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Progress in Neuro-psychopharmacology &... Jun 2024Growing evidence supports dopamine's role in aversive states, yet systematic reviews focusing on dopamine receptors in defensive behaviors are lacking. This study... (Review)
Review
Growing evidence supports dopamine's role in aversive states, yet systematic reviews focusing on dopamine receptors in defensive behaviors are lacking. This study presents a systematic review of the literature examining the influence of drugs acting on dopamine D2-like receptors on unconditioned and conditioned fear in rodents. The review reveals a predominant use of adult male rats in the studies, with limited inclusion of female rodents. Commonly employed tests include the elevated plus maze and auditory-cued fear conditioning. The findings indicate that systemic administration of D2-like drugs has a notable impact on both innate and learned aversive states. Generally, antagonists tend to increase unconditioned fear, while agonists decrease it. Moreover, both agonists and antagonists typically reduce conditioned fear. These effects are attributed to the involvement of distinct neural circuits in these states. The observed increase in unconditioned fear induced by D2-like antagonists aligns with dopamine's role in suppressing midbrain-mediated responses. Conversely, the reduction in conditioned fear is likely a result of blocking dopamine activity in the mesolimbic pathway. The study highlights the need for future research to delve into sex differences, explore alternative testing paradigms, and identify specific neural substrates. Such investigations have the potential to advance our understanding of the neurobiology of aversive states and enhance the therapeutic application of dopaminergic agents.
PubMed: 38950840
DOI: 10.1016/j.pnpbp.2024.111080 -
Frontiers in Medicine 2024Systemic sclerosis (SSc) is a disease of a very heterogeneous clinical picture and immunological profile with progression rate that varies between individuals. Although...
BACKGROUND
Systemic sclerosis (SSc) is a disease of a very heterogeneous clinical picture and immunological profile with progression rate that varies between individuals. Although hearing deterioration is not a complaint that comes to the fore in SSc patients, as it is not life-threatening compared to many other more severe symptoms of this disease, it can significantly impair the quality of life. Medical literature concerning this problem is rather scarce.
MATERIALS AND METHODS
In this article we systematically reviewed the medical publications concerning hearing impairment in patients with systemic sclerosis to evaluate current understanding of this complex problem. Following PRISMA guidelines a total of 19 papers were found and analysed including 11 original studies and 8 case reports.
RESULTS
Although it seems that hearing impairment in SSc patients is relatively more common than in the general population, based on the analysis of available literature, no firm conclusions regarding its frequency and pathomechanism can be drawn yet. Microangiopathy leading to damage to the sensory cells of the inner ear is suspected to be the main mechanism of hearing loss, although damage to the higher levels of the auditory pathway appears to be underestimated due to incomplete audiological diagnosis.
CONCLUSION
Undoubtedly, the reason for the difficulty in such an evaluation are the complex and still not fully elucidated pathomechanism of SSc, the individually variable dynamics of the disease and the unique heterogeneity of symptoms. Nevertheless, further studies in larger and appropriately selected groups of patients, focused more on the dynamics of microangiopathy and not solely on clinical symptoms could provide answers to many key questions in this regard.
PubMed: 38562372
DOI: 10.3389/fmed.2024.1322170 -
Frontiers in Psychology 2023Congenital toxoplasmosis (CT) occurs mainly by primary maternal infection during pregnancy. It is estimated that the incidence of vertical transmission to the fetus is...
BACKGROUND
Congenital toxoplasmosis (CT) occurs mainly by primary maternal infection during pregnancy. It is estimated that the incidence of vertical transmission to the fetus is 20% and that infected women are more likely to have a premature birth or low birth weight neonate since there is an association between CT and the rate of premature birth and low birth weight. In addition to severe neurological and ophthalmic consequences, hearing disorders such as hearing loss are also among the clinical manifestations seen in children with CT. Given the above, the objective of this study is to verify what are the auditory disorders seen in children with CT.
METHODS
This literature review was structured according to the PRISMA statement and based on the terms of Study Target Population, Intervention, Comparison, Outcomes, and Study Types (PICOS). To obtain the studies, the following electronic databases were consulted: PubMed, Web of Science, Scopus, and Lilacs. The combined terms used for the search were: ("auditory evoked potentials" OR "hearing" OR "hearing loss") AND ("congenital toxoplasmosis"). The selection of articles was carried out independently, blindly, by two of the authors, to minimize risk of bias.
RESULTS
The search in the databases identified 172 articles, after excluding duplicate articles, 105 studies were identified. From the selection made by reading the titles and abstracts, 11 studies were selected for full-text reading. A total of 94 studies were excluded. An article was selected from the list of references. Therefore, 12 studies were included in the final analysis. It was observed that a significant percentage of studies sought to study the peripheral auditory pathway, verifying the occurrence or association between hearing loss and the presence of congenital infection. Only two studies evaluated the central auditory pathway, using the Brainstem Auditory Evoked Potential (BAEP) and the Frequency Following Response (FFR).
CONCLUSION
Toxoplasmosis affects not only the peripheral areas but central areas as well. Most studies suggest this pathology as a risk factor for both peripheral and central impairment. Research has found a greater association between CT and mild to moderate hearing loss, in addition to alterations in exams such as BAEP and FFR. These data recommend that CT be reported as a global public health problem and can help assess complications and impacts of hearing disorders as a result of CT. There is a gap about studies that retract the co-occurrence between CT and other Risk Indicators for Hearing Loss (RIHL), such as prematurity, permanence in the intensive care unit, and use of ototoxic medications, lack of longitudinal studies, that accompany the development of hearing and language of children with CT, since the consequences of this infection may be late.
PubMed: 38298366
DOI: 10.3389/fpsyg.2023.1286211 -
Molecular Neurobiology Dec 2023Migraine is a complex neurovascular disorder that is characterized by severe behavioral, sensory, visual, and/or auditory symptoms. It has been labeled as one of the ten... (Review)
Review
Migraine is a complex neurovascular disorder that is characterized by severe behavioral, sensory, visual, and/or auditory symptoms. It has been labeled as one of the ten most disabling medical illnesses in the world by the World Health Organization (Aagaard et al Sci Transl Med 6(237):237ra65, 2014). According to a recent report by the American Migraine Foundation (Shoulson et al Ann Neurol 25(3):252-9, 1989), around 148 million people in the world currently suffer from migraine. On the basis of presence of aura, migraine is classified into two major subtypes: migraine with aura (Aagaard et al Sci Transl Med 6(237):237ra65, 2014) and migraine without aura. (Aagaard K et al Sci Transl Med 6(237):237ra65, 2014) Many complex genetic mechanisms have been proposed in the pathophysiology of migraine but specific pathways associated with the different subtypes of migraine have not yet been explored. Various approaches including candidate gene association studies (CGAS) and genome-wide association studies (Fan et al Headache: J Head Face Pain 54(4):709-715, 2014). have identified the genetic markers associated with migraine and its subtypes. Several single nucleotide polymorphisms (Kaur et al Egyp J Neurol, Psychiatry Neurosurg 55(1):1-7, 2019) within genes involved in ion homeostasis, solute transport, synaptic transmission, cortical excitability, and vascular function have been associated with the disorder. Currently, the diagnosis of migraine is majorly behavioral with no focus on the genetic markers and thereby the therapeutic intervention specific to subtypes. Therefore, there is a need to explore genetic variants significantly associated with MA and MO as susceptibility markers in the diagnosis and targets for therapeutic interventions in the specific subtypes of migraine. Although the proper characterization of pathways based on different subtypes is yet to be studied, this review aims to make a first attempt to compile the information available on various genetic variants and the molecular mechanisms involved with the development of MA and MO. An attempt has also been made to suggest novel candidate genes based on their function to be explored by future research.
PubMed: 38135854
DOI: 10.1007/s12035-023-03837-3 -
International Archives of... Oct 2023Factors of intrauterine growth restriction have been responsible for the births of full-term babies small for their gestational age (SGA). Scientific evidence points... (Review)
Review
Factors of intrauterine growth restriction have been responsible for the births of full-term babies small for their gestational age (SGA). Scientific evidence points that this restriction can cause changes in the neural maturation process. To analyze the absolute latencies and interpeak intervals of brainstem auditory evoked potential waves in full-term and SGA children to investigate whether there are changes of neural maturation in this population. The search for articles that reported the assessment of brainstem auditory evoked potential in SGA newborns compared with a control, appropriate for their gestational age, both born full-term, for the entire period available in the database research until October 31, 2021 was performed based on the MEDLINE/PubMed Central and on the Latin America and the Caribbean Health Sciences Literature and Virtual Health Library electronic databases. A total of 311 studies were found in the database research. Out of this total, 10 studies were included in the review, 5 of which were eligible for the meta-analysis, involving a total of 473 participants of both genders, with 193 participants belonging to the study group and 280 to the control group. Differences between the groups were only observed in the absolute latency of wave V (95% confidence interval [CI]: 0.02-0.15; < 0.01). The SGA condition is responsible for the appearance of brainstem neural conduction dysfunction measured by the brainstem auditory evoked potentials, probably by the maturation process of the auditory pathway of this population.
PubMed: 37876702
DOI: 10.1055/s-0042-1758215 -
Journal of Neuroradiology = Journal de... Mar 2024Cochlear implants have advanced the management of severe to profound deafness. However, there is a strong disparity in hearing performance after implantation from one... (Review)
Review
INTRODUCTION
Cochlear implants have advanced the management of severe to profound deafness. However, there is a strong disparity in hearing performance after implantation from one patient to another. Moreover, there are several advanced kinds of imaging assessment before cochlear implantation. Microstructural white fiber degeneration can be studied with Diffusion weighted MRI (DWI) or tractography of the central auditory pathways. Functional MRI (fMRI) allows us to evaluate brain function, and CT or MRI segmentation to better detect inner ear anomalies.
OBJECTIVE
This literature review aims to evaluate how helpful pre-implantation anatomic imaging can be to predict hearing rehabilitation outcomes in deaf patients. These techniques include DWI and fMRI of the central auditory pathways, and automated labyrinth segmentation by CT scan, cone beam CT and MRI.
DESIGN
This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were selected by searching in PubMed and by checking the reference lists of relevant articles. Inclusion criteria were adults over 18, with unilateral or bilateral hearing loss, who had DWI acquisition or fMRI or CT/ Cone Beam CT/ MRI image segmentation.
RESULTS
After reviewing 172 articles, we finally included 51. Studies on DWI showed changes in the central auditory pathways affecting the white matter, extending to the primary and non-primary auditory cortices, even in sudden and mild hearing impairment. Hearing loss patients show a reorganization of brain activity in various areas, such as the auditory and visual cortices, as well as regions involved in language and emotions, according to fMRI studies. Deep Learning's automatic segmentation produces the best CT segmentation in just a few seconds. MRI segmentation is mainly used to evaluate fluid space of the inner ear and determine the presence of an endolymphatic hydrops.
CONCLUSION
Before cochlear implantation, a DWI with tractography can evaluate the central auditory pathways up to the primary and non-primary auditory cortices. This data is then used to generate predictions on the auditory rehabilitation of patients. A CT segmentation with systematic 3D reconstruction allow a better evaluation of cochlear malformations and predictable difficulties during surgery.
Topics: Adult; Humans; Cochlear Implantation; Cochlear Implants; Deafness; Magnetic Resonance Imaging; Treatment Outcome
PubMed: 37806523
DOI: 10.1016/j.neurad.2023.10.002 -
PloS One 2023High-altitude (HA) affects sensory organ response, but its effects on the inner ear are not fully understood. The present scoping review aimed to collect the available... (Meta-Analysis)
Meta-Analysis
PURPOSE
High-altitude (HA) affects sensory organ response, but its effects on the inner ear are not fully understood. The present scoping review aimed to collect the available evidence about HA effects on the inner ear with focus on auditory function.
METHODS
The scoping review was conducted following the guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analysis extension for scoping reviews. PubMed, Scopus, and Web of Science electronic databases were systematically searched to identify studies conducted in the last 20 years, which quantified in healthy subjects the effects of HA on auditory function.
RESULTS
The systematic search identified 17 studies on a total population of 888 subjects (88.7% male, age: 27.8 ± 4.1 years; median sample size of 15 subjects). Nine studies were conducted in a simulated environment and eight during real expeditions at HA. To quantify auditory function, six studies performed pure tone audiometry, four studies measured otoacoustic emissions (OAE) and eight studies measured auditory evoked responses (AER). Study protocols presented heterogeneity in the spatio-temporal patterns of HA exposure, with highly varying maximal altitudes and exposure durations.
CONCLUSION
Most studies reported a reduction of auditory function with HA in terms of either elevation of auditory thresholds, lengthening of AER latencies, reduction of distortion-product and transient-evoked OAEs. Future studies in larger populations, using standardized protocols and multi-technique auditory function evaluation, are needed to further characterize the spatio-temporal pattern of HA effects along the auditory pathways and clarify the pathophysiological implications and reversibility of the observed changes.
Topics: Humans; Male; Young Adult; Adult; Female; Altitude; Hearing; Otoacoustic Emissions, Spontaneous; Auditory Pathways; Altitude Sickness
PubMed: 37733697
DOI: 10.1371/journal.pone.0291919 -
Frontiers in Neurology 2023Hearing can be impaired in many neurological conditions and can even represent a forme of specific disorders. Auditory function can be measured by either subjective or... (Review)
Review
Neuroinflammatory disorders of the brain and inner ear: a systematic review of auditory function in patients with migraine, multiple sclerosis, and neurodegeneration to support the idea of an innovative 'window of discovery'.
BACKGROUND
Hearing can be impaired in many neurological conditions and can even represent a forme of specific disorders. Auditory function can be measured by either subjective or objective tests. Objective tests are more useful in identifying which auditory pathway (superior or inferior) is most affected by disease. The inner ear's perilymphatic fluid communicates with the cerebrospinal fluid (CSF) via the cochlear aqueduct representing a window from which pathological changes in the contents of the CSF due to brain inflammation could, therefore, spread to and cause inflammation in the inner ear, damaging inner hair cells and leading to hearing impairment identifiable on tests of auditory function.
METHODS
A systematic review of the literature was performed, searching for papers with case-control studies that analyzed the hearing and migraine function in patients with neuro-inflammatory, neurodegenerative disorders. With data extracted from these papers, the risk of patients with neurological distortion product otoacoustic emission (DPOAE) was then calculated.
RESULTS
Patients with neurological disorders (headache, Parkinson's disease, and multiple sclerosis) had a higher risk of having peripheral auditory deficits when compared to healthy individuals.
CONCLUSION
Existing data lend credence to the hypothesis that inflammatory mediators transmitted via fluid exchange across this communication window, thereby represents a key pathobiological mechanism capable of culminating in hearing disturbances associated with neuroimmunological and neuroinflammatory disorders of the nervous system.
PubMed: 37662038
DOI: 10.3389/fneur.2023.1204132 -
Frontiers in Human Neuroscience 2023First, to discuss sex differences in auditory function between women and men, and whether cyclic fluctuations in levels of female sex hormones (i.e., estradiol and... (Review)
Review
AIMS
First, to discuss sex differences in auditory function between women and men, and whether cyclic fluctuations in levels of female sex hormones (i.e., estradiol and progesterone) affect auditory function in pre-menopausal and post-menopausal women. Second, to systematically review the literature concerning the discussed patterns in order to give an overview of the methodologies used in research. Last, to identify the gap in knowledge and to make recommendations for future work.
METHODS FOR THE SYSTEMATIC REVIEW
Population, Exposure, Control, Outcome and Study design (PECOS) criteria were used in developing the review questions. The review protocol follows the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and was pre-registered in the Prospective Register of Systematic Reviews (PROSPERO; CRD42020201480). Data Sources: EMBASE, PubMed, MEDLINE (Ovid), PsycINFO, ComDisDome, CINAHL, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL) via Cochrane Library, and scanning reference lists of relevant studies, and internet resources (i.e., Mendeley) were used. Only studies published between 1999 and 2022, in English, or in English translation, were included. The quality of evidence was assessed using the Newcastle-Ottawa Scale (NOS).
RESULTS
Sex differences: Women had more sensitive hearing (measured at the level of peripheral and central auditory system) than men. Cyclic fluctuations: Auditory function in women fluctuated during the menstrual cycle, while no such fluctuations in men over the same time period were reported. Hearing sensitivity improved in women during the late follicular phase, and decrease during the luteal phase, implying an effect of female sex hormones, although the specific effects of estradiol and progesterone fluctuations on the central auditory system remain unclear. Hearing sensitivity in women declined rapidly at the onset of menopause.
CONCLUSION
The review has shown the following. Consistent sex differences exist in auditory function across the auditory pathway with pre-menopausal women often showing better function than age-matched men. Moreover, pre-menopausal women show fluctuations in hearing function across the menstrual cycle with a better function during the peak of estradiol or when the ratio of estradiol to progesterone is high. Third, menopause marks the onset of hearing loss in women, characterized by a rapid decline in hearing sensitivity and a more pronounced loss than in age-matched men. Finally, the systematic review highlights the need for well-designed and -controlled studies to evaluate the influence of estradiol and progesterone on hearing by consistently including control groups (e.g., age-matched man), using objective tests to measure hormonal levels (e.g., in saliva or blood), and by testing participants at different points across the menstrual cycle.
SYSTEMATIC REVIEW REGISTRATION
https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020201480, identifier CRD42020201480.
PubMed: 37151900
DOI: 10.3389/fnhum.2023.1077409 -
Neurological Sciences : Official... Sep 2023Mutations in FDXR gene, involved in mitochondrial pathway, cause a rare recessive neurological disorder with variable severity of phenotypes. The most common... (Review)
Review
BACKGROUND AND AIMS
Mutations in FDXR gene, involved in mitochondrial pathway, cause a rare recessive neurological disorder with variable severity of phenotypes. The most common presentation includes optic and/or auditory neuropathy, variably associated to developmental delay or regression, global hypotonia, pyramidal, cerebellar signs, and seizures. The review of clinical findings in previously described cases from literature reveals also a significant incidence of sensorimotor peripheral polyneuropathy (22.72%) and ataxia (43.18%). To date, 44 patients with FDXR mutations have been reported. We describe here on two new patients, siblings, who presented with a quite different phenotype compared to previously described patients.
METHODS
Clinical, neurophysiological, and genetic features of two siblings and a systematic literature review focused on the clinical spectrum of the disease are described.
RESULTS
Both patients presented with an acute-sub-acute onset of peripheral neuropathy and only in later stages of the disease developed the typical features of FDXR-associated disease.
INTERPRETATION
The peculiar clinical presentation at onset and the evolution of the disease in our patients and in some cases revised from the literature shed lights on a new possible phenotype of FDXR-associated disease: a peripheral neuropathy which can mimic an acute inflammatory disease.
Topics: Humans; Ataxia; Cerebellar Ataxia; Diagnosis, Differential; Mutation; Peripheral Nervous System Diseases; Phenotype; Ferredoxin-NADP Reductase
PubMed: 37046037
DOI: 10.1007/s10072-023-06790-0