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European Journal of Neurology Feb 2016Phosphorylated α-synuclein (phosαSYN) containing inclusions in neurons (Lewy bodies, LB) and nerve terminals (Lewy neurites, LN), the pathological hallmark of... (Review)
Review
Phosphorylated α-synuclein (phosαSYN) containing inclusions in neurons (Lewy bodies, LB) and nerve terminals (Lewy neurites, LN), the pathological hallmark of Parkinson's disease (PD), are not confined to the central nervous system, but have also been reported in peripheral tissues. However, the usefulness of αSYN/phosαSYN detection in tissues accessible to biopsies as a reliable biomarker for prodromal PD remains unclear. A systematic review of studies using biopsies of skin, olfactory and gastrointestinal (GI) tissues was conducted to evaluate the sensitivity and specificity of both αSYN and phosαSYN staining in PD patients. Data analysis was hampered by the diversity of the methods used, e.g. choice of biopsy sites, tissue processing, staining protocols and evaluation of the findings. Tissue obtained from GI tract/salivary glands (13 post-mortem, 13 in vivo studies) yielded the highest overall sensitivity and specificity compared to skin (three post-mortem, eight in vivo studies) and olfactory mucosa/bulb (six post-mortem studies, one in vivo study). In contrast to phosαSYN, αSYN was more consistently detectable in peripheral tissues of healthy controls. GI tract/salivary glands appear to be the most promising candidate tissue for peripheral biopsy-taking. phosαSYN is considered as the marker of choice to delineate pathological aggregates from normal αSYN regularly found in peripheral neural tissues. However, the sensitivity and specificity of phosαSYN are not yet acceptable for using phosαSYN as a reliable peripheral biomarker for PD in clinical routine. Further refinement regarding the interpretation of the peripheral αSYN/phosαSYN burden and the phenotypical definition of peripheral LB/LN is needed to optimize screening methods for prodromal PD.
Topics: Biomarkers; Gastrointestinal Tract; Humans; Parkinson Disease; Salivary Glands; alpha-Synuclein
PubMed: 26100920
DOI: 10.1111/ene.12753 -
Molecular Neurobiology Oct 2022Neural regeneration has troubled investigators worldwide in the past decades. Currently, cell transplantation emerged as a breakthrough targeted therapy for spinal cord... (Review)
Review
Neural regeneration has troubled investigators worldwide in the past decades. Currently, cell transplantation emerged as a breakthrough targeted therapy for spinal cord injury (SCI) in the neurotrauma field, which provides a promising strategy in neural regeneration. Olfactory ensheathing cells (OECs), a specialized type of glial cells, is considered as the excellent candidate due to its unique variable and intrinsic regeneration-supportive properties. In fact, OECs could support olfactory receptor neuron turnover and axonal extension, which is essential to maintain the function of olfactory nervous system. Hitherto, an increasing number of literatures demonstrate that transplantation of OECs exerts vital roles in neural regeneration and functional recovery after neural injury, including central and peripheral nervous system. It is common knowledge that the deteriorating microenvironment (ischemia, hypoxia, scar, acute and chronic inflammation, etc.) resulting from injured nervous system is adverse for neural regeneration. Interestingly, recent studies indicated that OECs could promote neural repair through improvement of the disastrous microenvironments, especially to the overwhelmed inflammatory responses. Although OECs possess unusual advantages over other cells for neural repair, particularly in SCI, the mechanisms of OEC-mediated neural repair are still controversial with regard to anti-inflammation. Therefore, it is significant to summarize the anti-inflammation property of OECs, which is helpful to understand the biological characteristics of OECs and drive future studies. Here, we mainly focus on the anti-inflammatory role of OECs to make systematic review and discuss OEC-based therapy for CNS injury.
Topics: Anti-Inflammatory Agents; Cell Transplantation; Humans; Nerve Regeneration; Neuroglia; Olfactory Bulb; Spinal Cord; Spinal Cord Injuries
PubMed: 35962300
DOI: 10.1007/s12035-022-02983-4 -
The Journal of Laryngology and Otology Sep 2020Recent scientific literature has widely described a possible major role of smell dysfunction as a specific symptom of coronavirus disease 2019. This systematic review...
OBJECTIVE
Recent scientific literature has widely described a possible major role of smell dysfunction as a specific symptom of coronavirus disease 2019. This systematic review may provide a more holistic approach to current knowledge of the disease.
METHODS
A systematic review was completed using Embase, PubMed and Web of Science databases that considered original articles focused on olfactory evaluation in coronavirus disease 2019 patients, published between March and May 2020, in English language.
RESULTS
From the 483 research papers initially identified, 32 original studies were selected, comprising a total of 17 306 subjects with a laboratory confirmed diagnosis of coronavirus disease 2019. Individual study sample sizes ranged from 6 to 6452 patients. This comprehensive analysis confirmed that olfactory disorders represent an important clinical feature in coronavirus disease 2019, with a prevalence of 11-100 per cent in included patients, although there was heterogeneity in terms of assessment tools and population selection criteria.
CONCLUSION
The results indicate that an accurate clinical evaluation should be carried out using structured questionnaires and tests with olfactory substances.
PubMed: 32928323
DOI: 10.1017/S0022215120002005 -
Chinese Medical Sciences Journal =... Mar 2022Background Anosmia is one of the symptoms in individuals with SARS-CoV-2 infection. In anosmic patients, SARS-CoV-2 temporarily alters the signaling process in olfactory...
Background Anosmia is one of the symptoms in individuals with SARS-CoV-2 infection. In anosmic patients, SARS-CoV-2 temporarily alters the signaling process in olfactory nerve cells and olfactory bulb (OB), which eventually damages the structure of the olfactory epithelium, leading to a permanent disorder in the olfactory pathway that this damaged structure is showed in MRI imaging Methods Two investigators independently searched four databases consisting of PubMed, ProQuest, Scopus, and Web of Science for relevant records as of November 11, 2020 with no time, space, and language restrictions. Google Scholar was also searched for the related resources within the time limit of 2020. All the found articles were reviewed based on the PRISMA flow diagram. Qualitative studies, case reports, editorials, letters, and other non-original studies were excluded from this systematic analysis. Results Initial search yielded 434 records. After reviewing the titles and abstracts, we selected 74 articles; finally, 8 articles were depicted to be investigated and read in full text. The obtained results showed an increase in the width and volume of the olfactory cleft (OC), complete or partial destruction of OC, and complete occlusion of OC in COVID-19 patients. Deformation and degeneration as well as a subtle asymmetry were evident in the OBs. Computed tomography (CT), meganetic resonance imaging (MRI), and positron emission tomography (PET) were used to detect the outcomes of anosmia in these studies. Conclusions The changes in OC are greater than those in OB in patients with COVID-19, mainly due to the inflammatory and immune responses in OC. However, fewer changes in OB are due to neurological or vascular disorders. Topical steroid therapy and topical saline can be helpful.
PubMed: 35256044
DOI: 10.24920/003982 -
International Journal of Infectious... Jan 2024Symptoms from SARS-CoV-2 infection can involve multiple organ systems. Several reviews discussed the neurologic involvement and neuroimaging findings in adults but...
OBJECTIVES
Symptoms from SARS-CoV-2 infection can involve multiple organ systems. Several reviews discussed the neurologic involvement and neuroimaging findings in adults but research on children is lacking. This study aimed to analyze the incidence of neurologic involvement in patients diagnosed with pediatric inflammatory multisystem syndrome temporally associated with COVID-19 (PIMS-TS) or multisystem inflammatory syndrome in children (MIS-C); and also to summarize current literature on possible neuroimaging findings in SARS-CoV-2 infected children.
METHODS
A literature search in six electronic databases was performed to retrieve case series, cohort studies, and cross-sectional studies on neurologic involvement in COVID-19 patients younger than 21 years of age published between December 2019 to September 2023, including COVID-19 patients.
RESULTS
A total of 2224 patients with MIS-C from 10 cohorts and cross-sectional studies suggested that neurologic involvement in these subsets ranges from 8.5% to 32.1%. Symptoms included acute encephalitis, seizures, stroke, cranial nerve palsy, nausea/vomiting, and intracranial hypertension. Neuroradiology findings of 114 children from 50 case reports included splenial or acute disseminated encephalomyelitis (ADEM)-like lesions, cytotoxic brain edema, autoimmune demyelinating diseases, ischemic stroke and arteritis, venous thrombosis, intracranial hemorrhage, meningitis, posterior reversible encephalopathy syndrome, anti-N-methyl-D-aspartate receptor autoimmune encephalitis, acute hemorrhagic leukoencephalitis, hydrocephalus, olfactory bulb atrophy, cerebellitis, and acute necrotizing encephalitis.
CONCLUSION
Radiologic findings of SARS-CoV-2 infection in the pediatric population are diverse. Neuroimaging studies should be considered in critically ill patients to rule out neurologic involvement and facilitate early interventions.
Topics: Adult; Humans; Child; COVID-19; SARS-CoV-2; Cross-Sectional Studies; Posterior Leukoencephalopathy Syndrome; Neuroimaging; Systemic Inflammatory Response Syndrome
PubMed: 37944584
DOI: 10.1016/j.ijid.2023.11.006 -
Molecular Neurobiology Feb 2015Continuous renewal of neurons throughout life in the olfactory system is often thought to be partially attributable to specialized glial cells called olfactory... (Review)
Review
Continuous renewal of neurons throughout life in the olfactory system is often thought to be partially attributable to specialized glial cells called olfactory ensheathing cells (OECs). Hitherto, several studies have demonstrated that transplantation of OECs is one of the most promising strategies available to augment axonal regeneration and functional recovery following damage to the nervous system, including spinal cord injury (SCI). Based on these studies, a number of pre-clinical studies worldwide have been initiated using autologous transplantation of OECs into damaged central and peripheral nervous systems. Although OECs play a major role in promotion of neuron regeneration of the injured central nervous system (CNS), especially to SCI, limited valuable information is available regarding the beneficial characteristics of OECs in facilitating neural regeneration. Moreover, an increasing number of controversial issues related to the biology of OECs and their transplantation must be addressed. This step is important to better understand the cellular and molecular mechanisms modulated by transplanted OECs. To start shedding light into these controversial issues, this paper provides a systematic review regarding OECs' beneficial roles in neural regeneration, and the unique properties of these cells that may exert a potential advantage over other cellular transplants.
Topics: Animals; Cell Adhesion Molecules; Cell Movement; Humans; Nerve Growth Factors; Nerve Regeneration; Olfactory Bulb; Phagocytosis
PubMed: 24615159
DOI: 10.1007/s12035-014-8664-2 -
Skull Base : Official Journal of North... Jan 2011We systematically reviewed the literature concerning the anterior cranial fossa schwannomas to understand their pathogenesis, determine their origin, and standardize the...
We systematically reviewed the literature concerning the anterior cranial fossa schwannomas to understand their pathogenesis, determine their origin, and standardize the terminology. We performed a MEDLINE, EMBASE, and Science Citation Index Expanded search of the literature; age, gender, clinical presentation, presence or absence of hyposmia, radiological features, and apparent origin were analyzed and tabulated. Cases in a context of neurofibromatosis and nasal schwannomas with intracranial extension were not included. Age varied between 14 and 63 years (mean = 30.9). There were 22 male and 11 female patients. The clinical presentation included seizures (n = 15), headache (n = 16), visual deficits (n = 7), cognitive disturbances (n = 3), and rhinorrhea (n = 1). Hyposmia was present in 14 cases, absent in 13 cases (39.3%), and unreported in five. Homogeneous and heterogeneous contrast enhancement was observed in 14 and 15 cases, respectively. The region of the olfactory groove was the probable site in 96.5%. Olfactory tract could be identified in 39.3%. The most probable origin is the meningeal branches of trigeminal nerve or anterior ethmoidal nerves. Thus, olfactory groove schwannoma would better describe its origin and pathogenesis and should be the term preferentially used to name it.
PubMed: 22451797
DOI: 10.1055/s-0030-1262945 -
Journal of Neurology Aug 2021To perform an updated review of the literature on the neurological manifestations of COVID-19-infected patients METHODS: A PRISMA-guideline-based systematic review was...
OBJECTIVE
To perform an updated review of the literature on the neurological manifestations of COVID-19-infected patients METHODS: A PRISMA-guideline-based systematic review was conducted on PubMed, EMBASE, and SCOPUS. Series reporting neurological manifestations of COVID-19 patients were studied.
RESULTS
39 studies and 68,361 laboratory-confirmed COVID-19 patients were included. Up to 21.3% of COVID-19 patients presented neurological symptoms. Headache (5.4%), skeletal muscle injury (5.1%), psychiatric disorders (4.6%), impaired consciousness (2.8%), gustatory/olfactory dysfunction (2.3%), acute cerebrovascular events (1.4%), and dizziness (1.3%), were the most frequently reported neurological manifestations. Ischemic stroke occurred among 1.3% of COVID-19 patients. Other less common neurological manifestations were cranial nerve impairment (0.6%), nerve root and plexus disorders (0.4%), epilepsy (0.7%), and hemorrhagic stroke (0.15%). Impaired consciousness and acute cerebrovascular events were reported in 14% and 4% of patients with a severe disease, respectively, and they were significantly higher compared to non-severe patients (p < 0.05). Individual patient data from 129 COVID-19 patients with acute ischemic stroke (AIS) were extracted: mean age was 64.4 (SD ± 6.2), 78.5% had anterior circulation occlusions, the mean NIHSS was 15 (SD ± 7), and the intra-hospital mortality rate was 22.8%. Admission to the intensive care unit (ICU) was required among 63% of patients.
CONCLUSION
This updated review of literature, shows that headache, skeletal muscle injury, psychiatric disorders, impaired consciousness, and gustatory/olfactory dysfunction were the most common neurological symptoms of COVID-19 patients. Impaired consciousness and acute cerebrovascular events were significantly higher among patients with a severe infection. AIS patients required ICU admission in 63% of cases, while intra-hospital mortality rate was close to 23%.
Topics: Brain Ischemia; COVID-19; Humans; Middle Aged; Nervous System Diseases; SARS-CoV-2; Stroke
PubMed: 33125542
DOI: 10.1007/s00415-020-10285-9 -
Stem Cells Translational Medicine Aug 2016: Evidence for stem cells as a potential intervention for cerebral palsy is emerging. Our objective was to determine the efficacy and safety of stem cells for improving... (Meta-Analysis)
Meta-Analysis Review
UNLABELLED
: Evidence for stem cells as a potential intervention for cerebral palsy is emerging. Our objective was to determine the efficacy and safety of stem cells for improving motor and cognitive function of people with cerebral palsy. Searches were conducted in October 2015 in CENTRAL, EMBASE, MEDLINE, and Cochrane Libraries. Randomized controlled trials and controlled clinical trials of stem cells for cerebral palsy were included. Two authors independently decided upon included trials, extracted data, quality, and risk of bias. The primary outcome was gross motor function. Secondary outcomes were cognitive function and adverse events (AEs). Effects were expressed as standardized mean differences (SMD) with 95% confidence intervals (CI), using a random-effects model. Five trials comprising 328 participants met inclusion criteria. Four cell types were studied: olfactory ensheathing, neural, neural progenitors, and allogeneic umbilical cord blood (UCBs). Transplantation procedures differed from central nervous system neurosurgical transplantation to intravenous/arterial infusion. Participants were followed short-term for only 6 months. Evidence of variable quality indicated a small statistically significant intervention effect from stem cells on gross motor skills (SMD 1.27; 95% CI 0.22, 2.33), with UCBs most effective. There were insufficient and heterogeneous data to compare cognitive effects. Serious AEs were rare (n = 4/135 [3%] stem cells; n = 3/139 [2%] controls). Stem cells appeared to induce short-term improvements in motor skills. Different types of stem cell interventions were compared, meaning the data were heterogeneous and are a study limitation. Further randomized controlled trials are warranted, using rigorous methodologies.
SIGNIFICANCE
Stem cells are emerging as a scientifically plausible treatment and possible cure for cerebral palsy, but are not yet proven. The lack of valid animal models has significantly hampered the scope of clinical trials. Despite the state of current treatment evidence, parents remain optimistic about the potential improvements from stem cell intervention and feel compelled to exhaust all therapeutic options, including stem cell tourism. Receiving unproven therapies from unvalidated sources is potentially dangerous. Thus it is essential that researchers and clinicians stay up to date. A systematic review and meta-analysis summarizing and aggregating current research data may provide more conclusive evidence to inform treatment decision making and help direct future research.
Topics: Adolescent; Adolescent Development; Adult; Brain; Cerebral Palsy; Child; Child Development; Child, Preschool; Cognition; Female; Humans; Infant; Male; Motor Skills; Nerve Regeneration; Neural Stem Cells; Phenotype; Recovery of Function; Risk Factors; Time Factors; Treatment Outcome; Young Adult
PubMed: 27245364
DOI: 10.5966/sctm.2015-0372 -
Academic Radiology Nov 2020An increasing number of neurological complications and corresponding radiological findings have been reported in patients with COVID-19 infection. The purpose of this...
RATIONALE AND OBJECTIVES
An increasing number of neurological complications and corresponding radiological findings have been reported in patients with COVID-19 infection. The purpose of this study is to systematically review the current literature on COVID-19-associated neuroradiological findings and examine the prevalence of different findings in patients with both severe and mild COVID-19 infection.
MATERIALS AND METHODS
A comprehensive literature search of the PubMed and Embase databases was performed. Any studies reporting CT or MRI neuroimaging findings in patients with confirmed COVID-19 infection were included. Patient demographics, main radiological findings, neurological symptoms, and severity of COVID-19 infection were tabulated and quantified according to infection severity.
RESULTS
Sixty-one studies published between 2019 and 2020 comprising 711 patients were analyzed according to severity of respiratory symptoms. The main neuroradiological findings for patients with mild classification were cranial nerve abnormalities, ischemic infarction, and white matter abnormalities, while the main findings in patients with severe classification were white matter abnormalities, ischemic infarction, and hemorrhagic events.
CONCLUSION
Neuroradiological manifestations in COVID-19 infection are highly heterogeneous and differ based on the severity of COVID-19 infection. Cranial nerve abnormalities appear exclusive to mild infection, with a high degree of olfactory tract involvement, while hemorrhagic events are more common in severe infection. Notably, ischemic infarction was equally prevalent in both mild and severe COVID-19 infection. Healthcare providers treating COVID-19 patients should be aware of these potential complications and consider neurological assessment and neuroimaging studies when indicated.
Topics: Betacoronavirus; COVID-19; Coronavirus Infections; Humans; Nervous System Diseases; Pandemics; Pneumonia, Viral; SARS-CoV-2
PubMed: 32912668
DOI: 10.1016/j.acra.2020.08.026