Cerebellar Syndromes: A Medical Student Guide

The cerebellum is central to normal motor function and co-ordination, and can be frequently affected in a number of common disease processes. However, medical student teaching relating to cerebellar anatomy and pathology is lacking, leaving many graduates with a significant knowledge gap. Junior doctors need to be able to recognize ‘cerebellar syndromes’ on presentation to hospitals, and to identify and manage reversible causes rapidly and effectively. After review of relevant literature, a simple approach to the functional anatomy and practical classifications of common cerebellar pathology is presented here, with a focus on symptoms, signs and examination techniques essential to medical school final exams

Assessment of visually guided reaching in prodromal Alzheimer’s disease: a cross-sectional study protocol

Introduction Recent evidence has implicated the precuneus of the medial parietal lobe as one of the first brain areas to show pathological changes in Alzheimer's disease (AD). Damage to the precuneus through focal brain injury is associated with impaired visually guided reaching, particularly for objects in peripheral vision. This raises the hypothesis that peripheral misreaching may be detectable in patients with prodromal AD. The aim of this study is to assess the frequency and severity of peripheral misreaching in patients with mild cognitive impairment (MCI) and AD. Methods and analysis Patients presenting with amnestic MCI, mild-to-moderate AD and healthy older-adult controls will be tested (target N=24 per group). Peripheral misreaching will be assessed using two set-ups: A tablet-based task of lateral reaching and motion-tracked radial reaching (in depth). There are two versions of each task, one where participants can look directly at targets (free reaching), another wheren they must maintain central fixation (peripheral reaching). All tasks will be conducted first on their dominant, and then their non-dominant side. For each combination of task and side, a Peripheral Misreaching Index (PMI) will be calculated as the increase in absolute reaching error between free and peripheral reaching. Each patient will be classified as showing peripheral misreaching if their PMI is significantly abnormal, by comparison to control performance, on either side of space. We will then test whether the frequency of peripheral misreaching exceeds the chance level in each patient group and compare the overall severity of misreaching between groups. Ethics and dissemination Ethical approval was provided by the National Health Service (NHS) East of England, Cambridge Central Research Ethics Committee (REC 19/EE/0170). The results of this study will be published in a peer-reviewed journal and presented at academic conferences

The Edinburgh Cognitive and Behavioural ALS Screen:Relationship to age, education, IQ and the Addenbrooke’s Cognitive Examination-III

The Edinburgh Cognitive and Behavioral ALS Screen (ECAS) was developed to assess cognitive and behavioral changes common in Amyotrophic Lateral Sclerosis and other diseases affecting motor functions. It focuses on domains typically affected by the frontotemporal syndrome (executive and language functions, fluency and behavior), but assesses also memory and visuospatial functions. Objectives: (A) To investigate the relationship between the ECAS and the Addenbrooke’s Cognitive Examination (ACE-III). (B) To investigate the effects of age, education, and IQ on the ECAS and create appropriate cutoff scores to determine abnormality. Methods: (A) 57 healthy participants (aged 35–80) were assessed with the ECAS, the Wechsler Abbreviated Scale of Intelligence (WASI-II), and the ACE-III. (B) 80 healthy participants (aged 51–80) were divided into four groups according to age and education; and were tested with the ECAS and the WASI-II. Results: The ECAS and the ACE-III have a good convergent validity with a significant correlation. Regression analysis revealed that IQ, followed by age, were the strongest predictors of the total ECAS score. IQ predicted 24% of the ECAS and 46% of the ACE-III variance. Education was not a significant predictor over and above IQ for both the ECAS and the ACE-III. Abnormality cutoff scores adjusted for age and education are presented. Conclusions: The ECAS shows good convergent validity with the ACE-III, but is less influenced by intelligence and presents less ceiling effects. The inclusion of an executive function assessment and behavioral interview in the ECAS makes it particularly useful for the assessment of frontal lobe disorders

Variant Creutzfeldt-Jakob disease in UK children after 27 years of active prospective surveillance

OBJECTIVE: To determine whether any children in the UK had variant Creutzfeldt-Jakob disease (vCJD).DESIGN: This active prospective epidemiological study used the British Paediatric Surveillance Unit, asking UK paediatricians to notify all childhood cases of progressive intellectual and neurological deterioration (PIND), a group that would include all cases of vCJD. Clinical data were obtained by questionnaire or via a site visit. An independent expert group classified the cases. If vCJD was suspected, referral to the National Creutzfeldt-Jakob Disease Research and Surveillance Unit was recommended.RESULTS: Between May 1997 and April 2024 (27 years), 5222 children were notified. There were four groups. (1) 2540 were 'not cases'-they did not meet the case definition or there were notification errors. (2) 2367 had a known underlying diagnosis other than vCJD; the group contained more than 220 different diseases. (3) 309 had no diagnosis to explain their deterioration; there was evidence that none of these cases had vCJD. (4) There were six cases of vCJD: two males and four females. They developed symptoms between 1998 and 2000, aged 12-15 years, and the last two died in 2003. Their clinical features were similar to those of adults. Four were classified as definite vCJD and two as probable vCJD.CONCLUSIONS: This study has provided unique data about neurodegenerative diseases in UK children. There is no reliable vCJD screening test; so for 27 years, the PIND study has provided reassurance that childhood vCJD cases were not missed. New vCJD cases with the methionine/valine genotype could appear.</p

Nonlinear Hydrodynamics from Flow of Retarded Green's Function

We study the radial flow of retarded Green's function of energy-momentum tensor and $R$-current of dual gauge theory in presence of generic higher derivative terms in bulk Lagrangian. These are first order non-linear Riccati equations. We solve these flow equations analytically and obtain second order transport coefficients of boundary plasma. This way of computing transport coefficients has an advantage over usual Kubo approach. The non-linear equation turns out to be a linear first order equation when we study the Green's function perturbatively in momentum. We consider several examples including $Weyl^4$ term and generic four derivative terms in bulk. We also study the flow equations for $R$-charged black holes and obtain exact expressions for second order transport coefficients for dual plasma in presence of arbitrary chemical potentials. Finally we obtain higher derivative corrections to second order transport coefficients of boundary theory dual to five dimensional gauge supergravity.Comment: Version 2, reference added, typos correcte

The relationship between social cognitive processes and behavior changes in people with amnestic Mild Cognitive Impairment or dementia using the Edinburgh Social Cognition Test (ESCoT)

Objectives: People with amnestic Mild Cognitive Impairment (aMCI) or dementia often exhibit a decline in their social abilities, but few tests of social cognition exist that are suitable for clinical use. Moreover, the relationship between changes in behaviour and impairments in social cognition is poorly understood. We examined the utility of the Edinburgh Social Cognition Test (ESCoT) in people with aMCI/dementia and explored associations between social cognition performance and behaviour changes. Methods: We administered the ESCoT and two established social cognition tests (Reading the Mind in the Eyes; RME and the Social Norms Questionnaire; SNQ) to 28 people with aMCI or dementia and 28 age and sex matched cognitively healthy controls. Behaviour change was measured using a semi-structured interview which assesses behavioural abnormalities found in frontotemporal dementia. Results: People with aMCI/dementia were impaired on the ESCoT affective ToM, ESCoT total score and the RME. Behaviour changes in the domains of apathy, loss of sympathy/empathy, perseveration, and psychotic symptoms were associated with poorer affective ToM scores. Disinhibition, loss of sympathy/empathy and hyperorality or altered food preferences were associated with cognitive ToM. All behaviours were significantly associated with poorer performance on ESCoT total score, but not the RME or SNQ.Conclusion: The ESCoT was sensitive to social cognition impairments in people with aMCI/dementia and it relates to behaviour change in aMCI/dementia unlike established tests. Different subtests of the ESCoT were related to different behaviour changes. These findings suggest that the ESCoT may be a clinically valuable tool when examining social cognition

Multidimensional apathy in behavioural variant frontotemporal dementia, primary progressive aphasia and Alzheimer’s disease

Apathy is prevalent in dementia, such as behavioral variant frontotemporal dementia (bvFTD), primary progressive aphasia (PPA), and Alzheimer disease (AD). As a multidimensional construct, it can be assessed and subsumed under a Dimensional Apathy Framework. A consistent apathy profile in bvFTD and PPA has yet to be established. The aim was to explore apathy profiles and awareness in bvFTD, PPA, and AD. A total of 12 patients with bvFTD, 12 patients with PPA, 28 patients with AD, and 20 matched controls, as well as their informants/carers, were recruited. All participants completed the Dimensional Apathy Scale (DAS), assessing executive, emotional, and initiation apathy subtypes, a 1-dimensional apathy measure, depression measure, and functional and cognitive screens. Apathy subtype awareness was determined through DAS informant/carer and self-rating discrepancy. Apathy profile comparison showed patients with bvFTD had significantly higher emotional apathy than patients with AD (P <.01) and significantly higher apathy over all subtypes than patients with PPA (Ps <.05). Additionally, patients with bvFTD had significantly lower awareness for emotional apathy (P <.01) when compared to patients with AD and PPA. All patient groups had significant global apathy over all subtypes compared to controls. The emergent apathy profile for bvFTD seems to be emotional apathy (indifference or emotional/affective neutrality), with lower self-awareness in this subtype. Further, lower self-awareness for executive apathy (lack of motivation for planning, organization, or attention) differentiates bvFTD from PPA. Future research should investigate the cognitive and neural correlates as well as the practical impact of apathy subtypes

Non-Invasive RF Technique for Detecting Different Stages of Alzheimer’s Disease and Imaging Beta-Amyloid Plaques and Tau Tangles in the Brain

This paper describes a novel approach of detecting different stages of Alzheimer’s disease (AD) and imaging beta-amyloid plaques and tau tangles in the brain using RF sensors. Dielectric measurements were obtained from grey matter and white matter regions of brain tissues with severe AD pathology at a frequency range of 200 MHz to 3 GHz using a vector network analyzer and dielectric probe. Computational models were created on CST Microwave Suite using a realistic head model and the measured dielectric properties to represent affected brain regions at different stages of AD. Simulations were carried out to test the performance of the RF sensors. Experiments were performed using textile-based RF sensors on fabricated phantoms, representing a human brain with different volumes of AD-affected brain tissues. Experimental data was collected from the sensors and processed in an imaging algorithm to reconstruct images of the affected areas in the brain. Measured dielectric properties in brain tissues with AD pathology were found to be different from healthy human brain tissues. Simulation and experimental results indicated a correlated shift in the captured reflection coefficient data from RF sensors as the amount of affected brain regions increased. Finally, images reconstructed from the imaging algorithm successfully highlighted areas of the brain affected by plaques and tangles as a result of AD. The results from this study show that RF sensing can be used to identify areas of the brain affected by AD pathology. This provides a promising new non-invasive technique for monitoring the progression of AD