Endemic parkinsonism: clusters, biology and clinical features.

The term 'endemic parkinsonism' refers to diseases that manifest with a dominant parkinsonian syndrome, which can be typical or atypical, and are present only in a particular geographically defined location or population. Ten phenotypes of endemic parkinsonism are currently known: three in the Western Pacific region; two in the Asian-Oceanic region; one in the Caribbean islands of Guadeloupe and Martinique; and four in Europe. Some of these disease entities seem to be disappearing over time and therefore are probably triggered by unique environmental factors. By contrast, other types persist because they are exclusively genetically determined. Given the geographical clustering and potential overlap in biological and clinical features of these exceptionally interesting diseases, this Review provides a historical reference text and offers current perspectives on each of the 10 phenotypes of endemic parkinsonism. Knowledge obtained from the study of these disease entities supports the hypothesis that both genetic and environmental factors contribute to the development of neurodegenerative diseases, not only in endemic parkinsonism but also in general. At the same time, this understanding suggests useful directions for further research in this area.

The Pesticide Chlordecone Promotes Parkinsonism-like Neurodegeneration with Tau Lesions in Midbrain Cultures and C. elegans Worms.

Chlordecone (CLD) is an organochlorine pesticide (OCP) that is currently banned but still contaminates ecosystems in the French Caribbean. Because OCPs are known to increase the risk of Parkinson's disease (PD), we tested whether chronic low-level intoxication with CLD could reproduce certain key characteristics of Parkinsonism-like neurodegeneration. For that, we used culture systems of mouse midbrain dopamine (DA) neurons and glial cells, together with the nematode C. elegans as an in vivo model organism. We established that CLD kills cultured DA neurons in a concentration- and time-dependent manner while exerting no direct proinflammatory effects on glial cells. DA cell loss was not impacted by the degree of maturation of the culture. The use of fluorogenic probes revealed that CLD neurotoxicity was the consequence of oxidative stress-mediated insults and mitochondrial disturbances. In C. elegans worms, CLD exposure caused a progressive loss of DA neurons associated with locomotor deficits secondary to alterations in food perception. L-DOPA, a molecule used for PD treatment, corrected these deficits. Cholinergic and serotoninergic neuronal cells were also affected by CLD in C. elegans, although to a lesser extent than DA neurons. Noticeably, CLD also promoted the phosphorylation of the aggregation-prone protein tau (but not of α-synuclein) both in midbrain cell cultures and in a transgenic C. elegans strain expressing a human form of tau in neurons. In summary, our data suggest that CLD is more likely to promote atypical forms of Parkinsonism characterized by tau pathology than classical synucleinopathy-associated PD.

Brain dysfunction in gait disorders of Caribbean atypical Parkinsonism and progressive supranuclear palsy patients: A comparative study.

INTRODUCTION: Gait disorders and falls occur early in progressive supranuclear palsy (PSP-RS) and Caribbean atypical parkinsonism (Caribbean AP). However, the link between these signs and brain lesions has never been explored in these patient populations. Here, we investigate and compare the imaging factors that relate to gait and balance disorders in Caribbean AP and PSP-RS patients. METHODS: We assessed gait and balance using clinical scales and gait recordings in 16 Caribbean AP and 15 PSP-RS patients and 17 age-matched controls. We measured the grey and white matter brain volumes on 3 T brain MRI images. We performed a principal component analysis (PCA) including all the data to determine differences and similarities between groups, and explore the relationship between gait disorders and brain volumes. RESULTS: Both Caribbean AP patients and PSP-RS have marked gait and balance disorders with similar severity. In both groups, gait and balance disorders were found to be most strongly related to structural changes in the lateral cerebellum, caudate nucleus, and fronto-parietal areas. In Caribbean AP patients, gait disorders were also related to additional changes in the cortex, including frontal, insular, temporal and cuneus lobes, whereas in PSP-RS patients, additional white matter changes involved the mesencephalon and parahippocampal gyrus. CONCLUSION: Gait and balance disorders in Caribbean AP patients are mainly related to dysfunction of cortical brain areas involved in visuo-sensorimotor processing and self-awareness, whereas these signs mainly result from premotor-brainstem-cerebellar network dysfunction in PSP-RS patients, brain areas involved in initiation and maintenance of locomotor pattern and postural adaptation.

Annonaceae Consumption Worsens Disease Severity and Cognitive Deficits in Degenerative Parkinsonism.

BACKGROUND: High consumption of Annona muricata fruit has been previously identified as a risk factor for atypical parkinsonism in the French Caribbean islands. OBJECTIVE: We tested whether consumption of Annonaceae products could worsen the clinical phenotype of patients with any form of degenerative parkinsonism. METHODS: We analyzed neurological data from 180 Caribbean parkinsonian patients and specifically looked for dose effects of lifelong, cumulative Annonaceae consumption on cognitive performance. Using unsupervised clustering, we identified one cluster with mild/moderate symptoms (N = 102) and one with severe symptoms including cognitive impairment (N = 78). RESULTS: We showed that even low cumulative consumption of fruits/juices (>0.2 fruit-years) or any consumption of herbal tea from Annonaceae worsen disease severity and cognitive deficits in degenerative parkinsonism including Parkinson's disease (OR fruits-juices: 3.76 [95% CI: 1.13-15.18]; OR herbal tea: 2.91 [95% CI: 1.34-6.56]). CONCLUSION: We suggest that more restrictive public health preventive recommendations should be made regarding the consumption of Annonaceae products. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Impact of Smoking on Functional Prognosis after Ischemic Stroke according to Deprivation: A Prospective Cohort Study.

BACKGROUND: Smoking influence on poststroke prognosis remains controversial. These conflicting results could be due to some residual confounding factors not fully considered in previous studies, including social deprivation. This study aimed to assess the joint impact of deprivation and smoking on functional outcomes after ischemic stroke. METHODS: Between 2011 and 2014, 1,573 patients with a first-ever stroke were prospectively included in the French multicenter INDIA ("Inegalites sociales et pronostic des accidents vasculaires cerebraux à Dijon et Antilles-Guyane") cohort study. Patients with ischemic stroke and available data on smoking, deprivation, and outcome were considered for the analysis (n = 1,242). Deprivation was assessed using the EPICES "Evaluation de la Précarité et des Inégalites de santé dans les Centres d'Examen de Santé" score. Primary outcome was functional outcome assessed with the modified Rankin Scale (mRS) score at 12 months. Association between smoking and moderate to severe disability (mRS score ≥3) was evaluated with logistic regression model. Interactions between smoking and deprivation were tested. RESULTS: Smokers (n = 189, 15.2%) were younger and more often deprived (EPICES score ≥30.17) than nonsmokers. A significant interaction was found between smoking status and deprivation on disability (p = 0.003). In nondeprived patients, the odds of moderate to severe disability at 12 months were twice as high in smokers as in nonsmokers (adjusted OR = 2.08, 95% CI: 1.04-4.18). This association was not observed in deprived patients (adjusted OR = 0.89, 95% CI: 0.49-1.61). CONCLUSION: The effect of smoking on functional prognosis after ischemic stroke varied according to deprivation status, with poorer outcomes observed in nondeprived patients.

The microbiome-nose-brain axis in health and disease.

Growing evidence implicates the bacterial populations in the nose as an important factor for personal and global health. Here, we provide a brief overview of the nasal microbiome and speculate on its potential roles in olfactory processing and neurodegeneration, with a particular focus on Parkinson's disease (PD).

Olfactory outcomes in Zika virus-associated Guillain-Barré syndrome.

BACKGROUND AND PURPOSE: Zika virus (ZIKV) infection has been associated with Guillain-Barré syndrome (GBS). However, little is known about the consequence of ZIKV infection on olfaction in humans. METHODS: Immediately before the COVID-19 outbreak, we prospectively investigated the olfactory capacities of 19 patients with ZIKV-associated GBS from the French West Indies and compared them to nine controls from the same population, with GBS of similar severity but independent of ZIKV infection. To provide further evidence that ZIKV infection induces smell alteration, we investigated the consequences of ZIKV infection on olfactory abilities using a mouse model. RESULTS: Patients with GBS-ZIKA+ had poorer olfactory function than GBS-non-ZIKA, even 1-2 years after the acute phase. The proportion of patients with hyposmia was significantly higher in the GBS-ZIKA+ than in the GBS-non-ZIKA group (68.4% vs. 22.2%, p = 0.042). These deficits were characterized by lower threshold and identification scores and were independent from GBS severity. Additionally, ZIKV infection was found to impair olfaction in immunodeficient mice infected with ZIKV. High viral load was observed in their olfactory system and downstream brain structures. ZIKV promoted both cellular damage in the olfactory neuroepithelium and protracted inflammation of the olfactory bulb, likely accounting for smell alteration. CONCLUSIONS: Patients with ZIKV-related GBS had poorer long-term olfactory function than patients with GBS-non-ZIKA, and ZIKV-infected mice are hyposmic. These observations suggest that ZIKV belongs on the list of viruses affecting the olfactory system. Clinical evaluation of the olfactory system should be considered for ZIKV-infected patients.

Treatable Hyperkinetic Movement Disorders Not to Be Missed.

Hyperkinetic movement disorders are characterized by the presence of abnormal involuntary movements, comprising most notably dystonia, chorea, myoclonus, and tremor. Possible causes are numerous, including autoimmune disorders, infections of the central nervous system, metabolic disturbances, genetic diseases, drug-related causes and functional disorders, making the diagnostic process difficult for clinicians. Some diagnoses may be delayed without serious consequences, but diagnosis delays may prove detrimental in treatable disorders, ranging from functional disabilities, as in dopa-responsive dystonia, to death, as in Whipple's disease. In this review, we focus on treatable disorders that may present with prominent hyperkinetic movement disorders.

Doxycycline inhibits α-synuclein-associated pathologies in vitro and in vivo.

Parkinson's disease (PD) and dementia with Lewy bodies (DLB) are neurodegenerative disorders characterized by the misfolding and aggregation of alpha-synuclein (aSyn). Doxycycline, a tetracyclic antibiotic shows neuroprotective effects, initially proposed to be due to its anti-inflammatory properties. More recently, an additional mechanism by which doxycycline may exert its neuroprotective effects has been proposed as it has been shown that it inhibits amyloid aggregation. Here, we studied the effects of doxycycline on aSyn aggregation in vivo, in vitro and in a cell free system using real-time quaking induced conversion (RT-QuiC). Using H4, SH-SY5Y and HEK293 cells, we found that doxycycline decreases the number and size of aSyn aggregates in cells. In addition, doxycycline inhibits the aggregation and seeding of recombinant aSyn, and attenuates the production of mitochondrial-derived reactive oxygen species. Finally, we found that doxycycline induces a cellular redistribution of aggregates in a C.elegans animal model of PD, an effect that is associated with a recovery of dopaminergic function. In summary, we provide strong evidence that doxycycline treatment may be an effective strategy against synucleinopathies.

Acute cerebellar ataxia and myoclonus with or without opsoclonus: a para-infectious syndrome associated with COVID-19.

BACKGROUND AND PURPOSE: Patients with COVID-19 can have central or peripheral neurological manifestations. METHODS: The cases of two patients with acute cerebellar ataxia and myoclonus associated with COVID-19 are reported (with Video S1) and five previously reported patients are discussed. RESULTS: Acute cerebellar ataxia and myoclonus started between 10 days and 6 weeks after the first manifestations of COVID-19. Opsoclonus or ocular flutter was present in four patients. Patients were treated with intravenous immunoglobulins and/or steroids except for one patient, resulting in a striking improvement within a week. CONCLUSION: Acute cerebellar ataxia and myoclonus with or without opsoclonus belongs to the wide spectrum of neurological manifestations associated with COVID-19. It is important to recognize this possible manifestation since early treatment allows for rapid recovery.

Social deprivation and 1-year survival after stroke: a prospective cohort study.

BACKGROUND: Social deprivation may have a deleterious influence on post-stroke outcomes, but available data in the literature are mixed. AIM: The aim of this cohort study was to evaluate the impact of social deprivation on 1-year survival in patients with first-ever stroke. METHODS: Social deprivation was assessed at individual level with the EPICES score, a validated multidimensional questionnaire, in 1312 patients with ischemic stroke and 228 patients with spontaneous intracerebral hemorrhage, who were prospectively enrolled in six French study centers. Baseline characteristics including stroke severity and pre-stroke functional status were collected. Multivariable Cox models were generated to evaluate the associations between social deprivation and survival at 12 months in ischemic stroke and intracerebral hemorrhage separately. RESULTS: A total of 819 patients (53.2%) were socially deprived (EPICES score ≥ 30.17). In ischemic stroke, mortality at 12 months was higher in deprived than in non-deprived patients (16% vs. 11%, p = 0.006). In multivariable analyses, there was no association between deprivation and death occurring within the first 90 days following ischemic stroke (adjusted hazard ratio [aHR] 0.81, 95% CI 0.54-1.22, p = 0.32). In contrast, an excess in mortality was observed between 90 days and 12 months in deprived compared with non-deprived patients (aHR 1.97, 95% CI 1.14-3.42, p = 0.016). In patients with intracerebral hemorrhage, mortality at 12 months did not significantly differ according to deprivation status. CONCLUSIONS: Social deprivation was associated with delayed mortality in ischemic stroke patients only and, although the exact underlying mechanisms are still to be identified, our findings suggest that deprived patients in particular may benefit from an optimization of post-stroke care.

Neurologic manifestations associated with COVID-19: a multicentre registry.

OBJECTIVES: To provide an overview of the spectrum, characteristics and outcomes of neurologic manifestations associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. METHODS: We conducted a single-centre retrospective study during the French coronavirus disease 2019 (COVID-19) epidemic in March-April 2020. All COVID-19 patients with de novo neurologic manifestations were eligible. RESULTS: We included 222 COVID-19 patients with neurologic manifestations from 46 centres in France. Median (interquartile range, IQR) age was 65 (53-72) years and 136 patients (61.3%) were male. COVID-19 was severe or critical in 102 patients (45.2%). The most common neurologic diseases were COVID-19-associated encephalopathy (67/222, 30.2%), acute ischaemic cerebrovascular syndrome (57/222, 25.7%), encephalitis (21/222, 9.5%) and Guillain-Barré syndrome (15/222, 6.8%). Neurologic manifestations appeared after the first COVID-19 symptoms with a median (IQR) delay of 6 (3-8) days in COVID-19-associated encephalopathy, 7 (5-10) days in encephalitis, 12 (7-18) days in acute ischaemic cerebrovascular syndrome and 18 (15-28) days in Guillain-Barré syndrome. Brain imaging was performed in 192 patients (86.5%), including 157 magnetic resonance imaging (70.7%). Among patients with acute ischaemic cerebrovascular syndrome, 13 (22.8%) of 57 had multiterritory ischaemic strokes, with large vessel thrombosis in 16 (28.1%) of 57. Brain magnetic resonance imaging of encephalitis patients showed heterogeneous acute nonvascular lesions in 14 (66.7%) of 21. Cerebrospinal fluid of 97 patients (43.7%) was analysed, with pleocytosis found in 18 patients (18.6%) and a positive SARS-CoV-2 PCR result in two patients with encephalitis. The median (IQR) follow-up was 24 (17-34) days with a high short-term mortality rate (28/222, 12.6%). CONCLUSIONS: Clinical spectrum and outcomes of neurologic manifestations associated with SARS-CoV-2 infection were broad and heterogeneous, suggesting different underlying pathogenic processes.

Neurocognitive impacts of arbovirus infections.

Arthropod-borne viruses or arbovirus, are most commonly associated with acute infections, resulting on various symptoms ranging from mild fever to more severe disorders such as hemorrhagic fever. Moreover, some arboviral infections can be associated with important neuroinflammation that can trigger neurological disorders including encephalitis, paralysis, ophthalmological impairments, or developmental defects, which in some cases, can lead to long-term defects of the central nervous system (CNS). This is well illustrated in Zika virus-associated congenital brain malformations but also in West Nile virus-induced synaptic dysfunctions that can last well beyond infection and lead to cognitive deficits. Here, we summarize clinical and mechanistic data reporting on cognitive disturbances triggered by arboviral infections, which may highlight growing public health issues spanning the five continents.

Social deprivation among socio-economic contrasted french areas: Using item response theory analysis to assess differential item functioning of the EPICES questionnaire in stroke patients.

BACKGROUND: Multiple approaches have been proposed to measure low socio-economic status. In France the concept of precariousness, akin to social deprivation, was developed and is widely used. EPICES is a short questionnaire that was developed to measure this concept. This study aimed to evaluate Differential Item Functioning (DIF) in the EPICES questionnaire between contrasted areas: mainland France, French West Indies (FWI) and French Guiana (FG). METHODS: The population was taken from the INDIA study, which aimed to evaluate the impact of social inequalities on stroke characteristics and prognosis. Eligible people were patients referred to neurology or emergency departments for a suspicion of stroke. We assessed the DIF using hybrid ordinal logistic regression method, derived from item response theory. RESULTS: We analysed 1 553 stroke patients, including 768 from FWI (49.5%), 289 from FG (18.6%) and 496 from mainland (31.9%). We identified five items with a moderate to large DIF in area comparisons: "meeting with a social worker", "complementary health insurance", "home-owning", "financial difficulties" and "sport activities". Correlation between EPICES score and the latent variable was strong (r = 0.84). CONCLUSION: This is the first attempt to assess the DIF of the EPICES score between different French populations. We found several items with DIF, which can be explained by individual interpretation or local context. However, the DIFs did not lead to a large difference between the latent variable and the EPICES score, which indicates that it can be used to assess precariousness and social deprivation between contrasted areas.

Chikungunya, a Risk Factor for Guillain-Barré Syndrome.

In a matched case-control study where 24 cases developed Guillain-Barré syndrome (GBS) during the 2014 chikungunya outbreak in the French West Indies and 72 controls were blood donors during the same period, chikungunya infection was a risk factor for GBS (odds ratio, 8.3; 95% confidence interval, 2.3-29.7; P = .001).

Long-term outcome in neuroZika: When biological diagnosis matters.

OBJECTIVE: To characterize the full spectrum, relative frequency, and prognosis of the neurologic manifestations in Zika virus (ZIKV) postnatal infection. METHODS: We conducted an observational study in consecutive ZIKV-infected patients presenting with neurologic manifestations during the French West Indies 2016 outbreak. RESULTS: Eighty-seven patients, including 6 children, were enrolled. Ninety-five percent of all cases required hospitalization. Guillain-Barré syndrome was the most frequent manifestation (46.0%) followed by encephalitis or encephalomyelitis (20.7%), isolated single or multiple cranial nerve palsies (9.2%), other peripheral manifestations (6.9%), and stroke (1.1%). Fourteen patients (16.1%), including one child, developed a mixed disorder involving both the central and peripheral nervous system. Mechanical ventilation was required in 21 cases, all of whom had ZIKV RNA in at least one biological fluid. Two adult patients died due to neuroZika. Clinical follow-up (median 14 months; interquartile range, 13-17 months) was available for 76 patients. Residual disability (modified Rankin Scale score ≥2) was identified in 19 (25.0%) patients; in 6 cases (7.9%), disability was severe (modified Rankin Scale score ≥4). Among patients with ZIKV RNA detected in one biological fluid, the risk of residual disability or death was higher (odds ratio 9.19; confidence interval 1.12-75.22; p = 0.039). CONCLUSIONS: NeuroZika spectrum represents a heterogeneous group of clinical neurologic manifestations. During an outbreak, clinicians should consider neuroZika in patients presenting with cranial nerve palsies and a mixed neurologic disorder. Long-term sequelae are frequent in NeuroZika. ZIKV reverse-transcription PCR status at admission can inform prognosis and should therefore be taken into consideration in the management of hospitalized patients.

Telerehabilitation for Stroke Survivors: Systematic Review and Meta-Analysis.

BACKGROUND: Telerehabilitation is an emerging technology through which medical rehabilitation care can be provided from a distance. OBJECTIVE: This systematic review and meta-analysis aims to investigate the efficacy of telerehabilitation in poststroke patients. METHODS: Eligible randomized controlled trials (RCTs) were identified by searching MEDLINE, Cochrane Central, and Web of Science databases. Continuous data were extracted for relevant outcomes and analyzed using the RevMan software as the standardized mean difference (SMD) and 95% CI in a fixed-effect meta-analysis model. RESULTS: We included 15 studies (1339 patients) in our systematic review, while only 12 were included in the pooled analysis. The combined effect estimate showed no significant differences between the telerehabilitation and control groups in terms of the Barthel Index (SMD -0.05, 95% CI -0.18 to 0.08), Berg Balance Scale (SMD -0.04, 95% CI -0.34 to 0.26), Fugl-Meyer Upper Extremity (SMD 0.50, 95% CI -0.09 to 1.09), and Stroke Impact Scale (mobility subscale; SMD 0.18, 95% CI -0.13 to 0.48]) scores. Moreover, the majority of included studies showed that both groups were comparable in terms of health-related quality of life (of stroke survivors), Caregiver Strain Index, and patients' satisfaction with care. One study showed that the cost of telerehabilitation was lower than usual care by US $867. CONCLUSIONS: Telerehabilitation can be a suitable alternative to usual rehabilitation care in poststroke patients, especially in remote or underserved areas. Larger studies are needed to evaluate the health-related quality of life and cost-effectiveness with the ongoing improvements in telerehabilitation networks.