Magnetic Resonance Imaging characteristics in case of TOR1AIP1 muscular dystrophy

Mutations in the torsinA-interacting protein 1 (TOR1AIP1) gene result in a severe muscular dystrophy with minimal literature in the pediatric population. We review a case of TOR1AIP1 gene mutation in a 16-year-old Caucasian female with a long history of muscle weakness. Extensive clinical workup was performed and MRI at time of initial presentation demonstrated no significant muscular atrophy with heterogenous STIR hyperintensity of the lower extremity muscles. MRI findings seven years later included extensive atrophy of the lower extremities, with severe progression, including the gluteal muscles, iliopsoas, rectus femoris, and obturator internus. There was also significant atrophy of the rectus abdominis and internal and external oblique muscles, and iliacus muscles. The MRI findings showed more proximal involvement of lower extremities and no atrophy of the tibialis anterior, making TOR1AIP1 the more likely genetic cause. Muscle biopsy findings supported TOR1AIP1 limb-girdle muscular dystrophy. Though rare, TOR1AIP1 gene mutation occurs in pediatric patients and MRI can aid in diagnosis and help differentiate from other types of muscular dystrophy. Genetic and pathology workup is also crucial to accurate diagnosis and possible treatment of these patients.     

Muscle MRI findings in facioscapulohumeral muscular dystrophy

Objectives

Facioscapulohumeral muscular dystrophy (FSHD) is characterized by extremely variable degrees of facial, scapular and lower limb muscle involvement. Clinical and genetic determination can be difficult, as molecular analysis is not always definitive, and other similar muscle disorders may have overlapping clinical manifestations.

Methods and Materials

Whole-body muscle MRI examination for fat infiltration, atrophy and oedema was performed to identify specific patterns of muscle involvement in FSHD patients (30 subjects), and compared to a group of control patients (23) affected by other myopathies (NFSHD).

Results

In FSHD patients, we detected a specific pattern of muscle fatty replacement and atrophy, particularly in upper girdle muscles. The most frequently affected muscles, including paucisymptomatic and severely affected FSHD patients, were trapezius, teres major and serratus anterior. Moreover, asymmetric muscle involvement was significantly higher in FSHD as compared to NFSHD patients.

Conclusions

In conclusion, muscle MRI is very sensitive for identifying a specific pattern of involvement in FSHD patients and in detecting selective muscle involvement of non-clinically testable muscles. Muscle MRI constitutes a reliable tool for differentiating FSHD from other muscular dystrophies to direct diagnostic molecular analysis, as well as to investigate FSHD natural history and follow-up of the disease.

Key Points

? Muscle MRI identifies a specific pattern of muscle involvement in FSHD patients. ? Muscle MRI may predict FSHD in asymptomatic and severely affected patients. ? Muscle MRI of upper girdle better predicts FSHD. ? Muscle MRI may differentiate FSHD from other forms of muscular dystrophy. ? Muscle MRI may show the involvement of non-clinical testable muscles.

     

Magnetic resonance imaging of primary skeletal muscle diseases: patterns of distribution and severity of involvement

Magnetic resonance imaging of the lower extremities was performed with a low field system in 51 patients representing three different categories of biopsy-proven primary skeletal muscle disease; muscular dystrophies, congenital myopathies and polymyositis. The intermuscular distribution of abnormal signal intensity and the grade of involvement of individual muscles were assessed. Large differences in the degree of pathological signal intensity between individual muscles were found in all categories. In the muscular dystrophy and polymyositis patients, the overall involvement was significantly more severe than in patients with congenital myopathy. Definite patterns of selective involvement were seen. Statistical evidence of selective muscle sparing was found; the gracilis muscle was significantly less affected than the other muscles in all three disease groups. Other muscles with significant sparing include the rectus femoris and sartorius muscles of the thigh and the tibialis posterior muscle of the leg. Common anatomical and functional characteristics of muscles may be related to the distribution of muscular disease.     

MRI在进行性肌营养不良中的应用价值

目的探讨进行性肌营养不良(progressive muscular dystrophy,PMD)的骨骼肌MRI表现与临床的相关性及其应用价值。资料与方法对22例经临床表现、血清肌酸激酶(CPK)、肌电图检查及开放式骨骼肌活检、组织及免疫病理学证实的PMD患者的临床及影像资料进行回顾性分析。结果各型肌病MRI受累肌肉分布特征为:杜兴型和贝克型为大腿前部肌群;肢带型2B型为大腿后部肌群;远端型中Welander型为大腿后部肌群及小腿前群、外侧群肌肉;Nonaka型为小腿前群、外侧群肌肉;Miyoshi型为小腿后部肌群;先天性为大、小腿后部肌群;强直性为大、小腿前、后肌群。MRI上的病变程度与病程无一致性关系。除假肥大型无肌肉水肿表现外,其余类型均有不同程度的肌肉水肿。结论 MRI表现提示不同的肌病类型有特定的分布,有助于临床鉴别某些类型的肌病。利用对脂肪沉积和水肿敏感的MRI序列,有助于理解肌病的病理过程,协助临床检查监测对治疗的反应。     

The clinical and genetic correlates of MRI findings in myotonic dystrophy

Amplification of an unstable CTG trinucleotide repeat sequence in a protein kinase gene on chromosome 19 has recently been recognised as the molecular basis of myotonic dystrophy (DM), a multisystem disorder with a wide spectrum of muscular and extramuscular manifestations. The CTG expansion of 40 patients was assessed by direct genotype analysis of the white blood cell DNA and correlated with MRI of the brain and muscles, and with functional clinical data. Cerebral pathology on MRI consisted of diffuse atrophy (68 %), subcortical white matter lesions (65 %), wide Virchow-Robin spaces (38 %) and thickening of the skull (35 %). Cerebral atrophy and extent of white matter disease correlated significantly with mental retardation, duration of disease and CTG fragment amplification. MRI of the muscular system showed fatty degeneration of different degrees in neighbouring muscles causing a mosaic pattern of the thigh in 38 % and the calf in 44 %. Muscular changes on MRI were strongly correlated with muscular impairment but less strongly with CTG expansion. Changes on MRI reflect the stage of development of tissue pathology in DM, modified by defect of the DM gene. Pathology on MRI is strongly correlated with functional deficits. Received: 12 April 1995 Accepted: 25 August 1995     

Lumbosacral ventral spinal nerve root atrophy identified on MRI in a case of spinal muscular atrophy type II

Spinal muscular atrophies are rare genetic disorders most often caused by homozygous deletion mutations in SMN1 that lead to progressive neurodegeneration of anterior horn cells. Ventral spinal root atrophy is a consistent pathological finding in post-mortem examinations of patients who suffered from various subtypes of spinal muscular atrophy; however, corresponding radiographic findings have not been previously reported. We present a patient with hypotonia and weakness who was found to have ventral spinal root atrophy in the lumbosacral region on MRI and was subsequently diagnosed with spinal muscular atrophy. More systematic analyses of imaging studies in spinal muscular atrophy will help determine whether such findings have the potential to serve as reliable diagnostic markers for clinical evaluations or as outcome measure for clinical trials.     

Lower leg muscle involvement in Duchenne muscular dystrophy: an MR imaging and spectroscopy study

Objective  

To describe the involvement of lower leg muscles in boys with Duchenne muscular dystrophy (DMD) by using MR imaging (MRI) and spectroscopy (MRS) correlated to indices of functional status.     

MRI in the assessment of muscular pathology: a comparison between limb-girdle muscular dystrophies, hyaline body myopathies and myotonic dystrophies

Purpose

The continuous discovery of new subtypes of neuromuscular disorders demands more accurate imaging analyses. We set out to establish the specific patterns of muscular involution using magnetic resonance imaging (MRI).

Materials and methods

A systematic clinical evaluation based on the Medical Research Council scale and MRI was completed in ten patients with calpainopathy [limb-girdle muscular dystrophy (LGMD)-2A], 16 with dysferlinopathy (LGMD-2B), ten with hyaline body myopathy (HBM), six with myotonic dystrophy (MD) types 1 and 5 with MD type 2. Severity of fibroadipose degeneration was specifically staged using T1-weighted sequences. Turbo inversion recovery magnitude (TIRM) sequences were used to assess oedema-like changes.

Results

T1 scans showed recurrent patterns of fibroadipose replacement, whereas TIRM images revealed differences in oedema-like changes between the various diseases. In LGMD, the posterior compartments are more vulnerable to degeneration. In HBM, fatty muscle degeneration and oedema are allocated to muscles of the posterior compartments of the leg. In MD, fatty muscle degeneration and oedematous changes are allocated to muscles of the anterior thigh and posterior lower leg.

Conclusions

Imaging examination suggests a characteristic pattern of muscle involvement. MRI represents an important diagnostic technique useful in differential diagnosis, thanks to the distinctive patterns observed in the distribution of muscular changes between the different muscular diseases.     

MRI of the intrinsic muscles of the hand: spectrum of imaging findings and clinical correlation

OBJECTIVE: The purpose of our study was to describe the spectrum of intrinsic hand muscle abnormalities on MRI in patients with clinically evident abnormalities of the intrinsic hand muscles and to correlate clinical and radiologic findings. MATERIALS AND METHODS: MRI of 21 hands was performed in 19 patients with clinically evident or suspected intrinsic hand muscle abnormalities. All MRI was performed on a 1.5-T scanner using transaxial T1-weighted, T2-weighted, or STIR as well as contrast-enhanced T1-weighted sequences. Two observers reviewed all MR images retrospectively in a blinded fashion with regard to the exact anatomic location of the muscle abnormality, signal abnormalities, muscle atrophy, and the cause. Kappa statistics were used to calculate interobserver variability. MRI findings were compared with clinical findings using Spearman's rank test. A panel of experts assessed the impact of MRI on the diagnostic workup. RESULTS: On the basis of MRI findings, abnormalities (either MR signal abnormality or atrophy) of both the lumbrical and interosseus muscles were noted in 10 (48%) of 21 hands, of the thenar muscles in eight (38%) of 21 hands, and of the hypothenar muscles in 12 (57%) of 21 hands. The correlation between clinical and MRI findings was moderate to strong for the interosseus, thenar, and hypothenar muscles (0.43-0.84). MRI was judged to be useful for establishing the final diagnosis in 17 (81%) of 21 hands. CONCLUSION: MRI of the hands is useful and correlates well with clinical findings in patients with intrinsic hand muscle abnormalities.     

Noninvasive monitoring of gene correction in dystrophic muscle.

Gene and stem cell transfer have shown tremendous potential in rescuing dystrophic muscle in animal models. However, monitoring of gene transfer efficacy in clinical settings currently requires invasive muscle biopsies. We determined whether (1)H-magnetic resonance spectroscopy (MRS) and imaging (MRI) could be used to noninvasively monitor gene correction in dystrophic skeletal muscle. MRI/MRS measurements were performed in murine models of Limb Girdle (gammasg(-/-)) and Duchenne muscular dystrophy (mdx). Viral delivery of gammasg into gammasg(-/-) muscles was achieved using both an adenovirus and an adenoassociated virus. T(2)-weighted MRIs consistently revealed hyperintense regions in muscles of dystrophic mice, which agreed well with histologically determined damaged muscle fibers. (1)H-MRS revealed that the increase in T(2) in dystrophic muscle is not due to fatty tissue infiltration. Reintroduction of the gammasg gene in gammasg(-/-) muscles restored normal muscle histology, membrane stability, and T(2) contrast. Expression of gammasg also significantly decreased the number of pixels with increased T(2) values and MRI contrast agent uptake. Our data demonstrate that therapeutic correction of dystrophic lesions can be noninvasively monitored using endogenous MR contrast. This may be particularly relevant for future interventions in children with muscular dystrophy.     

Effect of prolonged bed rest on the anterior hip muscles

Prolonged bed rest and inactivity is known to cause muscular atrophy with previous research indicating that muscles involved in joint stabilisation are more susceptible. The anterior hip muscles are important for hip joint function and stability but little is known about the effects of prolonged inactivity on their function. This study investigated the effect of prolonged bed rest on the size of the anterior hip muscles and their pattern of recovery. The effect of resistive vibration exercise (RVE) as a countermeasure to muscle atrophy was also investigated. 12 male participants, randomly assigned to either a control or an exercise group, underwent 8 weeks of bed rest with 6 months follow-up. Changes in muscle cross-sectional area (CSA) of the iliacus, psoas, iliopsoas, sartorius and rectus femoris muscles were measured by magnetic resonance imaging at regular intervals during bed rest and recovery phases. CSAs of iliopsoas and sartorius decreased at the hip joint (p < 0.05) during bed rest but iliacus, psoas, and rectus femoris CSAs were unchanged (p > 0.05). No significant difference was found between the two groups for all muscles (all p > 0.1), suggesting inefficacy of the countermeasure in this sample. These findings suggest that prolonged bed rest can result in the atrophy of specific muscles across the hip joint which may affect its stability and function.     

Duchenne muscular dystrophy carriers

Summary By means of magnetic resonance imaging (MRI), the proton spin-lattice relaxation times (T1 values) of the skeletal muscles were measured in Duchenne muscular dystrophy (DMD) carriers and normal controls. The bound water fraction (BWF) was calculated form the T1 values obtained, according to the fast proton diffusion model. In the DMD carriers, T1 values of the gluteus maximus and quadriceps femoris muscles were significantly higher, and BWFs of these muscles were significantly lower, than in normal control. Degenerative muscular changes accompanied by interstitial edema were presumed responsible for this abnormality. No correlation was observed between the muscle T1 and serum creatine kinase values. The present study showed that MRI could be a useful method for studying the dynamic state of water in both normal and pathological skeletal muscles. Its possible utility for DMD carrier detection was discussed briefly.     

Muscle fat-fraction and mapping in Duchenne muscular dystrophy: evaluation of disease distribution and correlation with clinical assessments

Purpose

To examine the usefulness of dual-echo dual-flip angle spoiled gradient recalled (SPGR) magnetic resonance imaging (MRI) technique in quantifying muscle fat fraction (MFF) of pelvic and thighs muscles as a marker of disease severity in boys with Duchenne muscular dystrophy (DMD), by correlating MFF calculation with clinical assessments. We also tried to identify characteristic patterns of disease distribution.

Materials and methods

Twenty consecutive boys (mean age, 8.6?years?±?2.3 [standard deviation, SD]; age range, 5–15?years; median age, 9?years;) with DMD were evaluated using a dual-echo dual-flip angle SPGR MRI technique, calculating muscle fat fraction (MFF) of eight muscles in the pelvic girdle and thigh (gluteus maximus, adductor magnus, rectus femoris, vastus lateralis, vastus medialis, biceps femoris, semitendinosus, and gracilis). Color-coded parametric maps of MFF were also obtained. A neurologist who was blinded to the MRI findings performed the clinical assessments (patient age, Medical Research Council score, timed Gower score, time to run 10?m). The relationships between mean MFF and clinical assessments were investigated using Spearman’s rho coefficient. Positive and negative correlations were evaluated and considered significant if the P value was?Results The highest mean MFF was found in the gluteus maximus (mean, 46.3 %?±?24.5 SD), whereas the lowest was found in the gracilis muscle (mean, 2.7 %?±?4.7 SD). Mean MFF of the gluteus maximus was significantly higher than that of the other muscles (P?P?P?P?P?Conclusion Muscle fat fraction calculation and mapping using the dual-echo dual-flip angle SPGR MRI technique are useful markers of disease severity and permit patterns of disease distribution to be identified in patients with DMD.     

MR findings of spinal muscular atrophy Type II: sibling cases.

We present magnetic resonance (MR) findings of siblings affected by spinal muscular atrophy (SMA) Type II. MRI of their thighs showed severe muscle atrophy and fatty infiltration. Selective preservation of the adductor longus muscle, the gracilis muscle, and the sartorius muscles was observed, suggesting a characteristic finding of SMA Type II. These findings were more severe in the older patient.     

MRI findings of pancreatic lymphoma and autoimmune pancreatitis: A comparative study

Purpose

To clarify whether there are differences in MRI findings between pancreatic lymphomas and autoimmune pancreatitis (AIP).

Materials and methods

MRI of 8 patients with pancreatic lymphomas and 21 patients with AIP were retrospectively reviewed. For multifocal pancreatic lymphomas (n = 2) and AIP (n = 4), the largest 2 lesions were evaluated. Ten pancreatic lymphomas and 25 AIP were compared on three bases: the signal intensity on T2-weighted images, internal homogeneity, and presence or absence of capsule-like rim. In 8 lymphomas and 19 AIP, the enhancement pattern on dynamic MRI was compared, as well.

Results

On T2-weighted images, pancreatic lymphomas comprised 5, 5 and 4 lesions with low (iso), slightly high, and moderately high intensity, respectively, while the numbers for AIP were 14, 10, and 1 (P < 0.01). Nine of 10 (90%) lymphomas appeared homogenous, and 11 of 25 (44%) AIP were homogenous (P < 0.05). A capsule-like rim was present in 9 of 25 (36%) AIP, but was not seen in lymphomas (P < 0.05). On dynamic MRI, 18 of 19 (94.7%) AIP showed persistent (n = 5) or delayed enhancement (n = 13), and 6 of 8 (75%) lymphomas showed low intensity without delayed enhancement (P < 0.001).

Conclusion

MRI findings for pancreatic lymphomas and AIP were significantly different, which may be helpful for the differential diagnosis of these two diseases.     

下肢软组织黏液性-圆细胞型脂肪肉瘤的MR表现

目的探讨下肢软组织黏液性-圆细胞型脂肪肉瘤的MR表现及其与病理组织学的联系。方法回顾性分析6例手术病理证实为下肢软组织黏液性或黏液性-圆细胞型脂肪肉瘤患者的MR表现,观察肿瘤的位置、大小、形态、边界、内部结构及在T1W I、T2W I、T2脂肪抑制像(SPIR)和静脉注射Gd-DTPA后信号特点。结果肿块均位于下肢深部肌肉间隙内,形态多不规整,边界清楚,平均最大径约为15.2 cm,内部可见排列紊乱的纤维间隔,大部分纤维间隔厚度超过2 mm。T1W I肿块与周围骨骼肌相比呈均匀或不均匀等信号或略高、略低信号,T2W I呈高信号,脂肪抑制像肿块信号强度无减低,增强扫描见不同程度不均匀强化。结论MR可对下肢黏液性-圆细胞型脂肪肉瘤的诊断提供有价值的信息。     

MRI对先天性肌营养不良的诊断价值

目的研究先天性肌营养不良(congenital muscular dystrophies,CMD)的MRI特点。资料与方法对10例临床诊断为CMD的患儿行常规头部MRI,分析其脑白质及脑发育异常情况。脑干发育是否正常经与对照组比较后进行判断。结果10例中,1例MRI表现基本正常,其余9例均有不同程度的脑白质异常,侧脑室旁白质异常8例,皮层下白质异常9例。1例有新生儿缺氧缺血脑病(HIE)后遗改变。1例有侧脑室扩大。1例小脑发育不良。2例小脑可见多发囊性小病灶。6例脑干发育不良。结论CMD的颅脑MRI具有特征性,MRI能为CMD的诊断提供帮助。     

SURF-1基因604G→C突变所致Leigh综合征的MRI表现

目的 探讨SURF-1基因604G→C突变引起的Leigh综合征(Leigh syndrome,LS)的MRI表现.方法 对8例确诊为SURF-1基因604G→C突变的Ls患儿进行头颅MR检查,观察基底节、下丘脑、脑干及小脑灰质核团,大小脑白质异常及萎缩情况,并与典型LS患儿MRI改变进行比较.结果 3例Ls患儿MRI表现为脑干和下丘脑核受累,其中2例同时合并基底节异常;3例仅有大脑白质异常信号,无灰质核团受累;8例均存在脑萎缩,其中2例仅表现为单纯的脑萎缩,无灰质核团受累及白质异常.结论 SURF-1基因604G→C突变患儿的MRI表现具有多样化的特点.     

Oculopharyngeal muscular dystrophy: clinical and CT findings

A family affected with oculopharygeal muscular dystrophy (OPMD) is reported. This is an uncommon progressive myopathy. The proband presented for evaluation of secretory otitis media with effusion, as a result of tubal dysfunction. CT examination of the father revealed prominent muscular atrophy, and widespread fatty degeneration of the psoas, paraspinal, gluteal and femoral muscles.     

Age- and low back pain-related differences in trunk muscle activation during one-legged stance balance task

BackgroundPostural control declines with age and can be affected by low back pain. Poor balance has been reported in people with chronic low back pain (CLBP), which in turn could be explained by the changes in trunk muscle activation.Research QuestionAre there differences between younger and older adults with and without chronic low back pain (CLBP) on trunk muscle activity during one-legged stance task?MethodsTwenty (20) with, and 20 subjects without nonspecific CLBP participated in the study. Each group was comprised of 10 younger (50% males; mean age: 31 years) and 10 older adults (50% males; mean age: 71 years). Subjects performed 3 × 30-second trials of one-legged stance, with eyes open, on a force platform, while surface electromyography (EMG) measurements were obtained bilaterally on the multifidus at L5, iliocostalis lumborum at L3, rectus abdominis and biceps femoris muscles.EMG amplitude analysis was processed by the Root Mean Square (250 ms window epochs) and normalized by the peak of activation during the balance tasks, to determine the muscular activity of each muscle.ResultsParticipants with CLBP presented 15% lower lumbar muscle activation (p < 0.05), and 23% higher co-activation (ratio between rectus adominis by multifidus) than participants without CLBP, regardless of age. Significant differences (p < 0.05) between older and young groups were observed only for lower lumbar muscles (mean 24% lower in older than younger adults) and rectus adominis muscles (mean 17% lower in older than younger adults).SignificanceCLBP individuals have different trunk muscle activity than those without CLBP, and older adults exhibit lower trunk activation during one-legged stance balance task. The use of the EMG in evaluation of trunk neuromuscular function during one-legged stance may thus be a valuable tool when assessing balance in CLBP and older people.