Publications by authors named "Jacques de Keyser"

Predicting the long-term outcome of multiple sclerosis (MS) remains an important challenge to this day. As the gut microbiota is emerging as a potential player in MS, we investigated in this study whether gut microbial composition at baseline is related to long-term disability worsening in a longitudinal cohort of 111 MS patients. Fecal samples and extensive host metadata were collected at baseline and 3 months post-baseline, with additional repeated neurological measurements performed over (median) 4.

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A high Neutrophil-to-Lymphocyte ratio (NLR) in patients with acute ischemic stroke (AIS) has been associated with post-stroke infections, but it's role as an early predictive biomarker for post-stroke pneumonia (PSP) and urinary tract infection (UTI) is not clear. To investigate the usefulness of NLR obtained within 24 h after AIS for predicting PSP and UTI in the first week. Clinical and laboratory data were retrieved from the University Hospital Brussels stroke database/electronic record system.

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Objective: To explore the effects of low-frequency repetitive transcranial magnetic stimulation (LF rTMS) on cortico-striatal-cerebellar resting state functional connectivity in Parkinson's disease (PD), with and without dyskinesias.

Methods: Because there is increasing evidence of an involvement of the pre-supplementary motor area (pre-SMA) in the pathophysiology of levodopa induced dyskinesias, we targeted the right pre-SMA with LF rTMS in 17 PD patients. We explored the effects of one sham-controlled LF rTMS session on resting state functional connectivity of interconnected brain regions by using functional MRI, and how it is modified by levodopa.

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Accumulating evidence indicates that mitochondrial energy failure is involved in the progressive axonal degeneration in multiple sclerosis (MS). In patients with MS, it has been shown that both levels of N-acetylaspartate (NAA), which is a marker of axonal mitochondrial energy, and cerebral blood flow (CBF) are reduced in cerebral normal appearing white matter (NAWM). The latter is likely due to the vasoconstrictive action of endothelin-1 (ET-1) produced by reactive astrocytes, which is triggered by local proinflammatory cytokines.

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Background: Spleen volume reduction followed by re-expansion has been described in acute ischemic stroke in both animal and human studies. Splenic contraction might be partially due to sympathetic hyperactivity and might be accompanied by release of splenocytes in the peripheral circulation, leading to immunodepression.

Aims: To investigate whether spleen volume changes in the first week after stroke are associated with post-stroke infections, changes in lymphocytes count and autonomic dysfunction.

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Objective: Multiple sclerosis (MS) is a heterogenous, inflammatory disease of the central nervous system. Microbiota alterations in MS versus healthy controls (HC) are observed, but results are inconsistent. We studied diversity, enterotypes, and specific gut microbial taxa variation between MS and HC, and between MS subgroups.

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Background: Comorbidity and health behaviours may explain heterogeneity regarding cognitive performance in multiple sclerosis. Patient-reported cognitive difficulties have impact but do not consistently correlate with objective cognitive performance. Our study aims to investigate whether health status indicators including comorbidities, body mass index, physical activity, smoking, sleeping behaviour and consumption patterns for fish, alcohol and caffeinated drinks are associated with measures of subjective and objective cognitive performance.

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In the human central nervous system (CN), resting astrocytes do not visually show endothelin-1 (ET-1)-like immunoreactivity. In patients with multiple sclerosis (MS), an inflammatory disorder of the CNS, high levels of ET-1 are found in reactive astrocytes in demyelinated plaques. ET-1 may contribute to the pathology of MS by interrupting the blood-brain-barrier, enhancing inflammatory responses, excitotoxicity and reducing cerebral blood flow.

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Little is known about the interplay between the autonomic nervous system and disease activity in multiple sclerosis (MS). We examined the relationship between heart rate variability (HRV), a reliable measure of vagal nerve function, and disease characteristics in a prospective MS cohort. Standard deviation of each normal-to-normal inter-beat interval (SDNN) and root mean square of successive differences (RMSSD), global indices of HRV, were measured in 114 MS patients, which included four predefined subgroups, and 30 age and sex-matched healthy controls (HC).

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Background: Preclinical studies suggest that fluoxetine has neuroprotective properties that might reduce axonal degeneration in multiple sclerosis (MS).

Objective: To determine whether fluoxetine slows accumulation of disability in progressive MS.

Methods: In a double-blind multicenter phase 2 trial, patients with primary or secondary progressive MS were randomized to fluoxetine 40 mg/day or placebo for a period of 108 weeks.

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Objective: To study the effect of Low Frequency repetitive Transcranial Magnetic Stimulation (LF rTMS) on brain metabolites in late stage Parkinson's disease (PD) patients (disease duration at least 4 years and Hoehn and Yahr (1969) score at least 2 in OFF). Several neuroimaging data support a role for pre-Supplementary Motor Area (pre-SMA) involvement in the pathogenesis of Parkinson's disease. Proton magnetic resonance spectroscopy (H-MRS) measures in vivo metabolites, but results in PD brain remain conflicting and little is known of the effect of LF rTMS thereupon.

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Background: Axonal degeneration is related to long-term disability in patients with multiple sclerosis (MS). The underlying mechanism remains ill understood but appears to involve axonal energetic dysfunction. A globally impaired cerebral blood flow (CBF) has been observed in the normal-appearing white matter (NAWM) of patients with MS, which is probably related to astrocytic overexpression of endothelin-1 (ET-1).

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Background: The added value of brain volume measurements in the clinical practice of multiple sclerosis (MS) has been questioned.

Purpose: To investigate the contribution of volume measures obtained with magnetic resonance scans performed as part of regular care to predict measures of cognitive and physical MS disability in a real-world setting.

Study Type: Retrospective.

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Background: Multiple sclerosis is an inflammatory demyelinating disorder of the central nervous system (CNS). Myelin basic protein (MBP), which is one of the main compounds of CNS myelin, appears to be hypercitrullinated in the brain of patients with MS. We hypothesized that MS is associated with an increased release of citrulline from the brain.

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Tick borne encephalitis (TBE) is an infectious zoonotic disease caused by an RNA virus that is endemic to Central and Eastern Europe, Russia, and large parts of Asia. The tick borne encephalitis virus (TBEV) is transmitted through the saliva of infected ticks and infected goat milk. In the vast majority of cases, an infection with TBEV has a subclinical course.

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Background: Multiple sclerosis (MS) is characterized by a great inter-individual variability in disease course and severity. Some patients experience a rather mild course, controversially called 'benign MS' (BMS). The usefulness of this entity in clinical practice remains unclear.

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Reduced cardiac baroreceptor sensitivity (BRS) after acute stroke is associated with worse outcome. The underlying mechanisms of reduced BRS are unclear. We evaluated cross correlation BRS (xBRS) in 184 patients with suspected acute ischemic stroke within 72 h of symptom onset.

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Article Synopsis
  • Ischemic stroke is a leading cause of death and disability, with tissue plasminogen activator being the only effective drug therapy available, but many patients are ineligible for this treatment.
  • Estradiol (E) demonstrates neuroprotective effects after an acute stroke, but its effectiveness in treating post-stroke conditions, particularly in patients with hypertension, needed further investigation.
  • In studies on rats, E reduced brain injury and neuron degeneration after a stroke, showing neuroprotective benefits in both normotensive and hypertensive models, although hypertension influenced astrocytic response without hindering treatment effectiveness.
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Article Synopsis
  • Multiple sclerosis is an autoimmune disease that damages the central nervous system by mechanisms including neuroinflammation and oxidative stress, where system x (cystine/glutamate antiporter) may play a crucial role by releasing toxic glutamate.
  • A study used Western blotting to analyze the protein expression of xCT, a subunit of system x, in MS patients and in an animal model of MS (EAE), comparing outcomes between different genetically altered mice.
  • The results showed increased expression of xCT in MS-affected tissues but did not alter susceptibility to EAE in xCT knockout mice, indicating that xCT's role may be more significant in immune cells rather than in directly causing demyelination.
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Lesion volume is a meaningful measure in multiple sclerosis (MS) prognosis. Manual lesion segmentation for computing volume in a single or multiple time points is time consuming and suffers from intra and inter-observer variability. In this paper, we present MSmetrix-long: a joint expectation-maximization (EM) framework for two time point white matter (WM) lesion segmentation.

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In vitro and in vivo studies suggest that the astrocytic adrenergic signalling enhances glycogenolysis which provides energy to be transported to nearby cells and in the form of lactate. This energy source is important for motor and cognitive functioning. While it is suspected that the β2-adrenergic receptor on astrocytes might contribute to this energy balance, it has not yet been shown conclusively in vivo.

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