Incidence and prevalence of Parkinson's disease among Navajo people living in the Navajo nation.

Parkinson's disease (PD) is largely unstudied among American Indians. Unique populations might harbor clues to elusive causes. We describe the incidence and prevalence of PD among Navajo people residing in the Navajo Nation, home to the largest American Indian tribe in the United States. We analyzed 2001-2011 inpatient and outpatient visit data for Navajo people obtained from the Indian Health Service, which provides health care to American Indian people living on the Navajo Reservation. Cases were defined by at least two inpatient or outpatient visits with the diagnosis of PD. Crude and age-adjusted incidence and prevalence rates were calculated overall as well as by age, sex, region of residence, and time period. Five hundred twenty-four Navajo people with median age-at-onset of 74.0 years were diagnosed with PD during the study period, yielding an average annual crude incidence rate of 22.5/100,000. Age-specific incidence was 232.0 for patients 65 years of age or older and 302.0 for 80 years of age or older. Age-adjusted incidence was 35.9 overall (238.1 for ≥65 years), was higher in men than in women (47.5 vs. 27.7; P<0.001), varied by region (P=0.03), and was similar between time periods (2002-2004 vs. 2009-2011). The age-adjusted point prevalence rate was 261.0. The rate of PD among Navajo People appears to be as high as or higher than rates reported in many other populations. Rates increased to the highest age group, consistent with population-based studies. Further investigation is warranted to examine risk factors for PD in this remote population.

A rare motor neuron deleterious missense mutation in the DPYSL3 (CRMP4) gene is associated with ALS.

The dihydropyrimidinase-like 3 (DPYSL3) or Collapsin Response Mediator Protein 4a (CRMP4a) expression is modified in neurodegeneration and is involved in several ALS-associated pathways including axonal transport, glutamate excitotoxicity, and oxidative stress. The objective of the study was to analyze CRMP4 as a risk factor for ALS. We analyzed the DPYSL3/CRMP4 gene in French ALS patients (n = 468) and matched-controls (n = 394). We subsequently examined a variant in a Swedish population (184 SALS, 186 controls), and evaluated its functional effects on axonal growth and survival in motor neuron cell culture. The rs147541241:A>G missense mutation occurred in higher frequency among French ALS patients (odds ratio = 2.99) but the association was not confirmed in the Swedish population. In vitro expression of mutated DPYSL3 in motor neurons reduced axonal growth and accelerated cell death compared with wild type protein. Thus, the association between the rs147541241 variant and ALS was limited to the French population, highlighting the geographic particularities of genetic influences (risks, contributors). The identified variant appears to shorten motor neuron survival through a detrimental effect on axonal growth and CRMP4 could act as a key unifier in transduction pathways leading to neurodegeneration through effects on early axon development.

Metabolomics in cerebrospinal fluid of patients with amyotrophic lateral sclerosis: an untargeted approach via high-resolution mass spectrometry.

Amyotrophic lateral sclerosis (ALS) is characterized by the absence of reliable diagnostic biomarkers. The aim of the study was to (i) devise an untargeted metabolomics methodology that reliably compares cerebrospinal fluid (CSF) from ALS patients and controls by liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS); (ii) ascertain a metabolic signature of ALS by use of the LC-HRMS platform; (iii) identify metabolites for use as diagnostic or pathophysiologic markers. We developed a method to analyze CSF components by UPLC coupled with a Q-Exactive mass spectrometer that uses electrospray ionization. Metabolomic profiles were created from the CSF obtained at diagnosis from ALS patients and patients with other neurological conditions. We performed multivariate analyses (OPLS-DA) and univariate analyses to assess the contribution of individual metabolites as well as compounds identified in other studies. Sixty-six CSF samples from ALS patients and 128 from controls were analyzed. Metabolome analysis correctly predicted the diagnosis of ALS in more than 80% of cases. OPLS-DA identified four features that discriminated diagnostic group (p < 0.004). Our data demonstrate that untargeted metabolomics with LC-HRMS is a robust procedure to generate a specific metabolic profile for ALS from CSF and could be an important aid to the development of biomarkers for the disease.

Predicting survival of patients with amyotrophic lateral sclerosis at presentation: a 15-year experience.

OBJECTIVE: To describe the clinical features at first evaluation that best predict survival of the amyotrophic lateral sclerosis (ALS) population from the Salpêtrière Hospital between 1995 and 2009. METHODS: Data are collected and entered into a clinical database from all patients seen at the Paris ALS Center. Variables analyzed were demographic and baseline information, strength testing (manual muscle testing; 1995-2009), the revised ALS Functional Rating Scale (ALSFRS-R; 2002-2009) and survival status. The χ(2) test and ANOVA assessed differences in variables by region and across time period. Univariate and multivariate Cox proportional hazards models determined which variables best predicted survival. Flexible modeling of continuous predictors (splines) assessed trends in survival for different variables. RESULTS: 3,885 patients with ALS were seen in 1995-2009, of whom 2,037 had ALSFRS-R scores. Age, weight, strength, and site of onset varied by region of residence. The proportion of patients living outside Paris, the time to first visit, patient age, and motor function differed across time periods. In Cox models, site of onset, time to first visit greater than 18 months, strength and the year of visit after 2006 predicted survival (all p values <0.0001). Compared to patients first seen between 1999 and 2002, the hazard ratio of death was 1.04 (95% CI = 0.95-1.14) for 2003-2006, and 0.76 (95% CI = 0.66-0.87) after 2006, while adjusting for other predictors of survival. The use of noninvasive ventilation increased during 2004-2008 from 16 to 51% of patients. CONCLUSIONS: Older age, bulbar onset, shorter delay to first visit and poor motor function at first visit predicted shorter survival rates in this large center-based sample from France, showing marked consistency across time and region of residence. Survival improved after 2006, concurrent with increasing rates of noninvasive ventilation use. Clinicopathologic correlation could better define subgroups, but identification of etiologies may be needed to elucidate individual forms of ALS with unique survival patterns.

Parkinson's disease among American Indians and Alaska natives: a nationwide prevalence study.

BACKGROUND: The objective of this study was to determine the prevalence of Parkinson's disease (PD) among American Indian and Alaska Native (AI/AN) people. METHODS: We analyzed records for AI/AN people between 2002 and 2009 using inpatient and outpatient visit data from the Indian Health Service. Crude and age-adjusted prevalence, using the 2000 projected US population as the standard, was determined overall and by age group, sex, period, and region. RESULTS: An estimated 2613 AI/AN people carried the diagnosis of PD (crude prevalence, 143.8/100,000). Prevalence increased with age through 84 years. The age-adjusted rate was 355.7 and was higher among men than women (P < .0001). Rates differed by region (P < .0001). CONCLUSIONS: Parkinson's disease is prevalent among AI/AN people. The prevalence increases with age, varies by geographic region, and is higher among men than women. Community-based studies are needed to define incidence, examine risk factors, and determine reasons for sex and regional differences in PD among AI/AN people.

Amyotrophic lateral sclerosis: a hormonal condition?

Amyotrophic lateral sclerosis (ALS) is the most frequent motor neuron disorder in adults. This fatal condition, due to degeneration of upper and lower motor neurons in spinal and bulbar myotomes, leads to death from respiratory failure after median disease duration of 36 months. ALS is sporadic in more than 90% of cases and familial in the remaining cases. Most studies show male predominance with a gender ratio of 3:2, but gender differences are age related. The phenotype of ALS is also different in males and females with a predominance of limb onset in males and bulbar onset in females. While age and site of onset impact survival rate, and are both related to gender, gender by itself has not clearly been shown to have an effect on survival. Given this complex relationship between gender and ALS, we developed a hypothesis about hormone involvement in ALS aetiology by suggesting protective effect of oestrogens and adverse effect of androgens.

The range and clinical impact of cognitive impairment in French patients with ALS: a cross-sectional study of neuropsychological test performance.

Our objective was to assess the spectrum and clinical associations of cognitive impairment in French patients with ALS, and determine the effect of cognitive impairment on survival in this population. One hundred and thirty-one patients were enrolled in a cross-sectional cohort study of neuropsychological test performance. ANOVA and χ(2) tests assessed differences in clinical characteristics between impaired and unimpaired patients; multiple regression determined which features contributed most strongly to cognitive status, and Cox models compared survival. Fifty-three patients (40%) were categorized as cognitively impaired based on test performance. Thirteen (10%) patients had frontotemporal dementia (FTD) clinically; all scored in the moderate to severely impaired range on testing. Impaired patients had less education (p = 0.001), and severely impaired patients were more likely to have bulbar onset than unimpaired patients (p < 0.001). Severe cognitive impairment predicted shorter survival (p = 0.007), even when controlled for motor severity (p = 0.001). In summary, 10% of a consecutive series of French ALS patients had overt dementia and 40% were cognitively impaired by neuropsychological testing. We conclude that lower education level and possibly bulbar-onset ALS were associated with impairment. As in other causes of dementia, higher education attainment may protect against clinical cognitive deterioration in ALS. French patients with severe cognitive impairment have shorter survival time.

Changing mortality for motor neuron disease in France (1968-2007): an age-period-cohort analysis.

The incidence and mortality of motor neuron disease (MND) increase with age and appear to have increased with time. The examination of period and cohort effects using age-period-cohort (APC) models can help characterize temporal trends. Our objective was to describe mortality from MND in France (1968-2007), and to examine the role of age, period of death, and birth-cohort on changes in mortality. The number of people who died from MND and population statistics (1968-2007) were extracted from French national records. Annual standardized (age/sex) mortality ratios (SMRs) were computed. Using Poisson regression, APC models examined the relationship between mortality rates and age, period of death, and birth-cohort in subjects aged 40-89 years. Deviance/degrees-of-freedom ratios evaluated model fit; ratios close to one indicated adequate fit. Between 1968 and 2007, 38,863 individuals died from MND (mortality rate = 1.74/100,000); 37,624 were aged 40-89 years. SMRs increased from 54 (95% CI = 49-59) in 1968 to 126 (120-132) in 2007. Male-to-female ratios declined from 1.80 in 1968 to 1.45 in 2007. Changing mortality rates were best explained by cohort effects (deviance/degrees-of-freedom = 1.09). The relative risk of dying from MND increased markedly for persons born between 1880 and 1920, and more slowly after 1920. In conclusion, mortality rates for MND increased between 1968 and 2007, and more rapidly in women than men. This increase was better explained by the birth-cohort of individuals than by period effects. Changing environmental exposures may be a possible explanation and these findings warrant the continued search for environmental risk factors for MND.

Correlates of quality of life in ALS: Lessons from the minocycline study.

Improving quality of life (QoL) is a major goal in ALS palliative care. Previous studies performed on the general ALS population showed no relationship between QoL and disease progression. ALS subjects participating in clinical trials may differ from those in the general ALS population. We explored the relationship between QoL and disease progression in 412 subjects enrolled in a minocycline trial. We examined correlations between Single Item McGill Quality of Life Scale (MQoL-SIS) score and disease duration, ALS Functional Rating Scale Revised (ALSFRS-R) score, FVC, and survival rate. We also analyzed how NIV and PEG affect QoL. Within subjects, MQoL-SIS scores correlated with ALSFRS-R and FVC (p<0.001). MQoL-SIS declined over time (p<0.001) and correlated with the decline of ALSFRS-R (p<0.001). MQoL-SIS tended to improve after initiation of NIV (p=0.07). There was a significant reduction in the rate of MQoL-SIS decline (p<0.001) after initiation of PEG. Subjects with slower QoL decline survived seven months longer than those with faster QoL decline (p<0.01). Our study demonstrated that QoL does decline with advancing ALS in subjects who participated in a minocycline trial, that the slope of QoL predicts survival, and that both NIV and PEG have beneficial impacts on QoL.

A prospective cohort study of neuropsychological test performance in ALS.

Our objective was to determine the prevalence and predictors of cognitive impairment in ALS, measure differences in survival among impaired and unimpaired patients, and assess changes in neuropsychological test performance over time. Fifty patients were enrolled in a prospective cohort study of neuropsychological performance. ANOVA and chi(2) tests assessed differences in clinical characteristics and neuropsychologic test results; general estimating equations assessed change in test performance; multiple regression determined which variables contributed to cognitive status; and Cox models compared survival. Thirty-six patients were categorized as cognitively normal, and 14 were impaired. Impaired patients were older at testing (p = 0.024), but no more likely to have bulbar signs. Predicators of impairment were symptom duration (p < 0.001), motor function (p < 0.001), and rate of ALS progression (p < 0.001). The Benton recognition (p < 0.001), Boston naming (p = 0.001), Wisconsin Card Sort (p = 0.001) and word generation (p = 0.001) tests contributed most strongly to cognitive status. Survival was worse in impaired patients (p = 0.027). Over time, only animal word generation declined (p = 0.016). In conclusion, 28% percent of patients were cognitively impaired. Older age and more severe ALS were associated with impairment. The strongest neuropsychological predictors of cognitive status were measures of executive, episodic memory and language function. Cognitively impaired patients had shorter survival time.

Impaired glucose tolerance in patients with amyotrophic lateral sclerosis.

Our objectives were to analyse carbohydrate metabolism in a series of ALS patients and to examine potential association with parameters of lipid metabolism and clinical features. Glucose tolerance was assessed by the oral glucose tolerance test in 21 non-diabetic ALS patients and compared with 21 age- and sex-matched normal subjects. Lipids and lactate/pyruvate ratio, levels of pro-inflammatory cytokines (tumour necrosis factor-alpha and interleukin-6) and adipocytokines (leptin and adiponectin) were also measured in ALS patients. Mann-Whitney U-tests analysed continuous data and Fisher's exact tests assessed categorical data. Blood glucose determined 120 min after the glucose bolus was significantly higher in patients with ALS (7.41 mmol/l+/-1.68) compared to controls (6.05+/-1.44, p=0.006). ALS patients with impaired glucose tolerance (IGT) according to WHO criteria (n=7, 33%) were more likely to have elevated free fatty acids (FFA) levels compared to patients with normal glucose tolerance (0.77 nmol/l+/-0.30 vs. 0.57+/-0.19, p=0.04). IGT was not associated with disease duration or severity. In conclusion, patients with ALS show abnormal glucose tolerance that could be associated with increased FFA levels, a key determinant of insulin resistance. The origin of glucose homeostasis abnormalities in ALS may be multifactorial and deserves further investigation.

The importance of the SMN genes in the genetics of sporadic ALS.

The human genome contains two SMN (survival motor neuron) genes: SMN1, the telomeric gene whose homozygous deletion causes spinal muscular atrophy (SMA), and SMN2, the centromeric version whose copy number modulates the phenotype of SMA. We performed a Medline search and reviewed all of the publications that focus on SMN1 and SMN2 in amyotrophic lateral sclerosis (ALS) to analyse whether these genes also act as risk factors or phenotypic modulators in ALS. While homozygous deletion of SMN1 was not associated in ALS, abnormal SMN1 copy numbers significantly increased the risk of ALS. The role of the SMN2 gene in ALS needs further clarification. The existence of abnormal SMN1 copy numbers in ALS provides additional evidence that gene copy number variants may contribute to neurodegeneration and might open new approaches to treatment.

Motor unit number estimation (MUNE) in diseases of the motor neuron: utility and comparative analysis in a multimodal biomarker study.

We prospectively studied 64 patients with motor neuron disease (amyotrophic lateral sclerosis (ALS), familial ALS (fALS), progressive muscular atrophy (PMA) and primary lateral sclerosis (PLS)) using multiple point stimulation motor unit number estimation (MUNE), transcranial magnetic stimulation (TMS), proton magnetic resonance spectroscopic imaging (1H MRSI), diffusion tensor imaging (MRDTI), and clinical measures at baseline and every 3 months thereafter for 15 months. Substantial differences in MUNE were noted among the motor neuron disease subgroups (P = 0.0005) and mean values for each motor neuron disease subgroup were significantly lower vs. controls (ALS = 76, fALS = 80, PMA = 29, and PLS = 174) vs. the normal control average (267). MUNE correlated well with % FVC (r = 0.32; P = 0.01), manual muscle testing (r = 0.52; P < 0.0005), grip strength (r = 0.34; P = 0.007), and pinch strength (r = 0.49; P < 0.0005). Overall, MUNE showed the greatest significant change over time of any measure, clinical or otherwise, tested in this study (-2.35 linear trend % change per month, mean). MUNE clearly delineates lower motor neuron dysfunction, strongly correlates with important clinical functions (such as strength and respiration) and is a highly sensitive marker of disease progression over time. These features make MUNE an important tool for both the study of the pathophysiology of the motor neuron diseases, as well as an important measure for incorporation into future clinical trials.

Amyotrophic lateral sclerosis with ragged-red fibers.

BACKGROUND: Motor neuron diseases (amyotrophic lateral sclerosis [ALS] and spinal muscular atrophy [SMA]) have been rarely associated with mitochondrial respiratory chain defects. OBJECTIVES: To describe a patient with typical ALS and the finding of ragged-red fibers in muscle biopsy specimens and to review the literature on respiratory chain defects in ALS and SMA. DESIGN: Case report and review of the literature. SETTING: Collaboration between tertiary care academic hospitals. PATIENT: A 65-year-old man with typical ALS. MAIN OUTCOME MEASURES: The patient had 10% ragged-red fibers and 3% cytochrome-c oxidase-negative fibers in muscle biopsy specimens but no biochemical defects of respiratory chain enzymes or alterations of mitochondrial DNA (mtDNA). RESULTS: Amyotrophic lateral sclerosis with ragged-red fibers has been reported in 5 families and is associated with mtDNA mutations in some subjects. Spinal muscular atrophy without mutations in the survival motor neuron gene (SMN; OMIM 600354) has been associated with mtDNA depletion or with mutations in the cytochrome-c oxidase assembly gene (SCO2; OMIM 604377). CONCLUSION: Respiratory chain defects can mimic ALS or SMA and should be considered in the differential diagnosis.

Oxidative stress biomarkers in sporadic ALS.

We aimed to investigate oxidative stress biomarkers in a cross-sectional pilot study of 50 participants with sporadic ALS (SALS) compared to 46 control subjects. We measured urinary 8-oxodeoxyguanosine (8-oxodG), urinary 15-F(2t)-isoprostane (IsoP), and plasma protein carbonyl by ELISA methods. We also determined if ELISA measurement of 8-oxodG could be validated against measures from high-pressure liquid chromatography coupled with electrochemical detection, the current standard method. We found that 8-oxodG and IsoP levels adjusted for creatinine were significantly elevated in SALS participants. These differences persisted after age and gender were controlled in regression analyses. These markers are highly and positively correlated with each other. 8-oxodG measured by the two techniques from the same urine sample were positively correlated (p<.0001). Protein carbonyl was not different between SALS participants and controls. In conclusion, using ELISA, we confirmed that certain oxidative stress biomarkers were elevated in SALS participants. ELISA may be reliable and thus useful in epidemiology studies requiring large numbers of samples to determine the significance of increased oxidative stress markers in SALS. Further studies are required.

A novel, efficient, randomized selection trial comparing combinations of drug therapy for ALS.

Combining agents with different mechanisms of action may be necessary for meaningful results in treating ALS. The combinations of minocycline-creatine and celecoxib-creatine have additive effects in the murine model. New trial designs are needed to efficiently screen the growing number of potential neuroprotective agents. Our objective was to assess two drug combinations in ALS using a novel phase II trial design. We conducted a randomized, double-blind selection trial in sequential pools of 60 patients. Participants received minocycline (100 mg)-creatine (10 g) twice daily or celecoxib (400 mg)-creatine (10 g) twice daily for six months. The primary objective was treatment selection based on which combination best slowed deterioration in the ALS Functional Rating Scale-Revised (ALSFRS-R); the trial could be stopped after one pool if the difference between the two arms was adequately large. At trial conclusion, each arm was compared to a historical control group in a futility analysis. Safety measures were also examined. After the first patient pool, the mean six-month decline in ALSFRS-R was 5.27 (SD=5.54) in the celecoxib-creatine group and 6.47 (SD=9.14) in the minocycline-creatine group. The corresponding decline was 5.82 (SD=6.77) in the historical controls. The difference between the two sample means exceeded the stopping criterion. The null hypothesis of superiority was not rejected in the futility analysis. Skin rash occurred more frequently in the celecoxib-creatine group. In conclusion, the celecoxib-creatine combination was selected as preferable to the minocycline-creatine combination for further evaluation. This phase II design was efficient, leading to treatment selection after just 60 patients, and can be used in other phase II trials to assess different agents.

Efficacy of minocycline in patients with amyotrophic lateral sclerosis: a phase III randomised trial.

BACKGROUND: Minocycline has anti-apoptotic and anti-inflammatory effects in vitro, and extends survival in mouse models of some neurological conditions. Several trials are planned or are in progress to assess whether minocycline slows human neurodegeneration. We aimed to test the efficacy of minocycline as a treatment for amyotrophic lateral sclerosis (ALS). METHODS: We did a multicentre, randomised placebo-controlled phase III trial. After a 4-month lead-in phase, 412 patients were randomly assigned to receive placebo or minocycline in escalating doses of up to 400 mg/day for 9 months. The primary outcome measure was the difference in rate of change in the revised ALS functional rating scale (ALSFRS-R). Secondary outcome measures were forced vital capacity (FVC), manual muscle testing (MMT), quality of life, survival, and safety. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00047723. FINDINGS: ALSFRS-R score deterioration was faster in the minocycline group than in the placebo group (-1.30 vs -1.04 units/month, 95% CI for difference -0.44 to -0.08; p=0.005). Patients on minocycline also had non-significant tendencies towards faster decline in FVC (-3.48 vs -3.01, -1.03 to 0.11; p=0.11) and MMT score (-0.30 vs -0.26, -0.08 to 0.01; p=0.11), and greater mortality during the 9-month treatment phase (hazard ratio=1.32, 95% CI 0.83 to 2.10; p=0.23) than did patients on placebo. Quality-of-life scores did not differ between the treatment groups. Non-serious gastrointestinal and neurological adverse events were more common in the minocycline group than in the placebo group, but these events were not significantly related to the decline in ALSFRS-R score. INTERPRETATION: Our finding that minocycline has a harmful effect on patients with ALS has implications for trials of minocycline in patients with other neurological disorders, and for how potential neuroprotective agents are screened for use in patients with ALS.

A screening assessment of cognitive impairment in patients with ALS.

We wished to determine whether a screening test battery for cognitive impairment can be given practicably in a busy multidisciplinary ALS clinic, and to assess initial test performance in a sequentially drawn ALS population. We administered a word generation task (letter fluency), the Frontal Behavioral Inventory (FBI), and the Beck Depression Inventory (BDI) to 49 ALS patients and their caregivers during a visit to our ALS clinic. We also computed Clinical Dementia Rating (CDR) scale and ALS Functional Rating Scale (ALSFRS-R) scores for patients. Pearson correlation coefficients and regression analyses assessed associations between outcome measures. The test battery took 30 min to administer. Word generation was associated with the FBI score (r = -0.36, p = 0.01), and time to ALS diagnosis (p = 0.01). Caregiver depressive symptoms (BDI) correlated with the FBI (r = 0.40, p = 0.005) and motor severity (r = -0.47, p<0.01) in patients. CDR scores were associated with behavioral abnormalities and lower ALSFRS-R scores. We concluded that a screen of cognition could be administered during multidisciplinary ALS clinics. Frontostriatal cognitive impairment may be associated with behavioral syndromes and more rapid forms of ALS. Behavioral and motor impairment is associated with depressive symptoms in caregivers. Studies with formal neuropsychological tests are needed to determine the sensitivity and specificity of the screen in ALS.

An observational study of cognitive impairment in amyotrophic lateral sclerosis.

BACKGROUND: Cognitive impairment is increasingly recognized in patients with amyotrophic lateral sclerosis (ALS). Clinical and pathologic features overlap in frontotemporal lobar dementia and ALS. Demographics, respiratory status, bulbar site of onset, and disease severity are potential risk factors for cognitive impairment in ALS. OBJECTIVES: To further delineate the frequency, nature, and implications of cognitive impairment in ALS and to assess previously identified risk factors. DESIGN: Case-control and retrospective cohort study. SETTING: Academic referral center. PARTICIPANTS: Forty consecutive patients with ALS underwent baseline neurologic and neuropsychologic examinations. Cognitive test performance was compared in patients with ALS and matched controls. An exploratory analysis of the relationship between cognitive performance and ALS survival was performed. MAIN OUTCOME MEASURES: Neuropsychologic test performance, ALS severity, and survival. RESULTS: Twelve patients (30%) showed evidence of cognitive impairment, including 9 (23%) who met the neuropsychologic criteria for dementia. No statistically significant differences were found between demented and nondemented ALS groups regarding demographics, family history, site of onset, bulbar dysfunction, or ALS severity. Only 1 patient with dementia had bulbar-onset disease. An association was observed between increasing ALS severity and declining verbal fluency performance. Demented patients with ALS showed predominant impairment in free recall, executive function, and naming, with relative preservation of attention, psychomotor speed, and visuospatial function. No association was observed between cognition and survival, controlling for ALS severity. CONCLUSIONS: Nearly a third of the patients with ALS showed evidence of cognitive impairment in a pattern consistent with frontotemporal lobar dementia. Cognitive performance was not related to site of onset or survival.

Disruption of TCA Cycle and Glutamate Metabolism Identified by Metabolomics in an In Vitro Model of Amyotrophic Lateral Sclerosis.

This study aims to develop a cellular metabolomics model that reproduces the pathophysiological conditions found in amyotrophic lateral sclerosis in order to improve knowledge of disease physiology. We used a co-culture model combining the motor neuron-like cell line NSC-34 and the astrocyte clone C8-D1A, with each over-expressing wild-type or G93C mutant human SOD1, to examine amyotrophic lateral sclerosis (ALS) physiology. We focused on the effects of mutant human SOD1 as well as oxidative stress induced by menadione on intracellular metabolism using a metabolomics approach through gas chromatography coupled with mass spectrometry (GC-MS) analysis. Preliminary non-supervised analysis by Principal Component Analysis (PCA) revealed that cell type, genetic environment, and time of culture influenced the metabolomics profiles. Supervised analysis using orthogonal partial least squares discriminant analysis (OPLS-DA) on data from intracellular metabolomics profiles of SOD1G93C co-cultures produced metabolites involved in glutamate metabolism and the tricarboxylic acid cycle (TCA) cycle. This study revealed the feasibility of using a metabolomics approach in a cellular model of ALS. We identified potential disruption of the TCA cycle and glutamate metabolism under oxidative stress, which is consistent with prior research in the disease. Analysis of metabolic alterations in an in vitro model is a novel approach to investigation of disease physiology.