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Brain Sciences Dec 2023Current consensus diagnostic criteria for vestibular migraine (VM) describes this as an episodic disorder. However, a minority of patients report prolonged (>72 h... (Review)
Review
Current consensus diagnostic criteria for vestibular migraine (VM) describes this as an episodic disorder. However, a minority of patients report prolonged (>72 h duration) or even persistent VM symptoms, prompting whether a chronic variant of vestibular migraine (CVM) should be introduced to the current classification and how best to define it. Here we summarize current evidence of such a potential chronic variant of VM and critically review proposed definitions for CVM. Potential approaches to establish a diagnostic framework for CVM include (a) following the distinction between episodic and chronic migraine headaches, namely, frequent and/or prolonged episodes of VM (but not persistent vertigo or dizziness) in the context of chronic migraine headaches or (b) daily dizzy spells over more than 6 months that responded well to prophylactic anti-migraine therapy. A key challenge when defining diagnostic criteria for CVM is how to distinguish it from other chronic vestibular syndromes such as motion sickness, persistent postural-perceptual dizziness (PPPD), and mal de débarquement syndrome. Indeed, more than 50% of patients with PPPD and up to 46% with mal de débarquement syndrome fulfil diagnostic criteria for episodic migraine headaches, suggesting these disorders may all lie along a spectrum. We propose that when VM becomes persistent, it is best classified as PPPD but that VM and PPPD are not mutually exclusive, such that patients with PPPD need not have features of VM, and the triggering event for persistent dizziness may be independent of migraine. However, further research is needed to better characterize the spectrum of clinical phenotypes in patients with chronic dizziness, migraine headaches and anxiety, to define whether a chronic variant of VM sufficiently differs from current persistent dizziness definitions.
PubMed: 38137140
DOI: 10.3390/brainsci13121692 -
Cortex; a Journal Devoted To the Study... Apr 2024Developmental prosopagnosia (DP) is characterised by difficulties recognising face identities and is associated with diverse co-occurring object recognition...
Developmental prosopagnosia (DP) is characterised by difficulties recognising face identities and is associated with diverse co-occurring object recognition difficulties. The high co-occurrence rate and heterogeneity of associated difficulties in DP is an intrinsic feature of developmental conditions, where co-occurrence of difficulties is the rule, rather than the exception. However, despite its name, cognitive and neural theories of DP rarely consider the developmental context in which these difficulties occur. This leaves a large gap in our understanding of how DP emerges in light of the developmental trajectory of face recognition. Here, we argue that progress in the field requires re-considering the developmental origins of differences in face recognition abilities, rather than studying the end-state alone. In practice, considering development in DP necessitates a re-evaluation of current approaches in recruitment, design, and analyses.
Topics: Humans; Prosopagnosia; Facial Recognition; Visual Perception; Pattern Recognition, Visual
PubMed: 38460488
DOI: 10.1016/j.cortex.2024.02.006 -
The British Journal of Psychiatry : the... Oct 2023Cannabis has been associated with poorer mental health, but little is known of the effect of synthetic cannabinoids or cannabidiol (often referred to as CBD).
BACKGROUND
Cannabis has been associated with poorer mental health, but little is known of the effect of synthetic cannabinoids or cannabidiol (often referred to as CBD).
AIMS
To investigate associations of cannabis, synthetic cannabinoids and cannabidiol with mental health in adolescence.
METHOD
We conducted a cross-sectional analysis with 13- to 14-year-old adolescents across England and Wales in 2019-2020. Multilevel logistic regression was used to examine the association of lifetime use of cannabis, synthetic cannabinoids and cannabidiol with self-reported symptoms of probable depression, anxiety, conduct disorder and auditory hallucinations.
RESULTS
Of the 6672 adolescents who participated, 5.2% reported using of cannabis, 1.9% reported using cannabidiol and 0.6% reported using synthetic cannabinoids. After correction for multiple testing, adolescents who had used these substances were significantly more likely to report a probable depressive, anxiety or conduct disorder, as well as auditory hallucinations, than those who had not. Adjustment for socioeconomic disadvantage had little effect on associations, but weekly tobacco use resulted in marked attenuation of associations. The association of cannabis use with probable anxiety and depressive disorders was weaker in those who reported using cannabidiol than those who did not. There was little evidence of an interaction between synthetic cannabinoids and cannabidiol.
CONCLUSIONS
To our knowledge, this study provides the first general population evidence that synthetic cannabinoids and cannabidiol are associated with probable mental health disorders in adolescence. These associations require replication, ideally with prospective cohorts and stronger study designs.
Topics: Humans; Adolescent; Cannabidiol; Cannabis; Mental Health; Cross-Sectional Studies; Prospective Studies; Cannabinoids; Hallucinations; United Kingdom
PubMed: 37485911
DOI: 10.1192/bjp.2023.91 -
Proceedings. Biological Sciences Dec 2023We reveal a unique visual perception before feature-integration of colour and motion in infants. Visual perception is established by the integration of multiple...
We reveal a unique visual perception before feature-integration of colour and motion in infants. Visual perception is established by the integration of multiple features, such as colour and motion direction. The mechanism of feature integration benefits from the ongoing interplay between feedforward and feedback loops, yet our comprehension of this causal connection remains incomplete. Researchers have explored the role of recurrent processing in feature integration by studying a visual illusion called 'misbinding', wherein visual characteristics are erroneously merged, resulting in a perception distinct from the originally presented stimuli. Anatomical investigations have revealed that the neural pathways responsible for recurrent connections are underdeveloped in early infants. Therefore, there is a possibility that younger infants could potentially perceive the physically presented visual information that adults miss due to misbinding. Here, we demonstrate that infants less than half a year old showed no misbinding; thus, they perceived the physically presented visual information, while infants more than half a year old perceived incorrectly integrated visual information, showing misbinding. Our findings indicate that recurrent processing barely functions in infants younger than six months of age and that visual information that should have been originally integrated is perceived as it is without being integrated.
Topics: Adult; Humans; Infant; Motion Perception; Visual Perception; Illusions
PubMed: 38052443
DOI: 10.1098/rspb.2023.2134 -
The Journal of Clinical Psychiatry Jul 2023Delusions and hallucinations are common in Alzheimer disease (AD) and Parkinson disease (PD), especially in the later stages of illness. Antipsychotic drugs are... (Meta-Analysis)
Meta-Analysis
Delusions and hallucinations are common in Alzheimer disease (AD) and Parkinson disease (PD), especially in the later stages of illness. Antipsychotic drugs are effective in treating these psychotic symptoms but are associated with an increased risk of serious adverse events, including mortality. There is therefore a need to explore other treatment approaches. In this context, a recent individual patient data meta-analysis of 17 randomized controlled trials (RCTs) conducted in AD (12 RCTs) and PD (5 RCTs) found that the cholinesterase inhibitor (ChEI) drugs donepezil, rivastigmine, and galantamine attenuated the severity of both delusions and hallucinations in both AD and PD. Most of these trials were 24 weeks in duration. The effect sizes, expressed as standardized mean differences (SMDs), were, however, small, lying in the -0.08 to -0.14 range. These values are so small as to be perhaps clinically insignificant. When analyses were restricted to data from patients who actually had delusions and hallucinations at baseline, all effect sizes became larger, lying in the -0.13 to -0.39 range; however, after correcting for multiple hypothesis testing, only the finding for delusions in PD remained statistically significant. The meta-analysis did not provide information on what the best doses were, how long it took for improvement to become evident, and what proportion of patients showed remission from psychotic symptoms. Whereas the signal identified in this meta-analysis merits examination in appropriately designed RCTs, the findings of the meta-analysis may not much change current treatment strategies because patients with dementia would probably anyway receive a ChEI. Therefore, if psychotic symptoms persist for 24 weeks despite optimally dosed ChEI treatment, and if behavioral and psychosocial interventions do not help, clinicians may need to consider the potential benefits vs risks of other drugs, such as atypical antipsychotics and pimavanserin, in a shared decision-making process.
Topics: Humans; Cholinesterase Inhibitors; Alzheimer Disease; Delusions; Parkinson Disease; Antipsychotic Agents; Hallucinations
PubMed: 37530610
DOI: 10.4088/JCP.23f15009 -
Journal of the Neurological Sciences Dec 2023The consequences of pain in early onset Parkinson's disease (EOPD) remain under appreciated even though pain may exert an increasingly negative impact on patient quality...
The consequences of pain in early onset Parkinson's disease (EOPD) remain under appreciated even though pain may exert an increasingly negative impact on patient quality of life as motor and non-motor symptoms worsen. In this prospective study, we investigate the prevalence and severity of pain in 135 Vietnamese patients with EOPD from three medical centers using the King's PD Pain Scale (KPPS), the Mini Mental Status Exam (MMSE), the Unified Parkinson's Disease Rating Scale (UPDRS) and the Non-Motor Symptoms Scale (NMSS). Pain was reported by 79.3%. The most common subtype of pain was musculoskeletal (70.1%), followed by nocturnal (43.9%), radicular (43.0%), chronic (42.1%), fluctuation-related (34.6%) and orofacial pain (16.8%). Most patients (74.8%) experienced more than one pain subtype. Fluctuation-related pain and orofacial pain were significantly more prevalent among patients with higher Hoehn & Yahr (H&Y) stages (3-5) versus lower H&Y stages (1-2). Pain subtype and severity were not significantly related to gender or age of PD onset. Patients with H&Y stages 3-5 had statistically significantly higher KPPS scores for fluctuation-related pain (p = 0.018) and radicular pain (p = 0.026). Independent associations were found between pain severity and age (p = 0.028), depression severity (p = 0.018), perceptual problems/hallucinations (p = 0.033) and sexual function (p = 0.024). Patients with depression and higher H&Y stages (3-5) had statistically significantly higher mean KPPS scores versus patients without depression and at lower H&Y stages (1-2). Pain may be more common and severe in EOPD patients than previously appreciated. Older age, depression, perceptual problems/hallucinations and sexual dysfunction were independently associated with higher pain severity.
Topics: Humans; Parkinson Disease; Pain Measurement; Prospective Studies; Quality of Life; Facial Pain; Hallucinations
PubMed: 38043181
DOI: 10.1016/j.jns.2023.122784 -
Schizophrenia Research. Cognition Dec 2023Increasing evidence of a common neurodevelopmental etiology between schizophrenia and developmental dyslexia suggests that neurocognitive functions, such as reading, may...
Increasing evidence of a common neurodevelopmental etiology between schizophrenia and developmental dyslexia suggests that neurocognitive functions, such as reading, may be similarly disrupted. However, direct comparisons of reading performance in these disorders have yet to be conducted. To address this gap in the literature, we employed a gaze-contingent moving window paradigm to examine sentence-level reading fluency and perceptual span (breadth of parafoveal processing) in adults with schizophrenia (dataset from Whitford et al., 2013) and psychiatrically healthy adults with dyslexia (newly collected dataset). We found that the schizophrenia and dyslexia groups exhibited similar reductions in sentence-level reading fluency (e.g., slower reading rates, more regressions) compared to matched controls. Similar reductions were also found for standardized language/reading and executive functioning measures. However, despite these reductions, the dyslexia group exhibited a larger perceptual span (greater parafoveal processing) than the schizophrenia group, potentially reflecting a disruption in normal foveal-parafoveal processing dynamics. Taken together, our findings suggest that reading and reading-related functions are largely similarly disrupted in schizophrenia and dyslexia, providing additional support for a common neurodevelopmental etiology.
PubMed: 37435364
DOI: 10.1016/j.scog.2023.100289 -
Journal of Clinical Medicine Nov 2023Previous studies have identified areas of cognitive weakness in children diagnosed with Specific Learning Disorder (SLD), in the areas of working memory and processing...
BACKGROUND
Previous studies have identified areas of cognitive weakness in children diagnosed with Specific Learning Disorder (SLD), in the areas of working memory and processing speed in particular. In adulthood, this literature is still scant, and no studies have compared the cognitive profile of university students with dyslexia (DD) with that of students with Mixed-type SLD.
METHOD
Thus, in this study, the WAIS-IV was used to examine the cognitive functioning of three groups of university students: students with DD, with Mixed-type SLD, and typical students. Statistical analyses were performed to examine differences in WAIS-IV FSIQ, main, and additional indexes and subtests.
RESULTS
The results showed strengths in perceptual reasoning and good verbal comprehension abilities in both the DD and Mixed-type SLD group, with weaknesses in working memory and processing speed, leading to a pattern of a better General Ability Index (GAI) than Cognitive Proficiency Index (CPI) in both clinical groups. Thus, discrepancies between GAI and CPI, well documented in children with SLD, still manifest in adulthood in university students. Our findings also revealed worse cognitive performance in university students with mixed learning disorder relative to students with only a reading deficit.
CONCLUSIONS
The cognitive features and distinctive subtest profiles that emerged should guide the assessment and the definitions of intervention programs, special educational needs, and strategies of compensation.
PubMed: 38002724
DOI: 10.3390/jcm12227113 -
Journal of Vision Sep 2023The double-drift illusion has two unique characteristics: The error between the perceived and physical position of the stimulus grows over time, and saccades to the...
The double-drift illusion has two unique characteristics: The error between the perceived and physical position of the stimulus grows over time, and saccades to the moving target land much closer to the physical than the perceived location. These results suggest that the perceptual and saccade targeting systems integrate visual information over different time scales. Functional imaging studies in humans have revealed several potential cortical areas of interest, including the prefrontal cortex. However, we currently lack an animal model to study the neural mechanisms of location perception that underlie the double-drift illusion. To fill this gap, we trained two marmoset monkeys to fixate and then saccade to the double-drift stimulus. In line with human observers for radial double-drift trajectories with fast internal motion, we find that saccade endpoints show a significant bias that is, nevertheless, smaller than the bias seen in human perceptual reports. This bias is modulated by changes in the external and internal speeds of the stimulus. These results demonstrate that the saccade targeting system of the marmoset monkey is influenced by the double-drift illusion.
Topics: Animals; Humans; Callithrix; Illusions; Bias; Models, Animal; Motion
PubMed: 37676672
DOI: 10.1167/jov.23.10.4