The corticospinal tract profile in amyotrophic lateral sclerosis

This work evaluates the potential in diagnostic application of a new advanced neuroimaging method, which delineates the profile of tissue properties along the corticospinal tract (CST) in amyotrophic lateral sclerosis (ALS), by means of diffusion tensor imaging (DTI). Twenty‐four ALS patients and twenty‐four demographically matched healthy subjects were enrolled in this study. The Automated Fiber Quantification (AFQ), a tool for the automatic reconstruction of white matter tract profiles, based on a deterministic tractography algorithm to automatically identify the CST and quantify its diffusion properties, was used. At a group level, the highest non‐overlapping DTI‐related differences were detected in the cerebral peduncle, posterior limb of the internal capsule, and primary motor cortex. Fractional anisotropy (FA) decrease and mean diffusivity (MD) and radial diffusivity (RD) increases were detected when comparing ALS patients to controls. The machine learning approach used to assess the clinical utility of this DTI tool revealed that, by combining all DTI metrics measured along tract between the cerebral peduncle and the corona radiata, a mean 5‐fold cross validation accuracy of 80% was reached in discriminating ALS from controls. Our study provides a useful new neuroimaging tool to characterize ALS‐related neurodegenerative processes by means of CST profile. We demonstrated that specific microstructural changes in the upper part of the brainstem might be considered as a valid biomarker. With further validations this method has the potential to be considered a promising step toward the diagnostic utility of DTI measures in ALS. Hum Brain Mapp 38:727–739, 2017. © 2016 Wiley Periodicals, Inc.     

Alterations of the blood‐spinal cord barrier in sporadic amyotrophic lateral sclerosis

The blood‐spinal cord barrier (BSCB) of the spinal cord capillary consists of non‐fenestrated endothelial cells with tight junctions, basal laminae, pericytes and astrocyte feet processes, referred to as a “neurovascular unit.” The primary function of the BSCB is the maintenance and control of homeostasis of the spinal cord parenchyma by the selective transport of molecules and cells from the systemic compartment. Dysfunction of the BSCB shows important function in the etiology or progression of several pathological conditions of the spinal cord, including amyotrophic lateral sclerosis (ALS). However, the role of BSCB in the pathogenesis of ALS is still unclear. Here the changes of BSCB in sporadic ALS patients were studied by electron microscopy to determine whether the BSCB is disrupted and involved in the pathogenesis of motor neuron degeneration. A total of 358 and 366 cross‐sectioned capillaries were quantitatively examined in controls and ALS patients, respectively. The frequency of degenerated endothelia and pericytes, vacuolar changes of the cytoplasm in the endothelia and pericytes, and the replication of basement membranes was significantly higher in ALS patients than in the controls (P = 0.0175). The areas of the capillaries with diameters of ≤ 5 µm in the ALS patients were significantly smaller than those in the controls (P = 0.0124). The frequency of collagen fiber content of more than a moderate degree around the perivascular space was significantly higher in the ALS patients compared to the controls (P = 0.048), although there was no significant difference in the mild degree of accumulation of collagen fibers. Thus, the BSCB may be disrupted in sporadic ALS patients due to increased permeability and reduced microcirculation, leading to motor neuron degeneration and to the progression of the disease.     

以胸髓前角先受累的肌萎缩侧索硬化的临床特点

目的探讨胸髓前角先受累的肌萎缩侧索硬化(ALS)患者的临床特征。方法回顾性分析3例以胸髓前角先受累的ALS患者的临床资料。结果3例患者均为男性,发病年龄分别为52岁、66岁、62岁;均以呼吸困难为首发表现,有明显的肋间肌和腹直肌萎缩,而肢体肌无力及肌萎缩的出现相对较轻、较迟;肌电图显示上肢及椎旁肌的神经源性损害。结论以胸髓前角先受累的ALS患者以男性多见,起病年龄晚于ALS的平均发病年龄,呼吸困难明显,呼吸肌萎缩早于肢体肌无力及肌萎缩,肌电图检查可以确诊。     

Combined MR spectroscopic imaging and diffusion tensor MRI visualizes corticospinal tract degeneration in amyotrophic lateral sclerosis

Abstract. Motor neuron damage and cortical spinal tract (CST) degeneration are pathological features of amyotrophic lateral sclerosis (ALS). We combined whole-brain diffusion tensor imaging (DTI) and three-dimensional magnetic resonance spectroscopic imaging (MRSI) to study the CST at different locations. Eight ALS patients were compared with normal controls. Fractional anisotropy (FA) and mean diffusivity (MD), and the ratio of N-acetyl-aspartate (NAA) to creatine (Cr) were measured at various locations in the CST, including the subcortical white matter (SWM), centrum semiovale (CS), periventricular white matter (PV), posterior limb of the internal capsule (PIC) and cerebral peduncle (CP). Patients showed significantly lower FA than controls in the CST, including the SWM, CS, PV and PIC. Although there was a trend towards elevated MD in ALS patients, this did not reach statistical significance. NAA/Cr ratios were also decreased in ALS patients compared with normal controls, with significant differences in the SWM and PV but not in PIC. Combined whole-brain DTI and MRSI can detect axonal degeneration in ALS. Measurements of FA obtained in the SWM, CS, PV and PIC, and NAA/Cr ratios in the SWM and PV yield the most robust results.     

Collagen abnormalities in the spinal cord from patients with amyotrophic lateral sclerosis

During the last 10 years, we have demonstrated morphological and biochemical abnormalities of skin extracellular matrices in amyotrophic lateral sclerosis (ALS). However, currently little is known concerning collagen of the spinal cord in ALS. We measured the amount of collagen and characterized collagen at light and electron microscopic levels in posterior funiculus, posterior half of lateral funiculus and anterior horn of cervical enlargement of the spinal cord obtained from ten patients with ALS, 11 patients with other neurologic diseases (control group A), and ten patients without neurologic ones (control group B). In posterior half of lateral funiculus and anterior horn, (1) by light microscopy, there was no significant difference in vessel wall area between ALS patients and control groups A and B; (2) ultrastructurally, collagen bundles were more fragmented and widely separated, and the fibrils were randomly oriented in the perivascular space of capillaries in ALS patients, which were not observed in any areas of control groups or in posterior funiculus of ALS patients; and (3) the collagen contents in ALS were significantly lower (P<0.001 and P<0.001, respectively) than those in control groups A and B. Fragmented and widely separated collagen bundles in the interstitial tissue surrounding capillaries and markedly decreased amount of collagen in posterior half of lateral funiculus and in anterior horn of ALS could be related to the degeneration of the upper and lower motor neurons in the spinal cord in ALS, that is, selective neuronal vulnerability in ALS.     

Morphometric and topographical studies of small neurons in sporadic amyotrophic lateral sclerosis spinal gray matter

Little attention has been paid to the degeneration of small neurons in ALS spinal gray matter. The purpose of the present paper was to undertake morphometric and quantitative analysis of the spinal gray matter of 15 ALS patients and compare findings to those of five controls. A significant reduction of small neurons in the anteromedial and intermediate parts of the gray matter were detected in ALS spinal cords with diffuse myelin pallor in the ventral aspects of the anterolateral columns outside the corticospinal tracts, and the number of small neurons in these areas was decreased significantly depending on the intensity of the myelin pallor. There were no significant alterations in the number of small neurons in the corresponding areas of ALS spinal cords without diffuse myelin pallor or in those of controls. In the posterior parts of the gray matter, there were no significant differences in the number of small neurons among ALS patients and controls. These findings strongly suggest that diffuse myelin pallor in the ventral aspects of anterolateral columns in ALS spinal cords is derived from the degeneration of small neurons in the anteromedial and intermediate parts of the gray matter.     

Choline acetyltransferase and substance P-like immuno-reactivity in the human spinal cord: changes in amyotrophic lateral sclerosis

The topographic location of the enzyme choline acetyltransferase (ChAT) has recently been determined within the human spinal cord². ChAT, which is regarded as a specific marker of cholinergic structures in nervous tissue, showed an area of high activity in the ventrolateral part of the ventral horn, probably related to motor neurons. In addition, an area of high ChAT activity was found in the apical part of the dorsal horn. As amyotrophic lateral sclerosis (ALS) is characterized by progressive degeneration of the cortico-spinal tracts and the lower motor neurons, we considered it of value to investigate the involvement of spinal cholinergic structures in this disorder. Substance P is regarded as the transmitter of incoming pain signals to the dorsal horn of the spinal cord, a subject recently reviewed by Marx¹⁰. As disturbed sensation of pain is not a symptom of ALS, there seemed reason to correlate the spinal concentration of this peptide with the activities of ChAT in ALS.     

Enhanced Fos expression in rat lumbar spinal cord cultured with cerebrospinal fluid from patients with amyotrophic lateral sclerosis

Abstract

School, Okayama, Japan The etiology of amyotrophic lateral sclerosis (ALS) remains unknown although an existence of neurotoxic substances in cerebrospinal fluid (CSF) from ALS patients have been postulated. In order to investigate a possible effect of CSF from ALS patients on cellular signaling in spinal neurons, we compared Fos-like immunoreactivity (Fos-LI) in organotypic cultures of rat lumbar spinal cord after addition of CSF from ALS patients or another neurologic disease. Fos-LI was normally present predominantly in dorsal horn neurons, whereas only a few ventral horn neurons were positive for Fos-LI. The number of Fos-LI positive neurons significantly increased in dorsal horn with addition of CSF from ALS patients as well as glutamate at 100 μM. However, the increase was not observed with addition of CSF from other neurologic diseases. The increase in Fos-LI positive neurons in dorsal horn was reversed by a further supplement of MK801, an N-methyl-D-aspartate (NMDA) receptor antagonist, but not of CNQX, an a-amino-3-hydroxy-5-methyl-4- isoxazole propionic acid (AMPA)/kainate antagonist. These results indicate that there may be substances in CSF from ALS patients that stimulate Fos expression in certain populations of spinal neurons via the NMDA receptors. [Neurol Res 1999; 21: 309-312]     

Biogenic amines and metabolites in spinal cord of patients with Parkinson's disease and amyotrophic lateral sclerosis

Summary In four human controls, four cases of Parkinson's disease and three cases of amyotrophic lateral sclerosis analysis of dopamine, noradrenaline, serotonin and the metabolites 3,4-dihydroxyphenylacetic acid, homovanillic acid and 5-hydroxyindoleacetic acid was performed in various segments of postmortem spinal cord. In controls the concentrations of dopamine are about 1/3 to 1/4 that of noradrenaline; the significantly highest content of noradrenaline was found in the lumbar, and dopamine in thoracic, lumbar and sacral segments of the spinal cord. Intersegmental distribution of monoamines was only present in spinal cord of controls, while in the spinal cord of parkinsonian patients such a difference was not found.Otherwise, biogenic amine and metabolite concentrations in spinal cord segments of parkinsonian patients did not differ significantly from those in the control subjects. However, it cannot be excluded that these segments are sensitive to drugs including neuroleptics and combined L-DOPA treatment.In subjects with amyotrophic lateral sclerosis significantly lower concentrations of noradrenaline in the cervical and thoracic, and of dopamine and homovanillic acid in the thoracic and lumbar segments were found in comparison with controls. The concentrations of serotonin and 5-hydroxyindoleacetic acid in the thoracic segments of amyotrophic lateral sclerosis were significantly lower than that of controls. Differences in the inter-segmental distribution of noradrenaline in lumbar, lumbar-sacral, and serotonin in lumbar segments of spinal cord were found in this group.     

The anterolateral funiculus in the spinal cord in amyotrophic lateral sclerosis

We carried out a morphometric study on the myelinated fibers in the anterolateral funiculus (ALF) and lateral corticospinal tract (LCS) in the cervical segment of the spinal cord of 13 patients with classic amyotrophic lateral sclerosis (ALS), 6 of whom had been on a respirator: 5 age-matched subjects were used as controls. The results obtained revealed that: (1) the fiber-size distributions of the myelinated fibers in the ALF and LCS of the control subjects had peaks at 2 m; (2) there were marked and significant losses of large myelinated fibers in the ALF and LCS of ALS patients; (3) the patients who required respirator support showed more severe degeneration in the ALF than those who required none; and (4) the degree of myelinated fiber loss in the LCS did not correlate with either the illness duration or the history of respirator use.     

Relationship between cervical cord 1H‐magnetic resonance spectroscopy and clinoco‐electromyographic profile in amyotrophic lateral sclerosis

Introduction: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the loss of motor neurons, leading to limb paralysis and respiratory failure. Methods: C1–C3 cord ¹H‐magnetic resonance spectroscopy (¹H‐MRS) was performed in 19 patients with ALS and 20 controls. N‐acetylaspartate (NAA), choline‐containing compounds, creatine plus phosphocreatine (Cr), and myo‐Inositol (m‐Ins) were measured. ALS Functional Rating Scale‐Revised (ALSFRS) and forced vital capacity (FVC) were assessed. The rates of decline were calculated at 6 months before and after ¹H‐MRS. Results: NAA/Cr and NAA/m‐Ins were decreased significantly, and m‐Ins/Cr was increased significantly in ALS patients compared with controls. NAA/Cr and NAA/m‐Ins were correlated with ALSFRS and FVC and inversely linked to the decline rates. NAA/Cr, NAA/m‐Ins, and m‐Ins/Cr were altered markedly in 9 patients with denervation and neurogenic changes in both C2 paraspinal and upper limb muscles. Conclusions: These metabolite ratios were associated with disease progression and ongoing denervation in neck and hand muscles. C1–C3 cord ¹H‐MRS might reflect anterior horn cell damage causing neck/arm weakness and respiratory dysfunction in ALS patients. Muscle Nerve, 2013     

Membranous cytoplasmic bodies in the anterior horn neurons in two patients with amyotrophic lateral sclerosis

We observed abundant membranous cytoplasmic bodies in several remaining anterior horn neurons in two patients with sporadic amyotrophic lateral sclerosis (ALS). These bodies were rare in the neurons of the frontal cortex and of the rectum examined in one case. The link between membranous cytoplasmic bodies and ALS is vague; however, pathogenesis of ALS is unknown and there are few reports on the lysosomal system in ALS. Therefore, further study is needed in order to evaluate abnormalities in the lysosomal system to clarify the degenerative processes in ALS.     

Coexistence of amyotrophic lateral sclerosis with neuro‐Behçet's disease presenting as a longitudinally extensive spinal cord lesion: clinicopathologic features of an autopsied patient

We report the clinical and autopsy features of a 65‐year‐old Japanese man who clinically exhibited overlap of both neuro‐Behçet's disease (NBD) and amyotrophic lateral sclerosis (ALS). The patient had a HLA‐B51 serotype, a recent history of uveitis and had suffered paraparesis, sensory and autonomic disturbance, frontal signs and tremor. A brain and spine MRI study revealed a longitudinally extensive thoracic cord (Th) lesion, but no apparent intracranial abnormalities. The lesion extended ventrally from Th4 to Th9, exhibiting low intensity on T1‐weighted images, high intensity on T2‐weighted and fluid‐attenuated inversion recovery images and gadolinium enhancement. The patient's upper and lower motor neuron signs and sensory disturbance worsened and he died 16 months after admission. At autopsy, the spinal cord and brain exhibited characteristic histopathological features of both NBD and ALS, including chronic destruction of the ventral thoracic white and gray matter, perivascular lymphocytic infiltration, binucleated neurons, lower and upper motor neuron degeneration, Bunina bodies and skein‐like inclusions. Although incidental coexistence of these rare disorders could occur in an individual, this case raises the possibility of a pathomechanistic association between NBD and ALS.     

Immunohistochemical characterization of the inflammatory infiltrate in amyotrophic lateral sclerosis

In order to test the hypothesis that the immune system plays a role in the pathogenesis of amyotrophic lateral sclerosis (ALS), the cellular composition of the spinal cord inflammatory infiltrate was analysed in eight cases of sporadic ALS by a panel of monoclonal antibodies. The majority of the many diffusely scattered lymphocytes seen in the anterior and lateral corticospinal tracts and anterior horns belonged to the suppressor/cytotoxicity T-cell subset and were admixed with variable numbers of macrophages. Helper-inducer T-cells were rare and B-cells were conspicuously absent. Compared to controls, ALS specimens exhibited an increase in major histocompatibility complex (MHC) products or human leucocyte antigens (HLA) in the corticospinal tracts and anterior horns. HLA-ABC antigens were expressed in the honeycomb pattern of the glial matrix of the spinal cord, and HLA-DR antigens were strongly expressed by large dendritic cells. In addition, macrophages and endothelial cells were labelled by HLA-DR. These findings suggest that an autoimmune process or infectious agent may play a role in ALS.     

Primary lateral sclerosis: Upper‐motor‐predominant amyotrophic lateral sclerosis with frontotemporal lobar degeneration – immunohistochemical and biochemical analyses of TDP‐43

Primary lateral sclerosis (PLS) is clinically defined as a disorder selectively affecting the upper motor neuron (UMN) system. However, recently it has also been considered that PLS is heterogeneous in its clinical presentation. To elucidate the association of PLS, or disorders mimicking PLS, with 43‐kDa TAR DNA‐binding protein (TDP‐43) abnormality, we examined two adult patients with motor neuron disease, which clinically was limited almost entirely to the UMN system, and was followed by progressive frontotemporal atrophy. In the present study, the distribution and severity, and biochemical profile of phosphorylated TDP‐43 (pTDP‐43) in the brains and spinal cords were examined immunohistochemically and biochemically. Pathologically, in both cases, frontotemporal lobar degeneration with ubiquitin inclusions (FTLD‐U) was evident, with the most severe degeneration in the motor cortex. An important feature in both cases was the presence of Bunina bodies and/or ubiquitin inclusions, albeit very rarely, in the well preserved lower motor neurons. The amygdala and neostriatum were also affected. pTDP‐43 immunohistochemistry revealed the presence of many positively stained neuronal cytoplamic inclusions (NCIs) and dystrophic neurites/neuropil threads in the affected frontotemporal cortex and subcortical gray matter. By contrast, such pTDP‐43 lesions, including NCIs, were observed in only a few lower motor neurons. pTDP‐43 immunoblotting revealed that fragments of ～25‐kDa were present in the cortices, but not in the spinal cord in both cases. Genetically, neither of the patients had any mutation in the TDP‐43 gene. In conclusion, we consider that although PLS may be a clinically significant disease entity, at autopsy, the majority of such clinical cases would present as upper‐motor‐predominant amyotrophic lateral sclerosis with FTLD‐TDP.     

Increased expression of TDP‐43 in the skin of amyotrophic lateral sclerosis

Suzuki M, Mikami H, Watanabe T, Yamano T, Yamazaki T, Nomura M, Yasui K, Ishikawa H, Ono S. Increased expression of TDP‐43 in the skin of amyotrophic lateral sclerosis. Acta Neurol Scand: 2010: 122: 367–372. © 2010 The Authors Journal compilation © 2010 Blackwell Munksgaard. Objectives – Transactivation‐responsive DNA‐binding protein‐43 (TDP‐43) was indentified as a major component of the ubiquitin‐positive inclusions in sporadic amyotrophic lateral sclerosis (ALS). However, there has been no study of TDP‐43 in ALS skin. The present study investigates TDP‐43 in ALS skin. Materials and methods – We made a quantitative immunohistochemical study of the expression of TDP‐43 in the skin from 15 patients with ALS and 15 control subjects. Results – The proportion of TDP‐43‐positive (TDP‐43+) cells in the epidermis in ALS patients was significantly higher (P < 0.001) than in controls. There was a significant positive relationship (r = 0.62, P < 0.02) between the proportion and duration of illness in ALS patients. The optical density of TDP‐43+ cells in the epidermis in ALS patients is markedly stronger (P < 0.001) than in controls. There was a significant positive relation (r = 0.72, P < 0.01) between the immunoreactivity and duration of illness in ALS patients. Conclusions – These data suggest that changes of TDP‐43 in ALS skin are likely to be related to the disease process and that metabolic alterations of TDP‐43 may take place in the skin of patients with ALS.     

T cells in amyotrophic lateral sclerosis

The inflammatory process in ALS involves infiltration of T cells and activation of antigen presenting cells co-localizing with motor neuron damage in the brain and spinal cord. The role of T cells in the pathogenic process is not settled. T cells may damage motor neurons by cell-cell contact or cytokine secretion, or contribute indirectly to motor neuron damage through activation of microglia and macrophages. Alternatively, T cell infiltration may be an epiphenomenon related to clearance of dead motor neurons. Lessons from animal models of neuroinflammation and neurodegeneration have shown that T cell responses can be neuroprotective or even enhance neurogenesis. Therefore, it is possible that T cells can be induced to slow motor neuron destruction and facilitate repair in ALS. The T cell modulating drug glatiramer acetate has shown promising results in animal models, and is being currently investigated in a phase II trial in ALS. This paper reviews the evidence for T cells as pathogenic players and therapeutic targets in ALS.     

Brain and spinal cord affected by amyotrophic lateral sclerosis induce differential growth factors expression in rat mesenchymal and neural stem cells

C. Nicaise, D. Mitrecic and R. Pochet (2011) Neuropathology and Applied Neurobiology 37, 179–188
Brain and spinal cord affected by amyotrophic lateral sclerosis induce differential growth factors expression in rat mesenchymal and neural stem cells Stem cell research raises hopes for incurable neurodegenerative diseases. In amyotrophic lateral sclerosis (ALS), affecting the motoneurones of the central nervous system (CNS), stem cell‐based therapy aims to replace dying host motoneurones by transplantation of cells in disease‐affected regions. Moreover, transplanted stem cells can serve as a source of trophic factors providing neuroprotection, slowing down neuronal degeneration and disease progression. Aim: To determine the profile of seven trophic factors expressed by mesenchymal stem cells (MSC) and neural stem cells (NSC) upon stimulation with CNS protein extracts from SOD1‐linked ALS rat model. Methods: Culture of rat MSC, NSC and fibroblasts were incubated with brain and spinal cord extracts from SOD1(G93A) transgenic rats and mRNA expression of seven growth factors was measured by quantitative PCR. Results: MSC, NSC and fibroblasts exhibited different expression patterns. Nerve growth factor and brain‐derived neurotropic factor were significantly upregulated in both NSC and MSC cultures upon stimulation with SOD1(G93A) CNS extracts. Fibroblast growth factor 2, insulin‐like growth factor and glial‐derived neurotropic factor were upregulated in NSC, while the same factors were downregulated in MSC. Vascular endothelial growth factor A upregulation was restricted to MSC and fibroblasts. Surprisingly, SOD1(G93A) spinal cord, but not the brain extract, upregulated brain‐derived neurotropic factor in MSC and glial‐derived neurotropic factor in NSC. Conclusions: These results suggest that inherent characteristics of different stem cell populations define their healing potential and raise the concept of ALS environment in stem cell transplantation.