Background: Neurotropic B vitamins play crucial roles as coenzymes and beyond in the nervous system. Particularly vitamin B1 (thiamine), B6 (pyridoxine), and B12 (cobalamin) contribute essentially to the maintenance of a healthy nervous system. Their importance is highlighted by many neurological diseases related to deficiencies in one or more of these vitamins, but they can improve certain neurological conditions even without a (proven) deficiency.Aim: This review focuses on the most important biochemical mechanisms, how they are linked with neurological functions and what deficits arise from malfunctioning of these pathways.Discussion: We discussed the main role of B Vitamins on several functions in the peripheral and central nervous system (PNS and CNS) including cellular energetic processes, antioxidative and neuroprotective effects, and both myelin and neurotransmitter synthesis. We also provide an overview of possible biochemical synergies between thiamine, pyridoxine, and cobalamin and discuss by which major roles each of them may contribute to the synergy and how these functions are inter‐related and complement each other.Conclusion: Taking into account the current knowledge on the neurotropic vitamins B1, B6, and B12, we conclude that a biochemical synergy becomes apparent in many different pathways in the nervous system, particularly in the PNS as exemplified by their combined use in the treatment of peripheral neuropathy.

Despite having been referenced in the literature for over a decade, the term ‘mixed pain’ has never been formally defined. The strict binary classification of pain as being either purely neuropathic or nociceptive once left a good proportion of patients unclassified; even the recent adoption of ‘nociplastic pain’ in the IASP Terminology leaves out patients who present clinically with a substantial overlap of nociceptive and neuropathic symptoms. For these patients, the term ‘mixed pain’ is increasingly recognized and accepted by clinicians. Thus, an independent group of international multidisciplinary clinicians convened a series of informal discussions to consolidate knowledge and articulate all that is known (or, more accurately, thought to be known) and all that is not known about mixed pain. To inform the group’s discussions, a MEDLINE search for the Medical Subject Heading ‘mixed pain’ was performed via PubMed. The search strategy encompassed clinical trial articles and reviews from January 1990 to the present. Clinically relevant articles were selected and reviewed. This paper summarizes the group’s consensus on several key aspects of the mixed pain concept, envisioned to serve as a foundation for future attempts at generating a mechanistic and/or clinical definition of mixed pain. A definition would have important implications for the development of recommendations or guidelines for diagnosis and treatment of mixed pain.

Traumatic brain injury (TBI) is one of the leading causes of morbidity and mortality. Consequences vary from mild cognitive impairment to death and, no matter the severity of subsequent sequelae, it represents a high burden for affected patients and for the health care system. Brain trauma can cause neuronal death through mechanical forces that disrupt cell architecture, and other secondary consequences through mechanisms such as inflammation, oxidative stress, programmed cell death, and, most importantly, excitotoxicity. This review aims to provide a comprehensive understanding of the many classical and novel pathways implicated in tissue damage following TBI. We summarize the preclinical evidence of potential therapeutic interventions and describe the available clinical evaluation of novel drug targets such as vitamin B12 and ifenprodil, among others.

Self-medication (SM) is a global and growing phenomenon. It represents a public health problem due to antibiotic resistance, risk of adverse drug reactions, drug–drug interactions, disease masking, and increased morbidity. There is not a consensus on the definition of SM. The definitions found in different studies make it difficult to address this problem from a theoretical perspective and therefore find an adequate solution to this public health problem. The aim of this article is to search the medical literature to characterize the current understanding of SM in the medical community. We conducted a scoping review of definitions of SM by searching on PubMed – Medline, Embase, and LILACS using the following combination of keywords: ‘self-prescription’ or ‘self prescription’, ‘self-medication’ or ‘self medication’, or ‘automedication’ and ‘definition’ or ‘explanation’. The search was limited to articles containing the definition of SM, with no limit on language or year. Duplicate studies and those that did not mention the definition of SM were excluded from the final review. A total of 65 studies were included in the final selection. We found a vast heterogeneity in the definition of SM. Most articles based their definition of SM on the process of obtaining the drug, the nonparticipation of a specific health professional, the source of the medication, and the reason for SM. Other interesting concepts such as self-care, nonadherence to a prescription, reuse of stored drugs, and sharing and lending medicines were also considered forms of SM by other authors, however. This study highlights the need to reach a consensus regarding the definition of SM to adequately propose strategies to address this global health problem. This study shows the diverse concepts that need to be included in a future definition of SM. Plain Language Summary: Definition of self-medication: a review with systematic methodology Self-medication (SM) is a global and growing phenomenon that represents a public health problem due to antibiotic resistance, risk of dangerous side effects, interactions between drugs, and disease masking. Currently, there is not a consensus on the definition of SM, which makes it difficult to address this problem and therefore find an adequate solution. Making a standard definition would allow the development of programs focused on addressing drug-related problems associated with self-medication behavior. The purpose of this article is to search the medical literature to define the current understanding of SM in the medical community. We included a total of 65 studies and found a great variance in the definition of SM. Most articles based their definition of SM on the process of obtaining the drug, the nonparticipation of a specific health professional, the source of the medication, and the reason for SM. Other interesting concepts such as self-care, not following a prescription, reuse of stored drugs, and sharing and lending medicines were also considered forms of SM by other authors, however. Furthermore, this study highlights that SM is a wider concept that goes beyond aiming to promote and restore health, as aesthetic and recreational purposes are also reasons for SM that can put individuals at risk and compromise the correct and safe use of medications.

Alzheimer’s disease (AD) is a chronic neurodegenerative disease and the most frequent cause of progressive dementia in senior adults. It is characterized by memory loss and cognitive impairment secondary to cholinergic dysfunction and N-methyl-D-aspartate (NMDA)-mediated neurotoxicity. Intracellular neurofibrillary tangles, extracellular plaques composed of amyloid-β (Aβ), and selective neurodegeneration are the anatomopathological hallmarks of this disease. The dysregulation of calcium may be present in all the stages of AD, and it is associated with other pathophysiological mechanisms, such as mitochondrial failure, oxidative stress, and chronic neuroinflammation. Although the cytosolic calcium alterations in AD are not completely elucidated, some calcium-permeable channels, transporters, pumps, and receptors have been shown to be involved at the neuronal and glial levels. In particular, the relationship between glutamatergic NMDA receptor (NMDAR) activity and amyloidosis has been widely documented. Other pathophysiological mechanisms involved in calcium dyshomeostasis include the activation of L-type voltage-dependent calcium channels, transient receptor potential channels, and ryanodine receptors, among many others. This review aims to update the calcium-dysregulation mechanisms in AD and discuss targets and molecules with therapeutic potential based on their modulation.

Alzheimer’s disease (AD) is the most common type of dementia, mainly encompassing cognitive decline in subjects aged ≥65 years. Further, AD is characterized by selective synaptic and neuronal degeneration, vascular dysfunction, and two histopathological features: extracellular amyloid plaques composed of amyloid beta peptide (Aβ) and neurofibrillary tangles formed by hyperphosphorylated tau protein. Dementia and AD are chronic neurodegenerative conditions with a complex physiopathology involving both genetic and environmental factors. Recent clinical studies have shown that proton pump inhibitors (PPIs) are associated with risk of dementia, including AD. However, a recent case-control study reported decreased risk of dementia. PPIs are a widely indicated class of drugs for gastric acid-related disorders, although most older adult users are not treated for the correct indication. Although neurological side effects secondary to PPIs are rare, several preclinical reports indicate that PPIs might increase Aβ levels, interact with tau protein, and affect the neuronal microenvironment through several mechanisms. Considering the controversy between PPI use and dementia risk, as well as both cognitive and neuroprotective effects, the aim of this review is to examine the relationship between PPI use and brain effects from a neurobiological and clinical perspective.