Atorvastatin Effect on Aortic Dilatation and Valvular Calcification Progression in Bicuspid Aortic Valve (BICATOR): A Randomized Clinical Trial.

BACKGROUND: Ascending aorta dilation and aortic valve degeneration are common complications in patients with bicuspid aortic valve. Several retrospective studies have suggested the benefit of statins in reducing these complications. This study aimed to determine whether atorvastatin treatment is effective in reducing the growth of aortic diameters in bicuspid aortic valve and if it slows the progression of valve calcification. METHODS: In a randomized clinical trial, 220 patients with bicuspid aortic valve (43 women; 46±13 years of age) were included and treated with either 20 mg of atorvastatin per day or placebo for 3 years. Inclusion criteria were ≥18 years of age, nonsevere valvular dysfunction, nonsevere valve calcification, and ascending aorta diameter ≤50 mm. Computed tomography and echocardiography studies were performed at baseline and after 3 years of treatment. RESULTS: During follow-up, 28 patients (12.7%) discontinued medical treatment (15 on atorvastatin and 13 taking placebo). Thus, 192 patients completed the 36 months of treatment. Low-density lipoprotein cholesterol levels decreased significantly in the atorvastatin group (median [interquartile range], -30 mg/dL [-51.65 to -1.75 mg/dL] versus 6 mg/dL [-4, 22.5 mg/dL]; P<0.001). The maximum ascending aorta diameter increased with no differences between groups: 0.65 mm (95% CI, 0.45-0.85) in the atorvastatin group and 0.74 mm (95% CI, 0.45-1.04) in the placebo group (P=0.613). Similarly, no significant differences were found for the progression of the aortic valve calcium score (P=0.167) or valvular dysfunction. CONCLUSIONS: Among patients with bicuspid aortic valve without severe valvular dysfunction, atorvastatin treatment was not effective in reducing the progression of ascending aorta dilation and aortic valve calcification during 3 years of treatment despite a significant reduction in low-density lipoprotein cholesterol levels. REGISTRATION: URL: https://www.clinicaltrialsregister.eu; Unique identifier: 2015-001808-57. URL: https://www.clinicaltrials.gov; Unique identifier: NCT02679261.

Different prognostic significance of coronary artery and aortic valve calcium in patients with chest pain.

OBJECTIVES: Coronary artery calcification (CorCa) identifies high cardiovascular risk in the general population. In this setting, aortic valve calcification (AoCa) showed contradictory results. Our goal has been to assess the prognostic power of CorCa and AoCa in patients with chest pain who underwent an ECG-gated cardiac multidetector CT (cardiac-MDCT). METHODS: A total of 528 patients without previous known coronary artery disease, with chest pain who underwent a cardiac-MDCT multidetector, were retrospectively recruited. The primary endpoint included death, acute coronary syndrome, stroke, and heart failure. RESULTS: A total of 61 patients (11.6%) had an event during a mean follow-up of almost 6 years (5.95 ± 2.98). The most frequent event was acute coronary syndrome (6.4%). Total mortality was 4.5%. Patients with CorCa > 0 had more events than those without CorCa (17.3% versus 4.3%; p < 0.001). Likewise, when only patients without AoCa were considered (n = 118), clinical events were more frequent in those with CorCa (12.7% versus 3.6%; p = 0.004). After excluding patients with coronary artery disease, events were more frequent in those with CorCa (12.6% versus 4.3%; p = 0.004). The higher the Agatston score, the more frequent the events. Patients with AoCa > 0 had more events than those without (16.5% versus 7.3%; p < 0.001), but in patients without CorCa, no difference in events was seen (6.2% versus 3.6%; p = 0.471). A Cox regression analysis showed age, smoking, prior stroke, and CorCa but not AoCa to be independently related to events. CONCLUSIONS: In summary, CorCa, but not AoCa, is related to cardiovascular events in patients with chest pain who undergo a cardiac-MDCT. CLINICAL RELEVANCE STATEMENT: We show that coronary artery calcification, but not aortic valve calcification, detected in a coronary CT scan is tightly related to cardiovascular events. Although this is a message already shown by other groups in the general population, we do believe that this work is unique because it is restricted to patients with chest pain sent to coronary CT. In other words, our work deals with what we face in our routine everyday practice. KEY POINTS: • The presence and the amount of coronary artery calcification are associated with cardiovascular events in patients with chest pain. • Aortic valve calcification is not associated with cardiovascular events in patients with chest pain.

Prognostic value of novel cardiovascular magnetic resonance transit times beyond the pulmonary circulation in patients with ventricular dysfunction.

OBJECTIVES: To evaluate the prognostic value of transit time (TT) assessment in the systemic circulation and organ perfusion in patients with ventricular dysfunction (VD). The primary endpoint was defined as death, heart failure admission, or ventricular arrhythmias, and the secondary endpoint was worsening renal function. METHODS: A retrospective study on 139 patients who underwent cardiac magnetic resonance for VD evaluation and 50 controls. TT was measured as peak-to-peak time in signal intensity over time curves obtained at different stages of circulation (right cavities, left cavities, aorta, and peripheral organs) from first-pass perfusion images. Outcomes were monitored over a median follow-up of 15 months. RESULTS: A total of 139 patients were included (84% male, age 63 [57-70] years). Patients exhibited significantly prolonged TT compared to controls, with in-patients showing longer times than outpatients. Among the 29 patients reaching the primary endpoint, both PTT and STT were significantly prolonged (PTT: 9.75 s vs 13.4 s, p < 0.01; STT: 4.77 s vs 7.00 s, p < 0.01). Concurrent prolongation of PTT (> 10 s) and STT (> 5 s) was associated with a higher event probability (42.3%), compared to isolated abnormalities (6.3% for PTT, 6.7% for STT). Multivariate analysis revealed that combined PTT and STT alteration independently predicted the combined endpoint (HR IC 95%: 8.685 (2.415-31.236), p = 0.001). Prolonged RPT was independently associated with renal function deterioration (OR IC 95%: 1.129 (1.015-1.256), p = 0.024). CONCLUSIONS: Evaluation of TT beyond pulmonary circulation provides prognostic insights into VD. Simultaneous assessment of PTT and STT enhances specificity compared to isolated PTT evaluation, predicting combined adverse events. RPT is independently associated with renal impairment. CLINICAL RELEVANCE STATEMENT: For the first time, it is described that transit time can be evaluated in systemic circulation and in peripheral organs and that this assessment can be easily made from conventional CMR perfusion images and holds significant prognostic value. KEY POINTS: Pulmonary transit time is a valuable hemodynamic parameter; systemic transit time may also be valuable. Transit time can be measured in the systemic circulation, and is longer in patients with ventricular dysfunction. Systemic transit time assessed by magnetic resonance imaging identifies patients with ventricular dysfunction who will experience events during follow-up.

Impact of SARS-CoV-2 infection and COVID-19 pandemic on the morbidity and mortality of amyotrophic lateral sclerosis patients in Valencia, Spain.

BACKGROUND AND PURPOSE: The purpose was to describe the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, hospitalization for coronavirus disease 2019 (COVID-19) and related death and to assess the impact of the pandemic in the survival of amyotrophic lateral sclerosis (ALS) patients. METHODS: The risk of SARS-CoV-2 infection, hospitalization for COVID-19 and related death was assessed in ALS patients alive between March 2020 and July 2022. To evaluate its impact in the overall survival of ALS patients, the survival of patients who died before and during the pandemic was compared. RESULTS: Amongst 263 ALS patients alive during the pandemic, 62 got infected during the study period (infection rate 14.34 per 100 person-years). Most infections (68%) occurred during the sixth wave (November 2021 to January 2022) and most patients (67%) were vaccinated at the time of infection. The hospitalization rate due to COVID-19 was 4.16 per 100 person-years. The multivariable model confirmed non-invasive ventilation (NIV) use prior to infection as a risk factor for hospitalization (odds ratio [OR] = 7.96, p = 0.003) and COVID-19 vaccination as a protective factor (OR = 0.093, p = 0.025) independent of age, sex and gastrostomy. Within 30 days after infection, 7% of non-ventilated patients started NIV and five patients (8.06%) died, of whom four were previously ventilated. The median survival of ALS patients was similar before and during the pandemic and no effect was found in the Cox regression model (hazard ratio 1.02, p = 0.89). CONCLUSIONS: This study shows a high risk of severe COVID-19 amongst ALS patients requiring NIV. Nevertheless, the pandemic showed no impact in the overall survival of ALS patients, probably due to a high vaccination rate and an adequate access to healthcare resources.

ITPR3-associated neuropathy: Report of a further family with adult onset intermediate Charcot-Marie-Tooth disease.

BACKGROUND AND PURPOSE: ITPR3 encodes type 3 inositol-tri-phosphate receptor (IP3R3), a protein expressed in Schwann cells, predominantly in the paranodal region, and involved in the regulation of Ca2+ release from the endoplasmic reticulum. Dominant variants in ITPR3 have recently been recognized as a rare cause of intermediate Charcot-Marie-Tooth disease (CMT). METHODS: We collected the clinical data of a family with autosomal dominant neuropathy whose proband was diagnosed with chronic inflammatory demyelinating polyneuropathy (CIDP) for many years. The genetic diagnosis was achieved by whole exome sequencing. RESULTS: The proband developed symmetrical sensory-motor neuropathy with demyelinating features at 32 years old. He was diagnosed with CIDP and received numerous immunomodulatory treatments. However, his condition progressed, leading to severe proximal leg and hand atrophy that confined him to a wheelchair at 60 years. The patient's two sons began to exhibit symptoms suggestive of neuropathy shortly after age 30 years, and the condition was reoriented as inherited. Exome sequencing identified a heterozygous c.4271C > T variant in the ITPR3 gene segregating with the disease. Nerve conduction studies showed a combination of demyelinating and axonal features that vary by nerve, disease duration, and patient. A uniform thickening of the nerves was identified on nerve echography, as was distal symmetric fatty infiltration in lower limb muscle imaging. CONCLUSIONS: The c.4271C > T ITPR3 variant causes a late onset CMT that can be considered an intermediate CMT. Considering the electrophysiological findings and the distribution of IP3R3, we hypothesize that this variant could start as nodal dysfunction that progresses to widespread nerve degeneration.

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.

Therapeutic potential of oleic acid supplementation in myotonic dystrophy muscle cell models.

BACKGROUND: We recently reported that upregulation of Musashi 2 (MSI2) protein in the rare neuromuscular disease myotonic dystrophy type 1 contributes to the hyperactivation of the muscle catabolic processes autophagy and UPS through a reduction in miR-7 levels. Because oleic acid (OA) is a known allosteric regulator of MSI2 activity in the biogenesis of miR-7, here we sought to evaluate endogenous levels of this fatty acid and its therapeutic potential in rescuing cell differentiation phenotypes in vitro. In this work, four muscle cell lines derived from DM1 patients were treated with OA for 24 h, and autophagy and muscle differentiation parameters were analyzed. RESULTS: We demonstrate a reduction of OA levels in different cell models of the disease. OA supplementation rescued disease-related phenotypes such as fusion index, myotube diameter, and repressed autophagy. This involved inhibiting MSI2 regulation of direct molecular target miR-7 since OA isoschizomer, elaidic acid (EA) could not cause the same rescues. Reduction of OA levels seems to stem from impaired biogenesis since levels of the enzyme stearoyl-CoA desaturase 1 (SCD1), responsible for converting stearic acid to oleic acid, are decreased in DM1 and correlate with OA amounts. CONCLUSIONS: For the first time in DM1, we describe a fatty acid metabolism impairment that originated, at least in part, from a decrease in SCD1. Because OA allosterically inhibits MSI2 binding to molecular targets, reduced OA levels synergize with the overexpression of MSI2 and contribute to the MSI2 > miR-7 > autophagy axis that we proposed to explain the muscle atrophy phenotype.

Dystrophinopathy Phenotypes and Modifying Factors in DMD Exon 45-55 Deletion.

OBJECTIVE: Duchenne muscular dystrophy (DMD) exon 45-55 deletion (del45-55) has been postulated as a model that could treat up to 60% of DMD patients, but the associated clinical variability and complications require clarification. We aimed to understand the phenotypes and potential modifying factors of this dystrophinopathy subset. METHODS: This cross-sectional, multicenter cohort study applied clinical and functional evaluation. Next generation sequencing was employed to identify intronic breakpoints and their impact on the Dp140 promotor, intronic long noncoding RNA, and regulatory splicing sequences. DMD modifiers (SPP1, LTBP4, ACTN3) and concomitant mutations were also assessed. Haplotypes were built using DMD single nucleotide polymorphisms. Dystrophin expression was evaluated via immunostaining, Western blotting, reverse transcription polymerase chain reaction (PCR), and droplet digital PCR in 9 muscle biopsies. RESULTS: The series comprised 57 subjects (23 index) expressing Becker phenotype (28%), isolated cardiopathy (19%), and asymptomatic features (53%). Cognitive impairment occurred in 90% of children. Patients were classified according to 10 distinct index-case breakpoints; 4 of them were recurrent due to founder events. A specific breakpoint (D5) was associated with severity, but no significant effect was appreciated due to the changes in intronic sequences. All biopsies showed dystrophin expression of >67% and traces of alternative del45-57 transcript that were not deemed pathogenically relevant. Only the LTBP4 haplotype appeared associated the presence of cardiopathy among the explored extragenic factors. INTERPRETATION: We confirmed that del45-55 segregates a high proportion of benign phenotypes, severe cases, and isolated cardiac and cognitive presentations. Although some influence of the intronic breakpoint position and the LTBP4 modifier may exist, the pathomechanisms responsible for the phenotypic variability remain largely unresolved. ANN NEUROL 2022;92:793-806.

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.

Hereditary motor neuropathies.

PURPOSE OF REVIEW: Distal hereditary motor neuropathies (dHMN) are a clinically and genetically diverse group of disorders that are characterized by length-dependent axonal degeneration of lower motor neurons. In this review, we will provide an overview of dHMN, and we will correlate the distinct clinical subtypes with their causative genes, focusing on the most recent advances in the field. RECENT FINDINGS: Despite the massive use of new-generation sequencing (NGS) and the discovery of new genes, only a third of dHMN patients receive a molecular diagnosis. Thanks to international cooperation between researchers, new genes have been implicated in dHMN, such as SORD and VWA1 . Mutations in SORD are the most frequent cause of autosomal recessive forms of dHMN. As a result of these findings, the potential benefits of some pharmacological compounds are being studied in cell and animal models, mainly targeting axonal transport and metabolic pathways. SUMMARY: Despite the wide use of NGS, the diagnosis of dHMN remains a challenge. The low prevalence of dHMN makes international cooperation necessary in order to discover new genes and causal mechanisms. Genetic diagnosis of patients and identification of new pathomechanism are essential for the development of therapeutical clinical trials.

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.

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.

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.

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.

Characterization of molecular mechanisms underlying the axonal Charcot-Marie-Tooth neuropathy caused by MORC2 mutations.

Mutations in MORC2 lead to an axonal form of Charcot-Marie-Tooth (CMT) neuropathy type 2Z. To date, 31 families have been described with mutations in MORC2, indicating that this gene is frequently involved in axonal CMT cases. While the genetic data clearly establish the causative role of MORC2 in CMT2Z, the impact of its mutations on neuronal biology and their phenotypic consequences in patients remains to be clarified. We show that the full-length form of MORC2 is highly expressed in both embryonic and adult human neural tissues and that Morc2 expression is dynamically regulated in both the developing and the maturing murine nervous system. To determine the effect of the most common MORC2 mutations, p.S87L and p.R252W, we used several in vitro cell culture paradigms. Both mutations induced transcriptional changes in patient-derived fibroblasts and when expressed in rodent sensory neurons. These changes were more pronounced and accompanied by abnormal axonal morphology, in neurons expressing the MORC2 p.S87L mutation, which is associated with a more severe clinical phenotype. These data provide insight into the neuronal specificity of the mutated MORC2-mediated phenotype and highlight the importance of neuronal cell models to study the pathophysiology of CMT2Z.

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.

Clinical characteristics and outcomes of thymoma-associated myasthenia gravis.

BACKGROUND AND PURPOSE: Prognosis of myasthenia gravis (MG) in patients with thymoma is not well established. Moreover, it is not clear whether thymoma recurrence or unresectable lesions entail a worse prognosis of MG. METHODS: This multicenter study was based on data from a Spanish neurologist-driven MG registry. All patients were aged >18 years at onset and had anti-acetylcholine receptor antibodies. We compared the clinical data of thymomatous and nonthymomatous patients. Prognosis of patients with recurrent or nonresectable thymomas was assessed. RESULTS: We included 964 patients from 15 hospitals; 148 (15.4%) had thymoma-associated MG. Median follow-up time was 4.6 years. At onset, thymoma-associated MG patients were younger (52.0 vs. 60.4 years, p < 0.001), had more generalized symptoms (odds ratio [OR]: 3.02, 95% confidence interval [CI]: 1.95-4.68, p < 0.001) and more severe clinical forms according to the Myasthenia Gravis Foundation of America (MGFA) scale (OR: 1.6, 95% CI: 1.15-2.21, p = 0.005). Disease severity based on MGFA postintervention status (MGFA-PIS) was higher in thymomatous patients at 1 year, 5 years, and the end of follow-up. Treatment refractoriness and mortality were also higher (OR: 2.28, 95% CI: 1.43-3.63, p = 0.001; hazard ratio: 2.46, 95% CI: 1.47-4.14, p = 0.001). Myasthenic symptoms worsened in 13 of 27 patients with recurrences, but differences in long-term severity were not significant. Fifteen thymomatous patients had nonresectable thymomas with worse MGFA-PIS and higher mortality at the end of follow-up. CONCLUSIONS: Thymoma-associated MG patients had more severe myasthenic symptoms and worse prognosis. Thymoma recurrence was frequently associated with transient worsening of MG, but long-term prognosis did not differ from nonrecurrent thymoma. Patients with nonresectable thymoma tended to present severe forms of MG.

Groupwise Non-Rigid Registration with Deep Learning: An Affordable Solution Applied to 2D Cardiac Cine MRI Reconstruction.

Groupwise image (GW) registration is customarily used for subsequent processing in medical imaging. However, it is computationally expensive due to repeated calculation of transformations and gradients. In this paper, we propose a deep learning (DL) architecture that achieves GW elastic registration of a 2D dynamic sequence on an affordable average GPU. Our solution, referred to as dGW, is a simplified version of the well-known U-net. In our GW solution, the image that the other images are registered to, referred to in the paper as template image, is iteratively obtained together with the registered images. Design and evaluation have been carried out using 2D cine cardiac MR slices from 2 databases respectively consisting of 89 and 41 subjects. The first database was used for training and validation with 66.6-33.3% split. The second one was used for validation (50%) and testing (50%). Additional network hyperparameters, which are-in essence-those that control the transformation smoothness degree, are obtained by means of a forward selection procedure. Our results show a 9-fold runtime reduction with respect to an optimization-based implementation; in addition, making use of the well-known structural similarity (SSIM) index we have obtained significative differences with dGW with respect to an alternative DL solution based on Voxelmorph.