Cortical thickness in ALS: towards a marker for upper motor neuron involvement.

OBJECTIVE: Examine whether cortical thinning is a disease-specific phenomenon across the spectrum of motor neuron diseases in relation to upper motor neuron (UMN) involvement. METHODS: 153 patients (112 amyotrophic lateral sclerosis (ALS), 19 patients with a clinical UMN phenotype, 22 with a lower motor neuron (LMN) phenotype), 60 healthy controls and 43 patients with an ALS mimic disorder were included for a cross-sectional cortical thickness analysis. Thirty-nine patients with ALS underwent a follow-up scan. T1-weighted images of the brain were acquired using a 3 T scanner. The relation between cortical thickness and clinical measures, and the longitudinal changes were examined. RESULTS: Cortical thickness of the precentral gyrus (PCG) was significantly reduced in ALS (p=1.71×10(-13)) but not in mimic disorders (p=0.37) or patients with an LMN phenotype (p=0.37), as compared to the group of healthy controls. Compared to patients with ALS, patients with a UMN phenotype showed an even lower PCG cortical thickness (p=1.97×10(-3)). Bulbar scores and arm functional scores showed a significant association with cortical thickness of corresponding body regions of the motor homunculus. Longitudinal analysis revealed a decrease of cortical thickness in the left temporal lobe of patients with ALS (parahippocampal region p=0.007 and fusiform cortex p=0.001). CONCLUSIONS: PCG cortical thinning was found to be specific for motor neuron disease with clinical UMN involvement. Normal levels of cortical thickness in mimic disorders or LMN phenotypes suggest that cortical thinning reflects pathological changes related to UMN involvement. Progressive cortical thinning in the temporal lobe suggests recruitment of non-motor areas, over time.

What does imaging reveal about the pathology of amyotrophic lateral sclerosis?

Amyotrophic lateral sclerosis (ALS) is now recognised to be a heterogeneous neurodegenerative syndrome of the motor system and its frontotemporal cortical connections. The development and application of structural and functional imaging over the last three decades, in particular magnetic resonance imaging (MRI), has allowed traditional post mortem histopathological and emerging molecular findings in ALS to be placed in a clinical context. Cerebral grey and white matter structural MRI changes are increasingly being understood in terms of brain connectivity, providing insights into the advancing degenerative process and producing candidate biomarkers. Such markers may refine the prognostic stratification of patients and the diagnostic pathway, as well as providing an objective assessment of changes in disease activity in response to future therapeutic agents. Studies are being extended to the spinal cord, and the application of neuroimaging to unaffected carriers of highly penetrant genetic mutations linked to the development of ALS offers a unique window to the pre-symptomatic landscape.

Structural brain network imaging shows expanding disconnection of the motor system in amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease, which primarily targets the motor system. The structural integrity of the motor network and the way it is embedded in the overall brain network is essential for motor functioning. We studied the longitudinal effects of ALS on the brain network using diffusion tensor imaging and questioned whether over time an increasing number of connections become involved or whether there is progressive impairment of a limited number of connections. The brain network was reconstructed based on "whole brain" diffusion tensor imaging data. We examined: (1) network integrity in 24 patients with ALS at baseline (T = 1) and at a more advanced stage of the disease (T = 2; interval 5.5 months) compared with a group of healthy controls and (2) progressive brain network impairment comparing patients at two time-points in a paired-analysis. These analyses demonstrated an expanding subnetwork of affected brain connections over time with a central role for the primary motor regions (P-values T = 1 0.003; T = 2 0.001). Loss of structural connectivity mainly propagated to frontal and parietal brain regions at T = 2 compared with T = 1. No progressive impairment of the initially affected (motor) connections could be detected. The main finding of this study is an increasing loss of network structure in patients with ALS. In contrast to the theory of ALS solely affecting a fixed set of primary motor connections, our findings show that the network of impaired connectivity is expanding over time. These results are in support of disease spread along structural brain connections.

Correlation between structural and functional connectivity impairment in amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease, characterized by progressive loss of motor function. While the pathogenesis of ALS remains largely unknown, imaging studies of the brain should lead to more insight into structural and functional disease effects on the brain network, which may provide valuable information on the underlying disease process. This study investigates the correlation between changes in structural connectivity (SC) and functional connectivity (FC) of the brain network in ALS. Structural reconstructions of the brain network, derived from diffusion weighted imaging (DWI), were obtained from 64 patients and 27 healthy controls. Functional interactions between brain regions were derived from resting-state fMRI. Our results show that (i) the most structurally affected connections considerably overlap with the most functionally impaired connections, (ii) direct connections of the motor cortex are both structurally and functionally more affected than connections at greater topological distance from the motor cortex, and (iii) there is a strong positive correlation between changes in SC and FC averaged per brain region (r = 0.44, P < 0.0001). Our findings indicate that structural and functional network degeneration in ALS is coupled, suggesting the pathogenic process affects both SC and FC of the brain, with the most prominent effects in SC.

Outpatient Check-In Using an Online Portal.

Background: Despite ongoing digital and technological developments, incorporation of new developments in outpatient care tends to be slow. Regarding an increasing demand for outpatient care, digitalization of health care carries the potential of a much needed more efficient and patient-oriented system. Objective: To optimize classic face-to-face outpatient clinic follow-up consultations and evaluate the added value of an upfront digital consult preparation (DCP). Methods: A cross-sectional observational study was conducted at Rijnstate Hospital (Arnhem, the Netherlands) among all consecutive patients, 18 years or older, who visited the Cardiology (in June 2021) or Neurology (in September 2021) outpatient clinic. All received a DCP survey before their scheduled outpatient clinic appointment, containing three questions regarding their upcoming visit. In addition, the involved health care providers were approached by using a questionnaire to share their experience regarding the DCP. Data concerning the experience of patients and health care providers was anonymous and gathered using Qualtrics.com. Results: All 25 involved health care providers (12 cardiologists, 13 neurologists) provided feedback. According to the health care providers DCP decreased the workload and improved theirs and patients' preparation. In total, 785 of 1626 (48.3%) patients filled-in the DCP before their appointment within a predetermined period. Only 4% of the patients wanted to change or cancel the consultation. A total of 122 of the 300 (40.1%) patients approached, filled-in a questionnaire to reflect on the DCP. Patients experienced DCP as an improvement of consultation, more time-efficient, increasing patients' and health care providers' preparation, increasing a feeling of acknowledgement and improving co-decision on type of consultation. The DCP did not attribute to co-deciding on treatment. Conclusion: DCP was perceived as an improvement of the standard outpatient care by both health care providers and patients with automated integration into the electronic patient record being of key importance.

Structural MRI reveals cortical thinning in amyotrophic lateral sclerosis.

OBJECTIVES: Amyotrophic lateral sclerosis (ALS) is a fatal disease characterised by combined upper and lower motor neuron degeneration. An early and accurate diagnosis is important for patient care and might facilitate the search for a more effective therapy. MRI was used to study the whole cortical mantle, applying an unbiased surface based approach to identify a marker of upper motor neuron involvement in ALS. METHODS: Surface based cortical morphology analyses were performed on structural, 3T MRI data of 45 patients with ALS and 25 matched healthy controls in a case control study design. These analyses consisted of measuring cortical thickness, surface area and volume. The effects of disease progression were examined by correlating cortical measures with progression rate and by longitudinal measures in 20 patients. RESULTS: Cortical morphology analyses revealed specific thinning in the precentral gyrus, considered the primary motor cortex, in patients with ALS compared with controls (p=6.3×10(-8)). Surface area was reduced in the right inferior parietal region (p=0.049) and volume--the product of cortical thickness and surface area--was reduced in the right precentral gyrus (p=0.031). From these findings, it appears that cortical thickness is superior in detecting the degenerative effects of ALS. Relative cortical thinning in temporal regions was related to faster clinical progression (right inferior temporal gyrus: p=3.3×10(-4)). CONCLUSIONS: Cortical thinning of the primary motor cortex might be a diagnostic marker for upper motor neuron degeneration in ALS. Relative thinning in temporal regions was associated with a rapidly progressive disease course.

Lithium lacks effect on survival in amyotrophic lateral sclerosis: a phase IIb randomised sequential trial.

OBJECTIVES: To determine the safety and efficacy of lithium for the treatment of amyotrophic lateral sclerosis (ALS) in a randomised, placebo controlled, double blind, sequential trial. METHODS: Between November 2008 and June 2011, 133 patients were randomised to receive lithium carbonate (target blood level 0.4-0.8 mEq/l) or placebo as add-on treatment with riluzole. The primary endpoint was survival, defined as death, tracheostomal ventilation or non-invasive ventilation for more than 16 h/day. Secondary outcome measures consisted of the revised ALS Functional Rating Scale and forced vital capacity. Analysis was by intention to treat and according to a sequential trial design. RESULTS: 61 patients reached a primary endpoint, 33 of 66 in the lithium group and 28 of 67 patients in the placebo group. Lithium did not significantly affect survival (cumulative survival probability of 0.73 in the lithium group (95% CI 0.63 to 0.86) vs 0.75 in the placebo group (95% CI 0.65 to 0.87) at 12 months and 0.62 in the lithium group (95% CI 0.50 to 0.76) vs 0.67 in the placebo group (95% CI 0.56 to 0.81) at 16 months). Secondary outcome measures did not differ between treatment groups. No major safety concerns were encountered. CONCLUSIONS: This trial, designed to detect a modest effect of lithium, did not demonstrate any beneficial effect on either survival or functional decline in patients with ALS. TRIAL REGISTRATION NUMBER: NTR1448. Name of trial registry: Lithium trial in ALS.

TDP-43 plasma levels are higher in amyotrophic lateral sclerosis.

Our objective was to investigate TDP-43 plasma levels in patients with amyotrophic lateral sclerosis (ALS). TDP-43 has been identified as a major component of protein inclusions in the brain of patients with ALS; mutations in the corresponding gene (TARDBP) have also been identified. Although increased TDP-43 levels have been reported in the cerebrospinal fluid, plasma levels have not yet been assessed in patients with ALS. TDP-43 levels were quantified by sandwich ELISA in plasma of 219 patients and 100 controls. In addition, we sequenced exon 6 of TARDBP, and performed longitudinal TDP-43 plasma measurements in a subset of patients. Results showed that TDP-43 plasma levels were significantly increased in patients with ALS (p=0.023) and we found a positive correlation with age in patients and controls. Longitudinal measurements of TDP-43 plasma levels showed an increase in only one patient, with stable levels in five others. Three TARDBP variations were identified in the ALS group (1.7%), but the association with TDP-43 plasma levels was ambiguous. In conclusion, our data indicate that TDP-43 plasma levels may have potential as a marker for ALS. A genotype-phenotype relationship could not, however, be established in this cohort.

Dutch injection versus surgery trial in patients with carpal tunnel syndrome (DISTRICTS): protocol of a randomised controlled trial comparing two treatment strategies.

INTRODUCTION: Carpal tunnel syndrome (CTS) is the most common peripheral neuropathy. The optimal treatment strategy is still unknown. The objective of the Dutch Injection versus Surgery TRIal in patients with CTS (DISTRICTS) is to investigate if initial surgery of CTS results in a better clinical outcome and is more cost-effective when compared with initial treatment with corticosteroid injection. METHODS AND ANALYSIS: The DISTRICTS is an ongoing multicenter, open-label randomised controlled trial. Participants with CTS are randomised to treatment with surgery or with a corticosteroid injection. If needed, any additional treatments after this first treatment are allowed and these are not dictated by the study protocol. The primary outcome is the difference between the groups in the proportion of participants recovered at 18 months. Recovery is defined as having no or mild symptoms as measured with the 6-item carpal tunnel symptoms scale. Secondary outcome measurements are among others: time to recovery, hand function, patient satisfaction, quality of life, additional treatments, adverse events, and use of care and health-related costs. ETHICS AND DISSEMINATION: The study was approved by the Medical Ethical Committee of the Amsterdam University Medical Centers (study number 2017-171). Study results will be disseminated in peer-reviewed journals and conferences. TRIAL REGISTRATION NUMBER: ISRCTN Registry: 13164336.

No evidence of microbleeds in ALS patients at 7 Tesla MRI.

There have been several reports about disruption of the blood-spinal cord barrier (BSCB) and blood-brain barrier (BBB) in SOD1 mutant mice. Pathologically, microbleeds and hemosiderine deposits were found. We investigated patients with ALS for the occurrence of cerebral microbleeds with 7 Tesla MRI. Twelve patients with ALS and 12 age- and sex-matched healthy controls were studied. We performed T2*-weighed imaging which enables whole-brain in vivo detection of cerebral microbleeds and hemosiderin deposits in humans. No microbleeds were found in patients with ALS.

Patterns of symptom development in patients with motor neuron disease.

OBJECTIVE: To investigate whether symptom development in motor neuron disease (MND) is a random or organized process. METHODS: Six hundred patients with amyotrophic lateral sclerosis (ALS), upper motor neuron (UMN) or lower motor neuron (LMN) phenotypes were invited for a questionnaire concerning symptom development. A binomial test was used to examine distribution of symptoms from site of onset. Development of symptoms over time was evaluated by Kaplan-Meier analysis. RESULTS: There were 470 respondents (ALS = 254; LMN = 100; UMN = 116). Subsequent symptoms were more often in the contralateral limb following unilateral limb onset (ALS: arms p = 1.05 × 10-8, legs p < 2.86 × 10-15; LMN phenotype: arms p = 6.74 × 10-9, legs p = 6.26 × 10-6; UMN phenotype: legs p = 4.07 × 10-14). In patients with limb onset, symptoms occurred significantly faster in the contralateral limb, followed by the other limbs and lastly by the bulbar region. Patterns of non-contiguous symptom development were also reported: leg symptoms followed bulbar onset in 30%, and bulbar symptoms followed leg onset in 11% of ALS patients. CONCLUSIONS: Preferred spread of symptoms from one limb to the contralateral limb, and to adjacent sites appears to be a characteristic of MND phenotypes, suggesting that symptom spread is organized, possibly involving axonal connectivity. Non-contiguous symptom development, however, is not uncommon, and may involve other factors.

Meta-analysis of pharmacogenetic interactions in amyotrophic lateral sclerosis clinical trials.

OBJECTIVE: To assess whether genetic subgroups in recent amyotrophic lateral sclerosis (ALS) trials responded to treatment with lithium carbonate, but that the treatment effect was lost in a large cohort of nonresponders. METHODS: Individual participant data were obtained from 3 randomized trials investigating the efficacy of lithium carbonate. We matched clinical data with data regarding the UNC13A and C9orf72 genotype. Our primary outcome was survival at 12 months. On an exploratory basis, we assessed whether the effect of lithium depended on the genotype. RESULTS: Clinical data were available for 518 of the 606 participants. Overall, treatment with lithium carbonate did not improve 12-month survival (hazard ratio [HR] 1.0, 95% confidence interval [CI] 0.7-1.4; p = 0.96). Both the UNC13A and C9orf72 genotype were independent predictors of survival (HR 2.4, 95% CI 1.3-4.3; p = 0.006 and HR 2.5, 95% CI 1.1-5.2; p = 0.032, respectively). The effect of lithium was different for UNC13A carriers (p = 0.027), but not for C9orf72 carriers (p = 0.22). The 12-month survival probability for UNC13A carriers treated with lithium carbonate improved from 40.1% (95% CI 23.2-69.1) to 69.7% (95% CI 50.4-96.3). CONCLUSIONS: This study incorporated genetic data into past ALS trials to determine treatment effects in a genetic post hoc analysis. Our results suggest that we should reorient our strategies toward finding treatments for ALS, start focusing on genotype-targeted treatments, and standardize genotyping in order to optimize randomization and analysis for future clinical trials.

Neuroimaging as a New Diagnostic Modality in Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is characterized by progressive degeneration of upper and lower motor neurons, with variable involvement of extramotor brain regions. Currently, there are no established objective markers of upper motor neuron and extramotor involvement in ALS. Here, we review the potential diagnostic value of advanced neuroimaging techniques that are increasingly being used to study the brain in ALS. First, we discuss the role of different imaging modalities in our increasing understanding of ALS pathogenesis, and their potential to contribute to objective upper motor neuron biomarkers for the disease. Second, we discuss the challenges to be overcome and the required phases of diagnostic test development to translate imaging technology to clinical care. We also present examples of multidimensional imaging approaches to achieve high levels of diagnostic accuracy. Last, we address the role of neuroimaging in clinical therapeutic trials. Advanced neuroimaging techniques will continue to develop and offer significant opportunities to facilitate the development of new effective treatments for ALS.

Mind the gap: the mismatch between clinical and imaging metrics in ALS.

Advanced magnetic resonance imaging (MRI) techniques hold the promise to capture upper motor neuron loss and extramotor brain changes in amyotrophic lateral sclerosis (ALS) and as such deliver biomarkers relevant to diagnosis, prognosis and monitoring disease progression. However, a correlation between imaging parameters and clinical metrics has thus far been inconsistent across studies. We discuss the contributing factors to this clinical-imaging correlation gap as well as its implications for future research.

Subcortical structures in amyotrophic lateral sclerosis.

The aim of this study was to assess the involvement of deep gray matter, hippocampal subfields, and ventricular changes in patients with amyotrophic lateral sclerosis (ALS). A total of 112 ALS patients and 60 healthy subjects participated. High-resolution T1-weighted images were acquired using a 3T MRI scanner. Thirty-nine patients underwent a follow-up scan. Volumetric and shape analyses of subcortical structures were performed, measures were correlated with clinical parameters, and longitudinal changes were assessed. At baseline, reduced hippocampal volumes (left: p = 0.007; right: p = 0.011) and larger inferior lateral ventricles (left: p = 0.013; right: p = 0.041) were found in patients compared to healthy controls. Longitudinal analyses demonstrated a significant decrease in volume of the right cornu ammonis 2/3 and 4/dentate gyrus and left presubiculum (p = 0.002, p = 0.045, p < 0.001), and a significant increase in the ventricular volume in the lateral (left: p < 0.001; right: p < 0.001), 3rd (p < 0.001) and 4th (p = 0.001) ventricles. Larger ventricles were associated with a lower ALSFRS-R score (p = 0.021). In conclusion, ALS patients show signs of neurodegeneration of subcortical structures and ventricular enlargement. Subcortical involvement is progressive and correlates with clinical parameters, highlighting its role in the neurodegenerative process in ALS.

Brain morphologic changes in asymptomatic C9orf72 repeat expansion carriers.

OBJECTIVE: To investigate possible effects of the C9orf72 repeat expansion before disease onset, we assessed brain morphology in asymptomatic carriers. METHODS: Aiming to diminish the effects of genetic variation between subjects, apart from the C9orf72 repeat expansion, 16 carriers of the repeat expansion were compared with 23 noncarriers from the same large family with a history of amyotrophic lateral sclerosis (ALS). Cortical thickness, subcortical volumes, and white matter connectivity, as assessed from high-resolution T1-weighted and diffusion-weighted MRIs, were evaluated. For comparison, we included 14 C9orf72 carriers with ALS and 28 healthy, unrelated controls. RESULTS: We found temporal, parietal, and occipital regions to be thinner (p < 0.05) and the left caudate and putamen to be smaller (p < 0.05) in asymptomatic carriers compared with noncarriers. Cortical thinning of the primary motor cortex and decreased connectivity of white matter pathways (global, corticospinal tract, and corpus callosum) were observed in patients with C9orf72-associated ALS, but not in asymptomatic carriers. CONCLUSIONS: Asymptomatic C9orf72 carriers show cortical and subcortical differences compared with noncarriers from the same family, possibly effects of the C9orf72 repeat expansion on the brain. Of note, changes in the primary motor regions and motor-related tracts were found exclusively in patients with ALS, indicating that such motor changes may be a disease phenomenon.

Multimodal tract-based analysis in ALS patients at 7T: a specific white matter profile?

Our objective was to explore the value of additional MR contrasts in elucidating the decrease in fractional anisotropy (FA) as has been observed in the corticospinal tracts (CST) of patients with amyotrophic lateral sclerosis (ALS). Eleven patients and nine healthy control subjects were scanned at 3T and 7T MRI. Whole brain and tract specific comparison was performed of both diffusion weighted (3T), quantitative T1 (qT1), magnetization transfer ratio (MTR) and amide proton transfer weighted (APTw) imaging (7T). Results of whole brain comparison using histogram analyses showed no significant differences between patients and controls. Measures along the CST showed a significantly reduced FA together with a significantly increased diffusivity perpendicular to the tract direction in patients compared to controls. In addition, patients showed a small but significant increase in MTR values within the right CST. No significant changes were observed in qT1 and APTw values. In conclusion, our findings, based on a multimodal approach, revealed that the decrease in FA is most probably caused by an increased diffusivity perpendicular to the CST. This diffusivity profile, together with the increase in MTR is inconsistent with demyelination but consistent with an increase of free liquid spins in the white matter tissue.

Neuroimaging in amyotrophic lateral sclerosis.

The catastrophic system failure in amyotrophic lateral sclerosis is characterized by progressive neurodegeneration within the corticospinal tracts, brainstem nuclei and spinal cord anterior horns, with an extra-motor pathology that has overlap with frontotemporal dementia. The development of computed tomography and, even more so, MRI has brought insights into neurological disease, previously only available through post-mortem study. Although largely research-based, radionuclide imaging has continued to provide mechanistic insights into neurodegenerative disorders. The evolution of MRI to use advanced sequences highly sensitive to cortical and white matter structure, parenchymal metabolites and blood flow, many of which are now applicable to the spinal cord as well as the brain, make it a uniquely valuable tool for the study of a multisystem disorder such as amyotrophic lateral sclerosis. This comprehensive review considers the full range of neuroimaging techniques applied to amyotrophic lateral sclerosis over the last 25 years, the biomarkers they have revealed and future developments.

Impaired structural motor connectome in amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease selectively affecting upper and lower motor neurons. Patients with ALS suffer from progressive paralysis and eventually die on average after three years. The underlying neurobiology of upper motor neuron degeneration and its effects on the complex network of the brain are, however, largely unknown. Here, we examined the effects of ALS on the structural brain network topology in 35 patients with ALS and 19 healthy controls. Using diffusion tensor imaging (DTI), the brain network was reconstructed for each individual participant. The connectivity of this reconstructed brain network was compared between patients and controls using complexity theory without--a priori selected--regions of interest. Patients with ALS showed an impaired sub-network of regions with reduced white matter connectivity (p = 0.0108, permutation testing). This impaired sub-network was strongly centered around primary motor regions (bilateral precentral gyrus and right paracentral lobule), including secondary motor regions (bilateral caudal middle frontal gyrus and pallidum) as well as high-order hub regions (right posterior cingulate and precuneus). In addition, we found a significant reduction in overall efficiency (p = 0.0095) and clustering (p = 0.0415). From our findings, we conclude that upper motor neuron degeneration in ALS affects both primary motor connections as well as secondary motor connections, together composing an impaired sub-network. The degenerative process in ALS was found to be widespread, but interlinked and targeted to the motor connectome.