a functional consequence of the pain and photophobia.

Do Optic Canal Dimensions Measured on CT Influence the Degree of Papilloedema and Visual Dysfunction in Idiopathic Intracranial Hypertension?

A recent study found that increased optic canal area on magnetic resonance imaging was associated with worse papilloedema in idiopathic intracranial hypertension (IIH). We repeated this study using more accurate computerized tomography derived measurements. Optic canal dimensions were measured from 42 IIH patients and 24 controls.  These were compared with papilloedema grade.  There was no correlation between any of the optic canal measurements and papilloedema grade and no significant difference in optic canal measurements between patients and controls. Our results cast doubt on the existing literature regarding the association between optic canal size and the degree of papilloedema in IIH. CT delineates bony anatomy more accurately than MRI and our CT-derived optic canal measurements cast doubt on the existing literature regarding the association between optic canal size and the degree of Papilloedema in IIH.

Idiopathic Acquired Temporal Wedge Visual Field Defects

Our aim is to report 13 unusual cases of acquired, temporal sectoral scotomas. Such stationary "wedge" field defects have been reported previously in cases of presumed congenital nasal hypoplasia of the optic disc and as a complication of vitreoretinal surgery. To our knowledge, the literature provides no reports of similar defects occurring spontaneously. This is a descriptive clinical case series of 13 patients presenting with sub-acute monocular temporal visual field loss. All were clinically assessed and investigated with Goldmann perimetry, automated Humphrey visual fields, retinal optical coherence tomography, orbital ultrasound, and standard and multi-focal electroretinography. Cases were followed with serial perimetry for a mean of 3.9 years (range: 6 months to 10 years). Goldmann and Humphrey perimetry both demonstrated "wedge"-shaped defects extending temporally from an apex contiguous with, or lateral to, the blind spot. There was no evidence of optic disc drusen, glaucoma, disc hypoplasia, or focal retinitis. Sectoral optic disc swelling was not present in any patient at presentation. In all cases, the visual field defect remained stable. One patient developed a similar defect in the fellow eye after an interval of 5 years. Here we describe 13 cases of acquired, stationary temporal wedge scotomas, novel in the literature. Although the aetiology is uncertain, we propose damage to the nasal rim of the optic disc as a likely mechanism.

Optic Perineuritis

Optic perineuritis (OPN) is now defined as "a form of idiopathic orbital inflammatory disease, in which the specific target tissue is the optic nerve sheath". It may be idiopathic or may occur as part of an underlying systemic inflammatory disease. It is a rare disorder and information regarding its presentation and management is only available in case reports and small case series. This review will discuss the contribution of these recent articles to what is known about idiopathic and secondary OPN. Suggestions will also be made as to how to investigate and treat a patient presenting with OPN.

The Evolution of an Optic Nerve Head Granuloma Due to Sarcoidosis

Sarcoidosis can affect the optic nerves by means of optic disc oedema secondary to posterior uveitis, optic disc oedema secondary to raised intracranial pressure, optic neuritis, optic atrophy secondary to compression or infiltration from a primary central nervous system lesion, and primary granuloma of the optic nerve head. The authors report the use of optical coherence tomography in assessing the response to immunosuppression in a 57-year-old woman with an optic nerve head granuloma.

Internuclear ophthalmoplegia associated with anti-TNFα medication

AIM

To describe the presentation of an internuclear ophthalmoplegia (INO) associated with the use of anti-tumor necrosis factor α (anti-TNFα) medication.

METHODS

A case report of a woman, aged 27 years, who developed facial numbness, blurred vision, and diplopia on right gaze. She had a history of Crohn's disease, which was being treated by the anti-TNFα drug, adalimumab. On examination, a left INO was found.

TREATMENT

The patient was prescribed a short course of corticosteroids and adalimumab treatment was discontinued.

RESULTS

Magnetic resonance imaging demonstrated typical demyelinating lesions including one responsible for the INO. Following a short course of corticosteroids and the discontinuation of the adalimumab treatment, the INO resolved, resulting in a swift improvement of ocular motility over a 2-week period.

CONCLUSION

Anti-TNFα therapies have been associated with the development of demyelinating diseases. The presentation of a brainstem syndrome in a patient on anti-TNFα therapy should lead to investigation for central nervous system demyelination and cessation of the medication.

Relapsing-Remitting Sixth Nerve Palsy in Association with Ollier's Disease

Relapsing-remitting sixth nerve palsy is usually due to ophthalmoplegic migraine (recurrent cranial nerve palsy) in younger patients and microvascular disease in older patients. There have been isolated reports, however, of it occurring in the presence of a skull base tumour. We report a 20-year-old woman with Ollier's disease who presented with a relapsing-remitting sixth nerve palsy. Neuro-imaging revealed a skull base enchondroma.

Unilateral compressive optic neuropathy due to skull hyperostosis secondary to nutritional vitamin A deficiency

We report a 17-year-old boy who presented with a chronic left unilateral optic neuropathy. Computerized tomography and magnetic resonance imaging demonstrated compression of the left optic nerve due to skull hyperostosis. He was found to be profoundly vitamin A deficient secondary to an unusual diet consisting predominantly of potato chips and crisps. Skull hyperostosis with cranial neuropathies and other neurological abnormalities has been described in growing animals fed vitamin A deficient diets but has not been previously reported in humans.

Visual Outcomes from Shunting for Idiopathic Intracranial Hypertension

A retrospective notes review was conducted for 50 consecutive patients who underwent shunt surgery for idiopathic intracranial hypertension (IIH). The decimal visual acuity and the mean radial degrees (MRD) of the I4e isopter of the Goldmann visual field were measured pre-operatively and after a mean follow-up period of 1123 days (range: 13-3551 days). A ventriculo-peritoneal shunt was the first procedure in 38 patients and a lumbo-peritoneal shunt in 12. The mean decimal visual acuity of the worse affected eye improved from 0.75 to 0.84, p = 0.011. The MRD score of the worse affected eye improved on average from 25.6° to 35.5°, p < 0.0001. In those with significant pre-operative visual impairment in their worse affected eye (defined as an MRD score ≤30°), the MRD score improved on average from 10.3° to 26.5°, p = 0.0008. The mean number of surgical procedures for each patient was 2.8 (range: 1-15). Taking all surgical procedures into account, post-operative complications were experienced by 30 patients. At last follow-up, 28 patients still complained of headache, 8 of whom had the intervention performed primarily for headache. Shunting can improve visual function in patients with IIH. There is significant post-operative morbidity and often the need for repeated procedures. Headache also commonly remains in these patients. There is a need for a randomised controlled trial of operative interventions in IIH. Sample size calculations for such a trial to treat significant vision loss are presented.

Neuro-ophthalmological Complications of Chronic Inflammatory Demyelinating Polyradiculoneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) can lead to prominent nerve hypertrophy, which can mimic other forms of neuropathy radiologically. Neuro-ophthalmological complications can also occur in CIDP, either at presentation or chronically in the disorder. This can also cause diagnostic difficulties. We report three cases of neuro-ophthalmological complications of CIDP: two cases of papilloedema and one case of proptosis. In all three cases cranial nerve hypertrophy was present. CIDP should be considered in neuro-ophthalmological presentations associated with cranial/spinal nerve root hypertrophy.

A longitudinal functional MRI study of non-arteritic anterior ischaemic optic neuropathy patients

BACKGROUND

Non-arteritic anterior ischaemic optic neuropathy (NA-AION) can cause disabling visual loss and traditionally, visual prognosis has been considered poor, although recent studies have demonstrated improvements in visual acuity in about 30% of patients over time. The aim of the study was to determine whether there was significant cortical reorganisation with functional MRI (fMRI) after acute NA-AION by comparing affected individuals with healthy controls.

METHODS

9 patients with NA-AION were studied acutely and then after 1, 2, 3 and 6&emsp14;months. 23 healthy volunteers underwent scanning at least twice. At each time point, patients were assessed clinically and with fMRI. For the fMRI experiments, subjects underwent monocular visual stimulation (wearing goggles with flashing LED displays).

RESULTS

When stimulating the affected eye, occipital activation was reduced in patients compared with controls. Also, within the NA-AION group, activation in the right Brodmann areas (BA) 44 and 45 was seen during the early phase of the condition. The same areas were activated within the NA-AION group several months later for fellow eye stimulation. When the NA-AION and healthy control groups were formally compared however, these areas (BA 44/45) were not significantly different. NA-AION subjects did show greater activation in visual related areas compared with controls when stimulating the fellow eye. Visual acuity was correlated with more occipital cortex activation when stimulating the affected eye.

CONCLUSIONS

There is cortical re-organisation of the fMRI response in extra-visual areas, seen when both affected and fellow eyes are stimulated after NA-AION.

The incidence and prevalence of idiopathic intracranial hypertension in Sheffield, UK

BACKGROUND AND PURPOSE

The purpose of this study was to identify the incidence and prevalence of idiopathic intracranial hypertension (IIH) in Sheffield, UK.

METHODS

A retrospective review of case notes was conducted to identify cases of IIH seen between 1 January 2007 and 31 December 2008.

RESULTS

Sixteen (15 women and 1 man) new patients were identified to give an incidence within Sheffield of 1.56/100,000/year and 2.86/100,000/year for women. The incidence of IIH in obese women was 11.9/100,000/year. The prevalence of IIH was calculated as 10.9/100,000, and 85.7/100,000 in obese women.

CONCLUSION

A higher incidence of IIH than previously reported UK data was found, which may be because of increasing obesity within the population, or improved case ascertainment.

Bilateral Homonymous Hemianopia with Sparing of the Vertical Meridian

A 19-year-old woman, who was 16 weeks post partum, collapsed with loss of consciousness. Following awakening she suffered abrupt loss of vision. Partial recovery occurred, although she has been left with bilateral homonymous hemianopia with sparing of vision just to the left of the vertical meridian. Magnetic resonance imaging demonstrated bilateral occipital infarcts, sparing the lips of the calcarine sulcus on the right. This is compatible with our expectation that the vertical meridian of the retinotopic map is represented at the superior and inferior lips of the calcarine sulcus.

Modeling axonal degeneration within the anterior visual system: implications for demonstrating neuroprotection in multiple sclerosis

A major objective in multiple sclerosis therapeutics is to develop strategic targeting of specific injury pathways to provide neuroprotection and potentially even restoration. Here we underscore the potential utility of the anterior visual system for the purpose of modeling neuroprotection in response to novel therapies.