Reviews & Analysis

Advances in neuroimaging research have enabled the development of predictive models that integrate information from multiple brain systems. Here, Perovnik, Rus and colleagues discuss the detection and validation of neurodegenerative disease-specific functional brain networks and consider their relationship to pathological processes and disease-related genotypes.

Technological advances over the past decade have made precision genetic diagnosis available to many patients. The findings of a new study demonstrate that genetic diagnosis in epilepsy can lead to changes in clinical management that manifest as positive outcomes for the patient. The results herald a new era in which precision diagnosis will lead to precision medicine.

Here, Spires-Jones and colleagues review our current understanding of the mechanisms underlying synaptic degeneration in Alzheimer disease and highlight key questions that still need to be answered. They also discuss novel therapeutic approaches that target the synapse.

Gene therapies show promise for treating epilepsy, but most strategies target cells across an entire brain region rather than selecting pathologically hyperexcited neurons. Researchers have now developed a conditional gene therapy strategy that downregulates firing activity only in neurons that are pathologically overactive and switches off when brain circuit activity has returned to baseline.

Amyotrophic lateral sclerosis (ALS) is a devastating, incurable disease characterized by progressive loss of upper and lower motor neurons. Here, the authors describe the current landscape of genetic therapies for ALS and discuss new opportunities for gene replacement therapy, focusing on loss-of-function mutations.

A new study provides evidence for an association between COVID-19 and long-term neurological syndromes. The findings highlight the need for further research into the long-term neurological consequences of SARS-CoV-2 infection and the development of strategies that lessen the effects of these consequences on patient quality of life and on healthcare systems.

Despite substantial research advances, treatment of neuropathic pain remains inadequate and responses to treatment are highly variable. In this Perspective, the authors argue that rational stratification of patients with neuropathic pain will aid identification of subgroups of patients who will benefit most from a given treatment.

In this Review, Savitz and Cox consider the evidence for a model of cell-based therapy referred to as the bioreactor hypothesis, in which exogenous cells migrate to peripheral organs and reprogramme host immune cells to generate an anti-inflammatory, regenerative environment.

In a study of 17,000 Medicare beneficiaries with mild cognitive impairment or dementia, non-Hispanic white older adults were more likely than Asian, Black or Hispanic older adults to have elevated cortical amyloid, as measured by PET. These findings have important implications for the use of amyloid-targeting therapies.

In this Review, the authors provide an overview of evidence that activity-regulated myelination is required for brain adaptation and learning, and discuss how dysregulation of activity-dependent myelination contributes to neurological disease and could be a new therapeutic target.

Here, the authors discuss the potential effects of social determinants of health on multiple sclerosis risk and outcomes. They suggest that addressing these determinants of health could substantially improve the lives of individuals with multiple sclerosis and call for more research.

Genome-wide association studies have identified loci associated with neurodegenerative disease risk, but many of the implicated genetic variants are noncoding and their functional roles remain unclear. Using massively parallel reporter assays, CRISPR-based validation and genomic annotations, a new study functionally characterizes regulatory risk variants associated with Alzheimer disease and progressive supranuclear palsy.

In this Perspective, the authors discuss the importance of performing well-designed observational studies on Alzheimer disease. They highlight novel approaches to enhance causal inference and discuss ways in which observational data can provide a bridge between preclinical findings and clinical trials.

In this Review, Vezzani et al. discuss how dysregulation of key astrocyte functions — gliotransmission, cell metabolism and immune function — contribute to the development and progression of hyperexcitability in epilepsy and consider strategies to mitigate astrocyte dysfunction.

Following successful clinical trials of a gene therapy for Leber hereditary optic neuropathy, Pitceathly and colleagues discuss progress towards genetic therapies for other primary mitochondrial diseases. They highlight advances in DNA editing technologies and offer their view on obstacles to clinical application.

In this Review, Eichmüller and Knoblich discuss how human brain organoids can recapitulate the unique processes that occur in human brain development and how they can complement classical approaches to revolutionize research into neurological diseases.

Most cases of Alzheimer disease (AD) have a complex aetiology, probably involving multiple genetic and environmental factors. In this Review, the authors discuss how various environmental AD risk factors could induce epigenetic modifications of key AD-associated genes and pathways.

In the first two phase II trials of therapies that target α-synuclein to treat Parkinson disease, the primary endpoints were not met. However, the limitations of these studies need to be addressed in future trials and alternative approaches to targeting α-synuclein should be pursued before α-synuclein is discounted as a target.

Currently, the anti-CD20 monoclonal antibody ocrelizumab is the only approved treatment for primary progressive multiple sclerosis (PPMS). However, a new study suggests that other immunomodulatory disease-modifying therapies that are often used to treat relapsing forms of multiple sclerosis could be effective in people with PPMS who have evidence of active inflammatory disease.

New work building on the results of genome-wide association studies in Alzheimer disease has identified molecular mechanisms that are shared with some psychiatric disorders. The study leveraged ‘omics data and has the realistic potential to elucidate unknown disease mechanisms; however, a lack of information about neuropsychiatric symptoms in the participants with Alzheimer disease limits the conclusions.