The MOG antibody non-P42 epitope is predictive of a relapsing course in MOG antibody-associated disease.

BACKGROUND: Myelin oligodendrocyte glycoprotein (MOG) IgG seropositivity is a prerequisite for MOG antibody-associated disease (MOGAD) diagnosis. While a significant proportion of patients experience a relapsing disease, there is currently no biomarker predictive of disease course. We aim to determine whether MOG-IgG epitopes can predict a relapsing course in MOGAD patients. METHODS: MOG-IgG-seropositive confirmed adult MOGAD patients were included (n=202). Serum MOG-IgG and epitope binding were determined by validated flow cytometry live cell-based assays. Associations between epitopes, disease course, clinical phenotype, Expanded Disability Status Scale and Visual Functional System Score at onset and last review were evaluated. RESULTS: Of 202 MOGAD patients, 150 (74%) patients had MOG-IgG that recognised the immunodominant proline42 (P42) epitope and 115 (57%) recognised histidine103/serine104 (H103/S104). Fifty-two (26%) patients had non-P42 MOG-IgG and showed an increased risk of a relapsing course (HR 1.7; 95% CI 1.15 to 2.60, p=0.009). Relapse-freedom was shorter in patients with non-P42 MOG-IgG (p=0.0079). Non-P42 MOG-IgG epitope status remained unchanged from onset throughout the disease course and was a strong predictor of a relapsing course in patients with unilateral optic neuritis (HR 2.7, 95% CI 1.06 to 6.98, p=0.038), with high specificity (95%, 95% CI 77% to 100%) and positive predictive value (85%, 95% CI 45% to 98%). CONCLUSIONS: Non-P42 MOG-IgG predicts a relapsing course in a significant subgroup of MOGAD patients. Patients with unilateral optic neuritis, the most frequent MOGAD phenotype, can reliably be tested at onset, regardless of age and sex. Early detection and specialised management in these patients could minimise disability and improve long-term outcomes.

A 20-year multicentre retrospective review of optic nerve sheath fenestration outcomes.

Background: Optic nerve sheath fenestration (ONSF) longitudinal outcomes remain unclear and are vital in the assessment of vision failure in patients with raised intracranial pressure (ICP). Furthermore, limited observational data exists regarding its use in other causes of raised ICP. Objective: To determine the efficacy and safety of ONSF for idiopathic intracranial hypertension (IIH), cerebral venous sinus thrombosis (CVST), and other indications. Method: Multicentre study from a tertiary hospital and specialty eye referral hospital in Melbourne, Australia, from July 2000 to December 2020. A total of 116 eyes from 70 patients undergoing ONSF were retrospectively reviewed with patient demographics, surgery indications, visual acuity (VA), visual fields, fundus photos of optic discs, retinal nerve fibre layer (RNFL) thickness, average thickness of optic discs on optical coherence tomography (OCT), and complications recorded. Parametric tests were used to compare the treatment groups pre- and post-operatively. Results: A total of 116 eyes from 70 patients underwent ONSF, which involved 92 eyes with IIH, 9 eyes with CVST, and 15 eyes with other aetiologies ('Other'). Post ONSF, there was a best corrected visual acuity (BCVA) improvement or stabilisation in 84% of patients in all groups, with 50% achieving a BCVA of 6/6 or better at the final follow-up. RNFL, visual fields, and fundus grades all trended towards improvement, with most improvement noted by day 360. Common complications included transient diplopia (n = 29, 25%) and worsening of visual function requiring further cerebrospinal fluid (CSF) diversion procedures (n = 20, 17%). Complications were most significant in the 'Other' group with 1/3 of eyes requiring further CSF diversion procedures. Conclusion: Our data demonstrates effectiveness in the use of ONSF in papilloedema with visual failure due to IIH or CVST and when other CSF diversion procedures or medical therapies have failed.

Developing a Quality Assurance Framework for Neuro-Ophthalmology Using a Multisite Data Registry.

BACKGROUND: Quality assurance (QA) in neuro-ophthalmology (NOPH) is often lacking. We aimed to assess the quality of referral assessment and time to consult for common neuro-ophthalmological conditions by implementing a quality-assurance registry, NODE (Neuro-ophthalmology Database), in a tertiary neuro-ophthalmology clinic. Australian standardized triage categories, namely, P1 (consult ≤30 days), P2 (consult ≤30-60 days), and P3 (consult ≤60-90 days), were developed and validated for neuro-ophthalmological conditions. METHODS: We collected data from NODE on 676 patients at the Alfred Hospital, Melbourne and developed a consensus on the assignation of NOPH conditions to triage categories using a modified Delphi approach. A panel of 7 experienced neuro-ophthalmologists scored conditions and assignation to triage categories. Consensus was considered when ≥75% of the panel strongly agreed or agreed. We analyzed the mean days from referral to triage and from triage to the initial consultation and compared that with the developed triage category standard. RESULTS: Most patients presenting to the service were female (64%). Common diagnoses were idiopathic intracranial hypertension (IIH) (19%), optic neuropathy (ON) (14%), nonspecific headaches (11%), cranial nerve defects (CND) (8%), and papilledema (7%). Consensus on triage category assignment was reached after 2 rounds of scoring from expert panel members. The mean time from referral to triage was performed in <5 days for all the common diagnosis at the NOPH clinic. The mean days (±SD) from P1 category triage to initial consult for IIH was 15 (±12) days, acute ON 16 (±14) days, CND was 20 (±15) days, and papilledema was 20 (±19) days. The mean days from P2 triage to initial consultant for nonspecific headaches was 22 (±20) days and for EOMD was 48 (±22) days. The mean time (days) from P3 triage to initial consultant for nonocular myasthenia gravis was 38 days (±29) days and for visual snow was 54 (±31) days. CONCLUSIONS: We have established a consensus agreement on triage categories for neuro-ophthalmological conditions, which can be further validated using a larger panel of experts. We established a NOPH registry that will serve as a framework to benchmark quality of care between NOPH services. Data from our NOPH registry demonstrated that most conditions are appropriately triaged and seen.

Meta-Analysis of the Use of Head Impulse Test and Head Impulse Test with Direction Changing Nystagmus and Test of Skew Deviation in the Diagnosis of Peripheral Vertigo and Stroke.

INTRODUCTION: The head impulse test (HIT) and HIT combined with direction-changing Nystagmus-Test of Skew deviation (HINTS) have been proposed as bedside tests to differentiate between peripheral and central causes of vertigo in the emergency department (ED). We conducted a meta-analysis of the HIT and HINTS tests to diagnose peripheral vertigo (PV) and central vertigo. METHODS: Pubmed, Google Scholar, EmBase, and articles references published in English up to July 2021 were searched for keywords "vertigo" or "acute vestibular syndrome" or "dizziness" and "head impulse" and "stroke." The bivariate method for meta-analysis was used to calculate positive (PLR) and negative likelihood ratios (NLR) and summary receiver operating characteristics area under the curve (AUC). RESULTS: A total of 11 studies were included analysing both HIT (8 studies, N = 417) and HINTS (6 studies, N = 405). HIT and HINTS were performed within 24 h in 4 of 11 studies. PLR and NLR for HIT in PV was 4.85 (95% CI: 2.83-8.08) and 0.19 (95% CI: 0.12-0.29, I2 63.25%), respectively. The AUC for HIT the diagnosis of PV and stroke was 0.90 and 0.92, respectively. PLR and NLR for a negative HIT in stroke was 5.85 (95% CI: 3.07-10.6) and 0.17 (95% CI: 0.08-0.30), respectively. PLR and NLR for peripheral HINTS pattern for PV was 17.3 (95% CI: 8.38-32.1) and 0.15 (95% CI: 0.07-0.26), respectively. PLR and NLR for central HINTS pattern for stroke: 5.61 (95% CI: 4.19-7.7) and 0.06 (95% CI: 0.03-0.12). In all included studies, HIT and HINTS exams were administered by neurology residents or neurology specialists with additional neuro-otology or neuro-ophthalmology subspeciality experience, and two studies included ED physicians. Raters reported high degree of bias and high concern regarding applicability in most domains of the quality assessment of diagnostic accuracy studies (QUADAS-2) tool. Meta-regression did not demonstrate a statistically significant effect of publication year, time to test, and type of assessor on sensitivity or false positive rate. CONCLUSION: The HIT and HINTS exams appear to be moderately good discriminators of central and PV. However, in most papers, the tests were administered by neurologists and were evaluated beyond 24 h, which may limit utility in the ED setting.

Ophthalmic manifestations of Cryptococcus gattii species complex: a case series and review of the literature.

AIM: To report 4 cases of Cryptococcus gattii (C. gattii) species complex infection with diverse ophthalmic manifestations, and to review the literature to examine pathobiology of disease, classical ophthalmic presentations and outcomes, and treatment modalities for this emerging pathogen. METHODS: Cases of C. gattii meningoencephalitis with ophthalmic manifestations were identified via chart review at two institutions in Australia and one institution in the mid-west region of the United States and are reported as a case series. Additionally, a MEDLINE literature review was conducted to identify all reported cases of C. gattii with ophthalmic manifestations from 1990-2020. Cases were reviewed and tabulated, together with our series of patients, in this report. RESULTS: Four cases of C. gattii with ophthalmic manifestations are presented; three from Australia and one from the USA. A literature review identified a total of 331 cases of C. gattii with visual sequelae. The majority of cases occurred in immunocompetent individuals. Blurred vision and diplopia were the most common presenting symptoms, with papilloedema the most common sign, reported in 10%-50% of cases. Visual loss was reported in 10%-53% of cases, as compared to rates of visual loss of 1%-9% in C. neoformans infection. Elevated intracranial pressure, cerebrospinal fluid (CSF) fungal burden, and abnormal neurological exam at presentation correlated with poor visual outcomes. The mainstays of treatment are anti-fungal agents and aggressive management of intracranial hypertension with serial lumbar punctures. CSF diversion procedures should be considered for refractory cases. Acetazolamide and mannitol are associated with high complication rates, and adjuvant corticosteroids have demonstrated higher mortality rates; these treatments should be avoided. CONCLUSION: Permanent visual loss represents a devastating yet potentially preventable sequelae of C. gattii infection. Intracranial hypertension needs to be recognised early and aggressively managed. Referral to an ophthalmologist/neuro-ophthalmologist in all cases of cryptococcal infection independent of visual symptoms at time of diagnosis is recommended.

Discovering themes in medical records of patients with psychogenic non-epileptic seizures.

INTRODUCTION: Epileptic and psychogenic non-epileptic seizures (PNES) are common diagnostic problems encountered in hospital practice. This study explores the use of unsupervised machine learning in discovering themes in medical records of patients presenting with PNES. We hypothesised that themes generated by machine learning are comparable with the classification by human experts. METHODS: This is a retrospective analysis of the medical records in the emergency department of patients (age >18 years) with PNES who underwent inpatient video-electroencephalography monitoring from May 2009 to June 2014 and received a final diagnosis of PNES. Prior to machine learning of written text, we applied a standardised approach in natural language processing to create a document-term matrix (removal of numbers, stop-words and punctuations, transforming fonts to lower case). The words were separated into tokens and treated as if existing within a bag-of-words. A probability of each word existing within a topic (theme) was modelled on multivariate Dirichlet distribution (R Foundation, V.3.5.0). Next, we asked four experts to independently provide a clinical interpretation of the generated topics. When the majority of (≥3) experts agreed, it was regarded as highly congruent. Interactive data are available on the web at (https://gntem2.github.io/PNES/%23topic=1&lambda=0.6&term=). RESULTS: There were 39 patients (74.4% women, median age 35 years with range 20-82). A total of 121 documents were converted to text files for text mining. There were 15 generated topics with 12/15 topics rated as highly congruent. The main themes were about descriptors of seizures and medication use. CONCLUSIONS: The findings from machine learning on PNES-related documentation provides evidence for the feasibility of applying machine-learning methodology to analyse large volumes of medical records. The topics generated by machine learning were congruent with interpretations by clinicians indicating this method can be used for screening of medical conditions among large volumes of medical records.

Homonymous hemiatrophy of ganglion cell layer from retrochiasmal lesions in the visual pathway.

OBJECTIVE: To determine the temporal evolution, morphology, and frequency of macular ganglion cell atrophy in patients with retrochiasmal lesions of the visual pathway. METHODS: In a consecutive retrospective case series, we identified 47 patients with homonymous hemianopia and accessible macular optical coherence tomography scans. We estimated the time of lesion onset and the location of the lesion within the afferent visual pathway. Using semiautomatic layer segmentation, we determined ganglion cell layer thickness in areas projecting to the side of the retrochiasmal lesion and compared it with ganglion cell layer thickness on the healthy side. RESULTS: We found that retrochiasmal lesions at any level may be associated with an atrophy of ganglion cells. This atrophy respects the vertical midline through the fovea and thus the anatomic separation of the nasal and temporal visual field. The vertical line separating the affected from the unaffected side has significantly less tilt as compared with the disc-fovea angle. Lesions of the optic tract are associated with earlier macular ganglion cell atrophy than retrogeniculate lesions. Macular ganglion cell atrophy may be present in cases with normal peripapillary nerve fiber layer analysis and vice versa. CONCLUSIONS: Macular ganglion cell layer thickness shows a topographic hemiatrophy in retrochiasmal lesions, which manifests earlier for tract lesions than for retrogeniculate lesions. This additional examination of ganglion cell homonymous hemiatrophy has a higher sensitivity in detecting retrograde transsynaptic degeneration than the analysis of the peripapillary nerve fiber layer alone.

Characterization of the human myelin oligodendrocyte glycoprotein antibody response in demyelination.

Over recent years, human autoantibodies targeting myelin oligodendrocyte glycoprotein (MOG Ab) have been associated with monophasic and relapsing central nervous system demyelination involving the optic nerves, spinal cord, and brain. While the clinical relevance of MOG Ab detection is becoming increasingly clear as therapeutic and prognostic differences from multiple sclerosis are acknowledged, an in-depth characterization of human MOG Ab is required to answer key challenges in patient diagnosis, treatment, and prognosis. Herein, we investigated the epitope, binding sensitivity, and affinity of MOG Ab in a cohort of 139 and 148 MOG antibody-seropositive children and adults (n = 287 patients at baseline, 130 longitudinal samples, and 22 cerebrospinal fluid samples). MOG extracellular domain was also immobilized to determine the affinity of MOG Ab. MOG Ab response was of immunoglobulin G1 isotype, and was of peripheral rather than intrathecal origin. High affinity MOG Ab were detected in 15% paediatric and 18% adult sera. More than 75% of paediatric and adult MOG Ab targeted a dominant extracellular antigenic region around Proline42. MOG Ab titers fluctuated over the progression of disease, but affinity and reactivity to Proline42 remained stable. Adults with a relapsing course intrinsically presented with a reduced immunoreactivity to Proline42 and had a more diverse MOG Ab response, a feature that may be harnessed for predicting relapse. Higher titers of MOG Ab were observed in more severe phenotypes and during active disease, supporting the pathogenic role of MOG Ab. Loss of MOG Ab seropositivity was observed upon conformational changes to MOG, and this greatly impacted the sensitivity of the detection of relapsing disorders, largely considered as more severe. Careful consideration of the binding characteristics of autoantigens should be taken into account when detecting disease-relevant autoantibodies.

Posterior Reversible Encephalopathy Syndrome and Subarachnoid Hemorrhage After Lumboperitoneal Shunt for Fulminant Idiopathic Intracranial Hypertension.

A 33-year-old woman presented with severe visual loss from fulminant idiopathic intracranial hypertension. Her lumbar puncture opening pressure was 97 cm H2O. Soon after lumboperitoneal shunt surgery, she had a generalized tonic-clonic seizure. Magnetic resonance imaging demonstrated frontal subarachnoid hemorrhage (SAH) and neuroimaging findings consistent with posterior reversible encephalopathy syndrome (PRES). We hypothesize that an abrupt drop in intracranial pressure after lumboperitoneal shunting led to maladjustment of cerebral vascular autoregulation, which caused SAH and PRES.

Interferon beta-1a long-term therapy related to pulmonary arterial hypertension in multiple sclerosis patients.

We report two patients with relapsing remitting multiple sclerosis (RRMS) on interferon (IFN) beta-1a treatment for more than 7 years who developed pulmonary arterial hypertension (PAH). Patient 1 developed severe PAH requiring lung transplantation. Histology showed typical proliferative lesions including plexiform lesions consistent with PAH. Patient 2 ceased IFN beta-1a, and their symptoms stabilised. Both cases highlight IFN beta-1a treatment as a potential risk factor for PAH. PAH needs to be considered as a diagnosis in patients on long-term IFN beta-1a treatment who develop new-onset respiratory symptoms.

Encephalitis-Associated Human Metapneumovirus Pneumonia in Adult, Australia.

Human metapneumovirus pneumonia, most commonly found in children, was diagnosed in an adult with encephalitis. This case suggests that testing for human metapneumovirus RNA in nasopharyngeal aspirate and cerebrospinal fluid samples should be considered in adults with encephalitis who have a preceding respiratory infection.