Identification of hemodynamically compromised regions by means of cerebral blood volume mapping utilizing computed tomography perfusion imaging.

The aim of the study was to evaluate the potential role of computed tomography perfusion (CTP) imaging in identifying hemodynamically compromised regions in patients with occlusive cerebrovascular disease. Twelve patients diagnosed with either occlusion or severe stenosis of the internal carotid artery or the M1 portion of the middle cerebral artery underwent CTP imaging. The data was analyzed by an automated ROI-determining software. Patients were classified into two subgroups: an asymptomatic group consisting of three patients in whom perfusion pressure distal to the site of occlusion/stenosis (PPdis) could be maintained in spite of the arterial occlusion/stenosis, and a symptomatic group consisting of nine patients in whom PPdis could not be maintained enough to avoid watershed infarction. Four CTP-related parameters were independently compared between the two groups. Significant differences were determined using a two-sample t-test. When statistically significant differences were identified, cut-off points were calculated using ROC curves. Analysis revealed statistically significant differences between the asymptomatic and symptomatic subgroups only in the measure of relCBV (p=0.028). Higher relCBV values were observed in the symptomatic subgroup. ROC curve analysis revealed 1.059 to be the optimal relCBV cut-off value for distinguishing between the asymptomatic and symptomatic subgroups. The data revealed that, in patients whose PPdis is maintained, relCBV remains around 1.00. Conversely, in patients whose PPdis decreased, relCBV increased. From these findings, we conclude that elevation of relCBV as observed using CTP imaging accurately reflects the extent of compensatory vasodilatation involvement and can identify hemodynamically compromised regions.

Hemodynamic stress distribution reflects ischemic clinical symptoms of patients with moyamoya disease.

OBJECTIVE: Currently, the probability of diagnosing asymptomatic moyamoya disease is increasing. In this study, we consider a less invasive method for predicting future ischemic symptoms in patients with moyamoya disease. METHODS: We reviewed cerebral blood flow (CBF)-related data obtained by xenon CT imaging (XeCT) in six patients with ischemic-type or asymptomatic moyamoya disease. The data were obtained as volume data using a 320-row CT, and applied to the automated region-of-interest-determining software (3DSRT) and converted to standardized images. Eight CBF-related parameters, including CBF value, cerebrovascular reserve capacity (CVRC), and hemodynamic distribution (hdSD), were compared between asymptomatic hemispheres and ischemic symptomatic hemispheres. A significant difference was determined by a two-sample t test. A difference with p<0.05 was considered significant. When statistically significant differences between parameters of asymptomatic hemispheres and ischemic symptomatic hemispheres were identified, cut-off points were calculated with receiver operating characteristic (ROC) curves. Change in the parameters before and after bypass surgery was also assessed. RESULTS: Of the eight CBF-related parameters evaluated, statistically significant differences between the asymptomatic hemispheres and ischemic hemispheres were observed in the CBF value of the MCA region (CBF-MCA), both at rest and after acetazolamide loading, and in the hdSD, also both at rest and after acetazolamide loading. Of the four statistically significant parameters, ROC analysis revealed that the hdSD at rest and CBF-MCA after acetazolamide loading were the most sensitive and specific parameters (threshold 1.2, sensitivity 1, specificity 1 for hdSD at rest, and threshold 26.44mL/100g/min, sensitivity 1, specificity 1 for CBF-MCA after acetazolamide loading). From the CBF data obtained both before and after surgery from the three patients who had undergone direct bypass surgeries, the hdSD was higher than the threshold of 1.2 before surgery but decreased to lower than the threshold of 1.2 after surgery. Ischemic symptoms also resolved after surgery. CONCLUSIONS: The data showed that hdSD at rest and CBF-MCA after acetazolamide loading reflects ischemic symptoms of patients with moyamoya disease. Thus, these parameters could be used as ischemic symptom markers for following patients with moyamoya disease. hdSD at rest is important because it is less invasive and can be performed without acetazolamide loading.

Usefulness of Preoperative Surgical Simulation with Three-Dimensional Fusion Images for Resection of Cerebral Cavernous Malformations Near Broca's Area.

Treating subcortical brain lesions in or near eloquent areas is challenging not only because lesions must be resected while preserving brain tissue involved in essential functions, but also because lesions often cannot be easily identified from the surface of the brain. Here, we report 2 cases of cerebral cavernous malformations near Broca's area. In both cases, lesions were surgically removed by utilizing three-dimensional fusion images created using preoperative magnetic resonance imaging and computed tomography data. Excisions were completed without any worsening of speech function, and the use of presurgical simulations was found to be useful in the design and execution of the actual operations. The technique described in this report serves as a useful tool in simulating surgical strategies by using brain gyri and sulci as surgical landmarks. Furthermore, in contrast to other intraoperative techniques, this method can aid in shortening the duration of surgery and can help limit damage to eloquent areas of the brain.

Neurenteric cysts found on the outer membrane of a subdural haematoma.

We report on a patient initially diagnosed with a chronic subdural haematoma that was resistant to treatment. After the second burr hole craniostomy within a half month failed to resolve the subdural haematoma (SDH), we performed a craniotomy to identify the point of bleeding. Macroscopic evaluation showed that most of the outer membrane of the SDH was transparent; however, further examination revealed the presence of multiple white regions. Pathologic examination showed that the white regions were fluid filled and surrounded by columnar ciliated epithelial cells. These lesions were pathologically diagnosed as neurenteric cysts. To our knowledge, this is the first report on a patient with neurenteric cysts found on the outer membrane of a CSDH. We agree that a craniotomy is a treatment of last resort for recurrent CSDHs; however, sometimes this procedure can be very useful for identifying underlying causes of obstinate SDHs as well as for their treatment.

Severe parkinsonism following endoscopic third ventriculostomy for non-communicating hydrocephalus--case report.

A 23-year-old male with non-communicating hydrocephalus caused by intraventricular hemorrhage from an arteriovenous malformation was treated by endoscopic third ventriculostomy (ETV) after repeated ventricular cerebrospinal fluid drainage and removal of ventriculoperitoneal shunt due to infection. Postoperatively, the patient developed robust rigidity and akinesia with mutism, suggesting secondary parkinsonism. These symptoms showed marked improvement after administration of levodopa, and were not aggravated after discontinuation. The pathophysiology of this case might involve dysfunction of the dopaminergic system caused by repeated compression and release of the paraventricular white matter. Careful perioperative management not leading to excessive dilation of the the ventricles should be considered for ETV for non-communicating hydrocephalus to avoid this unexpected complication.

[A case of carotid stenting via the transbrachial approach in the bovine arch].

We report our experience in carotid stenting via the transbrachial approach in patients with anomalous origin of the left common carotid artery, the so-called bovine arch, in which both the right common carotid artery and the left common carotid artery arise from the brachiocephalic artery. Via percutaneous access to the right brachial artery, a 6Fr Shuttle sheath is advanced into the aortic arch to cannulate the left common carotid artery. A Guardwire distal-protection balloon is positioned within the left internal carotid artery distal to the stenosis. The lesion is dilated, followed by satisfactory deployment and dilation of a 6Fr Precise stent. Carotid stenting via the brachial artery in bovine arch appears feasible as an alternative to standard femoral access.