Utility of fractional anisotropy imaging analyzed by statistical parametric mapping for detecting minute brain lesions in chronic-stage patients who had mild or moderate traumatic brain injury.

Diffusion tensor imaging (DTI) has recently evolved as valuable technique to investigate diffuse axonal injury (DAI). This study examined whether fractional anisotropy (FA) images analyzed by statistical parametric mapping (FA-SPM images) are superior to T(2)*-weighted gradient recalled echo (T2*GRE) images or fluid-attenuated inversion recovery (FLAIR) images for detecting minute lesions in traumatic brain injury (TBI) patients. DTI was performed in 25 patients with cognitive impairments in the chronic stage after mild or moderate TBI. The FA maps obtained from the DTI were individually compared with those from age-matched healthy control subjects using voxel-based analysis and FA-SPM images (p < 0.001). Abnormal low-intensity areas on T2*GRE images (T2* lesions) were found in 10 patients (40.0%), abnormal high-intensity areas on FLAIR images in 4 patients (16.0%), and areas with significantly decreased FA on FA-SPM image in 16 patients (64.0%). Nine of 10 patients with T2* lesions had FA-SPM lesions. FA-SPM lesions topographically included most T2* lesions in the white matter and the deep brain structures, but did not include T2* lesions in the cortex/near-cortex or lesions containing substantial hemosiderin regardless of location. All 4 patients with abnormal areas on FLAIR images had FA-SPM lesions. FA-SPM imaging is useful for detecting minute lesions because of DAI in the white matter and the deep brain structures, which may not be visualized on T2*GRE or FLAIR images, and may allow the detection of minute brain lesions in patients with post-traumatic cognitive impairment.

Simultaneous integrated boost technique by helical tomotherapy for the treatment of glioblastoma multiforme with 11C-methionine PET: report of three cases.

We performed hypofractionated high-dose irradiation of a patient's residual glioblastoma multiforme using a simultaneous integrated boost (SIB) technique with helical tomotherapy system (HT) planning. The gross tumor volume (GTV)-1 was defined as the area of intensive (11)C-methionine (MET) uptake and GTV-2 was defined as the area of moderate MET uptake. The planning target volume (PTV)-1 encompassed GTV-1 plus a 5 mm margin, and PTV-2 encompassed GTV-2 plus a 2 mm margin. SIB with HT was performed in eight fractions, planning the dose for GTV-1 at 68 Gy (biologically effective dose: BED = 126 Gy), PTV-1 at 56 Gy (BED = 95 Gy), and PTV-2 at 40 Gy (BED = 60 Gy). In each of the target areas, the uptake value on (11)C-methionine positron emission tomography (MET-PET) was considerably decreased following SIB, although no remarkable changes were demonstrated on magnetic resonance imaging (MRI). These cases demonstrate that SIB with HT planning using MET-PET offers excellent target coverage and uniformity. In addition, SIB with HT planning using MET-PET is organ sparing and MET-PET has great efficacy for monitoring treatment response after SIB. To more clearly define the impact of SIB with HT planning using MET-PET, further investigations are required.

Statistical image analysis of cerebral glucose metabolism in patients with cognitive impairment following diffuse traumatic brain injury.

The aim of this study was to explore the regional cerebral glucose metabolism (rCM) in patients with chronic stage traumatic brain injury (TBI) compared with normal controls. We also investigated the relationship between regional cerebral glucose metabolism and cognitive function. We performed 2-[(18)F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) study using statistical parametric mapping (SPM) analysis in 36 diffuse axonal injury (DAI) patients (mean age +/- SD, 36.3 +/- 9.8 years). At 6 months or more after head injury, all patients underwent FDG-PET study and neuropsychological batteries to assess cognitive function. Thirty healthy, gender-matched control subjects who were comparable in age were also studied. Between the TBI patients and normal controls, group comparisons showed regional metabolic decreases in the bilateral frontal lobes, temporal lobes, thalamus, as well as the right cerebellum in the TBI group. Only full-scale Intelligence Quotient (IQ) (mean +/- SD, 78.5 +/- 11.9) correlated positively with rCM in the right cingulate gyrus and the bilateral medial frontal gyrus. In other examinations, the correlation was not provided. DAI may induce functional disconnection and decreased neuronal activity, and finally lead to diffuse glucose hypometabolism. Low full-scale IQ scores may be related to significantly different underlying cognitive impairment. In supporting cognitive function following TBI, which showed diffuse cerebral metabolic reduction compared with normal controls, medial prefrontal cortex and anterior cingulate cortex may be an important component.

Tensor magnetic resonance imaging in a case of mild traumatic brain injury with lowered verbal intelligence quotient.

We report the case of a 31-year-old man who had mild traumatic brain injury as a result of an accident at the age of 24 years. Seven years after the trauma, at the age of 31 years, he had a lower verbal intelligence quotient than performance intelligence quotient by the Wechsler Adult Intelligence Scale - Revised, and frontal lobe dysfunction, for example, difficulty in maintaining or changing the set as revealed by the Wisconsin Card Sorting Test Keio Version. Conventional brain magnetic resonance imaging had not shown any abnormalities. Abnormal brain areas were detected on magnetic resonance diffusion tensor imaging. On tractography, some fibres from the corpus callosum towards the frontal cortex were noted to be lacking in the left hemisphere compared with the right. The tractography results may explain the patient's lowered verbal intelligence quotient and focal left frontal lobe dysfunction. Diffusion tensor imaging is therefore helpful in detecting lesions in mild traumatic brain injury with diffuse axonal injury.

Correlation between diffusion-tensor magnetic resonance imaging and motor-evoked potential in chronic severe diffuse axonal injury.

We conducted a study to evaluate the degree of corticospinal tract (CST) dysfunction associated with diffuse axonal injury (DAI) through analyses of both diffusion-tensor magnetic resonance imaging (DTMRI) and motor-evoked potential (MEP). Using DTMRI and MEP with transcranial magnetic stimulation, we evaluated 138 instances of CST in 52 patients with severe chronic DAI and compared them with the findings in 17 normal volunteers. We determined values of fractional anisotropy (FA) on FA maps obtained with DTMRI of six regions of interest (ROIs) in the CST, consisting of the semioval center, coronal radiation, posterior limb of internal capsule, midbrain, pons and medulla oblongata. The lowest value of %FA for each of the six ROIs in each CST was defined as the minimum %FA, and the lowest magnetic stimulation strength that produced MEP was defined as the minimum threshold for MEP. The mean minimum %FA for CSTs in which MEP could not be obtained even with maximum magnetic stimulation (the MEP- group) was significantly lower than that of CSTs in which MEP could be obtained (the MEP+ group). ROIs with the lowest %FA value were the midbrain in the MEP+ group and the medulla oblongata in the MEP- group. In the MEP+ group, a serial decrease in the minimum %FA value significantly correlated with a serial increase in minimum threshold for MEP. These results show that in patients with chronic DAI, physiological motor dysfunction as revealed by MEP correlates significantly with morphological damage to the CST as detected by DTMRI. This strongly suggests that DTMRI can be a valuable tool for evaluating aberrant motor function and for estimating its severity in DAI.

Thrombosed unruptured cerebral aneurysm causing brain infarction followed by subarachnoid hemorrhage--case report--.

A 71-year-old man presented with right hemiparesis and aphasia due to cerebral infarction in the frontal lobe. Computed tomography (CT) revealed a high-density mass, 12 mm in diameter, in the stem of the left sylvian fissure. Carotid angiography demonstrated occlusion of the left ascending frontal artery complex and retention of contrast medium at the bifurcation of the left middle cerebral artery (MCA). The diagnosis was cerebral infarction caused by occlusion of the ascending frontal artery complex resulting from thrombosed left MCA aneurysm. The patient was managed conservatively and his neurological symptoms gradually improved. One month later, he lapsed into a coma. CT revealed subarachnoid hemorrhage. Carotid angiography showed a large left MCA aneurysm with branch occlusion of the left ascending frontal artery complex. A left frontotemporal craniotomy was performed. The MCA aneurysm was opened and the intramural thrombi removed, and finally neck clipping was performed. The patient made a good postoperative recovery.

Cognitive impairment after traumatic brain injury: a functional magnetic resonance imaging study using the Stroop task.

The anterior cingulate cortex (ACC) plays a key role in cognition, motor function, and emotion processing. However, little is known about how traumatic brain injury (TBI) affects the ACC system. Our purpose was to compare, by functional magnetic resonance imaging (fMRI) studies, the patterns of cortical activation in patients with cognitive impairment after TBI and those of normal subjects. Cortical activation maps of 11 right-handed healthy control subjects and five TBI patients with cognitive impairment were recorded in response to a Stroop task during a block-designed fMRI experiment. Statistical parametric mapping (SPM99) was used for individual subjects and group analysis. In TBI patients and controls, cortical activation, found in similar regions of the frontal, occipital, and parietal lobes, resembled patterns of activation documented in previous neuroimaging studies of the Stroop task in healthy controls. However, the TBI patients showed a relative decrease in ACC activity compared with the controls. Cognitive impairment in TBI patients seems to be associated with alterations in functional cerebral activity, especially less activation of the ACC. These changes are probably the result of destruction of neural networks after diffuse axonal injury and may reflect cortical disinhibition attributable to disconnection or compensation for an inefficient cognitive process.

Hemangioblastomatosis of the central nervous system without von Hippel-Lindau disease: a case report.

We report a very rare case of hemangioblastomatosis in a patient without von Hippel-Lindau disease (VHL). A 50-year-old woman had a history of surgical procedures for total removal of a cerebellar hemangioblastoma (HB). Twenty-one years after the last operation, she developed communicating hydrocephalus; computed tomographic (CT) scans of the brain showed no recurrence of HB in the posterior fossa. Subsequently, she underwent placement of a ventriculo-peritoneal shunt. One year later, she was readmitted because of progressive numbness and pain in the left lower limb. Magnetic resonance imaging (MRI) showed multiple Gd-enhancing tumors around the brain stem, in the cerebellum, and in the cervical and thoracolumbar regions of the spine. She underwent surgical removal of the tumors in the cerebellum and spinal cord. Although the extirpated tissues were histopathologically verified HB with less than 1% MIB-1 labeling index, surgery was followed by external beam radiation therapy with doses of 40 Gy to the whole brain, 10 Gy to the posterior fossa and 30 Gy to the whole spine. However, she subsequently developed quadriparesis and became bedridden.

[The clinical utility of MR diffusion tensor imaging and spatially normalized PET to evaluate traumatic brain injury patients with memory and cognitive impairments].

We detected and compared abnormal brain areas using both MR diffusion tensor imaging (DTI) and easy Z score imaging system (eZIS) of FDG-PET for traumatic brain injury patients with memory and cognitive impairments. Twenty normal subjects and eighteen diffuse axonal injury patients with memory and cognitive impairments were studied with DTI and eZIS of 18F-FDG-PET. DTI contained fractional anisotorophy (FA) analysis and the tractography for the corpus callosum. After PET imaging was performed, statistical analysis using eZIS was undergone with followed processing steps, including smoothing, normalization and z transformation with respect to normal database. Z score map was superimposed on 3D MRI brain. Group analysis was performed using SPM. In diffuse axonal injury patients, the decline of FA was observed around the corpus callosum in comparison with normal subjects and the reduction of glucose metabolism was shown in the cingulated association. These results suggest that the reduction of metabolism within the cingulated cortex indicated deprived neuronal activation caused by the impaired neuronal connectivity that was revealed with DTI. Furthermore, the metabolic abnormalities within the cingulated cortex may be responsible for memory and cognitive impairments. DTI and spatially normalized PET have a role in neuroimaging interpretation for patients with memory and cognition impairments because its 3D better visualization allows objective and systematic investigation.

A non-infantile case of desmoplastic infantile astrocytoma.

CASE REPORT: We describe a very rare non-infantile case of desmoplastic infantile astrocytoma (DIA). A 9-year-old boy presented with motor weakness and sensory disturbance in his right upper and lower limbs. CT and MRI showed a contrast-enhanced large cystic tumor in the left sensorimotor area. We successfully resected the entire tumor. Its histopathological features were typical of DIA. OUTCOME: The patient's neurological symptoms improved postoperatively. Neither radiotherapy nor chemotherapy was used postoperatively. The patient developed normally and had been doing well for 12 months after surgery without tumor recurrence.

Fluorescence-guided resection of glioblastoma multiforme by using high-dose fluorescein sodium. Technical note.

The authors have recently performed a fluorescence-guided tumor resection procedure by using high-dose fluorescein sodium without any special surgical microscopes for the intraoperative visualization of glioblastoma multiforme (GBM), and they report on the actual procedure and clinicopathological findings. Thirty-two patients with GBMs underwent tumor resection during which this fluorescence-guided procedure was used. Fluorescein sodium (20 mg/kg) was intravenously injected after dural opening at the craniotomy site. The tumor was stained almost homogeneously yellow and the color was intense enough to be readily perceived for resection. The center of the solid lesion was stained a deep yellow and surrounded by a transition zone that was faintly stained. The colored lesion was clearly distinguishable from the unstained zone outside the GBM, particularly in the white matter. Both the deeply and faintly stained regions included endothelial proliferation and dense tumor cells. In the unstained region, less dense tumor cells were consistently revealed; however, no endothelial proliferation could be seen. Gross-total resection (GTR) was successful in 84.4% of the patients who received an injection of fluorescein sodium, which accounted for 100% of those in whom all the visible yellow color (both the deeply and faintly stained regions) was judged to have been resected during operation. Gross-total resection was performed in 100% of the patients who underwent the fluorescence-guided procedure and assigned to Stage I, a GBM stage in which, as a therapeutic policy, the tumor should be resected as radically as possible. The GTR rates in patients who received fluorescein sodium were significantly higher than those in patients who did not (73 patients with GBMs who underwent tumor resection without the fluorescence-guided procedure). Although the extent of surgery was revealed to be one of the significant and independent prognostic factors for GBM, the fluorescein sodium-guided resection procedure was not a significant or independent prognostic factor in this series. This surgical procedure does not require any special surgical microscopic equipment and is simple, safe, useful, readily accomplished, and universally available for resection of GBMs. Its efficacy simplifies the surgical procedure of navigating the stained lesion from the unstained area to achieve GTR of GBMs, which can be demonstrated on magnetic resonance images.