The latest medical research on Neurology
The research magnet gathers the latest research from around the web, based on your specialty area. Below you will find a sample of some of the most recent articles from reputable medical journals about neurology gathered by our medical AI research bot.
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Association between perihematomal perfusion and intracerebral hemorrhage shape.Neuroradiology
The pathophysiological determinants of irregular intracerebral hemorrhage (ICH) shape are unclear. We aimed at characterizing the relationship between perihematomal perfusion and ICH shape.
A single-center cohort of patients with primary ICH was analyzed. Patients underwent computed tomography perfusion within 6 h from onset. Cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) were calculated in the manually outlined perihematomal low-density region. ICH shape was rated on baseline non-contrast CT following international consensus criteria, and predictors of irregular shape were explored with logistic regression.
A total of 150 patients were included, of whom 66 (44%) had irregular shape. Perihematomal CBF was lower in irregular ICH (median 23 vs 35 mL/100 g/min, p<0.001). CBF<20 mL/100 g/min was independently associated with irregular shape (odds ratio 9.67, 95% CI 2.42-38.69, p=0.001).
Our findings suggest that perihematomal hypoperfusion may contribute to the CT appearance of acute ICH.
GliPR1 knockdown by RNA interference exerts anti-glioma effects in vitro and in vivo.Journal of Neuro-Oncology
In human glioblastomas, glioma pathogenesis-related protein1 (GliPR1) is overexpressed and appears to be an oncoprotein. We investigated whether GliPR1 knockdown in glioma cells by RNA interference exerts anti-glioma effects.
Experiments used human glioblastoma cell lines transduced with GliPR1 shRNA (sh#301, sh#258). Transduction produced stringent doxycycline-dependent GliPR1 knockdown in clones (via lentiviral "all-in-one" TetOn-shRNA vector) or stable GliPR1 knockdown in polyclonal cells (via constitutive retroviral-shRNA vector). In vitro assessments included cellular proliferation and clonogenic survival. In vivo assessments in tumor-bearing nude mice included tumor growth and survival.
Using doxycycline-dependent GliPR1 knockdown, shGliPR1-transduced U87-MG clones demonstrated reductions in cellular proliferation in the presence versus absence of doxycycline. Using stable GliPR1 knockdown, polyclonal shGliPR1-transduced U87-MG, A172, and U343-MG cells consistently showed decreased clonogenic survival and induced apoptosis (higher proportion of early apoptotic cells) compared to control shLuc-transduced cells. In tumor-bearing nude mice, using doxycycline-dependent GliPR1 knockdown, subcutaneous and cranial transplantation of the U87-MG clone 980-5 (transduced with GliPR1 sh#301) resulted in reduced subcutaneous tumor volume and cerebral tumor area in doxycycline-treated mice versus those left untreated. Using stable GliPR1 knockdown, nude mice cranially transplanted with polyclonal U87-MG cells transduced with GliPR1 sh#258 had significantly prolonged survival compared to mice cranially transplanted with control shLuc-transduced cells (41 versus 26 days; P < 0.001).
GliPR1 knockdown in glioma cells decreased cellular proliferation, decreased clonogenic survival, and induced apoptosis in vitro, and reduced glioblastoma tumor growth and prolonged survival in vivo. These findings support that GliPR1 may have potential value as a therapeutic target.
The use of proteomics for blood biomarker research in premature infants: a scoping review.Cerebral Palsy
Over the last decade, the use of proteomics in the setting of prematurity has increased and has enabled researchers to successfully identify biomar...
Interictal dysphoric disorder in people with and without epilepsy.Epilepsia
Interictal dysphoric disorder (IDD) has been regarded as an affective disorder occurring only in people with epilepsy (PWE). Data showing similar characteristics and similar prevalence of IDD in patients with migraine and with psychogenic nonepileptic seizures question the epilepsy-specific nature of IDD. The aim of the study was to investigate the nature of IDD in people with prevalent epilepsy with mood disorders and people with mood disorders who are free of neurological disease.
This is a case-control study, with 142 patients with a confirmed diagnosis of epilepsy and major depressive disorder (MDD; cases) and 222 patients with MDD only (controls). MDD diagnosis was confirmed by a structured clinical interview for Diagnostic and Statistical Manual of Mental Disorders, 4th edition (SCID-I-RV). We used the Beck Depression Inventory and the Beck Anxiety Inventory to estimate anxiety and depression levels and the Interictal Dysphoric Disorder Inventory (IDDI) to confirm the presence of IDD. Mann-Whitney U test, Pearson chi-squared, Spearman correlation, and logistic regression were used.
No differences were found in the prevalence of IDD between PWE with MDD and people with MDD alone (88.73% vs. 85.13%, χ2 = .96, p = .32). There were no differences between the groups overall or for any IDDI subscales (all p > .05). In both groups, IDD symptoms were grouped with the same incidence and had the same duration and periodicity. IDD was not associated with epilepsy (odds ratio = .84, 95% confidence interval = .40-1.98, p = .72). No significant correlation was found between epilepsy, demographic characteristics, and all IDDI subscales (all p > .05). Notably, patients with IDD suffered from affective disorders longer (6.68 ± 6.82 years vs. 3.7 ± 3.97 years, p = .001) and also received higher scores on all psychometric scales (all p < .05).
This study does not confirm the specificity of IDD for epilepsy. The presence of IDD symptoms may be associated with a more severe course of MDD and significant anxiety distress.
Cerebrovascular Neuroprotection after Acute Concussion in Adolescents.Annals Neurology
To assess acute cerebrovascular function in concussed adolescents (14-21 years of age), whether it related to resting cerebral hemodynamics, and whether it recovered chronically.
Cerebral vasoreactivity and autoregulation, based on middle cerebral artery blood flow velocity, were assessed in 28 concussed participants (≤14 days of injury) and 29 matched controls. The participants in the concussion group returned for an 8-week follow-up assessment. Over the course of those 8-weeks, participants recorded aerobic exercise frequency and duration.
Between group demographic, clinical, and hemodynamic variables were not significantly different. Vasoreactivity was significantly higher in the concussed group (p=0.02). Within the concussed group, 60% of the variability in resting cerebral blood flow velocity was explained by vasoreactivity and two components of autoregulation - falling slope and effectiveness of autoregulation (adjusted R2 =0.60, p<0.001). Moreover, lower mean arterial pressure, lower responses to increases in arterial pressure, and lower vasoreactivity were significantly associated with larger symptom burden (adjusted R2 =0.72, p<0.01). By the 8-week timepoint, symptom burden, but not vasoreactivity, improved in all but four concussed participants (p<0.01). 8-week change in vasoreactivity was positively associated with aerobic exercise volume (adjusted R2 =0.19, p=0.02).
Concussion resulted in changes in cerebrovascular regulatory mechanisms, which in turn explained the variability in resting cerebral blood flow velocity and acute symptom burden. Furthermore, these alterations persisted chronically despite symptom resolution, but was positively modified by aerobic exercise volume. These findings provide a mechanistic framework for further investigation into underlying cerebrovascular related symptomatology. This article is protected by copyright. All rights reserved.
Speech biomarkers in rapid eye movement sleep behaviour disorder and Parkinson's disease.Annals Neurology
This multi-language study employed simple speech recording and high-end pattern analysis to provide sensitive and reliable non-invasive biomarkers of prodromal vs. manifest alpha-synucleinopathy in patients with idiopathic rapid eye movement sleep behaviour disorder (iRBD) and early-stage Parkinson's disease (PD).
We performed a multicentre study across the Czech, English, German, French and Italian languages at seven centres in Europe and North America. A total of 448 participants (337 males) including 150 with iRBD (mean duration of iRBD across language groups 0.5-3.4 years), 149 with PD (mean duration of disease across language groups 1.7-2.5 years), and 149 healthy controls were recorded; 350 of the participants completed the 12-month follow-up. We developed a fully-automated acoustic quantitative assessment approach for the seven distinctive patterns of hypokinetic dysarthria.
No language differences that impacted clinical parkinsonian phenotypes were found. Compared to the controls, we found significant abnormalities of an overall acoustic speech severity measure via composite dysarthria index for both iRBD (p = 0.002) and PD (p < 0.001). By contrast, only PD (p < 0.001) was perceptually distinct in a blinded subjective analysis. We found significant group differences between PD and controls for monopitch (p < 0.001), prolonged pauses (p < 0.001) and imprecise consonants (p = 0.03); only monopitch was able to differentiate iRBD patients from controls (p = 0.004). At the 12-month follow-up, a slight progression of overall acoustic speech impairment was noted for the iRBD (p = 0.04) and PD (p = 0.03) groups.
Automated speech analysis may provide a useful additional biomarker of parkinsonism for the assessment of disease progression and therapeutic interventions. This article is protected by copyright. All rights reserved.
AIF3 splicing switch triggers neurodegeneration.Molecular Neurodegeneration
Apoptosis-inducing factor (AIF), as a mitochondrial flavoprotein, plays a fundamental role in mitochondrial bioenergetics that is critical for cell survival and also mediates caspase-independent cell death once it is released from mitochondria and translocated to the nucleus under ischemic stroke or neurodegenerative diseases. Although alternative splicing regulation of AIF has been implicated, it remains unknown which AIF splicing isoform will be induced under pathological conditions and how it impacts mitochondrial functions and neurodegeneration in adult brain.
AIF splicing induction in brain was determined by multiple approaches including 5' RACE, Sanger sequencing, splicing-specific PCR assay and bottom-up proteomic analysis. The role of AIF splicing in mitochondria and neurodegeneration was determined by its biochemical properties, cell death analysis, morphological and functional alterations and animal behavior. Three animal models, including loss-of-function harlequin model, gain-of-function AIF3 knockin model and conditional inducible AIF splicing model established using either Cre-loxp recombination or CRISPR/Cas9 techniques, were applied to explore underlying mechanisms of AIF splicing-induced neurodegeneration.
We identified a nature splicing AIF isoform lacking exons 2 and 3 named as AIF3. AIF3 was undetectable under physiological conditions but its expression was increased in mouse and human postmortem brain after stroke. AIF3 splicing in mouse brain caused enlarged ventricles and severe neurodegeneration in the forebrain regions. These AIF3 splicing mice died 2-4 months after birth. AIF3 splicing-triggered neurodegeneration involves both mitochondrial dysfunction and AIF3 nuclear translocation. We showed that AIF3 inhibited NADH oxidase activity, ATP production, oxygen consumption, and mitochondrial biogenesis. In addition, expression of AIF3 significantly increased chromatin condensation and nuclear shrinkage leading to neuronal cell death. However, loss-of-AIF alone in harlequin or gain-of-AIF3 alone in AIF3 knockin mice did not cause robust neurodegeneration as that observed in AIF3 splicing mice.
We identified AIF3 as a disease-inducible isoform and established AIF3 splicing mouse model. The molecular mechanism underlying AIF3 splicing-induced neurodegeneration involves mitochondrial dysfunction and AIF3 nuclear translocation resulting from the synergistic effect of loss-of-AIF and gain-of-AIF3. Our study provides a valuable tool to understand the role of AIF3 splicing in brain and a potential therapeutic target to prevent/delay the progress of neurodegenerative diseases.
Brain MRI and Ophthalmic Biomarkers of Intracranial Pressure.Neurology
To evaluate the utility of brain MRI and ophthalmic biomarkers for the prediction of intracranial hypertension, we have studied the association between six biomarkers and 24-hour intracranial pressure (ICP) monitoring results in 45 patients.
This single-centre observational study includes patients who underwent 24-hour ICP monitoring, brain MRI (within three months) and ophthalmic assessment (during ICP monitoring). Six biomarkers were investigated: pituitary gland shape, vertical tortuosity of the optic nerve, distension of the optic nerve sheath, optic disc protrusion (MRI), papilloedema (slit lamp biomicroscopy) and spontaneous venous pulsations (SVP, infrared video recordings).
Forty-five patients (mean age 39±14SD, 38 females) met the inclusion criteria. All 6 biomarkers had a significant association with 24-hour ICP. Concave pituitary gland was observed with moderately elevated median ICP. Protrusion of the optic disc (MRI), papilloedema and absence of SVP were associated with the highest median ICP values. Twenty patients had raised ICP (median 24-hour ICP>5.96 mmHg, cut-off obtained through Youden index calculation). Patients with all normal biomarkers had normal median ICP in 94% (St.Err.=6%) of the cases. All the patients with 3 or more abnormal biomarkers had intracranial hypertension. The combination of at least one abnormal biomarker in MRI and ophthalmic assessments was highly suggestive of intracranial hypertension (AUC 0.94, 95% CI 0.93-0.94) CONCLUSIONS: Brain MRI and ophthalmic biomarkers can non-invasively guide the management of patients with suspected CSF dynamics abnormalities. Patients with multiple abnormal biomarkers (≥3) or a combination of abnormal MRI and ophthalmic biomarkers are likely to have intracranial hypertension and should be managed promptly.
Trajectory-Based Classification of Recovery in Sensorimotor Complete Traumatic Cervical Spinal Cord Injury.Neurology
To test the hypothesis that sensorimotor complete traumatic cervical spinal cord injury is a heterogenous clinical entity comprising several subpopulations that follow fundamentally different trajectories of neurologic recovery.
We analyzed demographic and injury data from 655 patients who were pooled from 4 prospective longitudinal multicenter studies. Group based trajectory modeling was applied to model neurologic recovery trajectories over the initial 12-months postinjury and to identify predictors of recovery trajectories. Neurologic outcomes included: Upper Extremity Motor Score, Total Motor Scores and AIS grade improvement.
The analysis identified 3 distinct trajectories of neurologic recovery. These clinical courses included: (1) Marginal recovery trajectory: characterized by minimal or no improvement in motor strength or change in AIS grade status (remained grade A); (2) Moderate recovery trajectory: characterized by low baseline motor scores that improved approximately 13 points; or AIS conversion of one grade point; (3) Good recovery trajectory: characterized by baseline motor scores in the upper quartile that improved to near maximum values within 3 months of injury. Patients following the moderate or good recovery trajectories were of younger age, had more caudally located injuries, a higher degree of preserved motor and sensory function at baseline examination and exhibited a greater extent of motor and sensory function in the zone of partial preservation.
Cervical complete SCI can be classified into one of 3 distinct subpopulations with fundamentally different trajectories of neurologic recovery. This study defines unique clinical phenotypes based on potential for recovery, rather than baseline severity of injury alone. This approach may prove beneficial in clinical prognostication and in the design and interpretation of clinical trials in SCI.
Vagus Nerve Stimulation and Seizure Outcomes in Pediatric Refractory Epilepsy: Systematic Review and Meta-Analysis.Neurology
We synthesized evidence for effectiveness of vagus nerve stimulation (VNS) as adjuvant therapy in pediatric drug-resistant epilepsy (DRE) by obtaining pooled estimates for seizure outcomes and analyzing their determinants.
MEDLINE, EMBASE, and Cochrane databases were searched up to July 2019, for original research on VNS in pediatric (≤18 years-of-age) epilepsy. The primary outcome was 50% responder rate (50%-RR), the proportion of patients with ≥50% seizure reduction, at the last reported follow-up. Other outcomes included 50%-RR and proportion of seizure-free patients at additional reported time points. A random effects meta-analysis with restricted maximum likelihood estimation was performed to obtain pooled effect estimates. Meta-regression using multiple linear models was performed to obtain determinants of seizure outcomes and sources of heterogeneity.
A total of 101 studies were included. The pooled prevalence estimates for 50%-RR and seizure freedom at last follow-up (mean 2.54 years) were 56.4% (95% confidence intervals [CIs] 52.4, 60.4) and 11.6% (95% CI 9.6, 13.9) respectively. Fewer anti-seizure medications (ASMs) tried before VNS, and later age at onset of seizures were associated with better seizure outcomes following VNS implantation. An effect of sex-distribution of studies on long-term outcomes and a potential publication bias for short-term outcomes were also observed.
Pooled evidence supports possible effectiveness of VNS in pediatric DRE, although complete seizure freedom is less common. Early referral (fewer trials of ASMs) may be a modifiable factor for desirable seizure outcomes with VNS from a clinical perspective.
Photo-oxygenation by a biocompatible catalyst reduces amyloid-β levels in Alzheimer's disease mice.Brain
Amyloid formation and the deposition of the amyloid-β peptide are hallmarks of Alzheimer's disease pathogenesis. Immunotherapies using anti-amyloid...
Usefulness of magnetic resonance spectroscopy in mesial temporal sclerosis: a systematic review.Neuroradiology
Magnetic resonance spectroscopy (MRS) provides non-invasive information about metabolic features in different regions of the brain affected by mesial temporal sclerosis (MTS).
To review articles analyzing the most common alterations in biochemical parameters in MTS and the applications of MRS in presurgical assessment.
We undertook a systematic literature search for MRS in MTS in PubMed, SCOPUS, and Cochrane based on the MESH terms "Magnetic Resonance Spectroscopy", "Proton Magnetic Resonance Spectroscopy", "Carbon-13 Magnetic Resonance Spectroscopy", "1H-MRS", "31P-MRS", "mesial temporal sclerosis", "hippocampal sclerosis", "mesial temporal seizure", and "mesial temporal epilepsy".
Of the initial 134 articles found, 30 were selected after the exclusion process. Of these, 13 detected a decrease in N-acetylaspartate (NAA), 9 showed a decreased in the ratio NAA/Cho+Cr, and 8 demonstrated a decreased in the ratio NAA/Cr, all of them in the ipsilateral hippocampus. Nine studies also found reduced NAA levels in extrahippocampal regions.
The main findings were a decrease in NAA in the ipsilateral hippocampus. In addition, NAA levels were low outside the hippocampus so MTS could be a more extensive disease. Patients without MTS also presented a decrease in NAA in the ipsilateral hippocampus although NAA was even lower in the MTS patients. Thus, MRS could be useful in the presurgical evaluation to locate the epileptogenic focus, but not specific for the diagnosis of MTS.