Volume 147, Issue 7, July 2024

This scientific commentary refers to ‘Connectome reorganization associated with temporal lobe pathology and its surgical resection’ by Larivière et al. (https://doi.org/10.1093/brain/awae141).

This scientific commentary refers to ‘Tiam1-mediated maladaptive plasticity underlying morphine tolerance and hyperalgesia’ by Yao et al. (https://doi.org/10.1093/brain/awae106).

Libet’s demonstration that activity in the supplementary motor area precedes conscious decision making is widely considered to have put the final nail in the coffin of dualism. Neurosurgeon Rickard Sjöberg argues that SMA resections show that Libet’s findings are in fact irrelevant to the neuroscientific discussion about free will.

Devine et al. argue that recent changes to clinical neurology training in the UK have the potential to exacerbate an existing crisis in academic neurology, and discuss what might be done to remedy the situation.

Clinicians and families face challenging decisions regarding the appropriateness of continuing or limiting life-sustaining therapies for patients with disorders of consciousness. Lissak and Young examine the ethical dimensions of these decisions, and the impact of cultural and religious perspectives on practice variation.

Frontotemporal dementia and amyotrophic lateral sclerosis share overlapping genetics and pathologies. Clayton et al. summarise recent evidence suggesting that presynaptic dysfunction is an early and common event in both diseases, and could represent a target for future disease-modifying therapies.

Okkels et al. review cholinergic changes in Lewy body disease, including Parkinson's disease, dementia with Lewy bodies, and isolated REM sleep behaviour disorder, and compare changes across different anatomical regions, patient groups, and disease stages.

APP gene dosage is strongly associated with Alzheimer’s disease pathogenesis. Hung et al. show that antisense oligonucleotides targeting APP can reduce APP protein levels and rescue impaired protein clearance in human cortical neurons with APP duplication, and can reduce both intracellular and extracellular Aβ-containing aggregates.

Maroofian et al. delineate a new form of autosomal recessive distal hereditary motor neuropathy (dHMN) with pyramidal features associated with RTN2 deficiency, and conclude that the disorder shares similarities with SIGMAR1-related dHMN and Silver-like syndromes.

Pavey et al. report that cortical hyperexcitability in ALS is mediated by dysfunction of distinct inhibitory and facilitatory cortical neuronal populations. Restoring function of the dysfunctional cortical neuronal populations may have therapeutic utility.

Carbayo et al. study the clinical and pathological features of a large series of patients with amyotrophic lateral sclerosis. They describe a high frequency of concurrent FTLD pathological features and highlight the marked heterogeneity within the disease and its main characteristics.

Kiianitsa, Lukes et al. show that multiple Alzheimer’s disease-associated TREM2 variants exert their pathogenic effects via altered TREM2 splicing. Understanding the mechanistic complexity of TREM2 dysfunction will improve risk assessment and guide therapeutic development.

By modelling neurons from the entorhinal cortex in silico, Rodriguez-Rodriguez et al. obtain evidence suggesting that the proto-oncogene DEK is likely to contribute to the vulnerability of these neurons to Alzheimer’s disease. Reducing DEK levels in these neurons in vitro leads to changes reminiscent of early Alzheimer’s disease pathology.

Using cross-sectional structural MRI, Baumeister et al. identify two distinct patterns of brain atrophy in a memory clinic-based sample of older adults. These atrophy patterns may be used to predict clinical and cognitive trajectories of patients, with potential implications for clinical practice and pharmacological trials.

Nilsson et al. explore potential synaptic CSF biomarkers of cognitive decline and find that certain proteins including SNAP-25 and 14-3-3 zeta/delta are elevated in Alzheimer’s disease, whereas neuronal pentraxins are reduced across dementias. The ratios of these proteins can be used to predict cognitive decline and brain atrophy.

Four-repeat tauopathies are rapidly progressive neurodegenerative diseases with mixed subcortical and cortical symptoms. Using advanced neuroimaging methods, Roemer et al. show that subcortical tau accumulation is associated with remote perfusion reductions indicative of neuronal dysfunction in functionally connected cortical regions.

Millar Vernetti et al. describe the clinical features of patients with pure autonomic failure that are associated with the highest risk of imminent phenoconversion to Parkinson’s disease, multiple system atrophy, and Lewy body dementia. Specific markers of autonomic, olfactory, cognitive, and motor function can help in predicting the final diagnosis.

Atkins et al. report that people with Huntington’s disease are less willing to exert cognitive effort than controls. However, they are similarly willing to exert physical effort, despite an impaired ability to do so. This suggests that cognitive and physical motivation are driven by separable domain-specific mechanisms.

Kaliuzhna et al. explore how the brains of patients with schizophrenia adapt to the range of available rewards and how this is related to symptoms of apathy. Adaptive coding is impaired in patients relative to control subjects, with the impairment being driven by a reduced ability to increase brain responses to smaller rewards in a narrow reward range.

Laugwitz et al. describe a novel syndromic neurodevelopmental disorder with characteristic malformations of the face and of the inner and outer ear. The autosomal recessive disorder is caused by biallelic loss-of-function variants in the ZSCAN10 gene.

Larivière et al. explore the consequences of focal brain lesions and their surgical resection on the organization of the human brain. They show that changes occur both at the lesion site and in distant regions, and explore how this reorganization relates to clinical variables at the individual patient level.

See Sainburg et al. (https://doi.org/10.1093/brain/awae172) for a scientific commentary on this article.

In a large collaborative study, Shi et al. show that spike ripples are more effective than other leading biomarkers at revealing brain areas that generate seizures. An automated spike ripple detector performed well in surgical patients across centres, providing a new tool to guide surgical care in patients with severe epilepsy.

Yao et al. identify Tiam1-mediated maladaptive plasticity in the spinal nociceptive network as an underlying cause of the development and maintenance of morphine tolerance and hyperalgesia. Inhibiting Tiam1 signalling reduced tolerance, suggesting potential to prolong morphine use in chronic pain management.

See Mangutov et al. (https://doi.org/10.1093/brain/awae170) for a scientific commentary on this article.

Reading and object naming both require interactions between the brain’s visual and language systems. Woolnough and Tandon use direct cortical stimulation, temporarily disrupting people’s ability to read or name, to map two distinct, selective brain regions essential for either reading or naming.

When hearing speech, ticker-tape synaesthetes automatically and vividly perceive the words in written form in their mind's eye. Using task-related and resting state functional MRI, Hauw et al. study 17 affected individuals and reveal the atypical functioning of their reading system, including regions also implicated in dyslexia.

Marsters et al. studied the frequency and outcomes of neurological disease associated with COVID-19 in over 355 000 people and determined that individuals with pre-existing neurological disorders were at greater risk of death. SARS-CoV-2 infection also increased the risk of new-onset neurological disorders post-infection that contribute to long COVID.

Kong et al. show in mice that upregulation of a protein called Prmt6 contributes to neuroinflammation and post-herpetic neuralgia following HSV-1 infection. Inhibiting Prmt6 reduces HSV-1-induced inflammation and improves innate immunity, suggesting that Prmt6 could be a potential therapeutic target.

Herranz et al. use TSPO-PET to image immune cell-mediated inflammation in the meninges and cortex of people with multiple sclerosis, and provide in vivo evidence implicating meningeal inflammation in the underlying disease pathogenesis.

Anti-IgLON5 disease is a rare subtype of autoimmune encephalitis with late onset. Yogeshwar et al. present genetic, clinical, and immune cell phenotyping data suggesting a stronger association with HLA-DQ over HLA-DR, and showing autoimmune reactivity against IgLON5 in a post-translationally modified form.