Geographic Analysis of Motor Neuron Disease Mortality and Heavy Metals Released to Rivers in Spain

The etiology of motor neuron disease (MND) is still unknown. The aims of this study were to: (1) analyze MND mortality at a fine-grained level; and (2) explore associations of MND and heavy metals released into Spanish river basins. MND deaths were extracted from the Spanish nationwide mortality registry (2007⁻2016). Standardized mortality ratios (SMRs) for MND were estimated at a municipal level. Sites that emitted quantities of heavy metals above the regulatory thresholds were obtained from the European Pollutant Release and Transfer Register database (2007⁻2015). The relative risks for non-exposed and exposed municipalities (considering a downstream 20 km river section) by type of heavy metal were analyzed using a log-linear model. SMRs were significantly higher in central and northern municipalities. SMRs were 1.14 (1.10⁻1.17) higher in areas exposed to heavy metals than in non-exposed areas: 0.95 (0.92⁻0.96). Considering the different metals, we found the following increased MND death risks in exposed areas: 20.9% higher risk for lead, 20.0% for zinc, 16.7% for arsenic, 15.7% for chromium, 15.4% for cadmium, 12.7% for copper, and 12.4% for mercury. This study provides associations between MND death risk and heavy metals in exposed municipalities. Further studies investigating heavy metal exposure are needed to progress in MND understanding.

Nutrition management methods effective in increasing weight, survival time and functional status in ALS patients: a systematic review

Poor prognosis and decreased survival time correlate with the nutritional status of patients with amyotrophic lateral sclerosis (ALS). Various studies were reviewed which assessed weight, body mass index (BMI), survival time and ALS functional rating scale revised (ALSFRS-R) in order to determine the best nutrition management methods for this patient population. A systematic review was conducted using CINAHL, Medline, and PubMed, and various search terms in order to determine the most recent clinical trials and observational studies that have been conducted concerning nutrition and ALS. Four articles met criteria to be included in the review. Data were extracted from these articles and were inputted into the Data Extraction Tool (DET) provided by the Academy of Nutrition and Dietetics (AND). Results showed that nutrition supplementation does promote weight stabilisation or weight gain in individuals with ALS. Given the low risk and low cost associated with intervention, early and aggressive nutrition intervention is recommended. This systematic review shows that there is a lack of high quality evidence regarding the efficacy of any dietary interventions for promoting survival in ALS or slowing disease progression; therefore more research is necessary related to effects of nutrition interventions.

Mechanical ventilation for amyotrophic lateral sclerosis/motor neuron disease

BACKGROUND

Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease, is a fatal neurodegenerative disease. Neuromuscular respiratory failure is the most common cause of death, which usually occurs within two to five years of the disease onset. Supporting respiratory function with mechanical ventilation may improve survival and quality of life. This is the second update of a review first published in 2009.

OBJECTIVES

To assess the effects of mechanical ventilation (tracheostomy-assisted ventilation and non-invasive ventilation (NIV)) on survival, functional measures of disease progression, and quality of life in ALS, and to evaluate adverse events related to the intervention.

SEARCH METHODS

We searched the Cochrane Neuromuscular Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL Plus, and AMED on 30 January 2017. We also searched two clinical trials registries for ongoing studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs involving non-invasive or tracheostomy-assisted ventilation in participants with a clinical diagnosis of ALS, independent of the reported outcomes. We included comparisons with no intervention or the best standard care.

DATA COLLECTION AND ANALYSIS

For the original review, four review authors independently selected studies for assessment. Two review authors reviewed searches for this update. All review authors independently extracted data from the full text of selected studies and assessed the risk of bias in studies that met the inclusion criteria. We attempted to obtain missing data where possible. We planned to collect adverse event data from the included studies.

MAIN RESULTS

For the original Cochrane Review, the review authors identified two RCTs involving 54 participants with ALS receiving NIV. There were no new RCTs or quasi-RCTs at the first update. One new RCT was identified in the second update but was excluded for the reasons outlined below.Incomplete data were available for one published study comparing early and late initiation of NIV (13 participants). We contacted the trial authors, who were not able to provide the missing data. The conclusions of the review were therefore based on a single study of 41 participants comparing NIV with standard care. Lack of (or uncertain) blinding represented a risk of bias for participant- and clinician-assessed outcomes such as quality of life, but it was otherwise a well-conducted study with a low risk of bias.The study provided moderate-quality evidence that overall median survival was significantly different between the group treated with NIV and the standard care group. The median survival in the NIV group was 48 days longer (219 days compared to 171 days for the standard care group (estimated 95% confidence interval 12 to 91 days, P = 0.0062)). This survival benefit was accompanied by an enhanced quality of life. On subgroup analysis, in the subgroup with normal to moderately impaired bulbar function (20 participants), median survival was 205 days longer (216 days in the NIV group versus 11 days in the standard care group, P = 0.0059), and quality of life measures were better than with standard care (low-quality evidence). In the participants with poor bulbar function (21 participants), NIV did not prolong survival or improve quality of life, although there was significant improvement in the mean symptoms domain of the Sleep Apnea Quality of Life Index by some measures. Neither trial reported clinical data on intervention-related adverse effects.

AUTHORS' CONCLUSIONS

Moderate-quality evidence from a single RCT of NIV in 41 participants suggests that it significantly prolongs survival, and low-quality evidence indicates that it improves or maintains quality of life in people with ALS. Survival and quality of life were significantly improved in the subgroup of people with better bulbar function, but not in those with severe bulbar impairment. Adverse effects related to NIV should be systematically reported, as at present there is little information on this subject. More RCT evidence to support the use of NIV in ALS will be difficult to generate, as not offering NIV to the control group is no longer ethically justifiable. Future studies should examine the benefits of early intervention with NIV and establish the most appropriate timing for initiating NIV in order to obtain its maximum benefit. The effect of adding cough augmentation techniques to NIV also needs to be investigated in an RCT. Future studies should examine the health economics of NIV. Access to NIV remains restricted in many parts of the world, including Europe and North America. We need to understand the factors, personal and socioeconomic, that determine access to NIV.

Motor neuron disease mortality and lifetime petrol lead exposure: Evidence from national age-specific and state-level age-standardized death rates in Australia

BACKGROUND

The age standardized death rate from motor neuron disease (MND) for persons 40-84 years of age in the Australian States of New South Wales, Victoria, and Queensland increased dramatically from 1958 to 2013. Nationally, age-specific MND death rates also increased over this time period, but the rate of the rise varied considerably by age-group. The historic use of lead (Pb) additives in Australian petrol is a candidate explanation for these trends in MND mortality (International Classification of Disease (ICD)-10 G12.2).

METHODS

Leveraging temporal and spatial variation in petrol lead exposure risk resulting from the slow rise and rapid phase-out of lead as a constituent in gasoline in Australia, we analyze relationships between (1) national age-specific MND death rates in Australia and age-specific lifetime petrol lead exposure, (2) annual between-age dispersions in age-specific MND death rates and age-specific lifetime petrol lead exposure; and (3) state-level age-standardized MND death rates as a function of age-weighted lifetime petrol lead exposure.

RESULTS

Other things held equal, we find that a one percent increase in lifetime petrol lead exposure increases the MND death rate by about one-third of one percent in both national age-specific and state-level age-standardized models of MND mortality. Lending support to the supposition that lead exposure is a driver of MND mortality risk, we find that the annual between-age group standard deviation in age-specific MND death rates is strongly correlated with the between-age standard deviation in age-specific lifetime petrol lead exposure.

CONCLUSION

Legacy petrol lead emissions are associated with age-specific MND death rates as well as state-level age-standardized MND death rates in Australia. Results indicate that we are approaching peak lead exposure-attributable MND mortality.

Motor neuron disease mortality rates in U.S. states are associated with well water use

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with an unknown cause and invariably fatal outcome. We sought to evaluate a correlation between motor neuron disease (MND) mortality rates and residential radon levels that was previously reported for counties in the United Kingdom. We examined the relationships between age-adjusted MND mortality rates in U.S. states with residential radon levels, well water use, and other variables using structural equation modeling. We observed a significant correlation between MND mortality rates and radon levels. However, in structural equation models, radon did not have a significant, direct effect on MND mortality rates. Conversely, MND mortality rates were significantly and directly predicted by race and by the percentage of the population of each state using well water (p < 0.001 and p = 0.022). We observed similar, significant effects for well water use and MND mortality for males and females separately (p < 0.05). In conclusion, we hypothesize that the association of MND mortality rates with well water use reflects contamination of wells with Legionella, a bacterium common in well water that is known to cause neurologic disease. A Legionella hypothesis is a biologically plausible cause of ALS and suggests new avenues for etiologic research.

A Temporal Association between Accumulated Petrol (Gasoline) Lead Emissions and Motor Neuron Disease in Australia

Background: The age standardised death rate from motor neuron disease (MND) has increased from 1.29 to 2.74 per 100,000, an increase of 112.4% between 1959 and 2013. It is clear that genetics could not have played a causal role in the increased rate of MND deaths over such a short time span. We postulate that environmental factors are responsible for this rate increase. We focus on lead additives in Australian petrol as a possible contributing environmental factor. Methods: The associations between historical petrol lead emissions and MND death trends in Australia between 1962 and 2013 were examined using linear regressions. Results: Regression results indicate best fit correlations between a 20 year lag of petrol lead emissions and age-standardised female death rate (R² = 0.86, p = 4.88 × 10⁻²³), male age standardised death rate (R² = 0.86, p = 9.4 × 10⁻²³) and percent all cause death attributed to MND (R² = 0.98, p = 2.6 × 10⁻⁴⁴). Conclusion: Legacy petrol lead emissions are associated with increased MND death trends in Australia. Further examination of the 20 year lag between exposure to petrol lead and the onset of MND is warranted.

Mechanical ventilation for amyotrophic lateral sclerosis/motor neuron disease

BACKGROUND

Amyotrophic lateral sclerosis, also known as motor neuron disease, is a fatal neurodegenerative disease. Neuromuscular respiratory failure is the commonest cause of death, usually within two to five years of the disease onset. Supporting respiratory function with mechanical ventilation may improve survival and quality of life. This is the first update of a review first published in 2009.

OBJECTIVES

The primary objective of the review is to examine the efficacy of mechanical ventilation (tracheostomy and non-invasive ventilation) in improving survival in ALS. The secondary objectives are to examine the effect of mechanical ventilation on functional measures of disease progression and quality of life in people with ALS; and assess adverse events related to the intervention.

SEARCH METHODS

We searched The Cochrane Neuromuscular Disease Group Specialized Register (1 May 2012), CENTRAL (2012, Issue 4), MEDLINE (January 1966 to April 2012), EMBASE (January 1980 to April 2012), CINAHL Plus (January 1937 to April 2012), and AMED (January 1985 to April 2012). We also searched for ongoing studies on ClinicalTrials.gov.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials involving non-invasive or tracheostomy assisted ventilation in participants with a clinical diagnosis of amyotrophic lateral sclerosis, independent of the reported outcomes. We planned to include comparisons with no intervention or the best standard care.

DATA COLLECTION AND ANALYSIS

For the original review, four authors independently selected studies for assessment and two authors reviewed searches for this update. All authors extracted data independently from the full text of selected studies and assessed the risk of bias in studies that met the inclusion criteria. We attempted to obtain missing data where possible. We planned to collect adverse event data from included studies.

MAIN RESULTS

For the original Cochrane review, the review authors identified and included two randomised controlled trials involving 54 participants with ALS receiving non-invasive ventilation. There were no new randomised or quasi-randomised controlled trials at this first update.Incomplete data were published for one study and we contacted the trial authors who were not able to provide the missing data. Therefore, the results of the review were based on a single study of 41 participants that compared non-invasive ventilation with standard care. It was a well conducted study with low risk of bias.The study showed that the overall median survival was significantly different between the group treated with non-invasive ventilation and the standard care group. The median survival in the non-invasive ventilation group was 48 days longer (219 days compared to 171 days for the standard care group (estimated 95% CI 12 to 91 days, P = 0.0062)). This survival benefit was accompanied by an enhanced quality of life. On subgroup analysis, the survival and quality of life benefit was much more in the subgroup with normal to moderately impaired bulbar function (20 participants); median survival was 205 days longer (216 days in NIV group versus 11 days in the standard care group, P = 0.0059). Non-invasive ventilation did not prolong survival in participants with poor bulbar function (21 participants), although it showed significant improvement in the mean symptoms domain of the Sleep Apnoea Quality of Life Index but not in the Short Form-36 Health Survey Mental Component Summary score. Neither trial reported clinical data on intervention related adverse effects.

AUTHORS' CONCLUSIONS

Evidence from a single randomised trial of non-invasive ventilation in 41 participants suggests that it significantly prolongs survival and improves or maintains quality of life in people with ALS. Survival and some measures of quality of life were significantly improved in the subgroup of people with better bulbar function, but not in those with severe bulbar impairment. Future studies should examine the health economics of NIV and factors influencing access to NIV. We need to understand the factors, personal and socioeconomic, that determine access to NIV.

Creatine for amyotrophic lateral sclerosis/motor neuron disease

BACKGROUND

Creatine, a naturally-occurring nitrogenous organic acid involved in adenosine triphosphate (ATP) production, has been shown to increase survival in mouse models of amyotrophic lateral sclerosis (ALS), also known as motor neuron disease (MND). Results from human trials, however, have been mixed. Given conflicting results regarding the efficacy of creatine, we conducted a systematic review, which was updated in 2012.

OBJECTIVES

To systematically examine the efficacy of creatine efficacy in prolonging ALS survival and in slowing ALS disease progression.

SEARCH METHODS

We searched the Cochrane Neuromuscular Disease Group Specialized Register (16 July 2012), CENTRAL (2012, issue 7 in the Cochrane Library), MEDLINE (January 1966 to July 2012) and EMBASE (January 1980 to July 2012) for any trial involving creatine in the treatment of ALS. We also contacted experts in the field for any additional studies.

SELECTION CRITERIA

Randomized trials of treatment with creatine or placebo in patients diagnosed with ALS. Our primary outcome was tracheostomy-free survival time; secondary outcomes were ALS progression as measured by changes in ALS functional rating revised scores (ALSFRS-R) and per cent predicted forced vital capacity (FVC) over time.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies, assessed risk of bias and extracted data. We obtained and analyzed individual participant data from each study.

MAIN RESULTS

We included three trials involving 386 participants randomized to either creatine 5 to 10 g per day or placebo. When we updated the searches in 2012 we found no additional trials. Creatine was reportedly well-tolerated in all three included studies, with no evidence of renal failure or serious adverse events specifically attributable to creatine. Using a pooled log-rank statistical test, we found no statistical difference in survival between the placebo and creatine groups across all three studies (Chi(2) = 0.09, P = 0.76). In addition, we found no statistical difference in ALSFRS-R slopes between the two groups across all three studies using a pooled linear mixed-effects model (slope difference of +0.03 ALSFRS-R/month in the creatine group; P = 0.76). Interestingly, there was a trend towards slightly worsened FVC slope in the creatine group (slope difference of -0.63 FVC/month in the creatine group) using a pooled linear mixed-effects model across the two studies which included FVC as an outcome, but this difference was not statistically significant (P = 0.054).

AUTHORS' CONCLUSIONS

In patients already diagnosed with clinically probable or definite ALS, creatine at doses ranging from 5 to 10 g per day did not have a statistically significant effect on survival, ALSFRS-R progression or percent predicted FVC progression.

Creatine for amyotrophic lateral sclerosis/motor neuron disease

BACKGROUND

Creatine, a naturally-occurring nitrogenous organic acid involved in adenosine triphosphate (ATP) production, has been shown to increase survival in mouse models of amyotrophic lateral sclerosis (ALS). Results from human trials, however, have been mixed. Given conflicting results regarding creatine's efficacy, we conducted a systematic review.

OBJECTIVES

To systematically examine creatine's efficacy in prolonging ALS survival and in slowing ALS disease progression.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Trials Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library issue 4, 2009), MEDLINE and EMBASE in October 2009 for any trial involving creatine in the treatment of ALS. We also contacted experts in the field for any additional studies.

SELECTION CRITERIA

Randomized trials of treatment with creatine or placebo in patients diagnosed with ALS. Our primary outcome was tracheostomy-free survival time; secondary outcomes were ALS progression as measured by changes in ALS functional rating revised scores (ALSFRS-R) and percent predicted forced vital capacity (FVC) over time.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies, assessed risk of bias and extracted data. We obtained and analyzed individual participant data from each study.

MAIN RESULTS

We included three trials involving 386 participants randomized to either creatine 5 to 10 g per day or placebo. Creatine was reportedly well-tolerated in all three included studies, with no evidence of renal failure or serious adverse events specifically attributable to creatine. Using a pooled log-rank statistical test, we found no statistical difference in survival between the placebo and creatine groups across all three studies (Chi(2) = 0.09, P = 0.76). In addition, we found no statistical difference in ALSFRS-R slopes between the two groups across all three studies using a pooled linear mixed-effects model (slope difference of +0.03 ALSFRS-R/month in the creatine group; P = 0.76). Interestingly, there was a trend towards slightly worsened FVC slope in the creatine group (slope difference of -0.63 FVC/month in the creatine group) using a pooled linear mixed-effects model across the two studies which included FVC as an outcome, but this difference was not statistically significant (P = 0.054).

AUTHORS' CONCLUSIONS

In patients already diagnosed with clinically probable or definite amyotrophic lateral sclerosis (ALS), creatine at doses ranging from 5 to 10 g per day did not have a statistically significant effect on survival, ALS functional rating revised scores (ALSFRS-R) progression or percent predicted forced vital capacity (FVC) progression.

Mechanical ventilation for amyotrophic lateral sclerosis/motor neuron disease

BACKGROUND

Amyotrophic lateral sclerosis, also known as motor neuron disease, is a fatal neurodegenerative disease. Without mechanical ventilation, death from respiratory failure usually follows within two to five years of the onset of symptoms.

OBJECTIVES

To examine the efficacy of mechanical ventilation (tracheostomy and non-invasive ventilation) in improving survival, on disease progression and quality of life in amyotrophic lateral sclerosis.

SEARCH STRATEGY

We searched The Cochrane Neuromuscular Disease Group Trials Specialized Register (December 8 2008), The Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 4, 2008), MEDLINE (January 1966 to December 2008), EMBASE (January 1947 to December 2008), CINAHL Plus (January 1937 to December 2008), and AMED (January 1985 to December 2008). We also searched for ongoing studies on clinicaltrials.gov.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials involving non-invasive or tracheostomy assisted ventilation in participants with a clinical diagnosis of amyotrophic lateral sclerosis.

DATA COLLECTION AND ANALYSIS

Four authors independently selected studies for assessment. All authors extracted data independently from the full text of selected studies and assessed the risk of bias in studies that met the inclusion criteria. We attempted to obtain missing data where possible.

MAIN RESULTS

Two randomised controlled trials involving 54 participants receiving non-invasive ventilation were identified and included. Incomplete data were published for one study and we contacted the trial authors who were not able to provide the missing data. Therefore the results of the review were based on a single study of 41 participants. The study showed that the overall median survival in the whole cohort after initiation of assisted ventilation was significantly different between the non-invasive ventilation and standard care groups (P = 0.0062) with a median survival for the non-invasive ventilation group patients of 48 days longer than the standard care group participants. Non-invasive ventilation significantly improved survival and quality of life in the subgroup with normal to moderately impaired bulbar function. Non-invasive ventilation did not prolong survival in patients with poor bulbar function although it showed significant improvement in the mean symptoms domain of the sleep apnoea quality-of-life index but not in the Short Form-36 quality of life mental component summary score .

AUTHORS' CONCLUSIONS

Evidence from a single randomised trial of non-invasive ventilation in 41 participants suggests that it significantly prolongs survival and improves or maintains quality of life in people with ALS. Survival and some measures of quality of life were significantly improved in the subgroup of people with better bulbar function, but not in those with severe bulbar impairment.

Early-onset neurodegenerative disease of the cerebellum and motor axons

We describe a novel hereditary neurodegenerative disease of infancy affecting an Aboriginal family from northern Manitoba, Canada. The parents are nonconsanguineous, without a family history of neurodegenerative diseases. Four of 10 siblings (three males and one female) presented with neurologic abnormalities including arthrogryposis, seizures, and severe developmental delay shortly after birth. In two children, cerebellar atrophy and mild cerebral atrophy were documented on neuroimaging. Two children, a boy who died at age 40 months and a girl who died at age 22 months, underwent muscle biopsies at 3 weeks and 4 months of age, respectively. The biopsies revealed fiber-size variability in the boy, and grouped atrophy with fiber-type grouping in the girl. Two boys who died at ages 7.5 and 37 months underwent autopsies that indicated severe atrophy of the cerebellar hemispheres (especially the inferior lobules and vermis), hypomyelination of white-matter fascicles in the striatum, severe atrophy of corticospinal tracts in the brainstem and spinal cord, and atrophy of the anterior spinal roots. In the spinal cord, motor neuron cell bodies and the posterior columns were spared. This clinical entity likely represents a novel neurodegenerative disease of the cerebellum and long motor axons.

[Pronostic factors and survival in motor neuron disease]

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is the most common adult motor neuron disease (MND), presenting with a combination of upper (UMN) and lower (lmn) motor neuron signs, with high mortality. other less frequent mnd are progressive muscular atrophy (pma) and primary lateral sclerosis (pls).

OBJECTIVES

To describe demographic data, clinical forms of presentation and evolution of patients with MND, looking for prognostic indicators factors.

METHODS

Retrospective study of a series of patients with MND, registering demographic data, clinical variables and mortality-survival, analyzed by means of statistical package SPSS 6.1.2.

RESULTS

They are 54 patients with MND (50 ALS, 3 PMA and 1 PLS), 30 (55.6%) men and 24 (44.4%) women, bulbar beginning forms in 13 cases (24.1%) and spinal in 41 (75.9%). Average age at beginning 60+/-14 (29-82 years), more delayed in women (p<0.05), and in patients with bulbar form (p<0.05) with clear predominance of female sex (p<0.03). There are 31 dead patients (57.4%) and 23 alive ones (42.6%), with average survival from the beginning symptoms of 46.51+/-40.9 months. Nine months (11-209), observing inversely proportional relation with the age of beginning of the disease (p<0.02). Bulbar beginning forms (p<0.01) and LMN affectation signs, specially bulbar and cervical levels (p<0,005), are associated with a greater probability of dying while the existence of UMN affectation signs on imaging techniques 362 ques has a greater probability of survival (p<0,05).

CONCLUSIONS

The advanced age and the bulbar beginning forms are factors of bad prognosis, specially the predominant affectation of LMN over UMN.

Differentiation Between Primary Lateral Sclerosis and Amyotrophic Lateral Sclerosis

BACKGROUND

Motor neuron diseases can affect the upper motor neuron and/or the lower motor neuron. Both amyotrophic lateral sclerosis (ALS) and primary lateral sclerosis (PLS) are motor neuron diseases, and there is much debate as to whether these are 2 separate disorders or simply 2 points on a continuum.

OBJECTIVE

To determine which clinical features at onset and during follow-up could help differentiate between PLS and ALS.

DESIGN

Retrospective study comparing patients with a diagnosis of PLS or ALS for differences in symptoms or signs at disease onset and during follow-up.

SETTING

Tertiary referral center. Patients Six hundred sixty-one patients with ALS and 43 patients with PLS were included in the study.

RESULTS

At presentation, stiffness was the only symptom that was significantly different between patients with PLS and patients with ALS (observed in 47% and 4% of patients, respectively; P<.001). During follow-up, limb wasting was rare in patients with PLS (2%, compared with 100% in patients with ALS; P<.001). Disease duration was significantly longer in patients with PLS compared with patients with ALS (mean +/- SD, 11.2 +/- 6.1 vs 3.8 +/- 4.2 years, respectively; P<.001). During the 16 years of follow-up, the mortality rate was significantly lower in patients with PLS compared with patients with ALS (only 33% vs 89%, respectively; P<.001).

CONCLUSION

Our findings suggest that a patient presenting with spasticity who does not develop wasting within 3 years most likely has PLS.

Recent Advances in Respiratory Care for Neuromuscular Disease

The impact of ventilatory support on the natural history of neuromuscular disease (NMD) has become clearer over the last 2 decades as techniques have been more widely applied. Noninvasive ventilation (NIV) allows some patients with nonprogressive pathology to live to nearly normal life expectancy, extends survival by many years in patients with other conditions (eg, Duchenne muscular dystrophy), and in those patients with rapidly deteriorating disease (eg, amyotrophic lateral sclerosis) survival may be increased, but symptoms can be palliated even if mortality is not reduced. A growing number of children with NMD are surviving to adulthood with the aid of ventilatory support. The combination of NIV with cough-assist techniques decreases pulmonary morbidity and hospital admissions. Trials have confirmed that NIV works in part by enhancing chemosensitivity, and in patients with many different neuromuscular conditions the most effective time to introduce NIV is when symptomatic sleep-disordered breathing develops.

A retrospective analysis of sleep quality and survival with domiciliary ventilatory support in motor neuron disease

Previous studies have demonstrated that domiciliary ventilatory support improves survival, quality of life and cognitive function in motor neuron disease (MND). These benefits are partly attributed to better sleep quality and less hypoxia. In a retrospective analysis we compared the effect of non-invasive (NPPV, n = 52), tracheostomy (TPPV, n = 23) and no ventilation (n = 43) on sleep and survival in MND patients over a seven-year period. The TPPV and NPPV groups had more sleep arousals (AI, p = 0.024), more respiratory events (p = 0.001) and more time asleep with an oxygen saturation less than 90% (%TST with SpO2<90%, p = 0.01), than those who were not ventilated. After treatment with TPPV or NPPV, the percentage of rapid eye movement sleep increased (p<0.001) and the %TST with Sp02<90% (p = 0.006) and AI (p = 0.001) decreased. Improvements were larger and more consistent with NPPV. The median survival of those who used TPPV was 41 months, NPPV 32 months and of those not ventilated was 25 months, significantly different four years (p = 0.0497) after symptom onset. In this retrospective cohort of MND patients, ventilation, particularly NPPV, markedly improved sleep and conferred a modest survival advantage.

The natural history of primary lateral sclerosis

OBJECTIVE

To define the syndrome of primary lateral sclerosis (PLS) and disorders that contain features of both ALS and PLS, to determine the time beyond which PLS is less likely to become ALS clinically, and to determine the outcome of people with PLS and those who develop lower motor neuron (LMN) signs.

METHODS

The authors reviewed the records of all 39 patients initially diagnosed with PLS in 1984 to 2004. Diagnostic subgroups were defined based on clinical features. The authors used Kaplan-Meier methods to estimate the time to diagnosis, linear regression analyses to assess function, and a Cox proportional hazard model to assess survival in subgroups.

RESULTS

Of the 39 patients, 29 had only upper motor neuron (UMN) signs on initial evaluation. Thirteen of the 29 were later classified as having UMN-dominant ALS (UMN-D) because they acquired evidence of denervation by EMG (3.17 years) or examination (3.67 years). Sixteen of the 29 patients, classified as clinically pure PLS, retained only UMN signs and a normal EMG (mean follow-up 8.7 years). Ten patients who met criteria for ALS at the initial visit were used as controls. The UMN-dominant ALS group had lower functional scores (p = 0.033) than the PLS group, and similar scores to those with ALS. Survival was longer in both the PLS group (p = 0.027) and the UMN-D group (p = 0.067) than the ALS group.

CONCLUSIONS

Clinically pure PLS can be defined by isolated UMN signs 4 years after symptom onset, and is a syndrome of slow progression with high levels of function. Prior to the fourth year, the diagnosis of PLS cannot be made with certainty because many patients develop LMN signs. UMN-dominant ALS, defined by predominantly UMN disease with minor LMN signs, has disability similar to ALS, but slower progression.

[Increase in mortality for motor neuron disease in Italy, 1980-1999]

OBJECTIVE

To describe the mortality rates for motor neuron disease (MND) in Italy both at national level and at three large geographical sub-areas (Northern, Central, Southern Italy).

DESIGN

Deaths for MND are coded accordingly to ICD (IX revision) with 335.2 code. Mortality for MND is analysed for the period 1980-99. Mortality rates are age-standardized on the structure of the 1991 Italian population. Mortality data are derived from the National Institute for Statistics (ISTAT) and are made available by the Epidemiological Database of the Italian National Agency for New Technologies, Energy and the Environment (ENEA).

MAIN OUTCOME MEASURES

Age adjusted mortality rates for MND are calculated for 5-year periods (1980-84, 1985-89, 1990-94, 1995-99) at both national level and three geographical sub-areas (north, center and south); sex and age specific mortality rates are also reported for two decades (1980-89 and 1990-99).

RESULTS

During 1980-99 the annual age-standardized mortality rate in Italy was 1.35 x 100000 in males and 1.10 (x 100000) in females. In the period 1995-99 the mortality rates increased by 39.3% in males and 78.2% in females at national level when compared to 1980-84 rates (1.56 vs 1.12 deaths per 100000 for males and 1.39 vs 0.78 per 100000 for females in 1980-84 and 1995-99, respectively). In the three large geographical sub-areas such increases were 37.6%, 29.7% and 57% in males and 73%, 63.1% and 114.3% in females, respectively.

CONCLUSION

The increase reported in this study is probably due to a mix of different factors as population ageing (age-specific rates reach a peak in the age class 70-74 years), better accuracy of death certificates, adoption of new clinical criteria and at last a wide spread of environmental risk factors (metals, solvents, pesticides, electromagnetic fields) and modification of life style (smoking, diet, professional sport).

Forced vital capacity (FVC) as an indicator of survival and disease progression in an ALS clinic population

In a large cohort of 1034 patients with the diagnosis of definite or probable amyotrophic lateral sclerosis (ALS), the association of forced vital capacity (FVC) at baseline with (a) time to progression of 20 points in Appel ALS (AALS) score or (b) tracheostomy free survival was investigated. The median survival of ALS patients with baseline FVC <75% was 2.91 years, compared with 4.08 years for patients with baseline FVC >75% (p<0.001). Patients with baseline FVC <75% progressed more rapidly (taking 8.0 months to progress 20 AALS points) compared with patients with baseline FVC >75% (10.0 months, p<0.001). Moreover, FVC at first examination was identified as a significant predictor of survival and disease progression in both univariate and multivariate Cox regression models, after adjustment for age, sex, site of onset, diagnostic delay, riluzole therapy, and use of bilateral positive airway pressure and percutaneous endoscopic gastrostomy (p<0.001). We conclude that a single FVC value obtained at an initial visit may serve as a clinically meaningful predictor of survival and disease progression in ALS.

Survival in two variants of tau-negative frontotemporal lobar degeneration: FTLD-U vs FTLD-MND

Pathologic diagnoses in frontotemporal lobar degeneration (FTLD) include tau-positive FTLD and tau-negative FTLD. Two variants of tau-negative FTLD are FTLD with motor neuron disease (FTLD-MND) and FTLD with motor neuron disease type inclusions but without motor neuron disease (FTLD-U). An analysis of patient outcomes in these cases reveals that FTLD-MND has significantly shorter survival than FTLD-U, suggesting that FTLD-MND is a more aggressive disease process.

Age dependent penetrance of three different superoxide dismutase 1 (sod 1) mutations

The age of onset of motor neuron disease in Cu/Zn superoxide dismutase 1 (SOD1) mutation carriers are variable, commencing at any time from the second decade. The authors performed a retrospective analysis of family information in pedigrees dating back to the 1780s, to determine the age-dependent penetrance of three different SOD1 mutations: Glu100Gly, Ile113Thr, and Val148G1y. The penetrance of symptomatic MND in these three SOD1 mutations was greater than 95% by the age of 78. The affected family members with the Val148Gly mutation had the worst prognosis, with a mean age of death of 46.1 years, compared to 54.2 years for the Glu100Gly mutation and 59.9 years for Ile113Thr mutation. Kaplan-Meier survival curves showed that survival of the 3 SOD1 mutation families, when combined, was reduced by nearly 10 years with the mean age of death for all SOD1 mutation carriers being 52.6 years compared to 62.5 years for the control individuals. The SOD1 mutation group also resulted in earlier death compared to sporadic MND, which from natural history studies is 61.4 years. This may reflect that the SOD1 mutation is associated with more progressive and rapid disease, as the age of onset of disease was not earlier. This information would have important implications for genetic counseling of members of individual SOD1 mutation carrier families.

Temporal and geographic variation in United States motor neuron disease mortality, 1969-1998

OBJECTIVE

To describe temporal trends of motor neuron disease (MND) mortality in the United States. Variations in MND by demographic variables of sex, age, geography, and race/ethnicity were evaluated to assess the possible explanations for observed trends.

METHODS

Multiple-cause mortality files from the National Center for Health Statistics for the years 1969 through 1998 were searched for all United States death records with codes corresponding to MND. Age-adjusted mortality rates were calculated by sex, race/ethnicity, age, birth cohort, and place of death.

RESULTS

Overall MND mortality rates increased from 1.25 per 100,000 to 1.82 per 100,000, representing a 46% increase during the 30-year period. Rates among women increased by 60% and continue to rise. Rates among men rose by 35% during this period but have leveled off in the most recent decade evaluated. Mortality rates among African Americans and Hispanics were approximately 50% lower than rates among non-Hispanic whites. A southeast to northwest gradient was observed when rates were grouped by 12 geographic areas. MND mortality rates per 100,000 (and 95% CI) ranged from 2.22 (1.89 to 2.55) in the Northwest to 1.57 (1.44 to 1.71) in the Southeast.

CONCLUSIONS

Variations in motor neuron disease (MND) mortality by time, race/ethnicity, sex, and geography were consistent with the hypothesis that environmental exposures, combined with factors of genetic susceptibility, play a role in the development of MND.

Unexpected decline in survival from amyotrophic lateral sclerosis/motor neurone disease

OBJECTIVES

To describe survival of 1226 Scottish adults with amyotrophic lateral sclerosis/motor neurone disease (ALS/MND).

METHODS

Ten year, prospective, population based disease register. Cox time dependent proportional hazards modelling for multivariate survival analyses.

RESULTS

Median survival from onset was 25 months (interquartile range 16-34 months). In multivariate models we found an increased hazard with more recently diagnosed cases-that is, there was an unexpected decline in survival over the 10 year period (hazard ratio (HR) 1.06 (95% CI 1.04 to 1.09). Positive effects on survival were demonstrated for longer time from onset to diagnosis (HR 0.38 (95% CI 0.33 to 0.42), assessment by a neurological specialist (HR 0.56 (95% CI 0.40 to 0.77), and treatment with riluzole (HR 0.24 (95% CI 0.14 to 0.42). Poor prognosis was associated with bulbar onset (HR 1.25 (95% CI 1.09 to 1.46) and a mixed lower and upper motor neurone syndrome (HR 1.23 (95% CI 1.01-1.49) and increasing age.

CONCLUSIONS

We found an unexpected decline in survival over the 10 year period, despite controlling for potential confounding variables. We would be cautious about over-interpreting these observations and suggest that further research is required to confirm or refute these findings.

Percutaneous radiological gastrostomy: a safe and effective method of nutritional tube placement in advanced ALS

BACKGROUND

Enteral nutrition may be required in amyotrophic lateral sclerosis (ALS), and is usually achieved by percutaneous endoscopic gastrostomy (PEG). As PEG is not indicated in patients with severe respiratory impairment, an alternative is percutaneous radiological gastrostomy (PRG), involving air insufflation into the stomach under fluoroscopic guidance for tube insertion.

OBJECTIVE

To evaluate the safety of PRG and its effect on survival and respiratory function in ALS patients with respiratory failure.

METHODS

25 consecutive ALS patients with severe dysphagia and forced vital capacity (FVC) <50% underwent PRG after October 2000. They were compared with 25 consecutive ALS patients with FVC <50% who underwent PEG before October 2000. Respiratory function was evaluated before and after the procedure.

RESULTS

The two groups were similar for all relevant characteristics. PRG was successful in all cases, PEG in 23/25. One patient in each group died after the procedure. The mean survival time after the procedure was 204 days in the PRG group and 85 days in the PEG group (p<0.004). Respiratory function decreased more in the PEG group than in the PRG group (p<0.02).

CONCLUSIONS

PRG appears to be safer than PEG in ALS patients with moderate or severe respiratory impairment, and is followed by a longer survival.

Occupational exposure to metals and solvents and the risk of motor neuron disease. A case-control study

Previous studies based on recalled occupational histories have implicated metal and solvent exposure in the etiology of motor neuron disease (MND). We have used death certificates held in pension fund archives and linked unbiased historical occupational records to investigate the effects of occupational exposure to metals or solvents on the risk of death from MND in 22 cases and 206 controls from 22,526 past employees of a major UK engineering company. We found no evidence of increased risk of death from MND in individuals who had worked with either metals (adjusted odds ratio=0.88, 95% CI 0.35-2.22) or solvents (odds ratio=1.12, 95% CI 0.45-2.78), and no relation between disease risk and either duration or intensity of exposure. We conclude that metal and solvent exposures are unlikely to be involved in the etiology of MND.

People with motor neurone disease not helped by media

Over the past 18 months, there has been an increased awareness of motor neurone disease (MND) among the public and health professionals. Despite its efforts, the MND Association cannot claim all the credit for this increase. In fact, most of it can be attributed to just two people -- Diane Pretty and Reginald Crew.

Patterns of mortality in patients with motor neurone disease

OBJECTIVE

Motor neurone disease (MND) is a rapidly fatal condition with survival of less than 4 years. Patients can deteriorate quickly in the preterminal stages resulting in inappropriate resuscitation or admission to intensive care units (ICU) or accident and emergency (A & E).

MATERIAL AND METHODS

We looked at patterns of mortality with emphasis on the place of death. A retrospective study was performed of all patients attending an MND clinic, who had died within a 10-year period.

RESULTS

Of 179 patients (63 female), 81 patients (45%) died at home, in a hospice or in a nursing home. Sixty-five patients (36%) died in hospital (11 in ICU or A & E). Nine of the latter were previously known to have MND and six admissions were probably avoidable. Most ward patients died of respiratory causes and were treated conservatively.

CONCLUSION

The proportion of patients dying in A & E or ICU was small but could have been reduced further. A number of those who died on the wards could probably have been managed conservatively at home. Older patients and those with bulbar disease had a poorer prognosis.

[Nocturnal oxymetry in patients with amyotrophic lateral sclerosis: role in predicting survival]

Death is the most important end point along the course of amyotrophic lateral sclerosis (ALS). It is commonly attributed to a respiratory failure in relation with a restrictive respiratory disorder. However, in clinical practice, it is frequent to observe that death has not direct relation with the values of the respiratory function, at least measured with vital capacity. It is also frequent that relatives report sudden death during nocturnal sleep. All these features raised the question of the possible relation between death and nocturnal oxymetry in ALS patients. In a prospective study, we studied 69 ALS patients. We recorded demographic data, clinical parameters as manual muscle testing and functional scales, various parameters of oxymetry measured by pulse oxymetry recorded during night, slow vital capacity and survival time. There is a strong correlation between survival time measured by Kaplan Meier curves and log rank and the mean nocturnal saturation. We determined 93 mmHg as a threshold value. Below this threshold, mean survival time was 7.5+/-1.6 months and above it was equal to 18.5+/-1.5; relative risk was 3.31. These data confirm the importance of nocturnal oxymetry on survival in ALS patients both in clinical practice and in view of therapeutic trials.

Accuracy of death certificates for motor neuron disease and multiple sclerosis in the province of Palermo in southern Italy

Mortality studies based on death certificates (DCs) are relatively inexpensive and easy to conduct. Therefore, they are frequently used to evaluate variations of geographical and temporal patterns, particularly in uncommon diseases. Recent surveys of motor neuron disease (MND) and multiple sclerosis (MS) based on official mortality statistics in Italy showed a decreasing trend of mortality from northern to southern Italy. To evaluate if DCs are homogeneously recorded in Italy and whether or not they can be considered a good instrument for mortality studies, we assessed the accuracy of DCs for MND and MS in the province of Palermo, Italy, and compared our results with those reported in other studies. We searched the archives of the neurological clinic of the University of Palermo for patients affected by one of the two diseases who were residents and were diagnosed in Palermo province. We found 157 patients with definite MND and 360 with clinically definite MS. Seventy-eight out of the 157 MND patients and 43 out of the 360 MS patients had died. Considering the underlying cause of death, the true-positive rate was 48% [95% confidence interval (CI) 36-60%] for MND and 46% (95% Cl 30-62%) for MS. The rates we found for MND were lower than those reported either in Italy or worldwide. This result suggests caution in formulating gradient hypotheses for MND. Concerning MS, the rate we found was low, but similar to that found by others. This indicates that a mortality survey of MS based on DCs is unlikely to be contributory.

Relationship between supramaximal flow during cough and mortality in motor neurone disease

The main function of cough is clearance of intrathoracic airways. A normal cough is characterized by a transient increase in expiratory flow above the maximal flow-volume loop envelope, known as cough "spikes". They may be absent in patients with motor neurone disease. The relationship between cough pattern, pulmonary function and survival was studied. Fifty-three patients were recruited (25 bulbar). Vital capacity, maximal inspiratory and expiratory mouth pressures and cough flow/volume curves were performed on all patients, and the presence or absence of spikes were recorded. The primary endpoints were mortality or initiation of ventilatory support over a period of 18 months. Thirty-five patients died over the 18-month period of the study (including the six who were started on noninvasive ventilation). Twelve of the 24 patients with spikes died compared to 23 out of 29 patients without spikes (p<0.05). Patients without spikes were more likely to be bulbar on clinical grounds (p<0.0001) and had poorer lung function. The results showed an association between the absence of cough spikes and increased mortality. However the main determinants of survival in motor neurone disease are age, vital capacity and inspiratory mouth pressure, and it remains to be shown whether regular monitoring of cough conveys any additional advantage.

A clinical and pathological study of motor neurone disease on Guam

Despite over 40 years of intensive study, the cause of the high incidence of motor neurone disease (MND) on Guam, and the relationship between this disease and MND seen in the rest of the world are still uncertain. We present a series of 45 cases of Guamanian MND, which reaffirm the clinical similarity between this disease and MND seen in other countries. However, the occurrence of MND among the indigenous Chamorros of Guam is distinguished by four factors: (i) high prevalence; (ii) frequent familial occurrence; (iii) co-occurrence with the parkinsonism-dementia complex (PDC); and (iv) association with an unusual and distinctive linear retinopathy termed Guam retinal pigment epitheliopathy (GRPE). These distinguishing factors were not present in four non-Chamorros who resided on Guam when their MND symptoms occurred. Pathologically, the classical features of MND were seen in Guamanian Chamorro cases including ubiquitin inclusions. Neurofibrillary tangles were frequently seen. The neurofibrillary tangles appeared in the same distribution as described in the PDC but, unlike classical PDC, they were not usually associated with cell loss and occurred less frequently. While neurofibrillary tangle formation and the clinicopathological syndrome of MND may occur in parallel, observations from this series suggest that pathologically classical MND on Guam may occur independently of neurofibrillary degeneration and the clinical features of PDC.

[Amyotrophic lateral sclerosis and animal models]

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease which affects cortical, bulbar and spinal motoneurones. The cause of the disease, probably due to several factors, is still unknown and the survival delay of patients with ALS generally does not exceed 3-5 years. Animals models provide a unique opportunity to study pathological features and to evaluate potential therapeutic effects of news treatments. Natural disease models, neurotoxins or viral-induced models and more recently transgenic models with genetic anomalies mimicking those found in ALS patients have been extensively studied. This review summarizes the most relevant clinical and pathological advances issuing from these animal studies.

Incidence and predictors of PEG placement in ALS/MND

In the Project on Death in America ALS cohort, 121 patients were followed to examine the timing of key milestones in the course of the disease, such as tracheostomy and PEG placement. During the 2- to 4-year follow-up period, 26.5% of patients received PEG, yielding a cumulative incidence of 48%. PEG placement occurred, on average, 16 months after patients received confirmation of the diagnosis at our Center. Patients who received PEG were more likely to have tracheostomies than patients not using PEG (p<0.01). In multivariate proportional hazard models that included both sociodemographic and disease indicators, the strongest predictor of PEG use was a patient's baseline preference for PEG: 57.1% of patients "absolutely in favor" went on to have PEG, compared to only 9.3% of those "absolutely against" (p<0.01). PEG users were more likely to have initiated health care proxies. These findings suggest that patients who use PEG may be consistently proactive in the face of the disease.

Disease status and use of ventilatory support by ALS patients. BDNF Study Group

INTRODUCTION

Use of mechanical ventilation (MV), administered either invasively via tracheostomy, or more commonly non-invasively (CPAP, BiPAP), appears to be increasing in ALS. No prospective databases exist that describe the behavior of physicians and patients and the criteria for instituting MV in ALS.

METHODS

387 placebo patients in a Phase III trial of r-metHuBDNF were followed for 9 months. Although the use of MV was not the primary end-point of the trial, information was gathered regarding it by cataloging respiratory adverse events and tracking health resource utilization.

RESULTS

35 of 387 patients utilized MV during the trial. Twenty-eight (7%) patients received BiPAP. Seven (2%) were tracheotomized without first receiving BiPAP. Forced vital capacity (FVC): BiPAP patients had a mean ( SEM) FVC% of 71.8 +/- 2.8% and ALSFRS of 27.7 +/- 1.0 at baseline; non-BiPAP patients had a mean baseline FVC% of 88.7 +/- 1.0%, and an ALSFRS of 30.3 +/- 0.3. Symptom duration at entry was similar for both groups (2.1 +/- 0.4 years vs. 2.1 +/- 0.1 years). At the time of first use of BiPAP, average FVC% was 47.5 +/- 4.0% and ALSFRS score was 22.4 +/- 1.5. The range of FVC% at start of BiPAP was 15-87. The nine-month survival was 67.9% for BiPAP patients vs. 86% for non-BiPAP patients. The use of BiPAP varied tremendously among the 38 study sites, with some not employing it at all and others using it in as many as 40% of patients.

CONCLUSIONS

Of the 9% of placebo patients who received MV, BiPAP patients were more rapidly progressing than non-BIPAP patients, and showed a greater eventual mortality rate. Patients began MV at a wide range of values of FVC%, and centers differed in their prescribing practices. Factors influencing BiPAP use are complex, and not strictly related to FVC%.

Examining the evidence about treatment in ALS/MND

The application of evidence-based medicine to the treatment of patients with amyotrophic lateral sclerosis (ALS) is just beginning. A small number of systematic reviews analyzing the pertinent evidence, grading the methodology and formulating recommendations to guide clinical decision-making have begun to appear. The American Academy of Neurology practice parameters for informing the patient and managing nutritional and respiratory issues and palliative care are discussed. In addition, the first systematic review in the field of ALS/MND from the Cochrane collaboration concerns riluzole treatment and this meta-analysis is also described. Some of the most important recommendations that have the potential to significantly prolong survival and enhance quality of life are the early institution of percutaneous endoscopic gastrostomy for patients with significant dysphagia, and the initiation of non-invasive positive pressure ventilation for patients with symptoms of early respiratory insufficiency. Assertive treatment of pain and dyspnea are also strongly recommended for patients with ALS. The North American ALS patient database, ALS C.A.R.E., is also described as a methodology for measuring clinical outcomes, and some early results are presented. The evidence on riluzole indicates effectiveness in prolonging survival with a good safety profile.

An orally active anti-apoptotic molecule (CGP 3466B) preserves mitochondria and enhances survival in an animal model of motoneuron disease

Apoptosis and mitochondrial dysfunction are thought to be involved in the aetiology of neurodegenerative diseases. We have tested an orally active anti-apoptotic molecule (CGP 3466B) that binds to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in an animal model with motoneuron degeneration, i.e. a mouse mutant with progressive motor neuronopathy (pmn). In pmn/pmn mice, CGP 3466B was administered orally (10 - 100 nmol kg(-1)) at the onset of the clinical symptoms (2 weeks after birth). CGP 3466B slowed disease progression as determined by a 57% increase in life-span, preservation of body weight and motor performance. This improvement was accompanied by a decreased loss of motoneurons and motoneuron fibres as well as an increase in retrograde transport. Electron microscopic analysis showed that CGP 3466B protects mitochondria which appear to be selectively disrupted in the motoneurons of pmn/pmn mice. The data support evaluation of CGP 3466B as a potential treatment for motor neuron disease.

Phenotypic differences between African and white patients with motor neuron disease: a case-control study

There is increasing evidence that race may affect the phenotype in some neurodegenerative diseases. To investigate this in motor neuron disease a retrospective case-control study has been carried out on 15 negroid African and 45 white patients with the disease seen over 8 years. Each African was compared with three age and sex matched white patients with motor neuron disease. There were no statistically significant differences in age of onset or the mean duration of disease in the two groups. The chance of presenting with the "flail arm" variant of motor neuron disease was four times as high in the African group than the white group (odds ratio 4.33, p=0. 05, 95% confidence interval 0.99-18.92). Although no overall differences in survival were seen between the two groups, in those with the flail arm variant, four out of the six African patients had died whereas all six white arm patients were alive at the censoring date of 1 January 1999 (median follow up 38.5 months). It is concluded that race may influence the phenotype and progression of motor neuron disease.

Sleep disorders and diaphragmatic function in patients with amyotrophic lateral sclerosis

In amyotrophic lateral sclerosis (ALS), the progressive loss of upper and lower motor neurons leads to respiratory failure, often with predominant diaphragm dysfunction, and death. Because the diaphragm is the only active inspiratory muscle during rapid eye movement (REM) sleep, there is a high theoretical risk of respiratory disorders during REM sleep in patients with ALS. To assess this hypothesis, we studied sleep characteristics (polysomnography) in 21 patients with ALS, stratified according to the presence or absence of diaphragmatic dysfunction. Diaphragmatic dysfunction was defined as an absent or delayed diaphragm response to cervical or cortical magnetic stimulation, abdominal paradox, or respiratory pulse (Group 1, 13 patients). These patients did not differ in age, clinical course, or form (bulbar or spinal) from the eight others, who did not have diaphragmatic dysfunction (Group 2). REM sleep was reduced in Group 1 (7 +/- 7% of total sleep time; mean +/- SD) and normal in Group 2 (18 +/- 6%, p = 0.004). Apneas or hypopneas were rare in both groups. In Group 1, REM sleep was absent or minimal (less than 3 min) in five patients. An unusual and remarkable preservation of phasic inspiratory sternomastoid activation during REM was associated with longer REM sleep duration in six of the other patients with diaphragmatic dysfunction. Median survival time was dramatically shorter (217 d) in Group 1 than in Group 2 (619 d, p = 0.015).

[Analysis of the cohort effect on the trend in mortality from motor neuron disease in Spain, 19551-1002]

BACKGROUND

An increase in the mortality due to motor neuron disease (MND) has been reported in Spain over the past 30-40 years. It has been suggested that this increase is due to the cohort effect, but his hypothesis has not been proven.

METHODS

The motor neuron disease (MND) mortality statistics by age and by gender were furnished from the Spanish National Institute of Statistics. The mortality specifically by age and the adjusted age-related rates were calculated. By Poisson regression, the cohort effect of birth on the mortality by ages has been analyzed, the cohort effect also having been analyzed by graphic methods.

RESULTS

The mortality adjusted by age was declining up until 1969, as of which time it has been on the rise. Each five-year birth cohort increases the risk of dying from MND by 8.5%.

CONCLUSIONS

The increase in the mortality due to MND in Spain is the result of a cohort effect.

The management of patients with advanced motor neuron disease

BACKGROUND

There is no specific treatment for motor neuron disease (MND) except hospice or palliative care to improve patients' quality of life and decrease complications. This topic is seldom discussed in Taiwan.

METHODS

A retrospective study was conducted of patients with terminal MND who were treated and died at the Veterans General Hospital-Taipei from March 1986 through April 1996. Patients' characteristics, management, length of survival and cause of death were analyzed.

RESULTS

Twenty-three patients (M/F, 17/6) were included. The median age of onset was 59 years (range, 24-69). The median interval from onset of symptoms to diagnosis was nine months (range, 2-36). Seventeen patients received mechanical ventilation for an average median of six months. Nineteen patients had dysphagia, 17 received long-term nasogastric tube feeding, one had gastrostomy and one was treated with cricopharyngeal myotomy. Pain over the neck, trunk or limbs was reported by 18 patients; none received narcotics. Only two patients received respiratory exercise training and two had a cervical collar for stabilization. Electronic communication aids were not available. The median survival from onset of symptoms was 36 months (range, 7-99). The causes of death included sepsis (n = 13), respiratory failure (n = 7), heart disease (n = 2) and MND-related cachexia (n = 1). Cardiopulmonary resuscitation was performed for 12 patients.

CONCLUSIONS

In Taiwan, management of patients with advanced MND is mainly hospital-based and most of the effort is focused on life-sustaining. More attention needs to be paid to improvement of the quality of life and dignity of the patient.

Differential features of motor neuron disease mortality in Spain

BACKGROUND

The objective of this study was to describe the temporal and spatial patterns of motor neuron disease (MND) in Spain.

METHODS

We studied data where MND was stated as the principal cause of death in official statistics from Spain. Time trends were analysed for age-, sex-specific and age-adjusted rates for the period 1951-1990. Age-adjusted mortality and relative risk, obtained by Poisson regression adjusting for age, were calculated for each province from deaths during the period 1975-1988. Maps were constructed using log transformed rates. Statistical significance of spatial aggregation was assessed using the Ohno et al. test.

RESULTS

The 1951-1990 mortality rate, age- and sex-adjusted to the European population, for the population aged > or = 40 years was 1.49 per 100,000; 1.90 and 1.21 for males and females respectively. In general, mortality increased with age. Age-adjusted rates rose until 1960, dropped by 70% during the 1960s and declined slightly over the 1951-1990 period as a whole. From 1970 onwards MND mortality rose evenly, particularly in the 60-69 age group. A North-South gradient was suggested for both sexes with statistically significant clustering in the Northern coastal regions and--for males alone--in the Midwest provinces.

CONCLUSIONS

Mortality from MND in Spain displayed a magnitude and recently rising temporal trend similar to that described in several other countries. Specific traits were: a decrease during the 1960s, which has been described for Japan only, as well as spatial heterogeneity and a predominant recent increase among the 60-69 age group. The determinants of these unusual MND mortality patterns are unknown.

Gene therapy of murine motor neuron disease using adenoviral vectors for neurotrophic factors

Motor neuron diseases such as amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy cause progressive paralysis, often leading to premature death. Neurotrophic factors have been suggested as therapeutic agents for motor neuron diseases, but their clinical use as injected recombinant protein was limited by toxicity and/or poor bioavailability. We demonstrate here that adenovirus-mediated gene transfer of neurotrophin-3 (NT-3) can produce substantial therapeutic effects in the mouse mutant pmn (progressive motor neuronopathy). After intramuscular injection of the NT-3 adenoviral vector, pmn mice showed a 50% increase in life span, reduced loss of motor axons and improved neuromuscular function as assessed by electromyography. These results were further improved by coinjecting an adenoviral vector coding for ciliary neurotrophic factor. Therefore, adenovirus-mediated gene transfer of neurotrophic factors offers new prospects for the treatment of motor neuron diseases.

Protective effect of a novel free radical scavenger, OPC-14117, on wobbler mouse motor neuron disease

A possible protective effect of a novel free radical scavenger, OPC-14117, on the progressive motor neuron death in wobbler mice was examined. Clinical parameters such as mortality, body weight, motor activity as a rolling number of circular cage, and forelimb muscle power as grasping on a rolling column, an angle of slipping down from slope, and hanging ability on a flat plate were compared every 4 weeks from 4 to 36 weeks of age among mice groups treated with vehicle or daily oral administration of OPC-14117 of 10 or 30 mg/kg body weight. The treatment with OPC-14117 dose dependently improved the clinical parameters such as mortality, motor activity, and forelimb weakness. Pathological analysis showed that a diffuse neurogenic change in the forelimb muscle was improved at 36 weeks of age in the drug treated mice with a marked preservation of motor neurons in the spinal cord. Treatment of the mice with the drug reduced age-dependent increase of lipid peroxides in the spinal cord in vivo, and a supplement of the drug to the homogenate of spinal cord in vitro ameliorated the formations of lipid peroxides generated by an exogenous addition of ascorbate or xanthine/xanthine oxidase. These results suggest that OPC-14117 has a protective effect on the motor neuron death probably as a free radical scavenger, resulting in an improvement of clinical symptoms in wobbler mice.

Riluzole. A review of its pharmacodynamic and pharmacokinetic properties and therapeutic potential in amyotrophic lateral sclerosis

Riluzole, a benzothiazole, affects neurons by 3 mechanisms: by inhibiting excitatory amino acid release, inhibiting events following stimulation of excitatory amino acid receptors and stabilising the inactivated state of voltage-dependent sodium channels. It has demonstrated neuroprotective activity in vivo and in vitro. Results from 2 randomised double-blind placebo-controlled trials in patients with amyotrophic lateral sclerosis (ALS; motor neuron disease) have demonstrated that riluzole can extend survival and/or time to tracheostomy. After 18 months, the relative risk of death or tracheostomy with riluzole 100 mg/day was reduced by 21%. Although riluzole slowed the rate of deterioration in muscle strength in the first trial, this was not confirmed in the second, larger trial. Riluzole had no effect on any other functional or secondary variable. Gastrointestinal effects, anorexia, asthenia, circumoral paraesthesia and dizziness were reported more frequently with riluzole than placebo. Elevated alanine aminotransferase levels were observed in 10.6 versus 3.8% of patients treated with riluzole 100 mg/day versus placebo, leading to treatment withdrawal in 3.8 versus 2.1% of patients. In conclusion, riluzole is the first drug that has been shown to have an effect on survival in patients with ALS. Although the effect of riluzole was modest, it has allowed some insight into the pathogenesis of ALS from which future gains may be made.

Neurodegenerative diseases: occupational occurrence and potential risk factors, 1982 through 1991

OBJECTIVES

To identify potential occupational risk factors, this study examined the occupational occurrence of various neurodegenerative diseases.

METHODS

Death certificates from 27 states in the National Occupational Mortality Surveillance System were evaluated for 1982 to 1991. Proportionate mortality ratios were calculated by occupation for presenile dementia, Alzheimer's disease, Parkinson's disease, and motor neuron disease.

RESULTS

Excess mortality was observed for all four categories in the following occupational categories: teachers; medical personnel; machinists and machine operators; scientists; writers/designers/entertainers; and support and clerical workers. Clusters of three neurodegenerative diseases were also found in occupations involving pesticides, solvents, and electromagnetic fields and in legal, library, social, and religious work. Early death from motor neuron disease was found for firefighters, janitors, military personnel, teachers, excavation machine operators, and veterinarians, among others.

CONCLUSIONS

Neurodegenerative disease occurs more frequently in some occupations than in others, and this distribution, which may indicate occupational risk factors, should be further investigated.