Brain plasticity in the motor network is correlated with disease progression in amyotrophic lateral sclerosis.

OBJECTIVE: To test the influence of functional cerebral reorganization in amyotrophic lateral sclerosis (ALS) on disease progression. METHODS: Nineteen predominantly right-handed ALS patients and 21 controls underwent clinical evaluation, functional Magnetic Resonance Imaging (fMRI), and diffusion tensor imaging. Patients were clinically re-evaluated 1 year later and followed until death. For fMRI, subjects executed and imagined a simple hand-motor task. Between-group comparisons were performed, and correlations were searched with motor deficit arm Medical Research Council (MRC) score, disease progression ALS Functional Rating Scale (ALSFRS), and survival time. RESULTS: By the MRC score, the hand strength was lowered by 12% in the ALS group predominating on the right side in accordance with an abnormal fractional anisotropy (FA) limited to the left corticospinal tract (37.3% reduction vs. controls P < 0.01). Compared to controls, patients displayed overactivations in the controlateral parietal (P < 0.004) and somatosensory (P < 0.004) cortex and in the ipsilateral parietal (P < 0.01) and somatosensory (P < 0.01) cortex to right-hand movement. Movement imagination gave similar results while no difference occurred with left-hand tasks. Stepwise regression analysis corrected for multiple comparisons showed that controlateral parietal activity was inversely correlated with disease progression (R(2) = 0.43, P = 0.001) and ipsilateral somatosensory activations with the severity of the right-arm deficit (R(2) = 0.48, P = 0.001). CONCLUSIONS: Cortical Blood Oxygen Level Dependent (BOLD) signal changes occur in the brain of ALS patients during a simple hand-motor task when the motor deficit is still moderate. It is correlated with the rate of disease progression suggesting that brain functional rearrangement in ALS may have prognostic implications.

Phenotype difference between ALS patients with expanded repeats in C9ORF72 and patients with mutations in other ALS-related genes.

BACKGROUND: Expanded GGGGCC hexanucleotide repeats in the promoter of the C9ORF72 gene have recently been identified in frontotemporal dementia (FTD), Amyotrophic Lateral Sclerosis (ALS) and ALS-FTD and appear as the most common genetic cause of familial (FALS) and sporadic (SALS) forms of ALS. METHODS: We searched for the C9ORF72 repeat expansion in 950 French ALS patients (225 FALS and 725 SALS) and 580 control subjects and performed genotype-phenotype correlations. RESULTS: The repeat expansion was present in 46% of FALS, 8% of SALS and 0% of controls. Phenotype comparisons were made between FALS patients with expanded C9ORF72 repeats and patients carrying another ALS-related gene (SOD1, TARDBP, FUS) or a yet unidentified genetic defect. SALS patients with and without C9ORF72 repeat expansions were also compared. The C9ORF72 group presented more frequent bulbar onset both in FALS (p<0.0001 vs SOD1, p=0.002 vs TARDBP, p=0.011 vs FUS, p=0.0153 vs other FALS) and SALS (p=0.047). FALS patients with C9ORF72 expansions had more frequent association with FTD than the other FALS patients (p<0.0001 vs SOD1, p=0.04 vs TARDBP, p=0.004 vs FUS, p=0.03 vs other FALS). C9ORF72-linked FALS patients presented an older age of onset than SOD1 (p=0.0139) or FUS mutation (p<0.0001) carriers. Disease duration was shorter for C9ORF72 expansion carriers than for SOD1 (p<0.0001) and TARDBP (p=0.0242) carriers, other FALS (p<0.0001) and C9ORF72-negative SALS (p=0.0006). CONCLUSIONS: Our results confirm the major role of expanded repeats in C9ORF72 as causative for ALS and provide evidence for specific phenotypic aspects compared to patients with other ALS-related genes.

Quantitative assessment of the evolution of cerebellar signs in spinocerebellar ataxias.

BACKGROUND: Responsive ataxia rating scales are essential for determining outcome measures in clinical trials. METHODS: We evaluated the responsiveness over time of the composite cerebellar functional severity score, a quantitative score measuring cerebellar ataxia in 133 patients with autosomal dominant cerebellar ataxias (ADCA), which were prospectively evaluated at inclusion and after one-year of follow-up. A more responsive tool was developed, the Cerebellar Functional Severity score writing, incorporating the writing test at dominant hand to the Cerebellar Functional Severity score. RESULTS: Within the one-year follow-up period, the Cerebellar Functional Severity score and its writing version increased significantly and the Scale for the Assessment and Rating of Ataxia decreased significantly reflecting increased severity of the cerebellar symptoms. The Cerebellar Functional Severity score writing responsiveness was best in genotypes SCA1, 2, and 3 compared with the other genotypes (effect size = 0.196, standardized response mean (SRM) = 0.624 versus effect size = -0.051, SRM = -0.150). The Cerebellar Functional Severity score writing used as an outcome measure would require only 163 SCA1, 2, or 3 patients per group in a two-arm interventional trial for a 50% reduction in progression and 80% of power. DISCUSSION: Our study demonstrates that the Cerebellar Functional Severity score and Cerebellar Functional Severity score writing are responsive quantitative scores for evaluating sensitivity to change in ADCA patients and can be used as outcome measures in clinical trials, especially when targeting genotypes SCA1, 2 and 3.

SOD1, ANG, VAPB, TARDBP, and FUS mutations in familial amyotrophic lateral sclerosis: genotype-phenotype correlations.

BACKGROUND: Mutations in SOD1, ANG, VAPB, TARDBP and FUS genes have been identified in amyotrophic lateral sclerosis (ALS). METHODS: The relative contributions of the different mutations to ALS were estimated by systematically screening a cohort of 162 families enrolled in France and 500 controls (1000 chromosomes) using molecular analysis techniques and performing phenotype-genotype correlations. RESULTS: 31 pathogenic missense mutations were found in 36 patients (20 SOD1, 1 ANG, 1 VAPB, 7 TARDBP and 7 FUS). Surprisingly two FUS mutation carriers also harboured ANG variants. One family of Japanese origin with the P56S VAPB mutation was identified. Seven novel mutations (three in SOD1, two in TARDBP, two in FUS) were found. None of them was detected in controls. Segregation of detected mutations with the disease was confirmed in 11 families including five pedigrees carrying the novel mutations. Clinical comparison of SOD1, TARDBP, FUS and other familial ALS patients (with no mutation in the screened genes) revealed differences in site of onset (predominantly lower limbs for SOD1 and upper limbs for TARDBP mutations), age of onset (younger with FUS mutations), and in lifespan (shorter for FUS carriers). One third of SOD1 patients survived more than 7 years: these patients had earlier disease onset than those presenting with a more typical course. Differences were also observed among FUS mutations, with the R521H FUS mutation being associated with longer disease duration. CONCLUSIONS: This study identifies new genetic associations with ALS and provides phenotype-genotype correlations with both previously reported and novel mutations.

Cerebrospinal fluid detection of enterovirus genome in ALS: a study of 242 patients and 354 controls.

Detection of enterovirus (EV) in the spinal cord of patients with amyotrophic lateral sclerosis (ALS) has been reported on post mortem central nervous system tissues. In cases of persistent infection, it is very likely that the EV genome might be detected in the cerebrospinal fluid (CSF). A study was conducted in seven French amyotrophic lateral sclerosis (ALS) centres between 1997 and 2002. A total of 242 ALS patients and 354 age- and sex-matched controls (non-ALS patients) were enrolled. A sensitive RT-PCR method was performed on the CSF to assess the presence of EV RNA; 14.5% of ALS patients were positive compared to 7.6% of controls (chi(2) value, 5.31; p = 0.02). Although EV infection has a seasonal pattern, we observed no seasonality in positive detection of the EV genome among ALS patients. There was no significant relationship among ALS patients between the initial clinical form or survival and the result of the RT-PCR. These findings suggest a relationship between the presence of EV sequences in CSF and ALS. Our study is consistent with the hypothesis that persistent EV infection can be one of the multiple factors involved in the development of ALS.

Composite cerebellar functional severity score: validation of a quantitative score of cerebellar impairment.

Reliable and easy to perform functional scales are a prerequisite for future therapeutic trials in cerebellar ataxias. In order to assess the specificity of quantitative functional tests of cerebellar dysfunction, we investigated 123 controls, 141 patients with an autosomal dominant cerebellar ataxia (ADCA) and 53 patients with autosomal dominant spastic paraplegia (ADSP). We evaluated four different functional tests (nine-hole pegboard, click, tapping and writing tests), in correlation with the scale for the assessment and rating of cerebellar ataxia (SARA), the scale of functional disability on daily activities (part IV of the Huntington disease rating scale), depression (the Public Health Questionnaire PHQ-9) and the EQ-5D visual analogue scale for self-evaluation of health status. There was a significant correlation between each functional test and a lower limb score. The performance of controls on the functional tests was significantly correlated with age. Subsequent analyses were therefore adjusted for this factor. The performances of ADCA patients on the different tests were significantly worse than that of controls and ADSP patients; there was no difference between ADSP patients and controls. Linear regression analysis showed that only two independent tests, the nine-hole pegboard and the click test on the dominant side (P < 0.0001), accounted for the severity of the cerebellar syndrome as reflected by the SARA scores, and could be represented by a composite cerebellar functional severity (CCFS) score calculated as follows: [Formula: see text]. The CCFS score was significantly higher in ADCA patients compared to controls (1.12 +/- 0.18 versus 0.85 +/- 0.05, P(c) < 0.0001) and ADSP patients (1.12 +/- 0.18 versus 0.90 +/- 0.08, P(c) < 0.0001) and was correlated with disease duration (P < 0.0001) but independent of self-evaluated depressive mood in ADCA. Among genetically homogeneous subgroups of ADCA patients (Spinocerebellar ataxia 1, 2, 3), SCA3 patients had significantly lower (better) CCFS scores than SCA2 (P(c) < 0.04) and the same tendency was observed in SCA1. Their CCFS scores remained significantly worse than those of ADSP patients with identified SPG4 mutations (P < 0.0001). The pegboard and click tests are easy to perform and accurately reflect the severity of the disease. The CCFS is a simple and validated method for assessing cerebellar ataxia over a wide range of severity, and will be particularly useful for discriminating paucisymptomatic carriers from affected patients and for evaluating disease progression in future therapeutic trials.

Unusual association of amyotrophic lateral sclerosis and myasthenia gravis: A dysregulation of the adaptive immune system?

Myasthenia gravis is an autoimmune disorder affecting neuromuscular junctions that has been associated with a small increased risk of amyotrophic lateral sclerosis (ALS). Here, we describe a retrospective series of seven cases with a concomitant diagnosis of ALS and myasthenia gravis, collected among the 18 French reference centers for ALS in a twelve year period. After careful review, only six patients strictly met the diagnostic criteria for both ALS and myasthenia gravis. In these patients, limb onset of ALS was reported in five (83%) cases. Localization of myasthenia gravis initial symptoms was ocular in three (50%) cases, generalized in two (33%) and bulbar in one (17%). Median delay between onset of the two conditions was 19 months (6-319 months). Anti-acetylcholine receptor antibodies testing was positive in all cases. All patients were treated with riluzole and one had an associated immune-mediated disease. In the one last ALS case, the final diagnosis was false-positivity for anti-acetylcholine receptor antibodies. The co-occurrence of ALS and myasthenia gravis is rare and requires strict diagnostic criteria. Its demonstration needs thoughtful interpretation of electrophysiological results and exclusion of false positivity for myasthenia gravis antibody testing in some ALS cases. This association may be triggered by a dysfunction of adaptive immunity.

Genetic analysis of SS18L1 in French amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a devastating motor neuron disease including about 15% of genetically determined forms. A de novo mutation in the SS18L1 (also known as CREST or KIAA0693) gene encoding the calcium-responsive transactivator and/or neuronal chromatin remodeling complex subunit has recently been identified by exome sequencing of 47 sporadic ALS trios. This Q388stop mutation deleting the last 9 amino acids was shown to impair activity-dependent dendritic outgrowth. A missense mutation (c.369T>G, p.Ileu123Met) was also found in 1 of 62 ALS families previously screened for other ALS-related genes and not carrying any mutation. To confirm the contribution of SS18L1 to ALS, we sequenced the 11 coding exons and exon-intron boundaries in 87 familial ALS (FALS). We identified 2 variants: the c.660_668del, p.Gln222_Ser224del in a patient devoid of mutation in any ALS related genes and the c.790G>A, p.Ala264Thr in a patient carrying a p.Arg96Leu variant in the OPTN gene. As these variants were not found in Single Nucleotide Polymorphism databases and were absent from 180 controls they could be new SS18L1 mutations causing ALS.

Absence of airway secretion accumulation predicts tolerance of noninvasive ventilation in subjects with amyotrophic lateral sclerosis.

OBJECTIVE: To assess factors that predict good tolerance of noninvasive ventilation (NIV), in order to improve survival and quality of life in subjects with amyotrophic lateral sclerosis. METHODS: We conducted a prospective study in subjects with amyotrophic lateral sclerosis and requiring NIV. The primary end point was NIV tolerance at 1 month. Subjects, several of whom failed to complete the study, were classified as "tolerant" or "poorly tolerant," according to the number of hours of NIV use (more or less than 4 h per night, respectively). RESULTS: Eighty-one subjects, 73 of whom also attended the 1-month follow-up visit, participated over 34 months. NIV tolerance after the first day of utilization predicted tolerance at 1 month (77.6% and 75.3% of subjects, respectively). Multivariate analysis disclosed 3 factors predicting good NIV tolerance: absence of airway secretions accumulation prior to NIV onset (odds ratio 11.5); normal bulbar function at initiation of NIV (odds ratio 8.5); and older age (weakly significant, odds ratio 1.1). CONCLUSION: Our study reveals 3 factors that are predictive of good NIV tolerance, in particular the absence of airway secretion accumulation, which should prompt NIV initiation before its appearance.

Neurological features in adult Triple-A (Allgrove) syndrome.

Triple-A or Allgrove syndrome is a rare multisystem disease classically associated with esophageal achalasia, adrenal insufficiency and alacrima. Here, we describe the poorly understood neurological characteristics often associated with this condition, through the clinical and electrophysiological analysis of eight patients. All patients were genetically confirmed and had a mutation in the ALADIN gene. They all displayed a classical picture of Triple-A syndrome: all suffered from achalasia and alacrima and half of them from adrenal insufficiency. However, all harbored a neurological picture characterized by a recognizable pattern of peripheral neuropathy. Other neurological features included cognitive deficits, pyramidal syndrome, cerebellar dysfunction, dysautonomia, neuro-ophthalmological signs and bulbar and facial symptoms. This neurological picture was prominent in all patients and misled the initial diagnosis in six of them, which had a late onset. We then review the previous neurological reports of this disease, to improve the understanding of this rare condition. Diagnosis of late-onset Triple-A syndrome is difficult when the clinical picture is mainly neurological and when endocrine or gastrointestinal signs are minor. The characteristics of the peripheral neuropathy, among other neurological signs, can be of help.

Mutations in UBQLN2 are rare in French amyotrophic lateral sclerosis.

Mutations in UBQLN2 encoding ubiquilin-2 have recently been identified in families with dominant X-linked juvenile and adult-onset amyotrophic lateral sclerosis (ALS) and ALS/dementia. Ubiquilin-2 is a component of the ubiquitin inclusions detected in degenerating neurons in ALS patients. All the previously reported UBQLN2 mutations were localized in 1 of the 12 PXX domains of ubiquilin-2 protein. We sequenced UBQLN2 in 130 French patients with familial ALS (FALS) and absence of male-to-male transmission and the PXX domain in 240 more patients with sporadic ALS (SALS). We identified, at the heterozygote state, the c.1500_1508delCATAGGCCC, p.Gly502_Ile504del, in 1 affected woman. This deletion presumably leads to the in-frame deletion of 1 PXX repeat in the protein. This variant did not segregate with the disease in the corresponding family and was also detected in 1/380 control subject. Our results suggest that UBQLN2 gene mutations are rare in French ALS.

Factors influencing disease progression in autosomal dominant cerebellar ataxia and spastic paraplegia.

OBJECTIVES: To evaluate disease progression and determine validity of clinical tools for therapeutic trials. DESIGN: Prospective cohort study (36 months). SETTING: Referral center. PATIENTS: One hundred sixty-two patients with autosomal dominant cerebellar ataxia and 64 with hereditary spastic paraplegia. MAIN OUTCOME MEASURES: The quantitative Composite Cerebellar Functional Severity Score with the writing test (CCFSw) and Scale for the Assessment and Rating of Ataxia (SARA) score. RESULTS: Disease worsened in patients with SCA1, SCA2, and SCA3 mutations (mean [SE] increase in CCFSw, +0.014 [0.005] to +0.025 [0.004] per year), improved in patients with SPG4 mutations (mean [SE] increase in CCFSw, -0.012 [0.003] per year; P = .02), and remained stable in patients with SCA6, SCA7, or other SCA mutations (mean [SE] increase in CCFSw, -0.015 [0.011] to +0.009 [0.013] per year) or hereditary spastic paraplegia with other SPG mutations (mean [SE] increase in CCFSw, -0.005 [0.005] per year). Progression was faster in patients with SCA2 mutations and normal alleles with 22 or fewer repeats (P = .02) and in patients with SCA3 mutations with parkinsonism and/or dystonia at baseline (P = .003). Whereas CCFSw distinguished between patients with ataxia and spasticity, SARA scores increased in both groups. A 2-arm trial with SARA score as the outcome measure would require 57 patients with SCA2 mutations, 70 with SCA1 mutations, and 75 with SCA3 mutations per group to detect a 50% reduction in disease progression (power, 80%; α = .05). CONCLUSIONS: Disease progressed faster in SCA s with polyglutamine expansions in SCA1, 2, and 3 than the other groups. Both outcome measures are suitable for therapeutic trials; SARA requires fewer patients to attain the same power, but CCFSw needs less stratification. We demonstrate that the choice of clinical outcome measure is critical for reliable evaluation of progression in neurodegenerative diseases.

Screening of OPTN in French familial amyotrophic lateral sclerosis.

Mutations in OPTN gene encoding optineurin have recently been identified at the homozygote and heterozygote state in Japanese families with slowly progressive amyotrophic lateral sclerosis (ALS). OPTN had previously been involved in adult primary open angle glaucoma (POAG). We sequenced the coding exons of OPTN in 126 French patients with familial ALS (FALS). We identified, at the heterozygote state, the nonsense c.382_383insAG variant (also called 691_692insAG), alternatively reported as a causative mutation for primary open angle glaucoma (POAG) or a rare polymorphism and the new p.Arg96Leu variant in a family with dominant ALS. Western blot experiments on the patients' lymphoblasts showed that the former variant led to a loss of function and the latter did not cause protein accumulation. Our results do not confirm the contribution of OPTN in ALS.