Quantitative brainstem and spinal MRI in amyotrophic lateral sclerosis: implications for predicting noninvasive ventilation needs

BACKGROUND

Respiratory complications resulting from motor neurons degeneration are the primary cause of death in amyotrophic lateral sclerosis (ALS). Predicting the need for non-invasive ventilation (NIV) in ALS is important for advance care planning and clinical trial design. The aim of this study was to assess the potential of quantitative MRI at the brainstem and spinal cord levels to predict the need for NIV during the first six months after diagnosis.

METHODS

Forty-one ALS patients underwent MRI and spirometry shortly after diagnosis. The need for NIV was monitored according to French health guidelines for 6 months. The performance of four regression models based on: clinical variables, brainstem structures volumes, cervical spinal measurements, and combined variables were compared to predict the need for NIV within this period.

RESULTS

Both the clinical model (R2 = 0.28, AUC = 0.85, AICc = 42.67, BIC = 49.8) and the brainstem structures' volumes model (R2 = 0.30, AUC = 0.85, AICc = 40.13, BIC = 46.99) demonstrated good predictive performance. In addition, cervical spinal cord measurements model similar performance (R2 = 0.338, AUC = 0.87, AICc = 37.99, BIC = 44.49). Notably, the combined model incorporating predictors from all three models yielded the best performance (R2 = 0.60, AUC = 0.959, AICc = 36.38, BIC = 44.8). These findings are supported by observed positive correlations between brainstem volumes, cervical (C4/C7) cross-sectional area, and spirometry-measured lung volumes.

CONCLUSIONS

Our study shows that brainstem volumes and spinal cord area are promising measures to predict respiratory intervention needs in ALS.

Cardiovascular benefits of SGLT2 inhibitors and GLP-1 receptor agonists through effects on mitochondrial function and oxidative stress

Overloaded glucose levels in several metabolic diseases such as type 2 diabetes (T2D) can lead to mitochondrial dysfunction and enhanced production of reactive oxygen species (ROS). Oxidative stress and altered mitochondrial homeostasis, particularly in the cardiovascular system, contribute to the development of chronic comorbidities of diabetes. Diabetes-associated hyperglycemia and dyslipidemia can directly damage vascular vessels and lead to coronary artery disease or stroke, and indirectly damage other organs and lead to kidney dysfunction, known as diabetic nephropathy. The new diabetes treatments include Na+-glucose cotransporter 2 inhibitors (iSGLT2) and glucagon-like 1 peptide receptor agonists (GLP-1RA), among others. The iSGLT2 are oral anti-diabetic drugs, whereas GLP-1RA are preferably administered through subcutaneous injection, even though GLP-1RA oral formulations have recently become available. Both therapies are known to improve both carbohydrate and lipid metabolism, as well as to improve cardiovascular and cardiorenal outcomes in diabetic patients. In this review, we present an overview of current knowledge on the relationship between oxidative stress, mitochondrial dysfunction, and cardiovascular therapeutic benefits of iSGLT2 and GLP-1RA. We explore the benefits, limits and common features of the treatments and remark how both are an interesting target in the prevention of obesity, T2D and cardiovascular diseases, and emphasize the lack of a complete understanding of the underlying mechanism of action.

Crosschecking the subjective everyday Parkinson's experience among patients and their caregiving spouses: French versions of the Belastungsfragebogen Parkinson Kurzversion (Bela-P-k and Bela-A-k)

BACKGROUND

Parkinson's disease (PD) affects all dimensions of the patient's and the caregiver's daily life. There are two questionnaires in German, Bela-A-k (for caregivers) and Bela-P-k (for PD patients), that can be used to assess the PD-related psychosocial burden in a dyad. The patient's and the caregiver's perspective of living with PD can be crosschecked. Four dimensions are explored: physical performance, emotional load, social relationships, and couple/family life.

OBJECTIVES

The purpose of the study was to translate these questionnaires into French and to test them among patients and caregivers.

METHODS

The questionnaires were translated from German into French by forward and backward translation, followed by a cultural crosscheck. Participants were invited to test the consensual French version in its online administered version created via Lime Survey® software. Participants filled out the questionnaires twice (five-day interval) according to the test-retest method. Data analysis was performed with SPSS software.

RESULTS

Thirty dyads were recruited and eighteen completed the study. Bela-A-K showed strong temporal stability, though it was weak for the social relationships dimension. Bela-P-k showed strong internal consistency, but significant test-retest differences for ten items due to day-by-day changes in patient status.

CONCLUSIONS

The questionnaires are useful and reliable for dyad-centered follow-up in case of PD. Some items of the Bela-P-k were simplified to improve its temporal stability, considering the patient's changing status through the day. The items concerning social relationships were adjusted for the Bela-A-k.

Comparison of spinal magnetic resonance imaging and classical clinical factors in predicting motor capacity in amyotrophic lateral sclerosis

BACKGROUND

Motor capacity is crucial in amyotrophic lateral sclerosis (ALS) clinical trial design and patient care. However, few studies have explored the potential of multimodal MRI to predict motor capacity in ALS. This study aims to evaluate the predictive value of cervical spinal cord MRI parameters for motor capacity in ALS compared to clinical prognostic factors.

METHODS

Spinal multimodal MRI was performed shortly after diagnosis in 41 ALS patients and 12 healthy participants as part of a prospective multicenter cohort study, the PULSE study (NCT00002013-A00969-36). Motor capacity was assessed using ALSFRS-R scores. Multiple stepwise linear regression models were constructed to predict motor capacity at 3 and 6 months from diagnosis, based on clinical variables, structural MRI measurements, including spinal cord cross-sectional area (CSA), anterior-posterior, and left-to-right cross-section diameters at vertebral levels from C1 to T4, and diffusion parameters in the lateral corticospinal tracts (LCSTs) and dorsal columns.

RESULTS

Structural MRI measurements were significantly correlated with the ALSFRS-R score and its sub-scores. And as early as 3 months from diagnosis, structural MRI measurements fit the best multiple linear regression model to predict the total ALSFRS-R (R² = 0.70, p value = 0.0001) and arm sub-score (R² = 0.69, p value = 0.0002), and combined with DTI metric in the LCST and clinical factors fit the best multiple linear regression model to predict leg sub-score (R² = 0.73, p value = 0.0002).

CONCLUSIONS

Spinal multimodal MRI could be promising as a tool to enhance prognostic accuracy and serve as a motor function proxy in ALS.

Indication for molecular testing by multiplex ligation-dependent probe amplification in parkinsonism

BACKGROUND

The monogenic forms of Parkinson's disease represent less than 10% of familial cases and a still lower frequency of sporadic cases. However, guidelines to orient genetic testing are lacking. We aim to establish the interest of multiplex ligation-dependent probe amplification as a primary screening test and to propose clinical criteria to guide genetic diagnostic tests for patients with suspected Mendelian Parkinson's disease.

METHODS

We recruited 567 patients with parkinsonism from 547 unrelated families and performed two multiplex ligation-dependent probe amplifications for each. We confirmed all pathogenic G2019S variants in the LRRK2 gene by Sanger sequencing and screened the PRKN gene for a second mutation in cases of one heterozygous structural variant in the PRKN gene.

RESULTS

The performance of multiplex ligation-dependent probe amplifications was 51/567 (9%) for the entire cohort and included 27 (4.8%) LRRK2 G2019S mutations, 19 (3.4%) PRKN mutations, and 5 (0.9%) SNCA locus duplications. The variables significantly associated with a positive test in the total cohort were North African ancestry (p < 0.0001), female sex (p = 0.004), and younger age at onset (p < 0.0008).

CONCLUSIONS

Retrospective analysis allowed us to refine our indication criteria: (i) North African ancestry, (ii) an age at onset < 40, or (iii) a familial history of parkinsonism with at least one affected first-degree relative. Our study highlights the interest of MLPA testing for other parkinsonisms cases with a family history, especially for patients with dementia with Lewy bodies or a multiple system atrophy-like phenotype.

SARS-CoV-2-related Multisystem Inflammatory Syndrome in Adult complicated by myocarditis and cardiogenic shock

Multisystem Inflammatory Syndrome in Adult (MIS-A) is a rare COVID-19 complication, presenting as fever with laboratory evidence of inflammation, severe illness requiring hospitalization and multisystem organ involvement. We report on a 25-year-old man presenting with fever, rash, abdominal pain, diarrhoea and vomiting following prior asymptomatic COVID-19 infection. He developed refractory shock and type 1 respiratory insufficiency requiring mechanical ventilation. Diagnostic testing revealed significant inflammation, anemia, thrombocytopenia, acute kidney injury, hepatosplenomegaly, colitis, lymphadenopathy and myocarditis necessitating inotropy. Ventilatory, vasopressor and inotropic support was weaned following pulse corticosteroids and intravenous immunoglobulins. Heart failure therapy was started. Short-term follow-up shows resolution of inflammation and cardiac dysfunction.

Use of levodopa-carbidopa intestinal gel to treat patients with multiple system atrophy

BACKGROUND

Levodopa-carbidopa intestinal gel (LCIG) is an effective treatment for late-stage Parkinson's disease (PD) but had not been evaluated in levodopa-responsive patients with the parkinsonian variant of multiple system atrophy (MSA-P) and motor fluctuations. We aimed to assess the safety of LCIG in MSA-P patients.

METHODS

In a retrospective, single-center study, we analyzed clinical and treatment-related data for all patients with MSA-P or PD treated with LCIG between December 2004 and November 2017. Adverse events (AEs) were classified into three classes: AEs related to gastrointestinal effects or to the PEG-J procedure, AEs related to the device, and AEs related to the pharmacological effect of LCIG.

RESULTS

7 MSA-P and 63 PD patients had been treated with LCIG for a median [interquartile range] period of 31 [16;43] and 19 [8;45] months, respectively. There were no significant intergroup differences in safety. Enteral nutrition was introduced at the same time as LCIG treatment in 4 (57%) MSA-P patients. In the MSA-P and PD groups, LCIG was associated with a better Global Clinical Impression score and discontinuation of oral anti-parkinsonian drugs (in 43% and 27% of cases, respectively).

CONCLUSIONS

LCIG treatment is feasible in MSA-P patients with severe motor complications. The safety profile is similar to that seen in PD.

MRI of the cervical spinal cord predicts respiratory dysfunction in ALS

For patients with amyotrophic lateral sclerosis (ALS), the primary therapeutic goal is to minimize morbidity. Non-invasive ventilation improves survival. We aim to assess whether Magnetic Resonance Imaging (MRI) of the cervical spinal cord predicts the progression of respiratory disorders in ALS. Brain and spinal MRI was repeatedly performed in the SOD1^G86R mouse model, in 40 patients and in healthy controls. Atrophy, iron overload, white matter diffusivity and neuronal loss were assessed. In Superoxide Dismutase-1 (SOD1) mice, iron accumulation appeared in the cervical spinal cord at symptom onset but disappeared with disease progression (after the onset of atrophy). In ALS patients, the volumes of the motor cortex and the medulla oblongata were already abnormally low at the time of diagnosis. Baseline diffusivity in the internal capsule was predictive of functional handicap. The decrease in cervical spinal cord volume from diagnosis to 3 months was predictive of the change in slow vital capacity at 12 months. MRI revealed marked abnormalities at the time of ALS diagnosis. Early atrophy of the cervical spinal cord may predict the progression of respiratory disorders, and so may be of value in patient care and as a primary endpoint in pilot neuroprotection studies.

Ethical considerations and palliative care in patients with amyotrophic lateral sclerosis: A review

Amyotrophic lateral sclerosis (ALS) is not a curable disease, but it is treatable. By definition, much of the care provided to ALS patients is palliative, even though active life-sustaining strategies are available to prolong survival. Healthcare professionals must develop communication skills that help patients cope with the inexorable progression of the disease and the inevitability of death. Symptomatic treatments as well as respiratory insufficiency and nutritional life-sustaining therapies must be regularly evaluated as the disease progresses, without losing sight of the burden placed on the patient's non-professional caregivers. The decision-making process regarding tracheostomy with invasive ventilation (TIV) is of greater complexity. Providing full information is crucial. Several long interviews are necessary to explain, discuss and allow assimilation of the information. Also, physicians should be careful not to focus exclusively on the biomedical aspects of disease, as ALS patients generally welcome the opportunity to discuss end-of-life issues with their physicians. Psychological factors, education level and cognitive status (especially the level of executive dysfunction) have a major influence on their decisions. However, as many patients do not complete advance directives with regard to TIV, advance care planning may instead be suggested in anticipation of emergency interventions. This should be discussed by healthcare professionals and the patient, and based on the wishes of the patient and caregiver(s), and communicated to all healthcare professionals. Many healthcare professionals are involved in the management of an ALS patient: they include not only those at ALS centers who provide diagnosis, follow-up and treatment initiation (particularly for respiratory and nutritional care), but also the medical and social care networks involved in disability support and home care. Specialist palliative care teams can work in partnership with ALS centers early in the course of the disease, with the center coordinating information-sharing and collaborative discussions.

Continuous cerebroventricular administration of dopamine: A new treatment for severe dyskinesia in Parkinson's disease?

In Parkinson's disease (PD) depletion of dopamine in the nigro-striatal pathway is a main pathological hallmark that requires continuous and focal restoration. Current predominant treatment with intermittent oral administration of its precursor, Levodopa (l-dopa), remains the gold standard but pharmacological drawbacks trigger motor fluctuations and dyskinesia. Continuous intracerebroventricular (i.c.v.) administration of dopamine previously failed as a therapy because of an inability to resolve the accelerated dopamine oxidation and tachyphylaxia. We aim to overcome prior challenges by demonstrating treatment feasibility and efficacy of continuous i.c.v. of dopamine close to the striatum. Dopamine prepared either anaerobically (A-dopamine) or aerobically (O-dopamine) in the presence or absence of a conservator (sodium metabisulfite, SMBS) was assessed upon acute MPTP and chronic 6-OHDA lesioning and compared to peripheral l-dopa treatment. A-dopamine restored motor function and induced a dose dependent increase of nigro-striatal tyrosine hydroxylase positive neurons in mice after 7days of MPTP insult that was not evident with either O-dopamine or l-dopa. In the 6-OHDA rat model, continuous circadian i.c.v. injection of A-dopamine over 30days also improved motor activity without occurrence of tachyphylaxia. This safety profile was highly favorable as A-dopamine did not induce dyskinesia or behavioral sensitization as observed with peripheral l-dopa treatment. Indicative of a new therapeutic strategy for patients suffering from l-dopa related complications with dyskinesia, continuous i.c.v. of A-dopamine has greater efficacy in mediating motor impairment over a large therapeutic index without inducing dyskinesia and tachyphylaxia.

The value of magnetic resonance imaging as a biomarker for amyotrophic lateral sclerosis: a systematic review

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a fatal, rapidly progressive neurodegenerative disease that mainly affects the motor system. A number of potentially neuroprotective and neurorestorative disease-modifying drugs are currently in clinical development. At present, the evaluation of a drug's clinical efficacy in ALS is based on the ALS Functional Rating Scale Revised, motor tests and survival. However, these endpoints are general, variable and late-stage measures of the ALS disease process and thus require the long-term assessment of large cohorts. Hence, there is a need for more sensitive radiological biomarkers. Various sequences for magnetic resonance imaging (MRI) of the brain and spinal cord have may have value as surrogate biomarkers for use in future clinical trials. Here, we review the MRI findings in ALS, their clinical correlations, and their limitations and potential role as biomarkers.

METHODS

The PubMed database was screened to identify studies using MRI in ALS. We included general MRI studies with a control group and an ALS group and longitudinal studies even if a control group was lacking.

RESULTS

A total of 116 studies were analysed with MRI data and clinical correlations. The most disease-sensitive MRI patterns are in motor regions but the brain is more broadly affected.

CONCLUSION

Despite the existing MRI biomarkers, there is a need for large cohorts with long term MRI and clinical follow-up. MRI assessment could be improved by standardized MRI protocols with multicentre studies.

Powerhouse failure and oxidative damage in autosomal recessive spastic ataxia of Charlevoix-Saguenay

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a neurodegenerative disease due to mutations in SACS, which encodes sacsin, a protein localized on the mitochondrial surface and possibly involved in mitochondrial dynamics. In view of the possible mitochondrial involvement of sacsin, we investigated mitochondrial activity at functional and molecular level in skin fibroblasts obtained from ARSACS patients. We observed remarkable bioenergetic damage in ARSACS cells, as indicated by reduced basal, adenosine triphosphate (ATP)-linked and maximal mitochondrial respiration rate, and by reduced respiratory chain activities and mitochondrial ATP synthesis. These phenomena were associated with increased reactive oxygen species production and oxidative nuclear DNA damage. Our results suggest that loss of sacsin is associated with oxidative stress and mitochondrial dysfunction, and thus highlight a novel mechanism in the pathogenesis of ARSACS. The involvement of mitochondria and oxidative stress in disease pathogenesis has been described in a number of other neurodegenerative diseases. Therefore, on the basis of our findings, which suggest a potential therapeutic role for antioxidant agents, ARSACS seems to fall within a larger group of disorders.

Clinical implications of neuropharmacogenetics

INTRODUCTION

Pharmacogenetics aims to identify the underlying genetic factors participating in the variability of drug response. Indeed, genetic variability at the DNA or RNA levels can directly or indirectly modify the pharmacokinetic or the pharmacodynamic parameters of a drug. The ultimate aim of pharmacogenetics is to move towards a personalised medicine by predicting responders and non-responders, adjusting the dose of the treatment, and identifying individuals at risk of adverse drug effects.

METHODS

A literature research was performed in which we reviewed all pharmacogenetic studies in neurological disorders including neurodegenerative diseases, multiple sclerosis, stroke and epilepsy.

RESULTS

Several pharmacogenetic studies have been performed in neurology, bringing insights into the inter-individual drug response variability and in the pathophysiology of neurological diseases. The principal implications of these studies for the management of patients in clinical practice are discussed.

CONCLUSION/DISCUSSION

Although several genetic factors have been identified in the modification of drug response in neurological disorders, most of them have a marginal predictive effect at the single gene level, suggesting mutagenic interactions as well as other factors related to drug interaction and disease subtypes. Most pharmacogenetic studies deserve further replication in independent populations and, ideally, in pharmacogenetic clinical trials to demonstrate their relevance in clinical practice.

Comparative analysis of targeted metabolomics: dominance-based rough set approach versus orthogonal partial least square-discriminant analysis

BACKGROUND

Metabolomics is an emerging field that includes ascertaining a metabolic profile from a combination of small molecules, and which has health applications. Metabolomic methods are currently applied to discover diagnostic biomarkers and to identify pathophysiological pathways involved in pathology. However, metabolomic data are complex and are usually analyzed by statistical methods. Although the methods have been widely described, most have not been either standardized or validated. Data analysis is the foundation of a robust methodology, so new mathematical methods need to be developed to assess and complement current methods. We therefore applied, for the first time, the dominance-based rough set approach (DRSA) to metabolomics data; we also assessed the complementarity of this method with standard statistical methods. Some attributes were transformed in a way allowing us to discover global and local monotonic relationships between condition and decision attributes. We used previously published metabolomics data (18 variables) for amyotrophic lateral sclerosis (ALS) and non-ALS patients.

RESULTS

Principal Component Analysis (PCA) and Orthogonal Partial Least Square-Discriminant Analysis (OPLS-DA) allowed satisfactory discrimination (72.7%) between ALS and non-ALS patients. Some discriminant metabolites were identified: acetate, acetone, pyruvate and glutamine. The concentrations of acetate and pyruvate were also identified by univariate analysis as significantly different between ALS and non-ALS patients. DRSA correctly classified 68.7% of the cases and established rules involving some of the metabolites highlighted by OPLS-DA (acetate and acetone). Some rules identified potential biomarkers not revealed by OPLS-DA (beta-hydroxybutyrate). We also found a large number of common discriminating metabolites after Bayesian confirmation measures, particularly acetate, pyruvate, acetone and ascorbate, consistent with the pathophysiological pathways involved in ALS.

CONCLUSION

DRSA provides a complementary method for improving the predictive performance of the multivariate data analysis usually used in metabolomics. This method could help in the identification of metabolites involved in disease pathogenesis. Interestingly, these different strategies mostly identified the same metabolites as being discriminant. The selection of strong decision rules with high value of Bayesian confirmation provides useful information about relevant condition-decision relationships not otherwise revealed in metabolomics data.

Iron deposits in post-mortem brains of patients with neurodegenerative and cerebrovascular diseases: a semi-quantitative 7.0 T magnetic resonance imaging study

BACKGROUND AND PURPOSE

Accumulation of iron (Fe) is often detected in brains of people suffering from neurodegenerative diseases. However, no studies have compared the Fe load between these disease entities. The present study investigates by T2*-weighted gradient-echo 7.0 T magnetic resonance imaging (MRI) the Fe content in post-mortem brains with different neurodegenerative and cerebrovascular diseases.

METHODS

One hundred and fifty-two post-mortem brains, composed of 46 with Alzheimer's disease (AD), 37 with frontotemporal lobar degeneration (FTLD), 11 with amyotrophic lateral sclerosis, 13 with Lewy body disease, 14 with progressive supranuclear palsy, 16 with vascular dementia (VaD) and 15 controls without a brain disease, were examined. The Fe load was determined semi-quantitatively on T2*-weighted MRI serial brain sections in the claustrum, caudate nucleus, putamen, globus pallidus, thalamus, subthalamic nucleus, hippocampus, mamillary body, lateral geniculate body, red nucleus, substantia nigra and dentate nucleus. The disease diagnosis was made on subsequent neuropathological examination.

RESULTS

The Fe load was significantly increased in the claustrum, caudate nucleus and putamen of FTLD brains and to a lesser degree in the globus pallidus, thalamus and subthalamic nucleus. In the other neurodegenerative diseases no Fe accumulation was observed, except for a mild increase in the caudate nucleus of AD brains. In VaD brains no Fe increase was detected.

CONCLUSIONS

Only FTLD displays a significant Fe load, suggesting that impaired Fe homeostasis plays an important role in the pathogenesis of this heterogeneous disease entity.

[Continuous subcutaneous infusion of apomorphine in Parkinson's disease: retrospective analysis of a series of 81 patients]

BACKGROUND

Continuous subcutaneous infusion of apomorphine (CAI) has shown efficacy in the treatment of motor fluctuations but its place in the therapeutic arsenal remains poorly defined in terms of indication, acceptability and long-term tolerance. Indeed, few studies have been carried out with a follow-up greater than 12 months. The main objective was to assess the quality of life of Parkinson's disease (PD) patients treated with CAI. We also evaluate the effectiveness on the motor fluctuations, the long-term tolerance of this treatment with its causes of discontinuation and the treatment regimens used.

METHODS

We conducted a retrospective study of 81 PD patients treated with CAI between April 2003 and June 2012. Data were collected from medical records. A repeated measures analysis of variance by the linear mixed model was used (significance level: 5%).

RESULTS

In August 2012, 27/81 patients were still treated with CAI with a mean duration of 28 months, 46/81 discontinued CAI (9 precociously), and 8 were lost to view. We didn't show improvement in the quality of life nor efficacy of CAI on the UPDRS IV score (P=0.54) and dyskinesia score (P=0.95). The CGI score patient also reflects this result with a majority response suggesting no significant change with CAI. We observed relative good cognitive and psychiatric tolerance. Adverse events were frequent but often benign. The average (±SD) rate of apomorphine was 3.15±1.71 mg/h and the oral dopaminergic treatment was decreased by 37.8%.

DISCUSSION

The results are consistent with the literature except for the lack of efficiency on motor fluctuations which may be due to the use of too small doses of apomorphine. This seems to be a leading cause of discontinuation of CAI, especially when it is associated with side effects or important constraints. For better efficiency on motor fluctuations, we recommend the use of apomorphine at higher doses to obtain an optimal continuous dopaminergic stimulation.

Management of ischemic stroke in the hyperacute phase

Over the last 15 years, advances in acute ischemic stroke (AIS) management have led to a significant reduction in the morbidity and mortality related to this serious disease. This has resulted from progress in imaging technology, increased access to imaging procedures, enhanced coordination in stroke care from emergency departments to rehabilitation centers, development of organized inpatient stroke units, and to the widespread use of acute thrombolysis. Once the diagnosis of AIS is confirmed by neuroimaging, the etiological work up is conducted in parallel with therapeutic measures by stroke units. The intravenous administration of recombinant tissue plasminogen activator (rt-PA) remains the most beneficial intervention in emergency stroke management, but it must be administered within 4.5 hours following the onset of symptoms and only in eligible patients. Recently, several procedures for increasing the efficacy of arterial recanalization have emerged, including intra-arterial administration of thrombolytic agents, mechanical reopening techniques, development of new thrombolytic agents, protocol modifications that allow treatment beyond 4.5 hours or in individuals >80 years old, and remote patient evaluation via telemedicine. So far, no potentially neuroprotective drug has shown to improve outcome following stroke. In addition, pulmonary status, blood pressure, glucose, temperature, and cardiac function must be closely monitored in patients undergoing treatment for AIS. Complications such as cerebral edema, hemorrhagic transformation, seizure, infection, and venous thromboembolic disease worsen the prognosis, and must be prevented or treated. Like myocardial infarction, ischemic stroke should be considered as a treatable emergency. Widespread public education regarding stroke symptoms, novel treatments, and time constraints for effective therapy should increase the number of patients that present within the first hours after stroke. Since "time is brain," early presentation is key to transforming trial results into effective stroke therapies.

[Pharmacological hypotheses and therapeutic strategies for gait disorders in Parkinson's disease]

Gait disorders form part of the axial symptoms observed in Parkinson's disease (PD) and also represent a major source of therapeutic failure in the later stages of PD, with the appearance of freezing of gait (FOG) and falls. Double-blind clinical trials and, above all, clinical experience have demonstrated that l-DOPA is effective in reducing FOG. Dopaminergic agonists appear to be less effective than l-DOPA and lack formal proof of their efficacy. The enzyme inhibitors provide modest benefits, which need to be confirmed. Hence, these symptoms appear to be partially doparesistant and justify investigation of other major neurotransmission systems. Of the various drugs with partial noradrenergic activity, methylphenidate may improve FOG and attention disorders. Memantine has shown some value in improving motor symptoms and gait in fluctuating parkinsonian patients - possibly by reducing the effect of glutamatergic hyperactivation of the subthalamic nucleus on the pedunculopontine nucleus (PPN). The PPN's dense cholinergic innervation also suggests that cholinesterase inhibitors may be of use, although any benefits must be set against a potential aggravation of rest tremor. The many interactions between the serotoninergic and dopaminergic systems require the implementation of clinical studies on the complex motor impact of serotoninergic treatments, which may aggravate the parkinsonian syndrome while improving gait (as is the case with paroxetine and ritanserin). This review seeks to develop the various pathophysiological hypotheses prompted by the results of fundamental studies and pilot clinical trials, with a view to justifying the implementation of confirmatory, double-blind, placebo-controlled therapeutic trials.

[Mechanisms of deregulated response to hypoxia in sporadic amyotrophic lateral sclerosis: a clinical study]

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder of upper and lower motorneurons, leading to death in 3 to 5 years. Respiratory insufficiency and hypoxemia are closely linked during the clinical course of ALS. Chronic respiratory insufficiency and hypoxemia generally occur late in the disease course but rapid episodes of intermittent hypoxemia followed by reoxygenation can occur early and insidiously. Two pathways are involved in the response to hypoxemia: (i) hypoxia inducible factor-1 (HIF-1) and VEGF/HIF-2 and an erythropoietin (EPO) mediated pathway, in response to prolonged hypoxemia; and (ii) nuclear factor kappa-B (NFkappa-B) during acute hypoxemia followed by reoxygenation episodes, inducing inflammatory mediators: interleukin-6 (IL-6), TNF-alpha, cyclo oxygenase-2 (COX-2) and prostaglandin E-2 (PGE-2). Our aim was to specify the role of the different functional pathways of response to hypoxemia in sporadic ALS patients, compared with neurological controls and according to the level of hypoxemia. We report the results of several studies of hypoxemic and/or inflammatory mediators in the cerebrospinal fluid (CSF) from ALS patients, according to their respiratory status, showing a selective defect of HIF-1 mediated angiogenic factors (VEGF and angiogenin [ANG]) during chronic hypoxia in sporadic ALS patients, compared to hypoxemic neurological controls; contrasting with an early activation of the NFkappa-B pathway since the isolated desaturation stage (IL-6, TNF-alpha, PGE-2, angiopoietin-2) in the same cohort of sporadic ALS patients. All these results are consistent with a selective impairment of the HIF-1 pathway during chronic hypoxemia in ALS patients. Inflammatory mediators were strongly elevated, since the early stage of the disease until chronic hypoxemia, suggesting a compensatory mechanism.

Predictors of Success After a First Circumferential Pulmonary Vein Isolation For Atrial Fibrillation

Background: To identify and characterise pre-procedural and procedural parameters which predict maintenance of sinus rhythm after a first circumferential pulmonary vein isolation (CPVI) for recurrent atrial fibrillation (AF). Methods: 100 patients (54±10 yrs) undergoing CARTO-guided CPVI for symptomatic drug refractory, paroxysmal or shortstanding persistent AF were studied. The endpoint was complete electrical isolation within the encircled regions. 3D left atrial (LA) volume was measured by CARTO geometry. Follow-up examinations (symptoms, ECG, 24-hour ECG recording) were performed at 1 and 3 months and every 3 months thereafter. Results: After the first CPVI, 71 patients (71%) were free of AF without antiarrhythmic drug therapy (follow up:28±11 months). The only independent and significant predictors for freedom of AF after the first CPVI were duration of AF history and 3D LA volume (p<0.05). However, a significant overlap in durations of AF history and 3D LA volumes between failures and successes was observed. Conclusions: (1) Using the "circumferential pulmonary vein isolation" approach, the first catheter ablation leads to resolution of arrhythmia in ≈ 70% of symptomatic AF patients. (2) Independent predictors for freedom of AF after initial CPVI are duration of AF history and 3D LA volume. (3) Due to considerable overlap between failures and successes, these parameters can not be used to identify patients who should not undergo CPVI or in whom an additional ablation beyond CPVI is required. On the other hand, our results do suggest that an ablation strategy early in the course of AF disease can influence successful outcome.

Deficient "sensory" beta synchronization in Parkinson's disease

OBJECTIVE

Beta rhythm movement-related synchronization (beta synchronization) reflects motor cortex deactivation and sensory afference processing. In Parkinson's disease (PD), decreased beta synchronization after active movement reflects abnormal motor cortex idling and may be involved in the pathophysiology of akinesia. The objectives of the present study were to (i) compare event-related synchronization after active and passive movement and electrical nerve stimulation in PD patients and healthy, age-matched volunteers and (ii) evaluate the effect of levodopa.

METHODS

Using a 128-electrode EEG system, we studied beta synchronization after active and passive index finger movement and electrical median nerve stimulation in 13 patients and 12 control subjects. Patients were recorded before and after 150% of their usual morning dose of levodopa.

RESULTS

The peak beta synchronization magnitude in the contralateral primary sensorimotor (PSM) cortex was significantly lower in PD patients after active movement, passive movement and electrical median nerve stimulation, compared with controls. Levodopa partially reversed the drop in beta synchronization after active movement but not after passive movement or electrical median nerve stimulation.

DISCUSSION

If one considers that beta synchronization reflects sensory processing, our results suggest that integration of somaesthetic afferences in the PSM cortex is abnormal in PD during active and passive movement execution and after simple electrical median nerve stimulation.

SIGNIFICANCE

Better understanding of the mechanisms involved in the deficient beta synchronization observed here could prompt the development of new therapeutic approaches aimed at strengthening defective processes. The lack of full beta synchronization restoration by levodopa might be related to the involvement of non-dopaminergic pathways.

[Continuous dopaminergic stimulation by Duodopa in advanced Parkinson's disease: Efficacy and safety]

INTRODUCTION

When advanced Parkinson's disease (PD) patients experience motor complications (fluctuations and dyskinesias) despite standard oral treatment, two treatment options are available: deep brain stimulation and subcutaneous apomorphine infusion with respects of indications for each strategy. Continuous intraduodenal infusion of levodopa (Duodopa) via a gastrojejunal tube may be proposed at this stage of the disease and the study of indications and clinical results with Duodopa may develop this new therapeutic alternative.

PATIENTS AND METHODS

Seven patients with advanced PD (dementia for all and psychiatric disorders for some of them, axial signs) were treated with Duodopa. We evaluated neuropsychological functions, all UPDRS scales, gait and quality-of-life just before Duodopa onset and six months after treatment end. Moreover, we described all adverse events (early and late) and studied daily levodopa doses before and 6 months after treatment.

RESULTS

We demonstrated an improvement in motor UPDRS (44%), in axial signs (40% for UPDRS part III axial subscore and 12% for gait) and a reduction of fluctuations (37.5%) and in UPDRS part IV dyskinesia (20%). These significant results are observed without any change in the quality-of-life. Adverse events were due to PEG positioning for four patients, the equipment (pump, connection, inner tube) for all patients and levodopa for four patients. Daily levodopa dose had to be increased 13.5%.

CONCLUSION

Duodopa can be considered as a new treatment strategy providing significant improvements in motor fluctuations, dyskinesia and severe axial signs. These results were demonstrated in very advanced PD patients, who had been excluded from previous studies, with cognitive disorders and for some of them dopaminergic psychosis well controlled by medications.

STN-DBS frequency effects on freezing of gait in advanced Parkinson disease

BACKGROUND

Severe gait disturbances and freezing episodes (frequently resistant to optimal dopaminergic treatment) often appear in advanced Parkinson disease (PD). Even several years after initiation, high-frequency subthalamic nucleus deep brain stimulation (STN-DBS) is still very effective for controlling segmental symptoms. However, there are no long-term data on the management of gait disorders and freezing in STN-DBS.

OBJECTIVES

To compare the effects of various STN-DBS parameters on freezing of gait and to determine whether such effects are more related to stimulation energy (usual voltages vs high voltages at 130 Hz) or frequency (130 Hz vs approximately half this frequency: 60 Hz).

METHODS

We blindly assessed STN-DBS parameters in 13 PD patients reporting severe gait disorders. We compared the effects on gait of two different voltages (the patient's usual voltage [median 3 volts] and a high voltage [median 3.7 volts]) and two different frequencies (60 and 130 Hz, while maintaining the same total energy delivered) vs "off-stimulation" conditions.

RESULTS

The number of freezing episodes was significantly lower at the 60-Hz "high voltage/equivalent energy" and higher at the 130-Hz/high voltage than for "off stimulation." The slight improvement in the Unified Parkinson's Disease Rating Scale motor score observed (at 130 Hz) did not achieve statistical significance.

CONCLUSIONS

Our results prompt consideration of a new strategy for two-stage subthalamic nucleus deep brain stimulation (STN-DBS) frequency optimization, with stimulation at 130 Hz and the usual voltage during the initial years of STN-DBS and then at 60 Hz at a high voltage in Parkinson disease patients who develop severe gait disorders.

Improvement of gait by chronic, high doses of methylphenidate in patients with advanced Parkinson's disease

BACKGROUND

Therapeutic management of gait disorders in patients with advanced Parkinson's disease (PD) can sometimes be disappointing, since dopaminergic drug treatments and subthalamic nucleus (STN) stimulation are more effective for limb-related parkinsonian signs than for gait disorders. Gait disorders could also be partly related to norepinephrine system impairment, and the pharmacological modulation of both dopamine and norepinephrine pathways could potentially improve the symptomatology.

AIM

To assess the clinical value of chronic, high doses of methylphenidate (MPD) in patients with PD having gait disorders, despite their use of optimal dopaminergic doses and STN stimulation parameters.

METHODS

Efficacy was blindly assessed on video for 17 patients in the absence of L-dopa and again after acute administration of the drug, both before and after a 3-month course of MPD, using a Stand-Walk-Sit (SWS) Test, the Tinetti Scale, the Unified Parkinson's Disease Rating Scale (UPDRS) part III score and the Dyskinesia Rating Scale.

RESULTS

An improvement was observed in the number of steps and time in the SWS Test, the number of freezing episodes, the Tinetti Scale score and the UPDRS part III score in the absence of L-dopa after 3 months of taking MPD. The L-dopa-induced improvement in these various scores was also stronger after the 3-month course of MPD than before. The Epworth Sleepiness Scale score fell dramatically in all patients. No significant induction of adverse effects was found.

INTERPRETATION

Chronic, high doses of MPD improved gait and motor symptoms in the absence of L-dopa and increased the intensity of response of these symptoms to L-dopa in a population with advanced PD.