Duration of amyotrophic lateral sclerosis is age dependent

Differential cortical gray matter changes in early- and late-onset patients with amyotrophic lateral sclerosis

Age at onset may be an important feature associated with distinct subtypes of amyotrophic lateral sclerosis (ALS). Little is known about the neuropathological mechanism of early-onset ALS (EO-ALS) and late-onset ALS (LO-ALS). Ninety ALS patients were divided into EO-ALS and LO-ALS group, and 128 healthy controls were matched into young controls(YCs) and old controls (OCs). A voxel-based morphometry approach was employed to investigate differences in gray matter volume (GMV). Significant age at onset-by-diagnosis interactions were found in the left parietal operculum, left precentral gyrus, bilateral postcentral gyrus, right occipital gyrus, and right orbitofrontal cortex. Post hoc analysis revealed a significant decrease in GMV in all affected regions of EO-ALS patients compared with YCs, with increased GMV in 5 of the 6 brain regions, except for the right orbitofrontal cortex, in LO-ALS patients compared with OCs. LO-ALS patients had a significantly increased GMV than EO-ALS patients after removing the aging effect. Correspondingly, GMV of the left postcentral gyrus correlated with disease severity in the 2 ALS groups. Our findings suggested that the pathological mechanisms in ALS patients with different ages at onset might differ. These findings provide unique insight into the clinical and biological heterogeneity of the 2 ALS subtypes.

Case Report: Cognitive Conversion in a Non-brazilian VAPB Mutation Carrier (ALS8)

Amyotrophic lateral sclerosis 8 (ALS8) is a predominantly lower motor neuron syndrome originally described in a Portuguese–Brazilian family, which originated from a common founder. ALS8 is caused by a VAPB mutation and extremely rare in Central Europe. We present a 51-year-old German man with ALS8 who had the P56S VAPB mutation independently of the founder effect. In the final 4 years of his life (disease duration 10 years), the patient had five MRI scans and four in-depth neuropsychological assessments. This paper addresses the course of the patient's cognitive status and relates cognitive performance to structural brain changes in order to determine whether this ALS8 case showed a different pattern of cognitive decline compared with sporadic ALS. The executive functions, verbal fluency, and memory of the patient and 17 age-, sex-, and education-matched controls were assessed on four different occasions. His cognitive performance and decline were investigated for abnormality using cross-sectional and longitudinal matched case–control analysis. We obtained five T1-weighted MRI, which we analyzed using voxel-wise non-parametric analysis with statistical non-parametric mapping in Matlab. Moreover, we conducted a single-subject correlation between cognitive performance and brain atrophy. The cognitive profile of the index patient featured executive dysfunction. Notably, his working memory and shifting ability declined from a healthy baseline to an impaired performance, leading to a transition from cognitively non-impaired (ALSni) to cognitively impaired (ALSci). The correlations we observed between cerebellar atrophy and verbal fluency in addition to fusiform gyrus atrophy and shifting are novel findings. We found that the conversion from ALSni to ALSci was associated with widespread cerebral atrophy, which extended beyond the primary motor and premotor cortex and affected, among others, the cerebellum and left fusiform gyrus. The index patients' cognitive profile resembles that of other ALS phenotypes, but the extensive atrophy beyond extra-motor areas has not yet been described.

Cognitive network hyperactivation and motor cortex decline correlate with ALS prognosis

We aimed to quantitatively characterize progressive brain network disruption in Amyotrophic Lateral Sclerosis (ALS) during cognition using the mismatch negativity (MMN), an electrophysiological index of attention switching. We measured the MMN using 128-channel EEG longitudinally (2-5 timepoints) in 60 ALS patients and cross-sectionally in 62 healthy controls. Using dipole fitting and linearly constrained minimum variance beamforming we investigated cortical source activity changes over time. In ALS, the inferior frontal gyri (IFG) show significantly lower baseline activity compared to controls. The right IFG and both superior temporal gyri (STG) become progressively hyperactive longitudinally. By contrast, the left motor and dorsolateral prefrontal cortices are initially hyperactive, declining progressively. Baseline motor hyperactivity correlates with cognitive disinhibition, and lower baseline IFG activities correlate with motor decline rate, while left dorsolateral prefrontal activity predicted cognitive and behavioural impairment. Shorter survival correlates with reduced baseline IFG and STG activity and later STG hyperactivation. Source-resolved EEG facilitates quantitative characterization of symptom-associated and symptom-preceding motor and cognitive-behavioral cortical network decline in ALS.

Neuropathological profile of long-duration amyotrophic lateral sclerosis in military Veterans

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder affecting both the upper and lower motor neurons. Although ALS typically leads to death within 3 to 5 years after initial symptom onset, approximately 10% of patients with ALS live more than 10 years after symptom onset. We set out to determine similarities and differences in clinical presentation and neuropathology in persons with ALS with long vs. those with standard duration. Participants were United States military Veterans with a pathologically confirmed diagnosis of ALS (n = 179), dichotomized into standard duration (<10 years) and long-duration (≥10 years). The ALS Functional Rating Scale-Revised (ALSFRS-R) was administered at study entry and semi-annually thereafter until death. Microglial density was determined in a subset of participants. long-duration ALS occurred in 76 participants (42%) with a mean disease duration of 16.3 years (min/max = 10.1/42.2). Participants with long-duration ALS were younger at disease onset (P = 0.002), had a slower initial ALS symptom progression on the ALSFRS-R (P < 0.001) and took longer to diagnose (P < 0.002) than standard duration ALS. Pathologically, long-duration ALS was associated with less frequent TDP-43 pathology (P < 0.001). Upper motor neuron degeneration was similar; however, long-duration ALS participants had less severe lower motor neuron degeneration at death (P < 0.001). In addition, the density of microglia was decreased in the corticospinal tract (P = 0.017) and spinal cord anterior horn (P = 0.009) in long-duration ALS. Notably, many neuropathological markers of ALS were similar between the standard and long-duration groups and there was no difference in the frequency of known ALS genetic mutations. These findings suggest that the lower motor neuron system is relatively spared in long-duration ALS and that pathological progression is likely slowed by as yet unknown genetic and environmental modifiers.

Can Proprioceptive Training Reduce Muscle Fatigue in Patients With Motor Neuron Diseases? A New Direction of Treatment

Muscle fatigue is a serious problem in patients with motor neuron diseases (MNDs). It commonly disturbs both daily life activity and rehabilitation tolerance. A particular concern should be taken when MNDs occur in older ages. Older patients with MNDs usually have a worse clinical presentation and a lower survival rate. This could increase the occurrence of muscle fatigue. Muscle fatigue occurs due to a dysfunction in either motor or sensory systems. Current exercise interventions performed to decrease the occurrence of muscle fatigue focused only on treating motor causes of muscle fatigue. It has been demonstrated that these interventions have a high debate in their effectiveness on decreasing the occurrence of muscle fatigue. Also, these exercise interventions ignored training the affected sensory part of muscle fatigue, however, the important role of the sensory system in driving the motor system. Thus, this review aimed to develop a novel exercise intervention by using proprioceptive training as an intervention to decrease the occurrence of muscle fatigue in patients with MNDs particularly, older ones. The physiological effects of proprioceptive training to decrease the occurrence of muscle fatigue could include two effects. The first effect includes the ability of the proprioceptive training to increase the sensitivity of muscle spindles as an attempt to normalize the firing rate of α-motoneurons, which their abnormalities have major roles in the occurrence of muscle fatigue. The second effect includes its ability to correct the abnormal movement-compensations, which develop due to the biomechanical constraints imposed on patients with MNDs.

Late age onset of amyotrophic lateral sclerosis is often not considered in elderly people

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease causing an upper and lower motor neuron loss. It is neurology textbook knowledge that the mean age of onset is about 60 years. However, recent investigations show an increasing incidence in older persons. We therefore evaluated whether ALS is potentially not considered in elderly people with ALS symptoms, respectively, not recognized.

MATERIALS AND METHODS

We included retrospectively all patients with ALS diagnoses after work-up that were admitted to our neurological and geriatric departments from 2007 to 2010 and collected their clinical data. The diagnosis of ALS was based on the El Escorial criteria. Patients were grouped into three categories according to age (<50, between 50 and 70, >70), and differences in clinical and/ or biographical factors were investigated.

RESULTS

We identified 35 patients (18 men and 17 women) with a median age at onset of 71.5 years (range: 36-87 years). When establishing the diagnosis, 51% were older than 70 years, 40% (14/35) between 50 and 70, and only 9% younger than 50. Only in 46 per cent of patients who were sent to our departments with ALS symptoms ALS was considered by the referring physician.

CONCLUSION

Late age onset of ALS seems to be more common than formerly assumed and is presumably under-recognized in elderly patients. ALS needs to be considered as a differential diagnosis in older patients. Potential factors accounting for older people being underdiagnosed with ALS relate to frequent presentation with symptoms like dysphagia, frailty or general weakness for other reasons.

Complete hazard ranking to analyze right-censored data: An ALS survival study

Survival analysis represents an important outcome measure in clinical research and clinical trials; further, survival ranking may offer additional advantages in clinical trials. In this study, we developed GuanRank, a non-parametric ranking-based technique to transform patients' survival data into a linear space of hazard ranks. The transformation enables the utilization of machine learning base-learners including Gaussian process regression, Lasso, and random forest on survival data. The method was submitted to the DREAM Amyotrophic Lateral Sclerosis (ALS) Stratification Challenge. Ranked first place, the model gave more accurate ranking predictions on the PRO-ACT ALS dataset in comparison to Cox proportional hazard model. By utilizing right-censored data in its training process, the method demonstrated its state-of-the-art predictive power in ALS survival ranking. Its feature selection identified multiple important factors, some of which conflicts with previous studies.

Survey of cannabis use in patients with amyotrophic lateral sclerosis

Cannabis (marijuana) has been proposed as treatment for a widening spectrum of medical conditions and has many properties that may be applicable to the management of amyotrophic lateral sclerosis (ALS). This study is the first, anonymous survey of persons with ALS regarding the use of cannabis. There were 131 respondents, 13 of whom reported using cannabis in the last 12 months. Although the small number of people with ALS that reported using cannabis limits the interpretation of the survey findings, the results indicate that cannabis may be moderately effective at reducing symptoms of appetite loss, depression, pain, spasticity, and drooling. Cannabis was reported ineffective in reducing difficulties with speech and swallowing, and sexual dysfunction. The longest relief was reported for depression (approximately two to three hours).

Prognostic factors and survival of ALS patients from Belgrade, Serbia

Our aim was to assess the incidence, survival and its prognostic factors in ALS patients from the area of the City of Belgrade, Serbia. A retrospective analysis included 325 probable or definite ALS cases from all five Belgrade neurology departments in the period 1992-2009. Each patient was regularly followed up during the disease until death or until 31 December 2009. Results showed that the average annual ALS incidence rate was 1.11 per 100,000 inhabitants. Male predominance was registered, except for patients with ALS onset after the age of 80 years. Mean survival from the first symptoms was 4.4 ± 0.2 years. Cumulative probability of survival was 71% for two years, 24% for five years, and 17% for seven years. Patients with diagnostic delay longer than 1.6 years had a 1.4-times better chance for survival (p <0.01). Spinal-onset patients on riluzole therapy had 1.8-times better survival (p < 0.01). Patients with early-onset ALS and higher ALSFRS-R score at initial evaluation also had somewhat better survival (p < 0.05). In conclusion, the average annual ALS incidence rate was 1.11 per 100,000 inhabitants. Longer survival was observed in patients with early onset, longer diagnostic delay, less functional impairment at the time of diagnosis, and riluzole treatment.

Anti-Glutamate Therapy in Amyotrophic Lateral Sclerosis: A Trial Using Lamotrigine

Glutamate excitotoxicity is implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). We report the results of a double blind, placebo controlled, trial using 100 mg of oral daily lamotrigine (3,5-diamino-6-(2,3 dichlorophenyl)-l,2,4-triazine) which inhibits glutamate release. 67 patients were entered and at trial termination of 1.5 years 15 had withdrawn (9 active and 6 placebo) and 12 had died (6 active and 6 placebo). Mean age at entry was 57.5 years for the active and 58.6 years for the placebo groups. Patients were seen at 3 monthly intervals and scored according to neurological deficit based upon age of onset, bulbar and respiratory involvement, ambulation and functional disability. The mean change in clinical scores for the active versus placebo groups over the trial period was 7.1 ± 3.3 and 9.0 ± 3.3 respectively (0.05 < p < 0.10). Changes in cortical threshold and MEP/CMAP ratios to magnetic stimulation also did not differ significantly between the two groups. We conclude that lamotrigine in the doses administered does not alter the course of ALS.

Motor and extra-motor gray matter atrophy in amyotrophic lateral sclerosis: quantitative meta-analyses of voxel-based morphometry studies

Considerable evidence from previous voxel-based morphometry studies indicates widespread but heterogeneous gray matter (GM) deficits in amyotrophic lateral sclerosis (ALS). Here, we aimed to investigate the concurrence across voxel-based morphometry studies to help clarify the spatial pattern of GM abnormalities that underlie this condition. Comprehensive meta-analyses to assess regional GM anomalies in ALS were conducted with the Anisotropic Effect Size version of Signed Differential Mapping software package. Twenty studies, which reported 22 comparisons and were composed of 454 ALS patients and 426 healthy controls, were included in the meta-analyses. Regional GM atrophy in ALS was consistently found in the frontal, temporal, and somatosensory areas. Meta-regression demonstrated that the disease duration, disease severity, and age were significantly related to GM deficits in ALS patients. The present meta-analysis provides convergent evidence that ALS is a multisystem degenerative disorder that is accompanied by a unique and widespread pattern of robust cortical GM atrophy. Future studies should investigate whether this atrophy pattern is a diagnostic and prognostic marker.

The predictors of survival in Chinese amyotrophic lateral sclerosis patients

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disease, so it is important to explore the survival factors for ALS. Our aim was to evaluate the predictors of survival in Chinese ALS patients. A total of 1049 sporadic ALS patients were enrolled. Kaplan-Meier curves were used to compare survival time. Cox proportional hazards function and the hazard ratio were used to identify adjusted prognostic predictors. Results showed that the mean age of onset was 52.6 ± 12.0 years. During follow-up, 155 patients (14.8%) were lost and 378 patients were deceased. Median survival was 33 months for the deceased patients. In the adjusted Cox proportional hazard model, age of onset, diagnosis delay, rate of disease progression, and non-invasive positive pressure ventilation (NIPPV) treatment had an effect on survival in ALS. In conclusion, our study provides information on survival factors for Chinese ALS patients. Although the onset age of Chinese ALS patients is earlier than that of Caucasian patients, survival factors, including the age of onset, diagnostic delay, rate of disease progression, and NIPPV treatment, are similar.

The eye-tracking computer device for communication in amyotrophic lateral sclerosis

OBJECTIVE

To explore the effectiveness of communication and the variables affecting the eye-tracking computer system (ETCS) utilization in patients with late-stage amyotrophic lateral sclerosis (ALS).

METHODS

We performed a telephone survey on 30 patients with advanced non-demented ALS that were provisioned an ECTS device. Median age at interview was 55 years (IQR = 48-62), with a relatively high education (13 years, IQR = 8-13). A one-off interview was made and answers were later provided with the help of the caregiver. The interview included items about demographic and clinical variables affecting the daily ETCS utilization.

RESULTS

The median time of ETCS device possession was 15 months (IQR = 9-20). The actual daily utilization was 300 min (IQR = 100-720), mainly for the communication with relatives/caregiver, internet surfing, e-mailing, and social networking. 23.3% of patients with ALS (n = 7) had a low daily ETCS utilization; most reported causes were eye-gaze tiredness and oculomotor dysfunction.

CONCLUSIONS

Eye-tracking computer system is a valuable device for AAC in patients with ALS, and it can be operated with a good performance. The development of oculomotor impairment may limit its functional use.

Age at onset of amyotrophic lateral sclerosis in China

BACKGROUND

For patients with amyotrophic lateral sclerosis (ALS), age at onset is not only a key factor for diagnosis and prognosis, but also a clue for exploring pathogenesis. Reports based on results from a single medical center suggested that the mean age at onset of ALS in China was earlier than in other developed countries. A larger, multicenter-based study is needed to confirm this finding.

METHODS

A registry-based study of ALS was conducted at 10 ALS centers of the Chinese ALS Association from March 1, 2009 to August 31, 2009. The demographical and clinical features of patients with ALS were collected.

RESULTS

Data from a total of 455 patients with ALS were available for analysis. The mean age at onset for the entire cohort was 52.4 ± 12.1 years. The peak age at onset was in the 45- to 49-year-old age group for women and the 55- to 59-year-old age group for men. The age at onset for patients from Guangzhou (a southern region) was significantly earlier than it was for patients from Shanghai (an eastern region) (t = 2.270, P = 0.025).

CONCLUSIONS

This investigation confirmed the earlier age at onset of ALS in China as compared with other countries. Further population-based case-control investigations of genetic and environmental factors are needed to identify the potential risk factors for Chinese ALS patients.

Multimodal MRI as a diagnostic biomarker for amyotrophic lateral sclerosis

OBJECTIVE

Reliable biomarkers for amyotrophic lateral sclerosis (ALS) are needed, given the clinical heterogeneity of the disease. Here, we provide proof-of-concept for using multimodal magnetic resonance imaging (MRI) as a diagnostic biomarker for ALS. Specifically, we evaluated the added diagnostic utility of proton magnetic resonance spectroscopy (MRS) to diffusion tensor imaging (DTI).

METHODS

Twenty-nine patients with ALS and 30 age- and gender-matched healthy controls underwent brain MRI which used proton MRS including spectral editing techniques to measure γ-aminobutyric acid (GABA) and DTI to measure fractional anisotropy of the corticospinal tract. Data were analyzed using logistic regression, t-tests, and generalized linear models with leave-one-out analysis to generate and compare the resulting receiver operating characteristic (ROC) curves.

RESULTS

The diagnostic accuracy is significantly improved when the MRS data were combined with the DTI data as compared to the DTI data only (area under the ROC curves (AUC) = 0.93 vs. AUC = 0.81; P = 0.05). The combined MRS and DTI data resulted in sensitivity of 0.93, specificity of 0.85, positive likelihood ratio of 6.20, and negative likelihood ratio of 0.08 whereas the DTI data only resulted in sensitivity of 0.86, specificity of 0.70, positive likelihood ratio of 2.87, and negative likelihood ratio of 0.20.

INTERPRETATION

Combining multiple advanced neuroimaging modalities significantly improves disease discrimination between ALS patients and healthy controls. These results provide an important step toward advancing a multimodal MRI approach along the diagnostic test development pathway for ALS.

An imbalance between excitatory and inhibitory neurotransmitters in amyotrophic lateral sclerosis revealed by use of 3-T proton magnetic resonance spectroscopy

IMPORTANCE

A lack of neuroinhibitory function may result in unopposed excitotoxic neuronal damage in amyotrophic lateral sclerosis (ALS).

OBJECTIVE

To determine whether there are reductions in γ-aminobutyric acid (GABA) levels and elevations in glutamate-glutamine (Glx) levels in selected brain regions of patients with ALS by use of proton magnetic resonance spectroscopy.

DESIGN

Case-control study using short echo time and GABA-edited proton magnetic resonance spectroscopy at 3 T with regions of interest in the left motor cortex, left subcortical white matter, and pons; data analyzed using logistic regression, t tests, and Pearson correlations; and post hoc analyses performed to investigate differences between riluzole-naive and riluzole-treated patients with ALS.

SETTING

Tertiary referral center.

PARTICIPANTS

Twenty-nine patients with ALS and 30 age- and sex-matched healthy controls.

EXPOSURE

Fifteen patients were taking 50 mg of riluzole twice a day as part of their routine clinical care for ALS.

MAIN OUTCOMES AND MEASURES

Levels of GABA, Glx, choline (a marker of cell membrane turnover), creatine (a marker of energy metabolism), myo-inositol (a marker of glial cells), and N-acetylaspartate (a marker of neuronal integrity).

RESULTS

Patients with ALS had significantly lower levels of GABA in the motor cortex than did healthy controls (P < .01). Patients with ALS also had significantly lower levels of N-acetylaspartate in the motor cortex (P < .01), subcortical white matter (P < .05), and pons (P < .01) and higher levels of myo-inositol in the motor cortex (P < .001) and subcortical white matter (P < .01) than did healthy controls. Riluzole-naive patients with ALS had higher levels of Glx than did riluzole-treated patients with ALS (P < .05 for pons and motor cortex) and healthy controls (P < .05 for pons and motor cortex). Riluzole-naive patients with ALS had higher levels of creatine in the motor cortex (P < .001 for both comparisons) and subcortical white matter (P ≤ .05 for both comparisons) than did riluzole-treated patients with ALS and healthy controls. Riluzole-naive patients with ALS had higher levels of N-acetylaspartate in the motor cortex than did riluzole-treated patients with ALS (P < .01).

CONCLUSIONS AND RELEVANCE

There are reduced levels of GABA in the motor cortex of patients with ALS. There are elevated levels of Glx in riluzole-naive patients with ALS compared with riluzole-treated patients with ALS and healthy controls. These results point to an imbalance between excitatory and inhibitory neurotransmitters as being important in the pathogenesis of ALS and an antiglutamatergic basis for the effects of riluzole, although additional research efforts are needed.

Epidemiological survey-based formulae to approximate incidence and prevalence of neurological disorders in the United States: a meta-analysis

Background

This study aims to create a convenient reference for both clinicians and researchers so that vis-à-vis comparisons between brain disorders can be made quickly and accurately. We report here the incidence and prevalence of the major adult-onset brain disorders in the United States using a meta-analysis approach.

Material and Methods

Epidemiological figures were collected from the most recent, reliable data available in the research literature. Population statistics were based on the most recent census from the US Census Bureau. Extrapolations were made only when necessary. The most current epidemiological studies for each disorder were chosen. All effort was made to use studies based on national cohorts. Studies reviewed were conducted between 1950 and 2009. The data of the leading studies for several neurological studies was compiled in order to obtain the most accurate extrapolations. Results were compared to commonly accepted values in order to evaluate validity.

Results

It was found that 6.75% of the American adult population is afflicted with brain disorders. This number was eclipsed by the 8.02% of Floridians with brain disorders, which is due to the large aged population residing in the state.

Conclusions

There was a noticeable lack of epidemiological data concerning adult-onset brain disorders. Since approximately 1 out of every 7 households is affected by brain disorders, increased research into this arena is warranted.

The Department of Veterans Affairs Biorepository Brain Bank: a national resource for amyotrophic lateral sclerosis research

Our objective was to describe a unique national resource to facilitate amyotrophic lateral sclerosis (ALS) research, the Department of Veterans Affairs Biorepository Brain Bank. Enrolled veterans receive biannual telephone follow-up to collect clinical data until death including the ALS Functional Rating Scale-Revised (ALSFRS-R). A comprehensive post mortem examination is performed and a wide range of fixed and frozen brain and spinal cord samples are banked. As of December 2012, 240 veterans were enrolled from 47 states and post mortem tissue recoveries were performed on 100 veterans from 37 states. Average disease duration was 13.5 (range 3-45) years. Average follow-up for living subjects was 3.1 years and average ALSFRS-R score was 23.5 compared to 25.9 (12-24 months earlier), indicating slow disease progression. ALS was confirmed by post mortem examination in 97% of cases. Eighty-six percent of cases were TDP-43-positive. Additional neuropathological diagnoses include Lewy body disease (13%), frontotemporal lobar degeneration (6.3%), chronic traumatic encephalopathy with motor neuron disease (3.2%), and Alzheimer's disease (2.1%). Tissue RIN values were ≥ 4.0 in 88% of cases. In conclusion, the availability of high quality fixed and frozen CNS tissue from this well characterized cohort is an important resource to facilitate research into genetic and environmental risk factors and clinical pathological relationships in ALS.

Diagnostic accuracy using diffusion tensor imaging in the diagnosis of ALS: a meta-analysis

RATIONALE AND OBJECTIVES

A number of studies have reported decreases in fractional anistropy (FA) in amyotrophic lateral sclerosis using diffusion tensor imaging (DTI). The purpose of this study was to perform a meta-analysis in order to estimate the diagnostic test accuracy measures of DTI for the diagnosis of amyotrophic lateral sclerosis (ALS).

MATERIALS AND METHODS

We searched MEDLINE (1966-April 2011), EMBASE (1999-April 2011), CINAHL (1999-April 2011), and Cochrane (2005-April 2011) databases to identify studies that measured FA in ALS subjects. Human, single-center studies using a DTI region of interest (ROI) or tractography techniques were used to compare FA values along the brain corticospinal tracts between ALS subjects and healthy controls. There were no language restrictions. Independent extraction of articles by 2 authors using predefined data fields including study quality indicators. We identified 30 case-control studies that used region of interest or tractography DTI techniques. We applied binormal receiver operative characteristic (ROC) curve analysis to assign specificity and sensitivity for each study. We applied the bivariate mixed-effects regression model using the Markov Chain Monte Carlo Simulation to calculate summary estimates for the sensitivity and specificity. We used the metan module in Stata, version 11.0, to calculate the area under the ROC curve, diagnostic odds ratio and the test effectiveness summary estimates.

RESULTS

The pooled sensitivity was 0.65 (95% CI 0.61-0.69); the pooled specificity, 0.67 (95% CI 0.63-0.72); the pooled diagnostic odds ratio, 1.88 (95% CI 1.46-2.30); the pooled test effectiveness, 1.04 (95% CI 0.81-1.27); and the pooled area under the ROC curve, 0.76 (95% CI 0.71-0.81). Subanalyses comparing magnetic resonance imaging (MRI) field strength (1.5T vs. 3.0T) and brain location (corticospinal tract average vs. internal capsule) revealed no significant differences in the test accuracy measures. Reference standard used for the diagnosis of ALS was the El Escorial criteria. There was at least moderate heterogeneity between the studies. True study quality is uncertain.

CONCLUSION

The discriminatory capability of DTI to make a diagnosis of ALS is only modest. There were no significant differences in the diagnostic test accuracy summary estimates with respect to MRI field strength or brain location.

Young-onset amyotrophic lateral sclerosis: historical and other observations

There is a wide range of age at initial symptom onset in amyotrophic lateral sclerosis despite a mean age of 65 years in population-based studies. 'Young-onset' amyotrophic lateral sclerosis typically refers to patients younger than ∼45 years and accounts for about 10% of cases in contemporary series. A review of published cases of amyotrophic lateral sclerosis from 1850 to 1950 revealed a far higher proportion of cases with young onset (>50%), with a steady decline to the contemporary figure. It is possible that this is not solely explained by increases in life expectancy. While there is still a rich variation in phenotypes among cases of young-onset amyotrophic lateral sclerosis, bulbar onset was found to be significantly under-represented in analysis of a large patient database, with implications for age-related vulnerabilities pertaining to focality of symptom onset. The timing of initiating pathological processes in relation to the emergence of symptoms is discussed, including the potential role of very early development and the interaction of epigenetic and environmental factors.

Decreased motor cortex γ-aminobutyric acid in amyotrophic lateral sclerosis

OBJECTIVES

To determine if there are in vivo differences in γ-aminobutyric acid (GABA) in the motor cortex and subcortical white matter of patients with amyotrophic lateral sclerosis (ALS) compared with healthy controls using proton magnetic resonance spectroscopy (1H-MRS).

METHODS

In this cross-sectional study, 10 patients with ALS and 9 age- and sex-matched healthy controls (HCs) underwent 3T edited 1H-MRS to quantify GABA centered on the motor cortex and the subcortical white matter.

RESULTS

Compared with healthy controls, patients with ALS had significantly lower levels of GABA in the left motor cortex (1.42 ± 0.27 arbitrary institutional units vs. 1.70 ± 0.24 arbitrary institutional units, p = 0.038). There was no significant difference in GABA levels between groups in the subcortical white matter (p > 0.05).

CONCLUSION

Decreased levels of GABA are present in the motor cortex of patients with ALS compared to HCs. Findings are consistent with prior reports of alterations in GABA receptors in the motor cortex as well as increased cortical excitability in the context of ALS. Larger, longitudinal studies are needed to confirm these findings and to further our understanding of the role of GABA in the pathogenesis of ALS.

A decerebrate adult mouse model for examining the sensorimotor control of locomotion

As wild-type and genetically modified mice are progressively becoming the predominant models for studying locomotor physiology, the technical ability to record sensory and motor components from adult mice, in vivo, are expected to contribute to a better understanding of sensorimotor spinal cord networks. Here, specific technical and surgical details are presented on how to produce an adult decerebrate mouse preparation that can reliably produce sustained bouts of stepping, in vivo, in the absence of anesthetic drugs. Data are presented demonstrating the ability of this preparation to produce stepping during treadmill locomotion, adaptability in its responses to changes in the treadmill speed, and left-right alternation. Furthermore, intracellular recordings from motoneurons and interneurons in the spinal cord are presented from preparations where muscle activity was blocked. Intraaxonal recordings are also presented demonstrating that individual afferents can be recorded using this preparation. These data demonstrate that the adult decerebrate mouse is a tractable preparation for the study of sensorimotor systems.

Modifying effect of arterial hypertension on amyotrophic lateral sclerosis

Given the high oxygen consumption of motor neurons, we sought to assess the frequency and prognostic value of arterial hypertension (affecting brain's oxygen supply) in amyotrophic lateral sclerosis (ALS). We consecutively and prospectively included all ALS patients with regular medical follow-up and documented blood pressure measurements and monitored them until death. Vascular factors diagnosed prior to the onset of motor signs in ALS patients were compared with those in a stratified, age- and gender-matched case-control population. The severity of leukoaraiosis on magnetic resonance imaging (MRI) was blindly assessed. Post mortem examinations were performed when authorized. Compared with controls (n = 408), the 102 ALS patients were significantly more likely to display hypertension (41-57%) and current smoking (15-26%). The number of years of hypertension was associated with survival (HR = 1.04 (1.01-1.07)). In a multivariate analysis, leukoaraiosis severity (HR = 1.214 (1.096-1.344)), current smoking (HR = 1.766 (1.085-2.872)) and low vital capacity (HR = 2.422 (1.266-4.633)) remained independent predictors of survival. Post mortem examinations revealed a greater frequency of leukoaraiosis in ALS patients (p = 0.02). In conclusion, the effect of chronic hypertension on survival might be exerted through abnormal neural perfusion. The higher frequency of recent hypertension in ALS patients may be due to a compensatory increase in blood pressure in response to a lower oxygen supply.

Motoneuron afterhyperpolarisation duration in amyotrophic lateral sclerosis

Motor unit (MU) potentials were registered from 20 ALS patients and 13 age-matched control individuals during isometric constant force contractions of brachial biceps (BB). The registered signals were decomposed into single MU potential trains. The estimates of duration of the afterhyperpolarisation (AHP) in MNs, derived from the interspike interval variability, was compared between ALS patients (124 MNs) and control subjects (111 MNs) and no significant differences were encountered. However, the relationship between TI and age for patients appeared to be qualitatively different from that of the control group. The dependence of patients' AHPs on relative force deficit (RFD), which quantified muscle involvement, was more specific. For RFDs below 30%, the AHP estimate was significantly lower than control values and then increased thereafter with increasing RFDs. Moreover, firing rates of patients with the smallest RFDs were significantly higher while firing rates of patients with the greatest RFDs were significantly lower than control values. The AHP shortening in the early stages of muscle impairment is consistent with the decrease in firing threshold of ‘fast' MNs found in spinal cord slices from neonatal SOD1 mice. The later elongation of the AHP may be caused by the higher vulnerability of ‘fast' MNs to degeneration and by the influence of reinnervation. Our results are comparable to what has been observed in acute experiments in animal models, providing a bridge between animal and clinical research that may be relevant for identification of mechanism(s) underlying neurodegeneration in ALS.

Prognosis of ALS: comparing data from the Limousin referral centre, France, and a Uruguayan population

Our objective was to compare clinical features and survival in two groups of ALS patients from countries in opposite hemispheres. The study took place at an ALS referral centre in the Limousin region of France (LIM) and in Uruguay (UY). All consecutive patients diagnosed with ALS between 1 January 2002 and 31 December 2004 were enrolled. Data from a total of 187 ALS patients were analysed: 84 from LIM and 103 from UY. Mean ages at onset and diagnosis were significantly higher in LIM (66 vs. 61 years). UY patients demonstrated more advanced disease at the time of diagnosis. The proportions of definite forms were 82% in UY versus 10% in LIM (p<0.001), and median manual muscle testing (MMT) and ALSFRS scores were significantly lower in LIM. This observed difference was not directly explained by a longer diagnostic delay in UY (10 vs. 9 months). Median survival from time of diagnosis was significantly shorter in UY patients (19 vs. 28 months; log-rank test, p=0.030). In conclusion, survival of ALS patients in UY is nine months shorter than in LIM, probably due to the heterogeneity of medical care and the absence of an ALS referral centre.

Factors associated with survival in the National Registry of Veterans with ALS

The clinical course of patients with ALS is highly variable. While the median survival time from symptom onset is 2-4 years, there are reports of survival ranging from less than a year to more than 40 years. Such variability makes planning difficult for patients and physicians, and complicates clinical trial design. We sought to validate previous predictors of survival and search for new ones using a large group of ALS patients in the National Registry of Veterans with ALS. We were especially interested in how various aspects of military service might affect survival. Subjects were those in the National Registry of Veterans with ALS who had probable or definite ALS (according to El Escorial criteria). A multivariable Cox proportional hazard regression model was used to examine variables for statistical association with ventilator-free survival time (determined from date of first diagnosis). Subjects who had not died or started ventilation by 31 October 2006 were censored. Our group of 1085 US military veterans with ALS was primarily male (98%) and white (94%), with mostly sporadic (95%) and extremity-onset (76%) ALS. Symptom onset occurred at a mean age of 59.3 years (60.6 years for diagnosis). Median survival time from symptom onset was 4.7 years (3.3 years from diagnosis). In our multivariable model, older age at diagnosis (HR 1.41 (95% CI 1.27-1.55) per 10-year increase), non-extremity site of onset (HR 1.55 (1.24-1.94)), and past deployment to Vietnam (HR 1.73 (1.36-2.19)) were all associated with shortened survival. A longer time to diagnosis was associated with better survival (HR 0.77 (0.70-0.84) per one year increase in diagnosis time). In this unique cohort of veterans with ALS, traditional factors of reduced survival remained important. In addition, past deployment to Vietnam was found to be associated with shortened survival as well. This finding could be due to a common exposure, a shared characteristic, an unmeasured confounder, or an enrollment bias. More research will be needed to understand the reasons behind this new finding.

Study of 962 patients indicates progressive muscular atrophy is a form of ALS

BACKGROUND

Progressive muscular atrophy (PMA) is clinically characterized by signs of lower motor neuron dysfunction and may evolve into amyotrophic lateral sclerosis (ALS). Whether PMA is actually a form of ALS has important consequences clinically and for therapeutic trials. We compared the survival of patients with PMA or ALS to analyze the clinical features that influence survival in PMA.

METHODS

We reviewed the medical records of patients with PMA (n = 91) or ALS (n = 871) from our ALS Center and verified survival by telephoning the families or using the National Death Index.

RESULTS

In PMA, patients were more likely to be male (p < 0.001), older (p = 0.007), and lived longer (p = 0.01) than in ALS. Cox model analysis suggested that the risk of death increased with age at onset in both patient groups (p < 0.005). Upper motor neuron (UMN) signs developed in 22% of patients with PMA within 61 months after diagnosis. Demographic and other clinical variables did not differ at diagnosis between those who did or did not develop UMN signs. In PMA, the factors present at diagnosis that predicted shorter survival were greater number of body regions affected, lower forced vital capacity, and lower ALS Functional Rating Scale-Revised score. Noninvasive ventilation and gastrostomy were used frequently in PMA.

CONCLUSION

Although patients with progressive muscular atrophy (PMA) tended to live longer than those with amyotrophic lateral sclerosis (ALS), shorter survival in PMA is associated with the same risk factors that predict poor survival in ALS. Additionally, PMA is relentlessly progressive, and UMN involvement can occur, as also reported in imaging and postmortem studies. For these reasons, PMA should be considered a form of ALS.

Prognostic factors in ALS: A critical review

We have performed a systematic review to summarize current knowledge concerning factors related to survival in ALS and to evaluate the implications of these data for clinical trials design. The median survival time from onset to death ranges from 20 to 48 months, but 10-20% of ALS patients have a survival longer than 10 years. Older age and bulbar onset are consistently reported to have a worse outcome. There are conflicting data on gender, diagnostic delay and El Escorial criteria. The rate of symptom progression was revealed to be an independent prognostic factor. Psychosocial factors, FTD, nutritional status, and respiratory function are also related to ALS outcome. The effect of enteral nutrition on survival is still unclear, while NIPPV has been found to improve survival. There are no well established biological markers of progression, although some are likely to emerge in the near future. These findings have relevant implications for the design of future trials. Randomization, besides the type of onset, should take into account age, respiratory status at entry, and a measure of disease progression pre-entry. Alternative trial designs can include the use of natural history controls, the so-called minimization method for treatment allocation, and the futility approach.

Amyotrophic lateral sclerosis: Prognostic indicators of survival

Amyotrophic lateral sclerosis (ALS) has a fatal outcome in about three years, but survival is known to vary considerably, making it difficult to predict disease duration in individual cases. The aim of this study was to investigate possible early prognostic factors of ALS survival. We included 123 probable or definite cases of ALS, with disease onset between 1989 and 1998, and with a follow-up of at least one year. Survival functions were obtained using both the Kaplan-Meier and the actuarial methods. Subgroups, formed on the basis of gender, area of residence, work, and age at and site of onset, were compared using the logrank test and Cox's proportional hazards method (survival functions), and applying the Grizzle, Starmer, Koch (1969), and Koch, Johnson, Tolley (1972) methods (one-year survival probability trends). The survival curves dipped sharply in the first three years, followed by a flattening trend, with 50% of patients dying within 2.5 years, and 89% over seven years. The clinical form with lower limb onset was associated with longer survival than the upper limb onset and bulbar forms (median survival: 39, 27, and 25 months, respectively). Survival was also affected by age at onset (median survival: 34, 27, and 23 months for onset <60, 60-75, and >75 years, respectively), area of residence (median survival: 24 months in mountainous areas, 32 elsewhere), and type of work (median survival: 25 months in agricultural workers, 33.5 in others). Gender did not influence survival, whereas percutaneous endoscopic gastrostomy placement and invasive ventilation did. The estimation of individual ALS survival is important to allow the patient to plan for his future and to make optimal use of medical and community resources. Although age at and site of onset, area of residence, and agricultural work were found to influence survival, there remains an unexplained heterogeneous progression of the disease, suggesting the influence of other, as yet unknown, prognostic factors. The identification of a definite set of prognostic factors may allow physicians to make more reliable survival predictions at diagnosis.

Survival of 793 patients with amyotrophic lateral sclerosis diagnosed over a 28-year period

Immunological disturbances have been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). Adhesion molecules are markers of activated endothelial cells up-regulated by action of cytokines. To investigate the activation or inactivation of the vascular cells in ALS, serum soluble intercellular adhesion molecule-1 (s-ICAM-1) and soluble E-selectin (s-ELAM-1) were evaluated (ELISA) in 16 patients with ALS, 30 patients with non-inflammatory neurological diseases (NINDS) and 15 healthy control subjects. Patients with ALS had no higher s-ICAM-1 levels compared with the NINDS patients and the control subjects (p<0.31 and p<0.21, respectively). s-ELAM levels were not statistically significant compared with the NINDS patients and healthy subjects (p<0.21 and p<0.24, respectively). We conclude that the low values of s-ICAM-1 and s-ELAM-1 in the serum of ALS patients do not exclude the presence of immunological abnormality in this disorder. Soluble E-selectin is a glycoprotein which is considered an exclusive marker of endothelial activation. Its low level in our study may suggest a neural rather than an endothelial s-ICAM origin in patients with ALS.

Analysis of factors that modify susceptibility and rate of progression in amyotrophic lateral sclerosis (ALS)

We conducted case-control and prospective longitudinal studies to examine risk factors and predictors of disease progression for ALS. Ninety-five subjects with ALS and 106 healthy control subjects were enrolled. All subjects completed a risk factor questionnaire at enrollment. The ALS subjects were prospectively followed for one year to define factors that influence the rate of disease progression, measured by rate of change in percent predicted forced vital capacity (%FVC) and the ALS functional rating scale (ALSFRS) score. The association of each potential risk factor with ALS was determined using univariate logistic regression. A random slope model was used to determine the association of each risk factor with disease progression. The demographic characteristics of ALS subjects and controls at enrollment did not differ. Significant risk factors for ALS included reported exposure to lead (p = 0.02) and pesticides (p = 0.03). Disease progression was faster in the ALS subjects having bulbar onset and a shorter time period between onset of symptoms and diagnosis. Pertinent variables not associated with either causation or progression of ALS included physical activity, cigarette smoking and a history of physical trauma or other clinical disorders.

Prognostic factors for survival in amyotrophic lateral sclerosis patients treated with riluzole

The objective of this study was to identify prognostic factors for survival in amyotrophic lateral sclerosis from a large prospective observational study performed in France. The study included a cohort of 2069 patients fulfilling broad entry criteria treated with riluzole. Over 100 demographic, biological, clinical and quality-of-life variables were monitored and assessed for their effect on survival. Patients were randomized post hoc into two groups: one group (two-thirds of the patients) to generate the prognostic models and one group (one-third of the patients) to validate the resulting models. Thirteen variables were found to affect survival independently and were used to construct a survival prediction score, RL401. These included age, disease duration, slow vital capacity, intensity of tiredness (visual analogue scale), number of body levels with spasticity, atrophy and/or fasciculations, cough, distal muscle strength, household income, depression and two biological parameters, plasma creatinine levels and neutrophil counts. A simplified score, RL401S, was constructed, designed to be easy to use and interpret. The predictive powers of the two scores were similar.

Primary lateral sclerosis, hereditary spastic paraplegia and amyotrophic lateral sclerosis: Discrete entities or spectrum?

Among the motor neuron diseases, three share the clinical features of prominent upper motor neuron signs--amyotrophic lateral sclerosis (ALS), primary lateral sclerosis (PLS) and the hereditary spastic paraplegias (HSP). While genetic testing can assist in the identification of several variants of the latter, in the remaining cases, including those in which spasticity may be associated with amyotrophy, clinical differentiation of the three disorders may prove difficult. In this paper we review the evidence that these are distinct disorders and conclude that, for ALS and PLS particularly, there may be justification in considering them as single points along a continuum of multisystem disorders with conspicuous motor neuron involvement. Only through the development and application of exacting clinical diagnostic criteria to epidemiological studies, along with greater numbers of post-mortem examinations, however, will these questions be answered fully.

Age at onset influences on wide-ranged clinical features of sporadic amyotrophic lateral sclerosis

PURPOSE

To profile the detailed clinical features of sporadic amyotrophic lateral sclerosis (ALS) on large-scale samples in Japan.

METHODS

We assessed the clinical features of sporadic ALS patients in Japan, based on the nationwide registration system of the Ministry of Health, Labor and Welfare of Japan. We described 3,428 new cases registered cases between 2003 and 2006 to analyze initial symptoms and related clinical features, 4,202 cases registered in the single year of 2005 to describe the cross-sectional overview of the ALS patients, and a total of 2,128 cases with tracheostomy positive pressure ventilation (TPPV) from all of the registration data from 2003 to 2006 to describe the features of ALS patients with TPPV.

RESULTS

The patients with an older age at onset progressed more rapidly to the TPPV stage than those with a younger age at onset. The subpopulation of patients with long-standing TPPV showed ophthalmoplegia, while its appearance rate was less in the patients with an older age at onset than in those with a younger age at onset. Furthermore, age at onset strongly influenced the frequency of initial symptoms: dysarthria, dysphagia, neck weakness and respiratory disturbance were more frequent in patients with an older age at onset, while upper or lower limb weakness was observed more frequently in patients with a younger age at onset. In addition, those initial symptoms were still the most prominent at the follow-up stage, suggesting that the initial symptoms determine the major clinical features even in advanced illness.

CONCLUSIONS

Our present study demonstrated that symptomatic features of ALS are strongly influenced by the age at onset by the large scale of samples.

Drug therapy in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating condition characterized by progressive muscle wasting, inanition, respiratory failure, and death within approximately 2 to 5 years of onset. ALS is among the most common neuromuscular conditions, with an overall prevalence in the world of approximately 5 to 7 cases/100,000 population. Epidemiologic studies have identified some potential risk factors for developing ALS, including a high-fat, low-fiber diet; cigarette smoking; slimness and athleticism; and living in urban areas. Between 5% and 10% of ALS is genetic, with up to 11 genetic loci identified. Although understanding of the pathophysiology of this disease has advanced over the past 60 years, scant progress has been made regarding effective treatment. The authors review the current understanding of the pathogenic mechanisms of ALS and approaches to treating the disease.

Disease progression and survival in ALS: first multi-state model approach

Although several prognostic factors have been identified in ALS, there remains some discordance concerning the prognostic significance of the age and clinical form at onset. In order to clarify these findings, we have analysed already known prognostic factors using a multi-state model. Two hundred and twenty-two sporadic ALS patients were followed. A simple unidirectional three-states model was used to summarize clinical course of ALS. States 1 and 2 reflected the progression of neurological impairment and state 3 represented the end of follow-up (tracheotomy or death). Gender, diagnostic delay, body mass index (BMI) and slow vital capacity (SVC) were also recorded. A time-inhomogeneous Markov model with piecewise constant transition intensities was used to estimate the effect of the covariates in each transition. The bulbar form at onset was only correlated with a more rapid clinical progression between state 1 and state 2. In contrast, an advanced age at diagnosis affected only survival from state 2. This methodological approach suggests that these two factors have a different prognostic significance: age at onset is related to patient's survival and the clinical form at onset predicts the progression of motoneuronal impairment in different regions.

Earlier onset and shorter survival of amyotrophic lateral sclerosis in Jewish patients of North African origin. A clue to modifying genetic factors?

Amyotrophic lateral sclerosis (ALS) is a multifactorial disease, with many genetic and environmental factors contributing to its outcome. The population of Israel is comprised of immigrants from all over the world as well as by Arabs. People with different ethnic backgrounds who live in the same environment provide a unique opportunity to analyze genetic and environmental influences on ALS. We performed a retrospective analysis of 374 sporadic ALS patients whose origin was European in 211, North African in 53, Oriental in 43, Balkan in 19, Arab in 9, and Yemenite in 7, comparing their age at disease onset, gender, disease form at onset, survival, smoking habits, cognitive dysfunction and apolipoprotein E genotype. Patients of North African origin were significantly younger and had a shorter duration of disease relative to their age compared to other ethnic groups, adjusted for age. The difference between the patient groups might be related to a genetic burden in North African patients and warrants further investigation.