Modernization of a Large Spinal Cord Injuries and Disorders Registry: The Veterans Administration Experience

Since the 1990s, Veterans Health Administration (VHA) has maintained a registry of Veterans with Spinal Cord Injuries and Disorders (SCI/Ds) to guide clinical care, policy, and research. Historically, methods for collecting and recording data for the VHA SCI/D Registry (VSR) have required significant time, cost, and staffing to maintain, were susceptible to missing data, and caused delays in aggregation and reporting. Each subsequent data collection method was aimed at improving these issues over the last several decades. This paper describes the development and validation of a case-finding and data-capture algorithm that uses primary clinical data, including diagnoses and utilization across 9 million VHA electronic medical records, to create a comprehensive registry of living and deceased Veterans seen for SCI/D services since 2012. A multi-step process was used to develop and validate a computer algorithm to create a comprehensive registry of Veterans with SCI/D whose records are maintained in the enterprise wide VHA Corporate Data Warehouse. Chart reviews and validity checks were used to validate the accuracy of cases that were identified using the new algorithm. An initial cohort of 28,202 living and deceased Veterans with SCI/D who were enrolled in VHA care from 10/1/2012 through 9/30/2017 was validated. Tables, reports, and charts using VSR data were developed to provide operational tools to study, predict, and improve targeted management and care for Veterans with SCI/Ds. The modernized VSR includes data on diagnoses, qualifying fiscal year, recent utilization, demographics, injury, and impairment for 38,022 Veterans as of 11/2/2022. This establishes the VSR as one of the largest ongoing longitudinal SCI/D datasets in North America and provides operational reports for VHA population health management and evidence-based rehabilitation. The VSR also comprises one of the only registries for individuals with non-traumatic SCI/Ds and holds potential to advance research and treatment for multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), and other motor neuron disorders with spinal cord involvement. Selected trends in VSR data indicate possible differences in the future lifelong care needs of Veterans with SCI/Ds. Future collaborative research using the VSR offers opportunities to contribute to knowledge and improve health care for people living with SCI/Ds.

Natural compounds modulate the autophagy with potential implication of stroke

Stroke is considered a leading cause of mortality and neurological disability, which puts a huge burden on individuals and the community. To date, effective therapy for stroke has been limited by its complex pathological mechanisms. Autophagy refers to an intracellular degrading process with the involvement of lysosomes. Autophagy plays a critical role in maintaining the homeostasis and survival of cells by eliminating damaged or non-essential cellular constituents. Increasing evidence support that autophagy protects neuronal cells from ischemic injury. However, under certain circumstances, autophagy activation induces cell death and aggravates ischemic brain injury. Diverse naturally derived compounds have been found to modulate autophagy and exert neuroprotection against stroke. In the present work, we have reviewed recent advances in naturally derived compounds that regulate autophagy and discussed their potential application in stroke treatment.

Pneumomediastinum while using mechanical insufflation-exsufflation after recovery from riluzole-induced interstitial lung disease

We, herein, report a 61-year-old male patient with amyotrophic lateral sclerosis (ALS) complicated pneumomediastinum while using mechanical insufflation-exsufflation (MI-E) after recovery from riluzole (RZ)-induced interstitial lung disease (RZ-ILD). After the treatment of RZ-ILD, he required non-invasive mechanical ventilation (NIV) at minimal pressure settings and MI-E to manage ALS-related breathing and airway-clearance issues, respectively. After a while, he developed progressive worsening dyspnoea, and chest computed tomography revealed extensive pneumomediastinum that had spread to the area surrounding the oesophagus, the retrosternal space, and the pericardial space. He was treated with immediate discontinuation of MI-E; however, he had to keep using NIV to support his severe respiratory muscle involvement. Pneumomediastinum gradually reduced in size and no recurrence of pneumomediastinum occurred. The clinical course of our patient suggests that excessive coughing associated with MI-E combined with his previous RZ-ILD, which potentially renders his lungs vulnerable to airway pressure, may have been the aetiological factors for secondary pneumomediastinum, i.e. barotrauma. Clinicians should be aware of the risk of pneumomediastinum while using MI-E in patients with ALS, who have other pre-existing risk factors for pneumomediastinum, such as drug-induced ILD in our case.

Recent developments on PET radiotracers for TSPO and their applications in neuroimaging

The 18 kDa translocator protein (TSPO), previously known as the peripheral benzodiazepine receptor, is predominately localized to the outer mitochondrial membrane in steroidogenic cells. Brain TSPO expression is relatively low under physiological conditions, but is upregulated in response to glial cell activation. As the primary index of neuroinflammation, TSPO is implicated in the pathogenesis and progression of numerous neuropsychiatric disorders and neurodegenerative diseases, including Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), multiple sclerosis (MS), major depressive disorder (MDD) and obsessive compulsive disorder (OCD). In this context, numerous TSPO-targeted positron emission tomography (PET) tracers have been developed. Among them, several radioligands have advanced to clinical research studies. In this review, we will overview the recent development of TSPO PET tracers, focusing on the radioligand design, radioisotope labeling, pharmacokinetics, and PET imaging evaluation. Additionally, we will consider current limitations, as well as translational potential for future application of TSPO radiopharmaceuticals. This review aims to not only present the challenges in current TSPO PET imaging, but to also provide a new perspective on TSPO targeted PET tracer discovery efforts. Addressing these challenges will facilitate the translation of TSPO in clinical studies of neuroinflammation associated with central nervous system diseases.

Table olives and health: a review

Table olives, a product of olive tree (Olea europaea L.), is an important fermented product of the Mediterranean Diet. Agronomical factors, particularly the cultivar, the ripening stage and the processing method employed are the main factors influencing the nutritional and non-nutritional composition of table olives and their organoleptic properties. The important nutritional value of this product is due to its richness in monounsaturated fat (MUFA), mainly oleic acid, fibre and vitamin E together with the presence of several phytochemicals. Among these, hydroxytyrosol (HT) is the major phenolic compound present in all types of table olives. There is a scarcity of in vitro, in vivo and human studies of table olives. This review focused comprehensively on the nutrients and bioactive compound content as well as the health benefits assigned to table olives. The possible health benefits associated with their consumption are thought to be primarily related to effects of MUFA on cardiovascular health, the antioxidant (AO) capacity of vitamin E and its role in protecting the body from oxidative damage and the anti-inflammatory and AO activities of HT. The influence of multiple factors on composition of the end product and the potential innovation in the production of table olives through the reduction of its final salt content was also discussed.

SQSTM1L341V variant that is linked to sporadic ALS exhibits impaired association with MAP1LC3 in cultured cells

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are genetically, pathologically and clinically-related progressive neurodegenerative diseases. Thus far, several SQSTM1 variations have been identified in patients with ALS and FTD. However, it remains unclear how SQSTM1 variations lead to neurodegeneration. To address this issue, we investigated the effects of ectopic expression of SQSTM1 variants, which were originally identified in Japanese and Chinese sporadic ALS patients, on the cellular viability, their intracellular distributions and the autophagic activity in cultured cells. Expression of SQSTM1 variants in PC12 cells exerted no observable effects on viabilities under both normal and oxidative-stressed conditions. Further, although expression of SQSTM1 variants in PC12 cells and Sqstm1-deficient mouse embryonic fibroblasts resulted in the formation of numerous granular SQSTM1-positive structures, called SQSTM1-bodies, their intracellular distributions were indistinguishable from those of wild-type SQSTM1. Nonetheless, quantitative colocalization analysis of SQSTM1-bodies with MAP1LC3 demonstrated that among ALS-linked SQSTM1 variants, L341V variant showed the significantly lower level of colocalization. However, there were no consistent effects on the autophagic activities among the variants examined. These results suggest that although some ALS-linked SQSTM1 variations have a discernible effect on the intracellular distribution of SQSTM1-bodies, the impacts of other variations on the cellular homeostasis are rather limited at least under transiently-expressed conditions.

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Ectopic expression of ALS-linked SQSTM1 variants does not affect cell viability.

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Ectopic expression of SQSTM1 in cells results in formation of SQSTM1-body.

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Ectopic expression of SQSTM1 in cells has marginal impacts on the autophagic activity.

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SQSTM1^L341V variant exhibits impaired association with LC3 in cultured cells.

Edaravone protects rat astrocytes from oxidative or neurotoxic inflammatory insults by restoring Akt/Bcl-2/Caspase-3 signaling axis

Astrocytes are the major glia cells in the central nervous system (CNS). Increasing evidence indicates that more than to be safe-guard and supporting cells for neurons, astrocytes play a broad spectrum of neuroprotective and pathological functions. Thus, they are compelling models to decipher mechanistic insights of glia cells to CNS insults and for the development of drugs. Edaravone is a free radical scavenger with the capacity to eliminate hydroxyl radicals and lipid peroxides. In this study, we examined the neuroprotective effects of edaravone in rat astrocytes challenged by hydrogen peroxide (H₂O₂) or bacterial lipopolysaccharides (LPS), respectively. We discovered that edaravone attenuated H₂O₂-induced oxidative stress by reactivating the Akt signaling axis and antagonistically restoring the expression of apoptosis associated regulators such as Bcl-2 and Caspase-3. Consistently, inhibition of Akt signaling by LY294002 attenuated the anti-oxidative activity of edaravone. In addition, edaravone mitigated LPS-induced morphological changes in astrocytes and alleviated the inflammatory activation and expression of TNF-α, IL-1β, IL-6 and NOS2. In summary, our data suggested that edavarone effectively protects astrocytes from oxidative stress or infectious insults, which may pave a new avenue for its application in preclinical research and human disease therapeutics.

Biomimetic carbon nanotubes for neurological disease therapeutics as inherent medication

Nowadays, nanotechnology is revolutionizing the approaches to different fields from manufacture to health. Carbon nanotubes (CNTs) as promising candidates in nanomedicine have great potentials in developing novel entities for central nervous system pathologies, due to their excellent physicochemical properties and ability to interface with neurons and neuronal circuits. However, most of the studies mainly focused on the drug delivery and bioimaging applications of CNTs, while neglect their application prospects as therapeutic drugs themselves. At present, the relevant reviews are not available yet. Herein we summarized the latest advances on the biomedical and therapeutic applications of CNTs in vitro and in vivo for neurological diseases treatments as inherent therapeutic drugs. The biological mechanisms of CNTs-mediated bio-medical effects and potential toxicity of CNTs were also intensely discussed. It is expected that CNTs will exploit further neurological applications on disease therapy in the near future.

Counter effects of Asiaticosids-D through putative neurotransmission on rotenone induced cerebral ganglionic injury in Lumbricus terrestris

Asiaticoside-D (AD) was shown to efficacy of ganglionic degenerated Lumbricus terrestris as a pioneering observation in our earlier research. Though, extract molecular mechanisms of AD for degenerative diseases (DDs) remains largely unknown. We investigated the neuroprotective effects of AD against ROT in cerebral ganglions (CGs) of degenerative L. terrestris. Worms were exposed to 0.4 ppm ROT for 7 days were subjected to co- treatment with 15 ppm of AD. After, CGs was removed. The levels oxidant, non-antioxidant, antioxidant status, ganglioside, ceramide and ceramide glycanase (CGase) were estimated. The m-RNA levels of dopamine transporter (DAT), octopamine transporter (OAT), innexins-9 (inx-9), ionotropic glutamate receptor 3 (iGlu3), heat shock proteins (hsp70), XPRLamide neuropeptide precursor, tyramine beta-hydroxylase (tbh-1) and β- adrenergic receptor kinase-2 (β-ARK2-3) by semi-qRT- PCR. The expression pattern of tyramine beta hydroxylase (TBH), glutamate receptor (iGluR), serotonin transporter (SERT), dopamine transporters (DAT), nerve growth factors (NGF), cytochrome C oxidase (COC), NADH dehydogenase subunit-1 (ND-1), neurotrophin receptor p75 (p75NTR), neuronal nitric oxiside synthase (nNOs) interleukin 1- beta (IL1-β) and tumor necrosis factor alpha (TNF-α) by western blotting. Glutaminergic, serotogenic and dopaminergic toxicity variations were also performed. The levels of oxidant, non-antioxidant, antioxidant status, lipids, proteins and m-RNAs were significantly altered (p < 0.001) on ROT-induced (group II) and their levels were significantly changes (p < 0.05) by ROT+AD in CGs. The sensitive study plan concluded the neuroprotective effects of AD against ROT induced degeneration in worms and suggest that the AD deserves future studies for its use as an effective alternative medicine that could minimize the morbidity of ganglionic degenerative diseases patients.

Long-term interleukin-33 treatment delays disease onset and alleviates astrocytic activation in a transgenic mouse model of amyotrophic lateral sclerosis

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Th2-type cytokine IL-33 delayed the disease onset of female SOD1-G93 A transgenic ALS mice.

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IL-33 decreased the proportion of T cells in the spleens and lymph nodes of female mice.

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IL-33 decreased astrocytic activation in the spinal cord of female mice.

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Male mice were unresponsive to the treatment.

Inflammation is a prominent feature of the neuropathology of amyotrophic lateral sclerosis (ALS). Emerging evidence suggests that inflammatory cascades contributing to the disease progression are not restricted to the central nervous system (CNS) but also occur peripherally. Indeed, alterations in T cell responses and their secreted cytokines have been detected in ALS patients and in animal models of ALS. One key cytokine responsible for the shift in T cell responses is interleukin-33 (IL-33), which stimulates innate type 2 immune cells to produce a large amount of Th2 cytokines that are possibly beneficial in the recovery processes of CNS injuries. Since the levels of IL-33 have been shown to be decreased in patients affected with ALS, we sought to determine whether a long-term recombinant IL-33 treatment of a transgenic mouse model of ALS expressing G93A-superoxide dismutase 1 (SOD1-G93A) alters the disease progression and ameliorates the ALS-like disease pathology. SOD1-G93A mice were treated with intraperitoneal injections of IL-33 and effects on disease onset and inflammatory status were determined. Spinal cord (SC) neurons, astrocytes and T-cells were exposed to IL-33 to evaluate the cell specific responses to IL-33. Treatment of SOD1-G93A mice with IL-33 delayed the disease onset in female mice, decreased the proportion of CD4+ and CD8 + T cell populations in the spleen and lymph nodes, and alleviated astrocytic activation in the ventral horn of the lumbar SC. Male SOD1-G93A mice were unresponsive to the treatment. In vitro studies showed that IL-33 is most likely not acting directly on neurons and astrocytes, but rather conveying its effects through peripheral T-cells. Our results suggest that strategies directed to the peripheral immune system may have therapeutic potential in ALS. The effect of gender dimorphisms to the treatment efficacy needs to be taken into consideration when designing new therapeutic strategies for CNS diseases.

Integrated imaging of [11C]-PBR28 PET, MR diffusion and magnetic resonance spectroscopy 1H-MRS in amyotrophic lateral sclerosis

Objective

To determine the relationship between brain tissue metabolites measured by in vivo magnetic resonance spectroscopy (¹H-MRS), and glial activation assessed with [¹¹C]-PBR28 uptake in people with amyotrophic lateral sclerosis (ALS).

Methods

Forty ALS participants were evaluated clinically using the revised ALS functional rating scale (ALSFRS-R) and upper motor neuron burden (UMNB). All participants underwent simultaneous brain [¹¹C]-PBR28 PET and MR imaging including diffusion tensor imaging to acquire fractional anisotropy (FA). [¹¹C]-PBR28 uptake was measured as standardized uptake values normalized by whole brain mean (SUVR). ¹H-MRS metabolite ratios (myo-inositol/creatine, mI/Cr; N-acetylaspartate/creatine, NAA/Cr) were measured within the precentral gyri and brain stem (regions known to be involved in ALS pathophysiology), and precuneus (which served as a control region). Whole brain voxel-wise correlation analyses were employed to identify brain regions exhibiting an association between metabolites within the VOIs and [¹¹C]-PBR28 uptake.

Results

In the precentral gyri, [¹¹C]-PBR28 uptake correlated positively with mI/Cr and negatively with NAA/Cr. The same correlations were not statistically significant in the brain stem, or in the control precuneus region. Whole brain voxel-wise correlation analyses between the estimated brain metabolites within the VOIs and SUVR were highly correlated in the precentral gyri. Decreased FA values in the precentral gyri were correlated with reduced NAA/Cr and elevated mI/Cr. Higher UMNB was correlated with increased [¹¹C]-PBR28 uptake and mI/Cr, and decreased NAA/Cr. ALSFRS-R total score correlated positively with NAA/Cr and negatively with mI/Cr.

Conclusion

Integrated PET-MR and ¹H-MRS imaging demonstrates associations between markers for neuronal integrity and neuroinflammation and may provide valuable insights into disease mechanisms in ALS.

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This study evaluates the relationship between ¹H-MRS and [¹¹C]-PBR28 PET-MR measures in people with ALS.

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Myo-inositol/Creatine correlates positively with glial activation measured by [¹¹C]-PBR28 PET, and negatively with fractional anisotropy.

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N-acetyl-aspartate/Creatine correlates negatively with [¹¹C]-PBR28 PET, and positively with fractional anisotropy.

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Myo-inositol/Creatine and N-acetyl-aspartate/Creatine correlate with ALS-functional rating scale and upper motor neuron burden.

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¹H-MRS and PET-MR measures provide complementary information to better understand brain pathology in people with ALS.

SPG11 mutations cause widespread white matter and basal ganglia abnormalities, but restricted cortical damage

SPG11 mutations are the major cause of autosomal recessive Hereditary Spastic Paraplegia. The disease has a wide phenotypic variability indicating many regions of the nervous system besides the corticospinal tract are affected. Despite this, anatomical and phenotypic characterization is restricted. In the present study, we investigate the anatomical abnormalities related to SPG11 mutations and how they relate to clinical and cognitive measures. Moreover, we aim to depict how the disease course influences the regions affected, unraveling different susceptibility of specific neuronal populations. We performed clinical and paraclinical studies encompassing neuropsychological, neuroimaging, and neurophysiological tools in a cohort of twenty-five patients and age matched controls. We assessed cortical thickness (FreeSurfer software), deep grey matter volumes (T1-MultiAtlas tool), white matter microstructural damage (DTI-MultiAtlas) and spinal cord morphometry (Spineseg software) on a 3 T MRI scan. Mean age and disease duration were 29 and 13.2 years respectively. Sixty-four percent of the patients were wheelchair bound while 84% were demented. We were able to unfold a diffuse pattern of white matter integrity loss as well as basal ganglia and spinal cord atrophy. Such findings contrasted with a restricted pattern of cortical thinning (motor, limbic and parietal cortices). Electromyography revealed motor neuronopathy affecting 96% of the probands. Correlations with disease duration pointed towards a progressive degeneration of multiple grey matter structures and spinal cord, but not of the white matter. SPG11-related hereditary spastic paraplegia is characterized by selective neuronal vulnerability, in which a precocious and widespread white matter involvement is later followed by a restricted but clearly progressive grey matter degeneration.

Cortical markers of cognitive syndromes in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) can be associated with a spectrum of cognitive and behavioural symptoms, but the related patterns of focal cortical atrophy in non-demented ALS patients remain largely unknown. We enrolled 48 non-demented ALS patients and 26 healthy controls for a comprehensive neuropsychological assessment and a magnetic resonance exam. Behavioural and cognitive impairment was defined on the basis of a data-driven multi-domain approach in 21 ALS patients. Averaged cortical thickness of 74 bilateral brain regions was used as a measure of cortical atrophy. Cortical thinning in a fronto-parietal network, suggesting a disease-specific pattern of neurodegeneration, was present in all patients, independent of cognitive and behavioural status. Between-group and correlational analyses revealed that inferior frontal, temporal, cingular and insular thinning are markers for cognitive and behavioural deficits, with language impairment mainly related to left temporal pole and insular involvement. These specific correlates support the concept of a spectrum of deficits, with an overlap between the ALS cognitive phenotypes and the syndromes of frontotemporal dementia.

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Language, social cognition and executive dysfunctions are frequent symptoms in ALS.

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Fronto-parietal cortical thinning is present in non-demented ALS patients.

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Temporal, cingular and insular thinning are markers for cognitive impairment in ALS.

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Left temporal pole and insular thinning is linked to language impairment in ALS.

Long-term effects of edaravone on survival of patients with amyotrophic lateral sclerosis

Background and purpose

Oxidative stress has been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). Edaravone, a free radical scavenger, was approved as a therapeutic drug for ALS in 2015 in Japan. A phase 3 clinical trial demonstrated a smaller decline in ALS functional scale scores compared with placebo. However, the long-term effects of edaravone on ALS patients remain unclear. This study aimed to retrospectively investigate the long-term effects of edaravone on the survival of ALS patients.

Methods

We retrospectively analyzed 27 consecutive patients with ALS who were treated with edaravone and 30 consecutive ALS patients who were not treated with edaravone between 2010 and 2016.

Results

The differences of ALSFRS-R scores from baseline to 6 months was significantly reduced in the edaravone group, compared to the control group. The changes in serum creatinine, as a possible marker of ALS severity, from baseline to 6 and 12 months were significantly improved in the edaravone group, compared to the control group. The survival rate was significantly improved in the edaravone group compared with control patients.

Conclusion

Our retrospective single-center analysis suggests slower progression and better prognosis of ALS patients with edaravone treatment. Further investigation, including prospective multicenter analysis, is warranted to confirm the usefulness of edaravone for a better prognosis of ALS.

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We retrospectively investigate the effects of edaravone on ALS patients.

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The differences of ALSFRS-R scores were reduced in the edaravone group.

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The changes in serum creatinine were improved in the edaravone group.

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The survival rate was improved in the edaravone group.

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A prospective multicenter analysis is warranted to confirm usefulness of edaravone.

Influence of placement sites of the active recording electrode on CMAP configuration in the trapezius muscle

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The active recording electrode site influences the CMAP waveform of the trapezius muscle (TM).

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CMAP becomes high by placement of the active recording electrode 2 cm behind the belly of the TM.

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Volume conduction from the supraspinatus muscle affects the CMAP waveform of the TM.

Objective

We investigated how the active electrode placement site influences compound muscle action potential (CMAP) configuration of the upper trapezius muscle (TM).

Methods

A nerve conduction study of the accessory nerve was performed, and the CMAPs obtained with two different placement sites, i.e., placement of the active recording electrode on the belly of the upper TM (CMAP-A) and placement of the electrode 2 cm behind the belly (CMAP-B), were compared. CMAPs were also obtained with the active recording electrode placed in the supraspinous fossa (CMAP-C).

Results

All CMAPs were recorded from 21 healthy volunteers. The mean peak-to-peak amplitude of CMAP-B was 3.4 mV higher than that of CMAP-A (11.0 ± 4.0 mV vs. 14.4 ± 4.9 mV; P < 0.01). The mean peak-to-peak amplitude of CMAP-C was 10.3 ± 5.0 mV.

Conclusions

CMAP of the upper TM was always higher when the active recording electrode was placed 2 cm behind the belly of the muscle.

Significance

When stimulating the accessory nerve, a current spread occurs to the C5 spinal nerve root and another CMAP originating from the supraspinatus muscle occurs in the supraspinous fossa. The volume conduction from the supraspinatus muscle affects the active recording electrode on the TM, resulting in an increase in CMAP amplitude.

Network degeneration and dysfunction in presymptomatic C9ORF72 expansion carriers

Hexanucleotide repeat expansions in C9ORF72 are the most common known genetic cause of familial and sporadic frontotemporal dementia and amyotrophic lateral sclerosis. Previous work has shown that patients with behavioral variant frontotemporal dementia due to C9ORF72 show salience and sensorimotor network disruptions comparable to those seen in sporadic behavioral variant frontotemporal dementia, but it remains unknown how early in the lifespan these and other changes in brain structure and function arise. To gain insights into this question, we compared 15 presymptomatic carriers (age 43.7 ± 10.2 years, nine females) to matched healthy controls. We used voxel-based morphometry to assess gray matter, diffusion tensor imaging to interrogate white matter tracts, and task-free functional MRI to probe the salience, sensorimotor, default mode, and medial pulvinar thalamus-seeded networks. We further used a retrospective chart review to ascertain psychiatric histories in carriers and their non-carrier family members. Carriers showed normal cognition and behavior despite gray matter volume and brain connectivity deficits that were apparent as early as the fourth decade of life. Gray matter volume deficits were topographically similar though less severe than those in patients with behavioral variant frontotemporal dementia due to C9ORF72, with major foci in cingulate, insula, thalamus, and striatum. Reduced white matter integrity was found in the corpus callosum, cingulum bundles, corticospinal tracts, uncinate fasciculi and inferior longitudinal fasciculi. Intrinsic connectivity deficits were detected in all four networks but most prominent in salience and medial pulvinar thalamus-seeded networks. Carrier and control groups showed comparable relationships between imaging metrics and age, suggesting that deficits emerge during early adulthood. Carriers and non-carrier family members had comparable lifetime histories of psychiatric symptoms. Taken together, the findings suggest that presymptomatic C9ORF72 expansion carriers exhibit functionally compensated brain volume and connectivity deficits that are similar, though less severe, to those reported during the symptomatic phase. The early adulthood emergence of these deficits suggests that they represent aberrant network patterning during development, an early neurodegeneration prodrome, or both.

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Presymptomatic C9ORF72 expansion carriers have brain connectivity deficits.

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These deficits may be a developmental lesion rather than early neurodegeneration.

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Non-carriers and presymptomatic carriers share psychiatric symptomatology.

Longitudinal imaging in C9orf72 mutation carriers: Relationship to phenotype

Expansion mutations in the C9orf72 gene may cause amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), or mixtures of the two clinical phenotypes. Different imaging findings have been described for C9orf72-associated diseases in comparison with sporadic patients with the same phenotypes, but it is uncertain whether different phenotypes have a common genotype-associated imaging signature. To address this question, 27 unrelated C9orf72 expansion mutation carriers (C9 +) with varied phenotypes, 28 age-matched healthy controls and 22 patients with sporadic ALS (sALS) underwent 3T MRI scanning and clinical phenotyping. Measures of brain volumes and cortical thickness were extracted from T1 images. Compared to healthy controls and sALS patients, symptomatic C9 + subjects had greater ventricular volume loss and thalamic atrophy for age, with diffuse, patchy cortical thinning. Asymptomatic carriers did not differ from controls. C9 + ALS and ALS-FTD patients had less thinning of the motor cortex than sALS patients, but more thinning in extramotor regions, particularly in frontal and temporal lobes. C9 + ALS patients differed from sporadic ALS patients in the thickness of the superior frontal gyrus and lateral orbitofrontal cortex. Thickness of the precentral gyrus was weakly correlated with the revised ALS functional rating scale. Thickness of many cortical regions, including several frontal and temporal regions, was moderately correlated with letter fluency scores. Letter fluency scores were weakly correlated with ventricular and thalamic volume. To better understand how imaging findings are related to disease progression, nineteen C9 + subjects and 23 healthy controls were scanned approximately 6 months later. Ventricular volume increased in C9 + patients with FTD and ALS-FTD phenotypes and remained stable in asymptomatic C9 + subjects. We conclude that diffuse atrophy is a common underlying feature of disease associated with C9orf72 mutations across its clinical phenotypes. Ventricular enlargement can be measured over a 6-month time frame, and appears to be faster in patients with cognitive impairment.

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Patchy cortical thinning and diffuse atrophy are a hallmark of symptomatic ALS and FTD C9orf72 mutation carriers.

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Symptomatic C9orf72 carriers have more atrophy and diffuse thinning than sporadic ALS patients and healthy controls.

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Ventricular enlargement can be detected over a 6-month interval in symptomatic C9orf72 carriers.

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Impaired letter fluency is associated with diffuse cortical thinning.

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Changes in letter fluency, but not ALSFRS-R are correlated with 6-month ventricular enlargement.

Funding Research Through the Online Partnership to Accelerate Research (OnPAR)

OnPAR-the Online Partnership to Accelerate Research-seeks to provide a second opportunity for funding of high-quality, unfunded applications originally submitted to the National Institutes of Health and other national and international funding agencies. OnPAR will match applicable, unfunded applications with the research priorities of nongovernment organizations such as private biomedical foundations, pharmaceutical companies, venture capital funds, and other private funds. Funding organization members will review and make final funding decisions through a simple, 2-step process whereby applicants can submit public abstracts directly to OnPAR. If a member requests additional information, then, by invitation only, an applicant can submit their original unfunded application and their peer review summary statement. Advancing research discovery and drug development to improve clinical outcomes for patients afflicted with or at risk for disease is the primary goal of OnPAR. OnPAR invites the scientific community to fully participate in this new funding paradigm by submitting their National Institutes of Health public abstracts so that funding members can review and potentially support these high-quality, unfunded applications.

Interhemispheric connectivity in amyotrophic lateral sclerosis: A near-infrared spectroscopy and diffusion tensor imaging study

PURPOSE

Aim of the present study was to investigate potential impairment of non-motor areas in amyotrophic lateral sclerosis (ALS) using near-infrared spectroscopy (NIRS) and diffusion tensor imaging (DTI). In particular, we evaluated whether homotopic resting-state functional connectivity (rs-FC) of non-motor associated cortical areas correlates with clinical parameters and disease-specific degeneration of the corpus callosum (CC) in ALS.

MATERIAL AND METHODS

Interhemispheric homotopic rs-FC was assessed in 31 patients and 30 healthy controls (HCs) for 8 cortical sites, from prefrontal to occipital cortex, using NIRS. DTI was performed in a subgroup of 21 patients. All patients were evaluated for cognitive dysfunction in the executive, memory, and visuospatial domains.

RESULTS

ALS patients displayed an altered spatial pattern of correlation between homotopic rs-FC values when compared to HCs (p = 0.000013). In patients without executive dysfunction a strong correlation existed between the rate of motor decline and homotopic rs-FC of the anterior temporal lobes (ATLs) (ρ = - 0.85, p = 0.0004). Furthermore, antero-temporal homotopic rs-FC correlated with fractional anisotropy in the central corpus callosum (CC), corticospinal tracts (CSTs), and forceps minor as determined by DTI (p < 0.05).

CONCLUSIONS

The present study further supports involvement of non-motor areas in ALS. Our results render homotopic rs-FC as assessed by NIRS a potential clinical marker for disease progression rate in ALS patients without executive dysfunction and a potential anatomical marker for ALS-specific degeneration of the CC and CSTs.

Mutations in the ubiquitin-binding domain of OPTN/optineurin interfere with autophagy-mediated degradation of misfolded proteins by a dominant-negative mechanism

OPTN (optineurin) is an autophagy receptor and mutations in the OPTN gene result in familial glaucoma (E50K) and amyotrophic lateral sclerosis (ALS) (E478G). However, the mechanisms through which mutant OPTN leads to human diseases remain to be characterized. Here, we demonstrated that OPTN colocalized with inclusion bodies (IBs) formed by mutant HTT/huntingtin protein (mHTT) in R6/2 transgenic mice and IBs formed by 81QNmHTT (nuclear form), 109QmHTT (cytoplasmic form) or the truncated form of TARDBP/TDP-43 (TARDBP(ND251)) in Neuro2A cells. This colocalization required the ubiquitin (Ub)-binding domain (UbBD, amino acids 424 to 511) of OPTN. Overexpression of wild-type (WT) OPTN decreased IBs through K63-linked polyubiquitin-mediated autophagy. E50K or 210 to 410Δ (with amino acids 210 to 410 deleted) whose mutation or deletion was outside the UbBD decreased the IBs formed by 109QmHTT or TARDBP(ND251), as was the case with WT OPTN. In contrast, UbBD mutants, including E478G, D474N, UbBDΔ, 411 to 520Δ and 210 to 520Δ, increased accumulation of IBs. UbBD mutants (E478G, UbBDΔ) retained a substantial ability to interact with WT OPTN, and were found to colocalize with polyubiquitinated IBs, which might occur indirectly through their WT partner in a WT-mutant complex. They decreased autophagic flux evidenced by alteration in LC3 level and turnover and in the number of LC3-positive puncta under stresses like starvation or formation of IBs. UbBD mutants exhibited a weakened interaction with MYO6 (myosin VI) and TOM1 (target of myb1 homolog [chicken]), important for autophagosome maturation, in cells or sorted 109QmHtt IBs. Taken together, our data indicated that UbBD mutants acted as dominant-negative traps through the formation of WT-mutant hybrid complexes to compromise the maturation of autophagosomes, which in turn interfered with OPTN-mediated autophagy and clearance of IBs.

Engineering enhanced protein disaggregases for neurodegenerative disease

Protein misfolding and aggregation underpin several fatal neurodegenerative diseases, including Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and frontotemporal dementia (FTD). There are no treatments that directly antagonize the protein-misfolding events that cause these disorders. Agents that reverse protein misfolding and restore proteins to native form and function could simultaneously eliminate any deleterious loss-of-function or toxic gain-of-function caused by misfolded conformers. Moreover, a disruptive technology of this nature would eliminate self-templating conformers that spread pathology and catalyze formation of toxic, soluble oligomers. Here, we highlight our efforts to engineer Hsp104, a protein disaggregase from yeast, to more effectively disaggregate misfolded proteins connected with PD, ALS, and FTD. Remarkably subtle modifications of Hsp104 primary sequence yielded large gains in protective activity against deleterious α-synuclein, TDP-43, FUS, and TAF15 misfolding. Unusually, in many cases loss of amino acid identity at select positions in Hsp104 rather than specific mutation conferred a robust therapeutic gain-of-function. Nevertheless, the misfolding and toxicity of EWSR1, an RNA-binding protein with a prion-like domain linked to ALS and FTD, could not be buffered by potentiated Hsp104 variants, indicating that further amelioration of disaggregase activity or sharpening of substrate specificity is warranted. We suggest that neuroprotection is achievable for diverse neurodegenerative conditions via surprisingly subtle structural modifications of existing chaperones.

The structural integrity of TDP-43 N-terminus is required for efficient aggregate entrapment and consequent loss of protein function

Nuclear factor TDP-43 has been shown to play a key role in Amyotrophic Lateral Sclerosis and Frontotemporal Dementia, where TDP-43 aggregates accumulate in patient's affected neurons and this event can cause neuronal dysfunction. A major focus of today's research is to discover the critical factors that lead to TDP-43 aggregation and the consequences for neuronal metabolism. From a structural point of view, several lines of evidence point toward TDP-43 C-terminus as a key domain able to mediate this process. Regarding this region, we have recently described a novel cellular TDP-43 aggregation model based on 12 tandem repetitions of its 339-366 Q/N rich prion-like domain. In addition, we have shown and confirmed that a minimal TDP-43 construct constituted by the N and C-terminal regions, but lacking both RRM domains, induce aggregation of endogenous TDP-43 and leads to its total loss of function as seen by changes in the alternative splicing of endogenous genes. In this work, we further characterize this model and show the importance of the N-terminus structure in the loss of function process. In addition, from a biochemical point of view we report that, as shown in a previous version of this model (GFP 12 × Q/N), the endogenous TDP-43 trapped in the aggregates undergoes the 2 most important post-translational modifications seen in pathological TDP-43 inclusions: ubiquitination and hyperphosphorylation.

Emerging role of RNA•DNA hybrids in C9orf72-linked neurodegeneration

RNA plays an active role in structural polymorphism of the genome through the formation of stable RNA•DNA hybrids (R-loops). R-loops can modulate normal physiological processes and are also associated with pathological conditions, such as those related to nucleotide repeat expansions. A guanine-rich hexanucleotide repeat expansion in chromosome 9 open reading frame 72 (C9orf72) has been linked to a spectrum of neurological conditions including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Here we discuss the possible roles, both locally and genome-wide, of R-loops that may arise from the C9orf72 hexanucleotide repeat. R-loops have the potential to influence the pathological processes identified in many repeat expansion diseases, such as repeat instability, transcriptional dysregulation, epigenetic modification, and antisense-mediated gene regulation. We propose that, given the wide-ranging consequences of R-loops in the cell, these structures could underlie multiple pathological processes in C9orf72-linked neurodegeneration.

Cysteine proteases as therapeutic targets: does selectivity matter? A systematic review of calpain and cathepsin inhibitors

Cysteine proteases continue to provide validated targets for treatment of human diseases. In neurodegenerative disorders, multiple cysteine proteases provide targets for enzyme inhibitors, notably caspases, calpains, and cathepsins. The reactive, active-site cysteine provides specificity for many inhibitor designs over other families of proteases, such as aspartate and serine; however, a) inhibitor strategies often use covalent enzyme modification, and b) obtaining selectivity within families of cysteine proteases and their isozymes is problematic. This review provides a general update on strategies for cysteine protease inhibitor design and a focus on cathepsin B and calpain 1 as drug targets for neurodegenerative disorders; the latter focus providing an interesting query for the contemporary assumptions that irreversible, covalent protein modification and low selectivity are anathema to therapeutic safety and efficacy.

Exposing asymmetric gray matter vulnerability in amyotrophic lateral sclerosis

Limb weakness in amyotrophic lateral sclerosis (ALS) is typically asymmetric. Previous studies have identified an effect of limb dominance on onset and spread of weakness, however relative atrophy of dominant and non-dominant brain regions has not been investigated. Our objective was to use voxel-based morphometry (VBM) to explore gray matter (GM) asymmetry in ALS, in the context of limb dominance. 30 ALS subjects were matched with 17 healthy controls. All subjects were right-handed. Each underwent a structural MRI sequence, from which GM segmentations were generated. Patterns of GM atrophy were assessed in ALS subjects with first weakness in a right-sided limb (n = 15) or left-sided limb (n = 15). Within each group, a voxelwise comparison was also performed between native and mirror GM images, to identify regions of hemispheric GM asymmetry. Subjects with ALS showed disproportionate atrophy of the dominant (left) motor cortex hand area, irrespective of the side of first limb weakness (p < 0.01). Asymmetric atrophy of the left somatosensory cortex and temporal gyri was only observed in ALS subjects with right-sided onset of limb weakness. Our VBM protocol, contrasting native and mirror images, was able to more sensitively detect asymmetric GM pathology in a small cohort, compared with standard methods. These findings indicate particular vulnerability of dominant upper limb representation in ALS, supporting previous clinical studies, and with implications for cortical organisation and selective vulnerability.

Increased in vivo glial activation in patients with amyotrophic lateral sclerosis: assessed with [(11)C]-PBR28

Evidence from human post mortem, in vivo and animal model studies implicates the neuroimmune system and activated microglia in the pathology of amyotrophic lateral sclerosis. The study aim was to further evaluate in vivo neuroinflammation in individuals with amyotrophic lateral sclerosis using [¹¹C]-PBR28 positron emission tomography. Ten patients with amyotrophic lateral sclerosis (seven males, three females, 38–68 years) and ten age- and [¹¹C]-PBR28 binding affinity-matched healthy volunteers (six males, four females, 33–65 years) completed a positron emission tomography scan. Standardized uptake values were calculated from 60 to 90 min post-injection and normalized to whole brain mean. Voxel-wise analysis showed increased binding in the motor cortices and corticospinal tracts in patients with amyotrophic lateral sclerosis compared to healthy controls (p_FWE < 0.05). Region of interest analysis revealed increased [¹¹C]-PBR28 binding in the precentral gyrus in patients (normalized standardized uptake value = 1.15) compared to controls (1.03, p < 0.05). In patients those values were positively correlated with upper motor neuron burden scores (r = 0.69, p < 0.05), and negatively correlated with the amyotrophic lateral sclerosis functional rating scale (r = –0.66, p < 0.05). Increased in vivo glial activation in motor cortices, that correlates with phenotype, complements previous histopathological reports. Further studies will determine the role of [¹¹C]-PBR28 as a marker of treatments that target neuroinflammation.

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We used PET to image in vivo glial activation in the brain of patients with ALS.

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Increased [¹¹C]PBR28 binding was observed in motor cortices in patients with ALS.

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Glial activation in the motor cortex correlated with ALS disease severity.

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Findings suggest clinical relevance of brain inflammation measured in vivo in ALS.

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[¹¹C]-PBR28 could be used as an in vivo marker of upper motor neuron injury in ALS.

Cerebro-cerebellar connectivity is increased in primary lateral sclerosis

Increased functional connectivity in resting state networks was found in several studies of patients with motor neuron disorders, although diffusion tensor imaging studies consistently show loss of white matter integrity. To understand the relationship between structural connectivity and functional connectivity, we examined the structural connections between regions with altered functional connectivity in patients with primary lateral sclerosis (PLS), a long-lived motor neuron disease. Connectivity matrices were constructed from resting state fMRI in 16 PLS patients to identify areas of differing connectivity between patients and healthy controls. Probabilistic fiber tracking was used to examine structural connections between regions of differing connectivity. PLS patients had 12 regions with increased functional connectivity compared to controls, with a predominance of cerebro-cerebellar connections. Increased functional connectivity was strongest between the cerebellum and cortical motor areas and between the cerebellum and frontal and temporal cortex. Fiber tracking detected no difference in connections between regions with increased functional connectivity. We conclude that functional connectivity changes are not strongly based in structural connectivity. Increased functional connectivity may be caused by common inputs, or by reduced selectivity of cortical activation, which could result from loss of intracortical inhibition when cortical afferents are intact.

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Functional connectivity is increased in primary lateral sclerosis.

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Functional connections with the cerebellum were prominent.

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Cortico-cerebellar connectivity correlated with clinical measures.

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No corresponding changes occurred in structural connectivity.

Systematic analysis of transcription-level effects of neurodegenerative diseases on human brain metabolism by a newly reconstructed brain-specific metabolic network

Network-oriented analysis is essential to identify those parts of a cell affected by a given perturbation. The effect of neurodegenerative perturbations in the form of diseases of brain metabolism was investigated by using a newly reconstructed brain-specific metabolic network. The developed stoichiometric model correctly represents healthy brain metabolism, and includes 630 metabolic reactions in and between astrocytes and neurons, which are controlled by 570 genes. The integration of transcriptome data of six neurodegenerative diseases (Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, multiple sclerosis, schizophrenia) with the model was performed to identify reporter features specific and common for these diseases, which revealed metabolites and pathways around which the most significant changes occur. The identified metabolites are potential biomarkers for the pathology of the related diseases. Our model indicated perturbations in oxidative stress, energy metabolism including TCA cycle and lipid metabolism as well as several amino acid related pathways, in agreement with the role of these pathways in the studied diseases. The computational prediction of transcription factors that commonly regulate the reporter metabolites was achieved through binding-site analysis. Literature support for the identified transcription factors such as USF1, SP1 and those from FOX families are known from the literature to have regulatory roles in the identified reporter metabolic pathways as well as in the neurodegenerative diseases. In essence, the reconstructed brain model enables the elucidation of effects of a perturbation on brain metabolism and the illumination of possible machineries in which a specific metabolite or pathway acts as a regulatory spot for cellular reorganization.

The ALS/FTLD-related RNA-binding proteins TDP-43 and FUS have common downstream RNA targets in cortical neurons

TDP-43 and FUS are linked to amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD), and loss of function of either protein contributes to these neurodegenerative conditions. To elucidate the TDP-43- and FUS-regulated pathophysiological RNA metabolism cascades, we assessed the differential gene expression and alternative splicing profiles related to regulation by either TDP-43 or FUS in primary cortical neurons. These profiles overlapped by >25% with respect to gene expression and >9% with respect to alternative splicing. The shared downstream RNA targets of TDP-43 and FUS may form a common pathway in the neurodegenerative processes of ALS/FTLD.

Structural imaging differences and longitudinal changes in primary lateral sclerosis and amyotrophic lateral sclerosis

Magnetic resonance imaging measures have been proposed as objective markers to study upper motor neuron loss in motor neuron disorders. Cross-sectional studies have identified imaging differences between groups of healthy controls and patients with amyotrophic lateral sclerosis (ALS) or primary lateral sclerosis (PLS) that correlate with disease severity, but it is not known whether imaging measures change as disease progresses. Additionally, whether imaging measures change in a similar fashion with disease progression in PLS and ALS is unclear. To address these questions, clinical and imaging evaluations were first carried out in a prospective cross-sectional study of 23 ALS and 22 PLS patients with similar motor impairment and 19 age-matched healthy controls. Clinical evaluations consisted of a neurological examination, the ALS Functional rating scale-revised, and measures of finger tapping, gait, and timed speech. Age and ALSFRS score were not different, but PLS patients had longer duration of symptoms. Imaging measures examined were cortical thickness, regional brain volumes, and diffusion tensor imaging of the corticospinal tract and callosum. Imaging measures that differed from controls in a cross-sectional vertex-wise analysis were used as regions of interest for longitudinal analysis, which was carried out in 9 of the ALS patients (interval 1.26 ± 0.72 years) and 12 PLS patients (interval 2.08 ± 0.93 years). In the cross-sectional study both groups had areas of cortical thinning, which was more extensive in motor regions in PLS patients. At follow-up, clinical measures declined more in ALS than PLS patients. Cortical thinning and grey matter volume loss of the precentral gyri progressed over the follow-up interval. Fractional anisotropy of the corticospinal tracts remained stable, but the cross-sectional area declined in ALS patients. Changes in clinical measures correlated with changes in precentral cortical thickness and grey matter volume. The rate of cortical thinning was greater in ALS patients with shorter disease durations, suggesting that thickness decreases in a non-linear fashion. Thus, cortical thickness changes are a potential imaging marker for disease progression in individual patients, but the magnitude of change likely depends on disease duration and progression rate. Differences between PLS and ALS patients in the magnitude of thinning in cross-sectional studies are likely to reflect longer disease duration. We conclude that there is an evolution of structural imaging changes with disease progression in motor neuron disorders. Some changes, such as diffusion properties of the corticospinal tract, occur early while cortical thinning and volume loss occur later.

The role of microglia in synaptic stripping and synaptic degeneration: a revised perspective

Chronic neurodegenerative diseases of the CNS (central nervous system) are characterized by the loss of neurons. There is, however, growing evidence to show that an early stage of this process involves degeneration of presynaptic terminals prior to the loss of the cell body. Synaptic plasticity in CNS pathology has been associated with microglia and the phenomenon of synaptic stripping. We review here the evidence for the involvement of microglia in synaptic stripping and synapse degeneration and we conclude that this is a case of guilt by association. In disease models of chronic neurodegeneration, there is no evidence that microglia play an active role in either synaptic stripping or synapse degeneration, but the degeneration of the synapse and the envelopment of a degenerating terminal appears to be a neuron autonomous event. We highlight here some of the gaps in our understanding of synapse degeneration in chronic neurodegenerative disease.