Yuji Uematsu

The usefulness and problem of intraoperative rapid diagnosis in surgical neuropathology

Intraoperative rapid diagnosis has been a useful neurosurgery tool for maximal resection and minimal morbidity. However, only a few studies have been conducted regarding diagnostic accuracy and associated problems. The present study reviews our experience in treating patients and investigates the accuracy and problems associated with intraoperative rapid diagnosis in surgical neuropathology. There were 180 cases of intracranial lesions excluding pituitary lesions. The patients consisted of 89 males and 91 females, ranging from 5 months to 84 years, with a mean age of 46 years. Of the 180 cases, 152 cases received open surgery, 28 cases had stereotactic surgery including a biopsy and were histologically verified. The correlation between the intraoperative diagnosis and the final diagnosis overall was seen in 172 of 180 cases, proving a high diagnostic sensitivity of 95.6%. No correlation was seen in 8 cases (4.4%). The diagnostic inaccuracy was seen in the grading of gliomas and the diagnosis of undifferentiated malignant tumors such as undifferentiated metastatic carcinomas, primitive neuroectodermal tumors (PNETs), and sarcomas. It was also recognized in rare types of histology such as gliomatosis and xanthomatous lesions. These results suggested that the intraoperative rapid diagnosis was quite useful, but that we should also maintain a cautious attitude.

The recurrence of primary intracranial germinomas

SummaryTwenty three cases of primary intracranial germinomas including five cases of germinomas with syncytiotrophoblastic giant cells are studied and analyzed, with special reference to the recurrence under radiotherapy. The follow-up period for all cases was 7 months to 12 years (average: 5.8 years) with that for pure germinomas ranging from 8 months to 12 years (average: 5.7 years) and that for germinomas with syncytiotrophoblastic giant cells ranging from 7 months to 11 years (average: 6.3 years). Late recurrence was observed in three cases (3/23, 13%), developing outside of the initial irradiation field.With regard to recurrence, significant correlation to radiation fields was evident, while it was not to radiation doses. Furthermore, germinoma with syncytiotrophoblastic giant cells showed a more significant tendency to recur than pure germinoma. The radiotherapy of germinomas is discussed and the clinical features of germinoma with syncytiotrophoblastic giant cells are presented.

Gamma knife radiosurgery for neuroepithelial tumors: Radiological and histological changes

Gamma knife radiosurgery (RS) has been introduced as a modern therapy for brain tumors. However, the effects of RS for neuroepithelial tumors are still obscure. The present study investigates the radiological and histological changes after RS to elucidate the biological effect. There were seven cases (two males and five females), ranging from 4 to 71 years with a mean age of 33 years. Two cases were located in the brainstem, another two in the cerebellum, and one each in the thalamus, the hypothalamus, and the frontal lobe. Histologically, two cases had gangliogliomas, four astrocytomas (1 pilocytic, 1 fibrillary, 2 anaplastic), and one glioblastoma. RS was performed after surgery with a central dose of 30–36 Gy. All cases were evaluated radiologically on MRI before and after RS. Four cases (3 astrocytomas and 1 glioblastoma) which neurologically deteriorated after RS were reoperated. These cases were examined using HE and immunohistochemical studies with antibodies of CD34, α‐smooth muscle actin (SMA), p53, p2l and MIB‐1 on the sections before and after RS. MRI demonstrated perifocal edema and intratumoral hypointensity on T2 weighted imaging (T2WI), suggesting radionecrosis in most of the cases within 6 months after RS. In the central part of the RS, destructive changes were observed in the tumor cells and endothelial cells: decrease in the tumor cell population, coagulation necrosis, and fibrinoid degeneration of vascular walls were revealed. In the peripheral part, however, some tumors contained viable tumor cells intermingled with blood vessels showing endothelial and pericytic proliferations. The increase of MIB‐1 staining index was found in only one case. The p2l immunoreactivity was increased in endothelial cells, although the p53 immunoreactivity was unchanged. These results suggested that radionecrosis occurred earlier and more frequently in neuroepithelial tumors after RS than after conventional radiation.

Hemorrhagic Infarction after Vasospasm Due to Ruptured Cerebral Aneurysm

Hemorrhagic infarction after vasospasm is a rare condition in patients with aneurysmal subarachnoid hemorrhage (SAH). Induced hypertensive therapy is used for patients with vasospasm, but this treatment has a risk of inducing hemorrhagic infarction. A total of 221 patients whose first computed tomographic (CT) scans were examined within 2 weeks after SAH were investigated for this study. There was symptomatic vasospasm in 99 (45%), cerebral infarction in 37 (17%), and hemorrhagic infarction in 13 (6%). Hemorrhagic infarction usually occurred 20 to 30 days after aneurysmal rupture; this period corresponds with the remission stage of the vasospasm. On CT scans, the hemorrhagic infarction was revealed as a leaky hemorrhage in a low density area in 11 cases, and a massive hemorrhage with mass effect was seen in 2 cases. These findings suggest that hemorrhagic infarction after vasospasm may sometimes be fatal. Cerebral blood flow autoregulation in patients with vasospasm was normal or of a hypertensive type during the remission stage of vasospasm, when hemorrhagic infarction usually appeared. This finding shows that induced hypertension therapy is ineffective during this stage; it should be stopped by this stage because it is ineffective and also may aggravate hemorrhagic infarction.

Interhemispheric Neuroepithelial Cyst Associated with Agenesis of the Corpus callosum

This report describes a neonatal case in whom a large interhemispheric cyst associated with agenesis of the corpus callosum was revealed by fetal ultrasonography and demonstrated by MRI to be multilobulated. Endoscopic fenestration of cysts was initially designed in view of the development of the patient’s brain and surgical invasiveness. One year later, when motor paresis of the left arm and progressive enlargement of the cyst on MRI were revealed, open surgery was performed. The histological diagnosis was a neuroepithelial cyst with the feature of choroid plexus epithelia. The clinicopathological features of interhemispheric epithelial cysts associated with agenesis of the corpus callosum are reviewed in the light of differential diagnosis and therapeutic considerations.

Ictal asomatognosia due to dominant superior parietal cortical dysplasia

We report a 23-year-old man with left dominant parietal cortical dysplasia manifesting as ictal asomatognosia. The man had experienced seizures, during which he underwent ictal asomatognosia as a feeling of loss of his right extremities. Scalp electroencephalography (EEG) showed interictal discharges in the left parietal region of his brain. Magnetic resonance fluid-attenuated inversion recovery (FLAIR) imaging revealed a hyperintense lesion in the left superior parietal lobule. A [(123)I]-iomazenil (IMZ) single-photon-emission CT scan demonstrated an area of low IMZ binding coincident with the lesion observed in the MRI scan. Invasive EEG monitoring showed ictal discharges in the cortex posterior to the postcentral sulcus. High-frequency electrical stimulation of the same area of the cortex also induced asomatognosia of the patients right forearm. We performed a corticectomy of the anterior part of the superior parietal lobule, which resulted in no new neurological deficits. The seizures disappeared after surgery with the maintenance of preoperative medication. Therefore, the anterior part of the superior parietal lobule may be a symptomatogenic zone for ictal asomatognosia.

A possible involvement of central atrial natriuretic peptide in cerebral cortical microcirculation.

The possible involvement of atrial natriuretic peptide (ANP) in cerebral cortical microcirculation was investigated in rats by means of laser-Doppler flowmetry and immunohistochemistry. In the laser-Doppler study, local cerebral blood flow (LCBF) changes after the administration of 10(-6) to 10(-8) mol/LANP solution or vehicle (saline solution) as an intracortical injection for 5 minutes were continuously monitored throughout the 30 minutes of the study and were expressed as percentages of preinjection values represented as 0%. The administration of 10(-6) to 10(-8) mol/LANP caused a significant decrease in LCBF; the onset of LCBF responses occurred within a few minutes after the start of the injection and the decrease in LCBF reached the maximum level within 7 to 10 minutes after the completion of the administration, after which LCBF gradually recovered. In the immunohistochemical study, no specific ANP immunoreactivity was found associated with the intraparenchymal blood vessels; however, ANP-immunoreactive neurons were observed primarily in the hypothalamus and septum, in which high concentrations of ANP-containing neurons have been identified. The data from the laser-Doppler study suggest that central ANP may produce a vasoconstriction of the intraparenchymal blood vessels, regardless of whether through direct action on these vessels or through the mediation by some system in the central nervous system. Because there is no evidence for ANP-containing nerves around these vessels, the role of central ANP in the cerebral circulation must await identification of the source of perivascular ANP.

Effect of metabolic syndrome components and their clustering on carotid atherosclerosis in a sample of the general Japanese population

The objective of this study was to investigate the impact of metabolic syndrome (MS) on carotid atherosclerosis in a Japanese population. A total of 1727 subjects (805 males and 922 females) were included. Intima-media thickness (IMT) was measured using ultrasonography. To evaluate the independent determinants of IMT, a stepwise multiple regression analysis was employed that included age, current smoking habit, LDL-C, HbA1c and the MS components (SBP, DBP, TG, HDL-C, FBG, and WC) as independent variables. Multivariate regression analyses were performed to determine the independent associations of the MS components with IMT. In males, age (β=0.383, P<0.001), SBP (β=0.237, P<0.001), LDL-C (β=0.188, P<0.001), current smoking habit (β=0.124, P=0.007) and HbA1c (β=0.110, P=0.014) were significantly associated with IMT. In females, age (β=0.474, P<0.001), SBP (β=0.130, P=0.003) and FBG (β=0.110, P=0.038) were significantly associated with IMT. The present study demonstrated that an elevated number of MS components, with or without central obesity, is associated with higher IMT. Among the analyzed components, hypertension has the strongest association with higher IMT.

Orthostatic Blood Pressure Changes and Subclinical Markers of Atherosclerosis

BACKGROUND Using a simple standing-up test in normotensive subjects, we evaluated orthostatic upright postural blood pressure (BP) changes and autonomic nervous function, as well as the relationship between orthostatic BP changes and subclinical markers of atherosclerosis. METHODS A total of 515 normotensive subjects aged 35-75 years (58.4±10.0 years) were enrolled. We measured body mass index (BMI), systolic BP (SBP) and diastolic BP (DBP), serum lipids, hemoglobin A1c (HbA1c), high-sensitivity C-reactive protein (hs-CRP), and urinary albumin-to-creatinine ratio. Brachial to ankle pulse wave velocity (baPWV) and carotid mean intima-media thickness (IMT) were measured. Participants underwent a simple standing-up test involving sitting then standing for 2 minutes each, followed again by sitting. To evaluate autonomic fluctuations, we calculated the coefficient of variation of the R-R interval, the ratio of low to high frequency heart rate variability (LF/HF), and the coefficient of component variance of high frequency. RESULTS SBP and DBP decreased when standing, with a reduction of SBP when changing position of -8.0±10.2mm Hg. Orthostatic hypotension (OH) produced a significantly higher SBP than without OH. The baPWV was significantly higher in OH than in without OH. Stepwise regression analysis adjusted for age, sex, BMI, baseline SBP, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, fasting glucose, HbA1c, hs-CRP, IMT, late systolic peak of the pressure wave form (SBP2), and baPWV confirmed that baPWV, SBP2, and triglycerides were independently related to orthostatic BP changes. Multiple regression analyses showed that a decrease in SBP as well as baseline SBP, age, BMI, and fasting glucose were independent determinants of PWV. CONCLUSIONS We have shown that increased arterial stiffness was associated with OH during a standing-up test. Arterial stiffness may contribute to greater BP responses to postural changes from standing.

Intraoperative hemorrhage in medulloblastoma: a case report and review of the literature

HeadingAbstract Object. We present the first case of intraoperative hemorrhage in a medulloblastoma. Case report. A 10-year-old girl presented with a 4-week history of headache, nausea, and vomiting. Radiological examination showed a space-occupying mass in the cerebellar vermis. Surgical removal was performed via a midline suboccipital approach. When the dura was incised and the occipital sinus was ligated after suboccipital craniectomy, bleeding occurred in the tumor. Macroscopically, hematoma was found only in the left part of the tumor and not in the right part. Microscopically, different architectures of tumor vessels, thin-walled and thick-walled, were found between the left part and the right part, respectively. The tumoral contents and hematoma were totally removed. Histological examination revealed a medulloblastoma. Conclusion. We experienced a very rare case of medulloblastoma in which intratumoral hemorrhage occurred during operation. We speculate that ligation of the occipital sinus and thin-walled vessels within the tumor might have caused the hemorrhage in our case.