Takashi Hatayama

Comparison of transcranial Doppler investigation of aneurysmal vasospasm with digital subtraction angiographic and clinical findings.

OBJECTIVE Transcranial Doppler (TCD) findings for evaluation of the severity of vasospasm (VSP) in patients with ruptured aneurysmal subarachnoid hemorrhage are controversial. To clarify these TCD findings, intra-arterial digital subtraction angiography was used to simultaneously investigate the angiographic features of cerebral vessels and the cerebral circulation time (CCT). METHODS Fifty patients with ruptured aneurysms, for whom computed tomographic scans indicated Fisher Grade III subarachnoid hemorrhage, were investigated. Aneurysmal neck clipping was performed in the acute stage. The mean flow velocity (MFV) at the M1 segment was measured using TCD ultrasonography. Intra-arterial digital subtraction angiography was used to simultaneously investigate angiographic features and CCTs on Days 7 to 13. The CCT was defined as the time difference between the two peaks in optical density curves recorded at the carotid artery (C3-C4 portion) and the ascending vein, after contrast material injection. Angiographic VSP was categorized using a modification of the Fisher classification. RESULTS Angiograms for 9, 25, and 16 patients showed no, slight to moderate, and severe VSP, respectively. The MFVs of the patients with no, slight to moderate, and severe VSP were 70, 115, and 116 cm/s, respectively. No significant difference among the three groups could be observed. The mean CCTs of the patients with no, slight to moderate, and severe VSP were 4.1, 4.6, and 6.5 seconds, respectively. The CCTs of the patients with severe VSP differed significantly from those of the patients with no or slight to moderate VSP. The patients with severe VSP were divided into two groups. One group included eight patients with severe VSP at proximal sites (the internal carotid artery to the M1 segment), and the other included eight patients with severe VSP extending to the M2 segment and more peripheral sites. The mean CCT of the former group (5.3 s) was significantly different from that of the latter (7.5 s), and the MFV of the former group (128 cm/s) was significantly higher than that of the latter (81 cm/s). The clinical outcomes for the latter patients were more serious than those for the former patients. CONCLUSION This study suggests that the MFV at the M1 segment is inadequate for estimation of the severity of VSP extending to vessels more peripheral than the M1 segment. Furthermore, severe VSP extending to more peripheral sites can produce more serious ischemic insults, compared with that localized to basal vessels. Patients with negative TCD results and clinical features suggesting the development of VSP should undergo quantitative investigation of cerebral circulatory parameters, such as the CCT, using intra-arterial digital subtraction angiography.

Metastasis of malignant struma ovarii to the cranial vault during pregnancy.

Malignant struma ovarii is a rare type of ovarian teratoma; only 16 cases with distant metastases have been reported previously. We report an extremely rare case of malignant struma ovarii metastatic to the cranial vault, which developed during pregnancy. A 28-year-old woman in the 26th week of pregnancy, who had undergone resection of an ovarian tumor 3 years previously, noticed a mass in her left frontal region that had enlarged gradually in 6 months. Magnetic resonance imaging revealed a massive extradural tumor growing through the cranium. Under fetal heart monitoring, the patient underwent total resection of the tumor, including the adjacent cranial bone and dura, and a healthy infant was delivered at full term. Pathological examination showed that the tumor was a follicular adenocarcinoma. Because there was no abnormality in the patients thyroid gland, this tumor was considered to be a metastasis from the ovarian tumor, a malignant struma ovarii, resected 3 years previously. The management of brain tumor during pregnancy is also discussed.

Coincidental pituitary adenoma and parasellar meningioma: case report.

We report a patient who had pituitary adenoma and parasellar meningioma coincidentally, with neither irradiation nor a history of head injury. Preoperative computed tomographic (CT) scan had shown a large intrasellar mass with ring-like enhancement; in contact with this mass, another well-enhanced mass had been shown. Histopathologically, the intrasellar mass was diagnosed as chromophobic pituitary adenoma and the other mass as meningotheliomatous meningioma. We present clinical, radiological, and histopathological findings and discuss previously reported cases of coincidental pituitary adenoma and meningioma without irradiation. This is the first case report since the advent of CT that pituitary adenoma and parasellar meningioma in contact with each other could be clearly demonstrated by CT.

Primary pineal melanoma with long-term survival: Case report

A rare case of primary pineal melanoma is reported. The patient was a 53-year-old woman who complained of a severe headache. Computed tomography and magnetic resonance images revealed obstructive hydrocephalus caused by a mass lesion in the pineal region. A biopsy was performed through an occipital transtentorial approach. A black pigmented solitary tumor was seen without leptomeningeal dissemination. Histologic examination revealed melanoma. Chemotherapy consisting of dacarbazine, ACNU, vincristine, and interferon was used. Follow-up imaging studies showed dramatic reduction of the tumor without recurrence for 4 years. This report demonstrates that a solitary primary intracranial melanoma without leptomeningeal dissemination and with rare mitoses may yield a good result with chemotherapy.

Changes in Cerebral Blood Flow after Carotid Endarterectomy

We evaluated changes in cerebral blood flow (CBF) after carotid endarterectomy (CEA) in patients with internal carotid (ICA) stenosis. We studied 46 patients with ICA stenosis who underwent CEA. The mean age of the patients was 63 years, and their mean ICA stenosis was 73%. CBF in the middle cerebral artery territory was measured with xenon-enhanced CT tomography (Xe-CT) before and 3 weeks after CEA. In addition, cerebrovascular reactivity (CVR) was measured after intravenous administration of acetazolamide (ACZ) in 16 patients. There was no significant relationship between the degree of stenosis and CBF. Ten patients had decreased CBF before CEA, and CBF improved in nine of these after CEA. The CVR in 6 of 7 patients with impaired CVR before CEA improved to varying degrees after CEA. The CBF in patients with ICA stenosis varied according to the degree of collateral circulation. In conclusion, CEA can increase CBF and improve CVR in patients with low CBF or low CVR by restoring blood flow through the ICA.

Retraction of the Internal Carotid Artery and Measurement of the Regional Cerebral Blood Flow in Basilar Top Aneurysmal Surgery

In the surgery of the basilar top aneurysm, the internal carotid artery is often retracted to obtain a clear surgical field, which may lead cerebral ischemia. To prevent this the followings are noted: 1. The cross circulation especially through the anterior communicating artery is estimated before surgery, 2. The internal carotid artery is retracted at the elastic, less arteriosclerotic portion, 3. Cerebral protecting agents are administered, 4. A time keeper is arranged, 5. The duration of retraction is basically five minutes, 6. The regional cerebral blood flow and the EEG are monitored, 7. The retraction of the internal carotid artery must be extracted when there is a marked reduction of the regional cerebral blood flow, 8. The retraction of the internal carotid artery must be extracted when the slowing of the EEG is observed. In this report, a 74-year-old female patient with a basilar top aneurysm associated with a persistent primitive hypoglossal artery is described. The surgery was performed on day 5 after subarachnoid hemorrhage through a pterional approach by retracting the internal carotid artery. A thermal diffusion flow probe was used to monitor the regional cerebral blood flow during surgery. The regional cerebral blood flow was not reduced, or was reduced little, by the retraction of the internal carotid artery, and returned to the level before retraction by the extraction in the early phase. But later, after several retractions, the reduction of the regional cerebral blood flow became rapid by the retraction, and postischemic hyperemia was observed after the extraction. In this case the reduction of the regional cerebral blood flow was not so severe (less than 50%) that the operation could be continued safely, and the aneurysm was clipped successfully. The usefulness and significance of monitoring the regional cerebral blood flow during retraction of the internal carotid artery are discussed.