儿童神经元蜡样质脂褐素增多病的MRI诊断

目的 分析不同类型神经元蜡样质脂褐素增多病(NCL)的MRI特征和诊断价值。方法 搜集6例经病理证实的NCL病例，其中2例为婴儿型(INCL)，2例为晚期婴儿型(LINCL)，2例为青少年型(JNCL)；6例正常儿童作对照组。所有病例均做MR检查。结果 (1)脑萎缩：2例INCL均表现为明显大脑萎缩，2例LINCL和2例JNCL均表现为明显小脑萎缩；2例JNCL同时表现为轻度大脑萎缩。(2)脑白质T2WI上信号改变：6例病人中2例INCL和2例LINCL的半卵圆中心有稍高信号；2例INCL、2例LINCL和1例JNCL的侧脑室前角有稍高信号。(3)灰质核团T2WI上信号改变：除1例JNCL外，余5例患儿的丘脑呈低信号，2例LINCL双侧壳核和苍白球呈明显低信号。对照组6例均无异常。结论 MRI能敏感地发现NCL的早期改变，并对NCL的诊断和分型提供帮助。     

MR imaging and localized proton MR spectroscopy in late infantile neuronal ceroid lipofuscinosis.

PURPOSELate juvenile neuronal ceroid lipofuscinosis (NCL) is a lysosomal neurodegenerative disorder caused by the accumulation of lipopigment in neurons. Our purpose was to characterize the MR imaging and spectroscopic findings in three children with late infantile NCL.METHODSThree children with late infantile NCL and three age-matched control subjects were examined by MR imaging and by localized MR spectroscopy using echo times of 135 and 5. Normalized peak integral values were calculated for N-acetylaspartate (NAA), choline, creatine, myo-inositol, and glutamate/glutamine.RESULTSMR imaging revealed volume loss of the CNS, most prominently in the cerebellum. The T2-weighted images showed a hypointense thalamus and hyperintense periventricular white matter. Proton MR spectra revealed progressive changes, with a reduction of NAA and an increase of myo-inositol and glutamate/glutamine. In long-standing late infantile NCL, myo-inositol became the most prominent resonance. Lactate was not detectable.CONCLUSIONMR imaging in combination with proton MR spectroscopy can facilitate the diagnosis of late infantile NCL and help to differentiate NCL from other neurometabolic disorders, such as mitochondrial or peroxisomal encephalopathies.     

儿童神经元蜡样质脂褐素沉积病的MRI及MRS表现

目的：分析婴儿型和晚期婴儿型神经元蜡样质脂褐素沉积病（NCL）的MRI、磁共振波谱（^1H—MRS）表现。方法：对2例婴儿型和8例晚期婴儿型NCL患儿行磁共振平扫和磁共振波谱检查。总结分析各种特征性影像表现及N-乙酰天门冬氨酸（NAA）、总肌酸（Cr）、胆碱复合物（Cho）、NAA／Or、Cho／Cr比值的变化规律。结果：10例患儿都表现为逐渐进展的脑萎缩,婴儿型以大脑萎缩为早期表现,晚期婴儿型以小脑萎缩为早期表现。2例婴儿型病例及病史4～5年的晚期婴儿型患儿可见大脑半球白质的异常高信号,脑室旁白质最为明显。婴儿型病例见双侧丘脑和基底节核团T2WI低信号。8例发现颅骨板障明显增厚。磁共振波谱显示随着病程延长,晚期婴儿型病例的NAA／Cr比值逐渐降低,Cho／Cr值未见明显变化。婴儿型病例末观测到NAA峰,Cho／Cr水平降低,肌醇（mi）水平明显增高。结论：MRI和^1H—MRS可以敏感地发现婴儿型和晚期婴儿型患儿脑内的异常改变9有助于NCL的诊断和分型,并可以评价疾病的严重程度,监测病情变化。     

Magnetic resonance imaging in neuronal ceroid lipofuscinosis

Neuronal ceroid lipofuscinosis is a group of neurodegenerative disorders characterized by accumulation of lipofuscin and/or ceroid within the tissues of the body. These entities are manifest by visual, intellectual, and motor deterioration as well as recurrent seizures. Computed tomography has been shown to demonstrate changes of cerebral atrophy in more severely affected patients. Seven patients with neuronal ceroid lipofuscinosis were examined with both computed tomography and magnetic resonance imaging, and the results were correlated with the clinical severity of the disorder. Two less severely affected patients had normal results on computed tomography and magnetic resonance imaging studies. Varying degrees of cerebral atrophy were seen in the remaining five patients with both computed tomography and magnetic resonance imaging. Severity of atrophy correlated with the severity of disability in these patients. Abnormal white matter was seen in the two most severely affected patients only with magnetic resonance imaging. Although the findings in patients with neuronal ceroid lipofuscinosis were nonspecific, the increased sensitivity of magnetic resonance imaging for subtle white matter abnormalities over computed tomography may prove helpful in monitoring the progression of this rare disorder.     

Deceptively normal MR in early infantile Krabbe disease.

The authors present two cases of 5-month-old children with early infantile Krabbe disease studied by CT and MR. Both infants had characteristic CT scans for the disease consisting of symmetric hyperdensity involving the cerebellum, thalami, caudate, corona radiata, and brain stem. One of the infants had a deceptively normal initial MR examination, with dramatic progression of the white-matter disease over the following 4 months.     

Neuroradiologic findings in children with mitochondrial disorders.

PURPOSEWe report the neuroradiologic findings in 25 children with various mitochondrial diseases.METHODSTwenty-two children with a mitochondrial disorder had MR imaging of the brain and three children had CT studies. In all cases, the diagnosis was based on examination of muscle morphology, analysis of oxygen consumption and respiratory chain enzyme activity in isolated muscle mitochondria, and analysis of rearrangements of the mitochondrial DNA.RESULTSFifteen patients were found to have the classical syndromes of mitochondrial diseases. Four children had Kearns-Sayre syndrome, but only one had the typical neuroradiologic findings of basal ganglia and brain stem lesions, T2 hyperintensity of the cerebral white matter, and cerebellar atrophy; the others had nonspecific or normal findings. Eight patients had Leigh syndrome, and all showed changes in the putamina. Involvement of the caudate nuclei, globus pallidi, thalami, and brain stem was common, and diffuse supratentorial white matter T2 hyperintensity was seen in two of these patients. Three patients had mitochondrial encephalopathy with lactic acidosis and strokelike episodes (MELAS), with infarctlike lesions that did not correspond to the vascular territories. Ten children with complex I or IV deficiencies and abnormal muscle morphology had nonspecific imaging findings, such as atrophy and abnormal or delayed myelination. One patient with combined complex I and IV deficiency had extensive white matter changes. None of the patients with clinical encephalopathy had normal findings.CONCLUSIONMR imaging is helpful in the diagnosis of the classical mitochondrial diseases; however, nonspecific findings are common.     

Acute encephalopathy with bilateral thalamotegmental involvement in infants and children: imaging and pathology findings.

PURPOSETo investigate the imaging and pathologic characteristics of acute encephalopathy with bilateral thalamotegmental involvement in infants and children.METHODSFive Japanese children ranging in age from 11 to 29 months were studied. We performed CT imaging in all patients, 10 MR examinations in four patients, and an autopsy in one patient.RESULTSThe encephalopathy affected the thalami, brain stem tegmenta, and cerebral and cerebellar white matter. The brain of the autopsied case showed fresh necrosis and brain edema without inflammatory cell infiltration. Petechiae and congestion were demonstrated mainly in the thalamus. CT and MR images showed symmetric focal lesions in the same areas in the early phase. These lesions became more demarcated and smaller in the intermediate phase. The ventricles and cortical sulci enlarged. MR images demonstrated T1 shortening in the thalami. The prognosis was generally poor; one patient died, three patients were left with severe sequelae, and only one patient improved.CONCLUSIONSThe encephalopathy might be a postviral or postinfectious brain disorder. T1 shortening in the thalami indicated the presence of petechiae.     

Decreased T2 signal in the thalami may be a sign of lysosomal storage disease

INTRODUCTION: Lysosomal disorders are rare and are caused by genetically transmitted lysosomal enzyme deficiencies. A decreased T2 signal in the thalamus has occasionally been reported. AIMS: Because the finding of bilateral abnormal signal intensity of the thalamus on T2-weighted images has not been systematically reviewed, and its value as a diagnostic tool critically evaluated, we carried out a systematic review of the literature. METHODS: Articles in English with 30 trios of keywords were collected from PubMed. Exclusion criteria were lack of conventional T2-weighted images in the protocol and not being a human study. Finally, 111 articles were included. The thalamus was considered affected only if mentioned in the text or in the figure legends. RESULTS: Some 117 patients with various lysosomal diseases and five patients with ceruloplasmin deficiency were reported to have a bilateral decrease in T2 signal intensity. At least one article reported a bilateral decrease in signal intensity of the thalami on T2-weighted images in association with GM1 and GM2 gangliosidosis and with Krabbe's disease, aspartylglucosaminuria, mannosidosis, fucosidosis, and mucolipidosis IV. Furthermore, thalamic alteration was a consistent finding in several types of neuronal ceroid lipofuscinosis (NCL) including CLN1 (infantile NCL), CLN2 (classic late infantile NCL), CLN3 (juvenile NCL), CLN5 (Finnish variant late infantile NCL), and CLN7 (Turkish variant late infantile NCL). CONCLUSION: A decrease in T2 signal intensity in the thalami seems to be a sign of lysosomal disease.     

Bithalamic hyperintensity on T2-weighted MR: vascular causes and evaluation with MR angiography.

PURPOSETo determine whether MR angiography can be used to differentiate between the two vascular causes of bithalamic hyperintensity on T2-weighted MR images: "top of the basilar" artery occlusion and deep cerebral vein thrombosis.METHODSA retrospective review identified six patients with bithalamic T2 hyperintensity of vascular causes. MR angiography was performed in four patients, MR angiography and conventional angiography in one patient, and conventional angiography in one patient. Data pertaining to clinical presentation and hospital course were collected. MR angiographic techniques were multislab overlapping three-dimensional time-of-flight, 2-D time-of-flight, and 2-D phase-contrast.RESULTSThree cases of top of the basilar artery occlusion and three cases of deep cerebral vein thrombosis were recognized. In all cases, T2 hyperintensity in a vascular distribution suggested cerebral occlusive disease. Infarction involving the thalami and basal ganglia was present in two cases of deep cerebral vein thrombosis. Infarction of the thalami, mesodiencephalic region, and cerebellar hemispheres was present in two cases of basilar artery occlusion. Bithalamic infarction alone was seen in one case of deep cerebral vein thrombosis and one case of basilar artery occlusion. In the five cases in which MR angiography was used, this technique accurately distinguished the vessels involved (arterial or venous).CONCLUSIONMR angiography is a useful adjunct to MR imaging in the evaluation of bithalamic T2 hyperintensity. It does help distinguish between the two vascular causes: top of basilar artery occlusion and deep cerebral vein thrombosis.     

Infantile-onset spinocerebellar ataxia: MR and CT findings.

PURPOSETo report the MR and CT findings in a hereditary disease, infantile-onset spinocerebellar ataxia (IOSCA).METHODSWe studied the brains of 17 patients with infantile-onset spinocerebellar ataxia with CT and/or MR to determine the presence of cerebellar and brain stem atrophy and parenchymal lesions.RESULTSCerebellar cortical atrophy was seen in 13 patients. The degree of atrophy correlated with increasing age and clinical deterioration. Brain stem atrophy was seen in 8 patients. It was never severe, and the basis pontis was not flattened even in the most severe cases. Hyperintense lesions were noted within the white matter of cerebellum, in the dentate nuclei, and in the middle cerebellar peduncles in 3 patients. The upper cervical cord was seen in 9 patients and showed mild to moderate atrophy in 4. The basal ganglia and cerebral hemispheres were normal, except in 2 patients transient cortical and subcortical lesions developed during episodes of status epilepticus; mild cortical brain atrophy subsequently developed.CONCLUSIONThe brain MR and CT findings of patients with infantile-onset spinocerebellar ataxia correspond to the neuropathologic entities of cerebellar cortical atrophy, olivopontocerebellar atrophy, and spinocerebellar atrophy. The appearance of the findings followed a uniform time sequence from cerebellar cortical atrophy in the early stage of the disease to olivopontocerebellar atrophy and spinocerebellar atrophy in the later stage. The severity of atrophy correlated with clinical deterioration.     

Deep gray matter involvement in children with acute disseminated encephalomyelitis.

PURPOSETo review the frequency, distribution, and extent of deep gray matter disease in children with acute disseminated encephalomyelitis.METHODSThe MR examinations of 10 patients, who were discharged with the clinical diagnosis of acute disseminated encephalomyelitis between 1986 and 1992, were retrospectively reviewed. Locations of abnormal signal in the cerebral and cerebellar cortices, white matter, and deep gray matter nuclei were recorded. Precontrast and postcontrast images were compared, when available, to assess degree of enhancement (if any).RESULTSSix patients had foci of prolonged T2 relaxation in the deep gray matter, ranging in size from less than 1 cm to 4 cm. The caudate heads were involved in 4 patients, caudate body in 3, globus pallidus in 3, putamina in 3, and thalami in 4. In 1 patient, the thalami were involved nearly symmetrically, with mild mass effect. Asymmetric subcortical white matter involvement was present as well. Prolonged T2 relaxation was present within the cerebral cortex in 4 patients and was associated with subcortical white matter abnormality in 3 and more central white matter disease in 1. Nine of 10 patients demonstrated foci of T2 prolongation in white matter, most commonly involving the subcortical region, corona radiata, and centrum semiovale. Three patients also had periventricular foci. Of the 3 patients receiving gadolinium, one showed no enhancement. Two of the patients showed enhancement of some but not all lesions. One patient, who had normal brain MR findings and symptoms of myelopathy, underwent spine MR which demonstrated focal linear areas of T2 prolongation in the spinal cord at levels C-1 to C-2 and T-6.CONCLUSIONInvolvement of deep gray matter was common in our small series. The finding of T2 prolongation in these structures does not preclude the diagnosis of acute disseminated encephalomyelitis in the proper clinical setting. Because thalamic involvement is reported to be rare in multiple sclerosis, it may prove useful in distinguishing between acute disseminated encephalomyelitis and the initial presentation of multiple sclerosis.     

Early infantile form of Krabbe disease with optic hypertrophy: serial MR examinations and autopsy correlation.

The development of white matter lesions in a case of autopsy-proved early infantile form of Krabbe disease was monitored by serial MR examinations. Hypertrophy of the optic nerves was present late in the course of the patient''s disease and is a remarkable feature in this case.     

Computed tomography in neuronal ceroid lipofuscinosis

Summary The computed tomography (CT) findings in a verified case of neuronal ceroid lipofuscinosis (NCL) are presented. CT revealed diffuse and severe cerebral atrophy, reflected by generalized subarachnoid space enlargement and symmetric ventricular dilation. There was no evidence of abnormalities of the white matter. The CT features in our case of NCL correspond perfectly with the neuropathologic changes of the disease mentioned in the literature. Furthermore, CT is of considerable help in differentiating between those inherited metabolic brain diseases characterized primarily by white matter involvement and those presenting predominantly with changes of grey matter.     

Venous congestion: an MR finding in dural arteriovenous malformations with cortical venous drainage.

PURPOSETo present the MR findings of intracranial dural arteriovenous malformations with cortical venous drainage, emphasizing the parenchymal changes.METHODSConventional MR and x-ray angiograms in 13 patients with dural arteriovenous malformations and cortical venous reflux were reviewed. The site of the shunt, location of the venous reflux, and presence of venous stenosis were assessed on the angiograms. Parenchymal changes, dilated vessels, and venous occlusive disease were assessed on MR.RESULTSOn MR, 10 of the 13 patients (77%) had dilated pial vessels. Two patients had hydrocephalus. Two patients presented with parenchymal bleeds, one with a subdural component, both remote from the nidus. Two patients presented with subarachnoid hemorrhage. One patient had a parenchymal bleed 9 months after presentation. Venous occlusion was evident on MR in 2 patients. Diffuse white matter edema in the cerebellar or cerebral hemispheres was present on MR in 4 patients and correlated with neurologic deficits. In 2 of these 4 patients, gadolinium enhancement was seen in the periphery of the involved hemisphere.CONCLUSIONSOn MR a surplus of pial vessels suggests a dural arteriovenous malformation with cortical venous drainage. The MR finding of white matter edema deep in the cerebral or cerebellar hemispheres is direct evidence of a venous congestion.     

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.     

MR of the brain in mitochondrial myopathy.

PURPOSETo determine the spectrum of MR findings in patients with mitochondrial myopathy and correlate them with central nervous system symptoms and signs.METHODSWe performed a prospective evaluation of the MR findings of eight patients with mitochondrial myopathy (three with Kearns-Sayre syndrome and five with chronic progressive external ophthalmoplegia), six of whom had central nervous system symptoms or signs (ataxia, sensorineural hearing loss, or cognitive dysfunction).RESULTSAll six patients with neurologic symptoms or signs had multiple abnormal MR findings, whereas patients without neurologic symptoms had either normal MR findings (one patient) or the solitary finding of cortical atrophy (one patient). Abnormal MR findings consisted of cerebral cortical atrophy (seven patients), cerebellar atrophy (six patients), and hyperintense signal abnormalities on T2-weighted images within the cerebral white matter (three patients), cerebellar white matter (one patient), basal ganglia (three patients), brain stem (one patient), and thalamus (one patient). In two patients, the cerebral white matter signal abnormalities were primarily peripheral and involved the arcuate fibers. All patients with ataxia had abnormal cerebellar findings on MR imaging, but there was poor correlation between other neurologic features and MR findings.CONCLUSIONSCerebral and cerebellar atrophy are the most common MR findings in Kearns-Sayre syndrome and chronic progressive external ophthalmoplegia. White matter and deep gray nuclei abnormalities, presumed to result from the diffuse spongiform encephalopathy reported in these patients, can also be seen. Patients with abnormal neurologic findings typically have multiple abnormalities on MR imaging, which frequently do not correlate with specific symptoms.     

Cerebellar and cerebral abnormalities in Rett syndrome: a quantitative MR analysis.

Rett syndrome is a neurodegenerative disease of young girls that begins in early childhood with autismlike behavior and loss of language skills, and progresses with marked deterioration of the motor system in the second decade of life. The purpose of this study was to determine if neuroanatomic changes detected with MR imaging could help to explain the clinical presentation and progression of signs and symptoms in these patients. Accordingly, computer-assisted planimetry was used to measure various dimensions of cerebral, cerebellar, and brainstem structures on sagittal and transverse MR images of 13 patients with Rett syndrome and 10 healthy volunteers. Dimensions of the cerebrum, basal ganglia, cerebellum, and brainstem were measured on transverse images. Areas of cerebellar vermian lobules, the fourth ventricle, the pituitary gland, and the corpus callosum were measured on sagittal images. Fourteen dimensions and areas were measured in each patient and each control subject; according to two-tailed Student's t tests, all but two values were significantly smaller in the patients with Rett syndrome than in control subjects. Graphing the measurements against age by using simple linear regression revealed progressive cerebellar atrophy without evidence of atrophy of the brainstem or cerebrum. Our results indicate that patients with Rett syndrome have global hypoplasia of the brain and progressive cerebellar atrophy increasing with age. Cerebellar atrophy with age may contribute to the deterioration of the motor system seen in older patients with Rett syndrome.     

Profound asphyxia in the premature infant: imaging findings.

PURPOSETo investigate imaging findings in premature infants who had profound asphyxia.METHODSCT (three patients), MR (three patients), and ultrasonography (four patients) studies of five patients who had profound asphyxia before the postconceptional age of 32 weeks were retrospectively reviewed. The patients ranged from 1 day to 4 months old at the time of the imaging studies. An autopsy report was available in one patient. The results were compared with reports in the literature of patients with similar injuries at similar ages.RESULTSAbnormalities of the thalami and basal ganglia were present in all infants examined with CT or MR. CT showed low attenuation in the basal ganglia and high attenuation (blood or calcium) in the thalami; thalamic cavitation and low attenuation of the upper brain stem were present in one infant. MR showed T1 and T2 shortening in the thalami in all patients. Variable MR changes were noted in the basal ganglia, ranging from diminished size with normal signal intensity to T1 and T2 shortening with normal size and complete cavitation. T1 and T2 shortening were seen in the dorsal brain stem in one patient. Sonography showed transient or persistent hyperechogenicity in the thalami in three patients and cavitation of the thalami in one patient. Damage to the perirolandic cortex was not present in any patient.CONCLUSIONProfound asphyxia before 32 weeks gestational age shows consistent injury to the thalami, basal ganglia, and brain stem that can be detected by all three imaging modalities. The pattern of injury seems to differ from that of partial asphyxia in premature infants and of profound asphyxia in term infants.     

MRI of neuronal ceroid lipofuscinosis. II. Postmortem MRI and histopathological study of the brain in 16 cases of neuronal ceroid lipofuscinosis of juvenile or late infantile type

Postmortem MRI was carried out on the formalin-fixed brains of 14 patients with juvenile (JNCL) and two with late infantile neuronal ceroid lipofuscinosis, one of variant and the other of classical type. Two patients with JNCL had also undergone MRI during life. After MRI, specimens for histopathological analysis were taken from standard areas of the cerebral cortex, deep nuclei and white matter. The signal intensity of the periventricular white matter was usually higher than that of the peripheral white matter, a finding which correlated with the severe periventricular loss of myelin and gliosis observed histologically. The signal intensity was usually lower in the thalamus than in the putamen; in some patients the signal intensity of the thalamus was equal to or even lower than that of the white matter. However, myelin loss, gliosis, the storage process or neuronal loss in the thalamus did not correlate with the MRI findings. Since in one patient with JNCL the ante- and postmortem MRI did not differ basically, it appears probable that the periventricular changes detected in vivo on MRI are due to the severe loss of myelin and gliosis observed in this study. However, changes resulting from the fixation process must be considered, when postmortem and in vivo MRI are correlated. Received: 4 May 1994 Accepted: 28 February 1995