MR and CT imaging patterns in post-varicella encephalitis

The aim of the investigation was to determine the patterns of cerebral involvement on computed tomography (CT) and magnetic resonance (MR) imaging in post-varicella encephalitis. Four children between the ages of 2 and 11 years presented over a 5-year period with a diagnosis of post-varicella encephalitis. Their imaging studies and clinical data were reviewed retro-spectively. The medical histories of all four children were noncontributory except for recent bouts of chickenpox 1 week to 3 months prior to hospitalization. Three children presented with parkinsonian manifestations. Bilateral, symmetric hypodense, nonenhancing basal ganglia lesions were found on CT. These areas showed nonenhancing low signal intensity on T1-weighted images and high signal intensity on T2-weighted images on MR. One child presented with diffuse, multiple gray and white matter lesions of similar imaging characteristics; some lesions, however, did enhance. This child had no gait disturbances. Post-varicella encephalitis can produce two patterns of dramatic CT and MR findings. With an appropriate history and clinical findings, varicella as a cause of bilateral basal ganglia or diffuse cerebral lesions can be differentiated from other possible etiologies which include trauma, anoxia, metabolic disorders and demyelinating diseases.     

急性播散性脑脊髓炎的临床及实验室研究

目的探讨急性播散性脑脊髓炎（ADEM）病因、分类与分型、临床及实验室检查的特点,提高诊断与鉴别诊断能力。方法制定较严格的诊断标准,对符合标准的34例地DEM的临床表现及实验室检查进行分析。结果34例中感染后脑脊髓炎30例,接种后脑脊髓炎4例。临床呈脑型表现16例,脑脊髓型18例。脑脊液异常12／34例,IgG指数增加16／24例。EEG异常23／31例及BAEP（5／10例）、SEP（6／8例）和VEP（3／6例）异常。脑MRI是多发性病灶31倒（91．2％）,其中较时称性的17例;34例病变部位大脑白质27例,脑干11例,小脑7例,丘脑11例,基底节6例。脊髓MRI异常4／7例。结论对有前驱感染或接种史呈脑炎我脑脊髓炎表现者,脑脊液（CSF）检查排除细菌、病毒等感染,若MRI示脑白质多发性病灶改变应考虑ADEM。     

Mucopolysaccharidoses type I and II: New neuroimaging findings in the cerebellum

BackgroundThe neuroimaging literature on mucopolysaccharidoses (MPS) is focusing mostly on supratentorial findings. Our study aims to extend the spectrum of neuroimaging findings in patients with MPS focusing on the cerebellum.MethodsTwelve patients were included (7 MPS type I and 5 MPS type II). The median age at last MRI was 9.9 years (mean age 10.1 years, range 1.8–28.8 years). All available brain MR images were retrospectively evaluated for infratentorial and supratentorial abnormalities with semiquantitative analysis and qualitative evaluation.ResultsInfratentorial findings included enlarged perivascular spaces (PVS) in the cerebellum in 7/12, mega cisterna magna in 3/12 and macrocerebellum in 2/12 patients. Enlarged cerebellar PVS developed later than those in the supratentorial brain and showed mild changes in size over time. The macrocerebellum developed progressively and seems to be caused by a thickening of the cortical cerebellar gray matter. Enlarged PVS in the brain stem were found in 10/12 patients. Supratentorial findings included enlarged PVS in all patients. Ventriculomegaly and white matter signal abnormalities were noted in 8/12, cerebral atrophy in 7/12 patients.ConclusionInvolvement of the posterior fossa structures in MPS I and II is not uncommon. Our study revealed two neuroimaging findings that have not been previously described in MPS: enlarged PVS in the cerebellum and a macrocerebellum. The pathogenesis and clinical significance of these new findings remain unclear and should be assessed in a larger cohort of patients.     

Reversible acute methotrexate leukoencephalopathy: atypical brain MR imaging features

Background: Unusual acute symptomatic and reversible early-delayed leukoencephalopathy has been reported to be induced by methotrexate (MTX). Objective: We aimed to identify the occurrence of such atypical MTX neurotoxicity in children and document its MR presentation. Materials and methods: We retrospectively reviewed the clinical findings and brain MRI obtained in 90 children treated with MTX for acute lymphoblastic leukaemia or non-B malignant non-Hodgkin lymphoma. All 90 patients had normal brain imaging before treatment. In these patients, brain imaging was performed after treatment completion and/or relapse and/or occurrence of neurological symptoms. Results: Of the 90 patients, 15 (16.7%) showed signs of MTX neurotoxicity on brain MRI, 9 (10%) were asymptomatic, and 6 (6.7%) showed signs of acute leukoencephalopathy. On the routine brain MRI performed at the end of treatment, all asymptomatic patients had classical MR findings of reversible MTX neurotoxicity, such as abnormal high-intensity areas localized in the deep periventricular white matter on T2-weighted images. In contrast, the six symptomatic patients had atypical brain MRI characterized by T2 high-intensity areas in the supratentorial cortex and subcortical white matter (n=6), cerebellar cortex and white matter (n=4), deep periventricular white matter (n=2) and thalamus (n=1). MR normalization occurred later than clinical recovery in these six patients. Conclusions: In addition to mostly asymptomatic classical MTX neurotoxicity, MTX may induce severe but reversible unusual leukoencephalopathy. It is important to recognize this clinicoradiological presentation in the differential diagnosis of acute neurological deterioration in children treated with MTX.     

苯丙酮尿症患儿治疗前后脑白质病变的观察

目的：该研究应用MRI观察晚治苯丙酮尿症(PKU)患者治疗前后脑白质病变。方法：确诊为经典型PKU患者19例,进行低苯丙氨酸(PHE)饮食治疗随诊8～16月,治疗前后分别进行了头颅MRI及智商检查。头颅MRI采用常规矢状面、轴面T1W和轴面T2W扫描,对脑白质T2高信号病变按Thompson6级分级法进行分级并评分。观察比较治疗前后脑白质病变的改变。结果：9例晚治PKU患者头颅MRI均存在脑白质病变,其病变主要表现为侧脑室周围及三角区白质等区域存在孤立性斑片状异常T2高信号,治疗前后的平均MRI脑白质T2高信号分级分别为2.59和1.76,治疗前后MRI分级按分数计算,差异有显著性(P<0.01),治疗后T2高信号等级改善。19例均存在不同程度的智力发育落后,在智商改善与T2高信号等级改善可见部分一致关系。血PHE浓度与脑白质病变间有关。结论：晚治PKU患者脑白质病变及智力发育落后具高发生率,低苯丙氨酸饮食治疗降低血苯丙氨酸浓度后脑白质病变及智商均有部分改善,提示PKU患者脑白质病变及智力损害是部分可逆的,PKU患者脑白质改变可能是导致晚治PKU患者智能发育障碍的原因之一。     

A cause of acute encephalitis: primary infection due to Epstein-Barr virus]

The neurologic complications of Epstein-Barr virus (EBV) primary infection are frequently overlooked, yet EBV is responsible for some cases of acute encephalitis. We report on a case of an infant with acute brain-stem encephalitis during EBV primary infection. OBSERVATION: A 22-month-old boy was admitted to the hospital for acute neurological symptoms. Initially, he presented ataxia and dysphagia. During the first days, his neurological status worsened with loss of consciousness requiring ventilatory support. A progressive improvement appeared after a 1 week course. One month later, a moderate ataxia was still noted, but 3 months later, the clinical examination was normal. The neuroradiological explorations revealed damage of the white matter, with high T2-weighed signal on the first brain magnetic resonance imaging. One month later, the control magnetic resonance imaging was normal. The diagnosis of EBV encephalitis was based upon the exclusion of other possible causes and positive serology for EBV, consistent with acute primary infection. CONCLUSION: EBV infection should be looked for during the etiologic work-up of an acute encephalitis. The different cases reported in the literature show a favorable initial outcome, but neurological relapse and sequelae are possible. No specific treatment is effective.     

新生鼠缺氧缺血脑损伤的组织学和MR影像变化

目的调查新生大鼠缺氧缺血脑白质和灰质损伤的组织学和磁共振（MR）影像的变化。方法7日龄Wistar鼠（n=24）随机分为假手术组和实验组（右颈动脉结扎＋吸入8％氧1．5h）。在缺氧前、缺氧最后5-10分钟、缺氧后1h和24h行头部MR扫描获得吧和表面弥散系数（ADC）。结果1．5h缺氧将结束时，在缺氧缺血半球皮质下白质和顶部灰质可见ADC明显降低和他增高；缺氧缺血后1h，皮质下白质和顶部灰质ADC部分恢复，他持续增高，而缺氧缺血后24h，T2进一步增高。与灰白质类似的MRI改变相反，组织学检查显示：缺血半球白质不可逆细胞损伤发生早于灰质。在缺氧缺血后1h，缺血半球皮质下白质可见神经纤维稀疏或紊乱，并可见TUNEL阳性细胞增加，而在缺血半球顶部灰质区未见明显细胞损伤或TUNEL阳性细胞增加，到缺氧缺血后24h，灰白质均可见明显的损伤。结论在目前的新生鼠脑缺氧缺血模型，吧和ADC均能发现急性缺氧缺血脑白质和灰质水肿或损伤，但它们不能区分白质和灰质不同的病理变化，组织学上新生鼠脑白质比灰质更易遭受缺氧缺血损害。     

Mycoplasma Pneumoniae Infection with Neurologic Complications

Background: Extrapulmonary complications of Mycoplasma pneumoniae (M. pneumoniae) infection include encephalitis, optic neuritis, acute psychosis, stroke, cranial nerve palsies, aseptic meningitis and also it may be implicated in immune mediated neurological diseases such as acute demyelinating encephalomyelitis, Guillain-Barre syndrome and transverse myelitis. Case Presentation: We present five cases with acute neurological diseases after M. pneumoniae infection. The clinical presentations were characterized by encephalitis in 2 patients, Gullain-Barre syndrome in 2 patients, transverse myelitis in 1 patient. M. pneumoniae infection was detected in serum by serological method. Only two patients had respiratory symptoms preceding M. pneumoniae infection. Brain MRI revealed hyperintensities on corpus striatum and mesencephalon in one patient with encephalitis, the other had front parietal coalescent periventricular white matter lesions on T2 images. The patient with transverse myelitis had cervical, dorsal and lumbar scattered hyperintense lesions on T2 images. Two patients were treated with high dose steroid, the other two patients received treatment with intravenous immune globuline. Conclusion: M. pneumoniae may reveal different neurologic complications with different radiologic findings.Key Words: Mycoplasma Pneumonia, Transverse Myelitis, Gullaın-Barre Syndrome, Encephalitis     

Clinical and neuroradiological findings in gliomatosis of the brain with special reference to magnetic resonance tomography

We present three cases of GC, one belonging to the brainstem, and two belonging to the hemisphere type. Two cases were investigated by MRI. Tumour infiltration, while yielding only vague CT findings, was well demonstrated in MR studies where extensive hyperintense lesions were found in T2- and proton density images. In patients studied by MR these were localized within the white matter and corpus callosum. No enhancement was seen after administration of Gd- DTPA. These findings may strongly indicate the presence of gliomatosis cerebri, when clinical and laboratory data exclude inflammatory or neurodegenerative disease. Despite the good delineation of white matter changes stereotactic biopsy remains necessary to confirm the diagnosis of gliomatosis cerebri pathohistologically.     

Symptomatic epidural lipomatosis of the spinal cord in a child: MR demonstration of spinal cord injury

We report a case of symptomatic epidural lipomatosis in an 8-year-old girl with Cushing's syndrome secondary to longstanding high-dose steroid therapy for Crohn's disease. MR imaging of the spine revealed massive diffuse epidural fat compressing the entire spinal cord with T2 prolongation in the central gray matter of the cord suggesting ischemic myelopathy. This finding has not been previously demonstrated on imaging. A proposed mechanism underlying these findings is discussed.     

磁共振成像表观扩散系数变化对新生儿化脓性脑膜炎脑损伤纵向评估

背景：既往尚无新生儿化脓性脑膜炎在不同颅脑并发症下ADC值的纵向变化研究。 目的：回顾性总结新生儿化脓性脑膜炎在发病后不同病程阶段的头颅MR表现,在髓鞘化过程中分析不同颅脑并发症下脑组织ADC值随病程的变化规律。 设计：病例对照研究。 方法：以足月新生儿化脓性脑膜炎并行头颅MR检查者为病例组,基于颅脑并发症中有无脑实质损伤灶和脑积水分为病例1组（无脑实质损伤灶和脑积水）、病例2组（有脑实质损伤灶,无脑积水）、病例3组（有脑积水无脑实质损伤灶）和病例4组（有脑实质损伤灶和脑积水）。以发病至头颅MR检查间隔时间0~7 d、~28 d、~60 d和~120 d分为病程A~D组;根据MR检查时患儿日龄,病程A组分为A1组（0~14 d）和A2组（~28 d）,病程B组分为B1组（~28 d）和B2组（~60 d）。与病例组同期因其他疾病在同院行常规头颅MR且未观察到异常病变的儿童为对照组。 主要结局指标：相同日龄或相同病程下MR评估新生儿化脓性脑膜炎脑实质ADC值变化趋势。 结果：173例新生儿化脓性脑膜炎进入本文分析,病例组MR检查302例次,病程A~D组有241例次MR检查的ADC值进入本文分析;对照组20例。随着日龄的增加,对照组和病例组ADC值均呈降低趋势。不同病程(相同日龄)比较结果中,大脑皮层、深部白质在各个病程中,病例1~3组和对照组ADC值差异均无统计学意义（胼胝体压部的部分病程除外）;皮层下白质在病程0~60 d中,病例2和3组ADC值明显低于对照组,病例3组及部分病程中病例2组ADC值明显低于病例1组,皮层下白质在病程61~120 d中,病例2、3组和对照组ADC值差异无统计学意义,病例1组(除外顶叶白质)ADC值明显高于对照组;深部灰质核团在病程0~30 d中,病例1~3组ADC值明显低于对照组,在病程31~120 d中,病例1~3组和对照组ADC值差异均无统计学意义。 结论：在新生儿化脓性脑膜炎患儿,皮层下白质在病程1~2个月ADC值降低,病程3~4个月时ADC值正常或升高,提示髓鞘化进程受阻;深部灰质核团ADC值在病程1个月内降低,而病程2~4个月时恢复正常。MR DWI定量ADC值有助于对无脑结构损伤的新生儿脑膜炎微观损伤的评估。     

表观弥散系数在2~12岁常规颅脑MRI正常的智力障碍/全面发育迟缓患儿中的应用

目的探讨快速自旋回波弥散加权成像（TSE-DWI）表观弥散系数（ADC）在2~12岁常规颅脑MRI正常的智力障碍/全面发育迟缓（ID/GDD）患儿中的应用价值。方法选择符合ID/GDD诊断标准且常规颅脑MRI正常的578例患儿及同年龄段375例正常儿童志愿者为研究对象,并收集其影像学和临床资料。所有研究对象均行颅脑TSE-DWI序列及常规序列扫描。分析正常对照组儿童各脑区不同年龄亚组、各年龄亚组不同ID/GDD程度患儿各脑区ADC值差异,社会适应行为评分（ABAS-Ⅱ）对ID/GDD患儿各脑区ADC值的影响。结果正常对照组额颞叶白质、胼胝体、内囊、半卵圆中心、小脑齿状核、视放射、丘脑、豆状核及尾状核ADC值随年龄升高而降低（P < 0.05）。各年龄组ID/GDD患儿深、浅部白质,深部灰质核团及浅部灰质4岁~组ADC值随ID/GDD程度升高而升高（P < 0.05）。深、浅部白质及深部灰质核团,各ID/GDD组ADC值随年龄的升高而降低（P < 0.05）。ID/GDD患儿ADC值随ABAS-Ⅱ评分升高而降低（P < 0.05）。结论 ADC能反映常规颅脑MRI正常ID/GDD患儿各脑区细微结构变化,对社会适应性方面也有一定的提示作用,可为ID/GDD患儿定量诊断提供客观依据。     

Methylmalonic acidemia: brain imaging findings in 52 children and a review of the literature

BACKGROUND: Methylmalonic acidemia (MMA) is an autosomal-recessive inborn error of metabolism. OBJECTIVE: To recognize the CT and MR brain sectional imaging findings in children with MMA. MATERIALS AND METHODS: Brain imaging studies (47 MR and 5 CT studies) from 52 children were reviewed and reported by a neuroradiologist. The clinical data were collected for each patient. RESULTS: The most common findings were ventricular dilation (17 studies), cortical atrophy (15), periventricular white matter abnormality (12), thinning of the corpus callosum (8), subcortical white matter abnormality (6), cerebellar atrophy (4), basal ganglionic calcification (3), and myelination delay (3). The brain images in 14 patients were normal. CONCLUSION: Radiological findings of MMA are nonspecific. A constellation of common clinical and radiological findings should raise the suspicion of MMA.     

磁敏感加权成像在早产儿伴脑室旁白质损伤中的应用研究

目的脑室旁白质损伤是早产儿围生期窒息后常见的脑损伤类型之一,其MRI表现具有特征性,但常规序列难以区分病灶内是否合并出血,而出血与否可能影响治疗和预后。该研究应用磁敏感加权成像(SWAN)来检测存在白质损伤的早产儿脑内的出血性病变。方法对临床怀疑围生期窒息后脑损伤的75例早产儿行头颅GE HDx Twin Speed 3.0T MRI检查,扫描序列包括T1FLAIR、T2FLAIR、DWI和SWAN。结果44例(58.7%)早产儿存在脑室旁白质损伤,其中4例(9.1%)存在出血性白质损伤。在这4例中有3例合并生发基质出血-脑室内出血;4例合并小脑出血;1例合并蛛网膜下隙出血。结论脑室旁白质损伤中绝大多数为非出血性损伤,当伴有生发基质出血或脑室内出血时,脑室周围白质损伤病灶中常存在出血。     

Acute disseminated encephalomyelitis

The authors report 6 children with the diagnosis of acute disseminated encephalomyelitis. Diagnosis was based on clinical and radiological findings. The most common presenting symptoms were fever and disturbed consciousness, followed by cranial nerve abnormalities and pyramidal signs. Brain MRI showed hyperintense signals on T2-weighted images, most commonly in the subcortical and periventricular white matter, brainstem, basal ganglia and thalamus. The lesions were bilateral, asymmetrical and highly variable in size and number. A preceding infection was present in 3 of 6 children. Early high-dose corticosteroids were given to all the patients. All patients recovered clinically. Follow-up ranged from 10 months to 2 years. No relapses were observed during this period. Early high-dose steroid therapy seems to be an effective treatment in acute disseminated encephalomyelitis.     

Mucopolysaccharidosis: thickening of dura mater at the craniocervical junction and other CT/MRI findings

Cranial CT and/or MRI imaging of 8 patients with mucopolysaccharidosis (MPS) was retrospectively evaluated. Two patients had MPS IH, 1 had MPS IS, 1 had MPS IVA and 4 had MPS IV. CT and MRI showed thickening of dura mater at the cranio-cervical junction, causing narrowing of the subarachnoid space, in all the patients examined. Spinal cord compression was detected in 4 patients. Other findings were: white matter alterations, mild to severe hydrocephalus, skull dysplasia and odontoid dysplasia. White matter alterations were evident as large areas and as multiple dispersed spots of prolonged T1 and T2 value. Reduced gray/white matter contrast was demonstrated on T2-weighted MRI images. It is important to examine the cranio-cervical junction carefully for thickening of dura mater in all patients with mucopolysaccharidosis examined by CT or MRI, because of the generally progressive clinical course of MPS. In patients with symptomatic cord compression, surgical intervention should be considered.     

新生儿低血糖脑损伤早期MRI表现及其演变

目的 通过对低血糖患儿进行低血糖后早期、动态的MRI检查,结合临床特征探讨不同程度低血糖脑损伤患儿的MRI改变。方法 选取我院2005年5月至2013年7月以低血糖收入院,在低血糖后1周内完善首次常规MRI及弥散加权成像（diffusion-weighted imaging,DWI）检查确诊为新生儿低血糖脑损伤的患儿49例。其中34例在低血糖发生后2～3周完善第2次MRI检查,7例完善第3次MRI检查。结果 49例患儿首次MRI均有顶、枕部受累;顶、枕部受累为主33例,顶、枕部合并额叶、颞叶受累6例,弥漫性皮层及皮层下白质受累10例。均表现为受累部位DWI高信号,T1和T2加权像信号改变不明显。部分患儿合并深部脑白质及灰质受累表现。34例患儿第2次MRI检查,有20例表现为损伤部位DWI低信号,T1加权像低信号,T2加权像高信号,3例较前略吸收,11例未见异常信号。7例患儿完善第3次复查,分别出现脑软化,髓鞘发育落后,白质容积减小,胼胝体发育不良。对比不同程度脑损伤患儿的临床症状,发现临床症状较重者脑损伤也较重。结论 低血糖脑损伤具有顶、枕部易损性。低血糖后1周内完善DWI检查对急性期低血糖脑损伤有提示作用。MRI动态观察发现轻症损伤可恢复。损伤较重的患儿可出现坏死及脑软化。部分合并深部白质、灰质损伤的病例,不能除外缺氧缺血所致。     

Associated brain abnormalities in patients with corpus callosum anomalies

Forty-nine patients with corpus callosum (CC) anomalies were evaluated in terms of the clinical features and magnetic resonance imaging (MRI) findings. CC anomalies were classified as CC agenesis: 6 (12%), CC hypogenesis: 5 (10%), and CC hypoplasia: 38 (78%). In the CC hypoplasia group the mean value of the genu thickness of the CC was 0.29 +/- 0.1 cm, which was less than the normal value of the age-matched normal children (normal range: 0.6-1.2 cm). The associated brain abnormalities were in five distinct groups: gray matter abnormalities, white matter abnormalities, midline brain structure defects, cortical atrophy, and encephalomalacia. There was no uniformity for the clinical spectrum of CC anomalies. Microcephaly, developmental delay and seizures were the prominent findings in patients. The clinical features were more severe in cases with associated brain anomalies.     

Brain abnormalities in extremely low gestational age infants: a Swedish population based MRI study

AIMS: Brain abnormalities are common in preterm infants and can be reliably detected by magnetic resonance (MR) imaging at term equivalent age. The aim of the present study was to acquire population based data on brain abnormalities in extremely low gestational age (ELGA) infants from the Stockholm region and to correlate the MR findings to perinatal data, in order to identify risk factors. METHODS: All infants with gestational age <27 weeks, born in the Stockholm region between January 2004 and August 2005, were scanned on a 1.5 T MR system at term equivalent age. Images were analysed using a previously established scoring system for grey and white matter abnormalities. RESULTS: No or only mild white matter abnormalities were observed in 82% and moderate to severe white matter abnormalities in 18% of infants. The Clinical Risk Index for Babies (CRIB II) score, use of inotropes, the presence of high-grade intraventricular haemorrhages and posthaemorrhagic ventricular dilatation were associated with white matter abnormalities. CONCLUSION: The incidence of moderate to severe white matter abnormalities in a population-based cohort of ELGA infants from the Stockholm region was 18%. To examine the clinical relevance of these promising results, neurodevelopmental follow up at 30 month corrected age, is ongoing.     

White matter abnormalities in patients with treated hyperphenylalaninaemia: Magnetic resonance relaxometry and proton spectroscopy findings

In order to further clarify the pathogenesis and clinical significance of MRI white matter abnormalities in treated hyperphenylalaninaemia (HPA), ten patients (seven type I HPA, two type II and one type III) underwent T₂ relaxometry (n=8) and/or¹H spectroscopy (n=7) in addition to conventional MR spin-echo imaging at 1.5 T. Two patients with severe MRI abnormalities had repeat examinations during and after a 6-to 8-month period of strict diet control. The clinical evaluation included a detailed neurological examination. In nine out of ten patients visual evoked potentials (VEP) were obtained parallel to the MR examination. MR imaging demonstrated typical symmetrical areas of prolonged T₂ relaxation time predominantly in the posterior periventricular white matter in all but one of type I and II patients. There was no consistent relationship between MRI findings and time of diagnosis/initiation of therapy, IQ or visual evoked potential changes. MRI abnormalities tended to be more severe in patients with poor dietary control and high current plasma phenylalanine levels, whereas a normal MRI was found only in patients with plasma phenylalanine levels continuously below 0.36 mmol/l. There was marked regression of MRI abnormalities already after 3 months of strict diet control. T₂ relaxometry showed a bi-exponential behaviour of T₂ in the affected white matter, with a slow component of about 200–450 ms, indicating an increase in free (extracellular) water.¹H spectroscopy revealed no signs of severe neuronal damage. We conclude, that the observed white matter changes in treated HPA probably represent reversible structural myelin changes rather than permanent demyelination.