Incidence of amyotrophic lateral sclerosis in Chile.

OBJECTIVE: This study aimed to estimate amyotrophic lateral sclerosis (ALS) incidence and survival rates in the Metropolitan region of Chile. METHODS: We conducted a cohort study of ALS cases in the Metropolitan Region from 2016 to 2019. A total of 219 ALS patients were recruited from Corporación ELA-Chile registry, in collaboration with neurologists from Sociedad de Neurología, Psiquiatría y Neurocirugía de Chile. We calculated incidence rates by sex and age and determined median survival from onset and diagnosis. Survival analysis used the Kaplan-Meier statistic, estimating hazard ratios for age, sex, time from symptom onset and from diagnosis using a Weibull regression model. All analyses were done using R 4.1.0. RESULTS: Overall, ALS diagnosis incidence was 0.97 cases per 100,000 inhabitants, peaking in the 70-79 age group and declining thereafter. The male-to-female ratio was 1.23. The median time to death from diagnosis was 2.3 years (95% confidence interval [CI]: 1.9-2.5), and from the first symptom, it was 3.1 years (95% CI: 2.8-3.5). CONCLUSIONS: This is the first population-based study reporting ALS incidence and survival rates in Chile's Metropolitan region. Incidence resembled other Latin American studies. Median survival from diagnosis and from the first symptom were in line with previous findings. Our results corroborated lower ALS rates in Latin America, consistent with prior research.

Manejo multidisciplinario y avances terapéuticos en la esclerosis lateral amiotrófica / Multidisciplinary care and therapeutic advances in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that mainly affects the motor system, resulting in progressive weakness and muscle wasting. Despite the tremendous advances in physiopathological and clinical characterization, we do not have a curative treatment yet. The progressive and fatal course of ALS makes its management particularly complex and challenging given the diversity of symptoms presenting during the disease progression. The main goal in the treatment of ALS patients is to minimize morbidity and maximize the quality of life. Currently, a series of therapeutic interventions improve the quality of life and prolong survival, including multidisciplinary care, respiratory management, and disease-modifying therapy. Within the supportive interventions, weight maintenance through nutritional and metabolic support is critical. In addition, the management of neuropsychiatric manifestations and preservation of communicative capacity before speech loss are also crucial. Lastly, early palliative care intervention is essential to optimize symptomatic management. Anticipatory guidelines to face the inevitable patient deterioration should be devised. This article updates the main therapeutic strategies used in these patients, including evolving clinical trials with promising novel therapies.

Novel autosomal dominant TPM3 mutation causes a combined congenital fibre type disproportion-cap disease histological pattern.

Tropomyosin 3 (TPM3) gene mutations associate with autosomal dominant and recessive nemaline myopathy 1 (NEM1), congenital fiber type disproportion myopathy (CFTD) and cap myopathy (CAPM1), and a combination of caps and nemaline bodies. We report on a 47-year-old man with polyglobulia, restricted vital capacity and mild apnea hypopnea syndrome, requiring noninvasive ventilation. Physical assessment revealed bilateral ptosis and facial paresis, with high arched palate and retrognathia; global hypotonia and diffuse axial weakness, including neck and upper and lower limb girdle and foot dorsiflexion weakness. Whole body MRI showed a diffuse fatty replacement with an unspecific pattern. A 122 gene NGS neuromuscular disorders panel revealed the heterozygous VUS c.709G>A (p.Glu237Lys) on exon 8 of TMP3. A deltoid muscle biopsy showed a novel histological pattern combining fiber type disproportion and caps. Our findings support the pathogenicity of the novel TPM3 variant and widen the phenotypic gamut of TMP3-related congenital myopathy.

Genetic Profile of Patients with Limb-Girdle Muscle Weakness in the Chilean Population.

Hereditary myopathies are a group of genetically determined muscle disorders comprising more than 300 entities. In Chile, there are no specific registries of the distinct forms of these myopathies. We now report the genetic findings of a series of Chilean patients presenting with limb-girdle muscle weakness of unknown etiology. Eighty-two patients were explored using high-throughput sequencing approaches with neuromuscular gene panels, establishing a definite genetic diagnosis in 49 patients (59.8%) and a highly probable genetic diagnosis in eight additional cases (9.8%). The most frequent causative genes identified were DYSF and CAPN3, accounting for 22% and 8.5% of the cases, respectively, followed by DMD (4.9%) and RYR1 (4.9%). The remaining 17 causative genes were present in one or two cases only. Twelve novel variants were identified. Five patients (6.1%) carried a variant of uncertain significance in genes partially matching the clinical phenotype. Twenty patients (24.4%) did not carry a pathogenic or likely pathogenic variant in the phenotypically related genes, including five patients (6.1%) presenting an autoimmune neuromuscular disorder. The relative frequency of the different forms of myopathy in Chile is like that of other series reported from different regions of the world with perhaps a relatively higher incidence of dysferlinopathy.

The Latin American Epidemiology Network for ALS (Laenals).

Background: There is evolving evidence of non-uniform distribution of ALS worldwide, with apparently lower incident and prevalent rates outside populations of European origin. However, the phenotype, survival and environmental risk in populations of mixed ancestral origin have not been well established. Large scale population based studies of incidence, prevalence, phenotype and risk factors in admixed populations are necessary to determine the true demography of ALS, and to test the hypothesis of differential risk and phenotype in populations of mixed ancestry. Methods: The Latin American Epidemiological Network of ALS (LAENALS) has been established to perform a comparative analysis of ALS epidemiology between three different Latin American populations (Cuba, Uruguay and Chile), and to test the hypothesis that the demographics, phenotype and outcome of ALS are influenced by ancestral origin, and that environmental and occupational risk factors differ across different ethnicities due to subtle differences in gene- environmental interactions. Recognition and interrogation of these differences is an important step toward novel therapeutic approaches and personalized medicine for all ALS both in the US, and worldwide. Discussion: This work will enable direct and detailed comparative studies between different ancestral populations with varying degrees of admixture, with facility for comparison with a large European reference dataset for ALS, and will provide a unique and rich dataset of admixed populations for later comparative genomic studies.

[Multidisciplinary care and therapeutic advances in amyotrophic lateral sclerosis]. / Manejo multidisciplinario y avances terapéuticos en la esclerosis lateral amiotrófica.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that mainly affects the motor system, resulting in progressive weakness and muscle wasting. Despite the tremendous advances in physiopathological and clinical characterization, we do not have a curative treatment yet. The progressive and fatal course of ALS makes its management particularly complex and challenging given the diversity of symptoms presenting during the disease progression. The main goal in the treatment of ALS patients is to minimize morbidity and maximize the quality of life. Currently, a series of therapeutic interventions improve the quality of life and prolong survival, including multidisciplinary care, respiratory management, and disease-modifying therapy. Within the supportive interventions, weight maintenance through nutritional and metabolic support is critical. In addition, the management of neuropsychiatric manifestations and preservation of communicative capacity before speech loss are also crucial. Lastly, early palliative care intervention is essential to optimize symptomatic management. Anticipatory guidelines to face the inevitable patient deterioration should be devised. This article updates the main therapeutic strategies used in these patients, including evolving clinical trials with promising novel therapies.

Inside minds, beneath diseases: social cognition in amyotrophic lateral sclerosis-frontotemporal spectrum disorder.

OBJECTIVE: To compare social cognition performance between patients with amyotrophic lateral sclerosis (ALS) and those patients with behavioural variant frontotemporal dementia (bvFTD). METHODS: We included 21 participants with ALS, 20 with bvFTD and 21 healthy controls who underwent a comprehensive cognitive battery, including the short version of the Social Cognition and Emotional Assessment (Mini-SEA), which comprises the faux pas test and Facial Emotion Recognition Test (FERT); Mini-Mental State Examination; Frontal Assessment Battery; lexical fluency (F-A-S), category fluency (animals/minute), digit span (direct and backwards) tests and the Hayling test. A post hoc analysis was conducted with the patients with ALS divided into two subgroups: patients without cognitive impairment (ALScn; n=13) and patients with cognitive impairment (ALSci; n=8). RESULTS: No significant difference was noted between participant groups in terms of the age, sex and education. ALS-total group and patients with bvFTD had similar disease durations. Patients with ALSci performed poorly when compared with controls with regard to the FERT (p<0.001), the faux pas (p<0.004) and the Mini-SEA (p<0.002) total scores. Moreover, patients with bvFTD performed poorly in comparison with controls in executive and social cognition tests. The performance of patients with ALSci was similar to that of patients with bvFTD, while the performance of patients with ALScn was similar to that of controls. DISCUSSION: Our findings support a cognitive continuum between ALS and bvFTD and shed light on the cognitive heterogeneity of ALS, expanding its possible neuropsychological profiles.

Spinal cord infarction with ipsilateral segmental neuropathic pain and flaccid paralysis. A functional role for human afferent ventral root small sensory fibres.

This paper illustrates the cases of two patients with an acute onset of right brachial neuropathic pain, flaccid paralysis and contralateral thermal and thermal pain hypoesthesia, without posterior column impairment nor pyramidal signs below the segmental lesion. MRI showed right sided spinal cord infarction, in the anterior spinal artery territory between C1 and C5 in one patient and between C3 and C7 in the other. Contact Heat Evoked Potentials and Quantitative Thermal Sensory testing are consistent with contralateral, but not ipsilateral, spinothalamic tract involvement. Electromyographic results established ipsilateral segmental denervation and somatosensory evoked responses were consistent with dorsal column sparing. Unilateral anterior cervical spinal cord infarction may present with acute ipsilateral segmental neuropathic pain, lower motor neurone-type weakness, contralateral thermoanalgesia and no pyramidal signs. The ipsilateral pain provides novel evidence that in some instances, ventral roots can play a role in nociception in humans. The infarcted territory may result from occlusion of a sulcal commissural artery or a number of more proximal vessels (including a single or duplicated anterior spinal artery, vertebral arteries or feeding radicular arteries).

Toward an objective measure of functional disability in dysferlinopathy.

INTRODUCTION: Understanding the natural history of dysferlinopathy is essential to design and quantify novel therapeutic protocols. Our aim in this study was to assess, clinically and functionally, a cohort of patients with dysferlinopathy, using validated scales. METHODS: Thirty-one patients with genetically confirmed dysferlinopathy were assessed using the motor function measure (MFM), Modified Rankin Scale (MRS), Muscle Research Council (MRC) scale, serum creatine kinase (CK) assessment, baseline spirometry data, and echocardiographic and electrophysiologic studies. RESULTS: MFM and MRC scores showed a significant negative correlation with disease duration and inverse correlation with MRS, but not with onset age, clinical phenotype, or CK levels. Percent forced vital capacity (%FVC) correlated negatively with disease duration and onset age. Eight known pathogenic mutations were identified recurrently, 4 of which accounted for 79% of the total. CONCLUSIONS: The results suggest that MFM is a reliable outcome measure that may be useful for longitudinal follow-up in dysferlinopathy. Recurrent mutations suggest a founder effect in the Chilean population.