3-Acetylpyridine-induced ataxic-like motor impairments are associated with plastic changes in the Purkinje cells of the rat cerebellum.

Ataxias are characterized by aberrant movement patterns closely related to cerebellar dysfunction. Purkinje cell axons are the sole outputs from the cerebellar cortex, and dysfunctional activity of Purkinje cells has been associated with ataxic movements. However, the synaptic characteristics of Purkinje cells in cases of ataxia are not yet well understood. The nicotinamide antagonist 3-acethylpyridine (3-AP) selectively destroys inferior olivary nucleus neurons so it is widely used to induce cerebellar ataxia. Five days after 3-AP treatment (65mg/kg) in adult male Sprague-Dawley rats, motor incoordination was revealed through BBB and Rotarod testing. In addition, in Purkinje cells from lobules V-VII of the cerebellar vermis studied by the Golgi method, the density of dendritic spines decreased, especially the thin and mushroom types. Western blot analysis showed a decrease in AMPA and PSD-95 content with an increase of the α-catenin protein, while GAD-67 and synaptophysin were unchanged. Findings suggest a limited capacity of Purkinje cells to acquire and consolidate afferent excitatory inputs and an aberrant, rigid profile in the movement-related output patterns of Purkinje neurons that likely contributes to the motor-related impairments characteristic of cerebellar ataxias.

Rechallenge in idiosyncratic drug-induced liver injury: An analysis of cases in two large prospective registries according to existing definitions.

INTRODUCTION: Data on positive rechallenge in idiosyncratic drug-induced liver injury (DILI) are scarce. We aim to analyse the clinical presentation, outcome and drugs associated with positive rechallenge in two DILI registries. METHODS: Cases from the Spanish and Latin American DILI registries were included. Demographics, clinical characteristics and outcome of cases with positive rechallenge according to CIOMS/RUCAM and current definitions were analysed. RESULTS: Of 1418 patients with idiosyncratic DILI, 58 cases had positive rechallenge (4.1%). Patients with positive rechallenge had shorter duration of therapy (p=0.001) and latency (p=0.003). In patients with rechallenge, aspartate transaminase levels were increased (p=0.026) and showed a prolonged time to recovery (p=0.020), albeit no differences were seen in terms of fatal outcomes. The main drug implicated in rechallenge was amoxicillin-clavulanate (17%). The majority of re-exposure events were unintentional (71%). Using both existing definitions of positive rechallenge, there were four cases which exclusively fulfilled the current criteria and five which only meet the historical definition. All cases of positive rechallenge, irrespective of the pattern of damage, fulfilled the criteria of either alanine transaminase (ALT) ≥3 times the upper limit of normal (ULN) and/or alkaline phosphatase (ALP) ≥2 times ULN. CONCLUSIONS: Episodes of rechallenge were characterised by shorter duration of therapy and latency, and longer time to resolution, but did not show an increased incidence of fatal outcome. Based on our findings, ALT ≥3 times ULN and/or ALP ≥2 times ULN, regardless of the pattern of damage, is proposed as a new definition of rechallenge in DILI.

Clinicoradiological application of the use of spectral cranial computed tomography in the management of acute ischemic stroke after mechanical thrombectomy. / Aplicación clinicorradiológica del uso de la tomografía computarizada craneal de tecnología espectral en el manejo del ictus isquémico agudo tras trombectomía mecánica.

INTRODUCTION: Acute ischemic stroke is one of the leading global causes of morbidity and mortality. Mechanical thrombectomy has improved the functional prognosis of this condition; however, hemorrhagic transformation is a common complication. Spectral computed tomography (CT) imaging, as a neuroimaging control test, distinguishes contrast extravasation from hemorrhagic transformation due to the differential behavior of materials at dual energy levels. This distinction is valuable in its clinical therapeutic management. MATERIAL AND METHODS: A single-center, observational, retrospective study was conducted in which the presence of various clinical, radiological, and therapeutic variables in patients with acute ischemic stroke treated with mechanical thrombectomy at our hospital between July 2022 and March 2023 was investigated using access to a dissociated database and medical records. RESULTS: Out of 155 included patients, spectral cranial CT was performed in 63, and conventional cranial CT in 75. In the spectral CT group, 21 hyperdense images were detected, compared to 28 in the conventional CT group. In 42.8% of cases where hyperdensity was detected in the conventional CT group, it was not possible to distinguish between contrast extravasation and hemorrhagic transformation, in contrast to the 4.8% in the spectral CT group (p < 0.001). CONCLUSIONS: Spectral CT provides high diagnostic confidence to the radiologist in identifying the type of detected hyperdensity, thereby offering significant therapeutic confidence to the neurologist in early resuming anticoagulation therapy.

TITLE: Aplicación clinicorradiológica del uso de la tomografía computarizada craneal de tecnología espectral en el manejo del ictus isquémico agudo tras trombectomía mecánica.Introducción. El ictus isquémico agudo es una de las principales causas globales de morbimortalidad. La trombectomía mecánica ha mejorado el pronóstico funcional de esta patología; sin embargo, la transformación hemorrágica es una complicación frecuente. La tomografía computarizada (TC) de tecnología espectral, como prueba de neuroimagen de control, diferencia la extravasación de contraste de la transformación hemorrágica gracias al diferente comportamiento de los materiales a la energía dual, y esta distinción es de utilidad en su manejo clinicoterapéutico. Material y métodos. Estudio unicéntrico, observacional y retrospectivo, en el cual se investigó, mediante el acceso a una base de datos disociada y a la historia clínica, la presencia de una serie de variables clínicas, radiológicas y terapéuticas en los pacientes con ictus isquémico agudo que fueron tratados con trombectomía mecánica en nuestro hospital entre julio de 2022 y marzo de 2023. Resultados. De los 155 pacientes incluidos, se realizó una TC craneal espectral en 63 y convencional en 75. En el grupo de TC espectral se detectaron 21 imágenes hiperdensas y en el grupo de TC convencional fueron 28. En el 42,8% de los casos en los que se detectó una hiperdensidad en el grupo de TC convencional no se pudo distinguir entre extravasación de contraste y transformación hemorrágica, en comparación con el 4,8% del grupo de TC espectral (p < 0,001). Conclusiones. La TC espectral confiere una gran confianza diagnóstica al radiólogo para establecer el tipo de hiperdensidad detectada y, por ello, proporciona también una gran confianza terapéutica al neurólogo para reiniciar precozmente la anticoagulación.

Liver injury due to COVID-19 in critically ill adult patients. A retrospective study.

INTRODUCTION AND AIM: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged, causing the current pandemic of acute respiratory disease known as COVID-19. Liver injury due to COVID-19 is defined as any liver injury occurring during the course of the disease and treatment of patients with COVID-19, with or without liver disease. The incidence of elevated liver transaminases, alanine aminotransferase (ALT) and aspartate aminotransferase (AST), ranges from 2.5 to 76.3%. The aim of the present study was to describe the hepatic biochemical abnormalities, after a SARS-CoV-2-positive polymerase chain reaction (PCR) test, and the mortality rate in critically ill patients. MATERIALS AND METHODS: A retrospective study was conducted that included 70 patients seen at a private hospital in Mexico City, within the time frame of February-December 2021. Median patient age was 44.5 years (range: 37-57.2) and 43 (61.4%) of the patients were men. Liver function tests were performed on the patients at hospital admission. RESULTS: Gamma glutamyl transferase (GGT) levels were elevated (p = 0.032), as were those of AST (p = 0.011) and ALT (p = 0.021). The patients were stratified into age groups: 18-35, 36-50, and > 50 years of age. The 18 to 35-year-olds had the highest liver enzyme levels and transaminase levels were higher, the younger the patient. Due to the low mortality rate (one patient whose death did not coincide with a hepatic cause), the multivariate analysis showed an R2 association of 0.689, explained by AST, GGT, and C-reactive protein levels. CONCLUSIONS: Despite the increase in transaminases in our study population during the course of COVID-19, there was no increase in mortality. Nevertheless, hospitalized patient progression should be continuously followed.

Linear energy transfer (LET) distribution outside small radiotherapy field edges produced by 6 MV X-rays.

In modern radiotherapy with photons, the absorbed dose outside the radiation field is generally investigated. But it is well known that the biological damage depends not only on the absorbed dose but also on LET. This work investigated the dose-average LET (LΔ,D) outside several small radiotherapy fields to provide information that can help for better evaluating the biological effect in organs at risk close to the tumour volume. The electron fluences produced in liquid water by a 6 MV X-rays Varian iX linac were calculated using the EGSnrc Monte Carlo code. With the electron spectra, LΔ,D calculations were made for eight open small square fields and the reference field at water depths of 0.15 cm, 1.35 cm, 9.85 cm and 19.85 cm and several off-axis distances. The variation of LΔ,D from the centre of the beam to 2 cm outside the field's edge depends on the field size and water depth. Using radiobiological data reported in the literature for chromosomal aberrations as an endpoint for the induction of dicentrics determined in Human Lymphocytes, we estimated the maximum low-dose relative biological effectiveness, (RBEM) finding an increase of up to 100% from the centre of the beam to 2 cm from the field's edge.

Sonidegib as a Locally Advanced Basal Cell Carcinoma Therapy in Real-life Clinical Setting: A National Multicentre Study. / [Artículo traducido] Sonidegib para el tratamiento del carcinoma basocelular avanzado en práctica clínica real: estudio nacional multicéntrico.

BACKGROUND: Basal cell carcinoma (BCC) is the most prevalent cancer. A minority of BCCs have an aggressive behaviour (laBCC) and may require hedgehog pathway inhibitors such as sonidegib as its treatment. OBJECTIVE: To describe the use of sonidegib in a large number of patients and provide more data on its real-life efficacy and safety profile. METHODS: We conducted a retrospective and multicentric study that included patients treated with sonidegib. Epidemiological, effectiveness and safety data were collected. RESULTS: A total of 82 patients with a mean age of 73.9 years were included. Ten patients had Gorlin syndrome. Median treatment duration was 6 months. Median follow-up duration was 34.2 months. Globally, 81.7% of the patients showed clinical improvement (52.4% partial response and 29.3% complete response), 12.2% clinical stability and 6.1% disease progression. There was no statistically significant difference in clinical improvement between the 24 h and 48 h sonidegib posology. After 6 months of treatment, 48.8% of the patients discontinued sonidegib. Prior vismodegib treatment and recurrent primary BCC were associated with a poorer response to sonidegib. At 6 months of treatment, 68.3% of the patients experienced at least one adverse effect. CONCLUSION: Sonidegib shows good effectiveness and acceptable safety profile in usual clinical practice.

Sonidegib as a Locally Advanced Basal Cell Carcinoma Therapy in Real-life Clinical Setting: A National Multicentre Study.

BACKGROUND: Basal cell carcinoma (BCC) is the most prevalent cancer. A minority of BCCs have an aggressive behaviour (laBCC) and may require hedgehog pathway inhibitors such as sonidegib as its treatment. OBJECTIVE: To describe the use of sonidegib in a large number of patients and provide more data on its real-life efficacy and safety profile. METHODS: We conducted a retrospective and multicentric study that included patients treated with sonidegib. Epidemiological, effectiveness and safety data were collected. RESULTS: A total of 82 patients with a mean age of 73.9 years were included. Ten patients had Gorlin syndrome. Median treatment duration was 6 months. Median follow-up duration was 34.2 months. Globally, 81.7% of the patients showed clinical improvement (52.4% partial response and 29.3% complete response), 12.2% clinical stability and 6.1% disease progression. There was no statistically significant difference in clinical improvement between the 24h and 48h sonidegib posology. After 6 months of treatment, 48.8% of the patients discontinued sonidegib. Prior vismodegib treatment and recurrent primary BCC were associated with a poorer response to sonidegib. At 6 months of treatment, 68.3% of the patients experienced at least one adverse effect. CONCLUSION: Sonidegib shows good effectiveness and acceptable safety profile in usual clinical practice.

[Liver injury due to COVID-19 in critically ill adult patients. A retrospective study]. / Lesión hepática por COVID-19 en pacientes adultos criticamente enfermos. Estudio retrospectivo.

INTRODUCTION AND AIM: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged, causing the current pandemic of acute respiratory disease known as COVID-19. Liver injury due to COVID-19 is defined as any liver injury occurring during the course of the disease and treatment of patients with COVID-19, with or without liver disease. The incidence of elevated liver transaminases, alanine aminotransferase (ALT) and aspartate aminotransferase (AST), ranges from 2.5 to 76.3%. The aim of the present study was to describe the hepatic biochemical abnormalities, after a SARS-CoV-2-positive polymerase chain reaction (PCR) test, and the mortality rate in critically ill patients. MATERIALS AND METHODS: A retrospective study was conducted that included 70 patients seen at a private hospital in Mexico City, within the time frame of February-December 2021. Median patient age was 44.5 years (range: 37-57.2) and 43 (61.4%) of the patients were men. Liver function tests were performed on the patients at hospital admission. RESULTS: Gamma glutamyl transferase (GGT) levels were elevated (p = 0.032), as were those of AST (p = 0.011) and ALT (p = 0.021). The patients were stratified into age groups: 18-35, 36-50, and > 50 years of age. The 18 to 35-year-olds had the highest liver enzyme levels and transaminase levels were higher, the younger the patient. Due to the low mortality rate (one patient whose death did not coincide with a hepatic cause), the multivariate analysis showed an R2 association of 0.689, explained by AST, GGT, and C-reactive protein levels. CONCLUSIONS: Despite the increase in transaminases in our study population during the course of COVID-19, there was no increase in mortality. Nevertheless, hospitalized patient progression should be continuously followed.

Fractalkine/CX3CR1-Dependent Modulation of Synaptic and Network Plasticity in Health and Disease.

CX3CR1 is a G protein-coupled receptor that is expressed exclusively by microglia within the brain parenchyma. The only known physiological CX3CR1 ligand is the chemokine fractalkine (FKN), which is constitutively expressed in neuronal cell membranes and tonically released by them. Through its key role in microglia-neuron communication, the FKN/CX3CR1 axis regulates microglial state, neuronal survival, synaptic plasticity, and a variety of synaptic functions, as well as neuronal excitability via cytokine release modulation, chemotaxis, and phagocytosis. Thus, the absence of CX3CR1 or any failure in the FKN/CX3CR1 axis has been linked to alterations in different brain functions, including changes in synaptic and network plasticity in structures such as the hippocampus, cortex, brainstem, and spinal cord. Since synaptic plasticity is a basic phenomenon in neural circuit integration and adjustment, here, we will review its modulation by the FKN/CX3CR1 axis in diverse brain circuits and its impact on brain function and adaptation in health and disease.

Ultrasound-guided percutaneous cryoneurolysis for management of acute sternal fracture pain.

Background: Establishing adequate analgesia for rib and sternal fractures remains a challenge due to the prolonged nature of the associated pain. Historically, cryoneurolysis has demonstrated beneficial in treating chronic pain, and the recent development of hand-held devices has allowed its functionality to expand into the management of acute pain. Case: We present a polytrauma patient with sternal and multiple rib fractures that underwent ultrasound-guided intercostal cryoneurolysis at bedside, resulting in significant analgesia lasting several weeks and improving mobilization. This is the first report of the utilization of cryoneurolysis to treat acute sternal fracture pain. Conclusion: The most common sternal fracture pattern is transverse which only requires treatment of four intercostal nerves, making cryoneurolysis feasible in trauma centers. This portable, minimally invasive, and low risk technique has the added benefits of reducing opioid requirements, decreasing length of hospital stay, and improving mobility in polytrauma patients.

African American Cancer Survivors' Perspectives on Cancer Clinical Trial Participation in a Safety-Net Hospital: Considering the Role of the Social Determinants of Health.

Although there has been an increase focus on recruitment of minority populations at safety-net hospitals into cancer clinical trials, there is still a paucity of research exploring minority participation in cancer clinical trials at safety-net settings. The study utilized a multi-level, qualitative approach to assess the clinical and non-clinical facilitators and barriers to African American participation in cancer clinical trials at a safety-net hospital. From June 2018 to July 2019, cancer survivors (n = 25) were recruited from a cancer center at a safety-net hospital in the southeastern USA and participated in a 60-min focus group. Data was coded and analyzed to identify the most prominent themes. Most participants were female (78%), with a mean age of 56 years. The majority were diagnosed with breast cancer (68%) and disabled or unemployed (55%). Major themes identified were (1) lack of understanding of cancer clinical trials, (2) perceptions and fears of cancer clinical trials, and (3) preferred role and characteristics of patient navigator. The barriers and facilitators to enrollment in cancer clinical trials were more pronounced in the safety-net setting, given the overdue burden of social determinants of health. Study findings yield important insights and essential practices for recruiting and engaging underrepresented Black cancer patients into cancer clinical trials, specifically for safety-net settings. Including patient navigators may help traverse potential barriers to cancer clinical trial participation and will allow for the attention to social determinants of health, and ultimately increase the number of African Americans participating in cancer clinical trials.

Feasibility of unilateral hemilaminectomy utilizing a Williams retractor for the resection of intradural-extramedullary spinal neoplasms.

BACKGROUND: While open approaches have historically been used in the surgical treatment of intradural-extramedullary spine tumors, minimally-invasive surgical (MIS) techniques are frequently applied to minimize post-operative complications associated with open surgery. Tubular retractor systems in particular have been employed in combination with the unilateral hemilaminectomy (UHL) approach. Here we describe the use of a Williams retractor as a safe and effective minimally-invasive alternative to tubular retractor systems with similar post-operative outcomes. METHODS: We retrospectively reviewed a cohort of eight patients who underwent unilateral hemilaminectomy using a Williams retractor for the minimally-invasive resection of intradural-extramedullary neoplasms at a large tertiary academic center from 2017 to 2019. Patient demographics, pathologic specimens, radiographic studies, and intraoperative parameters were collected and analyzed. RESULTS: In our series, gross total resection was achieved in all cases. Average operative time was 158±40minutes, the mean estimated blood loss (EBL) was 44.4±30.4mL, and mean length of stay was three days. All patients reported symptomatic improvement at follow-up as reported by Visual Analog Scale scores. CONCLUSION: A Williams retractor yields similar outcomes with respect to post-operative pain, operative time, and EBL as it maintains the advantages of the UHL approach in the resection of intradural-extramedullary spine tumors while enhancing feasibility and providing significant cost savings.

The flashfm approach for fine-mapping multiple quantitative traits.

Joint fine-mapping that leverages information between quantitative traits could improve accuracy and resolution over single-trait fine-mapping. Using summary statistics, flashfm (flexible and shared information fine-mapping) fine-maps signals for multiple traits, allowing for missing trait measurements and use of related individuals. In a Bayesian framework, prior model probabilities are formulated to favour model combinations that share causal variants to capitalise on information between traits. Simulation studies demonstrate that both approaches produce broadly equivalent results when traits have no shared causal variants. When traits share at least one causal variant, flashfm reduces the number of potential causal variants by 30% compared with single-trait fine-mapping. In a Ugandan cohort with 33 cardiometabolic traits, flashfm gave a 20% reduction in the total number of potential causal variants from single-trait fine-mapping. Here we show flashfm is computationally efficient and can easily be deployed across publicly available summary statistics for signals in up to six traits.

Accurate method for rapid biomass quantification based on specific absorbance of microalgae species with biofuel importance.

The development of microalgae culture technology has been an integral part to produce biomass feedstock to biofuel production. Due to this, numerous attempts have been made to improve some operational parameters of microalgae production. Despite this, specialized research in cell growth monitoring, considered as a fundamental parameter to achieve profitable applications of microalgae for biofuels production, presents some opportunity areas mainly related to the development of specific and accurate methodologies for growth monitoring. In this work, predictive models were developed through statistical tools that correlate a specific micro-algal absorbance with cell density measured by cell count (cells∙per ml), for three species of interest for biofuels production. The results allow the precise prediction of cell density through a logistic model based on spectrophotometry, valid for all the kinetics analysed. The adjusted determination coefficients ( r adj 2 ) for the developed models were 0·993, 0·995 and 0·994 for Dunaliella tertiolecta, Nannochloropsis oculata and Chaetoceros muelleri respectively. The results showed that the equations obtained here can be used with an extremely low error (≤2%) for all the cell growth ranges analysed, with low operational cost and high potential of automation. Finally, a user-friendly software was designed to give practical use to the developed predictive models.

[Adherence to pulmonary rehabilitation: An exploratory review]. / La adherencia a los tratamientos de rehabilitación pulmonar: revisión exploratoria.

Currently, several studies have identified low adherence to pulmonary rehabilitation in patients with COPD, despite the positive effects of the treatment. Patient adherence to pulmonary rehabilitation is affected by factors such as the absence of family support, and the presence of multiple comorbidities, respiratory distress, anxiety and depression. Given that there is no conclusive evidence about which of these factors are most influential in determining adherence to pulmonary rehabilitation in patients with COPD, we conducted this scoping review to analyse the available evidence on the factors influencing the adherence of patients with COPD to pulmonary rehabilitation programs (PRP). A wide literature search was carried out in Medline, Ovid, Science Direct, EMBASE, EBSCO and ISI-web of science, with prior definition of the selection criteria that included the factors associated with healthcare and adherence in patients with COPD in PRP. We used the adherence model proposed by the WHO as a conceptual framework. As a significant result, we found that factors in the dimension of illness (40%) and patient (30%) were the most frequently found dimensions in the studies, revealing that the design of pulmonary rehabilitation programs must take into account the specific needs of the patient. Further studies are needed to establish barriers and facilitators of adherence among COPD patients to PRP in the Colombian setting.

Scoping Review of Healthcare Literature on Mobile, Wearable, and Textile Sensing Technology for Continuous Monitoring.

Remote monitoring of health can reduce frequent hospitalisations, diminishing the burden on the healthcare system and cost to the community. Patient monitoring helps identify symptoms associated with diseases or disease-driven disorders, which makes it an essential element of medical diagnoses, clinical interventions, and rehabilitation treatments for severe medical conditions. This monitoring can be expensive and time-consuming and provide an incomplete picture of the state of the patient. In the last decade, there has been a significant increase in the adoption of mobile and wearable devices, along with the introduction of smart textile solutions that offer the possibility of continuous monitoring. These alternatives fuel a technology shift in healthcare, one that involves the continuous tracking and monitoring of individuals. This scoping review examines how mobile, wearable, and textile sensing technology have been permeating healthcare by offering alternate solutions to challenging issues, such as personalised prescriptions or home-based secondary prevention. To do so, we have selected 222 healthcare literature articles published from 2007 to 2019 and reviewed them following the PRISMA process under the schema of a scoping review framework. Overall, our findings show a recent increase in research on mobile sensing technology to address patient monitoring, reflected by 128 articles published in journals and 19 articles in conference proceedings between 2014 and 2019, which represents 57.65% and 8.55% respectively of all included articles.

Spinogenesis in spinal cord motor neurons following pharmacological lesions to the rat motor cortex. / Espinogénesis en motoneuronas de la médula espinal tras la lesión farmacológica de la corteza motora de ratas.

INTRODUCTION: Motor function is impaired in multiple neurological diseases associated with corticospinal tract degeneration. Motor impairment has been linked to plastic changes at both the presynaptic and postsynaptic levels. However, there is no evidence of changes in information transmission from the cortex to spinal motor neurons. METHODS: We used kainic acid to induce stereotactic lesions to the primary motor cortex of female adult rats. Fifteen days later, we evaluated motor function with the BBB scale and the rotarod and determined the density of thin, stubby, and mushroom spines of motor neurons from a thoracolumbar segment of the spinal cord. Spinophilin, synaptophysin, and ß iii-tubulin expression was also measured. RESULTS: Pharmacological lesions resulted in poor motor performance. Spine density and the proportion of thin and stubby spines were greater. We also observed increased expression of the 3 proteins analysed. CONCLUSION: The clinical symptoms of neurological damage secondary to Wallerian degeneration of the corticospinal tract are associated with spontaneous, compensatory plastic changes at the synaptic level. Based on these findings, spontaneous plasticity is a factor to consider when designing more efficient strategies in the early phase of rehabilitation.

One-year prognosis of non-traumatic cortical subarachnoid haemorrhage: A prospective series of 34 patients. / Pronóstico al año de la hemorragia subaracnoidea cortical no traumática: Serie prospectiva de 34 pacientes.

INTRODUCTION: Cortical subarachnoid haemorrhage (cSAH) has multiple aetiologies. No prospective study has reported the long-term progression of the condition. The objective of this study is to describe the clinical and aetiological characteristics of patients with cSAH and to gain insight into prognosis. METHODS: We performed a prospective, observational, multi-centre study. Data on clinical and radiological variables were collected; during a one-year follow-up period, we recorded data on mortality, dependence, rebleeding, and the appearance of dementia. RESULTS: The study included 34 patients (mean age, 68.3 years; range, 27-89). The most frequent symptoms were headache and focal neurological deficits, which were frequently transient and recurrent. CT scans returned pathological findings in 28 patients (85%). Brain MRI scans were performed in 30 patients (88%), revealing acute ischaemia in 10 (29%), old haemorrhage in 7 (21%), and superficial siderosis in 2 (6%). Aetiology was identified in 26 patients (76.5%): causes were cerebral amyloid angiopathy in 8, ischaemic stroke in 5, vasculitis in 4, reversible posterior encephalopathy in 2, venous thrombosis in 2, reversible cerebral vasoconstriction syndrome in 2, carotid occlusion in 1, Marfan syndrome in 1, and meningeal carcinomatosis in 1. Three patients died during follow-up (2 due to causes related to the cause of cSAH). Three patients developed dementia, 3 had lobar haemorrhages, and one had a second cSAH. CONCLUSIONS: The most frequent causes of cSAH in our series were cerebral amyloid angiopathy, ischaemic stroke, and vasculitis. This type of haemorrhage has a worse prognosis than other non-aneurysmal cSAH. There are numerous possible causes, and prognosis depends on the aetiology. In elderly patients, intracranial haemorrhage is frequently associated with cognitive impairment.

Plastic changes to dendritic spines in the cerebellar and prefrontal cortices underlie the decline in motor coordination and working memory during successful aging.

Old age is the last stage of life and by taking a multidimensional view of aging, Neuroscientists have been able to characterize pathological or successful aging. Psychomotor and cognitive performance are recognized as two major domains of successful aging, with a loss of motor coordination and working memory deficits two of the most characteristic features of elderly people. Dendritic spines in both the cerebellar and prefrontal cortices diminish in aging, yet the plastic changes in dendritic spines have not been related to behavioral performance neither the changes in the cerebellar or prefrontal cortices. As such, motor coordination and visuospatial working memory (vsWM) was evaluated here in aged, 22-month-old rats, calculating the density of spines and the proportion of the different types of spines. These animals performed erratically and slowly in a motor coordination-related paradigm, and the vsWM was resolved deficiently. Spine density was reduced in aged animals, and the proportional density of each of the spine types studied diminished in both the brain regions studied. The loss of dendritic spines and particularly, the changes in the proportional density of the different spine types could underlie, at least in part, the behavioral deficits observed during aging. To our knowledge, this is the first study of the plastic changes in different dendritic spine types that might underlie the behavioral alterations in motor and cognitive abilities associated with aging. Further neurochemical and molecular studies will help better understand the functional significance of the plastic changes to dendritic spines in both successful and pathological aging.