Amyotrophic lateral sclerosis – The tools of the trait

Clinical recognition and management of amyotrophic lateral sclerosis: the nurse's role

Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease, causes a progressive wasting and loss of the upper and lower motor neurons that facilitate the movement of body parts. At onset, ALS patients may show symptoms such as muscle weakness, atrophy, hyperreflexia, or bulbar symptoms such as dysphagia or dysarthria. Deterioration progresses rapidly, and the later stages of ALS are characterized by severely limited mobility and respiratory failure, which is the primary cause of death. There is no specific diagnostic test for ALS, and there are a number of other conditions that may resemble ALS, making a diagnosis difficult. The variability of the initial presentation combined with the broad differential diagnosis may result in significant delays in diagnosis or, in some cases, misdiagnosis, which in turn have a negative impact on patient outcomes. There is no cure for ALS; however, many of the symptoms are treatable, and the physical and psychological symptoms are best managed through the efforts of a coordinated, multidisciplinary team. Nurses play a critical role in the clinical management of ALS and may be involved in coordinating the activities of the team, facilitating treatment, and helping patients and caregivers in making informed treatment and end-of-life decisions. Drug therapy for ALS is currently limited to riluzole; however, patients may be treated with a number of nonpharmacologic methods on the basis of their symptoms. A number of other treatment modalities, such as stem-cell-based therapy or gene therapy, and an array of neuroprotective clinical trials are currently under development for the treatment of ALS. Nurses may also have a key role in these various ALS studies.

Autoimmunity in amyotrophic lateral sclerosis: past and present

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease affecting particularly motor neurons for which no cure or effective treatment is available. Although the cause of ALS remains unknown, accumulative evidence suggests an autoimmune mechanism of pathogenesis. In this paper, we will summarize the current research related to autoimmunity in the sporadic form of ALS and discuss the potential underlying pathogenic mechanisms and perspectives. Presented data supports the view that humoral immune responses against motor nerve terminals can initiate a series of physiological changes leading to alteration of calcium homeostasis. In turn, loss of calcium homeostasis may induce neuronal death through apoptotic signaling pathways. Additional approaches identifying specific molecular features of this hypothesis are required, which will hopefully allow us to develop techniques of early diagnosis and effective therapies.

Distribution, differentiation, and survival of intravenously administered neural stem cells in a rat model of amyotrophic lateral sclerosis

The transplantation of neural stem cells (NSCs) is a challenging therapeutic strategy for the treatment of neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS). To provide insight into the potential of the intravenous delivery of NSCs, we evaluated the delivery of NSCs marked with green fluorescent protein to the central nervous system (CNS) via intravenous tail vein injections in an ALS model. The injected cell fates were followed 1, 3, and 7 days after transplantation. The highest efficiency of cell delivery to the CNS was found in symptomatic ALS (up to 13%), moderate in presymptomatic ALS (up to 6%), and the lowest in wild-type animals (up to 0.3%). NSCs injected into ALS animals preferentially colonized the motor cortex, hippocampus, and spinal cord, and their differentiation was characterized by a decrease of nestin expression and the appearance of MAP2-, GFAP-, O4-, and CD68-positive cells. Tumor necrosis factor (TNF) administration increased the CNS delivery of transplanted cells in wild-type and presymptomatic, but not ALS symptomatic animals. Moreover, a TNF-related increase in NSC differentiation and survival was detected. Apoptosis was detected as the main cause of the loss of transplanted cells and it was influenced by TNF. Although 3 days after TNF treatment cell death was accelerated, TNF slowed down apoptosis after 7 days. This study provides elementary facts about the process occurring after NSCs leave the blood stream and enter the nervous tissue affected by inflammation/degeneration, which should help facilitate the planning of future bench-to-bedside translational projects.

Neural stem cells: mechanisms of fate specification and nuclear reprogramming in regenerative medicine

Recently, intense interest in the potential use of neural stem cells (NSC) in the clinical therapy of brain disease and injury has resulted in rapid progress in research on the properties of NSC, their innate and directed differentiation potential and the induced reprogramming of differentiated somatic cells to revert to a pluripotent NSC-like state. The aim of this review is to give an overview of our current operational definitions of the NSC lineage, the growing understanding of extrinsic and intrinsic mechanisms, including heritable but reversible epigenetic chromatin modifications that regulate the maintenance and differentiation of NSC in vivo, and to emphasize ground-breaking efforts of cellular reprogramming with the view to generating patient-specific stem cells for cell replacement therapy. This is set against a summary of current practical procedures for the isolation, research and application of NSC, and of the state of the art in NSC-based regenerative medicine of the nervous system. Both provide the backdrop for the translation of recent findings into innovative clinical applications, with the hope of increasing the safety, efficiency and ethical acceptability of NSC-based therapies in the near future.

The involvement of DNA-damage and -repair defects in neurological dysfunction

A genetic link between defects in DNA repair and neurological abnormalities has been well established through studies of inherited disorders such as ataxia telangiectasia and xeroderma pigmentosum. In this review, we present a comprehensive summary of the major types of DNA damage, the molecular pathways that function in their repair, and the connection between defective DNA-repair responses and specific neurological disease. Particular attention is given to describing the nature of the repair defect and its relationship to the manifestation of the associated neurological dysfunction. Finally, the review touches upon the role of oxidative stress, a leading precursor to DNA damage, in the development of certain neurodegenerative pathologies, such as Alzheimer's and Parkinson's.