Amyotrophic Lateral Sclerosis: What Role Does Environment Play?

The Interplay Between Neuroinfections, the Immune System and Neurological Disorders: A Focus on Africa

Neurological disorders related to neuroinfections are highly prevalent in Sub-Saharan Africa (SSA), constituting a major cause of disability and economic burden for patients and society. These include epilepsy, dementia, motor neuron diseases, headache disorders, sleep disorders, and peripheral neuropathy. The highest prevalence of human immunodeficiency virus (HIV) is in SSA. Consequently, there is a high prevalence of neurological disorders associated with HIV infection such as HIV-associated neurocognitive disorders, motor disorders, chronic headaches, and peripheral neuropathy in the region. The pathogenesis of these neurological disorders involves the direct role of the virus, some antiretroviral treatments, and the dysregulated immune system. Furthermore, the high prevalence of epilepsy in SSA (mainly due to perinatal causes) is exacerbated by infections such as toxoplasmosis, neurocysticercosis, onchocerciasis, malaria, bacterial meningitis, tuberculosis, and the immune reactions they elicit. Sleep disorders are another common problem in the region and have been associated with infectious diseases such as human African trypanosomiasis and HIV and involve the activation of the immune system. While most headache disorders are due to benign primary headaches, some secondary headaches are caused by infections (meningitis, encephalitis, brain abscess). HIV and neurosyphilis, both common in SSA, can trigger long-standing immune activation in the central nervous system (CNS) potentially resulting in dementia. Despite the progress achieved in preventing diseases from the poliovirus and retroviruses, these microbes may cause motor neuron diseases in SSA. The immune mechanisms involved in these neurological disorders include increased cytokine levels, immune cells infiltration into the CNS, and autoantibodies. This review focuses on the major neurological disorders relevant to Africa and neuroinfections highly prevalent in SSA, describes the interplay between neuroinfections, immune system, neuroinflammation, and neurological disorders, and how understanding this can be exploited for the development of novel diagnostics and therapeutics for improved patient care.

Histone Methylation Regulation in Neurodegenerative Disorders

Advances achieved with molecular biology and genomics technologies have permitted investigators to discover epigenetic mechanisms, such as DNA methylation and histone posttranslational modifications, which are critical for gene expression in almost all tissues and in brain health and disease. These advances have influenced much interest in understanding the dysregulation of epigenetic mechanisms in neurodegenerative disorders. Although these disorders diverge in their fundamental causes and pathophysiology, several involve the dysregulation of histone methylation-mediated gene expression. Interestingly, epigenetic remodeling via histone methylation in specific brain regions has been suggested to play a critical function in the neurobiology of psychiatric disorders, including that related to neurodegenerative diseases. Prominently, epigenetic dysregulation currently brings considerable interest as an essential player in neurodegenerative disorders, such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), Amyotrophic lateral sclerosis (ALS) and drugs of abuse, including alcohol abuse disorder, where it may facilitate connections between genetic and environmental risk factors or directly influence disease-specific pathological factors. We have discussed the current state of histone methylation, therapeutic strategies, and future perspectives for these disorders. While not somatically heritable, the enzymes responsible for histone methylation regulation, such as histone methyltransferases and demethylases in neurons, are dynamic and reversible. They have become promising potential therapeutic targets to treat or prevent several neurodegenerative disorders. These findings, along with clinical data, may provide links between molecular-level changes and behavioral differences and provide novel avenues through which the epigenome may be targeted early on in people at risk for neurodegenerative disorders.

Stem cells for ALS: An overview of possible therapeutic approaches

Amyotrophic lateral sclerosis (ALS) is an unusual, fatal, neurodegenerative disorder leading to the loss of motor neurons. After diagnosis, the average lifespan ranges from 3 to 5 years, and death usually results from respiratory failure. Although the pathogenesis of ALS remains unclear, multiple factors are thought to contribute to the progression of ALS, such as network interactions between genes, environmental exposure, impaired molecular pathways and many others. The neuroprotective properties of neural stem cells (NSCs) and the paracrine signaling of mesenchymal stem cells (MSCs) have been examined in multiple pre-clinical trials of ALS with promising results. The data from these initial trials indicate a reduction in the rate of disease progression. The mechanism through which stem cells achieve this reduction is of major interest. Here, we review the to-date pre-clinical and clinical therapeutic approaches employing stem cells, and discuss the most promising ones.

Association of Environmental Toxins With Amyotrophic Lateral Sclerosis

IMPORTANCE

Persistent environmental pollutants may represent a modifiable risk factor involved in the gene-time-environment hypothesis in amyotrophic lateral sclerosis (ALS).

OBJECTIVE

To evaluate the association of occupational exposures and environmental toxins on the odds of developing ALS in Michigan.

DESIGN, SETTING, AND PARTICIPANTS

Case-control study conducted between 2011 and 2014 at a tertiary referral center for ALS. Cases were patients diagnosed as having definitive, probable, probable with laboratory support, or possible ALS by revised El Escorial criteria; controls were excluded if they were diagnosed as having ALS or another neurodegenerative condition or if they had a family history of ALS in a first- or second-degree blood relative. Participants completed a survey assessing occupational and residential exposures. Blood concentrations of 122 persistent environmental pollutants, including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and brominated flame retardants (BFRs), were measured using gas chromatography-mass spectrometry. Multivariable models with self-reported occupational exposures in various exposure time windows and environmental toxin blood concentrations were separately fit by logistic regression models. Concordance between the survey data and pollutant measurements was assessed using the nonparametric Kendall τ correlation coefficient.

MAIN OUTCOMES AND MEASURES

Occupational and residential exposures to environmental toxins, and blood concentrations of 122 persistent environmental pollutants, including OCPs, PCBs, and BFRs.

RESULTS

Participants included 156 cases (mean [SD] age, 60.5 [11.1] years; 61.5% male) and 128 controls (mean [SD] age, 60.4 [9.4] years; 57.8% male); among them, 101 cases and 110 controls had complete demographic and pollutant data. Survey data revealed that reported pesticide exposure in the cumulative exposure windows was significantly associated with ALS (odds ratio [OR] = 5.09; 95% CI, 1.85-13.99; P = .002). Military service was also associated with ALS in 2 time windows (exposure ever happened in entire occupational history: OR = 2.31; 95% CI, 1.02-5.25; P = .046; exposure ever happened 10-30 years ago: OR = 2.18; 95% CI, 1.01-4.73; P = .049). A multivariable model of measured persistent environmental pollutants in the blood, representing cumulative occupational and residential exposure, showed increased odds of ALS for 2 OCPs (pentachlorobenzene: OR = 2.21; 95% CI, 1.06-4.60; P = .04; and cis-chlordane: OR = 5.74; 95% CI, 1.80-18.20; P = .005), 2 PCBs (PCB 175: OR = 1.81; 95% CI, 1.20-2.72; P = .005; and PCB 202: OR = 2.11; 95% CI, 1.36-3.27; P = .001), and 1 BFR (polybrominated diphenyl ether 47: OR = 2.69; 95% CI, 1.49-4.85; P = .001). There was modest concordance between survey data and the measurements of persistent environmental pollutants in blood; significant Kendall τ correlation coefficients ranged from -0.18 (Dacthal and "use pesticides to treat home or yard") to 0.24 (trans-nonachlor and "store lawn care products in garage").

CONCLUSIONS AND RELEVANCE

In this study, persistent environmental pollutants measured in blood were significantly associated with ALS and may represent modifiable ALS disease risk factors.

Expression of microRNAs in human post-mortem amyotrophic lateral sclerosis spinal cords provides insight into disease mechanisms

Amyotrophic lateral sclerosis is a late-onset and terminal neurodegenerative disease. The majority of cases are sporadic with unknown causes and only a small number of cases are genetically linked. Recent evidence suggests that post-transcriptional regulation and epigenetic mechanisms, such as microRNAs, underlie the onset and progression of neurodegenerative disorders; therefore, altered microRNA expression may result in the dysregulation of key genes and biological pathways that contribute to the development of sporadic amyotrophic lateral sclerosis. Using systems biology analyses on postmortem human spinal cord tissue, we identified dysregulated mature microRNAs and their potential targets previously implicated in functional process and pathways associated with the pathogenesis of ALS. Furthermore, we report a global reduction of mature microRNAs, alterations in microRNA processing, and support for a role of the nucleotide binding protein, TAR DNA binding protein 43, in regulating sporadic amyotrophic lateral sclerosis-associated microRNAs, thereby offering a potential underlying mechanism for sporadic amyotrophic lateral sclerosis.

Assisting persons with advanced amyotrophic lateral sclerosis in their leisure engagement and communication needs with a basic technology-aided program

BACKGROUND

Eye-tracking communication devices and brain-computer interfaces are the two resources available to help people with advanced amyotrophic lateral sclerosis (ALS) avoid isolation and passivity.

OBJECTIVE

This study was aimed at assessing a technology-aided program (i.e., a third possible resource) for five patients with advanced ALS who needed support for communication and leisure activities.

METHODS

The participants were exposed to baseline and intervention conditions. The technology-aided program, which was used during the intervention, (a) included the communication and leisure options that each participant considered important for him or her (e.g., music, videos, statements/requests, and text messaging) and (b) allowed the participant to access those options with minimal responses (e.g., finger movement or eyelid closure) monitored via microswitches.

RESULTS

The participants started leisure and communication engagement independently only during the intervention (i.e., when the program was used). The mean percentages of session time spent in those forms of engagement were between about 60 and 80. Preference checks and brief interviews indicated that participants and families liked the program.

CONCLUSIONS

The program might be viewed as an additional approach/resource for patients with advanced ALS.

A meta-analysis of observational studies of the association between chronic occupational exposure to lead and amyotrophic lateral sclerosis

OBJECTIVE

The association between occupational exposure to lead and amyotrophic lateral sclerosis (ALS) was examined through systematic review and meta-analyses of relevant epidemiological studies and reported according to PRISMA guidelines.

METHODS

Relevant studies were searched in multiple bibliographic databases through September 2013; additional articles were tracked through PubMed until submission. All records were screened in DistillerSR, and the data extracted from included articles were synthesized with meta-analysis.

RESULTS

The risk of developing ALS among individuals with a history of exposure to lead was almost doubled (odds ratio, 1.81; 95% confidence interval, 1.39 to 2.36) on the basis of nine included case-control studies with specific lead exposure information, with no apparent heterogeneity across included studies (I = 14%). The attributable risk of ALS because of exposure to lead was estimated to be 5%.

CONCLUSIONS

Previous exposure to lead may be a risk factor for ALS.

Motor Neuron Diseases in Sub-Saharan Africa: The Need for More Population-Based Studies

Motor neuron diseases (MNDs) are devastating neurological diseases that are characterised by gradual degeneration and death of motor neurons. Major types of MNDs include amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). These diseases are incurable, with limited disease-modifying treatment options. In order to improve MND-based biomedical research, drug development, and clinical care, population-based studies will be important. These studies, especially among less-studied populations, might identify novel factors controlling disease susceptibility and resistance. To evaluate progress in MND research in Africa, we examined the published literature on MNDs in Sub-Saharan Africa to identify disease prevalence, genetic factors, and other risk factors. Our findings indicate that the amount of research evidence on MNDs in Sub-Saharan Africa is scanty; molecular and genetics-based studies are particularly lacking. While only a few genetic studies were identified, these studies strongly suggest that there appear to be population-specific causes of MNDs among Africans. MND genetic underpinnings vary among different African populations and also between African and non-African populations. Further studies, especially molecular, genetic and genomic studies, will be required to advance our understanding of MND biology among African populations. Insights from these studies would help to improve the timeliness and accuracy of clinical diagnosis and treatment.

Amyotrophic lateral sclerosis: mechanisms and therapeutics in the epigenomic era

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease of the motor neurons, which results in weakness and atrophy of voluntary skeletal muscles. Treatments do not modify the disease trajectory effectively, and only modestly improve survival. A complex interaction between genes, environmental exposure and impaired molecular pathways contributes to pathology in patients with ALS. Epigenetic mechanisms control the hereditary and reversible regulation of gene expression without altering the basic genetic code. Aberrant epigenetic patterns-including abnormal microRNA (miRNA) biogenesis and function, DNA modifications, histone remodeling, and RNA editing-are acquired throughout life and are influenced by environmental factors. Thus, understanding the molecular processes that lead to epigenetic dysregulation in patients with ALS might facilitate the discovery of novel therapeutic targets and biomarkers that could reduce diagnostic delay. These achievements could prove crucial for successful disease modification in patients with ALS. We review the latest findings regarding the role of miRNA modifications and other epigenetic mechanisms in ALS, and discuss their potential as therapeutic targets.

The emerging role of 5-hydroxymethylcytosine in neurodegenerative diseases

DNA methylation primarily occurs within human cells as a 5-methylcytosine (5mC) modification of the cytosine bases in CpG dinucleotides. 5mC has proven to be an important epigenetic mark that is involved in the control of gene transcription for processes such as development and differentiation. However, recent studies have identified an alternative modification, 5-hydroxymethylcytosine (5hmC), which is formed by oxidation of 5mC by ten-eleven translocation (TET) enzymes. The overall levels of 5hmC in the mammalian genome are approximately 10% of 5mC levels, although higher levels have been detected in tissues of the central nervous system (CNS). The functions of 5hmC are not yet fully known, but evidence suggests that 5hmC may be both an intermediate product during the removal of 5mC by passive or active demethylation processes and also an epigenetic modification in its own right, regulating chromatin or transcriptional factors involved in processes such as neurodevelopment or environmental stress response. This review highlights our current understanding of the role that 5hmC plays in neurodegenerative diseases, including Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), fragile X-associated tremor/ataxia syndrome (FXTAS), Friedreich ataxia (FRDA), Huntington's disease (HD), and Parkinson's disease (PD).

Amyotrophic lateral sclerosis and agricultural environments: a systematic review

The aim of this study was to examine the relationship between the risk of amyotrophic lateral sclerosis (ALS) and exposure to rural environments. Studies were identified through OVID MEDLINE and EMBASE search up to September 2013 using as keywords rural residence, farmers, and pesticide exposure. Twenty-two studies were included for this meta-analysis. Summary odds ratios (ORs) were calculated using random effect model by type of exposure index, and subgroup analyses were conducted according to study design, gender, region, case ascertainment, and exposure assessment. The risk of ALS was significantly increased with pesticide exposure (OR, 1.44; 95% CI, 1.22-1.70) and with farmers (OR, 1.42; 95% CI, 1.17-1.73), but was not significant with rural residence (OR, 1.25; 95% CI, 0.84-1.87). The risk estimates for subgroup analysis between pesticide exposure and ALS indicated a significant positive association with men (OR, 1.96), and in studies using El Escorial criteria for ALS definition (OR, 1.63) and expert judgment for pesticide exposure (OR, 2.04) as well. No significant publication bias was observed. Our findings support the association of pesticide exposure and an increased risk for ALS, stressing that the use of more specific exposure information resulted in more significant associations.

Intermediate CAG repeat expansion in the ATXN2 gene is a unique genetic risk factor for ALS--a systematic review and meta-analysis of observational studies

Amyotrophic lateral sclerosis (ALS) is a rare degenerative condition of the motor neurons. Over 10% of ALS cases are linked to monogenic mutations, with the remainder thought to be due to other risk factors, including environmental factors, genetic polymorphisms, and possibly gene-environmental interactions. We examined the association between ALS and an intermediate CAG repeat expansion in the ATXN2 gene using a meta-analytic approach. Observational studies were searched with relevant disease and gene terms from MEDLINE, EMBASE, and PsycINFO from January 2010 through to January 2014. All identified articles were screened using disease terms, gene terms, population information, and CAG repeat information according to PRISMA guidelines. The final list of 17 articles was further evaluated based on the study location, time period, and authors to exclude multiple usage of the same study populations: 13 relevant articles were retained for this study. The range 30-33 CAG repeats in the ATXN2 gene was most strongly associated with ALS. The meta-analysis revealed that the presence of an intermediate CAG repeat (30-33) in the ATXN2 gene was associated with an increased risk of ALS [odds ratio (OR) = 4.44, 95%CI: 2.91-6.76)] in Caucasian ALS patients. There was no significant difference in the association of this CAG intermediate repeat expansion in the ATXN2 gene between familial ALS cases (OR = 3.59, 1.58-8.17) and sporadic ALS cases (OR = 3.16, 1.88-5.32). These results indicate that the presence of intermediate CAG repeat expansion in the ATXN2 gene is a specific genetic risk factor for ALS, unlike monogenic mutations with an autosomal dominant transmission mode, which cause a more severe phenotype of ALS, with a higher prevalence in familial ALS.

Environmental risk factors and amyotrophic lateral sclerosis (ALS): a case-control study of ALS in Michigan

An interim report of a case-control study was conducted to explore the role of environmental factors in the development of amyotrophic lateral sclerosis (ALS). Sixty-six cases and 66 age- and gender-matched controls were recruited. Detailed information regarding residence history, occupational history, smoking, physical activity, and other factors was obtained using questionnaires. The association of ALS with potential risk factors, including smoking, physical activity and chemical exposure, was investigated using conditional logistic regression models. As compared to controls, a greater number of our randomly selected ALS patients reported exposure to fertilizers to treat private yards and gardens and occupational exposure to pesticides in the last 30 years than our randomly selected control cases. Smoking, occupational exposures to metals, dust/fibers/fumes/gas and radiation, and physical activity were not associated with ALS when comparing the randomly selected ALS patients to the control subjects. To further explore and confirm results, exposures over several time frames, including 0-10 and 10-30 years earlier, were considered, and analyses were stratified by age and gender. Pesticide and fertilizer exposure were both significantly associated with ALS in the randomly selected ALS patients. While study results need to be interpreted cautiously given the small sample size and the lack of direct exposure measures, these results suggest that environmental and particularly residential exposure factors warrant close attention in studies examining risk factors of ALS.

Two Men with Advanced Amyotrophic Lateral Sclerosis Operate a Computer-Aided Television System through Mouth or Throat Microswitches

This study assessed a simple technology to enable two men affected by amyotrophic lateral sclerosis, in an advanced stage (i.e., with pervasive motor disabilities and lack of speech), to operate a computer-aided television system. The technology included microswitches, a portable computer, an interface connecting the microswitches to the computer, a commercial software package to allow the possibility of watching television via computer, and specific software to allow microswitch activations to be recorded as forward commands for channel change. The participants (a) gained control over the television programs to watch or not to watch (i.e., through channel changes) and (b) showed increased attention to the programs (i.e., an increase in their watching time). The practical relevance of the findings, the integration of the technology used in this study within the participants' wider recreation and communication program, and ways of extending the research were discussed.

Effects of diabetes mellitus on amyotrophic lateral sclerosis: a systematic review

Background

Amyotrophic lateral sclerosis (ALS) is an incurable motor neuron degenerative disease which onset and course may be affected by concurrent diabetes mellitus (DM). We performed a systematic review to assess the effect of DM/dysglycemic states on ALS.

Methods

We searched PubMed MEDLINE, from inception to March 2013 for original articles published in English and in French languages on DM (and related states) and ALS. We made no restriction per study designs.

Results

Seven studies/1410 citations (5 case–control and 2 cross-sectional) were included in the final selection. The number of participants with ALS ranged from 18 to 2371. The outcome of interest was ALS and DM/dysglycemic states respectively in three and two case control-studies. DM/impaired glucose tolerance status did not affect disease progression, survival, disease severity and disease duration in ALS participants but ALS participants with DM were found to be older in one study. DM/IGT prevalence was similar in both ALS and non ALS participants. This review was limited by the absence of prospective cohort studies and the heterogeneity in ALS and DM diagnosis criteria.

Conclusions

This systematic review suggests that evidences for the association of ALS and DM are rather limited and derived from cross-sectional studies. Prospective studies supplemented by ALS registries and animal studies are needed to better understand the relationship between both conditions.

Nutritional care in motor neurone disease/ amyotrophic lateral sclerosis

Patients with amyotrophic lateral sclerosis (ALS) often present changes in nutritional status. Based on weight loss and on difficulty in nutritional management, this study aims to review the different possibilities and to present guidelines concerning nutritional treatment to such patients. Diet characteristics, types of treatment and nutritional therapy indicating administration routes and discussing the details of the disease are described herein. Nutritional therapy has been a substantial therapeutic resource for ALS development.

A man with amyotrophic lateral sclerosis uses a mouth pressure microswitch to operate a text messaging system with a word prediction function

OBJECTIVE

To assess whether a man with amyotrophic lateral sclerosis could benefit from using (a) a mouth pressure microswitch instead of an optic microswitch activated via head movement and (b) a special word prediction function within a text messaging system.

METHOD

Initially, both microswitches were used for operating the text messaging system, and their effectiveness and the man's preference were assessed. Subsequently, only the mouth microswitch was used and the messaging system was provided with a word prediction function.

RESULTS

The man was more efficient/rapid in using the text messaging (i.e., in writing) with the mouth microswitch and preferred such a microswitch. Similarly, he was more rapid in writing when the word prediction function was added (as opposed to the initial phase of the study when such function was not available) and preferred to use it.

CONCLUSION

Technology updates are critical in helping persons with motor degeneration.

A voice-sensitive microswitch for a man with amyotrophic lateral sclerosis and pervasive motor impairment

OBJECTIVE

To assess a voice-sensitive microswitch for a 67-year-old man with amyotrophic lateral sclerosis (ALS) who had difficulties continuing to use an optic microswitch through small chin movements.

METHOD

The man used the microswitches in combination with a computer-aided program to (a) access preferred songs and videos or make requests, and (b) operate a messaging system to communicate with his wife and sons. To assess the man's performance with the two microswitches, we alternated sessions with one microswitch with sessions with the other.

RESULTS

The man's performance with the new microswitch was apparently more efficient (i.e. he could generally activate the new microswitch with a single attempt while he needed a mean of about two attempts for each activation of the optic microswitch). The man also developed a clear preference for the new microswitch.

CONCLUSION

Technology updates are critical within programs for persons with motor degeneration.

IMPLICATIONS FOR REHABILITATION

A microswitch that can be used efficiently and without effort is critically important for a person with ALS. The microswitch can be used with programs that allow the person to manage leisure stimulus events, request opportunities and/or text messaging communication. The microswitch needs to be updated (changed) in relation to the person's physical deterioration.

Identification of epigenetically altered genes in sporadic amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a terminal disease involving the progressive degeneration of motor neurons within the motor cortex, brainstem and spinal cord. Most cases are sporadic (sALS) with unknown causes suggesting that the etiology of sALS may not be limited to the genotype of patients, but may be influenced by exposure to environmental factors. Alterations in epigenetic modifications are likely to play a role in disease onset and progression in ALS, as aberrant epigenetic patterns may be acquired throughout life. The aim of this study was to identify epigenetic marks associated with sALS. We hypothesize that epigenetic modifications may alter the expression of pathogenesis-related genes leading to the onset and progression of sALS. Using ELISA assays, we observed alterations in global methylation (5 mC) and hydroxymethylation (5 HmC) in postmortem sALS spinal cord but not in whole blood. Loci-specific differentially methylated and expressed genes in sALS spinal cord were identified by genome-wide 5mC and expression profiling using high-throughput microarrays. Concordant direction, hyper- or hypo-5mC with parallel changes in gene expression (under- or over-expression), was observed in 112 genes highly associated with biological functions related to immune and inflammation response. Furthermore, literature-based analysis identified potential associations among the epigenes. Integration of methylomics and transcriptomics data successfully revealed methylation changes in sALS spinal cord. This study represents an initial identification of epigenetic regulatory mechanisms in sALS which may improve our understanding of sALS pathogenesis for the identification of biomarkers and new therapeutic targets.

Regulation of FMO and PON detoxication systems in ALS human tissues

Amyotrophic lateral sclerosis (ALS) is an adult-onset, progressive, and fatal neurodegenerative disease with unknown etiology. Recent evidence suggests an association between the exposure to toxic environmental factors and sporadic ALS. The flavin-containing monooxygenases (FMOs) and paraoxonase (PONs) genes encode enzymes involved in xenobiotic detoxication and are associated with ALS. FMO and PON gene expression has been examined in the human central nervous system including human brain subregions defined as the spinal cord, medulla, and cerebral cortex and in the peripheral tissues (lymphocytes, fibroblasts) in ALS patients and normal control subjects. FMO expression was generally higher in tissues from ALS subjects than in control tissues, with the largest increases in FMO expression detected in the spinal cord. In peripheral tissues, the FMO mRNA level was found to be lower compared with FMO expression in brain tissue, and no differences were detected between ALS patients and the control tissue. FMO and PON gene expression was low in peripheral tissues. In contrast to FMO5 expression, the PON2 gene was down-regulated in ALS patients compared to the controls. Because FMO and PON are involved in the detoxication processes and their functional activity to bioactivate chemicals to toxins has been documented, the data herein suggest that environmental toxin exposure may play a role in a subset of individuals who contract ALS by altering FMO and PON gene expression. Although the precise pathogenic link is presently unknown, these findings suggest a role at FMO and PON genes in the development of ALS.

Technology-aided programs for assisting communication and leisure engagement of persons with amyotrophic lateral sclerosis: two single-case studies

Technology-aided programs for assisting communication and leisure engagement were assessed in single-case studies involving two men with amyotrophic lateral sclerosis (ALS). Study I involved a 51-year-old man with a virtually total loss of his motor repertoire and assessed a technology-aided program aimed at enabling him to (a) write and send out text messages and have incoming messages read to him and (b) establish videophone connections with his children (i.e., establish video contact and communicate with them). Study II involved a 66-year-old man with virtually no motor behavior and apparent depression and assessed a technology-aided program aimed at enabling him to (a) engage in leisure activities and make requests for basic needs and (b) use a low-demand messaging system. The results of both studies were highly encouraging. The participant of Study I could use the technology-aided program for effective communication and social interaction with multiple partners as well as for family interaction. The participant of Study II could use the technology-aided program for leisure engagement, requests, and basic family contacts/communication. The implications of technology for helping persons with severe ALS levels maintain an active and constructive role are discussed.

A technology-aided program to support leisure engagement and communication by a man with amyotrophic lateral sclerosis

OBJECTIVE

To assess a technology-aided programme for promoting leisure engagement and communication in a man with amyotrophic lateral sclerosis (ALS).

METHOD

The programme involved a laptop computer equipped with a Clicker 5 software package, an optic microswitch and an interface device. The participant could choose between two leisure options (i.e. songs and videos), could write requests and general messages through a virtual keyboard and a microswitch and could have the written text read out to caregivers and staff.

RESULTS

The use of the programme increased the mean frequency of words written to about 15 per 20-minute session during the second intervention phase. Those words were used by the participant for formulating a mean of over two requests/messages per session. The participant also listened to songs and watched videos.

CONCLUSION

A simple technology-aided programme may allow ALS patients to manage leisure engagement and communication.

Cause or Effect: Misregulation of microRNA Pathways in Neurodegeneration

During normal aging or neurodegenerative diseases, neuronal survival and function depend on protein homeostasis, which is regulated by multiple mechanisms, including the microRNA (miRNA) pathway. In different cells types, the absence of Dicer, a key miRNA processing enzyme, leads to neurodegeneration through cell-autonomous and non-cell-autonomous mechanisms. Loss of certain miRNAs also causes neurodegeneration in some model organisms. On the other hand, miRNA expression is misregulated in patients with different neurodegenerative diseases. Thus, the miRNA pathway appears to be essential in the pathogenesis of several age-dependent neurodegenerative conditions; however, our understanding of the underlying mechanism remains rudimentary. The precise causal relationships between specific miRNAs and neurodegeneration in humans need to be further investigated.