Is it ethical to use teriflunomide as an active comparator in phase 3 trials?

Ethical concerns have been raised about the practice of using teriflunomide, an oral licensed disease-modifying therapy, as an active comparator in phase 3 multiple sclerosis (MS) trials. The assumption is based on the perceived low efficacy of teriflunomide as judged by its effect on relapses and focal MRI activity. However, when you look beyond focal inflammation, teriflunomide has a robust impact on disability progression and a similar effect to the anti-CD20 monoclonal antibody therapies on slowing down the accelerated brain volume loss associated with MS. Teriflunomide is also more effective when used second or third line. The other classes of disease-modifying therapies have problems with their use as active comparators in clinical trials. Using a non-inferiority or equivalence trial design has its own unique set of regulatory and ethical challenges and is not necessarily a solution. There are also economic, altruistic and pragmatic reasons for continuing to use teriflunomide as an active comparator in MS clinical trials. An online survey indicates that the majority of the MS community feels it is still ethical to randomise subjects to teriflunomide and that procedures can be put in place to protect trial subjects randomised to teriflunomide. Therefore, we still have equipoise, and teriflunomide comparator trials are ethical.

CNS resilience in the progression of MS

Resilience; Progressive multiple sclerosis; Genomics.

Myopia in late adolescence and subsequent multiple sclerosis among men

BACKGROUND

Risk factors such as low vitamin D level has been implicated in the etiology of multiple sclerosis (MS) and may be relevant to myopia, such that there may be an association between myopia and MS.

METHODS

Using linked Swedish national register data, we conducted a cohort study of men who were born in Sweden between 1950 and 1992, lived in Sweden between 1990 and 2018, and enrolled in military conscription assessment (n = 1,847,754). Myopia was defined based on the spherical equivalent refraction measured at conscription assessment, around age 18 years. Multiple sclerosis was identified using the Patient Register. Cox regression produced hazard ratios (HR) with 95% confidence intervals (95% CI), with adjustment for demographic and childhood socioeconomic characteristics and residential region. Due to changes in the assessment of refractive error, the analysis was stratified into two groups by the year of conscription assessment: 1969-1997 and 1997-2010.

RESULTS

Among 1,559,859 individuals during a maximum of 48 years of follow-up from age 20 to 68 years (44,715,603 person-years), there were 3,134 MS events, and the incidence rate 7.0 (95% CI [6.8, 7.3] per 100,000 person-years). Among individuals with conscription assessments during 1997-2010, there were 380 MS events. There was no evidence of an association between myopia and MS, with HR 1.09 (95% CI 0.83, 1.43). Among individuals who underwent conscription assessment in 1969-1997, there were 2754 MS events. After adjusting for all covariates, there was no evidence of an association between myopia and MS (HR 0.99 [95% CI 0.91, 1.09]).

CONCLUSION

Myopia in late adolescence is not associated with a subsequent raised risk of MS and thus there does not appear to be important shared risk factors.

Smell, taste and COVID-19: testing is essential

During the COVID-19 pandemic, it became clear that smell and taste (chemosensory) disturbance is very common in the early stages of disease. This article addresses (i) why COVID-19 specifically targets the modalities of smell and possibly taste and what is the mechanism, (ii) what is the frequency of smell and taste loss and (iii) what is the overall prognosis. It is suggested that mouth-breathers may be at particular risk of COVID-19. Symptom-based questionnaires are likely to under-estimate the prevalence of chemosensory impairment by as much as 50%. The prevalence of smell loss is so high that a person who has normal olfaction on formal testing is unlikely to be infected significantly with Cov-2. Furthermore, someone without symptoms who has an abnormal smell test could still be infected and liable to spread the disease. Brief, low-cost, olfactory tests are available that would permit a high throughput in field stations and airports. A normal result might obviate the need for a nasopharyngeal swab for the Cov-2 virus.

Chemosensory dysfunction in neurodegenerative diseases

A number of neurodegenerative diseases are accompanied by disordered smell function. The degree of dysfunction can vary among different diseases, such that olfactory testing can aid in differentiating, for example, Alzheimer's disease (AD) from major affective disorder and Parkinson's disease (PD) from progressive supranuclear palsy. Unfortunately, altered smell function often goes unrecognized by patients and physicians alike until formal testing is undertaken. Such testing uniquely probes brain regions not commonly examined in physical examinations and can identify, in some cases, patients who are already in the "preclinical" stage of disease. Awareness of this fact is one reason why the Quality Standards Committee of the American Academy of Neurology has designated smell dysfunction as one of the key diagnostic criteria for PD. The same recommendation has been made by the Movement Disorder Society for both the diagnosis of PD and identification of prodromal PD. Similar suggestions are proposed to include olfactory dysfunction as an additional research criterion for the diagnosis of AD. Although taste impairment, i.e., altered sweet, sour, bitter, salty, and umami perception, has also been demonstrated in some disorders, taste has received much less scientific attention than smell. In this review, we assess what is known about the smell and taste disorders of a wide range of neurodegenerative diseases and describe studies seeking to understand their pathologic underpinnings.

Epstein Barr virus shedding in multiple sclerosis: Similar frequencies of EBV in saliva across separate patient cohorts

BACKGROUND

Epstein Barr Virus (EBV) infection is closely associated with multiple sclerosis (MS), but the relationship between viral load and disease activity is unclear. This study tested the observed levels of salivary EBV in MS, as a first step in investigating this relationship.

METHODS

Real-time quantitative PCR (qPCR) was used to measure EBV DNA levels in saliva samples from three separate Multiple Sclerosis (MS) patient cohorts.

RESULTS

The qPCR assay was used to delineate EBV shedding, defined here as a reliably detectable level of extracellular EBV DNA in saliva. Frequency of EBV shedding was found to be similar across the groups, with 20-25% of subjects releasing virus on any given sampling date. Diurnal variation in EBV count was tested in one of the cohorts, in which 26% of subjects showed more than a 10-fold difference between the highest and lowest EBV levels on a single day. In the same cohort, elevated viral levels at one time point did not predict elevated viral levels at a subsequent time point.

CONCLUSIONS

These results indicate that EBV lytic activity in a subject cannot be inferred from a single measure of EBV in saliva. Also, subjects do not appear to be behave constantly as "EBV shedders" or "non-shedders". The assay is useful in giving a clear indication of salivary gland EBV lytic activity across a patient cohort - for example, in testing anti-viral drugs in MS.

PREDICT-PD: An online approach to prospectively identify risk indicators of Parkinson's disease

Background

A number of early features can precede the diagnosis of Parkinson's disease (PD).

Objective

To test an online, evidence‐based algorithm to identify risk indicators of PD in the UK population.

Methods

Participants aged 60 to 80 years without PD completed an online survey and keyboard‐tapping task annually over 3 years, and underwent smell tests and genotyping for glucocerebrosidase (GBA) and leucine‐rich repeat kinase 2 (LRRK2) mutations. Risk scores were calculated based on the results of a systematic review of risk factors and early features of PD, and individuals were grouped into higher (above 15th centile), medium, and lower risk groups (below 85th centile). Previously defined indicators of increased risk of PD (“intermediate markers”), including smell loss, rapid eye movement–sleep behavior disorder, and finger‐tapping speed, and incident PD were used as outcomes. The correlation of risk scores with intermediate markers and movement of individuals between risk groups was assessed each year and prospectively. Exploratory Cox regression analyses with incident PD as the dependent variable were performed.

Results

A total of 1323 participants were recruited at baseline and >79% completed assessments each year. Annual risk scores were correlated with intermediate markers of PD each year and baseline scores were correlated with intermediate markers during follow‐up (all P values < 0.001). Incident PD diagnoses during follow‐up were significantly associated with baseline risk score (hazard ratio = 4.39, P = .045). GBA variants or G2019S LRRK2 mutations were found in 47 participants, and the predictive power for incident PD was improved by the addition of genetic variants to risk scores.

Conclusions

The online PREDICT‐PD algorithm is a unique and simple method to identify indicators of PD risk. © 2017 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Chronic Low-Dose Exposure of Sodium Nitrite in VM-Strain Mice: Central Nervous System Changes

1 There is suggestive evidence that nitrite may be a causative factor in cerebral glioma.

2 To test this hypothesis we selected the VM mouse strain, known for its susceptibility to spontaneous glioma formation, and exposed 300 animals to 0.2% sodium nitrite in their drinking water. One hundred of this group were exposed both in utero and throughout their adult lives. The remaining 200 animals received nitrite from the time of weaning. A further 200 mice were used as controls and received distilled water.

3 All animals were maintained until their natural death and were then subjected to autopsy and routine histological examination.

4 There was no excess of nervous system tumours in the experimental groups.

PREDICT-PD: identifying risk of Parkinson's disease in the community: methods and baseline results

OBJECTIVES

To present methods and baseline results for an online screening tool to identify increased risk for Parkinson's disease (PD) in the UK population.

METHODS

Risk estimates for future PD were derived from the results of a systematic review of risk factors and early features of PD. Participants aged 60-80 years without PD were recruited by self-referral. They completed an online survey (including family history, non-motor symptoms and lifestyle factors), a keyboard-tapping task and the University of Pennsylvania Smell Identification Test. Risk scores were calculated based on survey answers. Preliminary support for the validity of this algorithm was assessed by comparing those estimated to be higher risk for PD with those at lower risk using proxies, including smell loss, REM-sleep behaviour disorder and reduced tapping speed, and by assessing associations in the whole group.

RESULTS

1324 eligible participants completed the survey and 1146 undertook the keyboard-tapping task. Smell tests were sent to 1065 participants. Comparing the 100 highest-risk participants and 100 lowest-risk participants, median University of Pennsylvania Smell Identification Test scores were 30/40 versus 33/40 (p<0.001), mean number of key taps in 30 s were 55 versus 58 (p=0.045), and 24% versus 10% scored above cut-off for REM-sleep behaviour disorder (p=0.008). Regression analyses showed increasing risk scores were associated with worse scores in the three proxies across the whole group (p≤0.001).

CONCLUSIONS

PREDICT-PD is the first study to systematically combine risk factors for PD in the general population. Validity to predict risk of PD will be tested through longitudinal follow-up of incident PD diagnosis.

To tell or not to tell? Revealing the diagnosis in multiple sclerosis

We review briefly (1) the history of patient-physician relationship and its evolution from a physician-centered to patient-centered model; (2) the impact of the McDonald Criteria for Multiple Sclerosis (MS); (3) why it is important to tell patients of their diagnosis; (4) how physicians should disclose the diagnosis to patients; (5) dealing with suspected MS; and (6) prognosis and treatment. For the majority of clinically definite MS patients we advocate disclosure, identify steps for physicians to communicate the diagnosis and propose a framework to follow when revealing a diagnosis of MS.

Risk associated behavior in premorbid multiple sclerosis: A case-control study

BACKGROUND

It is generally accepted that individuals who subsequently develop MS are more likely to be smokers, have suffered glandular fever and to have a low blood vitamin D level. Previous research suggested that a unifying premise is risk-associated behavior before MS onset. This survey explores several health-adverse premorbid behaviors using a case-control design.

METHODS

A questionnaire was completed by 94 patients with clinically definite MS. Their responses were compared to a control group of 59 who were patients with benign headache. Questions explored pre-symptomatic experience of: (a) alcohol, smoking, substance abuse, glandular fever; (b) blood transfusion; (c) hazardous sport, gambling (d) sexual history, gynecologic infection, number of pregnancies, terminations of pregnancy. Data were adjusted for age of first symptoms, gender and smoking.

RESULTS

Compared to the headache group, MS subjects showed significant differences prior to symptom onset, adjusted for age of first symptoms, gender and smoking, with odds ratios for reporting or means and 95% confidence intervals as follows: (a) consuming alcoholic drinks, OR 6.91 (1.74 to 27.45; p=0.006) and at an earlier age, mean 16.9y (16.4 to 17.5; p=0.046) (b) cigarette smoking, OR 2.24 (1.09 to 4.59; p=0.028) and to have smoked more per day, mean 9.45 (5.55 to 13.35; p=0.001) (c) history of glandular fever/infectious mononucleosis, OR 3.07 (1.11 to 8.49; p=0.031); (d) consumed recreational drugs, OR 3.90 (1.32 to 11.50; p=0.014), notably cannabis, OR 4.10 (1.40 to 12.09; p=0.011); (e) used a car seat belt, OR 4.45 (1.43 to 13.83; p=0.010); (f) attended all-night parties, OR 2.45 (1.12 to 5.36; p=0.025); (g) sunbathed, OR 2.770 (1.02 to 7.52; p=0.046); (h) had more sexual partners, mean 3.97 (2.00 to 5.95; p<0.001), more pregnancies, mean 1.43 (0.99 to 1.86; p=0.015) and one or more terminations of pregnancy, OR 5.05 (1.003 to 25.386; p=0.049).

CONCLUSION

All but one of the statistically significant variables (use of car seat belt) supports our hypothesis that MS subjects lead a riskier premorbid lifestyle. Strong associations were found for smoking, alcohol and glandular fever as suggested by others. Novel associations were found for recreational drug use; attending all-night parties; gambling on the lottery; more sexual partners, more pregnancies and one or more terminations of pregnancy. Such behavior during the MS prodrome may expose an individual to a variety of hostile environmental agents.

Meta-analysis of early nonmotor features and risk factors for Parkinson disease

Objective

To evaluate the association between diagnosis of Parkinson disease (PD) and risk factors or early symptoms amenable to population-based screening.

Methods

A systematic review and meta-analysis of risk factors for PD.

Results

The strongest associations with later diagnosis of PD were found for having a first-degree or any relative with PD (odds ratio [OR], 3.23; 95% confidence interval [CI], 2.65–3.93 and OR, 4.45; 95% CI, 3.39–5.83) or any relative with tremor (OR, 2.74; 95% CI, 2.10–3.57), constipation (relative risk [RR], 2.34; 95% CI, 1.55–3.53), or lack of smoking history (current vs never: RR, 0.44; 95% CI, 0.39–0.50), each at least doubling the risk of PD. Further positive significant associations were found for history of anxiety or depression, pesticide exposure, head injury, rural living, beta-blockers, farming occupation, and well-water drinking, and negative significant associations were found for coffee drinking, hypertension, nonsteroidal anti-inflammatory drugs, calcium channel blockers, and alcohol, but not for diabetes mellitus, cancer, oral contraceptive pill use, surgical menopause, hormone replacement therapy, statins, acetaminophen/paracetamol, aspirin, tea drinking, history of general anesthesia, or gastric ulcers. In the systematic review, additional associations included negative associations with raised serum urate, and single studies or studies with conflicting results.

Interpretation

The strongest risk factors associated with later PD diagnosis are having a family history of PD or tremor, a history of constipation, and lack of smoking history. Further factors also but less strongly contribute to risk of PD diagnosis or, as some premotor symptoms, require further standardized studies to demonstrate the magnitude of risk associated with them. ANN NEUROL 2012

Identifying prodromal Parkinson's disease: pre-motor disorders in Parkinson's disease

Increasing recognition that Parkinson's disease (PD) may start outside of the substantia nigra has led to a rapidly expanding effort to define prodromal stages of PD, before motor signs permit classical diagnosis. Many of these efforts center around the identification of clinical non-motor symptoms and signs of disease. There is now direct evidence that olfaction, rapid eye movement (REM) sleep behavior disorder (RBD), constipation, and depression can be present in prodromal PD. In addition, there is suggestive evidence that visual changes, other autonomic symptoms, and subtle cognitive changes may also be present at prodromal stages. A critical issue in utility of these prodromal markers will be assessment of sensitivity, specificity, and positive and negative predictive values. Although these have yet to be fully defined, olfactory deficits, some visual changes, and autonomic symptoms occur in the majority of PD patients at diagnosis, suggesting good potential sensitivity. However, with the exception of RBD and perhaps some specific autonomic measures, specificity, and positive predictive value of these markers may be insufficient to be used alone as identifiers of prodromal disease. The evidence for the utility of olfaction, RBD, autonomic markers, visual changes, mood disorders, and cognitive loss as markers of prodromal PD and the potential sensitivity and specificity of these markers are summarized.

MRI and visual-evoked potentials in partners of multiple sclerosis patients

OBJECTIVE

Some epidemiological evidence, particularly concerning the role of Epstein Barr Virus implies that multiple sclerosis (MS) may be transmissible and if correct, this might be revealed by increased prevalence of MS in cohabiting partners.

METHODS

We addressed this problem by neurological assessment, visual-evoked potentials (VEP) and magnetic resonance imaging (MRI) in 112 partners of patients with MS in comparison to a control group of 93 individuals with clinically non-significant head or neck pain and in comparison to UK prevalence.

RESULTS

We found one instance of conjugal definite MS. Including this case, VEP were abnormal in five instances with either significant delay (n = 3) or increased interocular latency difference (IOLD) (n = 2) in partners of MS patients thus raising the possibility of subclinical optic nerve demyelination. The mean absolute value of IOLD in partners was greater than the value in controls (P = 0.033). There were no significant differences in MRI findings between the two groups.

CONCLUSION

The finding of one conjugal pair and abnormal VEP in a further four MS partners could have several explanations. It is compatible with the concept of a transmissible agent, although our observations could be due to several biases as well as the play of chance alone.

A basic smell test is as sensitive as a dopamine transporter scan: comparison of olfaction, taste and DaTSCAN in the diagnosis of Parkinson's disease

AIM

To evaluate relationship between odour identification, taste threshold, dopamine transporter scan (DaTSCAN) and motor function in early Parkinson's disease (PD) and their diagnostic accuracy.

METHODS

Seventy-three patients with early parkinsonism were evaluated by the Unified Parkinson's Disease Rating Scale (UPDRS), DaTSCAN, electrogustometry (EGM) threshold and University of Pennsylvania Smell Identification Test (UPSIT). Olfactory Event-Related potentials (OERP) were performed on 49 patients. At follow-up (mean 15.3 months), patients were diagnosed as 'PD' or 'non-PD'. DaTSCAN images were assessed visually and semi-quantitatively by QuantiSPECT.

RESULTS

The sensitivity of UPSIT (86%) was not significantly different from that of the DaTSCAN (92%). UPSIT correlated moderately with DaTSCAN uptake (r = 0.44; P < 0.005) and UPDRS score (r = 0.43; P < 0.05) and weakly with symptom duration (r = 0.25; P < 0.05). In the PD group, OERP showed increased latency but no change in amplitude and no correlation with DaTSCAN. EGM thresholds were impaired in 22% of the PD group but they did not correlate with any other test parameters. DaTSCAN-UPSIT discordance was found in nine patients with PD, but neither was diagnostically superior.

CONCLUSION

Our patients with early PD have a frequent and severe olfactory deficit that correlates with disease severity, symptom duration and DaTSCAN but not EGM. The sensitivities of UPSIT and DaTSCAN are high at 86% and 92%, respectively. Although DaTSCAN is superior for 'localization', UPSIT is considerably 'cheaper', and neither is disease specific. EGM threshold impairment in PD is independent of the smell deficit, and probably signifies advanced disease.

Lewy pathology in the submandibular gland of individuals with incidental Lewy body disease and sporadic Parkinson's disease

A retrospective autopsy-based study of the human submandibular gland, one of the three major salivary glands, together with anatomically related peripheral structures (cervical superior ganglion, cervical sympathetic trunk, vagal nerve at the level of the carotid bifurcation), was conducted on a cohort consisting of 33 individuals, including 9 patients with neuropathologically confirmed Parkinson's disease (PD), three individuals with incidental Lewy body disease (iLBD), 2 individuals with neuropathologically confirmed multiple system atrophy (MSA), and 19 controls, using alpha-synuclein immunohistochemistry in 100 mum polyethylene glycol-embedded tissue sections. Lewy pathology (LP) was present in the submandibular glands and cervical superior ganglia in PD (9/9 cases) and iLBD (2/3 cases) but not in MSA or controls. The cervical sympathetic trunk (7/9 PD cases, 2/3 iLBD cases) and peripheral vagal nerves (9/9 PD cases, 2/3 iLBD cases) also displayed LP. The results are discussed within the context of hyposmia as well as autonomic dysfunction in PD (sialorrhea, sialopenia, dysphagia). Potential disease-related changes in salivary volume, contents, and viscosity might make it possible, in combination with other tests, to employ human saliva as a biomarker.

The McDonald Criteria for Multiple Sclerosis: time for clarification

The McDonald Criteria for Multiple Sclerosis in general have replaced the Poser criteria. Despite this, many consider that there are still areas of ambiguity. In this study, neurologists completed a questionnaire about familiarity with, usefulness and applicability of the McDonald Criteria for Multiple Sclerosis. Understanding of 'attack'; objective clinical evidence; 'two or more lesions' and their ability to interpret case scenarios was evaluated. Responses were analysed overall and by skill group. Ninety-seven consultants and 30 trainees responded, of whom 37 operated a multiple sclerosis clinic ('experts'). Some (62%) thought the McDonald Criteria for Multiple Sclerosis were useful, and 31% found them confusing or difficult to apply; 38% thought the criteria should be applied universally, others (14-28%) favoured their use for drug trials/research, and 17% rarely used them. Thirty-six (29.1%) thought the McDonald Criteria for Multiple Sclerosis specified two categories: 'MS and not MS', but others considered 'possible' or 'probable' multiple sclerosis were permitted. Experts understood better 'an attack' and 'objective clinical evidence'. All skill groups comprehended poorly what constituted an episode of demyelination, and whether Lhermitte's phenomenon was acceptable as evidence for cervical cord demyelination. A consistent response was given by 44-50% to 'two or more lesions', although this is not well defined. Criteria for primary progressive multiple sclerosis were understood well. We conclude that the McDonald Criteria for Multiple Sclerosis have improved diagnosis but areas of misinterpretation remain, particularly the definition of 'an attack', 'objective clinical evidence' and 'two or more lesions'. There was uncertainty about how many multiple sclerosis categories were permitted and whether the terms 'possible' and 'probable' were allowable. Further clarification might allow the criteria to be applied more consistently.