Spontaneous dissection of the anterior inferior cerebellar artery

A patient presented with the clinical features of a brain stem infarct. MRI confirmed changes of infarction but also revealed an unusual lesion in the left cerebellopontine angle cistern. The evolution of this lesion on MRI, together with angiographic changes, indicated a dissecting aneurysm of the left anterior inferior cerebellar artery, a previously unreported phenomenon. The presentation, causes and diagnosis of intracranial dissection are discussed. Received: 2 September 1999 Accepted: 16 September 1999     

Proton magnetic resonance spectroscopy of a patient with Gerstmann-Straussler-Scheinker disease

A 23-year-old woman with Gerstmann-Straussler-Scheinker disease (GSS) was investigated by ¹H-magnetic resonance spectroscopy (¹H-MRS). She developed gait ataxic at 22 years. The diagnosis was confirmed by DNA analysis showing a proline-to-leucine point mutation at codon 102 of the prion protein. On ¹H-MRS, she showed a remarkable reduction of the N-acetylaspartate/creatine ratio in the frontal lobe, cerebellar hemisphere and vermis and putamen. MRI revealed mild atrophy of the cerebellar hemispheres and vermis and cerebral cortex, but single-photon emission computed tomography (SPECT) with ^99mHMPAO showed normal perfusion in the cerebellum. The imaging studies suggest that MRS might be superior to MRI or SPECT for detection of early neuronal degeneration. Received: 31 August 1999/Accepted: 10 December 1999     

Síndrome PHACES (Pascual Castroviejo tipo II): resonancia magnética pre y posnatal

The neurocutaneous syndrome known by the acronym PHACE consists of the association of a segmental facial hemangioma with, among other entities, posterior fossa anomalies, cerebrovascular anomalies, cardiac involvement/aortic coarctation, and eye abnormalities. When ventral developmental defects are also present, the syndrome is referred to as PHACES. We report the prenatal and postnatal MRI findings in a case of PHACES with involvement of the right posteroinferior cerebellar artery. This case is exceptional because, to our knowledge, it is the first to report the findings at both prenatal and postnatal MRI and because of the unique vascular anomaly that widens the spectrum of possible intracranial arterial anomalies in this syndrome.     

Blake's pouch cyst: an entity within the Dandy-Walker continuum

Abnormal cerebrospinal fluid (CSF) collections within the posterior fossa are defined by the Dandy-Walker complex (DWC) and by arachnoid cysts (AC). The DWC includes the Dandy-Walker malformation (DWM), the Dandy-Walker variant (DWV) and the mega-cisterna magna (MCM). In addition, Tortori-Donati et al. added persistent Blake's pouch cyst (BPC) as an independent entity within the DWC. BPC represents a posterior ballooning of the superior medullary velum into the cisterna magna. All of these malformations are overlapping developmental anomalies characterized by varying degrees of malformation of the medullary vela, the cerebellar vermis and hemispheres, the fourth ventricle choroid plexus, the posterior fossa subarachnoid cisterns and the enveloping meningeal structures. We present two cases of persistent BPC detected in two adult women without history of gestational or subsequent growth problems. They underwent neuroradiological investigation because of headache and because of recurrent episodes of loss of consciousness, respectively. The MRI findings included tetraventricular hydrocephalus, wide communication of the fourth ventricle and the cystic posterior fossa (i. e. BPC), inferior posterior fossa mass effect with or without hypoplasia of both the cerebellar vermis and the medial aspects of the cerebellar hemispheres, and absence of communication between fourth ventricle and the basal subarachnoid space in the midline posteriorly. Persistent BPC is defined by a failure of embryonic assimilation of the area membranacea anterior within the tela choroidea associated with imperforation of the foramen of Magendie. Typically this condition becomes symptomatic early in life. In the current cases the normal function of the laterally positioned foramina of Luschka probably helped to maintain some CSF flow between intraventricular and subarachnoid spaces, with the establishment of a precarious equilibrium characterized by a compensatory enlargement of the cerebral ventricular system (i. e. hydrocephalus). Received: 2 July 1999 Accepted: 13 July 1999     

Primary brain lymphoma presenting as Parkinson's disease

Neoplasm is an uncommon cause of a parkinsonian syndrome. We report a woman with primary brain B-cell lymphoma presenting as Parkinson's disease. After 1 year of the illness, CT and MRI showed lesions without mass effect in the basal ganglia and corpus callosum. The patient did not respond to levodopa and right cerebellar and brain-stem signs appeared, which prompted further neuroimaging, showing an increase in size of the lesions and a right cerebellar and pontine mass. Stereotactic biopsy of the basal ganglia showed high-grade B-cell lymphoma. Despite the basal ganglia frequently being involved in lymphoma of the brain, presentation with typical or atypical parkinsonism is exceptional. Received: 17 September 1999/Accepted: 26 June 2000     

Unusual pattern of leukoencephalopathy after morphine sulphate intoxication

We report a 14-year-old girl with an unusual pattern of leukoencephalopathy after intentional intoxication with morphine sulphate tablets. Toxicological analysis showed exceedingly high levels of morphine and its metabolites. MRI disclosed a leukoencephalopathy with high signal from the centrum semiovale, corpus callosum and cerebellar white matter on T2-weighted images. These findings could be only partially explained by a hypoxic-ischaemic event; neurotoxic effects must be considered in this atypical leukoencephalopathy. Received: 3 August 1999 Accepted: 3 April 2000     

Lhermitte-Duclos disease: MR diffusion and spectroscopy

AIM: To describe two cases of Lhermitte-Duclos disease studied with Diffusion MRI and MRi Spectroscopy. MATERIALS AND METHODS: Two patients showing a space-occupying lesion in the cerebellar hemisphere were studied by conventional MRI associated with Diffusion MRI and Spectroscopy. RESULTS: Conventional MRI showed the typical morphological pattern of Lhermitte-Duclos disease with a slow-growing cerebellar mass mainly involving the cortex and non-enhancing thickened cerebellar folia. The mass exerted mild compression of the IV ventricle causing hydrocephalus On Diffusion imaging showed the lesion to be hyperintense due to residual T2-activity and hypointense on the ADC map. Spectroscopy was typical with an increased lactate peak and a reduced choline peak, indicating abnormal anaerobic glycolysis and demyelination, respectively. DISCUSSION: Lhermitte-Duclos disease is a neurological condition which presents several signs and symptoms related to the cerebellar mass. Cowden's syndrome, an autosomal dominant neoplastic disorder with malignant features is associated in 40% of cases. MRI associated with functional examinations such as Diffusion Imaging and Spectroscopy is the imaging modality of choice in LDD patients. They allow a definite diagnosis as the neuroradiological findings correlate well with molecular biology theories regarding the malformative nature of dysplastic cerebellar gangliocytoma.     

小脑半球肿瘤的MRI诊断与鉴别诊断

目的:分析小脑半球肿瘤的MRI表现及鉴别诊断。方法:回顾性分析42例经手术及病理证实的小脑半球肿瘤的MRI表现。结果:星形细胞瘤15例,单发转移性肿瘤10例,血管母细胞瘤8例,髓母细胞瘤6例,恶性淋巴瘤2例,室管膜瘤1例。结论:MRI能清晰显示小脑半球肿瘤的部位、大小、形态、信号强度和边缘等特征,具有重要的诊断价值。     

Dandy-Walker综合征的MRI诊断(附6例报告)

目的:探讨Dandy-Walker综合征(DWS)的临床及MRI表现特征。方法:对6例经MRI诊断为DWS进行回顾性分析。结果:MRI主要表现为小脑蚓部缺如,小脑半球部分发育不全伴分离、移位;第四脑室囊状扩大与后颅窝囊腔相通;后颅窝扩张伴有横窦、窦汇和小脑幕上移;常伴有幕上不同程度梗阻性脑积水及其他颅内畸形。结论:DWS的MRI表现具有特征性,MRI是诊断DWS的最理想的影像学方法。     

MRI of acute and chronic aortic pathology: pre-operative and postoperative evaluation.

With recent advances in the understanding of aortic diseases, both power and versatility have put magnetic resonance imaging (MRI) in the focus of diagnostic work-up in the entire spectrum of clinical aortic pathology. Technical refinements, from classic anatomic imaging to three-dimensional gadolinium-enhanced MR angiography and tissue characterization, have rendered MRI ideal for assessment of acquired disease such as aortic dissection, intramural hematoma, and aneurysm, along with postoperative follow-up evaluation, with better reliability and safety than other imaging modalities. Moreover, congenital pathology of the aorta, including aortic arch anomalies and coarctation, can be non-invasively evaluated by MRI. With spectroscopy and the advent of high-resolution intravascular coils, MRI may even provide histopathologic and potentially prognostic information unparalleled by any other method. J. Magn. Reson. Imaging 1999;10:741-750.     

MRI of Wolfram syndrome (DIDMOAD)

Wolfram syndrome (DIDMOAD) is a rare diffuse neurodegenerative disorder characterised by diabetes insipidus, diabetes mellitus, optic atrophy, deafness, and a wide variety of abnormalities of the central nervous system, urinary tract and endocrine glands. It may be familial or sporadic. Reported features on MRI of the brain are absence of the physiological high signal of the posterior lobe of the pituitary, shrinkage of optic nerves, chiasm and tracts, atrophy of the hypothalamic region, brain stem, cerebellum, and cerebral cortex. We report a 12-year-old girl with a 5-year history without brain stem, cerebellar or cerebral atrophy. MRI showed an unusual feature: a focus of high signal on PD- and T2-weighted images in the right substantia nigra. This is consistent with previously reported neuropathological post-mortem studies, but has never been reported in vivo. Received: 23 November 1998 Accepted: 23 March 1999     

小脑髓母细胞瘤的MRI表现

目的：探讨小脑半球髓母细胞瘤的MRI表现,提高对髓母细胞瘤的认识。方法：8例经手术病理证实的小脑半球髓母细胞瘤患者,男5例,女3例,年龄1～33岁,所有病例均行MRI平扫及增强扫描,其中2例行CT平扫,回顾性分析其临床及影像学表现。结果：肿瘤位于小脑半球深部4例,小脑半球表面且突向桥小脑角区2例,双侧小脑半球及小脑蚓部多发病灶2例。肿瘤内发生囊变5例,囊变区大小不一,3例位于肿瘤周边,2例位于中央,其内壁光滑。MRI平扫肿瘤实性部分T1W1呈稍低信号,T2WI呈等信号或稍高信号,且信号不均匀,5例肿瘤周围有轻度水肿。增强扫描3例肿瘤有轻度强化,5例中度强化,其中1例有脑回状强化。2例CT平扫示肿瘤呈稍高密度。结论小脑半球髓母细胞瘤的MRI表现具有一定特征性,MRI检查对诊断本病有重要价值。     

Cerebral venous drainage via the ophthalmic veins in the Sturge-Weber syndrome

We describe a 23-year-old girl with an extremely uncommon form of cerebral venous drainage and cerebellar leptomeningeal angiomatosis as a possible variant of the Sturge-Weber syndrome. Extensive congenital portwine stains all over the body, hypoplastic left renal and subclavian and iliac veins, cardiomegaly and ptosis and hypoplasia of the left kidney had been recognised in early childhood. She rapidly developed signs of intracranial hypertension. CT and MRI showed a right medial temporal lesion. Angiography revealed cerebellar pial angiomatosis with enlarged medullary veins and no functioning sigmoid sinuses or jugular veins. Cerebral venous drainage was via enlarged ophthalmic veins. Although the intracranial venous abnormalities were characteristic of the Sturge-Weber syndrome anomalies beyond the encephalofacial territory suggested a more complex developmental abnormality.     

Klippel-Trenaunay syndrome: frequency of cerebral and cerebellar hemihypertrophy on MRI

We examined 11 patients, clinically and radiographically diagnosed as having the Klippel-Trenaunay syndrome (KTS) by MRI. There were four females and seven males, aged 3–51 years (mean 21 years). Two had clear asymmetry of the cerebral and cerebellar hemispheres. The thickness of the grey matter was normal, without sulcation abnormalities, but the thickness of the white matter was increased; the size of the ipsilateral ventricle was normal. These patients had hypertrophy of the leg and a cutaneous haemangioma on the same side as the brain abnormality. No patient had an intracranial vascular malformation, unilateral megalencephaly, cerebral atrophy or hydrocephalus. The prevalence of cerebral hemihypertrophy in our series of patients with KTS was thus 18 %. Received: 15 March 1999/Accepted: 30 August 1999     

胎儿Dandy-Walker综合征的MRI研究

目的探讨胎儿Dandy-Walker综合征(Dandy-Walker syndrome,DWS)的MRI表现。方法对23例胎儿DWS病例进行回顾性分析。结果胎儿DWS主要表现为小脑蚓部缺如或发育不良,第四脑室扩大与后颅窝囊肿相通或小脑延髓池增宽。结论 DWS的MRI表现具有特征性,是诊断DWS的最理想的影像学方法。     

MRI of the brain in the Kearns- Sayre syndrome: report of four cases and a review

We report brain MRI findings in four patients with typical Kearns-Sayre syndrome (KSS) and correlate them with clinical manifestations. MRI was interpreted as normal in two patients; cerebral and cerebellar atrophy was seen in the other two. On T2-weighted spin-echo images, two patients had high-signal lesions bilaterally in subcortical white matter, thalamus and brain stem. In one patient, the white matter lesion extended into the deep cerebral white matter and the cerebellum was also affected. The other also had bilateral high-signal lesions in the globus pallidus. There was little correlation between neurological deficits and MRI findings. A review of the literature revealed that 10 of the 13 patients with typical KSS previously studied had bilateral subcortical white-matter lesions on T2-weighted images; at least 7 also had high-signal lesions in the brain stem, globus pallidus, thalamus or cerebellum. Although MRI may be normal or show atrophy, the characteristic finding in KSS is a combination of the high-signal foci in subcortical cerebral white matter and in the brain stem, globus pallidus or thalamus. Received: 23 October 1998 Accepted: 8 February 1999     

髓母细胞瘤的CT和MRI诊断

目的：提高非典型髓母细胞瘤的CT和MRI的诊断准确率。材料和方法：经手术及病理证实的髓母细胞瘤40例，年龄5～35岁。CT检查34例，其中28例同时作增强扫描。MRI检查38例，30例作增强扫描。32例同时作CT和MRI检查。结果：CT和MRI对髓母细胞瘤的定位诊断正确率为100％，定性诊断正确率为87．5％（35／40）。肿块位于小脑蚓部25例，小脑半球9例，四脑室内6例。肿瘤囊变26例，钙化3例，有例增强不明，3例出现转移，转移沿脑脊液播散。结论：非典型髓母细胞瘤可以发生在四脑室内，小脑半球，可以出现大的囊变、钙化，也可以增强不明显，掌握这些征象是CT和MRI诊断非典型髓母细胞瘤的关键。     

MRI of fetal genitourinary anomalies

OBJECTIVE: The objective of our study was to show examples of fetal MRI evaluations of congenital genitourinary anomalies and to review the embryology in relation to the MRI findings. CONCLUSION: MRI was performed on 35 pregnant women with sonographic findings that suggested that their fetuses had genitourinary anomalies. Oligohydramnios or anhydramnios was identified in 22 of 35 women and did not hinder visualization of anomalies. MRI allowed the amniotic fluid and the presence, location, and morphology of kidneys and bladder to be assessed in all fetuses at any stage of gestation and depicted sufficient anatomic detail for us to evaluate the perineum in 27 of 35 pregnancies. Therefore, we found MRI to be an excellent technique for revealing the anatomy of genitourinary anomalies in the fetus.     

Magnetic resonance imaging findings of Machado-Joseph disease: histopathologic correlation

PURPOSE: To determine the characteristic magnetic resonance imaging (MRI) findings of early- and late-stage Machado-Joseph disease (MJD) and to examine correlation with pathologic specimens. PATIENTS AND METHODS: Four patients genetically diagnosed with MJD and a familial case of MJD were all examined using MRI. Machado-Joseph disease was pathologically confirmed in one of the four genetically diagnosed patients, and the findings were compared with the MRI results. RESULTS: In all three patients who had MJD for less than 8 years, MRI confirmed mild cerebellar atrophy, particularly in the vermis, and atrophic changes in the superior cerebellar peduncle. Mild pontine atrophy was observed in these three patients. Atrophic changes in the pontine tegmentum were more prominent than those of the pontine base in these patients. Two of the three patients showed mild frontal atrophy. Of the five total patients, two had the disease for over 10 years and showed progressive atrophy of the brainstem and mild frontal atrophy. These two patients also showed pallidal atrophy. One autopsied case in which the disease duration was 17 years showed a typical pathologic picture of MJD. Macroscopic findings for this patient showed marked atrophy of the pons, mild cerebellar atrophy (particularly in the vermis), marked atrophy of the superior cerebellar peduncle, severe involvement of motor nuclei, and atrophy and discoloration of the pallidum and subthalamic nuclei. CONCLUSION: In the early stages of MJD, mild pontine atrophy, particularly in the tegmentum, and mild cerebellar atrophy are typical MRI findings. Atrophic changes in the brainstem may be progressive. Pallidal atrophy may be observed in patients with long disease duration. These findings correlated with the pathologic findings.     

An MRI analysis of brain-stem and cerebellar lesions and olivary hypertrophy

We describe the relations between primary brain stem or cerebellar infarct or haemorrhage and secondary inferior olivary pseudohypertrophy (OPH). We identified 17 patients (43.6%) among 39 with brain stem or cerebellar vascular disease who had MRI follow-up more than 3 months after their ictus, with OPH. The primary lesions in the 22 cases without OPH were 11 haemorrhages, including 8 medial cerebellar and 3 brain stem lesions, and 11 infarcts: 4 brain stem lesions without accompanying cerebellar involvement, 2 cerebellar infarcts with brain stem extension, and 5 cerebellar lesions without a brain stem infarct. The causative lesion in the 17 patients with OPH included 5 brain stem and 7 cerebellar haemorrhages and 5 brain stem infarcts; no cerebellar infarcts without brain stem involvement were found to cause OPH. Primary involvement of the tegmentum of the brain stem was closely related to secondary OPH, but we could not characterise MRI differences in the cerebellar lesions between the patients with or without OPH.