What's in a name? Amyotrophic lateral sclerosis, motor neuron disease, and allelic heterogeneity

Vitis vinifera: An Alternative for the Prevention of Neurodegenerative Diseases

To present a systematic review of published studies in databases such as PUBMED, REDALYC, SCIELO, DIALNET, SCOPUS, EBSCO and CONRICYT related to the role-played by the components present in the vegetable oil of grape seed (Vitis vinífera) and the prevention or delay in the onset or progression of neurodegenerative diseases. The analysis of the research revealed that neurodegenerative diseases causes alterations in consciousness or in the nervous system leading to severe damage in neuronal cells, these pathologies are considered gradual and progressive. Various syndromes manifest the degenerative diseases of the nervous system; in some of them the predominant symptom is the progressive dementia. Among the components of the diet that in numerous epidemiological studies have shown an inverse association are vitamins, minerals, carotenoids, polyunsaturated fatty acids and polyphenols, the latter being the ones addressed in this document. There is an important evidence that a nutritional support based on polyunsaturated fatty acids and antioxidants can be applied to subjects with a history of neurodegenerative conditions in order to act as neuroprotectors. This requires the determination of the nutritional benefits of these nutrients or of nutraceuticals for the health of this group of patients.

A robust and novel electrical impedance metric of pulmonary function in ALS patients

OBJECTIVE

Pulmonary function tests (PFTs) are important for assessing respiratory function in amyotrophic lateral sclerosis (ALS) patients. However, weakness of oral and glottal closure, due to concomitant bulbar dysfunction, may result in unreliable PFT values stemming from leakage of air around the breathing tube and through the glottis. In this study, we assessed whether standard thoracic electrical impedance tomography (EIT) could serve as a surrogate measure for PFTs.

APPROACH

Thoracic EIT was performed simultaneously with standard PFTs on seven ALS patients without clinical bulbar weakness (six men and one woman, mean age of 63 years) and ten healthy volunteers (seven men and three women, mean age of 57 years). A raw impedance metric along with more standard EIT measures were computed and correlated with the normalized forced vital capacity (FVC). Additionally, test/re-test metrics and EIT images were analyzed.

MAIN RESULTS

The impedance metric was found to be robust and sensitive to lung activity. We also identified qualitative EIT differences between healthy volunteers and ALS patients, with the ALS images showing greater heterogeneity. Significant correlations with FVC were found for both impedance and EIT metrics in ALS patients (r² = 0.89) and for the impedance metric only in healthy volunteers (r² = 0.49).

SIGNIFICANCE

This suggests that EIT, using our novel impedance metric, has the potential to serve as an alternative technology to standard PFTs for assessing pulmonary function in patients with ALS, offering new metrics of disease status for those with bulbar weakness.

Ethical issues in states of impaired communication with intact consciousness and language

Acute and chronic peripheral and/or central disorders of the voluntary motor system can produce profound paresis or paralysis, at times with ophthalmoplegia, while preserving consciousness and language function. Although at times appearing to be unconscious, these patients are awake and alert but unable to communicate, manipulate their environment, or participate in medical decision-making. Clinicians caring for these patients are ethically tasked with recognizing this clinical reality, enacting measures to facilitate communication, and abiding by ethical and legal principles that support autonomous patient-centered decision-making. This chapter reviews the various disorders that may cause this state while using three exemplary disorders - locked-in syndrome, caused by an anterior pontine lesion; high cervical spinal cord lesion; and amyotrophic lateral sclerosis - to discuss the management of these patients.

Motor neuron disease and frontotemporal lobar degeneration: a tale of two disorders linked to TDP-43

Motor neuron disease (MND) is a neurodegenerative condition long thought to be associated only with motor weakness. Recent work now shows that cognitive difficulties are present in up to half of the patients with this disorder. About 5-10% of patients with MND have a frank dementia that resembles frontotemporal lobar degeneration (FTLD). Imaging studies show quantitative abnormalities that resemble FTLD. Moreover, biochemical studies of ubiquinated histopathologic abnormalities in MND and FTLD reveal identical inclusions of TDP-43. These findings underline a fundamental link between MND and FTLD. This paper reviews this body of work.

Intake of polyunsaturated fatty acids and vitamin E reduces the risk of developing amyotrophic lateral sclerosis

BACKGROUND

To assess whether the premorbid dietary intake of fatty acids, cholesterol, glutamate or antioxidants was associated with the risk of developing amyotrophic lateral sclerosis (ALS).

METHODS

Patients referred to our clinic during 2001-2002, who had definite, probable or possible ALS according to El Escorial criteria, without a familial history of ALS, were asked to participate in a case-control study (132 patients and 220 healthy controls). A food-frequency questionnaire was used to assess dietary intake for the nutrients of interest. Multivariate logistic regression analysis was performed with adjustment for confounding factors (sex, age, level of education, energy intake, body mass index and smoking).

RESULTS

A high intake of polyunsaturated fatty acid (PUFA) and vitamin E was significantly associated with a reduced risk of developing ALS (PUFA: odds ratio (OR) = 0.4, 95% confidence interval (CI) = 0.2 to 0.7, p = 0.001; vitamin E: OR = 0.4, 95% CI = 0.2 to 0.7, p = 0.001). PUFA and vitamin E appeared to act synergistically, because in a combined analysis the trend OR for vitamin E was further reduced from 0.67 to 0.37 (p = 0.02), and that for PUFA from 0.60 to 0.26 (p = 0.005), with a significant interaction term (p = 0.03). The intake of flavonols, lycopene, vitamin C, vitamin B2, glutamate, calcium or phytoestrogens was not associated with the risk of developing ALS.

CONCLUSION

A high intake of PUFAs and vitamin E is associated with a 50-60% decreased risk of developing ALS, and these nutrients appear to act synergistically.

Sexual differences in onset of disease and response to exercise in a transgenic model of ALS

Transgenic mice that overexpress the mutant human SOD1 gene (hSOD1) serve as an animal model for amyotrophic lateral sclerosis (ALS). Age and sex are recognized as risk factors for ALS, but physical activity remains controversial. Therefore, we investigated the effect of exercise on the phenotype of male and female hSOD1 mice. Onset of disease, progression of disease and survival were measured in low-copy and high-copy hSOD1 mice that were randomized to an exercise or sedentary group. We found that onset of disease was different for the two sexes: significantly earlier in male than in female hSOD1 mice. Exercise delayed the onset of disease in female but not in male hSOD1 mice. Also, exercise delayed the total survival time in female high-copy hSOD1 mice. Muscle morphometry and motor neuron counts were similar in all experimental groups at the end of training. Sedentary female hSOD1 mice showed more frequently irregular estrous cycles suggesting a higher estrogen exposure in exercising female mice. These results suggest a possible neuroprotective effect of female sex hormones and support the view that ALS patients should not avoid regular exercise.

Recent advances in amyotrophic lateral sclerosis research

Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease in adults. Despite several genetic breakthroughs, the actual cause and mechanism of neurodegeneration in ALS remains a mystery. Nevertheless, recent scientific and clinical advances have led to the development of new therapeutic strategies for this progressive, fatal disorder. We review the progress of the most recent clinical trials in ALS, taking into account some of the hurdles encountered by these studies. We also discuss the potential role of retroviral infection as a cause or contributor to ALS, which is one of the most recent hypotheses for the pathogenesis of the disease. The genetic background of ALS is summarized and special attention is given to the newly identified ALS gene ALS2, and to those that are currently being investigated. The last part of this review is dedicated to the mutation in superoxide dismutase-1 (SOD1). The hypothesized deleterious mechanisms of mutant SOD1 are discussed, as well as the possibilities that the mutant protein activates the apoptotic cell death process and that these molecular alterations can be exploited to devise experimental neuroprotective therapies.

Familial amyotrophic lateral sclerosis

The increasing complexity of the pathways implicated in the pathogenesis of familial amyotrophic lateral sclerosis (ALS) has stimulated intensive research in many directions. Genetic analysis of familial ALS has yielded six loci and one disease gene (SOD1), initially suggesting a role for free radicals in the disease process, although the mechanisms through which the mutant exerts toxicity and results in selective motor neuron death remain uncertain. Numerous studies have focused on structural elements of the affected cell, emphasizing the role of neurofilaments and peripherin and their functional disruption in disease. Other topics examined include cellular homeostasis of copper and calcium, particularly in the context of oxidative stress and the processes of protein aggregation, glutamate excitotoxicity, and apoptosis. It has become evident that there is considerable interplay between these mechanisms and, as the role of each is established, a common picture may emerge, enabling the development of more targeted therapies. This study discusses the main areas of investigation and reviews the findings.

Increased oxidative damage to DNA in ALS patients

Although the cause of amyotrophic lateral sclerosis (ALS) is unknown, substantial evidence indicates that oxidative toxicity is associated with neuronal death in this disease. We examined levels of a well-established marker of oxidative damage to DNA, 8-hydroxy-2'-deoxyguanosine (8OH2'dG) in plasma, urine, and cerebrospinal fluid (CSF) at a single time point from subjects with ALS, other neurological diseases, or no known disorders. We also measured the rate of change of 8OH2'dG levels in plasma and urine from ALS and in urine from control subjects over 9 months and examined the relationship to disease severity. In each fluid, 8OH2'dG levels were significantly elevated in the ALS group as compared to control subjects. In all subjects, the plasma and CSF 8OH2'dG levels increased with age, providing further evidence for a role of oxidative damage in normal aging. Plasma and urine 8OH2'dG levels increased significantly with time in the ALS group only. The rate of increase in urine 8OH2'dG levels with time was significantly correlated with disease severity. These findings are consistent with the hypothesis that oxidative pathology accompanies the neurodegenerative process in ALS and suggest that 8OH2'dG may provide a useful tool for monitoring therapeutic interventions in this disease.