Project description:BackgroundSpasticity is a common motor disorder resulting from upper motor neuron lesions. It has a serious influence on an individual's motor function and daily activity. Repetitive peripheral magnetic stimulation (rPMS) is a non-invasive and painless approach developed for therapeutic intervention in clinical rehabilitation. However, the effectiveness of this intervention on spasticity in patients with spastic paralysis remains uncertain.ObjectiveThis study aimed to investigate the effectiveness of rPMS on spasticity, motor function, and activities of daily living in individuals with spastic paralysis.MethodsPubMed, PEDro, Embase, Cochrane Library, and Web of Science were searched for eligible papers with date up to March 31, 2022. Two independent researchers conducted study screening, data extraction, and methodological quality assessment. RCTs that explored the effects of rPMS on spasticity, motor function, and activities of daily living in patients with spastic paralysis were included for review. The Cochrane collaboration tool was used to assess methodological quality. The cumulative effects of available data were processed for a meta-analysis using Reedman software.ResultsEight studies with 297 participants were included. Most of the studies presented low to moderate risk of bias. Compared with the control group, the results showed that rPMS had a significant effect on spasticity (all spasticity outcomes: standardized mean difference [SMD] = -0.55, 95% confidence interval [CI]: -0.94 to -0.16, I 2 = 40%, and P = 0.006, Modified Ashworth Scale: mean difference [MD] = -0.48, 95% CI: -0.82 to -0.14, I 2 = 0%, and P = 0.006), motor function (Fugl-Meyer Assessment: MD = 4.17, 95% CI: 0.89 to 7.46, I 2 = 28%, and P = 0.01), and activities of daily living (Barthel Index: MD = 5.12, 95% CI: 2.58 to 7.67, I 2 = 0%, and P < 0.0001). No side effect was reported.ConclusionThe meta-analysis demonstrated that the evidence supported rPMS in improving spasticity especially for passive muscle properties evaluated with Modified Ashworth Scale/Ashworth Scale, as well as motor function and daily activity of living in individuals with spastic paralysis.Study registrationThe reviewed protocol of this study is registered in the international prospective register of systematic reviews (PROSPERO) (CRD42022322395).Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/#recordDetails, identifier CRD42022322395.
Project description:BackgroundTimothy syndrome (OMIM #601005) is a rare disease caused by variants in the gene CACNA1C. Initially, Timothy syndrome was characterized by a cardiac presentation of long QT syndrome and syndactyly of the fingers and/or toes, all associated with the CACNA1C variant, Gly406Arg. However, subsequent identification of diverse variants in CACNA1C has expanded the clinical spectrum, revealing various cardiac and extra-cardiac manifestations. It remains underexplored whether individuals with the canonical Gly406Arg variants in mutually exclusive exon 8A (Timothy syndrome 1) or exon 8 (Timothy syndrome 2) exhibit overlapping symptoms. Moreover, case reports have indicated that some CACNA1C variants may produce a cardiac-selective form of Timothy syndrome often referred to as non-syndromic long QT type 8 or cardiac-only Timothy syndrome, however few reports follow up on these patients to confirm the cardiac selectivity of the phenotype over time.MethodsA survey was administered to the parents of patients with Timothy syndrome, querying a broad range of symptoms and clinical features. Study participants were organized into 5 separate categories based on genotype and initial diagnosis, enabling comparison between groups of patients which have been described differentially in the literature.ResultsOur findings reveal that Timothy syndrome patients commonly exhibit both cardiac and extra-cardiac features, with long QT syndrome, neurodevelopmental impairments, hypoglycemia, and respiratory issues being frequently reported. Notably, the incidence of these features was similar across all patient categories, including those diagnosed with non-syndromic long QT type 8, suggesting that the 'non-syndromic' classification may be incomplete.ConclusionsThis study represents the first Natural History Study of Timothy syndrome, offering a comprehensive overview of the disease's clinical manifestations. We demonstrate that both cardiac and extra-cardiac features are prevalent across all patient groups, underscoring the syndromic nature of CACNA1C variants. While the critical role of long QT syndrome and cardiac arrhythmias in Timothy syndrome has been well recognized, our findings indicate that hypoglycemia and respiratory dysfunction also pose significant life-threatening risks, emphasizing the need for comprehensive therapeutic management of affected individuals.
Project description:Timothy Syndrome (TS) (OMIM #601005) is a rare autosomal dominant syndrome caused by variants in CACNA1C, which encodes the α1C subunit of the voltage-gated calcium channel Cav1.2. TS is classically caused by only a few different genetic changes and characterized by prolonged QT interval, syndactyly, and neurodevelopmental delay; however, the number of identified TS-causing variants is growing, and the resulting symptom profiles are incredibly complex and variable. Here, we aim to review the genetic and clinical findings of all published case reports of TS to date. We discuss multiple possible mechanisms for the variability seen in clinical features across these cases, including mosaicism, genetic background, isoform complexity of CACNA1C and differential expression of transcripts, and biophysical changes in mutant CACNA1C channels. Finally, we propose future research directions such as variant validation, in vivo modeling, and natural history characterization.
Project description:BackgroundTimothy syndrome (TS) is a disease of excessive cellular Ca(2+) entry and life-threatening arrhythmias caused by a mutation in the primary cardiac L-type Ca(2+) channel (Ca(V)1.2). The TS mutation causes loss of normal voltage-dependent inactivation of Ca(V)1.2 current (I(Ca)). During cellular Ca(2+) overload, the calmodulin-dependent protein kinase II (CaMKII) causes arrhythmias. We hypothesized that CaMKII is a part of the proarrhythmic mechanism in TS.Methods and resultsWe developed an adult rat ventricular myocyte model of TS (G406R) by lentivirus-mediated transfer of wild-type and TS Ca(V)1.2. The exogenous Ca(V)1.2 contained a mutation (T1066Y) conferring dihydropyridine resistance, so we could silence endogenous Ca(V)1.2 with nifedipine and maintain peak I(Ca) at control levels in infected cells. TS Ca(V)1.2-infected ventricular myocytes exhibited the signature voltage-dependent inactivation loss under Ca(2+) buffering conditions, not permissive for CaMKII activation. In physiological Ca(2+) solutions, TS Ca(V)1.2-expressing ventricular myocytes exhibited increased CaMKII activity and a proarrhythmic phenotype that included action potential prolongation, increased I(Ca) facilitation, and afterdepolarizations. Intracellular dialysis of a CaMKII inhibitory peptide, but not a control peptide, reversed increases in I(Ca) facilitation, normalized the action potential, and prevented afterdepolarizations. We developed a revised mathematical model that accounts for CaMKII-dependent and CaMKII-independent effects of the TS mutation.ConclusionsIn TS, the loss of voltage-dependent inactivation is an upstream initiating event for arrhythmia phenotypes that are ultimately dependent on CaMKII activation.