脑卒中后华勒变性一例分析

目的 探讨脑卒中后华勒变性的发生过程和机制.方法 报道1例临床高度怀疑脑卒中而影像学发现双侧、对称性小脑中脚异常信号的病例的诊治过程,结合临床和解剖分析双侧小脑中脚异常信号的产生机制.结果 单侧脑桥的旁正中梗死病灶可致数月后出现双侧脑桥小脑束华勒变性,表现为头颅磁共振成像上双侧小脑中脚对称、均一的长T1、长T2、高Flair、高DWI、低ADC等信号.结论 脑卒中后华勒变性是疾病的发展过程,充分认识这一现象可以避免临床误诊误治.     

Bilateral wallerian degeneration of the middle cerebellar peduncles due to unilateral pontine infarction

We report the case of a patient with bilateral and symmetrical T2 hyperintensities of the middle cerebellar peduncles. She had a history of left pontine infarction 8 months before. This was attributed to bilateral Wallerian degeneration. MR Spectroscopy showed decreased N-acetyl aspartate/Creatine (NAA/Cr) ratio in the cerebellar peduncles as well as in the whole cerebellum. We hypothesize that this could reflect neuronal degeneration following a stroke.     

沃勒变性在中枢神经系统的MRI表现

目的 回顾沃勒变性及继发跨神经元退变的病理学改变,分析其在中枢神经系统的MRI表现。方法 根据沃勒变性的影像学标准,选择1995～1999年经MRI确诊的沃勒变性患者20例,年龄16～70岁,平均52岁。其中脑梗死11例,脑出血4例,创伤手术后2例,肿瘤术后1例,脑膜瘤1例,脑白质病1例。回顾性分析其MRI表现。结果 20例患者原发病灶均位于幕上,16例于原发病灶同侧出现条带样连续或不连续长T_1或等T_1、长T_2改变,位于皮质脊髓束通路。FLAIR及DWI扫描均显示高信号病灶。3例仅见原发灶同侧大脑脚萎缩,但未见异常信号。7例见局限性胼胝体萎缩,T_2加权像信号略显增高。2例患者出现交叉性小脑萎缩,示皮质脑桥小脑通路退变。结论 对中枢神经系统的沃勒变性和继发跨神经元退变描述的是分子水平的病理学变化,因变性是沿着已知的神经通路的、且存在特定信号改变,故MRI可在活体中对其进行观察和诊断。     

A case of late adult-onset dentatorubral-pallidoluysian atrophy mimicking central pontine myelinolysis

We report the case of a 52-year-old man with late-onset dentatorubral-pallidoluysian atrophy (DRPLA). MRI findings of late-onset DRPLA usually showed the involvement of cerebral white matter lesions with high intensity on T2-weighted images (WI), in addition to brainstem, globus pallidus, and thalamus. But our patient did not present with abnormal manifestation of white matter lesions of the cerebrum. In addition, the appearance of pontine base was remarkably similar to central pontine myelinolysis (CPM). There is no reported case of DRPLA mimicking CPM in the literature, while there is one previous report of CPM with cerebellar ataxia without pyramidal tract involvement, and CPM may exhibit cerebellar ataxia. Although there is differentiation between CPM and DRPLA by the presence of the atrophy of brainstem and cerebellum, the characteristic MRI findings of pontine base may make it difficult to differentiate CPM with cerebellar ataxia from DRPLA with inconspicuous leukoencephalopathy. In such a situation, we should return to the clinical history and background of a patient, and, if necessary, DNA analysis should be performed for a definite diagnosis.     

不同部位脑梗死后华勒变性3例报道及文献复习

目的探讨不同部位脑梗死后锥体束华勒变性的发生过程和机制。方法报道3例不同部位脑梗死后华勒变性患者的临床资料,根据临床和影像学特点并结合文献对其进行分析。结果颈内动脉或大脑中动脉供血区急性脑梗死后可出现锥体束和胼胝体华勒变性,表现为同侧锥体束（内囊、大脑脚）与胼胝体出现T2和DWI高信号,ADC低信号,并且DWI和ADC信号改变比T2更明显;而单侧脑桥基底部梗死可于数月后出现双侧脑桥小脑束华勒变性,表现为双侧小脑中脚T2和DWI高信号,ADC等信号。结论脑梗死后华勒变性是疾病的发展过程,应充分认识这一现象,避免临床误诊为新发脑梗死。     

Multiple system atrophy mimicry in MRI: Watch out for paraneoplastic rhombencephalitis

The hot cross bun (HCB) sign describes cruciform-shaped T2-weighted hyperintensities of pontocerebellar fibers within the pons and is a typical, but not specific imaging hallmark of the cerebellar variant of multiple system atrophy (MSA-C). We report a case of a 51-year-old woman who was first diagnosed with MSA-C based on progressive cerebellar ataxia, the HCB sign and T2-weighted hyperintensities in middle cerebellar peduncles on MRI. However, further diagnostic work-up revealed positive anti-amphiphysin antibodies in blood and cerebrospinal fluid and subsequently breast cancer. This report of a paraneoplastic rhombencephalitis which initially mimicked MSA-C imaging features stresses the importance of considering immune-mediated rhombencephalitis as differential diagnosis in cases of progressive cerebellar ataxia and the HCB sign on T2-weighted MRI, especially in the absence of pontocerebellar atrophy.     

Internuclear ophthalmoplegia and cerebellar ataxia: report of one case.

Deep hemispheric or brainstem small infarcts can lead to atypical lacunar syndromes. Unilateral internuclear ophthalmoplegia (INO) and cerebellar ataxia has not been reported previously. A 57-year-old hypertensive female presented with bilateral appendicular and left truncal cerebellar ataxia and right INO. Cranial MRI showed a right paramedian infarct of lacunar size located in the tegmentum of caudal mesencephalon. At this level the involvement of medial longitudinal fascicle (MLF) led to right INO and the lesion of brachium conjunctivum caused the bilateral cerebellar ataxia. Ipsilateral involvement of both cerebellofugal fibers, before and after decussation, was responsible for bilateral cerebellar ataxia.     

Prominent cerebellar symptoms with unusual magnetic resonance imaging findings in acquired hepatocerebral degeneration

BACKGROUND: Cerebellar lesions revealed by abnormal signals on magnetic resonance images are extremely rare in acquired hepatocerebral degeneration (AHCD). OBJECTIVE: To report a case of AHCD with prominent cerebellar findings both clinically and radiologically. DESIGN AND SETTING: Case report and tertiary-care hospital. PATIENT: A 46-year-old man complained of progressive speech difficulties of 5 months' duration. Two years earlier, he had been diagnosed as having cirrhosis of the liver caused by alcoholism and hepatitis B virus infection. RESULTS: The patient had progressive ataxic dysarthria and limb and gait ataxia as manifestations of AHCD. Magnetic resonance imaging of the brain revealed distinctive symmetrical T2 high-signal intensities in the bilateral cerebellar hemispheres and brachium pontis, which were consistent with his neurologic deficits. Simultaneously, high T1 signals in the bilateral pallidum and ventral midbrain were noted, which are typical manifestations of AHCD. Follow-up magnetic resonance imaging 3 months later showed the same cerebellar signs and abnormal signals. CONCLUSIONS: The cerebellar cortex and middle cerebellar peduncle are considered highly vulnerable structures to metabolic insults in liver disease. Findings from our patient suggest that dominant cerebellar deficits with compatible T2 high-signal lesions are another type of clinical manifestation in AHCD.     

MRI and SPECT findings in a case of metronidazole-induced reversible acute cerebellar ataxia]

A 69-year-old man was referred to our department because of acute onset nausea, vomiting, dysphagia, dysarthria and gait disturbance. He had a 50-day-history of amebic dysentery and had been treated with 1,500 mg metronidazole per day. Neurological examination revealed dysphagia, ataxic speech, ataxia of the left extremities and the trunk, and hyperactive deep tendon reflexes in all extremities. Sensory impairment of all modalities was apparent in a glove and stocking pattern, with mild paresthesia. Brain MRI showed T2 high signal lesions in the bilateral cerebellar dentate nuclei, more markedly on the left. On brain SPECT, obvious low blood perfusion was observed in the left cerebellar hemisphere. These findings well explained the ataxia of the left limbs. One month after discontinuing metronidazole, the cerebellar ataxia, dysphagia and MRI abnormalities completely cleared. Therefore, central nervous system damage induced by metronidazole is considered reversible. In spite of the presence of the MRI lesion in the right dentate nucleus, the patient had no ataxia of the right extremities and there was no hypoperfusion in the right cerebellar hemisphere. Thus, metronidazole does not appear to have a direct neurotoxic effect on the central nervous system. On the other hand, nerve conduction studies showed axonal polyneuropathy, which was not improved one month after cessation of the drug; thus metronidazole seems to exert more damage on peripheral nerves.     

Two cases of acute disseminated encephalomyelitis with lesions in the thalamus or basal ganglia on MRI]

Lesions in the thalamus or basal ganglia have rarely been reported in acute disseminated encephalomyelitis (ADEM). We experienced 2 cases of ADEM, in which MRI showed lesions in the thalamus or basal ganglia. Case 1, a 4-year-old boy, had gait disturbance, hyperesthesia and hyperreflexia. MRI (T2 weighted image) showed multiple high intensity areas in the right frontal lobe, bilateral parietal lobes and bilateral thalami. Case 2, a 4-year-old girl, complained of gait disturbance following a febrile episode, and displayed hyperreflexia. Several days later, she had visual disturbance of the left eye. MRI (T2 weighted image) revealed multiple high intensity areas in the dentate nucleus of left cerebellum, left occipital lobe, bilateral caudate nuclei, and the anterior part of bilateral lenticular nuclei. In both cases, CT could not demonstrate these lesions. Both of them were treated with corticosteroid and recovered rapidly. They had no recurrence. MRI is useful in diagnosis and follow-up of ADEM and may reveal lesions other than cerebral or cerebellar white matters.     

Cerebrotendinous xanthomatosis--a case of brain MRI abnormality and osteoporosis]

A 37-year-old male with cerebrotendinous xanthomatosis showed brain abnormal MRI findings and osteoporosis. His parents had no similar symptoms. He had mental retardation since childhood. Swelling of Achilles tendons was noticed at age 28, and gait disturbance appeared at age 34. Physical examination revealed bilateral cataracts and swelling of Achilles tendons. Neurologically, he showed mental retardation, cerebellar ataxia and spastic tetraparesis. Cerebrotendinous xanthomatosis was diagnosed by marked elevations of serum cholestanol level (24.3 micrograms/ml) and cholestanol/cholesterol ratio (1.81%) as well as characteristic clinical manifestations. On brain MRI study, T2-weighted sequence showed bilateral focal lesions with high intensity signal in the globus pallidus and cerebellar white matter adjacent to the dentate nucleus, and T1-weighted sequence showed low to iso-intensity signal in the same regions. These findings suggested demyelination rather than xanthoma or lipid infiltration. Radiological examination showed mild osteoporosis of lumbar bone. However, serum levels of vitamin D3 and calcitonin were within normal range, and renal function was normal. Osteoporosis in this patient possibly resulted from disuse bone atrophy for several years. The combination therapy of oral administration of chenodeoxycholic acid and HMG-CoA reductase inhibitor (pravastatin), and LDL apheresis slightly improved EEG abnormality and gait disturbance, but not brain MRI abnormality.     

Adult onset Langerhans cell histiocytosis with progressive cerebellar ataxia and spastic paraparesis]

A 44-year-old woman with progressive cerebellar ataxia and spastic paraparesis was referred to our hospital. Brain MRI showed bilateral high signals in superior, middle, and inferior cerebellar peduncles on the T2 weighted images. After 3 years, her symptoms progressively worsened in spite of various therapies including whole brain irradiation and high dose oral prednisone. No evidence of diabetes insipidus was noted. In MRI, brainstem lesions expanded to both hemispheres of the cerebellum without enhancement by contrast medium. We confirmed diagnosis of LCH by skin biopsy of intractable truncal rash which emerged after neurological symptoms.     

Intrafamilial variability in fragile X-associated tremor/ataxia syndrome.

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a progressive adult-onset tremor/ataxia syndrome caused by premutations in the FMR1 gene. In cranial MRI, the most characteristic findings are bilateral T2 hyperintense lesions within the middle cerebellar peduncles. Here we present a sibpair of two affected brothers presenting with very different symptoms (typical FXTAS versus essential tremor-like), disease progression, and MRI findings, illustrating broad intrafamilial variability of FXTAS. Also, their family history suggests further evidence of possible manifestation of FXTAS in women.     

MRI findings of brain-stem tuberculoma in a case of tuberculous meningitis]

A 54-year-old woman developed headache and slight fever. When she consulted a physician, she could not move either of her eyes to the right. Cranial CT scan revealed no significant findings. Lumbar puncture was performed and CSF examination showed the cell count of 10,304/mm3, glucose level of 10 mg/dl, and total protein value of 270 mg/dl. Her symptoms and laboratory findings suggested meningitis and she was admitted to our hospital. Neurological examination revealed bilateral dilated pupils with sluggish light reflex, right gaze palsy, and hypesthesia of the left side of her face. A diagnosis of tuberculous meningitis was established by a positive test for acid-fast bacillus in CSF, and anti-tuberculous therapy was started at once. One month after the onset of symptoms, her main complaints were double vision and cerebellar ataxia. Both CT and MRI revealed a right brain-stem lesion. Pre-contrast CT could not clearly visualize the lesion but with contrast medium a homogeneously-enhanced circular lesion was shown. MRI on T2WI demonstrated the right brain-stem lesion to have a central bright core with hypointense periphery, which in turn was surrounded by hyperintensity. The lesion appeared isointense with cerebral white matter and the "central bright core" area was demonstrated to be slightly hypointense on T1WI. On post-contrast T1WI (with Gd-DTPA), the lesion showed strong homogeneous enhancement. The CT and MRI findings indicated a brain-stem tuberculoma, which was regarded as the cause of the ocular movement paralysis and cerebellar ataxia. As the clinical symptoms gradually resolved with anti-tuberculous treatment, the MRI appearance of the lesion also improved.(ABSTRACT TRUNCATED AT 250 WORDS)     

吸食海洛因致海绵状白质脑病的CT及MRI诊断

目的评价海洛因中毒所致的海绵状白质脑病的CT、MRI表现及诊断价值.方法搜集6例海洛因海绵状白质脑病的CT及MRI资料,全部患者均进行MRI检查,检查序列包括T1WI、T2WI、FLAIR序列,其中2例同时行颅脑CT扫描. 结果全部患者MRI显示对称性双侧小脑半球、大脑半球后部、内囊后肢、胼胝体压部、脑干等皮质下白质为主的多发性大片状长T1、长T2信号,加强后病灶无强化;2例行头颅CT检查显示两大脑半球皮质下白质、基底节及两侧小脑呈对称性广泛低密度灶,无占位效应.结论海洛因中毒所致的海绵状白质脑病具有特征性的MRI表现,MRI对本病的诊断具有重要价值.     

中脑梗死继发双侧肥大性橄榄核变性

肥大性橄榄核变性(HOD)是一种罕见且特殊的跨突触变性,发病率低,易被忽略。主要继发于脑干和小脑的破坏性病变。临床典型表现为腭肌震颤和共济失调,影像学特征为T2WI高信号。现总结分析1例继发于中脑梗死的典型双侧HOD病例,以期提高临床工作中对该病的认识。     

Cerebellar peduncular myelinolysis in a patient receiving hemodialysis

Here, we report the observation of extrapontine lesions, in addition to the pontine lesions previously documented in a diagnosed case of hemodialysis-associated osmotic demyelination syndrome due to end-stage renal disease. The patient exhibited lesions on bilateral middle cerebellar peduncles, and had been receiving regular hemodialysis as treatment for end-stage renal disease. He presented with progressive gait disturbance and postural instability. Accompanying symptoms included peduncular hallucinations and mild cognitive dysfunction. Brain MRI revealed high signal intensity in the area of bilateral cerebellar peduncles on the diffusion and T2-weighted images, with a decreased signal intensity noted on the ADC map. The ataxic form of osmotic myelinolysis syndrome is quite rare. The involvement of the cerebellar peduncles in extrapontine myelinolysis in a patient with end stage renal disease has not, to our knowledge, been previously reported. Here, we describe the MRI findings and clinical features associated with this unique case, and include a review of the relevant literature.     

A case of Turner syndrome complicated with brain infarction]

A 21 year-old female college student with a history of Turner syndrome at age 9, and 6-year growth hormone replacement therapy noticed weakness of right extremities when she got up on March 26, 2001. On admission, she showed right hemiparesis (4+/5) and hypesthesia on the right of body. The hemiparesis progressed (3-/5) in spite of antithrombotic therapy. Brain MRI revealed a high intensity lesion with a diameter of 1.5 cm in the posterior limb of the left internal capsule and putamen on DWI and T2WI. MR angiography and TC-CFI revealed no stenosis in her left middle cerebral artery, but > 50% stenosis in the horizontal portion (M1) of her right middle cerebral artery. Branch lesions were presumed to exist in the left M1. Non-atherosclerotic angiopathy, coagulopathy, and other conventional risk factors of brain infarction were not found. Pathogenesis of Turner syndrome might have played a role in the development of brain infarction in this patient.     

A Case of Cerebral Erdheim-Chester Disease With Progressive Cerebellar Syndrome

Erdheim-Chester disease (ECD) is a rare non-Langerhans form of histiocytosis. Cerebellar involvement is rare in this syndrome. We report a 37-year-old woman with slowly progressive cerebellar ataxia, dysmetria of limbs, nystagmus, and dysarthria, bilateral painful axillary masses, and generalized arthralgia. Brain MRI revealed cerebellar atrophy with focal lesions in the pons, middle cerebellar peduncle, and the cerebellum. She underwent incisional biopsy of her axillary masses which showed findings consistent with ECD. An MRI of her lower extremities revealed lesions in the diaphyses, metaphyses, and epiphyses of the proximal tibia and distal femur bilaterally. This is a rare case of cerebral ECD with progressive cerebellar syndrome associated with cerebellar atrophy.