Insights into phenotypic variability caused by GARS1 pathogenic variants.

BACKGROUND AND PURPOSE: Pathogenic variants of the glycyl-tRNA synthetase 1 (GARS1) gene have been described as a cause of Charcot-Marie-Tooth disease type 2D, motor axonal neuropathy with upper limb predominance (distal hereditary motor neuropathy [dHMN] type V), and infantile spinal muscular atrophy. METHODS: This cross-sectional, retrospective, observational study was carried out on 12 patients harboring the c.794C>T (p.Ser265Phe) missense pathogenic variant in GARS1. The patients' clinical data, nerve conduction studies, magnetic resonance imaging (MRI), and intraepidermal nerve fiber density in skin biopsies were reviewed. RESULTS: The mean age at onset was 9.5 years; the intrinsic hand muscles were affected before or at the same time as the distal leg musculature. The clinical examination revealed greater weakness of the distal muscles, with a more pronounced involvement of the thenar complex and the first dorsal interosseous in upper limbs. Electrophysiological studies were concordant with an exclusively motor axonal neuropathy. A pathologic split hand index was found in six patients. Muscle MRI showed predominant fatty infiltration and atrophy of the anterolateral and superficial posterior compartment of the legs. Most patients reported distal pinprick sensory loss. A reduced intraepidermal nerve fiber density was evident in skin biopsies from proximal and distal sites in nine patients. CONCLUSIONS: GARS1 variants may produce a dHMN phenotype with "split hand" and sensory disturbances, even when sensory nerve conduction studies are normal. This could be explained by a dysfunction of sensory neurons in the dorsal ganglion that is reflected as a reduction of dermal nerve endings in skin biopsies without a distal gradient.

Neurodegeneration Biomarkers in Adult Spinal Muscular Atrophy (SMA) Patients Treated with Nusinersen.

The objective of this study is to evaluate biomarkers for neurodegenerative disorders in adult SMA patients and their potential for monitoring the response to nusinersen. Biomarkers for neurodegenerative disorders were assessed in plasma and CSF samples obtained from a total of 30 healthy older adult controls and 31 patients with adult SMA type 2 and 3. The samples were collected before and during nusinersen treatment at various time points, approximately at 2, 6, 10, and 22 months. Using ELISA technology, the levels of total tau, pNF-H, NF-L, sAPPß, Aß40, Aß42, and YKL-40 were evaluated in CSF samples. Additionally, plasma samples were used to measure NF-L and total tau levels using SIMOA technology. SMA patients showed improvements in clinical outcomes after nusinersen treatment, which were statistically significant only in walkers, in RULM (p = 0.04) and HFMSE (p = 0.05) at 24 months. A reduction in sAPPß levels was found after nusinersen treatment, but these levels did not correlate with clinical outcomes. Other neurodegeneration biomarkers (NF-L, pNF-H, total tau, YKL-40, Aß40, and Aß42) were not found consistently changed with nusinersen treatment. The slow progression rate and mild treatment response of adult SMA types 2 and 3 may not lead to detectable changes in common markers of axonal degradation, inflammation, or neurodegeneration, since it does not involve large pools of damaged neurons as observed in pediatric forms. However, changes in biomarkers associated with the APP processing pathway might be linked to treatment administration. Further studies are warranted to better understand these findings.

Risdiplam in non-sitter patients aged 16 years and older with 5q spinal muscular atrophy.

INTRODUCTION/AIMS: Risdiplam has been approved for the treatment of patients with 5q spinal muscular atrophy (SMA), but data from type 2 non-sitter patients are lacking. In this study we describe our experience regarding the use of risdiplam in a series of type 2 non-sitter patients. METHODS: Type 2 SMA patients over 16 years of age were administered risdiplam through the expanded access program (NCT04256265). Patients were followed-up with a battery of scales and clinical measures. RESULTS: Six non-sitter patients (17 to 46 years old) were treated with risdiplam. One patient reported mild adverse events (dyspepsia and headache). After 1 year of treatment, all patients showed clinically meaningful improvements in at least one scale and none of them showed any clinically meaningful deterioration. Two patients showed a clinically meaningful increase in body mass index (>5%) and two others scored higher on the Revised Upper Limb Module (>2 points). Moreover, five patients had clinically meaningful improvements on the Egen Klassifikation 2 scale (>2 points), including the motor (axial and upper limbs), bulbar (speech and swallowing), and respiratory (coughing) domains. Four subjects achieved at least one of the goals set with the Goal Attainment Scale (GAS). DISCUSSION: This series suggests that risdiplam is safe and may be effective in non-sitter SMA patients older than 16 years of age. In these patients, functional scales and the GAS would be more sensitive than motor scales to detect changes, because they include axial, bulbar, and respiratory domains. Larger studies are needed to confirm these results.

A novel TRMT5 mutation causes a complex inherited neuropathy syndrome: The role of nerve pathology in defining a demyelinating neuropathy.

AIMS: We aim to present data obtained from three patients belonging to three unrelated families with an infantile onset demyelinating neuropathy associated to somatic and neurodevelopmental delay and to describe the underlying genetic changes. METHODS: We performed whole-exome sequencing on genomic DNA from the patients and their parents and reviewed the clinical, muscle and nerve data, the serial neurophysiological studies, brain and muscle MRIs, as well as the respiratory chain complex activity in the muscle of the three index patients. Computer modelling was used to characterise the new missense variant detected. RESULTS: All three patients had a short stature, delayed motor milestone acquisition, intellectual disability and cerebellar abnormalities associated with a severe demyelinating neuropathy, with distinct morphological features. Despite the proliferation of giant mitochondria, the mitochondrial respiratory chain complex activity in skeletal muscle was normal, except in one patient in whom there was a mild decrease in complex I enzyme activity. All three patients carried the same two compound heterozygous variants of the TRMT5 (tRNA Methyltransferase 5) gene, one known pathogenic frameshift mutation [c.312_315del (p.Ile105Serfs*4)] and a second rare missense change [c.665 T > C (p.Ile222Thr)]. TRMT5 is a nuclear-encoded protein involved in the post-transcriptional maturation of mitochondrial tRNA. Computer modelling of the human TRMT5 protein structure suggests that the rare p.Ile222Thr mutation could affect the stability of tRNA binding. CONCLUSIONS: Our study expands the phenotype of mitochondrial disorders caused by TRTM5 mutations and defines a new form of recessive demyelinating peripheral neuropathy.

Characterizing SOD1 mutations in Spain. The impact of genotype, age, and sex in the natural history of the disease.

INTRODUCTION: The aim of this study is to describe the frequency and distribution of SOD1 mutations in Spain, and to explore those factors contributing to their phenotype and prognosis. METHODS: Seventeen centres shared data on amyotrophic lateral sclerosis (ALS) patients carrying pathogenic or likely pathogenic SOD1 variants. Multivariable models were used to explore prognostic modifiers. RESULTS: In 144 patients (from 88 families), 29 mutations (26 missense, 2 deletion/insertion and 1 frameshift) were found in all 5 exons of SOD1, including 7 novel mutations. 2.6% of ALS patients (including 17.7% familial and 1.3% sporadic) were estimated to carry SOD1 mutations. Its frequency varied considerably between regions, due to founder events. The most frequent mutation was p.Gly38Arg (n = 58), followed by p.Glu22Gly (n = 11), p.Asn140His (n = 10), and the novel p.Leu120Val (n = 10). Most mutations were characterized by a protracted course, and some of them by atypical phenotypes. Older age of onset was independently associated with faster disease progression (exp(Estimate) = 1.03 [0.01, 0.05], p = 0.001) and poorer survival (HR = 1.05 [1.01, 1.08], p = 0.007), regardless of the underlying mutation. Female sex was independently associated to faster disease progression (exp(Estimate) = 2.1 [1.23, 3.65], p = 0.012) in patients carrying the p.Gly38Arg mutation, resulting in shorter survival compared with male carriers (236 vs 301 months). CONCLUSIONS: These data may help to evaluate the efficacy of SOD1 targeted treatments, and to expand the number of patients that might benefit from these treatments.

Validation of motor and functional scales for the evaluation of adult patients with 5q spinal muscular atrophy.

BACKGROUND AND PURPOSE: Mos scales currently used to evaluate spinal muscular atrophy (SMA) patients have only been validated in children. The aim of this study was to assess the construct validity and responsiveness of several outcome measures in adult SMA patients. METHODS: Patients older than 15 years and followed up in five referral centres for at least 6 months, between October 2015 and August 2020, with a motor function scale score (Hammersmith Functional Motor Scale Expanded [HFMSE], Revised Upper Limb module [RULM]) were included. Bedside functional scales (Egen Klassification [EK2], Revised Amyotrophic Lateral Sclerosis Functional Rating Scale [ALSFRS-R]) were also collected when available. Spearman's rho correlations (rs) and Bangdiwala's concordance test (B) were used to evaluate the scales' construct validity. Monthly slopes of change were used to calculate their responsiveness of the scales. RESULTS: The study included 79 SMA patients, followed up for a mean of 16 months. All scales showed strong correlations with each other (rs > 0.70). A floor effect in motor function scales was found in the weakest patients (HFMSE < 5 and RULM < 10), and a ceiling effect was found in stronger patients (HFMSE > 60 and RULM > 35). The ALSFRS-R (B = 0.72) showed a strong ability to discriminate between walkers, sitters and non-sitters, and the HFMSE (B = 0.86) between walkers and sitters. The responsiveness was low overall, although in treated patients a moderate responsiveness was found for the ALSFRS-R and HFMSE in walkers (0.69 and 0.61, respectively) and for EK2 in sitters (0.65) and non-sitters (0.60). CONCLUSIONS: This study shows the validity and limitations of the scales most frequently used to assess adult SMA patients. Overall, bedside functional scales showed some advantages over motor scales, although all showed limited responsiveness.

Nusinersen in adult patients with 5q spinal muscular atrophy: A multicenter observational cohorts' study.

BACKGROUND AND PURPOSE: The aim was to assess the safety and efficacy of nusinersen in adult 5q spinal muscular atrophy (SMA) patients. METHODS: Patients older than 15 years and followed for at least 6 months with one motor scale (Hammersmith Functional Motor Scale Expanded, HFMSE; Revised Upper Limb Module, RULM) in five referral centers were included. The clinical and patients' global impression of change (CGI-C and PGI-C) were recorded in treated patients at the last visit. Functional scales (Egen Klassification, EK2; Revised Amyotrophic Lateral Sclerosis Functional Rating Scale, ALSFRS-R) and the percentage predicted forced vital capacity were collected when available. RESULTS: Seventy-nine SMA patients (39 treated with nusinersen) were included. Compared with untreated patients, treated patients showed a significant improvement of 2 points (±0.46) in RULM (p < 0.001) after 6 months. After a mean follow-up of 16 months, nusinersen treatment was associated with a significant improvement in HFMSE (odds ratio [OR] 1.15, p = 0.006), the 6-min walk test (OR = 1.07, p < 0.001) and the EK2 (OR = 0.81, p = 0.001). Compared with untreated patients, more treated patients experienced clinically meaningful improvements in all scales, but these differences were statistically significant only for RULM (p = 0.033), ALSFRS-R (p = 0.005) and EK2 (p < 0.001). According to the CGI-C and PGI-C, 64.1% and 61.5% of treated patients improved with treatment. Being a non-sitter was associated with less response to treatment, whilst a longer time of treatment was associated with better response. Most treated patients (77%) presented at least one adverse event, mostly mild. CONCLUSIONS: Nusinersen treatment is associated with some improvements in adult SMA patients. Most severely affected patients with complex spines are probably those with the most unfavorable risk-benefit ratio.

Charcot-Marie-Tooth disease due to MORC2 mutations in Spain.

BACKGROUND AND PURPOSE: MORC2 mutations have been described as a rare cause of axonal Charcot-Marie-Tooth disease (CMT2Z). The aim of this work was to determine the frequency and distribution of these mutations throughout Spain, to provide a comprehensive phenotypical description and, if possible, to establish a genotype-phenotype correlation. METHODS: Retrospectively, data on patients diagnosed with CMT2Z in Spain were collected and clinical, electrophysiological and muscle imaging information were analysed. RESULTS: Fifteen patients with CMT2Z were identified throughout Spain, seven of them belonging to a single kindred, whilst the rest were sporadic. The most common mutation was p.R252W, and four new mutations were identified. Eleven patients were categorized as having a scapuloperoneal phenotype, with asymmetric muscle weakness, early proximal upper limb involvement and frequent spontaneous muscular activity with distal sensory impairment and pes cavus, whilst two presented with a more classic length dependent sensory motor phenotype. This distinction was corroborated by the distribution of muscle fatty infiltration in muscle imaging. Two other patients were classified as having a neurodevelopmental phenotype consisting in congenital or early onset, delay in motor milestones, and global developmental delay in one of them. Nerve conduction studies revealed an unequivocally axonal neuropathy with frequent spontaneous activity, and serum creatine kinase levels were increased in 50% of the patients. CONCLUSIONS: MORC2 mutations are a rare cause of CMT in Spain, but in-depth phenotyping reveals a recognizable phenotypic spectrum that will be clinically relevant for future identification of this disease.

A study of the phenotypic variability and disease progression in Laing myopathy through the evaluation of muscle imaging.

BACKGROUND: Laing myopathy is characterized by broad clinical and pathological variability. They are limited in number and protocol of study. We aimed to delineate muscle imaging profiles and validate imaging analysis as an outcome measure. METHODS: This was a cross-sectional and longitudinal cohort study. Data from clinical, functional and semi-quantitative muscle imaging (60 magnetic resonance imaging [MRI] and six computed tomography scans) were studied. Hierarchical analysis, graphic heatmap representation and correlation between imaging and clinical data using Bayesian statistics were carried out. RESULTS: The study cohort comprised 42 patients from 13 families harbouring five MYH7 mutations. The cohort had a wide range of ages, age at onset, disease duration, and myopathy extension and Gardner-Medwin and Walton (GMW) functional scores. Intramuscular fat was evident in all but two asymptomatic/pauci-symptomatic patients. Anterior leg compartment muscles were the only affected muscles in 12% of the patients. Widespread extension to the thigh, hip, paravertebral and calf muscles and, less frequently, the scapulohumeral muscles was commonly observed, depicting distinct patterns and rates of progression. Foot muscles were involved in 40% of patients, evolving in parallel to other regions with absence of a disto-proximal gradient. Whole cumulative imaging score, ranging from 0 to 2.9 out of 4, was associated with disease duration and with myopathy extension and GMW scales. Follow-up MRI studies in 24 patients showed significant score progression at a variable rate. CONCLUSIONS: We confirmed that the anterior leg compartment is systematically affected in Laing myopathy and may represent the only manifestation of this disorder. However, widespread muscle involvement in preferential but variable and not distance-dependent patterns was frequently observed. Imaging score analysis is useful to categorize patients and to follow disease progression over time.

Distal hereditary motor neuropathies: Mutation spectrum and genotype-phenotype correlation.

BACKGROUND AND PURPOSE: Distal hereditary motor neuropathies (dHMNs) are a heterogeneous group of disorders characterized by degeneration of the motor component of peripheral nerves. Currently, only 15% to 32.5% of patients with dHMN are characterized genetically. Additionally, the prevalence of these genetic disorders is not well known. Recently, biallelic mutations in the sorbitol dehydrogenase gene (SORD) have been identified as a cause of dHMN, with an estimated frequency in undiagnosed cases of up to 10%. METHODS: In the present study, we included 163 patients belonging to 108 different families who were diagnosed with a dHMN and who underwent a thorough genetic screening that included next-generation sequencing and subsequent Sanger sequencing of SORD. RESULTS: Most probands were sporadic cases (62.3%), and the most frequent age of onset of symptoms was 2 to 10 years (28.8%). A genetic diagnosis was achieved in 37/108 (34.2%) families and 78/163 (47.8%) of all patients. The most frequent cause of distal hereditary motor neuropathies were mutations in HSPB1 (10.4%), GARS1 (9.8%), BICD2 (8.0%), and DNAJB2 (6.7%) genes. In addition, 3.1% of patients were found to be carriers of biallelic mutations in SORD. Mutations in another seven genes were also identified, although they were much less frequent. Eight new pathogenic mutations were detected, and 17 patients without a definite genetic diagnosis carried variants of uncertain significance. The calculated minimum prevalence of dHMN was 2.3 per 100,000 individuals. CONCLUSIONS: This study confirms the genetic heterogeneity of dHMN and that biallelic SORD mutations are a cause of dHMN in different populations.

Quantitative neuromuscular ultrasound analysis as biomarkers in amyotrophic lateral sclerosis.

OBJECTIVES: To assess the differences in morphological and texture parameters of median nerve (MN) and abductor pollicis brevis (APB) between amyotrophic lateral sclerosis (ALS) patients and controls. METHODS: The cross-sectional area (CSA) of the MN and the muscle thickness (MTh) of APB were measured bilaterally in 59 recently diagnosed ALS patients and 20 matched healthy controls. Echointensity (EI), echovariation (EV) and grey-level co-occurrence matrix (GLCM) texture features of both structures were also analysed. Correlations between these parameters and clinical variables (muscle strength and disability) were analysed. RESULTS: The CSA of MN was significantly lower in ALS patients (MD = - 1.83 mm2 [95% CI = 2.89; - 0.77 mm2]; p = 0.01). ALS patients showed significantly lower MTh (- 2.23 mm [3.16; - 1.30 mm]; p < 0.001) and EV (- 7.40 [11.5; - 3.33]; p = 0.004) and higher EI (21.2 [11.9; 30.6]; p < 0.001) in the APB muscle. No relevant differences were detected in GLCM features for this muscle. The model including all parameters (CSA for MN and MTh, EI and EV for APB) showed an AUC of 82% (sensitivity 87%; specificity 42%). Muscle strength and disability correlated with APB muscle ultrasound parameters but not with those of the MN. CONCLUSIONS: APB muscle ultrasound biomarkers (especially MTh and EI) showed better discrimination capacity and correlation with clinical variables than MN biomarkers. However, the combination of both biomarkers increased their ability to detect LMN impairment, suggesting that both biomarkers could be used in a complementary manner for the diagnosis and progression monitoring in ALS. KEY POINTS: • Abductor pollicis brevis muscle and median nerve impairment is detectable by ultrasound in amyotrophic lateral sclerosis patients, even in those without clinical impairment. • Muscle ultrasound biomarkers show better discrimination capacity than nerve biomarkers in amyotrophic lateral sclerosis. • Quantitative neuromuscular ultrasound biomarkers could be useful in a general amyotrophic lateral sclerosis population early on the disease.

The width of the third ventricle associates with cognition and behaviour in motor neuron disease.

OBJECTIVES: An enlarged width of the third ventricle (WTV) has been described in amyotrophic lateral sclerosis (ALS) patients, although its clinical meaning is unknown. The aims of this study were to evaluate the contribution of demographical, clinical and genetic factors to the WTV in different motor neuron disease (MND) phenotypes and to assess its brain structural correlates. MATERIALS AND METHODS: The WTV was measured by transcranial ultrasound in 107 MND patients (82 diagnosed with classical ALS, 16 with progressive muscular atrophy and 9 with primary lateral sclerosis) and 25 controls. Genetic analysis, and neurological and neuropsychological examinations were performed in patients. Brain volumetric analysis of MR images was obtained in 85 patients. The association of WTV with demographical, clinical, genetic and neuropsychological variables as well as with brain volumes was assessed by multivariable models. RESULTS: Eighteen patients were diagnosed with genetic MND and 42.3% of patients showed executive or behavioural impairment (EBI). MND patients showed larger WTV than controls. The WTV was significantly associated with age, spinal onset and the presence of EBI, but not with the genetic background, the phenotype or disability. Greater WTV was also associated with reduced subcortical grey matter volume, but not with the cortical or the white matter volume. CONCLUSIONS: The enlargement of the WTV found in the different MND phenotypes is attributable to the subcortical grey matter atrophy and is associated with cognitive and behavioural impairment. Larger longitudinal studies are needed to determine its role as biomarker in MND patients with frontotemporal dementia.

Characterising the phenotype and mode of inheritance of patients with inherited peripheral neuropathies carrying MME mutations.

BACKGROUND: Mutations in the metalloendopeptidase (MME) gene were initially identified as a cause of autosomal recessive Charcot-Marie-Tooth disease type 2 (CMT2). Subsequently, variants in MME were linked to other late-onset autosomal dominant polyneuropathies. Thus, our goal was to define the phenotype and mode of inheritance of patients carrying changes in MME. METHODS: We screened 197 index cases with a hereditary neuropathy of the CMT type or distal hereditary motor neuropathy (dHMN) and 10 probands with familial amyotrophic lateral sclerosis (fALS) using a custom panel of 119 genes. In addition to the index case subjects, we also studied other clinically and/or genetically affected and unaffected family members. RESULTS: We found 17 variants in MME in a total of 20 index cases, with biallelic MME mutations detected in 13 cases from nine families (three in homozygosis and six in compound heterozygosis) and heterozygous variants found in 11 families. All patients with biallelic variants had a similar phenotype, consistent with late-onset axonal neuropathy. Conversely, the phenotype of patients carrying heterozygous mutations was highly variable [CMT type 1 (CMT1), CMT2, dHMN and fALS] and mutations did not segregate with the disease. CONCLUSION: MME mutations that segregate in an autosomal recessive pattern are associated with a late-onset CMT2 phenotype, yet we could not demonstrate that MME variants in heterozygosis cause neuropathy. Our data highlight the importance of establishing an accurate genetic diagnosis in patients carrying MME mutations, especially with a view to genetic counselling.

Brain signal intensity changes as biomarkers in amyotrophic lateral sclerosis.

OBJECTIVES: To evaluate the contribution of the demographical, clinical, analytical and genetic factors to brain signal intensity changes in T2-weighted MR images in amyotrophic lateral sclerosis (ALS) patients and controls. METHODS: Susceptibility-weighted and FLAIR sequences were obtained in a 3T MR scanner. Iron-related hypointensities in the motor cortex (IRhMC) and hyperintensities of the corticospinal tract (HCT) were qualitatively scored. Age, gender, family history and clinical variables were recorded. Baseline levels of ferritin were measured. C9orf72 was tested in all patients and SOD1 only in familial ALS patients not carrying a C9orf72 expansion. Patients who carried a mutation were categorized as genetic. Associations of these variables with visual scores were assessed with multivariable analysis. RESULTS: A total of 102 ALS patients (92 non-genetic and 10 genetic) and 48 controls (28 ALS mimics and 20 healthy controls) were recruited. In controls, IRhMC associated with age, but HCT did not. In ALS patients, both HTC and IRhMC strongly associated with clinical UMN impairment and bulbar onset. The intensity/extent of IRhMC in the different motor homunculus regions (lower limbs, upper limbs and bulbar) were linked to the symptoms onset site. Between genetic and sporadic patients, no difference in IRhMC and HCT was found. CONCLUSIONS: IRhMC and HCT are reliable markers of UMN degeneration in ALS patients and are more frequent in bulbar onset patients, independently of the mutation status. Age should be considered when evaluating IRhMC. The regional measurement of IRhMC following the motor homunculus could be used as a measure of disease progression.

Urodynamic findings in amyotrophic lateral sclerosis patients with lower urinary tract symptoms: Results from a pilot study.

AIMS: To determine lower urinary tract symptoms (LUTS) prevalence and urodynamic findings in amyotrophic lateral sclerosis (ALS) patients treated in our hospital. METHODS: Cross-sectional and descriptive study on a cohort of ALS patients. Validated questionnaires (ICIQ-SF, IPSS, and OAB-V8) were self-administered in order to evaluate the presence of LUTS. Symptoms were classified as clinically significant (csLUTS), if any of following scores, IPSS > 7, ICIQ-SF > 0, or OAB-V8 ≥ 8, were present. Urodynamic study was offered to csLUTS patients. Physical examination and prostate ultrasound were also performed. RESULTS: Fifty five of seventy nine (70%) ALS patients accepted to participate in the study. Only 24/55 (43.6%) patients met criteria for csLUTS and 13 patients reported urgency urinary incontinence (26.3%). Most of csLUTS patients complained of mixed symptoms (82.6%). QoL measured by IPSS was 2.1 ± 1.5, 20% scoring as mostly dissatisfied or unhappy. Average QoL ICIQ-SF scoring was 3.17 ± 3, 33% complained of moderate to severe bother. Ten of twenty four (41.7%) csLUTS patients consented to UDS. The most frequent finding was detrusor overactivity with obstruction due to non-relaxing external sphincter (five patients) or bladder neck (two patients). Two patients showed normal bladder filling but non-relaxing external sphincter during voiding. UDS was normal in one patient. CONCLUSIONS: In this small pilot study we found a high prevalence of csLUTS in ALS which are mainly related to a combination of voiding and storage symptoms. In most patients, symptoms are caused by overactive detrusor combined with non-relaxing sphincter. Severity of symptoms and impact in QoL is only moderate but in a subset of patients can be considerable. Neurourol. Urodynam. 36:626-631, 2017. © 2016 Wiley Periodicals, Inc.

Quantitative Muscle Ultrasonography Using Textural Analysis in Amyotrophic Lateral Sclerosis.

The purpose of this study was to analyze differences in gray-level co-occurrence matrix (GLCM) parameters, as assessed by muscle ultrasound (MUS), between amyotrophic lateral sclerosis (ALS) patients and healthy controls, and to compare the diagnostic accuracy of these GLCM parameters with first-order MUS parameters (echointensity [EI], echovariation [EV], and muscle thickness [MTh]) in different muscle groups. Twenty-six patients with ALS and 26 healthy subjects underwent bilateral and transverse ultrasound of the biceps/brachialis, forearm flexor, quadriceps femoris, and tibialis anterior muscle groups. MTh was measured with electronic calipers, and EI, EV, and GLCM were obtained using Image J (v.1.48) software. Sensitivity, specificity, likelihood ratios, and area under the curve (AUC) were performed by logistic regression models and receiver operating characteristic curves. GLCM parameters showed reduced granularity in the muscles of ALS patients compared with the controls. Regarding the discrimination capacity, the best single diagnostic parameter in forearm flexors and quadriceps was GLCM and in biceps brachialis and tibialis anterior was EV. The respective combination of these two parameters with MTh resulted in the best AUC (over 90% in all muscle groups and close to the maximum combination model). The use of new textural parameters (EV and GLCM) combined with usual quantitative MUS variables is a promising biomarker in ALS.

Design and Validation of a Clinical Outcome Measure for Adolescents and Adult Patients with Spinal Muscular Atrophy: SMA Life Study Protocol.

INTRODUCTION: The objective of this study is to develop a clinical tool for the evaluation and follow-up of adolescent and adult patients with 5q spinal muscular atrophy (SMA) and to design its validation. METHODS: This prospective, non-interventional study will be carried out at five centres in Spain and will include patients aged 16 years or older with a confirmed diagnosis of 5q SMA (biallelic mutation of the survival motor neuron 1 [SMN1] gene). A panel of experts made up of neurologists, physiatrists and Spanish patients' association (FundAME), participated in the design of the clinical tool. Physicians will administer the tool at three time points (baseline, 12 months and 24 months). Additionally, data from other questionnaires and scales will be collected. Once recruitment is achieved, an interim statistical analysis will be performed to assess its psychometric properties by applying Rasch analysis and classical statistical tests. RESULTS: The tool will consist of up to 53 items to assess functional status from a clinical perspective in seven key dimensions (bulbar, respiratory, axial, lower, upper, fatigability and other symptoms), which will be collected together with objective clinical measures (body mass index, forced vital capacity, pinch strength and 6-minute walk test). CONCLUSIONS: The validation of this tool will facilitate the clinical evaluation of adult and adolescent patients with SMA and the quantification of their response to new treatments in both clinical practice and research.

Spinal Muscular Atrophy Update in Best Practices: Recommendations for Diagnosis Considerations.

Background and Objectives: Spinal muscular atrophy (SMA) is an autosomal recessive progressive neurodegenerative primary motor neuron disorder caused by biallelic variants of the survival motor neuron 1 (SMN1) gene. The most recent SMA best practice recommendations were published in 2018 shortly after the approval of the first SMN-enhancing treatment. The availability of disease-modifying therapies for 5q SMA and implementation of SMA newborn screening (NBS) has led to urgency to update the SMA best practice recommendations for diagnosis and to reevaluate the current classification of SMA. In addition, the availability of disease-modifying therapies has opened the door to explore improved diagnosis of adult-onset SMA. Methods: A systematic literature review was conducted on SMA NBS. An SMA working group of American and European health care providers developed recommendations through a modified Delphi technique with serial surveys and virtual meeting feedback on SMA diagnosis to fill information gaps for topics with limited evidence. A community working group of an individual with SMA and caregivers provided insight and perspective on SMA diagnosis and support through a virtual meeting to guide recommendations. Results: The health care provider working group achieved consensus that SMA NBS is essential to include in the updated best practice for SMA diagnosis (100%). Recommendations for the following are described: characterizing NBS-identified infants before treatment; minimum recommendations for starting or offering SMA NBS in a state or country; recommendations for activities and services to be provided by an SMA specialty care center accepting SMA NBS referrals; and recommendations for partnership with individuals with SMA and caregivers to support NBS-identified infants and their caregivers. Limited data are available to advance efficient diagnosis of adult-onset SMA. Discussion: Updating best practice recommendations for SMA diagnosis to include SMA NBS implementation is essential to advancing care for individuals with SMA. In addition to testing, processes for the efficient management of positive newborn screen with access to knowledgeable and skilled health care providers and access to treatment options is critical to successful early diagnosis. Additional evidence is required to improve adult-onset SMA diagnosis.