Diffusion-weighted magnetic resonance imaging (MRI) in acute brain stem infarction]

Diffusion-weighted magnetic resonance imaging (DWI) provides one of the earliest demonstrations of ischemic lesions. However, some lesions may be missed in the acute stage due to technical limitation of DWI. We therefore conducted the study to clarify the sensitivity of DWI to acute brain stem infarctions. Twenty-eight patients with the final diagnosis of brain stem infarction(midbrain 2, pons 9, medulla oblongata 17) who had been examined by DWI within 24 hours of onset were retrospectively analyzed for how sensitively the initial DWI demonstrated the final ischemic lesion. Only obvious(distinguishable with DWI alone without referring clinical symptoms and other informations) hyperintensity on DWI was regarded to show an ischemic lesion. Sixteen(57.1%) out of 28 patients had brain stem infarctions demonstrated by initial DWI. In the remaining 12 cases, no obvious ischemic lesion was evident on initial DWI. Subsequent MRI studies obtained 127 hours, on average after the onset showed infarction in the medulla oblongata in 11 cases and in the pons in one case. Negative findings of DWI in the acute stage does not exclude possibility of the brain stem infarction, in particulary medulla oblongata infarction.     

重型颅脑损伤长期意识障碍患者MRI表现与预后的关系

目的 探讨重型颅脑损伤长期意识障碍患者磁共振成像(MRI)表现与预后的关系.方法 收集珠江医院神经外科自2003年1月至2008年8月收治的66例重型颅脑损伤后意识障碍超过2周的患者的头部MRI资料,统计MRI横断位扫描T2WI像中脑干、丘脑、基底前脑、胼胝体、大脑皮层下及大脑皮层等区域的异常信号表现,以颅脑损伤后6个月患者是否清醒分为清醒组与非清醒组,运用Logistic回归分析计算患者头部MRI中的损伤灶位置与清醒与否的OR值,明确对预后有影响的独立危险因素.结果 头颅MRI中脑干腹侧及背侧、双侧基底前脑、双侧丘脑、胼胝体、双侧大脑额叶区域损伤和未损伤患者在清醒组与非清醒组间比较差异有统计学意义(P<0.05).Logistic回归分析显示脑干背侧损伤、丘脑右侧损伤、胼胝体损伤是影响预后的独立危险因素.结论 MRI表现可较客观、准确地反映脑损伤程度和预测患者的预后,脑干中上段背侧、胼胝体、丘脑有损伤灶的患者预示着难以清醒.     

Neuropsychological consequences of two patterns of brain damage shown by MRI in survivors of severe head injury.

Two subgroups of patients were identified from 48 patients with traumatic head injury who had MRI during the acute stage: (a) those with severe diffuse injury--six patients with lesions in both the corpus callosum and the brain stem; (b) those with severe focal injury--16 patients with extensive frontotemporal lesions. Most patients with diffuse injury were in a coma on admission to hospital, whereas most patients with focal injury were out of coma. Duration of post-traumatic amnesia was prolonged in both groups. Patients were followed up at six months after injury, when a battery of neuropsychological tests was given. Patients with both diffuse and focal patterns of injury were impaired by comparison with controls on a range of measures, including tests of memory and attention. The findings contrast with the view that diffuse injury is of much greater importance than focal injury in determining outcome after head injury.     

CT中脑背侧脑池出血对原发性脑干损伤的早期诊断价值

目的 分析颅脑外伤急诊CT中脑背侧脑池出血的表现,探讨其对临床原发性脑干损伤的早期诊断价值.方法 回顾性分析52例颅脑外伤患者临床表现及影像学资料,并依据GCS评分分为轻、中、重及特重型.所有患者均在伤后48 h内接受CT检查,CT采用常规程序扫描.MRI检查则根据病情变化在伤后1周内完成,采用自旋回波T1WI、T2WI序列.结果 所有病例的CT表现均与MRI的T1WI、T2WI序列行比较研究,其中39例颅脑损伤患者的急诊CT有中脑背侧环池或四叠体池出血表现,合并弥漫性脑肿胀19例,脑实质出血灶单发或多发点状出血灶11例,直径小于2 cm;37例MRI检查存在不同程度的脑干组织损伤表现.结论 重型和特重型颅脑外伤(GCS<9分)伤后早期CT的中脑背侧脑池出血表现高度提示原发性脑干损伤可能,对提高原发性脑干损伤早期诊断水平具有重要的参考价值.     

脑干梗塞急性期弥散MRI的探讨

目的:弥散加权MRI(DW1)因能够在早期、快速、敏感地反映出脑部缺血性病变而成为脑梗塞患者急性期诊断不可缺少的重要的检查方法,但是对于某些部位的某些小的病灶在急性期DW1有时亦不能查出。本研究以脑干梗塞的患者为对象,对急性期DW1的敏感度进一步探讨。方法:以发病24小时以内施行DWI检查的28例患者作为对象;DWI是在1.5Tesl的MR装置下,采用断层回波成像的,与此同时,还进行了T2加权MRI及水抑制成像FLAIR(fluidattenuated inversion recovery)的检查,最终梗塞灶根据平均127小时后的以上所述的MRI检查中的所见及临床症状来综合判断的,只把明确的高信号区域判断为病灶。结果:最终梗塞灶为中脑2例,桥脑9例,延髓17例。通过第一次DWI,检查出病灶的16例(敏感度57.1％),没有明确检查出病灶的12例,其中在这12例患者中有11例是在以后的MRI检查中发现为延髓病变,有1例确认为桥脑病变。从发病开始到施行DWI检查为止,时间越短,病变越不容易查出。结论:应该注意在急性期的DWI中即使没有明确的病灶,也不能否认脑干梗塞,特别是延髓梗塞。     

Magnetic resonance imaging in clinically isolated lesions of the brain stem.

Twenty-seven patients with an isolated brain stem syndrome, thought to be due to demyelination, were examined by magnetic resonance imaging (MRI). A brain stem lesion was identified in 25, and clinically silent lesions outside the brain stem were demonstrated in 20. MRI was more sensitive than evoked potentials in detecting brain stem and other lesions. The scan findings were compared with those in 23 patients with multiple sclerosis, who had chronic brain stem dysfunction, with particular reference to the distribution of abnormalities and the MRI characteristics of the lesions. The relaxation times, T1 and T2, of the lesions were measured by MRI. These values were seen to fall in serial studies of acute lesions, but remained unchanged in the chronic lesions. MRI may therefore allow the age of lesions to be assessed.     

Magnetic resonance imaging after 'diffuse' nonmissile head injury. A neurobehavioral study

The diagnosis of diffuse brain injury is considered when computed tomography provides no evidence of an intracranial mass lesion in acute nonmissile head injury. Magnetic resonance imaging (MRI) of a young woman who had sustained severe diffuse brain injury five years earlier disclosed multifocal lesions involving the frontal, temporal, parietal, and occipital lobes. We report the results of serial neurobehavioral assessment for clinical correlation with the brain lesions visualized by MRI. Pending confirmation of our findings in a series of patients studied by MRI during the acute and chronic stages of recovery from head injury, we postulate that the presence and type of neurobehavioral sequelae of diffuse brain injury are related to the intrahemispheric loci of predominantly white matter lesions and degeneration.     

弥漫性轴索损伤在重型脑损伤中的意义

在15例闭合性脑损伤尸检中,病理诊断弥漫性轴索损伤(DAI)5例。根据病理研究结果和文献报道,分析了530例急性脑外伤病人脑CT表现,发现DAI61例。其CT表现为大脑皮髓质交界处、基底节内囊区域、胼胝体、脑干或小脑有一个或多个直径≤2cm的出血灶,脑室内出血及急性弥漫性脑肿胀。本文把DAI分为高颅压型和非高颅压型,后者又分的脑干损伤型和局灶性损伤型。这种分型对指导治疗和判断预后均有重要意义。DAI预后较差,是目前脑外伤病人死亡率高的重要原因之一。     

Computed cranial tomography, magnetic resonance imaging and brain echo imaging in Japanese B encephalitis]

We reported computed cranial tomography (CCT), magnetic resonance imaging (MRI) and brain echo imaging in Japanese B encephalitis. The result were assessed in comparison with the clinical feature of the disease. CCT of the three patients showed low density in thalamus and basal ganglia. In two, the lesions were detected in the acute phase, and changed to high density in the chronic phase. Their prognosis was poor, psychomotor delay and paresis persisted. Among the previously reported sixteen patients of Japanese B encephalitis in Japan, the four developed thalamic lesions on CCT and the prognosis was poor in all patients. Brain echo detected the lesions in the acute phase before CCT visualised them clearly. MRI demonstrated thalamic hemosiderin deposits and calcification. These findings were compatible with the pathological findings, or past hemorrhage and organization. The distribution of the lesion were closely connected with the prognosis.     

Clinico-radiological spectrum in enterovirus 71 infection involving the central nervous system in children

Enterovirus 71 infection causes hand, foot and mouth disease in children, and can produce diverse neurologic complications. Epidemics occurring in Korea between 2009 and 2012 resulted in the death of some patients. The present study aimed to clarify the correlation between clinical features and MRI findings in patients presenting with acute neurologic manifestations related to enterovirus 71 infection. Based on their clinical features, the patients were classified into four clinical groups: (1) brainstem encephalitis (n = 17), characterized by myoclonus, tremor, ataxia, and autonomic dysregulation such as pulmonary hemorrhage; (2) aseptic meningitis (n = 2); (3) encephalitis (n = 2), characterized by decreased consciousness, seizure, and fever without myoclonus, tremor, ataxia, and autonomic dysregulation; and (4) acute flaccid paralysis (n = 1). Thirteen of the 17 patients with brainstem encephalitis showed characteristic lesions in the dorsal brainstem and bilateral cerebellar dentate nuclei on brain MRI, whereas three had no abnormality. One of the two patients with meningitis had a small lesion in the left dorsal pons. Two patients with encephalitis had no apparent MRI abnormality. One patient with acute flaccid paralysis of the right leg had contrast-enhancement of the bilateral ventral nerve roots at the lumbar spine level on MRI. Five of 13 patients with lesions in the bilateral dentate nuclei of the cerebellum exhibited no cerebellar symptoms, while two with no cerebellar lesions developed ataxia. Although most patients presenting with neurologic manifestations of enterovirus 71 infection had characteristic clinical features together with typical MRI findings, the clinical features were not necessarily consistent with MRI findings.     

Acute post-traumatic intraventricular hemorrhage analysis of 25 patients with emphasis on final outcome

A series of 25 patients suffering acute post-traumatic intraventricular hemorrhage (IVH) after closed head injury is reviewed. Post-traumatic IVH was associated with other brain lesion in most cases; intracerebral lesions with contusion, subdural hematoma, and epidural hematoma coexisted with post-traumatic IVH in ten, three, and one instance, respectively. In six cases, no CT abnormality other than IVH was noted. The final outcome in this series is poor, only 10 (40%) patients made a functional survival. Four different groups of IVH were proposed according to the CT scan findings: deep nuclei hemorrhage, brain stem injury, white matter hemorrhage and isolated IVH. The group of isolated IVH usually got a good outcome. The abnormal motor response, abnormal pupil reaction and impaired oculocephalic response were reliable parameters for poor prognosis.     

Magnetic resonance imaging and brain-stem auditory evoked potentials in neuro-Behcet's disease

We studied central nervous system lesions in patients with neuro-Behcet's disease using magnetic resonance imaging (MRI) of the brain and recording of brain-stem auditory evoked potentials (BAEPs). MRI revealed abnormal findings in seven of eight patients. MRI studies demonstrated extensive regions with high intensity signal in the brain stem and/or basal ganglia on T2-weighted images obtained during the acute stage of the disease in three patients. One of these patients had a strongly gadolinum-enhanced round lesion in the lower pons. In four of the other five patients with chronic disease, brain-stem atrophy was observed on T1-weighted images. Atrophic changes were more severe in the brain stem than in the cerebellum. Abnormal BAEPs were observed in three patients and consisted of prolongation of interpeak latency of waves III-V and defects of wave III or V. Abnormal BAEPs were recorded in patients with severe inflammatory changes or progression of atrophic changes in the brain stem. Our findings show that MRI and BAEPs are useful in detecting the presence and assessing the degree of neurological involvement in patients with neuro-Behcet's disease.     

Incidence and prognostic value of spindles in post-traumatic coma

One hundred and thirty-three EEGs were analysed from 80 comatose patients with signs of brain stem impairment due to head/brain injury. Seventy EEGs were taken in acute coma on day 1 or 2 after brain injury. Sixty-three EEGs were recorded in prolonged coma 3-12 days after brain injury. Brain stem involvement was divided by neurological signs and by CT scan into secondary lesions due to supratentorial mass displacement and primary lesions due do direct violence to the brain stem. Different EEG patterns were observed, but spindle activity was of special interest. Spindles were classified as typical (easily recognizable, well organized, 12-14 c/sec activity) or atypical (hardly recognizable, distorted form, 6-11 c/sec activity). Furthermore, asymmetries of spindles were noted. The spindles and their alterations were related to different stages of outcome. Spindles were seen in 91% of the EEGs in acute coma and in 30% in prolonged coma. In acute coma due to secondary brain stem involvement a good outcome was heralded by the occurrence of typical symmetrical spindles combined with early stages of secondary brain stem impairment at neurological examination. In cases of primary brain stem involvement typical spindles also suggested a good prognosis despite the observation of serious clinical signs (decerebrate posturing). The percentage of spindle activity decreased, and distortion and asymmetry of spindles increased with the worsening of outcome. Severe intracerebral lesions (confirmed by clinical and CT scan examinations) led to distortion, asymmetry and finally disappearance of spindles. In prolonged coma spindle activity was markedly reduced regardless of the final outcome. When spindles were present atypical and asymmetric forms significantly increased in patients with bad outcome. There were no significant differences in spindle activity in the different outcome categories, if primary and secondary brain stem lesions were compared.     

Topodiagnostic investigations on the sympathoexcitatory brain stem pathway using a new method of three dimensional brain stem mapping

OBJECTIVES: To study the incompletely understood sympathoexcitatory pathway through the human brain stem, using a new method of three dimensional brain stem mapping on the basis of digitally postprocessed magnetic resonance imaging (MRI). METHODS: 258 consecutive patients presenting with acute signs of brain stem ischaemia underwent biplane T2 and EPI diffusion weighted MRI, with slice orientation parallel and perpendicular to a transversal slice selection of the stereotactic anatomical atlas of Schaltenbrand and Wahren, 1977. The individual slices were digitally normalised and projected onto the appropriate slices of the anatomical atlas. For correlation analysis lesions were imported into a three dimensional model of the human brain stem. RESULTS: 31 of the 258 patients had Horner's syndrome caused by acute brain stem ischaemia. Only four of the patients with Horner's syndrome had pontine infarctions, 12 had pontomedullary lesions, and 15 had medullary lesions. Correlation analysis showed significantly affected voxels in the dorsolateral medulla but not in the pons. A statistical comparison with infarct topology in patients with medullary lesions but without Horner's syndrome indicated that involvement of the medial and ventral part of affected voxels located in the ventrolateral medullary tegmentum was specific for Horner's syndrome. CONCLUSIONS: Based on this first in vivo topodiagnostic study, the central sympathoexcitatory pathway probably descends through the dorsal pons before converging on specific generators in the ventrolateral medullary tegmentum at a level below the IX and X nerve exits.     

Acute cerebellar ataxia in children

Acute cerebellar ataxia is a benign syndrome usually occurring after an acute febrile disease. In a few cases neuroradiological investigations reveal cerebellar alterations. Clinical and neuroradiological involvement of the brain stem has rarely been reported in the literature. We present five cases of acute cerebellar ataxia. In two cases the cerebellar symptomatology was associated with neurological signs of brain stem involvement. CT scans did not show any pathologic findings in three patients. MRI disclosed cerebellar or brain stem alterations in all the patients. Clinical and neuroradiological findings allow differentiation of this pathologic entity from other demyelinating or dysmyelinating diseases. The value of MRI in detection and localization of the lesions and in following their evolution is emphasized. Received: 4 December 1996 Revised: 20 May 1997     

MR imaging of acquired fetal brain disorders

Introduction Acquired fetal brain disorders represent the third indication of fetal brain MRI, after ventricular dilatation and malformations of the central nervous system.Discussion MRI is an adequate imaging technique for evaluating fetal brain damage. Fetal brain response to brain injury may be acute, chronic or a combination of acute and chronic. An acute response is not as common in the fetal brain as in the postnatal period. A chronic response or the combination of chronic and acute response are the most common responses of the fetal brain to injury, whatever its origin. MRI also provides the natural history of acquired fetal brain lesions with regard to the stage of development.     

Brain stem lesions after head injury

There is little knowledge on the morphology of the brain stem in survivors of head injury, as CT fails to shown brain stem lesions, and neuropathological data is only available from autopsies. As magnetic resonance imaging (MRI) sheds new light on morphological lesions of the brain, the authors investigated 100 patients with a severe head injury. MRI was performed in a prospective study within the first seven days after head injury while the patients were still in coma and on ventilation. Relating the location of the lesions as depicted by MRI with the initial CT scan and outcome, death appeared to be closely linked to the phenomenon of bilateral pontine lesions. The extent of supratentorial lesions had no bearing on survival at all in the absence of brain stem lesions. Altogether the brain stem was affected in 52%. Obviously the occurrence of bilateral upper pontine lesions is of highest predictive value for a fatal outcome. Severe destruction of supratentorial white matter as demonstrated by MRI is not related to increased mortality, as long as the brain stem is spared.     

Central nervous system effects in acute thallium poisoning

We report the central nervous system manifestations, neuropsychological studies and brain magnetic resonance image (MRI) findings of two patients with acute thallium intoxication. Neurologically the patients suffered from confusion, disorientation, and hallucination in the acute stage, followed by anxiety, depression, lack of attention, and memory impairment, in addition to peripheral neuropathy. Neuropsychological tests revealed an impairment of memory function, including reversed digital span, memory registration, memory recall, memory recognition, similarity, proverb reasoning, and verbal fluency. High concentrations of thallium were found in the urine, blood, and drinking water of these two patients. Brain MRI showed lesions in the corpus striatum in one patient. During the follow-up periods, the clinical manifestations and neuropsychological studies showed a slowly progressive improvement, and a follow-up brain MRI 1.5 months later demonstrated a resolution of the lesions. We conclude that thallium intoxication might induce encephalopathy, and brain MRI studies demonstrated the acute-stage brain lesions in a severe intoxicated patient. In addition, neuropsychological tests also confirmed memory deficits, although the brain lesions in the corpus striatum might resolve.     

Conventional MRI and MR spectroscopy in nonclassical mitochondrial disease: report of three patients with mitochondrial DNA deletion

Objects The objectives were to present magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) findings in three patients with deletion on mitochondrial DNA (mtDNA) and nonclassical mitochondrial disorders (NCMD), correlating these findings with the percentage of deleted mtDNA.Results Our study confirms the high prevalence of white matter (WM), basal ganglia, and posterior fossa lesions in NCMD, ranging from mild to severe involvement. The subcortical WM, caudate, thalamus, globus pallidus, and dorsal brain stem were more frequently affected. A lactate peak was the most frequent finding at the MRS. We found a correlation between the percentage of mtDNA deletion and degree of MRS abnormalities.Conclusions Our findings showed that MRS is a useful investigational tool in patients with NCMD. Supplementary studies are necessary to elucidate the correlation of quantitative mtDNA deletion and neuroimaging phenotype.     

Serum levels of matrix metalloproteinase-9 and its tissue inhibitor (TIMP-1) in acute disseminated encephalomyelitis

In multiple sclerosis, there have been many reports on matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs). However, MMPs and TIMPs have not been reported in acute disseminated encephalomyelitis (ADEM). We determined the relationship between the serum concentrations of MMP-9 and TIMP-1 and activity of lesions on MRI in 14 patients with ADEM to investigate the roles of MMP-9 and TIMP-1 in the pathogenesis of ADEM. Serum MMP-9 and TIMP-1 levels, measured by ELISA and gadolinium-enhanced (Gd+) brain MRI, were analyzed. Serum MMP-9 and TIMP-1 levels at the acute stage were higher than controls, and the serum MMP-9 levels at the acute stage were higher than those at the convalescent stage in ADEM. In seven patients with Gd+ lesions on brain MRI, serum MMP-9 levels and the MMP-9/TIMP-1 ratio at the acute stage were higher than those at the convalescent stage, and serum TIMP1 levels at the acute stage were lower than those at the convalescent stage. In seven patients without Gd+ lesions on brain MRI, serum TIMP-1 levels at the acute stage were higher than those at the convalescent stage. We speculated that MMP-9 is related to lesion formation at the early stage in ADEM and that TIMP-1 is induced to modulate MMP-9 activity. These findings suggest that MMP-9 and TIMP-1 secondarily play some roles in the inflammatory cascade of ADEM.