A Comparison of Three Electrophysiological Methods for the Assessment of Disease Status in a Mild Spinal Muscular Atrophy Mouse Model
نویسندگان
چکیده
OBJECTIVES There is a need for better, noninvasive quantitative biomarkers for assessing the rate of progression and possible response to therapy in spinal muscular atrophy (SMA). In this study, we compared three electrophysiological measures: compound muscle action potential (CMAP) amplitude, motor unit number estimate (MUNE), and electrical impedance myography (EIM) 50 kHz phase values in a mild mouse model of spinal muscular atrophy, the Smn1c/c mouse. METHODS Smn1c/c mice (N = 11) and wild type (WT) animals (-/-, N = 13) were measured on average triweekly until approximately 1 year of age. Measurements included CMAP, EIM, and MUNE of the gastrocnemius muscle as well as weight and front paw grip strength. At the time of sacrifice at one year, additional analyses were performed on the animals including serum survival motor neuron (SMN) protein levels and muscle fiber size. RESULTS Both EIM 50 kHz phase and CMAP showed strong differences between WT and SMA animals (repeated measures 2-way ANOVA, P<0.0001 for both) whereas MUNE did not. Both body weight and EIM showed differences in the trajectory over time (p<0.001 and p = 0.005, respectively). At the time of sacrifice at one year, EIM values correlated to motor neuron counts in the spinal cord and SMN levels across both groups of animals (r = 0.41, p = 0.047 and r = 0.57, p = 0.003, respectively), while CMAP did not. Motor neuron number in Smn1c/c mice was not significantly reduced compared to WT animals. CONCLUSIONS EIM appears sensitive to muscle status in this mild animal model of SMA. The lack of a reduction in MUNE or motor neuron number but reduced EIM and CMAP values support that much of the pathology in these animals is distal to the cell body, likely at the neuromuscular junction or the muscle itself.
منابع مشابه
Drawing Word co-occurrence map of Spinal Muscular Atrophy disease
Introduction: The purpose of this article is to evaluate the status of articles in the field of Spinal Muscular Atrophy According to the Scientometrics indices Word co-occurrence map of this field . Methods: The present study is an applied one with a quantitative approach and a descriptive approach. It has been done using scientometrics and the co-occurrence words analysis technique. Document...
متن کاملO-27: Preimplantation Genetic Diagnosis in Prevention of Genetic Diseases -Diagnostic of Spinal Muscular Atrophy (SMA)
Background: Preimplantation genetic diagnosis - PGD is currently an established procedure allowing genetic research of oocyte or embryo before implantation to the uterus. Spinal muscular atrophy (SMA) is a neurodegenerative disorder, being the second most common lethal autosomal recessive disease in Caucasians, after cystic fibrosis. There are three clinically different types of which type I (W...
متن کاملامیوتروفیک لترال اسکلروزیس یا بیماری کندی: گزارش یک مورد بیماری
Kennedy's Disease (KD) Bulbar and spinal muscular atrophy (BSMA) is an adult onset, X-linked, recessive disorder caused by expansion of a polymorphic CAG tandem repeat. Because Kennedy’s clinical symptoms overlap with some other neuromuscular disorders such as amyotrophic lateral sclerosis (ALS) or spinal muscular atrophies, KD sometimes is misdiagnosed or left unnoticed. Here we describe a...
متن کاملAssessment of Preimplantation Genetic Diagnosis (PGD) for Childhood-onset Spinal Muscular Atrophy (SMA) Using Duplex Fluorescent PCR
متن کامل
SMN1 and NAIP genes deletions in different types of spinal muscular atrophy in Khuzestan province, Iran
Background: Spinal muscular atrophy (SMA) is the second most common lethal autosomal recessive disease. It is a neuromuscular disorder caused by degenerative of lower motor neurons and occasionally bulbar neurons leading to progressive limb paralysis and muscular atrophy. The SMN1 gene is recognized as a SMA causing gene while NAIP has been characterized as a modifying factor for the clinical ...
متن کامل