Features Of Amyotrophic Lateral Sclerosis Research Articles

The clinical features of amyotrophic lateral sclerosis: diagnosis, natural history and epidemiology

The clinical features of amyotrophic lateral sclerosis: diagnosis, natural history and epidemiology

A transgenic mouse expressing CHMP2Bintron5 mutant in neurons develops histological and behavioural features of amyotrophic lateral sclerosis and frontotemporal dementia.

Mutations in the charged multivesicular body protein 2B (CHMP2B) are associated with frontotemporal dementia (FTD), amyotrophic lateral sclerosis (ALS), and with a mixed ALS-FTD syndrome. To model this syndrome, we generated a transgenic mouse line expressing the human CHMP2Bintron5 mutant in a neuron-specific manner. These mice developed a dose-dependent disease phenotype. A longitudinal study revealed progressive gait abnormalities, reduced muscle strength and decreased motor coordination. CHMP2Bintron5 mice died due to generalized paralysis. When paralyzed, signs of denervation were present as attested by altered electromyographic profiles, by decreased number of fully innervated neuromuscular junctions, by reduction in size of motor endplates and by a decrease of sciatic nerve axons area. However, spinal motor neurons cell bodies were preserved until death. In addition to the motor dysfunctions, CHMP2Bintron5 mice progressively developed FTD-relevant behavioural modifications such as disinhibition, stereotypies, decrease in social interactions, compulsivity and change in dietary preferences. Furthermore, neurons in the affected spinal cord and brain regions showed accumulation of p62-positive cytoplasmic inclusions associated or not with ubiquitin and CHMP2Bintron5 As observed in FTD3 patients, these inclusions were negative for TDP-43 and FUS. Moreover, astrogliosis and microgliosis developed with age. Altogether, these data indicate that the neuronal expression of human CHMP2Bintron5 in areas involved in motor and cognitive functions induces progressive motor alterations associated with dementia symptoms and with histopathological hallmarks reminiscent of both ALS and FTD.

Selective Expression of Osteopontin in ALS-resistant Motor Neurons is a Critical Determinant of Late Phase Neurodegeneration Mediated by Matrix Metalloproteinase-9.

Differential vulnerability among motor neuron (MN) subtypes is a fundamental feature of amyotrophic lateral sclerosis (ALS): fast-fatigable (FF) MNs are more vulnerable than fast fatigue-resistant (FR) or slow (S) MNs. The reason for this selective vulnerability remains enigmatic. We report here that the extracellular matrix (ECM) protein osteopontin (OPN) is selectively expressed by FR and S MNs and ALS-resistant motor pools, whereas matrix metalloproteinase-9 (MMP-9) is selectively expressed by FF MNs. OPN is secreted and accumulated as extracellular granules in ECM in three ALS mouse models and a human ALS patient. In SOD1G93A mice, OPN/MMP-9 double positivity marks remodeled FR and S MNs destined to compensate for lost FF MNs before ultimately dying. Genetic ablation of OPN in SOD1G93A mice delayed disease onset but then accelerated disease progression. OPN induced MMP-9 up-regulation via αvβ3 integrin in ChAT-expressing Neuro2a cells, and also induced CD44-mediated astrocyte migration and microglial phagocytosis in a non-cell-autonomous manner. Our results demonstrate that OPN expressed by FR/S MNs is involved in the second-wave neurodegeneration by up-regulating MMP-9 through αvβ3 integrin in the mouse model of ALS. The differences in OPN/MMP-9 expression profiles in MN subsets partially explain the selective MN vulnerability in ALS.

Discordant performance on the ‘Reading the Mind in the Eyes’ Test, based on disease onset in amyotrophic lateral sclerosis

Executive dysfunction is a core feature of amyotrophic lateral sclerosis (ALS) and is associated with brain atrophy in cortical and subcortical regions. Social cognitive deficits may also be a prominent feature of ALS. This study investigated executive, and social cognitive performance, in a population based cohort of patients with ALS, stratified by disease onset. Participants were recruited as part of a population based study investigating cognitive decline in ALS. Patients carrying pathogenic C9orf72 hexanucleotide repeat were excluded. Participants were stratified based on bulbar (n = 20) or spinal (n = 39) disease onset (n = 59). Matched healthy controls were used to generate culturally specific comparative data for within-patient analyses (n = 59). Results showed that ALS patients performed significantly worse than controls on a number of measures of executive function. When sub-stratified by disease onset, there was a significant difference between bulbar- and spinal-onset patients with respect to the ‘Reading the Mind in the Eyes’ Test scores (p < 0.001). Conversely, standardized scores of executive function did not differ between the patient groups. In conclusion, patients performed significantly worse than matched controls on measures of executive function. Bulbar-onset ALS patients evidenced more social-affective deficits compared to spinal-onset patients, with matched performance on measures of executive function.

Dissociated Small Hand Muscle Atrophy Occurs in Amyotrophic Lateral Sclerosis: Split Hand

Split hand is a peculiar atrophy of hand muscle and was named by Willbourn in 1992. In this phenomenon, the hypothenar muscle is relatively preserved, but the thenar and the first dorsal interossei (FDI) muscles are preferentially involved. Some studies have measured compound muscle action potential (CMAP) amplitudes of intrinsic hand muscles in various neurological diseases and have revealed that this phenomenon is a specific feature of amyotrophic lateral sclerosis (ALS). The measurements of CMAP amplitude in intrinsic hand muscles may be useful for diagnosis of ALS. FDI and thenar muscles are innervated by the same ulnar nerve and same spinal segments (C8 and Th1), although atrophies of these muscles are dissociated. Anatomical innervations are not enough to explain this phenomenon. Motor neuronal hyperexcitability potentially contributes to motor neuron death in ALS, and in several articles, it is reported to be the possible mechanism of this phenomenon. In healthy controls and ALS patients, cortical and peripheral motor nerves, which project to the thenar and FDI muscles, may be more excitable than those of the hypothenar muscle. This article reviews the findings of previous articles about the utility of this phenomenon as a diagnostic marker, and its potential mechanisms.

Which behaviours? Identifying the most common and burdensome behaviour changes in amyotrophic lateral sclerosis

Behaviour change is increasingly recognised as a common feature of amyotrophic lateral sclerosis (ALS), and may be similar to that seen in frontotemporal dementia (FTD). The behaviours most disturbed in ALS, and those that relate most significantly to caregiver burden, however, have not been well established. Forty ALS participants and their caregivers, and 27 age- and gender-matched healthy controls and their relatives, participated in this study. ALS participants were assessed on a disease rating scale, and caregivers and control informants completed the revised version of the Cambridge Behaviour Inventory and a measure of burden. ALS caregivers reported significantly more disturbance than healthy control informants on the functional domains of everyday skills, self-care, and sleep, and in the behavioural domains of mood and motivation. There were no differences between groups in frequency of memory and orientation difficulties, or behaviours characteristic of FTD, such as changes to eating habits or stereotypic and motor behaviour, indicating that the behavioural profile in ALS may differ from FTD. In the ALS group, the domains with the strongest relationship to caregiver burden were everyday skills, motivation and memory, likely because poor motivation, memory dysfunction and difficulties completing activities of daily living require more carer support via direct supervision, prompting or hands on care. Services to support ALS patients and caregivers need to provide targeted interventions for those functional and behavioural changes which are most burdensome in the disease.

Cortical contributions to the flail leg syndrome: Pathophysiological insights

Cortical hyperexcitability has been identified as an intrinsic feature of amyotrophic lateral sclerosis (ALS). Consequently, the aim of the present study was to determine whether cortical hyperexcitability formed the pathophysiological basis for the flail leg syndrome (FL), an atypical ALS variant. Cortical excitability studies were undertaken on 18 FL patients, using the threshold tracking transcranial magnetic stimulation (TMS) technique, and results were compared to healthy controls, upper and lower limb-onset ALS as well as bulbar-onset and the flail arm variant ALS. Results showed that cortical hyperexcitability was a feature of FL and was heralded by a significant reduction of short-interval intracortical inhibition (FL 7.2 ± 1.8%; controls 13.2 ± 0.8%, p <0.01) and cortical silent period (CSP) duration (FL 181.7 ± 10.8ms; controls 209.8 ± 3.4ms; p <0.05) along with an increase in motor evoked potential amplitude (FL 29.2 ± 5.1%; controls 18.9 ± 1.2%, p <0.05). The degree of cortical hyperexcitability was comparable between FL and other ALS phenotypes, defined by site of disease onset. In addition, the CSP duration correlated with biomarkers of peripheral neurodegeneration in FL. In conclusion, cortical hyperexcitability is a feature of the flail leg syndrome, being comparable to other ALS phenotypes. Importantly, cortical hyperexcitability correlates with neurodegeneration, and as such may contribute to the underlying pathophysiology in FL.

ALS-linked protein disulfide isomerase variants cause motor dysfunction.

Disturbance of endoplasmic reticulum (ER) proteostasis is a common feature of amyotrophic lateral sclerosis (ALS). Protein disulfide isomerases (PDIs) areERfoldases identified as possibleALSbiomarkers, as well as neuroprotective factors. However, no functional studies have addressed their impact on the disease process. Here, we functionally characterized fourALS-linked mutations recently identified in two majorPDIgenes,PDIA1 andPDIA3/ERp57. Phenotypic screening in zebrafish revealed that the expression of thesePDIvariants induce motor defects associated with a disruption of motoneuron connectivity. Similarly, the expression of mutantPDIs impaired dendritic outgrowth in motoneuron cell culture models. Cellular and biochemical studies identified distinct molecular defects underlying the pathogenicity of thesePDImutants. Finally, targetingERp57 in the nervous system led to severe motor dysfunction in mice associated with a loss of neuromuscular synapses. This study identifiesERproteostasis imbalance as a risk factor forALS, driving initial stages of the disease.

19. Cortical hyperexcitability in ALS: A heterogeneous process

Objective Cortical hyperexcitability, as heralded by reduced short interval intracortical inhibition (SICI) has been identified as an intrinsic feature of amyotrophic lateral sclerosis (ALS). However, in approximately 20% of patients cortical excitability may be normal, suggesting the presence of pathophysiological heterogeneity. Consequently, the present study assessed for the presence of clinical, functional and neurophysiological differences in ALS phenotypes, as defined by cortical hyperexcitability. Methods Cortical excitability was assessed in 62 ALS patients. Clinical, functional and neurophysiological parameters were compared between ALS patients with cortical hyperexcitability (SICI 5.5%) versus those with a “normal” level of cortical excitability (SICI > 5.5%). Results In ALS patients with features of cortical hyperexcitability, there appeared to be an absence of SICI in the early phase (interstimulus interval [ISI] 1–3 ms) with a transition to facilitation at later ISIs (3.5–7 ms). In contrast, ALS patients with normal SICI demonstrated similar levels of inhibition across early and late SICI phases. Of further relevance, ALS patients with abnormal SICI exhibited increased mortality in follow-up. Conclusion Dysfunction in cortical inter-neuronal circuits probed by short latency paired-pulse TMS appears to capture some of the pathophysiological heterogeneity in ALS and may have direct implications for survival.

Prion-like propagation of mutant SOD1 misfolding and motor neuron disease spread along neuroanatomical pathways.

A hallmark feature of amyotrophic lateral sclerosis (ALS) is that symptoms appear to spread along neuroanatomical pathways to engulf the motor nervous system, suggesting a propagative toxic entity could be involved in disease pathogenesis. Evidence for such a propagative entity emerged recently in studies using mice that express G85R-SOD1 mutant protein fused to YFP (G85R-SOD1:YFP). Heterozygous G85R-SOD1:YFP transgenic mice do not develop ALS symptoms out to 20 months of age. However, when newborns are injected with spinal homogenates from paralyzed mutant SOD1 mice, the G85R-SOD1:YFP mice develop paralysis as early as 6 months of age. We now demonstrate that injecting spinal homogenates from paralyzed mutant SOD1 mice into the sciatic nerves of adult G85R-SOD1:YFP mice produces a spreading motor neuron disease within 3.0 ± 0.2 months of injection. The formation of G85R-SOD1:YFP inclusion pathology spreads slowly in this model system; first appearing in the ipsilateral DRG, then lumbar spinal cord, before spreading rostrally up to the cervical cord by the time mice develop paralysis. Reactive astrogliosis mirrors the spread of inclusion pathology and motor neuron loss is most severe in lumbar cord. G85R-SOD1:YFP inclusion pathology quickly spreads to discrete neurons in the brainstem and midbrain that are synaptically connected to spinal neurons, suggesting a trans-synaptic propagation of misfolded protein. Taken together, the data presented here describe the first animal model that recapitulates the spreading phenotype observed in patients with ALS, and implicates the propagation of misfolded protein as a potential mechanism for the spreading of motor neuron disease.

Hydrogen peroxide-mediated induction of SOD1 gene transcription is independent from Nrf2 in a cellular model of neurodegeneration

BackgroundIt is still unclear whether oxidative stress (OS) is a disease consequence or is directly involved in the etiology of neurodegenerative disorders (NDs) onset and/or progression; however, many of these conditions are associated with increased levels of oxidation markers and damaged cell components. Previously we demonstrated the accumulation of reactive oxygen species (ROS) and increased SOD1 gene expression in H2O2-treated SH-SY5Y cells, recapitulating pathological features of Amyotrophic Lateral Sclerosis (ALS). Since we observed a post-transcriptional regulation of SOD1 gene in this cellular model, we investigated the transcriptional regulation of SOD1 mRNA under oxidative stress (OS). ResultsIn response to H2O2 treatment, PolII increased its association to SOD1 promoter. Electrophoretic mobility shift assays and mass spectrometry analyses on SOD1 promoter highlighted the formation of a transcriptional complex bound to the ARE sequences. Western Blotting experiments showed that in our in vitro model, H2O2 exposure increases Nrf2 expression in the nuclear fraction while immunoprecipitation confirmed its phosphorylation and release from Keap1 inhibition. However, H2O2 treatment did not modify Nrf2 binding on SOD1 promoter, which seems to be regulated by different transcription factors (TFs). ConclusionsAlthough our data suggest that SOD1 is transcriptionally regulated in response to OS, Nrf2 does not appear to associate with SOD1 promoter in this cellular model of neurodegeneration. Our results open new perspectives in the comprehension of two key antioxidant pathways involved in neurodegenerative disorders.

Epidemiologycal and clinical features of amyotrophic lateral sclerosis in Uzbekistan

Epidemiologycal and clinical features of amyotrophic lateral sclerosis in Uzbekistan

Amyotrophic lateral sclerosis in Slovenia – analysis of patient population at the Ljubljana Institute of Clinical Neurophysiology

Backgorund: Data on epidemiology and disease characteristics of amyotrophic lateral sclerosis (ALS) are geographically limited and no systematically collected data exist for slovenian patients. We performed a retrospective descriptive study on clinical attributes and disease course of patients with ALS treated at the Institute of clinical neurophysiology (ICN), University Medical Centre Ljubljana since the foundation of a specialised ALS group.Methods: All 271 patients treated at ICN in the 10-year period between 2003 and 2012 were analysed. Data on basic demographic characteristics, phenotype of disease onset, diagnostic delay, survival, family history, use of percutaneous gastrostomy (PEG), of non-invasive ventilation and of riluzole were obtained.Results: Mean age at symptoms onset was 62.7 ± 11.4 years, median diagnostic delay 11 (IQ range 7–19) months and mean survival from time of enrolment 16.4 ± 15.1 months. 179 (66.1%)patients had spinal onset disease and 71 (26.2%) bulbar onset disease. Factors associated with longer survival were lower age at enrolment, longer diagnostic delay and use of PEG. The proportion of patients using non-invasive ventilatory support was rising through the analysed years.Conclusions: Disease characteristics and survival in our series are similar to data from other tertiary care centres. The need for non-invasive ventilatory support in ALS patients is increasing.

Elevated caspase 3 activity and cytosolic cytochrome c in NT2 cybrids containing amyotrophic lateral sclerosis subject mtDNA

Apoptosis of motor neurons is an important feature in amyotrophic lateral sclerosis (ALS). A vital role of mitochondria in apoptosis and cell survival is well documented. Eventually mitochondria have shown to be an early target in the pathogenesis of ALS. On account of these facts, we investigated the involvement of mitochondrial-dependent apoptosis in ALS and control (CTR) cybrids, generated fusing human platelets with mitochondrial DNA-depleted NT2-neuroteratocarcinoma cells. After a 6 week selection process during which transferred subject mtDNA repopulated the NT2 cells and restored mitochondrial oxygen consumption, we assessed cell viability and two programmed cell death parameters, caspase 3 activity and cytosolic cytochrome c levels. Compared to the control cybrid lines (n = 5), the ALS cybrid lines (n = 10) showed 45% less XTT reduction and higher caspase 3 activity ( p < 0.05, two-way Student's t test) exhibiting lesser cell viability and execution of apoptosis. Elevated cytosolic cytochrome c levels in ALS cybrid lines (n = 8) than in CTR (n = 4) ( p < 0.05, two-way Student's t-test) indicating its mitochondrial release and initiation of apoptosis. This indicates apoptosis as one of the possible mechanisms of cell death in ALS. Our findings support the view that in ALS, subject's mitochondria are altered in non-degenerating tissues in such a way that intrinsic apoptotic pathway activity is relatively increased.

Motor function and behaviour across the ALS-FTD spectrum.

Behavioural/functional disturbances, characteristic of frontotemporal dementia (FTD), are also a feature of amyotrophic lateral sclerosis (ALS) and patients with combined ALS and FTD (FTD-ALS). To investigate the progression of behavioural disturbances in ALS and FTD using the FTD functional rating scale (FTDFRS). Patients with ALS, FTD-ALS and FTD were recruited from specialist clinics. Baseline assessments included the FTDFRS and the ALS functional rating scale-revised (ALSFRS-R). Baseline assessments were included, as were longitudinal assessments in a proportion of patients. In total, 21 ALS, 12 FTD-ALS and 14 behavioural variant FTD (bvFTD) patients were included in the study. Moderate or severe behavioural disturbance was common in patients with ALS at baseline (47.6%), although less frequent than in bvFTD patients; patients with FTD-ALS displayed intermediate impairment. The ALSFRS-R showed the opposite pattern and did not correlate with the FTDFRS. During the follow-up period, significant (P < 0.05) behavioural deterioration was demonstrated in patients with bvFTD and FTD-ALS, with a trend for decline in patients with ALS (P = 0.06). Motor disturbance is the primary marker of disease severity in ALS, but behavioural and functional impairment are common, and may decline independently of motor function. As such, the FTDFRS may provide valuable information in the assessment and monitoring of ALS.

Clinical features of amyotrophic lateral sclerosis in south-west China

Our objective was to profile clinical features of amyotrophic lateral sclerosis (ALS); we performed a large sample, cross-sectional study based on a hospital registry of ALS in south-west China. Patients were coded in our tertiary referral centre from May 2006 to September 2014. Demographic data and disease-related parameters were collected. A total of 1131 patients were included. Mean age of onset was 54.3 ± 11.6 years and the highest proportion of onset age (30.6%) was between 51 and 60 years. Male:female ratio was 1.45:1. Nearly 30% of the patients were young onset, and 20.3% of the patients were bulbar onset; only 35% received riluzole treatment. The young-onset patients had a higher educational level with a higher proportion performing manual labour and living in rural areas, and a lower proportion with bulbar onset than those who were older at onset. The bulbar-onset patients were older at age of onset, with a lower proportion of males than spinal-onset patients. In conclusion, Chinese ALS patients may be younger at age of onset than Caucasian patients. Environmental and geographical factors are related to the occurrence of ALS. The large treatment gap indicated a pressing need for medical and financial support for Chinese ALS patients.

A single blind randomized controlled clinical trial of mexiletine in amyotrophic lateral sclerosis: Efficacy and safety of sodium channel blocker phase II trial

Fasciculations are characteristic features of amyotrophic lateral sclerosis (ALS), and suggest motor nerve hyperexcitability. Recent reports have shown that an increase in persistent nodal sodium current is associated with shorter survival in ALS patients. This objective of this trial is to study the efficacy and safety of mexiletine, a sodium channel blocker, for ALS. Sixty eligible participants were randomly allocated (1:1) to riluzole 100 mg or riluzole plus mexiletine 300 mg. The primary endpoint was change in the revised ALS functional rating scale (ALSFRS-R) scores during six months. We also monitored strength-duration time constant (SDTC, a measure of persistent sodium current) in median motor axons. Results showed that during six months of treatment, changes in the ALSFRS-R score and SDTC were –7.0 ± 7.1 and –0.04 ± 0.1, respectively, in the riluzole group and –6.9 ± 6.4 and 0.04 ± 0.1, respectively, in the mexiletine group (p = 0.96 and 0.049). Adverse events amounted 20% in the riluzole and 33% in the mexiletine groups. In conclusion, the results suggest that daily 300 mg mexiletine has no effects on axonal sodium current and ALSFRS-R deterioration in ALS. We have to attempt another trial using a higher dose of mexiletine or other agents to suppress sodium currents and ALS progression in the future.

Identification of rare protein disulfide isomerase gene variants in amyotrophic lateral sclerosis patients

Disruption of endoplasmic reticulum (ER) proteostasis is a salient feature of amyotrophic lateral sclerosis (ALS). Upregulation of ER foldases of the protein disulfide isomerase (PDI) family has been reported in ALS mouse models and spinal cord tissue and body fluids derived from sporadic ALS cases. Although in vitro studies suggest a neuroprotective role of PDIs in ALS, the possible contribution of genetic mutations of these ER foldases in the disease process remains unknown. Interestingly, intronic variants of the PDIA1 gene were recently reported as a risk factor for ALS. Here, we initially screened for mutations in two major PDI genes (PDIA1/P4HB and PDIA3/ERp57) in a US cohort of 96 familial and 96 sporadic ALS patients using direct DNA sequencing. Then, 463 familial and 445 sporadic ALS patients from two independent cohorts were also screened for mutations in these two genes using whole exome sequencing. A total of nine PDIA1 missense variants and seven PDIA3 missense variants were identified in 16 ALS patients. We have identified several novel and rare single nucleotide polymorphisms (SNPs) in both genes that are enriched in ALS cases compared with a large group of control subjects showing a frequency of around 1% in ALS cases. The possible biological and structural impact of these ALS-linked PDI variants is also discussed.

SERCA1 overexpression in skeletal muscle preserves motor function and delays disease onset in a mouse model of ALS

We previously showed that disruption of intracellular Ca2+ homeostasis in skeletal muscle is one of the pathophysiological features of amyotrophic lateral sclerosis (ALS). The purpose of this study was to investigate whether SERCA1 overexpression would improve motor function and disease progression in ALS mice. B6SJL‐Tg(SOD1*G93A)1Gur/J (ALS) mice were bred with skeletal muscle α‐actinin SERCA1 overexpressing mice to generate: i) wild type (WT; n=11); ii) SERCA1 overexpression (WT/+SERCA1; n=14); iii) SOD1*G93A ALS (ALS; n=7); iv) SERCA1 overexpressing SOD1*G93A ALS mice (ALS/+SERCA1; n=11). Mice were evaluated weekly (9 ‐16 wks) for motor function (grip test) and time of symptom onset and at 16 wks for muscle mass and SERCA1 activity. SERCA1 overexpressing mice had decreased gastrocnemius muscle mass in WT (125.4 ± 5.9 vs. 71.9 ± 13.1 mg; p&lt;0.05 for WT vs. WT/+SERCA1) but increased mass in ALS (59.6 ± 0.1 vs. 73.1 ± 0.1 mg; p&lt;0.05 for ALS vs. ALS/+SERCA1). SERCA1 overexpression resulted in a 1.8‐fold increase in SR Ca2+ ATPase activity in ALS mice (39.9 ± 2.1 vs. 70.4 ± 12.4 umol/g tissue mass/min; p&lt;0.05 for ALS vs. ALS/+SERCA1). This was associated with improved motor function in ALS mice at 14 wks (111.4 ± 16.2 vs. 67.7 ± 13.1 sec; p&lt;0.05) and 16 wks (53.1 ± 11.8 vs. 8.9 ± 3.4 sec; p&lt;0.05) for ALS/+SERCA1 vs. ALS mice and a delay in disease onset (101.9 ± 2.6 vs. 91.1 ± 4.7 days in ALS/+SERCA1 vs. ALS). These data indicate that SERCA1 overexpression in skeletal muscle improves motor function and slows disease progression in a mouse model of ALS. We hypothesize that this is due to improved muscle health and stability of the neuromuscular junction. Increasing SERCA1 expression and/or activity in skeletal muscle may be a new therapeutic strategy to treat ALS.

Clinical varieties and epidemiological aspects of amyotrophic lateral sclerosis in the Caribbean island of Guadeloupe: A new focus of ALS associated with Parkinsonism

Our objective was to evaluate the epidemiological and clinical characteristics of amyotrophic lateral sclerosis (ALS) in the Caribbean island of Guadeloupe, using a retrospective study covering 15 years (1996–2011). Sixty-three cases of ALS were reported, with a frequency of 0.93/100,000/year. The incidence was 4.5-fold higher (3.73/100,00/year) on Marie-Galante, a small island in the Guadeloupe archipelago. ALS was associated with Parkinsonism in 23.8% of the cases. Other phenotypes were typical ALS (47.6%), bulbar forms (20.6%), limb-onset variants (6.3%) and ALS associated with frontotemporal dementia (1.6%). Onset of ALS-Parkinsonism was significantly later than in typical forms of ALS (68 vs. 54 years; p = 0.012) and affected males more frequently than did bulbar ALS (80% vs. 23.2%; p = 0.003). After one year of disease duration, the clinical profile of ALS-Parkinsonism included a symmetric akineto-rigid Parkinsonian syndrome unresponsive to levodopa, supranuclear oculomotor palsy (50%), dementia (66.7%) and signs of both lower (100%) and upper (86%) motor neuron involvement, including bulbar signs (100%). In conclusion, a new cluster of ALS-Parkinsonism and a geographical area with a high frequency of ALS were identified in Guadeloupe, suggesting that they result from environmental or genetic factors. Further studies are needed to explore these hypotheses.