MR imaging findings in children with merosin-deficient congenital muscular dystrophy

BACKGROUND AND PURPOSE: Our purpose was to determine the brain MR imaging characteristics of merosin-deficient congenital muscular dystrophy in children. METHODS: We reviewed the MR imaging findings of the brain in three children with known merosin-deficient congenital muscular dystrophy to determine the presence of any cerebral or cerebellar abnormalities of development or abnormalities of the white matter. RESULTS: In all three patients, there was normal formation of the cerebrum, the cerebellum, and no evidence of neuronal migration anomalies. All three patients had abnormal white matter in the cerebrum, with sparing of the corpus callosum, internal capsule, cerebellum, and brain stem. CONCLUSION: MR imaging of the brain in children with merosin-deficient congenital muscular dystrophy reveals a consistent pattern of white matter abnormality. We postulate that disruption of the blood-brain barrier associated with merosin deficiency leads to increased water content, resulting in abnormal white matter signal intensity.     

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。     

Cerebellar MR in Fukuyama congenital muscular dystrophy: polymicrogyria with cystic lesions.

PURPOSETo determine the MR appearance of cerebellar abnormalities in Fukuyama congenital muscular dystrophy.METHODSWe reviewed brain MR images of 25 patients with Fukuyama congenital muscular dystrophy and examined the autopsy specimens of a 23-month-old girl with the disease to determine the pathologic nature of the MR findings.RESULTSMR studies revealed two characteristic cerebellar abnormalities: (a) disorganized cerebellar folia (16 cases) that were recognized as unusual distortions of the cortex; and (b) clusters of intraparenchymal cysts (23 cases). The two lesions were located close to each other, and milder lesions tended to affect only the superior semilunar lobule. The autopsy specimen revealed small cerebellar cysts, which consisted of dilated subarachnoid spaces buried beneath the malformed cortex.CONCLUSIONThe disorganized folia represent cerebellar polymicrogyria, and the presence of cerebellar cysts is related to the polymicrogyria. These two MR changes are often present in Fukuyama congenital muscular dystrophy and are distinct enough to suggest the radiologic diagnosis.     

Walker–Warburg syndrome variant

A Turkish patient with cobblestone lissencephaly and eye involvement without characteristic muscular changes for congenital muscular dystrophy died at the age of 3 months presented with neonatal apneic periods and generalized seizures. Serum creatine kinase level, electromyography, chromosome analysis and blood biochemistry were normal. Unilateral microphthalmia, retinal dysplasia and internal strabismus were the ocular findings. Magnetic resonance imaging clearly demonstrated the thickened, irregular, nearly agyric cobblestone cerebral cortex with underlying unmyelinated white matter, hydrocephalus, hypoplastic corpus callosum, brain stem and cerebellum with retrocerebellar cyst and posterior cephalocele.     

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。     

Walker-Warburg syndrome.

The Walker-Warburg syndrome (WWS) is a rare autosomal recessive disorder characterized by lissencephaly, cerebellar and retinal malformations, and congenital muscular dystrophy. We report a new case of WWS identified with the aid of cranial MR and briefly review the radiologic findings of this lethal syndrome.     

Serial MRI in Fukuyama type congenital muscular dystrophy

Summary Serial MRI of the brain of a female infant with Fukuyama type congenital muscular dystrophy (FCMD) is presented. Initial MRI revealed diffuse abnormal signal in the cerebral white matter extending peripherally. On follow-up studies, the abnormal signals disappeared or decreased from the posterior to anterior, and from central to peripheral. These changes in signal intensity correlate well with the process of myelination as demonstrated in histochemical studies. It appears that the abnormal signals in FCMD are caused by delayed myelination. When abnormal signal intensity is seen in the cerebral white matter of a developmentally delayed infant, serial MRI may be used to follow the course of the illness.     

Tall vertebrae at birth: a radiographic finding in flaccid infants

It has been well documented that children with severe neuromuscular disorders have tall vertebrae, presumably a consequence of altered mechanical forces. This finding was present in four neonates who were born with severe "floppy" hypotonia due to Werdnig-Hoffmann disease (two cases), nonspecific neonatal myopathy, and congenital muscular dystrophy. Fetal vertebral development is normally modified by intrauterine muscle tension and fetal activity.     

MR evaluation of the hippocampus in patients with congenital malformations of the brain

BACKGROUND AND PURPOSE: Developmental changes in hippocampal formations (HFs) have been reported in association with agenesis of the corpus callosum, lissencephaly, and holoprosencephaly. The purpose of this study was to evaluate the developmental changes in HFs in patients with a variety of other congenital brain malformations. METHODS: MR images of 44 patients with congenital brain malformations associated with 11 different brain disorders were reviewed retrospectively. Five patients had more than two anomalies. Imaging and clinical findings were evaluated for the shape, size, degree of inversion, and side of abnormal HF. RESULTS: Vertically oriented or globular-shaped HFs were observed in 28 patients (64%) on coronal MR images. All patients with agenesis of the corpus callosum (n = 7), lissencephaly (n = 1), holoprosencephaly (n = 3), and Fukuyama muscular dystrophy (n = 3) had an abnormal HF. A high prevalence of abnormalities was observed in patients with polymicrogyria (11/12, 92%), heterotopia (4/5, 80%), tuberous sclerosis (2/3, 67%), and schizencephaly (2/4, 50%). Patients whose abnormalities were symmetrical had bilateral abnormal HFs, whereas those with polymicrogyria, schizencephaly, and heterotopia, whose abnormalities were localized, tended to have unilateral abnormal HFs. CONCLUSION: Hippocampal developmental abnormalities are found in a high percentage of patients with congenital malformations. Focusing on the morphologic abnormalities of the HF on coronal MR images may help in the detection of diseases associated with brain anomalies, especially subtle cortical disorders.     

MR imaging of myopathy

Magnetic resonance imaging was performed in 8 patients with muscle disease and 6 normal controls. High intensity areas of varying dimensions were found in thigh muscles of the patients with progressive muscular dystrophy (PMD) and congenital myopathy. Shortened T1 and prolonged T2 values with disease progression were characteristic. The T1 values were variable and prolonged, T2 values were more characteristic of progressive muscular degeneration. The T1 value may help to detect the early stage of PMD. Magnetic resonance imaging is useful in detecting the muscle lesions in PMD and essential for selection of a biopsy site.     

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.     

Nuclear magnetic resonance (NMR) imaging in white matter disease of the brain using spin-echo sequences

Attention is drawn to the use of nuclear magnetic resonance (NMR) spin-echo sequences in the recognition of white matter disease of the brain. In 5 patients with multiple sclerosis, 8 lesions were seen with postcontrast x-ray computed tomography (CT) (37.5 g of iodine), 33 with inversion-recovery (IR) scans, and 47 with spin-echo (SE) scans. Partial volume effects were less of a diagnostic difficulty with SE scans than with IR scans. Extensive areas of abnormal white matter were seen with CT, IR, and SE scans in a patient with leucodystrophy associated with congenital muscular dystrophy. In a patient with adrenoleucodystrophy focal lesions were seen with CT, IR, and SE scans. In addition, loss of gray-white matter contrast was seen in both occipital lobes with IR scans. Extensive areas of white matter involvement were also seen in a case of Binswangers disease.     

Gastrointestinal manifestations of the muscular dystrophies.

Five patients with acute megacolon with varied types of progressive muscular dystrophy are presented. Dysfunction of smooth muscle among patients with muscular dystrophy is reviewed. The extra gastrointestinal roentgen features are summarized. Recognition of the diffuse smooth muscular involvement among patients with muscular dystrophy is stressed for proper diagnosis and patient management.     

Difficulties with prenatal diagnosis of the Walker-Warburg syndrome

We describe a postnatally diagnosed case of Walker-Warburg syndrome - a form of congenital muscular dystrophy with lissencephaly and eye abnormalities. We reviewed the literature to highlight its clinico-radiological diagnostic features and discuss the difficulties encountered with prenatal diagnosis, especially in cases with no positive family history. An increased awareness of this rare but lethal condition, and a high index of suspicion during routine antenatal ultrasound, could prompt further advanced fetal ultrasonography and magnetic resonance imaging, and aid in timely prenatal diagnosis, management, and counseling.     

Myocardial T1-mapping and Extracellular Volume Quantification in Patients and Putative Carriers of Muscular Dystrophy: Early Experience

To assess myocardial fibrosis associated with muscular dystrophy, T₁-mapping and extracellular volume fraction (ECV) quantification was prospectively performed using cardiovascular MR (CMR) imaging in 6 male patients with muscular dystrophy and 5 female putative carriers of Duchenne or Becker muscular dystrophy. Five patients and all putative carriers had an elevated ECV (>29.5% for men and >35.2% for women), suggesting that ECV has a potential to detect diffuse fibrotic changes in patients and putative carriers of muscular dystrophy.     

Invited. Fukuyama congenital muscular dystrophy: A neuroradiologic review

We reviewed neuroradiologic findings of Fukuyama congenital muscular dystrophy (FCMD) and correlated them with the known neuropathology. All patients showed thick and bumpy cortices with shallow sulci corresponding to polymicrogyria, and approximately half of the patients showed pachygyric cortex with smooth surface corresponding to type II lissencephaly. The two types of cortical dysplasias presented characteristic distributions: the former demonstrated frontal lobe involvement in all and parietotemporal lobe involvement in some, whereas the latter involved the temporo-occipital lobes. Most patients showed prolonged T1 and T2 signal in the white matter, which was indistinct in neonates and infrequently seen in adolescents. Cerebellar polymicrogyria depicted as disorganized cerebellar foliation accompanying cysts were found more than 90% of the patients. In conclusion, brain MRI demonstrates findings consistent with the known neuropathology of FCMD. The detection of the two types of cerebral cortical dysplasia with characteristic distribution and cerebellar abnormalities is helpful in the differential and early diagnosis.     

Disorders of cortical formation: MR imaging features

The purpose of this article was to review the embryologic stages of the cerebral cortex, illustrate the classification of disorders of cortical formation, and finally describe the main MR imaging features of these disorders. Disorders of cortical formation are classified according to the embryologic stage of the cerebral cortex at which the abnormality occurred. MR imaging shows diminished cortical thickness and sulcation in microcephaly, enlarged dysplastic cortex in hemimegalencephaly, and ipsilateral focal cortical thickening with radial hyperintense bands in focal cortical dysplasia. MR imaging detects smooth brain in classic lissencephaly, the nodular cortex with cobblestone cortex with congenital muscular dystrophy, and the ectopic position of the gray matter with heterotopias. MR imaging can detect polymicrogyria and related syndromes as well as the types of schizencephaly. We concluded that MR imaging is essential to demonstrate the morphology, distribution, and extent of different disorders of cortical formation as well as the associated anomalies and related syndromes.     

Contrast agent-enhanced magnetic resonance imaging of skeletal muscle damage in animal models of muscular dystrophy.

Membrane lesions play an early role in the pathogenesis of muscular dystrophy. Using a new albumin-targeted contrast agent (MS-325), sarcolemmal integrity of two animal models for muscular dystrophy was studied by MRI. Intravenously injected MS-325 does not enter skeletal muscle of normal mice. However, mdx and Sgca-null mutant mice, animal models for Duchenne and sarcoglycan-deficient limb-girdle muscular dystrophy, respectively, showed significant accumulation of MS-325 in skeletal muscle. The results suggest that contrast agent-enhanced MRI could serve as a common, noninvasive imaging procedure for evaluating the localization, extent, and mechanisms of skeletal muscle damage in muscular dystrophy. Furthermore, this method is expected to facilitate assessment of therapeutic approaches in these diseases.     

Brain MR in Fukuyama congenital muscular dystrophy.

PURPOSETo determine the MR characteristics of brain abnormalities in Fukuyama congenital muscular dystrophy (FCMD).METHODSWe reviewed 30 MR examinations of 21 patients with FCMD to assess cerebral and cerebellar cortical dysplasia, white matter changes, and miscellaneous abnormalities.RESULTSOn MR images, all patients had thick and bumpy cortices with shallow sulci corresponding to polymicrogyria, and 12 patients had pachygyric cortices with smooth surfaces, corresponding to type II lissencephaly. Both types of cortical dysplasia had characteristic distributions: the first type involved the frontal lobe in all 21 patients and also the parietotemporal lobe in 6 patients; the second type involved the temporooccipital lobes. Eighteen patients had prolonged T1 and T2 signal in the white matter, which was indistinct in neonates and seen infrequently in adolescents. In four patients, abnormal vessels were seen within the pachygyric cortices.CONCLUSIONMR studies of the brain show findings consistent with the known characteristics of FCMD. The MR detection of the two types of cerebral cortical dysplasia with characteristic distribution and cerebellar abnormalities is helpful in the differential and early diagnosis of FCMD.