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1.
PLoS Biol ; 19(9): e3001358, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34520451

RESUMO

Several lines of study suggest that peripheral metabolism of amyloid beta (Aß) is associated with risk for Alzheimer disease (AD). In blood, greater than 90% of Aß is complexed as an apolipoprotein, raising the possibility of a lipoprotein-mediated axis for AD risk. In this study, we report that genetic modification of C57BL/6J mice engineered to synthesise human Aß only in liver (hepatocyte-specific human amyloid (HSHA) strain) has marked neurodegeneration concomitant with capillary dysfunction, parenchymal extravasation of lipoprotein-Aß, and neurovascular inflammation. Moreover, the HSHA mice showed impaired performance in the passive avoidance test, suggesting impairment in hippocampal-dependent learning. Transmission electron microscopy shows marked neurovascular disruption in HSHA mice. This study provides causal evidence of a lipoprotein-Aß /capillary axis for onset and progression of a neurodegenerative process.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides/biossíntese , Hepatócitos/metabolismo , Peptídeos beta-Amiloides/genética , Animais , Barreira Hematoencefálica/patologia , Encéfalo/irrigação sanguínea , Capilares/patologia , Modelos Animais de Doenças , Humanos , Inflamação , Aprendizagem , Lipoproteínas/metabolismo , Masculino , Camundongos Transgênicos , Degeneração Neural
2.
Neuroradiology ; 66(7): 1225-1233, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38717474

RESUMO

PURPOSE: Morning glory disc anomaly (MGDA) is a rare congenital ophthalmologic disorder. Historically it has been diagnosed fundoscopically, with little in the literature regarding its imaging findings. The purpose of this study is to further characterize the orbital and associated intracranial magnetic resonance imaging (MRI) findings of MGDA in our tertiary pediatric center. METHODS: A retrospective review was performed of fundoscopically-diagnosed cases of MGDA, that had been referred for MRI. All MRI studies were scrutinized for orbital and other intracranial abnormalities known to occur in association with MGDA. RESULTS: 18 of 19 cases of MGDA showed three characteristic MRI findings: funnel-shaped morphology of the posterior optic disc, abnormal soft tissue associated with the retrobulbar optic nerve, and effacement of adjacent subarachnoid spaces. The ipsilateral (intraorbital) optic nerve was larger in one patient and smaller in six. The ipsilateral optic chiasm was larger in two patients and smaller in one. CONCLUSION: This study represents a comprehensive radiological-led investigation into MGDA. It describes the most frequently-encountered MRI findings in MGDA and emphasizes the importance of MRI in this cohort, i.e., in distinguishing MGDA from other posterior globe abnormalities, in assessing the visual pathway, and in screening for associated intracranial abnormalities - skull base/cerebral, vascular, and facial. It hypothesizes neurocristopathy as an underlying cause of MGDA and its associations. Caliber abnormalities of the ipsilateral optic nerve and chiasm are a frequent finding in MGDA. Optic pathway enlargement should not be labeled "glioma". (239/250).


Assuntos
Imageamento por Ressonância Magnética , Disco Óptico , Humanos , Masculino , Feminino , Imageamento por Ressonância Magnética/métodos , Estudos Retrospectivos , Criança , Disco Óptico/anormalidades , Disco Óptico/diagnóstico por imagem , Pré-Escolar , Lactente , Adolescente , Anormalidades do Olho/diagnóstico por imagem
3.
Artigo em Inglês | MEDLINE | ID: mdl-38453632

RESUMO

OBJECTIVES: People may experience a myriad of symptoms after mild traumatic brain injury (mTBI), but the relationship between symptoms and objective assessments is poorly characterized. This study sought to investigate the association between symptoms, resting heart rate (HR), and exercise tolerance in individuals following mTBI, with a secondary aim to examine the relationship between symptom-based clinical profiles and recovery. METHODS: Prospective observational study of adults aged 18 to 65 years who had sustained mTBI within the previous 7 days. Symptoms were assessed using the Post-Concussion Symptom Scale, HR was measured at rest, and exercise tolerance was assessed using the Buffalo Concussion Bike Test. Symptom burden and symptom-based clinical profiles were examined with respect to exercise tolerance and resting HR. RESULTS: Data from 32 participants were assessed (mean age 36.5 ± 12.6 years, 41% female, 5.7 ± 1.1 days since injury). Symptom burden (number of symptoms and symptom severity) was significantly associated with exercise intolerance (P = .002 and P = .025, respectively). Physiological and vestibular-ocular clinical profile composite groups were associated with exercise tolerance (P = .001 and P = .014, respectively), with individuals who were exercise intolerant having a higher mean number of symptoms in each profile than those who were exercise tolerant. Mood-related and autonomic clinical profiles were associated with a higher resting HR (>80 bpm) (P = .048 and P = .028, respectively), suggesting altered autonomic response for participants with symptoms relating to this profile. After adjusting for age and mechanism of injury (sports- or non-sports-related), having a higher mood-related clinical profile was associated with persisting symptoms at 3 months postinjury (adjusted odds ratio = 2.08; 95% CI, 1.11-3.90; P = .013). CONCLUSION: Symptom-based clinical profiles, in conjunction with objective measures such as resting HR and exercise tolerance, are important components of clinical care for those having sustained mTBI. These results provide preliminary support for the concept that specific symptoms are indicative of autonomic dysfunction following mTBI.

4.
Childs Nerv Syst ; 39(4): 857-861, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36658366

RESUMO

Although the posterior fossa is a common location for paediatric brain tumours [1], diffuse glioma isolated to the cerebellum is an extremely rare imaging entity. Only two cases of isolated diffuse paediatric cerebellar glioma have been reported in the English language to the best of our knowledge [2, 3], and only one of these cases had a similar imaging phenotype to our cases [3]. Although somewhat similar to Lhermitte-Duclos (dysplastic gangliocytoma of the cerebellum), the appearances are distinct from other neoplastic entities of the paediatric posterior fossa. Clinical presentation and neurological examination findings are vital however to help differentiate other diffuse pathologies involving the cerebellum such as rhombencephalitis. Presented here are two diffuse cerebellar gliomas in children under the age of 3 with near identical imaging phenotypes demonstrating differing histological and molecular genetic profiles.


Assuntos
Neoplasias Encefálicas , Neoplasias Cerebelares , Glioma , Síndrome do Hamartoma Múltiplo , Humanos , Neoplasias Cerebelares/diagnóstico por imagem , Neoplasias Cerebelares/genética , Imageamento por Ressonância Magnética , Cerebelo/diagnóstico por imagem , Glioma/diagnóstico por imagem , Glioma/genética , Glioma/patologia , Neoplasias Encefálicas/patologia , Síndrome do Hamartoma Múltiplo/genética , Síndrome do Hamartoma Múltiplo/patologia , Síndrome do Hamartoma Múltiplo/cirurgia
5.
Neurochem Res ; 46(5): 1166-1176, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33523394

RESUMO

Poly-arginine peptides R18 and R18D have previously been demonstrated to be neuroprotective in ischaemic stroke models. Here we examined the proteolytic stability and efficacy of R18 and R18D in reducing infarct core growth and preserving the ischaemic penumbra following middle cerebral artery occlusion (MCAO) in the Sprague Dawley rat. R18 (300 or 1000 nmol/kg), R18D (300 nmol/kg) or saline were administered intravenously 10 min after MCAO induced using a filament. Serial perfusion and diffusion-weighted MRI imaging was performed to measure changes in the infarct core and penumbra from time points between 45- and 225-min post-occlusion. Repeated measures analyses of infarct growth and penumbral tissue size were evaluated using generalised linear mixed models (GLMMs). R18D (300 nmol/kg) was most effective in slowing infarct core growth (46.8 mm3 reduction; p < 0.001) and preserving penumbral tissue (21.6% increase; p < 0.001), followed by R18 at the 300 nmol/kg dose (core: 29.5 mm3 reduction; p < 0.001, penumbra: 12.5% increase; p < 0.001). R18 at the 1000 nmol/kg dose had a significant impact in slowing core growth (19.5 mm3 reduction; p = 0.026), but only a modest impact on penumbral preservation (6.9% increase; p = 0.062). The in vitro anti-excitotoxic neuroprotective efficacy of R18D was also demonstrated to be unaffected when preincubated for 1-3 h or overnight, in a cell lysate prepared from dying neurons or with the proteolytic enzyme, plasmin, whereas the neuroprotective efficacy of R18 was significantly reduced after a 2-h incubation. These findings highlight the capacity of poly-arginine peptides to reduce infarct growth and preserve the ischaemic penumbra, and confirm the superior efficacy and proteolytic stability of R18D, which indicates that this peptide is likely to retain its neuroprotective properties when co-administered with alteplase during thrombolysis for acute ischaemic stroke.


Assuntos
Infarto da Artéria Cerebral Média/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Peptídeos/uso terapêutico , Animais , Encéfalo/efeitos dos fármacos , Células Cultivadas , Fibrinolisina/metabolismo , Masculino , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/metabolismo , Peptídeos/química , Peptídeos/metabolismo , Estabilidade Proteica , Ratos Sprague-Dawley , Estereoisomerismo
6.
Hum Mol Genet ; 25(19): 4302-4314, 2016 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-27506977

RESUMO

RNA polymerase III is essential for the transcription of non-coding RNAs, including tRNAs. Mutations in the genes encoding its largest subunits are known to cause hypomyelinating leukodystrophies (HLD7) with pathogenetic mechanisms hypothesised to involve impaired availability of tRNAs. We have identified a founder mutation in the POLR3A gene that leads to aberrant splicing, a premature termination codon and partial deficiency of the canonical full-length transcript. Our clinical and imaging data showed no evidence of the previously reported white matter or cerebellar involvement; instead the affected brain structures included the striatum and red nuclei with the ensuing clinical manifestations. Our transcriptome-wide investigations revealed an overall decrease in the levels of Pol III-transcribed tRNAs and an imbalance in the levels of regulatory ncRNAs such as small nuclear and nucleolar RNAs (snRNAs and snoRNAs). In addition, the Pol III mutation was found to exert complex downstream effects on the Pol II transcriptome, affecting the general regulation of RNA metabolism.


Assuntos
Corpo Estriado/patologia , Degeneração Neural/congênito , RNA Polimerase III/genética , Transcrição Gênica , Transcriptoma/genética , Adulto , Cerebelo/metabolismo , Cerebelo/patologia , Criança , Corpo Estriado/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Neostriado/metabolismo , Neostriado/patologia , Degeneração Neural/genética , Degeneração Neural/patologia , Fenótipo , Splicing de RNA/genética , RNA de Transferência/genética
7.
Intern Med J ; 48(2): 194-197, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29415360

RESUMO

A case of metformin encephalopathy is presented in a patient on haemodialysis for end-stage diabetic renal failure. The patient presented with frequent falls and clinical signs of Parkinsonism, on a background of recent anorexia and significant weight loss. Magnetic resonance imaging showed bilateral, symmetrical abnormalities centred on the lentiform nuclei. Metformin was withheld and signs and symptoms quickly resolved. We hypothesise that metformin may cause thiamine deficiency in patients with end-stage renal failure resulting in a specific metabolic encephalopathy.


Assuntos
Encefalopatias/induzido quimicamente , Encefalopatias/tratamento farmacológico , Hipoglicemiantes/efeitos adversos , Metformina/efeitos adversos , Tiamina/uso terapêutico , Complexo Vitamínico B/uso terapêutico , Adulto , Encefalopatias/diagnóstico por imagem , Nefropatias Diabéticas/diagnóstico por imagem , Nefropatias Diabéticas/terapia , Feminino , Humanos
8.
BMC Pediatr ; 18(1): 252, 2018 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-30064388

RESUMO

BACKGROUND: Of children with hemiplegic cerebral palsy, 75% have impaired somatosensory function, which contributes to learned non-use of the affected upper limb. Currently, motor learning approaches are used to improve upper-limb motor skills in these children, but few studies have examined the effect of any intervention to ameliorate somatosensory impairments. Recently, Sense© training was piloted with a paediatric sample, seven children with hemiplegic cerebral palsy, demonstrating statistically and clinically significant change in limb position sense, goal performance and bimanual hand-use. This paper describes a protocol for a Randomised Controlled Trial of Sense© for Kids training, hypothesising that its receipt will improve somatosensory discrimination ability more than placebo (dose-matched Goal Directed Therapy via Home Program). Secondary hypotheses include that it will alter brain activation in somatosensory processing regions, white-matter characteristics of the thalamocortical tracts and improve bimanual function, activity and participation more than Goal Directed Training via Home Program. METHODS AND DESIGN: This is a single blind, randomised matched-pair, placebo-controlled trial. Participants will be aged 6-15 years with a confirmed description of hemiplegic cerebral palsy and somatosensory discrimination impairment, as measured by the sense©_assess Kids. Participants will be randomly allocated to receive 3h a week for 6 weeks of either Sense© for Kids or Goal Directed Therapy via Home Program. Children will be matched on age and severity of somatosensory discrimination impairment. The primary outcome will be somatosensory discrimination ability, measured by sense©_assess Kids score. Secondary outcomes will include degree of brain activation in response to a somatosensory task measured by functional MRI, changes in the white matter of the thalamocortical tract measured by diffusion MRI, bimanual motor function, activity and participation. DISCUSSION: This study will assess the efficacy of an intervention to increase somatosensory discrimination ability in children with cerebral palsy. It will explore clinically important questions about the efficacy of intervening in somatosensation impairment to improve bimanual motor function, compared with focusing on motor impairment directly, and whether focusing on motor impairment alone can affect somatosensory ability. TRIAL REGISTRATION: This trial is registered with the Australian New Zealand Clinical Trials Registry, registration number: ACTRN12618000348257. World Health Organisation universal trial number: U1111-1210-1726.


Assuntos
Paralisia Cerebral/reabilitação , Hemiplegia/reabilitação , Hipestesia/terapia , Tato , Adolescente , Paralisia Cerebral/complicações , Paralisia Cerebral/fisiopatologia , Criança , Hemiplegia/fisiopatologia , Humanos , Hipestesia/etiologia , Imageamento por Ressonância Magnética , Projetos de Pesquisa , Método Simples-Cego
9.
Hepatology ; 61(5): 1555-64, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25524401

RESUMO

UNLABELLED: Iron is implicated in the pathogenesis of liver injury and insulin resistance (IR) and thus phlebotomy has been proposed as a treatment for nonalcoholic fatty liver disease (NAFLD). We performed a prospective 6-month randomized, controlled trial examining the impact of phlebotomy on the background of lifestyle advice in patients with NAFLD. Primary endpoints were hepatic steatosis (HS; quantified by magnetic resonance imaging) and liver injury (determined by alanine aminotransaminase [ALT] and cytokeratin-18 [CK-18]). Secondary endpoints included insulin resistance measured by the insulin sensitivity index (ISI) and homeostasis model of assessment (HOMA), and systemic lipid peroxidation determined by plasma F2-isoprostane levels. A total of 74 subjects were randomized (33 phlebotomy and 41 control). The phlebotomy group underwent a median (range) of 7 (1-19) venesection sessions and had a significantly greater reduction in ferritin levels over 6 months, compared to controls (-148 ± 114 vs. -38 ± 89 ng/mL; P < 0.001). At 6 months, there was no difference between phlebotomy and control groups in HS (17.7% vs. 15.5%; P = 0.4), serum ALT (36 vs. 46 IU/L; P = 0.4), or CK-18 levels (175 vs. 196 U/L; P = 0.9). Similarly, there was no difference in end-of-study ISI (2.5 vs. 2.7; P = 0.9), HOMA (3.2 vs. 3.2; P = 0.6), or F2-isoprostane levels (1,332 vs. 1,190 pmmol/L; P = 0.6) between phlebotomy and control groups. No differences in any endpoint were noted in patients with hyperferritinemia at baseline. Among patients undergoing phlebotomy, there was no correlation between number of phlebotomy sessions and change in HS, liver injury, or IR from baseline to end of study. CONCLUSION: Reduction in ferritin by phlebotomy does not improve liver enzymes, hepatic fat, or IR in subjects with NAFLD.


Assuntos
Estilo de Vida , Hepatopatia Gordurosa não Alcoólica/terapia , Flebotomia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
10.
Am J Hum Genet ; 91(3): 553-64, 2012 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-22901947

RESUMO

Autosomal-recessive congenital cerebellar ataxia was identified in Roma patients originating from a small subisolate with a known strong founder effect. Patients presented with global developmental delay, moderate to severe stance and gait ataxia, dysarthria, mild dysdiadochokinesia, dysmetria and tremors, intellectual deficit, and mild pyramidal signs. Brain imaging revealed progressive generalized cerebellar atrophy, and inferior vermian hypoplasia and/or a constitutionally small brain were observed in some patients. Exome sequencing, used for linkage analysis on extracted SNP genotypes and for mutation detection, identified two novel (i.e., not found in any database) variants located 7 bp apart within a unique 6q24 linkage region. Both mutations cosegregated with the disease in five affected families, in which all ten patients were homozygous. The mutated gene, GRM1, encodes metabotropic glutamate receptor mGluR1, which is highly expressed in cerebellar Purkinje cells and plays an important role in cerebellar development and synaptic plasticity. The two mutations affect a gene region critical for alternative splicing and the generation of receptor isoforms; they are a 3 bp exon 8 deletion and an intron 8 splicing mutation (c.2652_2654del and c.2660+2T>G, respectively [RefSeq accession number NM_000838.3]). The functional impact of the deletion is unclear and is overshadowed by the splicing defect. Although ataxia lymphoblastoid cell lines expressed GRM1 at levels comparable to those of control cells, the aberrant transcripts skipped exon 8 or ended in intron 8 and encoded various species of nonfunctional receptors either lacking the transmembrane domain and containing abnormal intracellular tails or completely missing the tail. The study implicates mGluR1 in human hereditary ataxia. It also illustrates the potential of the Roma founder populations for mutation identification by exome sequencing.


Assuntos
Ataxia Cerebelar/genética , Genes Recessivos , Mutação , Receptores de Glutamato Metabotrópico/genética , Adulto , Sequência de Bases , Ataxia Cerebelar/diagnóstico , Criança , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Linhagem
11.
Exp Brain Res ; 233(6): 1703-10, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25757959

RESUMO

This study examined brain activation in children with developmental coordination disorder (DCD) to reveal areas that may contribute to poor movement execution and/or abundant motor overflow. Using functional magnetic resonance imaging, 13 boys with DCD (mean age = 9.6 years ±0.8) and 13 typically developing controls (mean age = 9.3 years ±0.6) were scanned performing two tasks (finger sequencing and hand clenching) with their dominant hand, while a four-finger motion sensor recorded contralateral motor overflow on their non-dominant hand. Despite displaying increased motor overflow on both functional tasks during scanning, there were no obvious activation deficits in the DCD group to explain the abundant motor overflow seen. However, children with DCD were found to display decreased activation in the left superior frontal gyrus on the finger-sequencing task, an area which plays an integral role in executive and spatially oriented processing. Decreased activation was also seen in the left inferior frontal gyrus, an area typically active during the observation and imitation of hand movements. Finally, increased activation in the right postcentral gyrus was seen in children with DCD, which may reflect increased reliance on somatosensory information during the execution of complex fine motor tasks.


Assuntos
Córtex Cerebral/fisiopatologia , Dedos/fisiologia , Transtornos das Habilidades Motoras/patologia , Transtornos das Habilidades Motoras/fisiopatologia , Movimento/fisiologia , Análise de Variância , Córtex Cerebral/irrigação sanguínea , Criança , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Oxigênio/sangue
12.
Top Stroke Rehabil ; : 1-12, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38526999

RESUMO

BACKGROUND: Post-stroke lateropulsion is prevalent and associated with poor rehabilitation outcomes; however, data regarding long-term function associated with lateropulsion are lacking. OBJECTIVES: This study aimed to explore lateropulsion resolution and associations between lateropulsion, functional outcomes, and fall occurrence up to 12 months post-stroke. METHODS: Participants for this prospective, longitudinal cohort study were recruited from a Stroke Rehabilitation Unit (SRU). Assessments were conducted at SRU admission, at discharge, and at three, six, nine, and twelve months post-stroke. Outcomes included the Four-Point Pusher Score (4PPS), Functional Independence Measure (FIM), and fall occurrence. Longitudinal outcomes were modeled using generalized linear mixed-effects models. RESULTS: The final analyses included data from 144 participants. Eighty-two participants (56.9) had lateropulsion (4PPS ≥ 1) on admission. Odds of resolved lateropulsion (4PPS = 0) increased longitudinally from discharge for people who participated in rehabilitation physiotherapy (OR: 9.7, 28.1, 43.1, 81.3: <0.001 at three, six, nine, and twelve months respectively). The greatest FIM improvement among participants in all 4PPS categories occurred during the SRU inpatient phase. The probability of falls post-discharge was greatest among participants with 4PPS = 1 at three months, when compared with 4PPS = 0 (p= 0.022). CONCLUSIONS: This study showed that lateropulsion can continue to resolve up to one year post-stroke. Earlier lateropulsion resolution was associated with ongoing rehabilitation physiotherapy participation. Long-term functional gains were maintained among people discharged home, whereas functional status deteriorated after six months among those in residential care. Study findings will allow rehabilitation and service providers to better plan for and accommodate the long-term rehabilitation and care needs of people with post-stroke lateropulsion.

13.
Top Stroke Rehabil ; : 1-10, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38598484

RESUMO

BACKGROUND: Post-stroke lateropulsion is prevalent and has been associated with varied lesion locations, but existing imaging studies are limited by small participant cohorts. Evidence to guide lateropulsion rehabilitation is also limited. Improved understanding of lesion localization associated with lateropulsion post-stroke may inform more targeted intervention approaches. OBJECTIVES: This study investigated the associations between stroke neuroimaging data and presence of lateropulsion at inpatient rehabilitation admission. METHODS: This prospective, observational study included participants aged ≥65 years, admitted for inpatient stroke rehabilitation. Using routinely collected clinical neuroimaging data, stroke type, location, and volume were reported, and their association with lateropulsion presence (Four-Point Pusher Score - 4PPS) at admission was explored. RESULTS: Of 144 included participants, 82 (56.9%) had lateropulsion (4PPS ≥1). Lateropulsion presence was univariately associated with hemorrhagic stroke (p = 0.002), frontal cortical involvement (OR = 2.17, 95%CI 1.02-6.46), and white matter involvement (OR = 2.45, 95%CI 1.24-4.85), particularly frontal white matter (p = 0.021). Lesions involving the posterior limb of the internal capsule (OR = 2.88, 95% CI 1.14-7.27) and those involving the entire thalamus (OR = 1.0, p = 0.03) were associated with lateropulsion presence. When stratified by stroke type, no specific location was significantly associated with lateropulsion presence in hemorrhagic strokes. Among participants with ischemic stroke, involvement of the pre-central gyrus (OR = 2.45, 95%CI 1.05-5.76), post-central gyrus (OR = 2.76, 95%CI 1.15-6.60), inferior parietal cortex (OR = 3.95, 95%CI 1.43-10.90), and supramarginal gyrus (OR = 3.73, 95%CI 1.25-11.13) were associated with lateropulsion presence. The stroke laterality and size were not significantly associated with lateropulsion presence. CONCLUSIONS: The findings indicate a role of network disconnection in the post-stroke lateropulsion presence. Future, larger-cohort lesion-network mapping studies are recommended.

14.
BJR Case Rep ; 8(1): 20210105, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35136641

RESUMO

Hirayama disease is a rare cervical myelopathy characterised by asymmetrical upper limb weakness and muscle atrophy in the forearm and hand. MRI of the cervical spine plays an essential role in diagnosis, however, the characteristic findings are often only seen when the patient is imaged with the neck in flexion. We present a case of a 15-year-old male who presented with left forearm and hand weakness with muscle wasting. An MRI of the cervical spine with the neck in a neutral position demonstrated atrophy of the spinal cord with intrinsic signal abnormality between C5 and C7. Further imaging with the patient's neck in flexion demonstrated the hallmark features of Hirayama disease. There was anterior displacement of the thecal sac and spinal cord, and an enlarged, crescent-shaped dorsal epidural space which enhanced following i.v. gadolinium administration. The atrophic segment of cord contacted the posterior vertebral bodies when the neck was in full flexion. This case highlights the importance of imaging patients suspected of having this entity with the neck in full flexion in order to make a diagnosis.

15.
BMJ Open ; 12(2): e058826, 2022 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-35190446

RESUMO

INTRODUCTION: Preclinical, clinical and epidemiological studies support the hypothesis that aberrant systemic metabolism of amyloid beta (Aß) in the peripheral circulation is causally related to the development of Alzheimer's disease (AD). Specifically, recent studies suggest that increased plasma concentrations of lipoprotein-Aß compromise the brain microvasculature, resulting in extravasation and retention of the lipoprotein-Aß moiety. The latter results in an inflammatory response and neurodegeneration ensues. Probucol, a historic cholesterol-lowering drug, has been shown in murine models to suppress lipoprotein-Aß secretion, concomitant with maintaining blood-brain-barrier function, suppressing neurovascular inflammation and supporting cognitive function. This protocol details the probucol in Alzheimer's study, a drug intervention trial investigating if probucol has potential to attenuate cognitive decline, delay brain atrophy and reduce cerebral amyloid burden in patients with mild-to-moderate AD. METHODS AND ANALYSIS: The study is a phase II, randomised, placebo-controlled, double-blind single-site clinical trial held in Perth, Australia. The target sample is 314 participants with mild-to-moderate AD. Participants will be recruited and randomised (1:1) to a 104-week intervention consisting of placebo induction for 2 weeks followed by 102 weeks of probucol (Lorelco) or placebo. The primary outcome is changed in cognitive performance determined via the Alzheimer's Disease Assessment Scales-Cognitive Subscale test between baseline and 104 weeks. Secondary outcomes measures will be the change in brain structure and function, cerebral amyloid load, quality of life, and the safety and tolerability of Lorelco, after a 104week intervention. ETHICS AND DISSEMINATION: The study has been approved by the Bellberry Limited Human Research Ethics Committee (approval number: HREC2019-11-1063; Version 4, 6 October 2021). Informed consent will be obtained from participants prior to any study procedures being performed. The investigator group will disseminate study findings through peer-reviewed publications, key conferences and local stakeholder events. TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trials Registry (ACTRN12621000726853).


Assuntos
Doença de Alzheimer , Probucol , Peptídeos beta-Amiloides/metabolismo , Animais , Austrália , Ensaios Clínicos Fase II como Assunto , Cognição , Método Duplo-Cego , Humanos , Camundongos , Probucol/farmacologia , Probucol/uso terapêutico , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
16.
Neuroscience ; 467: 218-236, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34087394

RESUMO

Traumatic brain injury (TBI) is a common but heterogeneous injury underpinned by numerous complex and interrelated pathophysiological mechanisms. An essential trace element, iron is abundant within the brain and involved in many fundamental neurobiological processes, including oxygen transportation, oxidative phosphorylation, myelin production and maintenance, as well as neurotransmitter synthesis and metabolism. Excessive levels of iron are neurotoxic and thus iron homeostasis is tightly regulated in the brain, however, many details about the mechanisms by which this is achieved are yet to be elucidated. A key mediator of oxidative stress, mitochondrial dysfunction and neuroinflammatory response, iron dysregulation is an important contributor to secondary injury in TBI. Advances in neuroimaging that leverage magnetic susceptibility properties have enabled increasingly comprehensive investigations into the distribution and behaviour of iron in the brain amongst healthy individuals as well as disease states such as TBI. Quantitative Susceptibility Mapping (QSM) is an advanced neuroimaging technique that promises quantitative estimation of local magnetic susceptibility at the voxel level. In this review, we provide an overview of brain iron and its homeostasis, describe recent advances enabling applications of QSM within the context of TBI and summarise the current state of the literature. Although limited, the emergent research suggests that QSM is a promising neuroimaging technique that can be used to investigate a host of pathophysiological changes that are associated with TBI.


Assuntos
Lesões Encefálicas Traumáticas , Imageamento por Ressonância Magnética , Encéfalo/diagnóstico por imagem , Lesões Encefálicas Traumáticas/diagnóstico por imagem , Mapeamento Encefálico , Humanos , Ferro , Neuroimagem
17.
BMJ Open ; 11(5): e046460, 2021 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-33986061

RESUMO

INTRODUCTION: Mild traumatic brain injury (mTBI) is a complex injury with heterogeneous physical, cognitive, emotional and functional outcomes. Many who sustain mTBI recover within 2 weeks of injury; however, approximately 10%-20% of individuals experience mTBI symptoms beyond this 'typical' recovery timeframe, known as persistent post-concussion symptoms (PPCS). Despite increasing interest in PPCS, uncertainty remains regarding its prevalence in community-based populations and the extent to which poor recovery may be identified using early predictive markers. OBJECTIVE: (1) Establish a research dataset of people who have experienced mTBI and document their recovery trajectories; (2) Evaluate a broad range of novel and established prognostic factors for inclusion in a predictive model for PPCS. METHODS AND ANALYSIS: The Concussion Recovery Study (CREST) is a prospective, longitudinal observational cohort study conducted in Perth, Western Australia. CREST is recruiting adults aged 18-65 from medical and community-based settings with acute diagnosis of mTBI. CREST will create a state-wide research dataset of mTBI cases, with data being collected in two phases. Phase I collates data on demographics, medical background, lifestyle habits, nature of injury and acute mTBI symptomatology. In Phase II, participants undergo neuropsychological evaluation, exercise tolerance and vestibular/ocular motor screening, MRI, quantitative electroencephalography and blood-based biomarker assessment. Follow-up is conducted via telephone interview at 1, 3, 6 and 12 months after injury. Primary outcome measures are presence of PPCS and quality of life, as measured by the Post-Concussion Symptom Scale and the Quality of Life after Brain Injury questionnaires, respectively. Multivariate modelling will examine the prognostic value of promising factors. ETHICS AND DISSEMINATION: Human Research Ethics Committees of Royal Perth Hospital (#RGS0000003024), Curtin University (HRE2019-0209), Ramsay Health Care (#2009) and St John of God Health Care (#1628) have approved this study protocol. Findings will be published in peer-reviewed journals and presented at scientific conferences. TRIAL REGISTRATION NUMBER: ACTRN12619001226190.


Assuntos
Concussão Encefálica , Síndrome Pós-Concussão , Adulto , Concussão Encefálica/diagnóstico , Estudos de Coortes , Humanos , Estudos Observacionais como Assunto , Síndrome Pós-Concussão/diagnóstico , Estudos Prospectivos , Qualidade de Vida , Austrália Ocidental
18.
J Neuroinflammation ; 7: 71, 2010 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-21034449

RESUMO

BACKGROUND: Vascular dysfunction and brain inflammation are thought to contribute to the pathophysiology of cerebral injury in acute stroke. However acute inflammation and vascular dysfunction may simply be markers of an acute phase response to cerebral injury, reflecting the size of the cerebral lesion. We aimed to determine if systemic markers of vascular dysfunction and inflammation are independently associated with concentrations of the astroglial protein S100B, a marker of brain injury, in participants with acute ischaemic stroke. METHODS: Fifty-seven men and women recruited within 96 hours of acute ischaemic stroke at two tertiary hospitals participated in this cross sectional observational study. Clinical, imaging (stroke lesions area measured with perfusion CT) and laboratory data were the independent variables and co-variates. The outcome variable was serum S100B concentration, analysed by multivariate regression. RESULTS: High sensitivity-CRP (B = 0.41) and lesion area (B = 0.69) were independently associated with S100B concentration (R2 = 0.75, p < 0.01). Other variables with significant univariate associations with S100B concentration were not independently associated with S100B concentration in the final multivariate model. CONCLUSION: The degree of systemic inflammation is associated with S100B concentration in acute ischaemic stroke, independent of the size of the ischaemic lesion.


Assuntos
Biomarcadores/sangue , Inflamação/sangue , Fatores de Crescimento Neural/sangue , Proteínas S100/sangue , Acidente Vascular Cerebral/sangue , Idoso , Estudos Transversais , Feminino , Humanos , Inflamação/patologia , Masculino , Pessoa de Meia-Idade , Subunidade beta da Proteína Ligante de Cálcio S100 , Acidente Vascular Cerebral/patologia
19.
Brain Sci ; 10(1)2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31906443

RESUMO

BACKGROUND: Persisting post-concussion symptoms (PPCS) is a complex, multifaceted condition in which individuals continue to experience the symptoms of mild traumatic brain injury (mTBI; concussion) beyond the timeframe that it typically takes to recover. Currently, there is no way of knowing which individuals may develop this condition. METHOD: Patients presenting to a hospital emergency department (ED) within 48 h of sustaining a mTBI underwent neuropsychological assessment and demographic, injury-related information and blood samples were collected. Concentrations of blood-based biomarkers neuron specific enolase, neurofilament protein-light, and glial fibrillary acidic protein were assessed, and a subset of patients also underwent diffusion tensor-magnetic resonance imaging; both relative to healthy controls. Individuals were classified as having PPCS if they reported a score of 25 or higher on the Rivermead Postconcussion Symptoms Questionnaire at ~28 days post-injury. Univariate exact logistic regression was performed to identify measures that may be predictive of PPCS. Neuroimaging data were examined for differences in fractional anisotropy (FA) and mean diffusivity in regions of interest. RESULTS: Of n = 36 individuals, three (8.33%) were classified as having PPCS. Increased performance on the Repeatable Battery for the Assessment of Neuropsychological Status Update Total Score (OR = 0.81, 95% CI: 0.61-0.95, p = 0.004), Immediate Memory (OR = 0.79, 95% CI: 0.56-0.94, p = 0.001), and Attention (OR = 0.86, 95% CI: 0.71-0.97, p = 0.007) indices, as well as faster completion of the Trails Making Test B (OR = 1.06, 95% CI: 1.00-1.12, p = 0.032) at ED presentation were associated with a statistically significant decreased odds of an individual being classified as having PPCS. There was no significant association between blood-based biomarkers and PPCS in this small sample, although glial fibrillary acidic protein (GFAP) was significantly increased in individuals with mTBI relative to healthy controls. Furthermore, relative to healthy age and sex-matched controls (n = 8), individuals with mTBI (n = 14) had higher levels of FA within the left inferior frontal occipital fasciculus (t (18.06) = -3.01, p = 0.008). CONCLUSION: Performance on neuropsychological measures may be useful for predicting PPCS, but further investigation is required to elucidate the utility of this and other potential predictors.

20.
Neurology ; 89(24): 2406-2412, 2017 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-29117957

RESUMO

OBJECTIVE: The purpose of this study of sickle cell disease (SCD) was to determine whether arteriopathy, measurable as intracranial vessel signal loss on magnetic resonance angiography (MRA), was associated with low nocturnal hemoglobin oxygen saturation (SpO2) or hemolytic rate, measurable as reticulocytosis or unconjugated hyperbilirubinemia. METHODS: Ninety-five East London children with SCD without prior stroke had overnight pulse oximetry, of whom 47 (26 boys, 39 hemoglobin SS; mean age 9.1 ± 3.1 years) also had MRA, transcranial Doppler (TCD), steady-state hemoglobin, and reticulocytes within 34 months. Two radiologists blinded to the other data graded arteriopathy on MRA as 0 (none) or as increasing severity grades 1, 2, or 3. RESULTS: Grades 2 or 3 arteriopathy (n = 24; 2 with abnormal TCD) predicted stroke/TIA compared with grades 0 and 1 (log-rank χ2 [1, n = 47] = 8.1, p = 0.004). Mean overnight SpO2 correlated negatively with reticulocyte percentage (r = -0.387; p = 0.007). Despite no significant differences across the degrees of arteriopathy in genotype, mean overnight SpO2 was higher (p < 0.01) in those with grade 0 (97.0% ± 1.6%) than those with grades 2 (93.9 ± 3.7%) or 3 (93.5% ± 3.0%) arteriopathy. Unconjugated bilirubin was not associated but reticulocyte percentage was lower (p < 0.001) in those with grade 0 than those with grades 2 and 3 arteriopathy. In multivariable logistic regression, lower mean overnight SpO2 (odds ratio 0.50, 95% confidence interval 0.26-0.96; p < 0.01) predicted arteriopathy independent of reticulocyte percentage (odds ratio 1.47, 95% confidence interval 1.15-1.87; p = 0.003). CONCLUSION: Low nocturnal SpO2 and reticulocytosis are associated with intracranial arteriopathy in children with SCD. Preventative strategies might reduce stroke risk.


Assuntos
Anemia Falciforme/metabolismo , Doenças Arteriais Cerebrais/diagnóstico por imagem , Hiperbilirrubinemia/metabolismo , Hipóxia/metabolismo , Oxiemoglobinas/metabolismo , Anemia Falciforme/complicações , Anemia Falciforme/diagnóstico por imagem , Doenças Arteriais Cerebrais/epidemiologia , Doenças Arteriais Cerebrais/etiologia , Doenças Arteriais Cerebrais/metabolismo , Criança , Estudos de Coortes , Feminino , Humanos , Hipóxia/epidemiologia , Hipóxia/etiologia , Ataque Isquêmico Transitório/epidemiologia , Modelos Logísticos , Londres/epidemiologia , Angiografia por Ressonância Magnética , Imageamento por Ressonância Magnética , Masculino , Análise Multivariada , Oximetria , Reticulocitose , Índice de Gravidade de Doença , Acidente Vascular Cerebral/epidemiologia , Ultrassonografia Doppler Transcraniana
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