Hoyeraal-Hreidarsson syndrome: magnetic resonance imaging findings

Hoyeraal-Hreidarsson syndrome (HH) has been defined as a severe variant of dyskeratosis congenita (DKC). We report here a case of a 6-year-old girl with HH who presented with bone marrow hypoplasia, skin pigmentation, nail dystrophy, growth retardation, and bilateral retinal hemorrhage. Brain MRI revealed cerebellar hypoplasia, hypoplasia of the corpus callosum, a small pituitary gland, a small brain stem, and focal long T2 lesions in the thalamus and brain stem. A brain computed tomography scan revealed intracranial calcification as well. To the best of our knowledge, a small pituitary gland and focal long T2 lesions in the thalamus and brain stem have never been reported as a feature of HH.     

MRI in cerebellar hypoplasia

Cerebellar hypoplasia may present with a wide variety of neurological and systemic features, ranging from aplasia causing neonatal death to mild hypoplasia in an asymptomatic adult. MRI clearly documents the size of the cerebellum and any associated abnormalities. We describe 7 cases of cerebellar hypoplasia of varying aetiology-3 inherited, 2 associated with spinal dysraphism, 1 with Joubert's syndrome and 1 with pontine agenesis, probably as a result of basilar artery infarction in utero. T1- and T2-weighted images were obtained in each case and gadolinium-DTPA was administered in one. Associated features such as a Chiari malformation (2 cases), brain stem hypoplasia (2 cases), Dandy-Walker cyst and pachygyria (3 cases) and spinal dysraphism (2 cases) were clearly identified. Accurate documentation of these appearances assists in genetic counselling.     

Neonatal pontomedullary disconnection with aplasia or destruction of the lower brain stem: a case of pontoneocerebellar hypoplasia?

We report a neonate who presented with marked hypotonia and absent suck reflex. MR demonstrated complete absence of the pons as well as absence of a basilar artery flow void. Our case exhibits features similar to those described in previous reports of pontoneocerebellar hypoplasia, but with a more severe degree of pontine involvement. The associated vascular findings suggest a vascular insult to the brain stem as the cause.     

Wolfram syndrome presenting marked brain MR imaging abnormalities with few neurologic abnormalities

Wolfram syndrome is a rare autosomal recessive disorder featuring diabetes insipidus, diabetes mellitus, optic atrophy, and deafness; DIDMOAD is a commonly accepted anonym for this disorder. We describe a 35-year-old man with Wolfram syndrome, who had marked atrophy of the brain stem, middle cerebellar peduncle, and cerebellum. Despite these MR imaging findings involving the pontocerebellar tract, the patient had no neurologic abnormalities suggesting dysfunction of the brain stem or cerebellum. Patients with Wolfram syndrome may have discrepancies between neurologic and radiologic findings.     

Posterior cranial fossa tumours in childhood

We reviewed clinical and CT findings in 133 posterior cranial fossa tumours in children. All had histological diagnosis, apart from 20 cases of brain stem glioma. The majority were intra-axial tumours, including 53 medulloblastomas (40%), 31 cerebellar astrocytomas (23%), 28 brain stem gliomas (21%), 14 ependymomas (11%), and single cases of ganglioglioma, haemangioblastoma and teratoma. Extra-axial tumours formed only 3%, including 2 chordomas and 2 schwannomas. The clinical data and CT findings are reviewed. Cerebellar astrocytoma involved the sexes equally, while medulloblastoma, brain stem glioma, and ependymoma were more common in males. Most cerebellar astrocytomas were in the midline, and presumably arose from the vermis. The frequency of calcification was similar to that in previous reports, being highest in ependymoma (69%), followed my medulloblastoma (29%), cerebellar astrocytoma (17%), and brain stem glioma (8%).     

Leigh syndrome: serial MR imaging and clinical follow-up

BACKGROUND AND PURPOSE: Subacute necrotizing encephalomyelopathy, or Leigh syndrome (LS), is a progressive neurodegenerative disorder characterized by symmetrical spongiform lesions in the brain with onset usually in infancy or early childhood. Little is known of the developing process of the brain lesions in LS that are particularly relevant to the occurrence of fatal respiratory failure. Our purpose was to determine whether fatal respiratory failure can be predicted before death on the basis of clinical characteristics or findings on longitudinal MR images of the brain. METHODS: Clinical records and serial MR studies of eight patients with LS aged 3 months to 12 years who met the diagnostic criteria for LS were reviewed retrospectively, with special reference to a correlation between loss of respiratory control and MR abnormalities. Both T1- and T2-weighted images were obtained at the onset of disease or when clinical symptoms worsened. RESULTS: Serial MR images were divided into three groups on the basis of the following findings: 1) symmetrical basal ganglia lesions before brain stem involvement (n = 4); 2) initial involvement of the brain stem (n = 2); and 3) cerebral white matter lesions followed by brain stem lesions (n = 2). Lesions of the lower brain stem were always present when patients had near fatal respiratory failure. However, upper brain stem lesions were transient and were found in parallel to reversible respiratory disorder. Fatal respiratory failure was unpredictable from clinical or neuroradiologic findings. CONCLUSION: Brain stem lesions are associated with the loss of respiratory control in patients with LS, but the time at which fatal respiratory failure will occur is unpredictable.     

Developmental venous anomalies of the posterior fossa with transpontine drainage: report of 3 cases

Developmental venous anomalies (DVA) are considered as variant patterns of cerebral venous drainage. Although generally not rare in the cerebellum, DVA of the brain stem or of the cerebellum with drainage through the brain stem are exceptional findings. Because it is not clear whether DVA may sometimes be of clinical significance, we try to correlate the clinical findings of the patients with the course of the variant vessels. We reviewed the literature and report three additional cases. All patients were examined by MRI and digital subtraction angiography. In particular, we discuss the drainage route as compared with the established patterns of posterior fossa blood drainage, which is directed to the dural sinuses, the petrosal vein or the vein of Galen. In one of our patients suffering from trigeminal neuralgia, the close topical relation of the DVA and the trigeminal nucleus and trigeminal nerve entry zone suggests a causal relationship. In a second case the brain stem symptoms were due to haemorrhage of a concomitant cavernoma. It remains unclear if the occurrence of dysarthria and dysaesthesia in the third patient with brain stem DVA was purely coincidental. The only clinical symptom directly attributable to a DVA with transpontine drainage in our series was trigeminal neuralgia. Received 11 April 1996; Revision received 8 August 1996; Accepted 2 October 1996     

Joubert-Plus syndrome with an atretic cephalocele: a case report

Joubert syndrome is a rare heterogeneous disease affecting the cerebellum. It usually presents with hypotonia, abnormal breathing pattern, with distinctive cerebellar and brain stem malformation called the molar tooth sign. It may present with different organ involvement or with other neurological alterations such as Dandy-Walker syndrome. Joubert syndrome with dandy walker syndrome is called Joubert-Plus syndrome, an exceedingly rare entity. Dandy-Walker syndrome is defined by hypoplasia and upward rotation of the cerebellar vermis and cystic dilation of the fourth ventricle. Atretic cephalocele is another rare diagnosis which is characterized by a herniation of intracranial contents through a skull defect. Herein, we present a case of a 6-month-old patient who presented with floppiness and a scalp nodule. After further evaluation, he was diagnosed with Joubert-Plus syndrome with an atretic cephalocele.     

Resistive NMR of brain stem gliomas

Summary The NMR and CT findings in 22 patients with primary brain stem tumors were compared to determine the value of each study in identifying, and delineating the extent and relationships of the tumor to brain anatomy. NMR was found to be distinctly superior to CT in showing involvement of the medulla and upper cervical cord. NMR eliminates the need for intrathecal enhanced metrizamide CT, and in the future should be the only initial diagnostic test needed for the evaluation of intrinsic brain stem tumors.     

磁共振在脑干损伤急性期诊断及预后判断中的价值

目的 研究脑干损伤患者在急性期(伤后7 d内)的头颅CT和MRI表现特点,以及头颅MRI表现与预后之间的关系,为脑干损伤患者提供影像学诊断依据和预后评价指标.方法 收集本院2007年11月-2008年9月临床确诊为脑干损伤的患者作为研究对象.在脑干损伤早期对其进行头颅CT和MRI检查,伤后随访6个月,根据Barthal指数和残疾分级评分(DRS)来评价患者的预后及生存质量.结果 急性期头颅MRI对脑干损伤的发现率明显高于头颅CT,而且脑干损伤部位不同的患者,其预后差异有统计学意义.结论 在脑干损伤急性期,头颅MRI检查对腩干损伤的检出率较头颅CT高,同时对脑干病灶显示得更加清楚.依据MRI表现可以对脑干损伤进行分类,并为脑干损伤患者提供影像学诊断及预后评价依据.     

Imaging of congenital cranial dysinnervation disorders: What radiologist wants to know?

We aim to review the imaging features of congenital cranial dysinnervation disorders. Characteristic imaging findings can define subtypes of these disorders through assessment of cranial nerves, extraocular muscles, orbital, and brain abnormalities. Duane retraction syndrome shows absent or hypoplasic 6th cranial nerve and preserved extraocular muscles (EOM). Mobius syndrome shows absent 7th and 6th cranial nerves, absence of facial colliculus, flattening of the dorsal aspect of the pons, hypoplasia of the pons and medulla, and flattening of the 4th ventricular floor. Congenital fibrosis of the extraocular muscles reveals unilateral or bilateral hypoplasia or aplasia of the 3rd cranial nerve, atrophy of superior rectus and levator palpebrae superioris muscles, and atrophy of the brainstem and cerebellar hemispheres. Horizontal gaze palsy and progressive scoliosis show characteristic split pons sign, butterfly medulla, absent facial colliculi, and spinal scoliosis. HOXA1 Mutations show a bilateral absence of 6th cranial nerves with the underdeveloped inner ear. Pontine Cap Tegmental Dysplasia shows ventral pontine hypoplasia, dorsal tegmental projection into the 4th ventricle, and variable cranial nerve deficits.     

Brain stem type neuro-Behçet's syndrome

Summary Brain stem type neuro-Behçet's syndrome was studied with enhanced CT and MRI during the acute and chronic stage of the illness. During the acute stage, brain CT revealed a low density lesion in the brain stem extending from the lower pons up to the midbrain ventrolaterally with marginal enhancement effect. T2-weighted image showed a high signal intensity lesion in the brain stem which mainly involved the basis ponti, tegmentum, tectum and cerebral peduncle. During the chronic stage, the lesion became low in signal intensity with T2-weighted image and reduced in its size without enhancement in brain CT. The prolonged relaxation time of the lesions was gradually normalized with steroid treatment. Sequential brain CT with enhancement and MRI study with T1- and T2-weighted images were useful to detect the lesions and to evaluate the activity in the neuro-Behçet's syndrome.     

小脑幕切迹下疝的CT诊断

目的 确定小脑幕切迹下疝的CT表现。方法 回顾性分析经临床证实的68例小脑幕切迹下疝的CT表现。结果 CT显示因脑组织移位及中脑本身受压移位导致单侧或双侧鞍上池改变60例、脚间池改变56例、环池改变52例、四叠体池改变50例。多数为前疝和半环疝。均有脑干的移位、旋转及变形改变，可伴有四脑室的变窄、闭塞及幕上占位病变的一系列改变。结论 参考原发病变的占位程度，脑干与脑干周围脑池两CT改变均存在并结合起来分析，可作出正确诊断。     

鼻咽癌放疗后放射性脑病的MRI诊断

作者观察了８４例鼻咽癌放疗后放射性脑病（ＲＥＰ）。其ＭＲＩ表现：病变主要位于双侧颞叶、脑干及小脑，Ｔ１ＷＩ病灶以低信号为（８１．３％），Ｔ２ＷＩ均为高信号，占位征象占２７．４％，萎缩征象占９．５％。还讨论了ＲＥＰ与脑梗塞、脑干胶质瘤及脑转移瘤的鉴别诊断。并提出了ＲＥＰ的ＭＲＩ分型，可分为颞叶型、脑干型、小脑型和混合型。作者还强调了ＭＲＩ显示ＲＥＰ，特别是显示脑干、小脑和颞叶底部的病灶，为ＣＴ及其他     

Neuroradiological findings in the carbohydrate-deficient glycoprotein syndrome

The carbohydrate-deficient glycoprotein syndrome is a newly recognised genetic disorder characterised by mental retardation, liver disfunction during infancy, cerebellar ataxia and atrophy, polyneuropathy, growth retardation, stroke-like episodes, and the appearance of carbohydrate-deficient fractions of multiple glycoproteins in the serum. The neuroradiological findings have been known as features of olivopontocerebellar atrophy. However, whether the abnormalities in the cerebellum and brain stem progress after birth is not known. We have carried out serial CT and MRI on three Japanese patients with this syndrome at different ages. A small cerebellum, with peculiar enlargement of the cisterna magna, and a small brain stem are present in infancy and atrophy of the anterior vermis and from before backwards in the cerebellar hemispheres seem to progress throughout early childhood.     

Congenital varicella syndrome: cranial MRI in a long-term survivor

Congenital varicella syndrome is a rare disorder which follows maternal infection in the first or early second trimester. The syndrome comprises a number of malformations including microcephaly, cortical destruction and limb hypoplasia. We describe a case where there has been long-term survival following second trimester maternal infection. The clinical findings, including the characteristic lower limb hypoplasia, are documented, as are the appearances on cranial MRI indicating an encephaloclastic porencephaly. Received: 23 June 1998 Accepted: 3 July 1998     

获得性免疫缺陷综合征的脑部MRI表现

本文分析１０例获得性免疫缺陷综合（ＡＩＤＳ）的脑部ＭＲＩ表现。将脑部异常分成５种类型：脑萎缩（８例）、白质病变（６例）、灰质病变（１例）、肿块（５例）和出血（２例）。最常见类型是前２者。ＭＲＩ诊断ＡＩＤＳ的单一致病病原体十分困难，但结合脑萎缩与对称性脑室周围或弥漫性白质病变可提示人类免疫缺陷病毒（ＨＩＶ）脑炎。     

Developmental changes in the posterior cranial fossa of children studied by CT

We reviewed 181 brain CT examinations, with no abnormal findings, to determine normative data for the posterior cranial fossa (PF) in children. The volume of the PF and the supratentorial cranial cavity (SC) was assessed by summing consecutive CT cross-sectional areas. Linear measurements of the PF structures-cerebellum, vermis, brain stem and fourth ventricle-were also performed. The PF grows rapidly during the first 3 years of life and thereafter a smaller increase in size is observed. All the PF structures showed a positive correlation with the PF volume. The PF volume increased in parallel with that of the SC and the PF/SC volume ratio remained relatively constant during childhood. The establishment of normative data for the volume of the PF and its contents may be of value in the CT study of diseases associated with morphological alterations in the PF.     

Leigh syndrome in a 3-year-old boy with unusual brain MR imaging and pathologic findings

We report unusual MR serial imaging and electron microscopy findings in a 3-year-old boy who had Leigh syndrome with cytochrome-c oxidase (cox) deficiency. The MR imaging findings included periventricular white matter involvement, posteroanterior progression, and extension through the corpus callosum and internal capsule; however, no basal ganglia or brain stem abnormality was found, which was suggestive of leukodystrophy. The most noteworthy findings were the cystic foci with contrast enhancement in the affected white matter.     

Whistling face syndrome: MR imaging findings in the brain

Whistling face syndrome or cranio-carpotarsal dysplasia is a very rare disorder that consists of a characteristics facies and digital abnormalities. Magnetic resonance imaging investigation of the brain in this syndrome has not been reported previously. This communication describes the brain malformations in an infant with the syndrome, which covered delayed myelination, thickened and infolded cortices (cortical dysplasia), dysplastic corpus callosum, and agenesis of the inferior vermis.