1
|
Rajagopalan V, Pioro EP. Graph theory network analysis reveals widespread white matter damage in brains of patients with classic ALS. Amyotroph Lateral Scler Frontotemporal Degener 2024:1-8. [PMID: 39373307 DOI: 10.1080/21678421.2024.2410281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Revised: 08/20/2024] [Accepted: 09/23/2024] [Indexed: 10/08/2024]
Abstract
Objective: Amyotrophic lateral sclerosis (ALS) exhibits several different presentations and clinical phenotypes. Of these, classic ALS (ALS-Cl), which is the most common phenotype, presents with relatively equal amounts of upper motor neuron and lower motor neuron signs. Magnetic resonance imaging (MRI) provides a noninvasive way to assess central nervous system damage in these patients. To our knowledge no study is available where exploratory whole brain grey matter (GM) and white matter (WM) network analysis is performed considering only the ALS-Cl subgroup of ALS patients. Methods: GM voxel-based morphometry analysis and WM network analysis using graph theory was performed in the MRI dataset of 14 neurologic controls and 25 ALS-Cl patients. Results and Conclusions: No significant GM differences were observed between ALS-Cl and neurologic controls. WM network revealed significant (p < 0.05) reduction and increase in degree measure in several extramotor brain regions of ALS-Cl patients. Both global and local graph metrics revealed significant abnormal values in ALS-Cl patients when compared to neurologic controls. Significant WM changes in ALS-Cl patients with no significant GM changes suggest that neurodegeneration may onset as an "axonopathy" in this ALS subtype.
Collapse
Affiliation(s)
- Venkateswaran Rajagopalan
- Department of Electrical and Electronics Engineering, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Hyderabad, India
| | - Erik P Pioro
- Department of Neurology, Neuromuscular Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA, and
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, USA
| |
Collapse
|
2
|
Zamani A, Thomas E, Wright DK. Sex biology in amyotrophic lateral sclerosis. Ageing Res Rev 2024; 95:102228. [PMID: 38354985 DOI: 10.1016/j.arr.2024.102228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 02/09/2024] [Accepted: 02/09/2024] [Indexed: 02/16/2024]
Abstract
Although sex differences in amyotrophic lateral sclerosis (ALS) have not been studied systematically, numerous clinical and preclinical studies have shown sex to be influential in disease prognosis. Moreover, with the development of advanced imaging tools, the difference between male and female brain in structure and function and their response to neurodegeneration are more definitive. As discussed in this review, ALS patients exhibit a sex bias pertaining to the features of the disease, and their clinical, pathological, (and pathophysiological) phenotypes. Several epidemiological studies have indicated that this sex disparity stems from various aetiologies, including sex-specific brain structure and neural functioning, genetic predisposition, age, gonadal hormones, susceptibility to traumatic brain injury (TBI)/head trauma and lifestyle factors.
Collapse
Affiliation(s)
- Akram Zamani
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia.
| | - Emma Thomas
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia
| | - David K Wright
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia
| |
Collapse
|
3
|
Rajagopalan V, Pioro EP. Graph network measures reveal distinct white matter abnormalities in motor and extra-motor brain regions of two UMN-predominant ALS subtypes. J Neurol Sci 2023; 452:120765. [PMID: 37672915 DOI: 10.1016/j.jns.2023.120765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 08/04/2023] [Accepted: 08/08/2023] [Indexed: 09/08/2023]
Abstract
BACKGROUND Routine clinical magnetic resonance imaging (MRI) shows bilateral corticospinal tract (CST) hyperintensity in some patients with upper motor neuron (UMN)-predominant ALS (ALS-CST+) but not in others (ALS-CST-). Although, similar in their UMN features, the ALS-CST+ patient group is significantly younger in age, has faster disease progression and shorter survival than the ALS-CST- patient group. Reasons for the differences are unclear. METHOD In order to evaluate more objective MRI measures of these ALS subgroups, we used diffusion tensor images (DTI) obtained using single shot echo planar imaging sequence from 1.5 T Siemens MRI Scanner. We performed an exploratory whole brain white matter (WM) network analysis using graph theory approach on 45 ALS patients (ALS-CST+) (n = 21), and (ALS-CST-) (n = 24) and neurological controls (n = 14). RESULTS Significant (p < 0.05) differences in nodal degree measure between ALS patients and controls were observed in motor and extra motor regions, supplementary motor area, subcortical WM regions, cerebellum and vermis. Importantly, WM network abnormalities were significantly (p < 0.05) different between ALS-CST+ and ALS-CST- subgroups. Compared to neurologic controls, both ALS subgroups showed hubs in the right superior occipital gyrus and cuneus as well as significantly (p < 0.05) reduced small worldness supportive of WM network damage. CONCLUSIONS Significant differences between ALS-CST+ and ALS-CST- subgroups of WM network abnormalities, age of onset, symptom duration prior to MRI, and progression rate suggest these patients represent distinct clinical phenotypes and possibly pathophysiologic mechanisms of ALS.
Collapse
Affiliation(s)
- Venkateswaran Rajagopalan
- Department of Electrical and Electronics Engineering, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Hyderabad 500078, India
| | - Erik P Pioro
- Neuromuscular Center, Department of Neurology, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
| |
Collapse
|
4
|
Rajagopalan V, Chaitanya KG, Pioro EP. Quantitative Brain MRI Metrics Distinguish Four Different ALS Phenotypes: A Machine Learning Based Study. Diagnostics (Basel) 2023; 13:diagnostics13091521. [PMID: 37174914 PMCID: PMC10177762 DOI: 10.3390/diagnostics13091521] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/20/2023] [Accepted: 04/12/2023] [Indexed: 05/15/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease whose diagnosis depends on the presence of combined lower motor neuron (LMN) and upper motor neuron (UMN) degeneration. LMN degeneration assessment is aided by electromyography, whereas no equivalent exists to assess UMN dysfunction. Magnetic resonance imaging (MRI) is primarily used to exclude conditions that mimic ALS. We have identified four different clinical/radiological phenotypes of ALS patients. We hypothesize that these ALS phenotypes arise from distinct pathologic processes that result in unique MRI signatures. To our knowledge, no machine learning (ML)-based data analyses have been performed to stratify different ALS phenotypes using MRI measures. During routine clinical evaluation, we obtained T1-, T2-, PD-weighted, diffusion tensor (DT) brain MRI of 15 neurological controls and 91 ALS patients (UMN-predominant ALS with corticospinal tract CST) hyperintensity, n = 21; UMN-predominant ALS without CST hyperintensity, n = 26; classic ALS, n = 23; and ALS patients with frontotemporal dementia, n = 21). From these images, we obtained 101 white matter (WM) attributes (including DT measures, graph theory measures from DT and fractal dimension (FD) measures using T1-weighted), 10 grey matter (GM) attributes (including FD based measures from T1-weighted), and 10 non-imaging attributes (2 demographic and 8 clinical measures of ALS). We employed classification and regression tree, Random Forest (RF) and also artificial neural network for the classifications. RF algorithm provided the best accuracy (70-94%) in classifying four different phenotypes of ALS patients. WM metrics played a dominant role in classifying different phenotypes when compared to GM or clinical measures. Although WM measures from both right and left hemispheres need to be considered to identify ALS phenotypes, they appear to be differentially affected by the degenerative process. Longitudinal studies can confirm and extend our findings.
Collapse
Affiliation(s)
- Venkateswaran Rajagopalan
- Department of Electrical and Electronics Engineering, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Hyderabad 500078, India
| | - Krishna G Chaitanya
- Department of Electrical and Electronics Engineering, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Hyderabad 500078, India
| | - Erik P Pioro
- Neuromuscular Center, Department of Neurology, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| |
Collapse
|
5
|
Rajagopalan V, Pioro EP. Graph theory network analysis provides brain MRI evidence of a partial continuum of neurodegeneration in patients with UMN-predominant ALS and ALS-FTD. Neuroimage Clin 2022; 35:103037. [PMID: 35597032 PMCID: PMC9123271 DOI: 10.1016/j.nicl.2022.103037] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 04/20/2022] [Accepted: 05/04/2022] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Our routine clinical neuroimaging showed hyperintense signal along the corticospinal tract only in some but not all patients with upper motor neuron (UMN)-predominant ALS. ALS patients with CST hyperintensity (ALS-CST+) and those without CST hyperintensity (ALS-CST-) present with nearly identical clinical UMN-predominant symptoms. Some previous studies have suggested that ALS patients with frontotemporal dementia (FTD) are on a continuum with ALS patients without FTD, while others have not. We aimed to determine whether: (a) ALS-CST+, ALS-CST-, and ALS-FTD patients show differential sites of predominant neurodegeneration occurring primarily cortically in the perikaryon or subcortically in the white matter (WM), or (b) UMN-predominant ALS is on a continuum with ALS-FTD. METHODS Exploratory whole brain grey matter (GM) voxel-based morphometry and WM network analysis using graph theory approach were performed. In this exploratory study, MRI data from 58 ALS patients (ALS-FTD, n = 15; ALS-CST+, n = 19; ALS-CST-, n = 24) and 14 neurological controls were obtained. RESULTS Significant differences in degree measures (evaluating WM networks) were observed between ALS patients and controls in frontal, motor, extra-motor, subcortical, and cerebellar regions. GM atrophy was observed only in the ALS-FTD subgroup and not in the other ALS subgroups. CONCLUSION Although WM network disruption by the ALS disease process showed different patterns between ALS-CST+, ALS-CST-, and ALS-FTD subgroups, there were some overlaps, particularly in prefrontal regions and between ALS-CST+ and ALS-FTD patients. Our preliminary findings suggest a partial continuum of, at least, WM degeneration between these subgroups with predominance of cortical pathology ("neuronopathy") in ALS-FTD patients and subcortical WM pathology ("axonopathy") in ALS-CST+ and ALS-CST- patients.
Collapse
Affiliation(s)
- Venkateswaran Rajagopalan
- Department of Electrical and Electronics Engineering, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Hyderabad 500078, India
| | - Erik P Pioro
- Neuromuscular Center, Department of Neurology, Neurological Institute, United States; Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, United States; Neuromuscular Division, The Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, United States.
| |
Collapse
|
6
|
Corticospinal Tract and Related Grey Matter Morphometric Shape Analysis in ALS Phenotypes: A Fractal Dimension Study. Brain Sci 2021; 11:brainsci11030371. [PMID: 33799358 PMCID: PMC8001972 DOI: 10.3390/brainsci11030371] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/10/2021] [Accepted: 03/10/2021] [Indexed: 11/30/2022] Open
Abstract
A pathological hallmark of amyotrophic lateral sclerosis (ALS) is corticospinal tract (CST) degeneration resulting in upper motor neuron (UMN) dysfunction. No quantitative test is available to easily assess UMN pathways. Brain neuroimaging in ALS promises to potentially change this through identifying biomarkers of UMN dysfunction that may accelerate diagnosis and track disease progression. Fractal dimension (FD) has successfully been used to quantify brain grey matter (GM) and white matter (WM) shape complexity in various neurological disorders. Therefore, we investigated CST and whole brain GM and WM morphometric changes using FD analyses in ALS patients with different phenotypes. We hypothesized that FD would detect differences between ALS patients and neurologic controls and even between the ALS subgroups. Neuroimaging was performed in neurologic controls (n = 14), and ALS patients (n = 75). ALS patients were assigned into four groups based on their clinical or radiographic phenotypes. FD values were estimated for brain WM and GM structures. Patients with ALS and frontotemporal dementia (ALS-FTD) showed significantly higher CST FD values and lower primary motor and sensory cortex GM FD values compared to other ALS groups. No other group of ALS patients revealed significant FD value changes when compared to neurologic controls or with other ALS patient groups. These findings support a more severe disease process in ALS-FTD patients compared to other ALS patient groups. FD value measures may be a sensitive index to evaluate GM and WM (including CST) degeneration in ALS patients.
Collapse
|
7
|
Pioro EP, Turner MR, Bede P. Neuroimaging in primary lateral sclerosis. Amyotroph Lateral Scler Frontotemporal Degener 2020; 21:18-27. [PMID: 33602015 DOI: 10.1080/21678421.2020.1837176] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 10/08/2020] [Accepted: 10/09/2020] [Indexed: 12/15/2022]
Abstract
Increased interest in the underlying pathogenesis of primary lateral sclerosis (PLS) and its relationship to amyotrophic lateral sclerosis (ALS) has corresponded to a growing number of CNS imaging studies, especially in the past decade. Both its rarity and uncertainty of definite diagnosis prior to 4 years from symptom onset have resulted in PLS being less studied than ALS. In this review, we highlight most relevant papers applying magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), and positron emission tomography (PET) to analyzing CNS changes in PLS, often in relation to ALS. In patients with PLS, mostly brain, but also spinal cord has been evaluated since significant neurodegeneration is essentially restricted to upper motor neuron (UMN) structures and related pathways. Abnormalities of cortex and subcortical white matter tracts have been identified by structural and functional MRI and MRS studies, while metabolic and cell-specific changes in PLS brain have been revealed using various PET radiotracers. Future neuroimaging studies will continue to explore the interface between the PLS-ALS continuum, identify more changes unique to PLS, apply novel MRI and MRS sequences showing greater structural and neurochemical detail, as well as expand the repertoire of PET radiotracers that reveal various cellular pathologies. Neuroimaging has the potential to play an important role in the evaluation of novel therapies for patients with PLS.
Collapse
Affiliation(s)
- Erik P Pioro
- Section of ALS & Related Disorders, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Martin R Turner
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Peter Bede
- Computational Neuroimaging Group, Trinity College Dublin, Dublin, Ireland
| |
Collapse
|
8
|
Rajagopalan V, Pioro EP. 2-Deoxy-2-[ 18 F]fluoro-d-glucose positron emission tomography, cortical thickness and white matter graph network abnormalities in brains of patients with amyotrophic lateral sclerosis and frontotemporal dementia suggest early neuronopathy rather than axonopathy. Eur J Neurol 2020; 27:1904-1912. [PMID: 32432818 DOI: 10.1111/ene.14332] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 05/13/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND PURPOSE Amyotrophic lateral sclerosis (ALS) is a motor neuron disorder, although extra-motor degeneration is well recognized, especially in frontotemporal regions manifested as ALS with frontotemporal dementia (ALS-FTD). Previous neuroimaging studies of the brains of ALS-FTD patients have measured abnormalities of either grey matter (GM) or white matter (WM) structures but not of both together. Therefore, the aim was to evaluate both GM and WM in the same ALS-FTD patient using functional and structural neuroimaging. By doing so, insights could be gained into whether neurodegeneration in ALS-FTD is primarily a neuronopathy or axonopathy. METHODS After high-resolution brain 2-deoxy-2-[18 F]fluoro-D-glucose (18 F-FDG) positron emission tomography (PET) and magnetic resonance imaging (MRI) scans were obtained in ALS-FTD patients and in age- and sex-matched neurological controls, changes in metabolic rate, cortical thickness (CT) and WM network analysis using graph theory were analyzed. RESULTS Significant reductions in 18 F-FDG PET metabolism, CT and WM connections were observed in motor and extra-motor brain regions of ALS-FTD patients compared to controls. Both CT and underlying WM networks were abnormal in frontal, temporal, parietal and occipital lobes of ALS-FTD patients with 86 of 90 brain regions showing reductions of CT. CONCLUSION Abnormalities in significantly fewer WM networks underlying the affected cortical regions suggest that neurodegeneration in brains of ALS-FTD patients is primarily a 'neuronopathy' rather than an 'axonopathy.'
Collapse
Affiliation(s)
- V Rajagopalan
- Department of Electrical and Electronics Engineering, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Hyderabad, India.,Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - E P Pioro
- Neuromuscular Center, Department of Neurology, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA.,Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| |
Collapse
|
9
|
Baek SH, Park J, Kim YH, Seok HY, Oh KW, Kim HJ, Kwon YJ, Sim Y, Tae WS, Kim SH, Kim BJ. Usefulness of diffusion tensor imaging findings as biomarkers for amyotrophic lateral sclerosis. Sci Rep 2020; 10:5199. [PMID: 32251314 PMCID: PMC7090054 DOI: 10.1038/s41598-020-62049-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 03/08/2020] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease. However, no reliable biomarkers have been identified to represent the clinical status. This study aimed to investigate whether diffusion tensor imaging (DTI) findings are useful imaging biomarkers to indicate the clinical status of ALS patients. Ninety-six probable or definite ALS cases and 47 age- and sex-matched, normal controls were enrolled. Demographic and clinical data were collected at the time of DTI. DTI data were acquired using a 3-Tesla magnetic resonance imaging scanner and analysed by voxel-wise statistical analyses for fractional anisotropy, axial diffusivity, radial diffusivity, mean diffusivity, and mode of anisotropy. Compared with the healthy control group, the ALS group had significant differences in DTI scalars in the diffuse tracts of the brain, which was predominant in the corticospinal tract at the brainstem and cerebellar peduncle area. Furthermore, the DTI values correlated with the ALS functional rating scale-revised (ALSFRS-R) scores and the delta ALSFRS-R score representing the rate of disease progression. The subgroup analysis revealed a more severe and widespread brain degeneration was observed in rapidly progressive ALS. Therefore, our results suggest that DTI findings are useful as imaging biomarkers for evaluating the clinical severity and rate of disease progression in ALS.
Collapse
Affiliation(s)
- Seol-Hee Baek
- Department of Neurology, Korea University Anam Hospital, Korea University College of Medicine, Seoul, 02841, Republic of Korea
| | - Jinseok Park
- Department of Neurology, Hanyang University College of Medicine, Seoul, 04763, Republic of Korea
| | - Yoo Hwan Kim
- Department of Neurology, College of Medicine, Hallym University Sacred Heart Hospital, Anyang, 14068, Republic of Korea
| | - Hung Youl Seok
- Department of Neurology, Keimyung University School of Medicine, Daegu, 42601, Republic of Korea
| | - Ki-Wook Oh
- Department of Neurology, Hanyang University College of Medicine, Seoul, 04763, Republic of Korea
| | - Hee-Jin Kim
- Department of Neurology, Hanyang University College of Medicine, Seoul, 04763, Republic of Korea
| | - Ye-Ji Kwon
- Department of Neurology, Korea University Anam Hospital, Korea University College of Medicine, Seoul, 02841, Republic of Korea
| | - Youngbo Sim
- Brain Convergence Research Center, Korea University Anam Hospital, Korea University Medical Center, Seoul, 02841, Republic of Korea
| | - Woo-Suk Tae
- Brain Convergence Research Center, Korea University Anam Hospital, Korea University Medical Center, Seoul, 02841, Republic of Korea
| | - Seung Hyun Kim
- Department of Neurology, Hanyang University College of Medicine, Seoul, 04763, Republic of Korea.
| | - Byung-Jo Kim
- Department of Neurology, Korea University Anam Hospital, Korea University College of Medicine, Seoul, 02841, Republic of Korea. .,Brain Convergence Research Center, Korea University Anam Hospital, Korea University Medical Center, Seoul, 02841, Republic of Korea.
| |
Collapse
|
10
|
Sarica A, Valentino P, Nisticò R, Barone S, Pucci F, Quattrone A, Cerasa A, Quattrone A. Assessment of the Corticospinal Tract Profile in Pure Lower Motor Neuron Disease: A Diffusion Tensor Imaging Study. NEURODEGENER DIS 2019; 19:128-138. [PMID: 31715609 DOI: 10.1159/000503970] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 10/06/2019] [Indexed: 11/19/2022] Open
Abstract
AIM The aim of this study was to evaluate the corticospinal tract (CST) diffusion profile in pure lower motor neuron disease (pLMND) patients who at baseline did not show any clinical or electrophysiological involvement of upper motor neurons (UMN), and in amyotrophic lateral sclerosis (ALS) patients. MATERIALS AND METHODS Fifteen ALS patients with delayed central motor conduction time (CMCT) and 14 pLMND patients with normal CMCT were enrolled together with 15 healthy controls. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) maps were obtained. The tract profile of CST was reconstructed with the automated fiber quantification tool and its diffusion properties were quantified voxel-by-voxel and then compared pairwise between groups. Moreover, a random forest (RF) classifier was trained to evaluate the ability of CST diffusion metrics in distinguishing pairwise the groups from the controls. RESULTS ALS patients presented wide microstructural abnormalities in the entire CST as assessed by FA decrease and RD increase while pLMND patients showed focal FA decrease and a larger AD increase in the cerebral peduncle and posterior limb of the internal capsule in comparison with controls. RF revealed that diffusion tensor imaging (DTI) metrics accurately distinguished ALS patients and pLMND patients from controls (96.67 and 95.71% accuracy, respectively). CONCLUSIONS Our study demonstrates that the CST was impaired in both ALS and pLMND patients, thus suggesting that DTI metrics are a reliable tool in detecting subtle changes of UMN in pLMND patients, also in the absence of clinical and CMCT abnormalities.
Collapse
Affiliation(s)
- Alessia Sarica
- Neuroscience Research Centre,University Magna Graecia of Catanzaro, Catanzaro, Italy
| | - Paola Valentino
- Institute of Neurology, University Magna Graecia of Catanzaro, Catanzaro, Italy
| | - Rita Nisticò
- Institute of Bioimaging and Molecular Physiology (IBFM), National Research Council, Catanzaro, Italy
| | - Stefania Barone
- Institute of Neurology, University Magna Graecia of Catanzaro, Catanzaro, Italy
| | - Franco Pucci
- Institute of Neurology, University Magna Graecia of Catanzaro, Catanzaro, Italy
| | - Andrea Quattrone
- Institute of Neurology, University Magna Graecia of Catanzaro, Catanzaro, Italy
| | - Antonio Cerasa
- Institute of Bioimaging and Molecular Physiology (IBFM), National Research Council, Catanzaro, Italy
| | - Aldo Quattrone
- Neuroscience Research Centre,University Magna Graecia of Catanzaro, Catanzaro, Italy, .,Institute of Bioimaging and Molecular Physiology (IBFM), National Research Council, Catanzaro, Italy,
| |
Collapse
|
11
|
Theme 8 Clinical imaging and electrophysiology. Amyotroph Lateral Scler Frontotemporal Degener 2019; 20:246-261. [DOI: 10.1080/21678421.2019.1646996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
12
|
Rajagopalan V, Pioro EP. Unbiased MRI Analyses Identify Micropathologic Differences Between Upper Motor Neuron-Predominant ALS Phenotypes. Front Neurosci 2019; 13:704. [PMID: 31354413 PMCID: PMC6639827 DOI: 10.3389/fnins.2019.00704] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 06/21/2019] [Indexed: 11/13/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is an incurable and progressively fatal neurodegenerative disease that manifests with distinct clinical phenotypes, which are seen in neuroimaging, and clinical studies. T2- and proton density (PD)-weighted magnetic resonance imaging (MRI) displays hyperintense signal along the corticospinal tract (CST) in some ALS patients with upper motor neuron (UMN)-predominant signs. These patients tend to be younger and have significantly faster disease progression. We hypothesize that such ALS patients with CST hyperintensity (ALS-CST+) comprise a clinical subtype distinct from other ALS subtypes, namely patients with UMN-predominant ALS without CST hyperintensity, classic ALS, and ALS with frontotemporal dementia (FTD). Novel approaches such as fractal dimension analysis on conventional MRI (cMRI) and advanced MR techniques such as diffusion tensor imaging (DTI) reveal significant differences between ALS-CST+ and the aforementioned ALS subtypes. Our unbiased neuroimaging studies demonstrate that the ALS-CST+ group, which can be initially identified by T2-, PD-, and FLAIR-weighted cMRI, is distinctive and distinguishable from other ALS subtypes with possible differences in disease pathogenesis.
Collapse
Affiliation(s)
- Venkateswaran Rajagopalan
- Department of Electrical and Electronics Engineering, Birla Institute of Technology and Science, Pilani, Hyderabad, India.,Department of Biomedical Engineering, ND2, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Erik P Pioro
- Department of Neurology, Neuromuscular Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, United States.,Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| |
Collapse
|
13
|
Abstract
The past decade has seen tremendous efforts in biomarker discovery and validation for neurodegenerative diseases. The source and type of biomarkers has continued to grow for central nervous system diseases, from biofluid-based biomarkers (blood or cerebrospinal fluid (CSF)), to nucleic acids, tissue, and imaging. While DNA remains a predominant biomarker used to identify familial forms of neurodegenerative diseases, various types of RNA have more recently been linked to familial and sporadic forms of neurodegenerative diseases during the past few years. Imaging approaches continue to evolve and are making major contributions to target engagement and early diagnostic biomarkers. Incorporation of biomarkers into drug development and clinical trials for neurodegenerative diseases promises to aid in the development and demonstration of target engagement and drug efficacy for neurologic disorders. This review will focus on recent advancements in developing biomarkers for clinical utility in Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS).
Collapse
Affiliation(s)
| | - Robert Bowser
- Iron Horse Diagnostics, Inc., Scottsdale, AZ, 85255, USA.
- Divisions of Neurology and Neurobiology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, 350 W Thomas Rd, Phoenix, AZ, 85013, USA.
| |
Collapse
|
14
|
Beyond fractional anisotropy in amyotrophic lateral sclerosis: the value of mean, axial, and radial diffusivity and its correlation with electrophysiological conductivity changes. Neuroradiology 2018; 60:505-515. [PMID: 29564498 DOI: 10.1007/s00234-018-2012-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Accepted: 02/26/2018] [Indexed: 01/06/2023]
Abstract
PURPOSE This paper aims to analyze the contribution of mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) in the detection of microstructural abnormalities in amyotrophic lateral sclerosis (ALS) and to evaluate the degree of agreement between structural and functional changes through concomitant diffusion tensor imaging (DTI), transcranial magnetic stimulation (TMS), and clinical assessment. METHODS Fourteen patients with ALS and 11 healthy, age- and gender-matched controls were included. All participants underwent magnetic resonance imaging including DTI. TMS was additionally performed in ALS patients. Differences in the distribution of DTI-derived measures were assessed using tract-based spatial statistical (TBSS) and volume of interest (VOI) analyses. Correlations between clinical, imaging, and neurophysiological findings were also assessed through TBSS. RESULTS ALS patients showed a significant increase in AD and MD involving the corticospinal tract (CST) and the pre-frontal white matter in the right posterior limb of the internal capsule (p < 0.05) when compared to the control group using TBSS, confirmed by VOI analyses. VOI analyses also showed increased AD in the corpus callosum (p < 0.05) in ALS patients. Fractional anisotropy (FA) in the right CST correlated significantly with upper motor neuron (UMN) score (r = - 0.79, p < 0.05), and right abductor digiti minimi central motor conduction time was highly correlated with RD in the left posterior internal capsule (r = - 0.81, p < 0.05). No other significant correlation was found. CONCLUSION MD, AD, and RD, besides FA, are able to further detect and characterize neurodegeneration in ALS. Furthermore, TMS and DTI appear to have a role as complementary diagnostic biomarkers of UMN dysfunction.
Collapse
|
15
|
Rajagopalan V, Pioro EP. Differential involvement of corticospinal tract (CST) fibers in UMN-predominant ALS patients with or without CST hyperintensity: A diffusion tensor tractography study. NEUROIMAGE-CLINICAL 2017; 14:574-579. [PMID: 28337412 PMCID: PMC5349615 DOI: 10.1016/j.nicl.2017.02.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 02/20/2017] [Accepted: 02/21/2017] [Indexed: 11/25/2022]
Abstract
Diagnosis of amyotrophic lateral sclerosis (ALS) depends on clinical evidence of combined upper motor neuron (UMN) and lower motor neuron (LMN) degeneration, although ALS patients can present with features predominantly of one or the other. Some UMN-predominant patients show hyperintense signal along the intracranial corticospinal tract (CST) on T2- and proton density (PD)-weighted images (ALS-CST +), and appear to have faster disease progression when compared to those without CST hyperintensity (ALS-CST -). The reason for this is unknown. We hypothesized that diffusion tensor tractography (DTT) would reveal differences in DTI abnormalities along the intracranial CST between these two patient subgroups. Clinical DTI scans were obtained at 1.5T in 14 neurologic controls and 45 ALS patients categorized into two UMN phenotypes based on clinical measures and MRI. DTT was used to quantitatively assess the CST in control and ALS groups. DTT revealed subcortical loss ('truncation') of virtual motor CST fibers (presumably) projecting from the precentral gyrus (PrG) in ALS patients but not in controls; in contrast, virtual fibers (presumably) projecting to the adjacent postcentral gyrus (PoG) were spared. No significant differences in virtual CST fiber length were observed between controls and ALS patients. However, the frequency of CST truncation was significantly higher in the ALS-CST + subgroup (9 of 21) than in the ALS-CST - subgroup (4 of 24; p = 0.049), suggesting this finding could differentiate these ALS subgroups. Also, because virtual CST truncation occurred only in the ALS patient group and not in the control group (p = 0.018), this DTT finding could prove to be a diagnostic biomarker of ALS. Significantly shorter disease duration and faster disease progression rate were observed in ALS patients with CST fiber truncation than in those without (p < 0.05). DTI metrics of fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) were also determined in four regions of interest (ROIs) along the CST, namely: cerebral peduncle (CP), posterior limb of internal capsule (PLIC), centrum semiovale at top of lateral ventricle (CSoLV) and subcortical to primary motor cortex (subPMC). Of note, FA values along the left hemisphere virtual CST tract were significantly different between controls and ALS-CST + patients (p < 0.05) only at the PLIC level, but not at the CSoLV or subPMC level. Also, no significant differences in FA values were observed between ALS subgroups or between control and ALS-CST - groups (p > 0.05) in any of the ROIs. In addition, comparing FA values between ALS patients with CST truncation and those without in the aforementioned four ROIs, revealed no significant differences in either hemisphere. However, visual evaluation of DTT was able to identify UMN degeneration in patients with ALS, particularly in those with a more aggressive clinical disease course and possibly different pathologic processes.
Collapse
Key Words
- ALS
- ALS, Amyotrophic lateral sclerosis
- CNS, Central nervous system
- CP, Cerebral peduncle
- CST, Corticospinal tract
- CSoLV, Centrum semiovale at top of lateral ventricle
- DTI
- DTI, Diffusion tensor imaging
- DTT, Diffusion tensor tractography
- DW, Diffusion weighted
- Diffusion tensor tractography
- EMG, Electromyography
- EPI, Echo planar imaging
- FA, Fractional anisotropy
- FLAIR, Fluid attenuated inversion recovery
- FSE, Fast spin echo
- LMN, Lower motor neuron
- MD, Mean diffusivity
- MR, Magnetic resonance
- MRI, Magnetic resonance imaging
- PD, Proton density
- PLIC, Posterior limb of the internal capsule
- PMC, Primary motor cortex
- PSC, Primary sensory cortex
- Phenotypes
- PoG, Postcentral gyrus
- PrG, Precentral gyrus
- ROI, Region of interest
- SNR, Signal-to-noise ratio
- SS-EPI, Single shot echo planar imaging
- SubPMC, Subcortical to primary motor cortex
- TE, Echo time
- TR, Repetition time
- UMN, Upper motor neuron
- cMRI, Conventional MRI
Collapse
Affiliation(s)
- Venkateswaran Rajagopalan
- Department of Electrical and Electronics Engineering, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Hyderabad, 500078, India; Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, United States
| | - Erik P Pioro
- Neuromuscular Center, Department of Neurology, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, United States; Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, United States
| |
Collapse
|
16
|
Brain Parenchymal Fraction: A Relatively Simple MRI Measure to Clinically Distinguish ALS Phenotypes. BIOMED RESEARCH INTERNATIONAL 2015; 2015:693206. [PMID: 26783524 PMCID: PMC4691452 DOI: 10.1155/2015/693206] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Revised: 11/19/2015] [Accepted: 11/23/2015] [Indexed: 11/17/2022]
Abstract
Even though neuroimaging and clinical studies indicate that amyotrophic lateral sclerosis (ALS) manifests with distinct clinical phenotypes, no objective test exists to assess upper motor degeneration in ALS. There is great interest in identifying biomarkers of ALS to allow earlier diagnosis and to recognize disease subtypes. Current quantitative neuroimaging techniques such as T2 relaxometry and diffusion tensor imaging are time-consuming to use in clinical settings due to extensive postprocessing requirements. Therefore, we aimed to study the potential role of brain parenchymal fraction (BPF) as a relatively simple quantitative measure for distinguishing ALS phenotypes. T1-weighted MR images of brain were obtained in 15 neurological controls and 88 ALS patients categorized into 4 distinct clinical phenotypes, upper motor neuron- (UMN-) predominant ALS patients with/without corticospinal tract (CST) hyperintensity on T2/PD-weighted images, classic ALS, and ALS with frontotemporal dementia (ALS-FTD). BPF was calculated using intracranial grey matter, white matter, and cerebrospinal fluid volumes obtained in control and ALS subgroups using SPM8 software. Only ALS-FTD patients had significant reduction in BPF when compared to controls and nondemented ALS patients. Correlation of clinical measures such as disease duration with BPF further supports the view that the BPF could be a potential biomarker for clinical diagnosis of ALS-FTD patients.
Collapse
|
17
|
Verstraete E, Foerster BR. Neuroimaging as a New Diagnostic Modality in Amyotrophic Lateral Sclerosis. Neurotherapeutics 2015; 12:403-16. [PMID: 25791072 PMCID: PMC4404464 DOI: 10.1007/s13311-015-0347-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
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.
Collapse
Affiliation(s)
- Esther Verstraete
- />Department of Neurology, Rudolf Magnus Institute of Neuroscience, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Bradley R. Foerster
- />Department of Radiology, University of Michigan, 1500 East Medical Center Drive, Ann Arbor, MI 48109 USA
- />Ann Arbor VA Healthcare System, Ann Arbor, MI USA
- />Russell H. Morgan Department of Radiology, Johns Hopkins University, Baltimore, MD USA
| |
Collapse
|
18
|
Chiò A, Pagani M, Agosta F, Calvo A, Cistaro A, Filippi M. Neuroimaging in amyotrophic lateral sclerosis: insights into structural and functional changes. Lancet Neurol 2014; 13:1228-40. [PMID: 25453462 DOI: 10.1016/s1474-4422(14)70167-x] [Citation(s) in RCA: 160] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In the past two decades, structural and functional neuroimaging findings have greatly modified longstanding notions regarding the pathophysiology of amyotrophic lateral sclerosis (ALS). Neuroimaging studies have shown that anatomical and functional lesions spread beyond precentral cortices and corticospinal tracts, to include the corpus callosum; frontal, sensory, and premotor cortices; thalamus; and midbrain. Both MRI and PET studies have shown early and diffuse loss of inhibitory cortical interneurons in the motor cortex (increased levels of functional connectivity and loss of GABAergic neurons, respectively) and diffuse gliosis in white-matter tracts. In ALS endophenotypes, neuroimaging has also shown a diverse spreading of lesions and a dissimilar impairment of functional and structural connections. A possible role of PET in the diagnosis of ALS has recently been proposed. However, most neuroimaging studies have pitfalls, such as a small number and poor clinical characterisation of patients, absence of adequate controls, and scarcity of longitudinal assessments. Studies involving international collaborations, standardised assessments, and large patient cohorts will overcome these shortcomings and provide further insight into the pathogenesis of ALS.
Collapse
Affiliation(s)
- Adriano Chiò
- ALS Center, "Rita Levi Montalcini" Department of Neuroscience, University of Turin, Turin, Italy.
| | - Marco Pagani
- Institute of Cognitive Sciences and Technologies, Consiglio Nazionale delle Ricerche (CNR), Rome, Italy; Department of Nuclear Medicine, Karolinska Hospital, Stockholm, Sweden
| | - Federica Agosta
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| | - Andrea Calvo
- ALS Center, "Rita Levi Montalcini" Department of Neuroscience, University of Turin, Turin, Italy
| | - Angelina Cistaro
- Institute of Cognitive Sciences and Technologies, Consiglio Nazionale delle Ricerche (CNR), Rome, Italy; Positron Emission Tomography Center IRMET S.p.A, Euromedic Inc, Torino, Italy
| | - Massimo Filippi
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| |
Collapse
|
19
|
Brown R, Dissanayake KN, Skehel PA, Ribchester RR. Endomicroscopy and electromyography of neuromuscular junctions in situ. Ann Clin Transl Neurol 2014; 1:867-83. [PMID: 25540801 PMCID: PMC4265058 DOI: 10.1002/acn3.124] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 09/03/2014] [Indexed: 12/12/2022] Open
Abstract
Objective Electromyography (EMG) is used routinely to diagnose neuromuscular dysfunction in a wide range of peripheral neuropathies, myopathies, and neuromuscular degenerative diseases including motor neuron diseases such as amyotrophic lateral sclerosis (ALS). Definitive neurological diagnosis may also be indicated by the analysis of pathological neuromuscular innervation in motor-point biopsies. Our objective in this study was to preempt motor-point biopsy by combining live imaging with electrophysiological analysis of slow degeneration of neuromuscular junctions (NMJs) in vivo. Methods We combined conventional needle electromyography with fiber-optic confocal endomicroscopy (CEM), using an integrated hand-held, 1.5-mm-diameter probe. We utilized as a test bed, various axotomized muscles in the hind limbs of anaesthetized, double-homozygous thy1.2YFP16: WldS mice, which coexpress the Wallerian-degeneration Slow (WldS) protein and yellow fluorescent protein (YFP) in motor neurons. We also tested exogenous vital stains, including Alexa488-α-bungarotoxin; the styryl pyridinium dye 4-Di-2-Asp; and a GFP conjugate of botulinum toxin Type A heavy chain (GFP-HcBoNT/A). Results We show that an integrated EMG/CEM probe is effective in longitudinal evaluation of functional and morphological changes that take place over a 7-day period during axotomy-induced, slow neuromuscular synaptic degeneration. EMG amplitude declined in parallel with overt degeneration of motor nerve terminals. EMG/CEM was safe and effective when nerve terminals and motor endplates were selectively stained with vital dyes. Interpretation Our findings constitute proof-of-concept, based on live imaging in an animal model, that combining EMG/CEM may be useful as a minimally invasive precursor or alternative to motor-point biopsy in neurological diagnosis and for monitoring local administration of potential therapeutics.
Collapse
Affiliation(s)
- Rosalind Brown
- Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh Hugh Robson Building, George Square, Edinburgh, EH8 9XD, United Kingdom
| | - Kosala N Dissanayake
- Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh Hugh Robson Building, George Square, Edinburgh, EH8 9XD, United Kingdom
| | - Paul A Skehel
- Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh Hugh Robson Building, George Square, Edinburgh, EH8 9XD, United Kingdom
| | - Richard R Ribchester
- Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh Hugh Robson Building, George Square, Edinburgh, EH8 9XD, United Kingdom
| |
Collapse
|
20
|
|
21
|
Groisser BN, Copen WA, Singhal AB, Hirai KK, Schaechter JD. Corticospinal tract diffusion abnormalities early after stroke predict motor outcome. Neurorehabil Neural Repair 2014; 28:751-60. [PMID: 24519021 PMCID: PMC4128905 DOI: 10.1177/1545968314521896] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Prognosis of long-term motor outcome of acute stroke patients with severe motor impairment is difficult to determine. OBJECTIVE Our primary goal was to evaluate the prognostic value of corticospinal tract (CST) injury on motor outcome of the upper limb compared with motor impairment level and lesion volume. METHODS In all, 10 acute stroke patients with moderately severe to severe motor impairment of the upper limb underwent diffusion tensor imaging (DTI) and testing of upper limb strength and dexterity at acute, subacute, and chronic poststroke time points. A density-weighted CST atlas was constructed using DTI tractography data from normal participants. This CST atlas was applied, using a largely automated process, to DTI data from patients to quantify CST injury at each time point. Differences in axial diffusivity (AD), radial diffusivity (RD), and fractional anisotropy (FA) of the ipsilesional CST relative to the contralesional CST were measured. RESULTS Acute loss in CST AD correlated most strongly and significantly with subacute and chronic strength and dexterity and remained significant after adjusting for acute motor impairment or lesion volume. Subacute loss in CST FA correlated most strongly with chronic dexterity, whereas subacute behavioral measures of limb strength correlated most strongly with chronic strength measures. CONCLUSIONS Loss in acute CST AD and subacute CST FA are strong prognostic indicators of future motor functions of the upper limb for stroke patients with substantial initial motor impairment. DTI-derived measure of CST injury early after stroke may have utility in health care planning and in design of acute stroke clinical trials.
Collapse
Affiliation(s)
- Benjamin N Groisser
- MGH/HST Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - William A Copen
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Aneesh B Singhal
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Kelsi K Hirai
- MGH/HST Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Judith D Schaechter
- MGH/HST Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
22
|
Lessons of ALS imaging: Pitfalls and future directions - A critical review. NEUROIMAGE-CLINICAL 2014; 4:436-43. [PMID: 24624329 PMCID: PMC3950559 DOI: 10.1016/j.nicl.2014.02.011] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Revised: 02/23/2014] [Accepted: 02/23/2014] [Indexed: 12/19/2022]
Abstract
Background While neuroimaging in ALS has gained unprecedented momentum in recent years, little progress has been made in the development of viable diagnostic, prognostic and monitoring markers. Objectives To identify and discuss the common pitfalls in ALS imaging studies and to reflect on optimal study designs based on pioneering studies. Methods A “PubMed”-based literature search on ALS was performed based on neuroimaging-related keywords. Study limitations were systematically reviewed and classified so that stereotypical trends could be identified. Results Common shortcomings, such as relatively small sample sizes, statistically underpowered study designs, lack of disease controls, poorly characterised patient cohorts and a large number of conflicting studies, remain a significant challenge to the field. Imaging data of ALS continue to be interpreted at a group-level, as opposed to meaningful individual-patient inferences. Conclusions A systematic, critical review of ALS imaging has identified stereotypical shortcomings, the lessons of which should be considered in the design of future prospective MRI studies. At a time when large multicentre studies are underway a candid discussion of these factors is particularly timely. Stereotypical shortcomings can be identified in ALS neuroimaging studies. A systematic discussion of ALS study limitations is particularly timely. Individual patient data meta-analyses and multicentre studies are urgently required. The gaps identified in ALS imaging indicate exciting research opportunities.
Collapse
Key Words
- AD, axial diffusivity
- Amyotrophic lateral sclerosis
- Biomarker
- C9orf72, chromosome 9 open reading frame 72
- DTI, diffusion tensor imaging
- FA, fractional anisotropy
- MD, mean diffusivity
- MEG, magnetoencephalography
- MRI
- MRS, magnetic resonance spectroscopy
- MUNE, motor unit number estimation
- PET
- PET, positron emission tomography
- PNS, peripheral nervous system
- RD, radial diffusivity
- ROI, region of interest
- SPECT, single photon emission computed tomography
- Spectroscopy
- TMS, transcranial magnetic stimulation
- VBM, voxel-based morphometry
Collapse
|
23
|
Rajagopalan V, Pioro EP. Distinct patterns of cortical atrophy in ALS patients with or without dementia: an MRI VBM study. Amyotroph Lateral Scler Frontotemporal Degener 2014; 15:216-25. [PMID: 24555884 DOI: 10.3109/21678421.2014.880179] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Voxel based morphometry (VBM) allows objective and automated detection of structural changes in brains of patients with amyotrophic lateral sclerosis (ALS). We investigated whether VBM could identify cortical atrophy from T1-weighted images obtained during routine 1.5T studies of ALS patients with various clinically defined phenotypes. For this purpose T1-weighted brain MRI was obtained at 1.5T during routine clinical study in neurologic disease controls (n = 15) and ALS patients (n = 88) categorized into four subgroups based on their clinical phenotypes: predominant upper motor neuron (UMN) dysfunction with or without corticospinal tract (CST) hyperintensity (ALS-CST+/-), combined UMN and prominent lower motor neuron (LMN) dysfunction (classic ALS), and frontotemporal dementia (ALS-FTD). VBM analysis of gray matter (GM) was carried out using FSL. Results demonstrated that clinically obtained brain MRI at 1.5T revealed significantly reduced GM volume in brains of only ALS-FTD patients and not of those with predominant UMN dysfunction or classic ALS, compared to neurologic disease controls. In conclusion, GM volume loss in motor and extramotor regions of only ALS patients with FTD and not of ALS patients without FTD suggests distinct sites of predominant pathology and possibly of disease onset. Brain volumetric measures supplemented by histopathological correlations and other neuroimaging techniques, such as diffusion tensor imaging, may provide insight into ALS pathophysiology.
Collapse
Affiliation(s)
- Venkateswaran Rajagopalan
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic , Cleveland, Ohio , USA
| | | |
Collapse
|