Leading scientific journals in fields such as medicine, biology and sociology repeatedly publish articles and editorials claiming that a large percentage of doctors do not understand the basics of statistical analysis, which increases the risk of errors in interpreting data, makes them more vulnerable to misinformation and reduces the effectiveness of research. This problem extends throughout their careers and is largely due to the poor training they receive in statistics - a problem that is common in developed countries. As stated by H. Halle and S. Krauss, '90% of German university lecturers who regularly use the p-value in tests do not understand what that value actually measures'. It is important to note that the basic reasoning of statistical analysis is similar to what we do in our daily lives and that understanding the basic concepts of statistical analysis does not require any knowledge of mathematics. Contrary to what many researchers believe, the p-value of the test is not a 'mathematical index' that allows us to clearly conclude whether, for example, a drug is more effective than a placebo. The p-value of the test is simply a percentage.
Introduction: The primary objective of the core data set is to reduce heterogeneity and promote harmonization among data sources in EM, thereby reducing the time needed to execute real life data collection efforts. Recently, a group led by the Multiple Sclerosis Data Alliance has developed a core data set for collecting real-world data on multiple sclerosis (MS) globally. Our objective was to adapt this global data set to the needs of Latin America, so that it can be implemented by the registries already developed and in the process of development in the region.
Material and methods: A working group was formed regionally, the core data set created globally was adapted (translation process into Spanish, incorporation of regional variables and consensus on variables to be used). Consensus was obtained through the remote Delphi methodology of a round of questionnaires and remote discussion of the core data set variables.
Results: A total of 25 professionals from Latin America carried out the adaptation process between November 2022 and July 2023. Agreement was established on a core data set of nine categories and 45 variables, version 2023 to suggest its implementation in developed or developing registries, and MS cohorts in the region.
Conclusion: The core data set seeks to harmonize the variables collected by registries and cohorts in MS in Latin America in order to facilitate said collection and allow collaboration between sources. Its implementation will facilitate real life data collection and collaboration in the region.
Introduction: Ryanodine receptor type 1-related myopathies (RYR1-RM) represent the most prevalent category of congenital myopathies. The introduction of genetic techniques has shifted the diagnostic paradigm, suggesting the prioritization of molecular studies over biopsies. This study aims to explore the clinical and epidemiological characteristics of patients with RYR1 gene variants in a tertiary pediatric hospital, intending to enhance the understanding of the genotype-phenotype correlation in RYR1-RM.
Patients and methods: An observational, descriptive, and cross-sectional study was conducted on patients under 14 years old with myopathic symptoms and potentially pathogenic RYR1 gene variants from January 2013 to December 2023. Variables such as gender, age, motor development, genetic variants, inheritance pattern, and other manifestations were considered. All variables were tabulated against the genetic variant.
Results: Of the nine included patients, the estimated incidence was approximately 1 in 10,000 live births. The median age at diagnosis was six years, with significant phenotypic variability. Common symptoms such as weakness and delayed motor development were observed. Genetic variants affected the RYR1 gene diversely, including five previously undescribed variants. Muscle biopsy was performed in five patients, revealing central core myopathy in two, multiminicore in one, congenital fiber-type disproportion in one, and a nonspecific pattern in another.
Conclusions: RYR1-RM in our series exhibited phenotypic and involvement variability, with an incidence in our area of around 1 in 10,000 live births. Most cases were male, with dominant missense variants. We contribute five previously undescribed genetic variants.
Introduction: The Spanish neuroscientist Justo Gonzalo y Rodriguez-Leal (1910-1986) investigated the functional organisation of the cerebral cortex over more than four decades. His findings led him to formulate a neurophysiological theory based on the laws of nervous excitability, which he called brain dynamics. This paper presents in chronological order how the main ideas on which it is based arose.
Development: In 1939, Gonzalo observed the phenomena of dynamic action: asynchrony or disaggregation, facilitation and cerebral repercussion. This was followed by two principles: the cerebral effect of lesions according to their magnitude and position (1941), and spiral development of the sensory field (1947). At the same time, he characterised what he called the central syndrome of the cerebral cortex. In the 1950s he developed the concepts of the cortical gradient, similarity and allometry. In contrast to modular conceptions of the cerebral cortex, in which one region is responsible for one function, Gonzalo argued that 'cortical gradients provide the location of systems, while similarity and allometry reveal their functional mechanism.'
Conclusions: The theory of brain dynamics was established in two stages. The first (between 1938 and 1950) had an important clinical foundation, involving the observation of new phenomena and the formulation of new concepts. The second (between 1950 and 1960) included the introduction of more far-reaching concepts, such as the functional cortical gradient, and allometry laws based on a change of scale. Today, various authors believe that the concept of the gradient is crucial for understanding how the brain is organised.
Introduction: The objective is to produce an average brain activation mapping template in healthy children using functional magnetic resonance imaging (fMRI), with specific paradigms for activating inhibitory attention and working memory functions.
Subjects and methods: A nutritional and neuropsychological evaluation was performed on 87 right-handed children. The inclusion criteria were met by 30 children (15 boys and 15 girls) between 9 and 11 years old, who were studied with fMRI in two inhibitory attention tests (Go/No Go), with food cues, a working memory test (Continuous Performance Test Identical Pairs) and measurement of anatomical volumes. These data were subsequently processed with the FSL-v5 program, with a threshold of p < 0.05 (cluster-wise). The brain areas activated were located using a standard Montreal Neurological Institute brain template and the Harvard-Oxford structural cortical atlas.
Results: The inhibitory attention tests showed activation frontal areas predominantly on the right, and the cingulate, parietal and occipital areas, with preponderance in occipital areas in the food cues test. In the Continuous Performance Test-Identical Pairs test, activation was obtained predominantly in the occipital, frontal and parietal areas.
Conclusions: Brain activity mapping templates are obtained in healthy children with tests for inhibitory attention, food cues and working memory. The activation areas are mostly those reported in the literature. This provides baseline brain activation patterns for studying pathologies related to inhibitory attention, impulsivity and working memory.
Introduction: Mucopolysaccharidosis type III (MPS III), also known as Sanfilippo syndrome, is a lysosomal storage disease with progressive neurodegenerative features, predominantly affecting the central nervous system. Diagnosis is based on clinical features, with neurodevelopmental and neuropsychiatric alterations taking precedence, including over phenotype alterations. The disease is confirmed by biochemical analysis to identify the type of glycosaminoglycans present, enzyme assay and molecular genetic studies.
Case reports: A clinical description was performed for eight patients diagnosed with MPS III in Colombia. Their initial symptoms were related to developmental delay and behavioural disorders presenting between 3 and 8 years of age, associated in all cases with coarse facial features, thick eyebrows, hepatomegaly and progressive hearing loss. One of the patients presented cardiac anomalies; two presented focal epilepsy; and one presented optic atrophy. They all presented neuroimaging alterations, with evidence of parenchymal volume loss, corpus callosum atrophy and cortical thinning; the diagnosis was performed by biochemical glycosaminoglycan chromatography studies, and all patients have a confirmatory genetic study.
Conclusions: MPS III is a challenge for diagnosis, particularly in its early stages and in patients in which the course of the disease is attenuated. This is due to its variable course, non-specific early neuropsychiatric symptoms, and the absence of obvious somatic features compared to other types of MPS. After a definitive diagnosis has been made, interdisciplinary care must be provided for the patient and their family, and support given for the treatment of physical symptoms, ensuring the best possible care and quality of life for the patient and their family, as the condition is neurodegenerative.
Clinical trials of disease-modifying therapies (DMTs) for people with multiple sclerosis (pMS) are conducted in selected populations, excluding patients with comorbidities or concomitant medications. However, a large percentage of pMS have some additional disease, which could affect the response and choice of the DMT. The objective of this review is to assess how concurrent pathologies can impact the choice of DMTs. Relevant articles were selected through a systematic search in PubMed. Comorbidities were grouped for better classification into autoimmune, chronic infections, cardiovascular and metabolic, oncological and neuropsychiatric. In autoimmune pathologies, it is key to take into account the effects of TME on them and the possibility of interaction with their specific treatments. Immunomodulatory therapies are safe for people with chronic infections. Immunosuppressive treatments are generally contraindicated in people with active infections. In cardiovascular and metabolic comorbidities, infusion reactions associated with monoclonal antibodies, and the phenomena of starting treatment with S1P modulators, must be taken into account. DMTs with an immunosuppressive effect are contraindicated in people with active malignancies. Although psychiatric pathology per se does not preclude the use of DMTs, caution should be exercised when new psychiatric symptoms appear. For these reasons, among the multiple factors that must be considered when starting or changing a DMT in pMS, comorbidities constitute a decisive element.