Serial MRI findings in patients with CNS cryptococcosis]

We reported the serial magnetic resonance imaging (MRI) findings of two patients with central nervous system (CNS) cryptococcal infection without AIDS. The diagnosis of CNS cryptococcosis was made by visualizing the fungi in the CSF with the India ink test, detecting cryptococcal antigens, and culturing the fungus. Both patients had dilated perivascular Virchow-Robin (V-R) spaces, which were defined as small rounded lesions greater less than 3mm diameter that were hyperintense on T2-weighted images. They were present in the basal ganglia, brainstem and cerebral white matter. Case 1 had bilateral parietal arachnoid cyst which was thought to represent a focal collection of organisms and mucoid material within subarachnoid space. Abnormal optochiasmatic arachnoid enhancement detected in case 2, who had complete loss of vision. With disease progression perivascular V-R increased in size, resulting in the developing cryptococomas which were defined as rounded lesions greater than 3mm diameter, and were hyperintense on T2-weighted images in the basal ganglia, cerebellum and cerebral white matter. In follow-up MRI of those patients, radiological progression was seen despite appropriate treatment and falling CSF cryptococcal antigens. In conclusion, this spectrum of MRI appearances in CNS cryptococcosis reflects the pathological mechanism of invasion by the fungus, and may be relatively specific for cryptococcosis.     

Clinical, electroencephalographic and cerebral computerized-tomographic findings in patients with ischemic stroke

The clinical findings, EEG and CT examinations of the brain were compared at three time intervals in patients with ischaemic stroke. No evident correlation was found between the intensity of clinical signs, the intensity of EEG changes and the size of the ischaemic focus in the CT. It was observed that with increasing time interval after the onset of the disease the clinical state and EEG changes improved while the CT image was not changed or even became worse. In the observations a greater tendency clinical for improvement was found in the group of cases of lesions in the left parietal lobe than in those with lesions in the right parietal lobe. Another observation was that patients with ischaemic focus developing in brain with evidence of atrophy in CT had a much lower tendency for clinical improvement than those without brain atrophy.     

Linear cortical cystic lesions: Characteristic MR findings in MELAS patients

BackgroundMitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) is a progressive neurodegenerative disorder with stroke-like lesions. The common MRI findings are gyral swelling and high signal intensity on T2WI/FLAIR images crossing the vascular territories. We have observed a linear cystic lesion and a laminar necrosis in the affected cortices of MELAS patients. Herein, we evaluated these cortical MRI findings in each subtype of mitochondrial disease.Patients and methodsWe retrospectively reviewed the MRI findings of 71 consecutive patients with clinically and genetically confirmed mitochondrial diseases. The cortical cystic lesions and laminar necrotic lesions were evaluated on T1, T2, and FLAIR images in each subtype of mitochondrial disease, as were their clinical and other imaging characteristics.ResultsThe cortical cystic lesion was observed in 21 of the 71 patients (29.6%) with mitochondrial diseases. Laminar necrosis was detected in only three patients (4.2%). MELAS was the most frequent subtype with cortical cystic lesions, accounting for 81.0%, and all showed the linear pattern except for one patient whose pattern was beaded-like.ConclusionA cortical linear cystic lesion was a common MRI finding in our series of patients with mitochondrial disease, especially in those with MELAS, but laminar necrosis was not. These findings can help differentiate MELAS from infarction.     

Serial brain imaging analysis of stroke-like episodes in MELAS

We report 2 patients of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) and consider the pathophysiology of stroke-like lesions, using magnetic resonance imaging (MRI), diffusion-weighted imaging (DWI) on MRI, perfusion imaging on MRI, and 1H magnetic resonance spectroscopy (1H-MRS). In Patient 1, T2-weighted imaging (T2-WI) on MRI at onset and even at 44 days after onset of the stroke-like episode showed high intensity in left parietal, temporal, and occipital lobe lesions. In the temporal lobe lesion, the apparent diffusion coefficient (ADC) at 44 days after onset was higher (average: 1.219x10(-3)mm2/s) than that in a normal region (average: 0.796x10(-3)mm2/s). (1)H-MRS of the left parietal lobe lesion at the same day showed a decrease in N-acetylaspartate/(creatine+phosphocreatine) (NAA/Cr) (0.43) and a peak in lactate. 1H-MRS of the contralateral side at the same day showed NAA/Cr (1.57) and no peak in lactate. Thereafter, ADC gradually decreased and NAA/Cr gradually increased, and the peak in lactate disappeared in the lesion. In Patient 2, T2-WI at onset showed high intensity in bilateral occipital lobe lesions. In the left occipital lobe lesion, ADC at the same day was higher (1.082x10(-3)mm2/s) than that in a normal region (average: 0.841x10(-3)mm2/s). (1)H-MRS of the left occipital lobe lesion at the same day showed a decrease of NAA (3.0mM) and a peak in lactate (13.1mM) (measured by LCModel). In 1H-MRS of the normal left parietooccipital lobe at 4 months before onset, NAA was 7.6mM and there was no peak in lactate (0mM). Perfusion imaging at onset showed high intensity in bilateral occipital lobes, which indicated hyperperfusion in stroke-like lesions. Thereafter, ADC gradually decreased and the peak in lactate partially decreased, and the low concentration of NAA persisted (regardless of the partial recovery) in the lesion. These results suggest that the stroke-like episodes is related to vasogenic edema, hyperperfusion, and neuronal damage. Acute oxidative phosphorylation defect may have a crucial role in the pathophysiology of stroke-like episodes.     

Early electroencephalographic findings in patients with anoxic encephalopathy after cardiopulmonary arrest and successful resusitation.

This study investigated whether or not early electroencephalographic (EEG) findings and brain computed tomographic (CT) features reflect the prognosis of comatose patients for 48 h after cardiopulmonary resuscitation (CPR). EEGs and brain CT scans were collected from 21 patients within 72 h after CPR. The EEG findings were classified according to the five Hockaday grades. The Glasgow outcome scale (GOS) applied 3 months after CPR was used for prognosis. Of the nine patients with grade 1 and 2 EEGs, eight had a good outcome (five recovered satisfactorily and three remained moderately disabled). Of the eight patients with grade 4 and 5 EEGs, seven had a poor outcome (three died and four remained in a persistent vegetative state). On the other hand, there was no correlation between early CT features and prognosis except for two severe cases, one whose gray/white matter interface had disappeared and the other with relatively increased density of the thalami, brain stem and cerebellum. These findings suggest that EEG is more useful than CT scan as a diagnostic tool for anoxic encephalopathy after CPR.     

Serial computed tomographic and electroencephalographic studies in Creutzfeldt-Jakob disease

The serial changes in computed tomography (CT) as correlated with the clinical and electroencephalographic findings were evaluated in 3 patients with Creutzfeldt-Jakob disease. The disease was subsequently confirmed histologically in 2. CT revealed that brain atrophy began in an early clinical stage and was prominent even before the state of akinetic mutism. Periodic synchronous discharges (PSDs) were observed either before or simultaneous with the observation of myoclonus. With progressive brain atrophy, the frequency of PSDs and the degree of myoclonus both decreased and disappeared 8 to 15 months after the onset of disease.     

老年脑卒中患者癫痫发作的临床特点、脑电图表现及其危险因素分析

目的探讨老年人群脑卒中后癫痫(PSE)发作的临床特点、脑电图表现及其危险因素,为癫痫的早期预防提供依据。方法选取儋州市人民医院收治的脑卒中患者1485例,最终纳入患者992例,分析患者的临床特点及脑电图表现。根据脑卒中后癫痫发作情况,将其分为癫痫发作组87例和无癫痫发作组905例。应用单因素及多因素Logistic回归分析PSE的危险因素。结果 PSE的发生率为8.77%,其中早发型癫痫占55.17%,迟发型癫痫占44.83%。PSE发作的脑电图呈弥散性异常占26.44%,局限性异常占48.28%。单因素及多因素Logistic回归分析显示,高同型半胱氨酸血症、病灶部位、病灶范围、电解质紊乱、日常生活能力及NIHSS评分≥25分是PSE发作的独立危险因素,其OR(95%CI)值分别为2.063(1.146~3.125)、6.285(5.168~9.047)、4.725(3.684~6.835)、3.029(2.016~4.532)、2.538(1.568~3.562)和3.163(2.085~4.726)。结论老年人群脑卒中后癫痫发作的发生率较高,影响癫痫发作的危险因素较多,对存在危险因素的患者应高度警惕其癫痫的发生。