CT scan appearances in Leigh's disease (subacute necrotizing encephalomyelopathy)

Summary Four cases of Leigh's disease (subacute necrotizing encephalomyelopathy), two confirmed at postmortem examination, have been investigated recently by CT scanning. All four showed the same symmetrical areas of low attenuation in the basal ganglia, especially the putamina. These areas corresponded with the typical areas of necrosis seen in this disease. There was also some evidence of atrophic change in the posterior fossa in some cases. This CT scan appearance may be diagnostic in the appropriate clinical context.     

Leigh's subacute necrotizing encephalomyelopathy: Possible diagnosis by CT scan

Summary A 28-month-old Korean girl developed a rapidly progressive disease, characterized by disturbance of consciousness, tremor, nystagmus, ophthalmoplegia, irregular deep respiration and vomiting. The patient succumbed 2 weeks after the onset of the illness. CT scan disclosed bilaterally symmetrical, low density lesions in the white matter and lateral basal ganglia. Distinctive histopathological findings at postmortem included spongiotic necrosis of the neuropil, marked capillary vascularity, persistence of relatively normal neurons in severely damaged zones, and comparatively little astrocytosis. The bilaterally symmetrical distribution of these changes in the putamen and periaqueductal gray matter of the midbrain were compatible with Leigh's disease.     

MR findings in patients with subacute necrotizing encephalomyelopathy (Leigh syndrome): correlation with biochemical defect

MR studies were correlated with biochemical results in nine children who presented with lactic acidosis and/or abnormal MR findings in the basal ganglia. Neurologic development was delayed in all nine children. Seven of these patients were diagnosed as having subacute necrotizing encephalomyelopathy (SNE, or Leigh syndrome) on the basis of history, clinical findings, and biochemical studies; of the remaining two, one had congenital lactic acidosis and the other had familial bilateral striatal necrosis with no known biochemical correlate. Although the clinical presentation of these patients was similar, we found distinctive MR abnormalities in characteristic locations in the seven patients with SNE, with or without detectable specific mitochondrial enzyme deficiency in cultured skin fibroblast assays. In our case studies of SNE patients with detectable enzyme deficiency states, defects in pyruvate dehydrogenase complex and cytochrome c oxidase have been found. The MR finding of note in SNE is the remarkably symmetrical involvement, most frequently of the putamen. In our study, lesions were also commonly found in the globus pallidus and the caudate nucleus, but never in the absence of putaminal abnormalities. Other areas of involvement included the paraventricular white matter, corpus callosum, substantia nigra, decussation of superior cerebellar peduncles, periaqueductal region, and brainstem. In patients who present with lactic acidosis and whose MR findings show symmetrical abnormalities in the brain, but with sparing of the putamen, the diagnosis of SNE is in doubt.     

MR findings in patients with subacute necrotizing encephalomyelopathy (Leigh syndrome): correlation with biochemical defect

MR studies were correlated with biochemical results in nine children who presented with lactic acidosis and/or abnormal MR findings in the basal ganglia. Neurologic development was delayed in all nine children. Seven of these patients were diagnosed as having subacute necrotizing encephalomyelopathy (SNE, or Leigh syndrome) on the basis of history, clinical findings, and biochemical studies; of the remaining two, one had congenital lactic acidosis and the other had familial bilateral striatal necrosis with no known biochemical correlate. Although the clinical presentation of these patients was similar, we found distinctive MR abnormalities in characteristic locations in the seven patients with SNE, with or without detectable specific mitochondrial enzyme deficiency in cultured skin fibroblast assays. In our case studies of SNE patients with detectable enzyme deficiency states, defects in pyruvate dehydrogenase complex and cytochrome c oxidase have been found. The MR finding of note in SNE is the remarkably symmetrical involvement, most frequently of the putamen. In our study, lesions were also commonly found in the globus pallidus and the caudate nucleus, but never in the absence of putaminal abnormalities. Other areas of involvement included the paraventricular white matter, corpus callosum, substantia nigra, decussation of superior cerebellar peduncles, periaqueductal region, and brainstem. In patients who present with lactic acidosis and whose MR findings show symmetrical abnormalities in the brain, but with sparing of the putamen, the diagnosis of SNE is in doubt.     

亚急性坏死性脑脊髓病的磁共振成像

目的:探讨磁共振成像(MRI)对亚急性坏死性脑脊髓病的诊断价值。方法:收集我院确诊为亚急性坏死性脑脊髓病患者6例,回顾性分析其MRI表现。结果:6例患者均出现双侧豆状核对称性异常信号,T1WI呈低信号,T2WI呈高信号,T2-FLAIR呈混杂信号,无占位效应,增强扫描病灶无强化。结论:亚急性坏死性脑脊髓病最常累及双侧豆状核,其MRI表现具有特征性,结合临床容易诊断。     

Mechanisms of unexpected death and autopsy findings in Leigh syndrome (subacute necrotising encephalomyelopathy)

A 21-year-old previously-well woman who was undergoing medical investigations for problems with balance and suspected multiple sclerosis, developed a headache and breathing difficulties, and died suddenly and unexpected at home. The autopsy was unremarkable except for pulmonary and cerebral oedema. However, subsequent microscopy of the brain revealed characteristic features of Leigh syndrome with multifocal areas of astrogliosis, capillary proliferation, and parenchymal vacuolation. While Leigh syndrome is more commonly diagnosed in infancy, manifestations may occur throughout early life into adulthood. Sudden and unexpected death is a rare presentation that may be associated with cerebral necrosis and oedema. An awareness of the variable manifestations of Leigh syndrome is necessary in forensic practice as not all cases will present in a typical manner and sudden death may occur before a diagnosis has been established. The heritable nature of this condition makes accuracy of diagnosis essential.     

Uncommon morphologic characteristics in Leigh's disease.

We describe a 4-month-old male patient with severe developmental delay and elevated lactate in blood and CSF. The MR images showed abnormalities differing from the typical pattern found in association with Leigh's disease. The examination of fibroblast cultures showed diminished activity of mitochondrial complexes I and III. The patient died at the age of 9 months.     

脊髓亚急性联合变性的MRI诊断要点分析

目的分析脊髓亚急性联合变性(SCD)的MRI诊断要点。资料与方法回顾性分析15例临床确诊SCD的病人临床及MRI资料,分析其脊髓MRI表现特点,统计分析SCD病人受累脊髓节段数与血清VB12水平、发病时间的相关性。结果 15例SCD病人均于横断面影像上显示颈胸段脊髓对称性等或长T1、长T2信号,13例病变主要位于颈胸段水平脊髓后索,2例同时累及后索、侧索及前索。但于横断面T2WI上颈段与胸段脊髓异常信号形态各具特点。颈段脊髓受累时于横断面T2WI上呈脊髓内"倒V"形或"反兔耳"形的对称性高信号。胸段脊髓受累时于横断面T2WI上呈脊髓内"哑铃"形的对称性高信号。统计学分析显示15例SCD病人脊髓受累节段数与血清VB12水平呈负相关,而与病程长短无相关性。结论脊髓MR成像对于SCD脊髓疾病的诊断有重要价值。     

Diffusion-weighted MR imaging findings of acute necrotizing encephalopathy

Multiple, symmetrical brain lesions affecting the bilateral thalami and cerebral white matter, which often show a concentric structure on CT and MR images, characterize acute necrotizing encephalopathy (ANE) of childhood. We describe the imaging findings of a 2-year-old child with ANE obtained with diffusion-weighted MR imaging. We discuss the significance of these findings, as well as the pathophysiology of ANE lesions, with reference to the appearance of the disease as revealed by diffusion-weighted MR imaging.     

MR imaging vs CT in subacute sclerosing panencephalitis

The MR findings in three patients with subacute sclerosing panencephalitis were reviewed and compared with CT findings in the same patients. Long-T2 lesions were demonstrated in each case, although their distribution varied with the clinical stage of the disease. MR, especially T2-weighted imaging, appears to be of great utility in the assessment of subacute sclerosing panencephalitis.     

Acute and subacute ischemic stroke at high-field-strength (3.0-T) diffusion-weighted MR imaging: intraindividual comparative study

PURPOSE: To compare signal-to-noise ratios (SNRs), contrast-to-noise ratios (CNRs), image quality, and confidence in diagnosis between 1.5- and 3.0-T diffusion-weighted (DW) magnetic resonance (MR) imaging of ischemic stroke lesions. MATERIALS AND METHODS: The study design was approved by the institutional review board, and all patients gave informed consent. In a prospective intraindividual study, 25 patients who had clinical symptoms consistent with ischemic stroke underwent DW MR imaging at both 1.5 T and 3.0 T. The 3.0- or 1.5-T examination was performed immediately one after the other, in random order. Two readers in consensus recorded the presence and number of ischemic lesions and rated image quality and lesion conspicuity. The image SNR and the CNR of the ischemic lesions were quantified. Paired Student t and Wilcoxon matched-pairs signed rank tests were used to test for statistical significance. RESULTS: Image quality at 3.0-T DW MR imaging was consistently lower than that at 1.5-T DW MR imaging owing to greater image distortions (P < .05). Yet, overall SNR and lesion CNR at 3.0 T increased significantly; mean increases were 48.8% (P < .001) and 96.3% (P < .01), respectively. The higher overall SNR and lesion CNR translated into a significantly higher sensitivity in the detection of ischemic lesions at 3.0 T than at 1.5 T. Of the total of 48 lesions that were identified in 19 of the 25 patients, 47 (98%) were diagnosed at 3.0 T and 36 (75%) were diagnosed at 1.5 T. In addition, the conspicuity of the lesions that were visible with both systems was significantly higher at 3.0 T (P < .001). CONCLUSION: Although 3.0-T DW MR imaging generates greater image distortions, it yields increased SNR and CNR compared with DW MR imaging at 1.5 T. The increased CNR at 3.0 T translates into a significantly improved diagnostic confidence in the detection of focal apparent diffusion coefficient changes in the setting of subacute and acute ischemic stroke.     

Iodine-123 HIPDM brain imaging findings in subacute spongiform encephalopathy (Creutzfeldt-Jakob disease)

Decreased perfusion of the left frontal and left temporoparietal cortex has been shown in [123I] HIPDM planar and single photon emission computed tomographic images of a patient with Creutzfeldt-Jakob disease (CJD) that was proven by brain biopsy and subsequent autopsy. An EEG showed diffuse, periodic discharges most prominent to the left hemisphere. Concurrent head computed tomography (CT), nuclear magnetic resonance (NMR), and cerebral angiographic studies were negative. Abnormalities demonstrated by [123I]HPDM imaging and by EEG may represent changes in neurophysiological and neurochemical status while cerebral angiography, CT, and possibly NMR register only anatomic or structural lesions. Premortem diagnosis of CJD depends on brain biopsy; the availability of the [123I] HIPDM study may provide regional cerebral neurochemical and neurophysiological information, guiding or avoiding brain biopsy in the appropriate clinical setting.     

MRI对脊髓亚急性联合变性的诊断价值

目的 评价ＭＲＩ诊断脊髓亚急性联合变性（ＳＣＤ）的价值。方法 ７例维生素Ｂ１２缺乏而临床怀疑ＳＣＤ的患者进行了ＭＲ扫描。扫描包括矢状面Ｔ１ＷＩ和矢状面、轴面Ｔ２ＷＩ,其中４例行钇喷替酸葡甲胺（Ｇｄ－ＤＴＰＡ）增强扫描,４例于治疗后行ＭＲＩ复查结果所有病例的Ｔ２ＷＩ均显示。戏髓或胸髓后索高倍病灶,有４例同时出现侧索病灶,Ｔ１ＷＩ未见异常,Ｇｄ－ＤＴＰＡ增强鞠强化。有４例在维生素Ｂ１２治疗后半年及１年     

CT and MR imaging findings associated with subacute thyroiditis

Subacute granulomatous thyroiditis is an uncommon disease that occurs most often in women in their second to fifth decades of life. This disease usually presents with thyroid tenderness, a low grade fever, and occasional dysphagia. The disease resolves spontaneously, usually without thyroid function abnormalities. We herein present the CT and MR imaging findings of two cases of subacute granulomatous thyroiditis.     

Variable appearances of subacute intracranial hematomas on high-field spin-echo MR

Subacute intracranial hematomas have variable appearances on high-field MR images. They are hyperintense on T1-weighted images owing to methemoglobin, but have variable intensities on T2-weighted images. Observation of the different high-field spin-echo MR intensity patterns of five subacute hematomas suggests that further subcategorization into different methemoglobin states may be possible. In particular, undiluted intracellular methemoglobin is hyperintense on T1-weighted images and markedly hypointense on T2-weighted images, undiluted free methemoglobin should be hyperintense on T1-weighted images and isointense or slightly hypointense on T2-weighted images, and dilute free methemoglobin is hyperintense on both T1- and T2-weighted images. However, it appears that certain regions of subacute hematomas may be difficult to differentiate, by intensity patterns alone, from melanotic melanomas or fat. We believe that, despite some limitations, MR is useful in dividing subacute intracranial hematomas into their respective methemoglobin states, and also that further subcategorization is possible.     

烟雾病MRI和MRA诊断价值(附16例报告)

目的；评价MRI和MRA对烟雾病的诊断价值。方法：分析16例烟雾病患者的MRI、MRA表现和临床资料。MRA采用三维时间飞跃法。结果：16例患者MRA检查均显示不同程度的颈内动脉分叉以上狭窄或闭塞，其中17支后交通动脉增粗，4支眼动脉增粗；16例显示基底节区异常血管网，其中6例同时显示后部异常血管网；10例显示软脑膜吻合支增多；MRI显示脑出血或脑梗塞等脑实质改变，并能显示基底节区异常血管点状流空。结论：MRI和MRA是诊断烟雾病的有效非创伤性检查方法。对该病的诊断、筛选、随访和外科5一的评价有较大价值。     

Proton MR spectroscopy in the diagnosis of early-stage subacute sclerosing panencephalitis

Subacute sclerosing panencephalitis (SSPE) is a progressive, fatal neurological disorder of childhood and early adolescence. In this report, we present brain magnetic resonance spectroscopy (MRS) and conventional magnetic resonance MR imaging findings of early-stage (stage II) SSPE in an 8-year-old child. MRS demonstrated increased myo-inositol/creatine and choline/creatine ratios, and a decreased N-acetyl aspartate/creatine ratio. Conventional MR imaging demonstrated nonspecific, patchy T2 hyperintensities in the periventricular white matter and a nonspecific focus of T2 hyperintensity in the right frontal subcortical white matter. The MRS findings suggested active inflammation and demyelination as is seen in early-stage SSPE.