Explaining predictors of discharge destination assessed along the patients' acute stroke journey.

INTRODUCTION: Accurate prediction of outcome destination at an early stage would help manage patients presenting with stroke. This study assessed the predictive ability of three machine learning (ML) algorithms to predict outcomes at four different stages as well as compared the predictive power of stroke scores. METHODS: Patients presenting with acute stroke to the Canberra Hospital between 2015 and 2019 were selected retrospectively. 16 potential predictors and one target variable (discharge destination) were obtained from the notes. k-Nearest Neighbour (kNN) and two ensemble-based classification algorithms (Adaptive Boosting and Bootstrap Aggregation) were employed to predict outcomes. Predictive accuracy was assessed at each of the four stages using both overall and per-class accuracy. The contribution of each variable to the prediction outcome was evaluated by the ensemble-based algorithm and using the Relief feature selection algorithm. Various combinations of stroke scores were tested using the aforementioned models. RESULTS: Of the three ML models, Adaptive Boosting demonstrated the highest accuracy (90%) at Stage 4 in predicting death while the highest overall accuracy (81.7%) was achieved by kNN (k=2/City-block distance). Feature importance analysis has shown that the most important features are the 24-hour Scandinavian Stroke Scale (SSS) and 24-hour National Institutes of Health Stroke Scale (NIHSS) scores, dyslipidaemia, hypertension and premorbid mRS score. For the initial and 24-hour scores, there was a higher correlation (0.93) between SSS scores than for NIHSS scores (0.81). Reducing the overall four scores to InitSSS/24hrNIHSS increased accuracy to 95% in predicting death (Adaptive Boosting) and overall accuracy to 85.4% (kNN). Accuracies at Stage 2 (pre-treatment, 11 predictors) were not far behind those at Stage 4. CONCLUSION: Our findings suggest that even in the early stages of management, a clinically useful prediction regarding discharge destination can be made. Adaptive Boosting might be the best ML model, especially when it comes to predicting death. The predictors' importance analysis also showed that dyslipidemia and hypertension contributed to the discharge outcome even more than expected. Further, surprisingly using mixed score systems might also lead to higher prediction accuracies.

Rapid, non-contact multifocal visual assessment in multiple sclerosis.

OBJECTIVE: Previous work on temporally sparse multifocal methods suggests that the results are correlated with disability and progression in people with multiple sclerosis (PwMS). Here, we assess the diagnostic power of three cortically mediated sparse multifocal pupillographic objective perimetry (mfPOP) methods that quantified response-delay and light-sensitivity at up to 44 regions of both visual fields concurrently. METHODS: One high-spatial-resolution mfPOP method, P129, and two rapid medium-resolution methods, W12 and W20, were tested on 44 PwMS and controls. W12 and W20 took 82 s to test both visual fields concurrently, providing response delay and sensitivity at each field location, while P129 took 7 min. Diagnostic power was assessed using areas under the receiver operating characteristic (AUROC) curves and effect-size (Hedges' g). Linear models examined significance. Concurrent testing of both eyes permitted assessment of between-eye asymmetries. RESULTS: Per-region response delays and asymmetries achieved AUROCs of 86.6% ± 4.72% (mean ± SE) in relapsing-remitting MS, and 96.5% ± 2.30% in progressive MS. Performance increased with increasing disability scores, with even moderate EDSS 2 to 4.5 PwMS producing AUROCs of 82.1 to 89.8%, Hedge's g values up to 2.06, and p = 4.0e - 13. All tests performed well regardless of any history of optic neuritis. W12 and W20 performed as well or better than P129. CONCLUSION: Overall, the 82-s tests (W12 and W20) performed better than P129. The results suggest that mfPOP assesses a correlate of disease severity rather than a history of inflammation, and that it may be useful in the clinical management of PwMS.

Cardiovascular Rehabilitation for transient ischaemic Attack and Mild Stroke: the CRAMS effectiveness-implementation hybrid study protocol.

BACKGROUND: Internationally, stroke and cardiac rehabilitation clinicians agree that current cardiac rehabilitation models are a suitable secondary prevention program for people following a transient ischaemic attack (TIA) or mild stroke. There is strong evidence for exercise-based cardiac rehabilitation in people with heart disease, however, the evidence for cardiac rehabilitation post-TIA or stroke is limited. Here we will explore the effectiveness and implementation of an integrated (TIA, mild stroke, heart disease) traditional exercise-based cardiovascular rehabilitation (CVR) program for people with TIA or mild stroke over 6-months. METHODS: This type 1 effectiveness-implementation hybrid study will use a 2-arm single-centre assessor-blind randomised controlled trial design, recruiting 140 participants. Adults who have had a TIA or mild stroke in the last 12-months will be recruited by health professionals from hospital and primary healthcare services. Participants will be assessed and randomly allocated (1:1) to the 6-week CVR program or the usual care 6-month wait-list control group. Distance completed in the 6-min walk test will be the primary effectiveness outcome, with outcomes collected at baseline, 6-weeks (complete CVR) and 6-months in both groups. Other effectiveness outcome measures include unplanned cardiovascular disease-related emergency department and hospital admissions, daily minutes of accelerometer moderate-to-vigorous physical activity, body mass index, waist circumference, blood pressure, quality of life, anxiety and depression. Implementation outcomes will be assessed using the Reach, Effectiveness, Adoption, Implementation, Maintenance (RE-AIM) framework, including a cost-effectiveness analysis. Semi-structured interviews will be conducted with participants and CVR program health professionals, investigating the acceptability, value, and impact of the CVR program. Qualitative analyses will be guided by the Consolidated Framework for Implementation Research. DISCUSSION: Few studies have assessed the effectiveness of cardiac rehabilitation for people with TIA and mild stroke, and no studies appear to have investigated the cost-effectiveness or implementation determinants of such programs. If successful, the CVR program will improve health outcomes and quality of life of people who have had a TIA or mild stroke, guiding future research, policy, and clinical practice, reducing the risk of repeat heart attacks and strokes for this population. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12621001586808 , Registered 19 November 2021.

The role of machine learning in developing non-magnetic resonance imaging based biomarkers for multiple sclerosis: a systematic review.

BACKGROUND: Multiple sclerosis (MS) is a neurological condition whose symptoms, severity, and progression over time vary enormously among individuals. Ideally, each person living with MS should be provided with an accurate prognosis at the time of diagnosis, precision in initial and subsequent treatment decisions, and improved timeliness in detecting the need to reassess treatment regimens. To manage these three components, discovering an accurate, objective measure of overall disease severity is essential. Machine learning (ML) algorithms can contribute to finding such a clinically useful biomarker of MS through their ability to search and analyze datasets about potential biomarkers at scale. Our aim was to conduct a systematic review to determine how, and in what way, ML has been applied to the study of MS biomarkers on data from sources other than magnetic resonance imaging. METHODS: Systematic searches through eight databases were conducted for literature published in 2014-2020 on MS and specified ML algorithms. RESULTS: Of the 1, 052 returned papers, 66 met the inclusion criteria. All included papers addressed developing classifiers for MS identification or measuring its progression, typically, using hold-out evaluation on subsets of fewer than 200 participants with MS. These classifiers focused on biomarkers of MS, ranging from those derived from omics and phenotypical data (34.5% clinical, 33.3% biological, 23.0% physiological, and 9.2% drug response). Algorithmic choices were dependent on both the amount of data available for supervised ML (91.5%; 49.2% classification and 42.3% regression) and the requirement to be able to justify the resulting decision-making principles in healthcare settings. Therefore, algorithms based on decision trees and support vector machines were commonly used, and the maximum average performance of 89.9% AUC was found in random forests comparing with other ML algorithms. CONCLUSIONS: ML is applicable to determining how candidate biomarkers perform in the assessment of disease severity. However, applying ML research to develop decision aids to help clinicians optimize treatment strategies and analyze treatment responses in individual patients calls for creating appropriate data resources and shared experimental protocols. They should target proceeding from segregated classification of signals or natural language to both holistic analyses across data modalities and clinically-meaningful differentiation of disease.

Assessing migraine patients with multifocal pupillographic objective perimetry.

BACKGROUND: To establish the effects of stimulating intrinsically-photosensitive retinal ganglion cells (ipRGCs) on migraine severity, and to determine if migraine produces objectively-measured visual field defects. METHODS: A randomized, open labelled, crossover study tested migraineurs and normal controls using multifocal pupillographic objective perimetry (mfPOP) with 44 test-regions/eye. A slow blue protocol (BP) stimulated ipRGCs, and a fast yellow protocol (YP) stimulated luminance channels. Migraine diaries assessed migraine severity. Per-region responses were analyzed according to response amplitude and time-to-peak. RESULTS: Thirty-eight migraineurs (42.0 ± 16.5 years, 23 females) and 24 normal controls (39.2 ± 15.2 years, 14 females) were tested. The proportion of subjects developing a migraine did not differ after either protocol, either during the 1st day (odds ratio 1.0; 95% confidence interval 0.2-4.4, p = 0.48) or during the first 3 days after testing (odds ratio 0.8; 95% confidence interval 0.3-2.1, p = 0.68). Migraine days/week did not increase following testing with either protocol in comparison to the baseline week (1.4 ± 1.6 pre-testing (mean ± SD), 1.3 ± 1.4 post-BP, and 1.3 ± 1.2 post-YP; p = 0.96), neither did other measures of severity. Migraine occurring up to 2 weeks before testing significantly lowered amplitudes, - 0.64 ± 0.14 dB (mean ± SE), while triptan use increased amplitudes by 0.45 ± 0.10 dB, both at p < 0.001. CONCLUSIONS: Stimulating ipRGCs did not affect migraine occurrence or severity. Pupillary response characteristics were influenced by the occurrence of a recent migraine attack and a history of triptan use.

'They're getting a taste of our world': A qualitative study of people with multiple sclerosis' experiences of accessing health care during the COVID-19 pandemic in the Australian Capital Territory.

BACKGROUND: People with multiple sclerosis (MS), who are often immunocompromised, require complex care and engage with a variety of health-care providers to manage their health. OBJECTIVE: To elucidate people with MS' experiences of accessing health care during the COVID-19 pandemic in Australia. DESIGN: A qualitative study involving semi-structured interviews and thematic analysis. SETTINGS AND PARTICIPANTS: Eight adults with a clinical diagnosis of MS participated in telephone or video call interviews between June and July 2020. RESULTS: Participants were aware that having MS made them more vulnerable to contracting COVID-19. In some cases, usual care was postponed or not sought. Some circumstances warranted the risk of a face-to-face consultation. Benefits of telehealth consultations included improved access, convenience and being contact-free. In comparison with video consultations, those via telephone were considered less personal and limited capacity to read body language, and for physical examination. Most participants hoped to incorporate telehealth into their future health-care routines. DISCUSSION AND CONCLUSION: Personal risk assessment and trust in health-care professionals are determinants of the mode through which people with MS accessed health care during the COVID-19 pandemic. Telehealth has been a valuable tool to mitigate COVID-19 transmission through enabling contact-free consultations. People with MS may find specific value in video consultations, which enable visualization of physical function. There is a need for training and support for all clinicians to conduct remote consultations. PATIENT OR PUBLIC CONTRIBUTION: This study was conducted by a team comprised of four people with MS, a neurologist and four health services researchers.

Variation in the Anatomy of the Normal Human Optic Chiasm: An MRI Study.

BACKGROUND: Compression of the optic chiasm typically leads to bitemporal hemianopia. This implies that decussating nasal fibers are selectively affected, but the precise mechanism is unclear. Stress on nasal fibers has been investigated using finite element modeling but requires accurate anatomical data to generate a meaningful output. The precise shape of the chiasm is unclear: A recent photomicrographic study suggested that nasal fibers decussate paracentrally and run parallel to each other in the central arm of an "H." This study aimed to determine the population variation in chiasmal shape to inform future models. METHODS: Sequential MRI scans of 68 healthy individuals were selected. 2D images of each chiasm were created and analyzed to determine the angle of elevation of the chiasm, the width of the chiasm, and the offset between the points of intersection of lines drawn down the centers of the optic nerves and contralateral optic tracts. RESULTS: The mean width of the chiasm was 12.0 ± 1.5 mm (SD), and the mean offset was 4.7 ± 1.4 mm generating a mean offset:width ratio of 0.38 ± 0.09. No chiasm had an offset of zero. The mean incident angle of optic nerves was 56 ± 7°, and for optic tracts, it was 51 ± 7°. CONCLUSIONS: The human optic chiasm is "H" shaped, not "X" shaped. The findings are consistent with nasal fibers decussating an average of 2.4 mm lateral to the midline before travelling in parallel across the midline. This information will inform future models of chiasmal compression.

Anticoagulant prescribing in patients with ischaemic stroke: what has changed over a decade?

A study at our institution conducted 10 years ago identified that warfarin was under-utilised in patients with atrial fibrillation. We replicated this study and compared the results. There was a significant increase in the proportion of patients appropriately anticoagulated (63% vs 9%, P < 0.001). Eighty-seven percent of eligible patients were appropriately anticoagulated on discharge (86% previously). Seventy-two percent of treated patients were prescribed a direct oral anticoagulant. Of these, 10% were discharged with a sub-therapeutic dose without obvious explanation.

'It struck at the heart of who I thought I was': A meta-synthesis of the qualitative literature examining the experiences of people with multiple sclerosis.

BACKGROUND: People with multiple sclerosis (MS) have varied experiences and approaches to self-management. This review aimed to explore the experiences of people with MS, and consider the implications of these experiences for clinical practice and research. METHODS: A meta-synthesis of the qualitative literature examining experiences of people with MS was conducted using systematic searches of ProQuest, PubMed, CINAHL and PsycINFO. We incorporated feedback from team members with MS as expert patient knowledge-users to capture the complex subjectivities of persons with lived experience responding to research on lived experience of the same disease. RESULTS: Of 1680 unique articles, 77 met the inclusion criteria. We identified five experiential themes: (a) the quest for knowledge, expertise and understanding, (b) uncertain trajectories (c) loss of valued roles and activities, and the threat of a changing identity, (d) managing fatigue and its impacts on life and relationships, and (f) adapting to life with MS. These themes were distributed across three domains related to disease (symptoms; diagnosis; progression and relapse) and two contexts (the health-care sector; and work, social and family life). CONCLUSION: The majority of people in the studies included in this review expressed a determination to adapt to MS, indicating a strong motivation for people with MS and clinicians to collaborate in the quest for knowledge. Clinicians caring for people with MS need to consider the experiential and social outcomes of this disease such as fatigue and the preservation of valued social roles, and incorporate this into case management and clinical planning.

Correlation of MRI Findings With Patterns of Visual Field Loss in Patients With Pituitary Tumors.

BACKGROUND: Compression of the optic chiasm by pituitary tumors typically results in bitemporal hemianopia, implying that nasal retinal fibers are preferentially damaged. The reason for this is not clear. One theory suggests that nasal fibers are selectively vulnerable simply because they cross each other. This study investigated the "crossing theory" by correlating visual field (VF) loss with chiasmal elevation and with the degree of eccentric compression on MRI scans. METHODS: Our hospital database was searched to identify patients with a) chiasmal compression by a pituitary tumor; b) documented preoperative evidence of VF loss; and c) preoperative MRI scan performed within 1 month of VF testing. Temporality and bitemporality indices were derived from pattern deviation VF plots. Elevations of the central and peripheral parts of the chiasm were obtained from MRI scans, from which the eccentricity of compression was calculated. Temporality indices and hemifield loss were compared with central chiasmal elevation, and nasal hemifield loss in each eye was plotted against eccentricity. RESULTS: Eleven patients were suitable for analysis. The degree of bitemporal VF involvement was significantly correlated with elevation of the central chiasm (P = 0.004). However, there was minimal involvement of nasal VFs, and no demonstrable increase in nasal field loss with increasing eccentricity of compression. CONCLUSIONS: This study provides support for the crossing theory. These findings will inform further finite element models of chiasmal compression. A larger, prospective study is planned.

Central control of eye movements.

PURPOSE OF REVIEW: Eye-movement research continues to provide an excellent tool for understanding the central control of motor function, both in health and disease. This article reviews recent findings in relation to saccadic eye movements, particularly antisaccades and microsaccades, with particular emphasis on the control of inaction, something which has recently become topical. RECENT FINDINGS: Microsaccades are under the control of the cerebral cortex, particularly the frontal and parietal eye fields. Their frequency and direction alters following presentation of visual stimuli. Spontaneous alterations in their frequency are correlated with alterations in the frequency of the gamma-band activity in the visual cortex as well as, interestingly, the heartbeat. Studies of saccades in Parkinson's disease have demonstrated abnormalities of prosaccade suppression which have variously been shown to correlate with freezing of gait, postural instability, minimal cognitive change and stimulation of the subthalamic nuclei. In stroke patients, abnormal patterns of saccade activity are associated with poor performance on reaching studies when using the weak arm. SUMMARY: Eye-movement studies continue to provide new insights into the control of movement in general but have been particularly useful in investigating the process of suppressing unwanted movement.

Australian driving restrictions: how well do neurologists know them?

Driving regulations are complex, particularly for neurological conditions, but accurate application of restrictions is important. This study was designed to investigate knowledge of the Austroads guidelines in medical students, neurological trainees and consultant neurologists using a questionnaire addressing both private and commercial licence restrictions related to five common neurological conditions, namely transient ischaemic attack (TIA), vasovagal episode, unwitnessed blackout, first epileptic seizure and benign paroxysmal positional vertigo. In total, 118 of the 120 returned responses could be analysed. Overall, 50% of all responses were correct. Respondents performed better for private than commercial licences, and consultants performed better than trainees and students. The highest proportion of correct answers was seen for vasovagal attack, and the lowest for TIA. In summary, knowledge of driving restrictions was relatively poor, and regular consultation of the guidelines is recommended. A larger study is warranted and increased education at both medical school and postgraduate levels should be considered.

The Visual Agnosias and Related Disorders.

BACKGROUND: There are many disorders of higher visual processing that result from damage to specific areas of the cerebral cortex that have a specific role in processing certain aspects (modalities) of vision. These can be grouped into those that affect the ventral, or "what?", pathway (e.g., object agnosia, cerebral achromatopsia, prosopagnosia, topographagnosia, and pure alexia), and those that affect the dorsal, or "where?", pathway (e.g., akinetopsia, simultanagnosia, and optic ataxia). EVIDENCE ACQUISITION: This article reviews pertinent literature, concentrating on recent developments in basic science research and studies of individual patients. RESULTS: An overview of the current understanding of higher cerebral visual processing is followed by a discussion of the various disorders listed above. CONCLUSIONS: There has been considerable progress in the understanding of how the extrastriate visual cortex is organized, specifically in relation to functionally specialized visual areas. This permits a better understanding of the individual visual agnosias resulting from damage to these areas.

Cystic Optic Chiasm Lesion: Atypical Magnetic Resonance Imaging Findings.

Intrinsic cystic lesions in the optic chiasm are an uncommon cause of bitemporal hemianopia compared with compressive lesions extrinsic to the chiasm. A 40-year-old man presented with difficulty driving. Clinical assessment revealed a bitemporal hemianopia. Magnetic resonance imaging showed an unusual cystic appearance of the chiasm. The appearance was felt to be most likely secondary to previous infective or inflammatory disease, but biopsy was not undertaken given the very significant risk of further visual loss.

Mimics and chameleons of optic neuritis.

Optic neuritis is a common problem and most neurologists are familiar with it. Recent studies have suggested that it can be overdiagnosed in as many as 10% of cases. The major reasons for this relate to confusion regarding terminology and lack of familiarity with common mimics. This article covers typical 'idiopathic' demyelinating optic neuropathy (IDON) and several possible variations in the way it can present (chameleons). We then discuss several conditions that can mimic IDON, including neuromyelitis optica, sarcoidosis, chronic relapsing inflammatory optic neuropathy, anterior ischaemic optic neuropathy, infectious/parainfectious optic neuropathy, neuroretinitis, Leber's hereditary optic neuropathy, and some 'ocular' mimics including autoimmune retinopathy and central serous choroidoretinopathy.

Septic Cavernous Sinus Thrombosis: Case Report and Review of the Literature.

Septic cavernous sinus thrombosis is a rare but serious complication of infection of the cavernous sinuses. There are no randomised, controlled trials of management of this condition and existing reviews of the literature are somewhat dated. The authors report a case with a favourable outcome and then present the findings of a literature review of the management of this condition. Outcome data suggest that corticosteroids are of equivocal benefit whereas antibiotics and anticoagulation are beneficial.

Tonsillar Herniation After Lumbar Puncture in Idiopathic Intracranial Hypertension.

A 30-year-old woman with coexisting renal tubular acidosis and idiopathic intracranial hypertension (IIH), treated with acetazolamide, experienced coning (cerebellar tonsillar herniation) after a lumbar puncture (LP). Brain magnetic resonance imaging at initial diagnosis of IIH showed minor tonsillar descent and computed tomographic venography revealed hypoplasia of the left transverse sinus. The patient previously had three uneventful LPs, all of which showed high opening pressures and normal cerebrospinal fluid composition. In retrospect, it was noted that her serum bicarbonate had fallen to 9 mmol/L (normal: 22-28 mm/L) 1 week before the LP. We hypothesize that the combination of cerebral edema (due to worsening metabolic acidosis), poor venous drainage, and preexisting minor tonsillar descent contributed to her post-LP coning.