Validation and evaluation of the volumetric measurement of cerebellopontine angle cistern as a prognostic factor of microvascular decompression for primary trigeminal neuralgia.

BACKGROUND: The aim of this study was to analyze the prognostic factors of trigeminal neuralgia (TN) after microvascular decompression (MVD), and to evaluate the volumetric parameters of the cerebellopontine angle (CPA) cistern as a pathogenic factor and imaging predictor. METHODS: This retrospective study included 70 patients with primary TN treated with pure MVD, followed up for at least 1 year and evaluated by high-resolution MR imaging. The volume of the CPA cistern was calculated bilaterally, and the "Cistern Deviation Index" was defined to represent degree of deviation of the CPA cistern. Clinical data and volumetric parameters were compared between patients with TN and age- and sex-matched controls without TN, and between the recurrent and non-recurrent patients. RESULTS: The transposition procedure had a better outcome than the interposition procedure (P < 0.001). There was a significant difference in the volume of CPA cistern between the affected and unaffected side (152.1 ± 50.1 vs. 179.9 ± 63.7 mm(3), P < 0.001) in patients with TN, while no significant difference between the right and left side (158.7 ± 44.6 vs. 163.1 ± 49.8 mm(3), P = 0.162) in controls. The Cistern Deviation Index was significantly larger in controls than in patients with TN (P = 0.048), and in the non-recurrent patients than in recurrent patients (P = 0.040). CONCLUSION: We demonstrated that the volumetric parameters of the CPA cistern are a marker for understanding the pathogenesis of TN and useful for predicting the recurrence after MVD. The Cistern Deviation Index might contribute to deciding the surgical approach.

Chronic encapsulated expanding hematoma in nonfunctioning pituitary adenoma.

The diagnosis and treatment of pituitary macroadenomas with entire hematoma fluid accumulation are problematic. Such lesions are often difficult to completely resect, and recurrence is not uncommon. We present five cases of pituitary macroadenomas entirely composed of hematoma fluid and investigated their histopathology to clarify the mechanism of the hematoma fluid accumulation. Five patients with pituitary adenoma and significant intra-tumor hematoma underwent transsphenoidal resection and were retrospectively reviewed for their clinical status, findings on magnetic resonance imaging (MRI), intraoperative findings, and histopathology. The specific surgical techniques used to address these cases were also reviewed. All patients were diagnosed with nonfunctioning pituitary adenomas by histopathological examination. MRI showed all tumors extended to the cavernous sinus. Histopathology showed tumor tissues were located between the thick granulation tissue and the pseudocapsule of the tumor. The thick granulation tissues were composed of collagenous layers, neovascular vessels, and necrotic red blood cells, indicating repeat hemorrhage from the granulation tissues. The boundary between adenoma and normal pituitary gland was identified during surgical removal in four patients and was not identified in the other patient who showed a recurrence 2 years later. Clinical and histopathological findings indicate hematoma fluid accumulation in the present cases is caused by repeat hemorrhage from the reactive granulation tissues and can be regarded as a chronic encapsulated expanding hematoma. In these cases, the boundary between adenoma and normal pituitary gland should be identified before puncturing the hematoma fluid to minimize the risk of tumor recurrence.

Cerebral ischemia model using mongolian gerbils-comparison between unilateral and bilateral carotid occlusion models.

We permanently occluded unilaterally and/or bilaterally the carotid arteries of anesthetized Mongolian gerbils (60-80 g) and compared the two models. In the former, stroke-positive animals were selected by calculating the stroke index score of the conscious animals. Selection was not made in the latter. We measured the rCBF of the cerebral cortex, hippocampus, and diencephalon using the (3)H-nicotine scintillation method; analyzed the EEG using the wave-form recognition method (Fujimori); measured ATP, PCr (phosphocreatine), lactate, and glucose content in the cerebral hemisphere using the Lowry method; and measured infarct size on HE-stained coronal sections. All parameter values were uniform in the gerbils of the unilateral model, whereas great variation was observed in the right and left cerebral cortex, hippocampus, and diencephalon in the bilateral occlusion model. Therefore, we have discarded the bilateral model and used the stroke-positive unilateral model only.By changing the length of time of the unilateral carotid occlusions and intervals, we found that two 10-min unilateral carotid occlusions with a 5-h interval between them achieved a threshold ischemic insult in gerbils, which produced uniform cortical focal infarctions that evolved in the maturing DSNN on the coronal surface sectioned at the chiasmatic level (Face A). This model showed a marked reduction in the occurrence of ischemic epilepsy and death.

A selective adenosine A2A receptor antagonist ameliorated hyperlocomotion in an animal model of lateral fluid percussion brain injury.

Increased concentration of extracellular adenosine after brain injury is supposed to be one of the causes of secondary brain damage. The purpose of the present study is to examine whether or not administration of adenosine A2A receptor antagonist may be efficacious in ameliorating neurological symptoms by blocking secondary brain damage through cascades initiated by adenosine A2a receptor.Mongolian gerbils were divided into four groups: the trauma-medication (T-M), trauma-saline (T-S), sham-medication (S-M), and sham-saline (S-S) groups. Trauma groups received lateral fluid percussion injury. Medication groups received i.p. injection of SCH58261 (selective adenosine A2A receptor antagonist) until the fifth post-injury day. Open-field locomotion test and grabbing test were conducted before and 1, 3, 5, 7, and 9 days after injury.The total distance of movement in the T-S group was significantly greater than in the other three groups at all time points. In the T-M group, administration of SCH58261 significantly blocked hyperlocomotion, which was observed in the T-S group. There was no significant difference in the total distance among the T-M, S-M, and S-S groups. In the grabbing test, grabbing time was significantly increased in the T-S group 3, 5, 7, and 9 days after the operation. SCH58261 also improved grabbing time in the T-M group.Adenosine A2A antagonist successfully suppressed the trauma-induced hyperlocomotion, presumably by blocking secondary brain damage.

PET molecular imaging to investigate higher brain dysfunction in patients with neurotrauma.

INTRODUCTION: Many neurotrauma patients suffer from higher brain dysfunction even when focal brain damage is not detected with MRI. We performed functional imaging with positron emission tomography (PET) to clarify the relationship between the functional deficit and symptoms of such patients. METHODS: Patients who complain of higher brain dysfunction without apparent morphological cortical damage were recruited. Thirteen patients underwent PET study to image glucose metabolism by (18)F-FDG, and central benzodiazepine receptor (cBZD-R) by (11)C-flumazenil, together with measurement of cognition. RESULTS: Diffuse axonal injury (DAI) patients have a significant decrease in glucose metabolism and cBZD-R distribution in the cingulated cortex than normal controls. Score of cognition test was variable among patients. The degree of decreased glucose metabolism and cBZD-R in the dominant hemisphere corresponded well to the severity of cognitive disturbance. Patients with a milder type of diffuse brain injury (i.e., cerebral concussion) also showed abnormal glucose metabolism and cBZD-R distribution when they suffered from cognitive deficit. CONCLUSION: PET molecular imaging was useful for depicting the cortical dysfunction of neurotrauma patients even when morphological change was not apparent. This method may be promising in clarifying the pathophysiology of higher brain dysfunction of patients with neurotrauma, but without morphological abnormality.

Combined extradural subtemporal and anterior transpetrosal approach to tumors located in the interpeduncular fossa and the upper clivus.

BACKGROUND: Central skull base lesions in the interpeduncular fossa and the upper clival regions can be challenging to access because of their location anterior to the brainstem. We have modified the anterior transpetrosal approach by combination with the extradural subtemporal route to increase the surgical corridor. METHODS: Thirty-seven patients underwent surgical treatment via the anterior transpetrosal approach from 2002 to 2012. The combined surgical approach was primarily applied when the tumors arose from the upper clival portion and extended to the interpeduncular fossa. The combined approach was used in seven of these patients, comprising four patients with petroclival meningiomas, one patient with sphenoclival meningiomas, one patient with trigeminal schwannoma, and one patient with an epidermoid cyst extending from the interpeduncular fossa to the prepontine cistern. RESULTS: The combined approach permitted excellent visualization of the interpeduncular fossa in addition to the upper clivus and the lateral aspect of the brain stem. Mobilization of the temporal lobe by the entire epidural dissection of the lateral wall of the cavernous sinus facilitates access via the subtemporal route. The transient symptom of the temporal lobe in the dominant site may be the only drawback for this combined approach, although it may disappear immediately after the surgery. CONCLUSION: The present approach combines Dolenc's approach and Kawase's approach, providing a wide exposure to lesions of the interpeduncular fossa and the clivus.

Circulatory characteristics of normovolemia and normotension therapy after subarachnoid hemorrhage, focusing on pulmonary edema.

BACKGROUND AND PURPOSE: Cardiopulmonary complications are common after subarachnoid hemorrhage (SAH), and include pulmonary edema (PE). The purpose of this study was to investigate circulatory characteristics of normovolemia and normotension therapy after SAH using pulse contour analysis, and to reveal the mechanisms of PE after SAH. METHODS: Pulse contour analysis was performed from day 3 until day 12 after the onset of SAH in 49 patients. RESULTS: Global end-diastolic volume index (GEDI) was normal, although net water balance was estimated to be negative and central venous pressure (CVP) was low in all patients. Seven patients (14 %) suffered from pulmonary edema. Cardiac function index (CFI) and global ejection fraction (GEF) were lower in patients with pulmonary edema (PE group) than in patients without PE (non-PE group) throughout the study period (CFI, P≤0.0119; GEF, P≤0.0348). The PE group showed higher GEDI from days 7 to 10, and higher extravascular lung water index (ELWI) throughout the entire study period compared to the non-PE group (GEDI, P≤0.0094; ELWI, P≤0.0077). CONCLUSIONS: The appropriate preload was kept despite negative net water balance and low CVP. PE after SAH was biphasic, with cardiogenic PE caused by low cardiac contractility immediately after SAH, and hydrostatic PE caused by low cardiac contractility and hypervolemia on and after day 7 of SAH. Pulse contour analysis was useful to monitor this unique circulatory change and effective for detecting cardiopulmonary complications after SAH.

Voltage-sensitive dye imaging analysis of functional development of the neonatal rat corticostriatal projection.

We examined the feasibility of voltage-sensitive dye imaging for detecting the neuronal activity in the neonatal rat corticostriatal projection and analyzed postnatal development of synaptic function in this projection. Coronal slice preparations were dissected from postnatal 3 to 14 day (P3-14) rats and were then stained with the voltage-sensitive absorption dye, NK2761. The transmembrane voltage-related optical changes evoked by cortical stimulation using a bipolar electrode could be recorded simultaneously from many loci in the preparation, using a 464ch hexagonal diode array system. In the striatum, the optical signal was composed of a fast spike-like signal and a slow signal. The slow signal was blocked by DL-2-amino-5-phosphonovaleric acid (APV) and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and enhanced by bicuculline, suggesting that (1) the slow signal includes glutamatergic excitatory postsynaptic potentials (EPSPs) and that (2) inhibitory γ-aminobutyric acid A (GABA(A)) receptor function is expressed in the corticostriatal pathway from the early postnatal stage. We compared the excitatory and inhibitory synaptic responses between the first and second postnatal week preparations, and we showed that (1) in the first postnatal week, excitatory transmission in the corticostriatal pathway is mostly mediated by glutamate, (2) in addition to glutamatergic transmission, other excitatory transmission mechanisms emerge in this pathway until the second postnatal week, and (3) the inhibitory transmission mediated by GABA rapidly develops during the postnatal 2 weeks.

[Subarachnoid hemorrhage due to a ruptured intracranial vertebral artery aneurysm associated with cerebrovascular fibromuscular dysplasia: case report].

Fibromuscular dysplasia (FMD) is comprised of a group of nonatherosclerotic and noninflammatory arterial diseases. Cerebrovascular FMD occurs more frequently in women, and the mean age at which it is diagnosed is 50 years. The most common angiographic pattern of cerebrovascular FMD is the "string-of-beads" deformity at the extracranial internal carotid artery. We report the case of a 52-year-old woman who presented with a sudden severe headache and went into a deep coma. She had been complaining of headaches for 2 weeks, but no specific imaging findings were obtained. A computed tomography scan obtained on admission showed a diffuse subarachnoid hemorrhage (SAH) from the cerebellomedullary cistern to the basal cistern with evidence of clot in the fourth and third ventricles. We performed digital subtraction angiography and made the diagnosis of cerebrovascular FMD. Right carotid angiography and left vertebral angiography showed the classic "string-of-beads" pattern with multiple constrictions of the lumen. Left carotid angiography showed a long segment of tubular stenosis. Right vertebral angiography also revealed the "string-of-beads" pattern and a ruptured aneurysm at the intracranial segment, which presented as a diverticulum-like outpouching. The patient was treated with conservative measures but passed away on the 23rd day of hospitalization. An autopsy was not performed. To our knowledge, during the last three decades, there are only four previous reports which showed intracerebral ruptured aneurysms of the vertebral artery or its branch in adults with cerebrovascular FMD. We demonstrate and discuss the radiologic findings here.

Roles of mammalian sterile 20-like kinase 2-dependent phosphorylations of Mps one binder 1B in the activation of nuclear Dbf2-related kinases.

Mammalian nuclear Dbf2-related (NDR) kinases (LATS1, LATS2, NDR1 and NDR2) play a role in cell proliferation, apoptosis and morphological changes. Mammalian sterile 20-like (MST) kinases and Mps one binder (MOB) proteins are important in the activation of NDR kinases. MOB1 is phosphorylated by MST1 and MST2 and this phosphorylation enhances the ability of MOB1 to activate NDR kinases. The phosphorylated MOB1 can be more effective as a scaffold protein to facilitate the MST-dependent phosphorylation of NDR kinases and/or as a direct activator of NDR kinases. We previously reported that Thr74 of MOB1B is phosphorylated by MST2. Thr12 and Thr35 have also been identified as phosphorylation sites. In this study, we quantified the phosphorylation of Thr74 using the phosphorylated Thr74-specific antibody. Thr74 is indeed phosphorylated by MST2, but the efficiency is low, suggesting that MOB1B can activate NDR kinases without the phosphorylation of Thr74. We also showed that the phosphorylated MOB1B activates NDR1 T444D and LATS2 T1041D, in which threonine residues phosphorylated by MST kinases are replaced with phosphorylation-mimicking aspartic acid, more efficiently than the unphosphorylated MOB1B does. This finding supports that the phosphorylation of MOB1B enhances its ability as a direct activator of NDR kinases.

[Postpartum chronic subdural hematoma following spinal anesthesia: case report].

Chronic subdural hematoma is a rare complication of epidural anesthesia. This report describes the case of a 34-year-old woman who presented with postpartum headache after she received epidural anesthesia for labor pain. The anesthesiologist's record did not show any anesthesia-related complication. Two days after the delivery (on day 2), the patient complained of headache. Postdural puncture headache was diagnosed, so she was administered analgesics, hydration therapy, and bed rest. On day 4, she reported a slight improvement and was discharged. The postural headache persisted even on day 7 after delivery. During the conservative treatment, she had suffered a mild head trauma. On day 13, she started to feel a non-postural and severe throbbing headache. On day 24, she was referred to our department. Bilateral chronic subdural hematoma was confirmed by a computed tomography scan. Physical examination revealed only mild right hemiparesis. Left burr hole trepanation was performed and this was followed by uneventful postoperative course. Right chronic subdural hematoma was managed by conservative treatment, and it completely recovered after 4 weeks. Chronic subdural hematoma should be considered when postpartum patients who have received epidural anesthesia present with mild to severe, persistent, and non-postural headache.

[Case of ruptured multiple cerebral aneurysms associated with primary aldosteronism].

Primary aldosteronism (PA) has been recognized as a relatively benign form of hypertension associated with a low incidence of vascular complications. Recent reports, however, indicate that cerebrovascular accidents are common in PA. We report a case of multiple aneurysms with PA in a middle-aged woman who presented with subarachnoid hemorrhage. A 47-year-old woman with a history of untreated hypertension was referred to our hospital for subarachnoid hemorrhage. Cerebral angiography showed multiple small aneurysms. The initial intervention was aneurysm clipping for a ruptured aneurysm at the bifurcation of the right middle cerebral artery. Despite medication, she continued to suffer from uncontrolled hypertension and hypokalemia. She was diagnosed with PA on the basis of elevated plasma aldosterone, suppressed plasma rennin, and a right adrenal tumor detected by abdominal CT scanning. She underwent several more neck clippings for the remaining aneurysms (unruptured), followed by a total right adrenectomy. Histological examination revealed an adrenal adenoma. After the operation, her blood pressure returned to normal without any vasodepressors. Recent studies have demonstrated that hyperaldosteronism might have direct vasculo-toxic actions, including remodeling, fibrosis, and proliferation. Cerebrovascular accidents caused by PA are reported to have high rates of mortality and recurrence when the PA is overlooked or untreated. Physicians must be alert to the possibility of PA in patients with hypertension and persistent hypokalemia, especially in those who are young or middle-aged. We also recommend screening for intracranial aneurysms by low-invasive magnetic resonance angiography.

Contributions of biological tumor parameters to the incorporation rate of L: -[methyl-(11)C] methionine into astrocytomas and oligodendrogliomas.

We compared the tumor uptake of (11)C-methionine (MET) with positron emission tomography (PET) with the results of a pathological analysis to examine the proliferative potential and microvessel density measured with immunostaining for MIB-1 and factor VIII, respectively, from 33 patients with glioma. The MET uptake in oligodendrogliomas was significantly greater than that in grade 2 astrocytomas and comparable to those in grade 3 and 4 astrocytomas. The MIB-1 index of oligodendroglioma meanwhile was comparable to that of grade 2 astrocytoma. The microvessel area in oligodendroglioma was significantly greater than that in grade 2 astrocytomas and comparable to those in grade 3 and 4 astrocytomas. According to a multivariate statistical analysis, MET uptake ratio was closely correlated with the MIB-1 index among astrocytomas. An increase in the microvessel area in the oligodendrogliomas contributed to the higher MET uptake among the tumors with a low-proliferative index. This information is important for interpreting the results of MET-PET studies for clinical use.

Glioma surgery using a multimodal navigation system with integrated metabolic images.

OBJECT: A multimodal neuronavigation system using metabolic images with PET and anatomical images from MR images is described here for glioma surgery. The efficacy of the multimodal neuronavigation system was evaluated by comparing the results with that of the conventional navigation system, which routinely uses anatomical images from MR and CT imaging as guides. METHODS: Thirty-three patients with cerebral glioma underwent 36 operations with the aid of either a multimodal or conventional navigation system. All of the patients were preliminarily examined using PET with l-methyl-[11C] methionine (MET) for surgical planning. Seventeen of the operations were performed with the multimodal navigation system by integrating the MET-PET images with anatomical MR images. The other 19 operations were performed using a conventional navigation system based solely on MR imaging. RESULTS: The multimodal navigation system proved to be more useful than the conventional navigation system in determining the area to be resected by providing a clearer tumor boundary, especially in cases of recurrent tumor that had lost a normal gyral pattern. The multimodal navigation system was therefore more effective than the conventional navigation system in decreasing the mass of the tumor remnant in the resectable portion. A multivariate regression analysis revealed that the multimodal navigation system-guided surgery benefited patient survival significantly more than the conventional navigation-guided surgery (p = 0.016, odds ratio 0.52 [95% confidence interval 0.29-0.88]). CONCLUSIONS: The authors' preliminary intrainstitutional comparison between the 2 navigation systems suggested the possible premise of multimodal navigation. The multimodal navigation system using MET-PET fusion imaging is an interesting technique that may prove to be valuable in the future.

Possible role of cyclooxygenase-2 in developing chronic subdural hematoma.

Inflammatory cytokines are reportedly involved in the pathogenesis of chronic subdural hematomas (CSH), and the angiogenesis of hematomas has particularly been in focus. Cyclooxygenase-2 (COX-2) is an essential enzyme for the synthesis of prostaglandin E2 (PGE2). The COX-2-PGE2 pathway has been shown to influence angiogenic factors such as vascular endothelial growth factor (VEGF). We investigated the association of COX-2 expression in the dura mater and outer membrane with the pathogenesis of CSH, and suggested a treatment strategy on the basis of this association. Hematoma fluid and serum samples obtained from 37 patients, and samples of the dura mater and outer CSH membrane obtained from 13 patients during the operation were examined in this study. The concentrations of PGE2 in relation to COX-2 in the hematoma fluid were significantly higher than those in the serum. Immunohistochemical analyses revealed COX-2-positive cells in the outer membrane of CSHs. There was a linear and significant relationship between PGE2 concentration in hematoma fluid and the interval from trauma to initial surgery. COX-2 may play a crucial role during the development of CSHs. Our study might lead to the development of anti-COX-2 treatment options that aim to minimize repeat surgery and choose medical therapy by reducing CSH morbidity and recurrence rate in patients with CSH.

[Clinical and operative findings in patients with trigeminal neuralgia caused by brain tumors].

Trigeminal neuralgia (TN) is occasionally caused by cerebellopontine angle (CPA) tumors. Among 243 patients presenting with TN who had been operated on in our institute, 25 (10.3%) were caused by CPA tumors, which consisted of 11 epidermoid, 9 acoustic tumors, and 5 meningiomas. Cases with TN caused by tumors were clinically investigated in comparison with those of idiopathic TN. No significant differences were found concerning sex and the affected side between patient groups with tumors and without tumors. Patients with tumors were significantly younger than those without tumors (p = 0.04). In about 30% of patients of both groups, the trigeminal division of pain extended to two or more branches. In more than half of patients with epidermoid, the affected trigeminal distribution was two or more branches Operative findings demonstrated that the trigeminal nerve was compressed by surrounding vessels in 12 of 25 patients with tumors. The encasement of the trigeminal nerve by the tumor was most frequent affecting pattern in epidermoids, while acoustic tumors and meningiomas tended to compress and distort the nerve. TN disappeared in all patients with tumors at discharge. 5 patients with epidermoid experienced recurrence of TN during the follow-up period. In 4 of them, no tumor regrowth was detected at the time of TN recurrence. The mechanism of TN recurrence without tumor regrowth remains unclear, but may be explained by the arachnoid adhesion around the trigeminal nerve, as described in the previous report.

[The usefulness of whole body FDG-PET/CT in patients with brain metastasis].

In patients presenting with brain metastases, the evaluation for extracranial metastases is important to determine the therapeutic strategies and predict the patients outcome. We investigated the findings of whole-body FDG-PET/CT in 30 patients with metastatic brain tumors. The patients were divided into two groups consisting of 16 patients with precocious or synchronous metastases (PS group), or 14 patients with metachronous metastases (M group), according to the brain metastatic patterns. In all patients of the PS group, the primary site was the lung. In one patient of the PS group, the primary lesion was detected neither by FDG-PET/ CT nor by contrast-enhanced CT or MRI in one patient of the PS group. The primary site of another patient in the PS group was confirmed only by FDG-PET/CT. The sensitivity of FDG-PET/CT in search of primary site was 93.3%, while that of conventional modalities was 87.5%. Maximum standardized uptake value (SUV) of the primary lesions did not show statistically significant difference between groups with single and multiple metastatic brain lesions. SUV also failed to show a statistically significant difference between groups with and without extracranial metastatic lesions. In patients comprising the M group, breast cancer was the most frequent primary site. 3 patients in the M group showed no definite hypermetabolic lesions including the primary sites. Two of them have been clinically independent for more than 20 months. 22 (73.3%) of all patients presented extracranial metastases when brain lesions were found. FDG-PET/CT is a useful modality in detecting the primary cancer and evaluating extracranial systemic metastases. It is important to establish a refined clinical staging system and predict the patient's prognosis based upon the findings of FDG-PET/CT in patients with brain metastasis.

[Clinical and serial angiographic study in patients with subarachnoid hemorrhage of unknown etiology with special reference to the clot distribution of perimesencephalic nonaneurysmal subarachnoid hemorrhage].

We investigated 22 cases with subarachnoid hemorrhage (SAH) of unknown etiology by the initial digital subtraction angiography (DSA). The computed tomography (CT) scans were obtained within 24 hours from onset. Patients were divided into two groups according to SAH distribution in CT on admission; perimesencephalic SAH (PMSAH) and non-PMSAH. The category of patients belonging to the PMSAH group was subdivided into typical or extended pattern of PMSAH. Typical PMSAH pattern of CT is defined as that having the center of clot immediately anterior to the upper brainstem with no definite extension into the anterior interhemispheric fissure (IFH) or sylvian fissure. Extended PMSAH pattern includes the extension of SAH into the anterior IHF or sylvian fissure with the center of the clot similarly located anterior to the upper brainstem. The number of patients with typical PMSAH, extended PMSAH or non-PMSAH was 2, 6, or 14, respectively. Follow-up DSA was obtained in 20 Spatients. The 2nd DSA revealed the lesions as bleeding sources in 3 patients with non-PMSAH. Eight patients further underwent the 3rd DSA, which identified bleeding sources in 3 patients with non-PMSAH. No bleeding sources were detected by serial DSA in PMSAH patients. Patients with extended PMSAH may be managed like those with typical PMSAH. The 3rd DSA is required if the 2nd DSA fails to identify the bleeding source in non-PMSAH. The 2nd DSA may be necessary in PMSAH patients because of the possible identification of bleeding sources. Optimal diagnostic protocol to confirm the bleeding sources should be established in SAH patients of unknown etiology.

Involvement of accumulated NOS inhibitors and endothelin-1, enhanced arginase, and impaired DDAH activities in pulmonary dysfunction following subarachnoid hemorrhage in the rabbit.

We designed the present experiments to investigate the involvement of endogenous nitric oxide synthase (NOS) inhibitors, dimethylarginine dimethylaminohydrolase (DDAH) as a hydrolyzing enzyme of the NOS inhibitors, NOS, arginase which shares l-arginine as a common substrate with NOS, and endothelin-1 (ET-1) in the pulmonary dysfunction after induction of experimental subarachnoid hemorrhage (SAH) in the rabbit. SAH was induced by injecting autologous blood into the cisterna magna, and controls were injected with saline. On day 2, pulmonary arteries were isolated for determinations. A significant impairment of the endothelium-dependent relaxation (EDR) caused by acetylcholine was found in 20 cases (43.5%) out of 46 SAH animals, and the same animals exhibited accompanying the significantly impaired cyclic GMP production, accumulated endogenous NOS inhibitors, attenuated DDAH activity, enhanced arginase activity and accumulated ET-1 within the vessel wall. Meanwhile, there were no differences in endothelial NOS activity per se and sodium nitroprusside-induced relaxation between the animals with an impaired EDR and those without such a change. ET-1 content within aortic wall was increased with concomitant decrease in cyclic GMP production after the intraperitoneal application of authentic monomethylarginine as a NOS inhibitor in the rat. The current results suggest that accumulated endogenous NOS inhibitors and enhanced arginase activity possibly bring about the impaired NO production, thereby attenuating the EDR and contributing to the accumulation of ET-1 within the vessel wall. The accumulated endogenous NOS inhibitors at least partly result from the decreased DDAH activity. These alterations may be relevant to the pulmonary dysfunction after induction of SAH.

Voxel- and ROI-based statistical analyses of PET parameters for guidance in the surgical treatment of intractable mesial temporal lobe epilepsy.

OBJECTIVE: Positron emission tomography (PET) can be used to locate epileptic foci in patients with mesial temporal lobe epilepsy (MTLE) by measuring multiple parameters of the brain. We investigated a series of patients with MTLE using PET measurements of three parameters: the cerebral blood flow measured with [15 O] H2O, the uptake of [18F] fluorodeoxyglucose (FDG), an index of the cerebral metabolism rate of glucose, and the distribution volume (DV) of [11C] flumazenil (FMZ), an index of the binding potential of central benzodiazepine receptor. We compared predictive values obtained from two methods: a voxel-based statistical analysis using statistical parametric mapping (SPM) and an asymmetry index obtained by placing regions of interest (ROIs) on PET images. METHODS: Preoperative PET data of 11 patients with surgically confirmed MTLE were retrospectively examined. In the voxel-based analysis, the PET data were analyzed using SPM99 by statistically comparing the voxel values of PET parameters between individual patients and the mean values of 12 normal volunteers. Voxels with values significantly lower than the normal control values were mapped on a standard brain atlas. In the ROI-based analysis, the asymmetry index was calculated to depict ROIs with abnormally decreased values when compared with the contralateral side. RESULTS: (1) Statistical parametric mapping and ROI analyses of the FDG uptake correctly determined epileptic temporal lobe in 73% and 82%, respectively. (2) The decreased DV of FMZ depicted by SPM revealed the mesial temporal pathology in 91%. CONCLUSIONS: Positron emission tomography measurement of FDG uptake was most sensitive in detecting the side of the epileptic focus. On the other hand, SPM analysis of the DV of FMZ was the most sensitive method for delineating the actual epileptic focus.