Haemodynamic and metabolic changes following extra-intracranial bypass surgery.

In order to study the haemodynamic and metabolic changes following bypass surgery, the regional cerebral blood flow (rCBF), the oxygen extraction fraction (rOEF), the cerebral metabolic rate of oxygen (rCMRO2), and the cerebral blood volume (rCBV) were measured using a positron emission tomograph (PET) on 13 patients who had unilateral internal carotid artery and/or middle cerebral artery occlusion. The patients were divided into two subgroups according to pre-operative rOEF values from the arterial occlusion side: the misery perfusion group, which had high rOEF values (> or = 0.56), and the coupling perfusion group, which had normal rOEF values (0.38-0.48). A post-operative PET study was performed 1-2 months and/or 1-5 years following the surgery. Six of the misery perfusion cases showed a post-operative CBF increase, where an accompanying OEF decreased to its normal level, indicating an attenuated misery perfusion state. The CMRO2 values, however, remained low. The other 7 coupling perfusion cases had an ipsilateral CBF increase in the earlier PET study. We conclude that misery perfusion is attenuated following bypass surgery, although the procedure does not consistently improve oxygen metabolism.

[Renal cell carcinoma metastasizing to choroid plexus of lateral ventricle; a case report].

A rare case of renal cell carcinoma metastasizing to the choroid plexus of the lateral ventricle is reported. A 59-year-old woman was admitted to our institution on November 26, 1987 complaining of left-half headache for one month. She had a past history of right nephrectomy due to renal cell carcinoma 4 years before admission, and of right radical mastectomy due to breast cancer 10 years before admission. She had no abnormal neurological findings and laboratory results were normal. CT scan revealed a well-circumscribed, apparently homogeneously enhancing mass in the left lateral ventricle with mild ventricular dilatation. Left vertebral angiogram showed a tumor stain fed by the left posterior choroidal artery. The most likely diagnosis was thought to be metastasis of renal cell carcinoma. The patient underwent the operation for tumor removal via the posterior interhemispheric transcallosal approach 14 days after admission. A histological examination of the tumor determined the diagnosis of clear-cell type renal cell carcinoma. The operation was uneventful and the patient was discharged 20 days after operation without neurological deficit. But she had recent-memory disturbance, low activity, and gait disturbance in May 1989. CT scan revealed ventricular dilatation and tumor recurrence at the same site. She also suffered from diabetes due to the regrowth and invasion of primary tumor to the pancreas. She was discharged free of neurological defects after ventriculo-peritoneal shunt. In December 1989, she gradually deteriorated due to the regrowth of the intraventricular metastatic lesion, and now she is bedridden. Choroid plexus metastasis is quite rare, and, to our knowledge, only three cases have been described.

Sequential changes in cerebral blood flow and metabolism in patients with subarachnoid haemorrhage.

Haemodynamic and metabolic sequences were investigated in nine patients having subarachnoid haemorrhage (SAH) up to 3 months following aneurysmal rupture, using positron emission tomography (PET). In the pre-spasm stage (2-4 days after SAH) cerebral blood flow (CBF, ml/100 ml/min) was 45 +/- 11, the cerebral metabolic rate of oxygen (CMRO2, ml/100 ml/min) was 2.68 +/- 0.50, and cerebral blood volume (CBV, ml/100 ml) was 5.5 +/- 1.2. CBF within the normal range and a relatively low CMRO2, indicated relative hyperaemia. This was possibly due to the direct toxic effect of SAH on the brain metabolism. CBV was considerably elevated. The spasm stage (6-15 days after SAH) showed CBF values of 39 +/- 7, CMRO2 values of 2.42 +/- 0.50, and CBV values of 5.4 +/- 1.7. CBF decreased significantly (p less than 0.05 vs pre-spasm stage), and CMRO2 also tended to decrease, while they were coupling. It is likely that this may have been induced by vasospasm. Thereafter, the PET parameters normalized gradually. During all the stages studied, significant laterality of the PET parameters was not observed. This may be because SAH and vasospasm provide diffuse pathophysiological conditions for the entire brain and cerebral arteries.

[Problems of surgical treatment for multiple intracranial aneurysms].

A series of 105 patients presenting with multiple aneurysms and subarachnoid hemorrhage (SAH) were operated on for ruptured and unruptured aneurysms between 1976 and 1984. Clinical factors other than the severity of SAH affecting the outcomes included: 1) Misdiagnosis of the location of a ruptured aneurysm among multiple aneurysms resulted in poor outcomes because of multiple surgical approaches or rebleeding during the acute period. 2) Combinations of aneurysmal locations requiring multiple surgical approaches, such as interhemispheric and transsylvian, during the acute stage caused worse outcomes than with multi-stage surgeries. If an unruptured aneurysm could not be reached during the initial exposure, multi-stage surgery was safe if the ruptured aneurysm had been clipped during the acute period. 3) Complications occurring during unruptured aneurysm surgery. The patient's age, the location and size of the unruptured aneurysms were significant factors in the clinical prognosis. Surgery for unruptured aneurysm caused 1.8% morbidity in patients between 28 and 55 years, but 18.0% morbidity in patients over 56 years of age. Surgery for internal carotid artery aneurysms resulted in 14.8% overall morbidity. Surgery for middle cerebral and anterior cerebral artery aneurysms caused below 5% morbidity. Postoperative morbidity in patients with aneurysms less than 5 mm in diameter was 1.3%, and with aneurysms measuring 10 mm or more, 20%. The optimum treatment for multiple aneurysms with SAH should be based on all factors of the patient's condition, including the unruptured aneurysms.

[Treatment for serious cases of ruptured intracranial aneurysms with severe subarachnoid clot].

Forty-one serious cases of ruptured intracranial aneurysms with severe subarachnoid clot were clinically analyzed, with special emphasis on the prognosis, pathophysiology, and surgical indications. All cases had thick subarachnoid clot without concurrent intracerebral hematoma and/or intraventricular hematoma causing mass signs on the CT scan. In this series, 23 cases underwent radical surgery while in the acute stage, 18 cases were treated conservatively (including 5 cases treated only by continuous ventricular drainage). The criterion for determining the degree of severity was defined as either a "semicoma" or "coma" state just prior to radical surgery for the radically-operated group, with the same designations for the conservative group at their time of admission. All patients except two in the conservatively-treated group died due to primary brain damage caused by massive subarachnoid hemorrhage. The two remaining cases died from other complications. On the other hand, the outcome for the 23 surgically-treated patients was as follows: Three (13%) fully recovered; three (13%) were capable of self-management; eight (34.8%) were partially or fully dependent. Nine (39.1%), died. In the radically-treated group, pre-operative factors that might predict clinical outcome were investigated. Those factors were the neurological grade, the brain-stem response, the response after the rapid administration of 20% Mannitol (300-900 ml), and the length of time from the last bleeding episode to the time that radical surgery was performed. It was recognized that there was no relationship between the neurological grade just prior to radical surgery and the outcomes in the serious cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of the clinical results of STA-MCA anastomosis and the medical treatment in the cerebral low perfusion patients with viable brain tissue.

The long-term clinical results of STA-MCA anastomosis as well as the medical treatments were compared in cases that were confined as having a focal cerebral perfusion deficit with viable brain tissue, based on either the drug induced EEG and evoked potential test (DEE test) and/or by positron emission tomography (PET). The criteria for viable cerebral tissue was determined by the following four conditions: (1) functional reversibility could be confirmed by the DEE test; (2) a haemodynamic process could be found in the DEE test; (3) a haemodynamic compromise could be confirmed in the PET study; (4) misery perfusion could be confirmed in the PET study. From 1975 to 1989, 55 cases were confirmed as having viable brain tissue according to the DEE test and the PET study. Of the 55 cases, bypass surgery was performed on 35. Conservative treatment was given to the other 20 cases. There were 3 cases of perioperative neurological deterioration. One was permanent and the other 2 were transient. Results of the long-term follow up are as follows, Ipsilateral attack: 1 case (2.0%) received surgery, and 7 cases (35%) received conservative treatment. Re-attack in the contralateral or posterior circulation: 6 cases (17.2%) received surgery, and 1 case (5%) received conservative treatment. Seventy-seven per cent of the surgical cases improved or had no change in the final functional status, while only 55% of the conservative group either improved or showed no change. The incidence of ipsilateral cerebral ischaemia was significantly low in the surgical group. Contralateral and/or posterior circulation ischaemia tended to be high in this group, however.(ABSTRACT TRUNCATED AT 250 WORDS)

[Regional effects of craniotomy on cerebral circulation and metabolism: PET study on the un-ruptured aneurysmal surgery].

Regional effects of craniotomy on cerebral circulation and metabolism, such as regional cerebral blood flow (rCBF), regional cerebral oxygen consumption (rCMRO2), regional oxygen extraction fraction (rOEF), and regional cerebral blood volume (rCBV) were examined by a PET (positron emission tomography) study concerning surgery that was performed on unruptured aneurysm patients. Eight patients with intracranial un-ruptured aneurysms were studied pre- and post-operatively by the 15O labelled-gas steady-state method, using HEADTOME-III. All patients underwent aneurysmal surgery performed by the transsylvian approach. There was a significant increase in the mean OEF values taken from the whole-brains of 8 patients, but there was not a significant change in CBF, CMRO2 or CBV. The increase in OEF was caused by decrease of O2 content, which was caused by post-operative decrease in the Hb value. So, this OEF increase was not the direct effect of craniotomy. In 2 patients, the rCBF and rCMRO2, in the fronto-temporal region (where craniotomy was performed) increased post-operatively. This regional effect suggests transient reactive hyperemia following compressive ischemia during the operative procedure, and metabolic demands for recovery of brain function. In 2 other patients, who had relatively low rCBFs during the pre-operative study, rCBF and rCMRO2 in the bi-frontal region had decreased more at the post-operative study. This change appears to have been caused by removal of cerebrospinal fluid and depression of the frontal lobe. From this study, it becomes evident that the regional effect of craniotomy on cerebral circulation and metabolism is not so great, when adequate microsurgical techniques are used.

[Vascular responses in cerebrovascular "Moyamoya" disease--evaluated by positron emission tomography].

We investigated cerebral blood flow and metabolism, and cerebral vascular response in 9 patients with cerebrovascular Moyamoya disease or unilateral Moyamoya phenomenon using positron emission tomography (PET). The subjects consisted of 5 men and 4 women, and were from 9 to 60 years old. Five patients had bilateral occlusion in the carotid fork with Moyamoya vessels (fulfilled the criteria of cerebrovascular Moyamoya disease), and four patients had unilateral Moyamoya phenomenon. The PET scanner used was the HEADTOME III, of which spatial resolution in clinical use was 10 mm full width at half-maximum (FWHM) in the image plane. Cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO2), cerebral oxygen extraction fraction (OEF), and cerebral blood volume (CBV) were measured in resting state by the 15O-labelled gases steady state method in every patient and 22 normal controls (17 men and 5 women, and from 26 to 64 years old). Consecutively cerebral vascular responses were measured by H215O autoradiographic method in resting state, hypercapnia, hypocapnia, and hypertension. Forced hypercapnia, hypocapnia, and hypertension were achieved by 7% CO2 inhalation, hyperventilation, and venous infusion of angiotensin II, respectively. CMRO2 of the whole brain was significantly lower in patients than in normal controls (p less than 0.05), and CBV of the lentiform nucleus significantly increased in patients (p less than 0.01). This reflected Moyamoya vessels in the basal ganglionic regions. In 3 of 5 patients with bilateral Moyamoya vessels, CBF and CMRO2 in the symptomatic cerebral hemisphere were lower than that in the nonsymptomatic hemisphere.(ABSTRACT TRUNCATED AT 250 WORDS)

Oxygen extraction fraction at maximally vasodilated tissue in the ischemic brain estimated from the regional CO2 responsiveness measured by positron emission tomography.

The oxygen extraction fraction (OEF) at maximally vasodilated tissue in patients with chronic cerebrovascular disease was evaluated using positron emission tomography. The vascular responsiveness to changes in PaCO2 was measured by the H2(15)O autoradiographic method. It was correlated with the resting-state OEF, as estimated using the 15O steady-state method. The subjects comprised 15 patients with unilateral or bilateral occlusion and stenosis of the internal carotid artery or middle cerebral artery or moyamoya disease. In hypercapnia, the scattergram between the OEF and the vascular/responsiveness to changes in PaCO2 revealed a significant negative correlation in 11 of 19 studies on these patients, and the OEF at the zero cross point of the regression line with a vascular responsiveness of 0 was 0.53 +/- 0.08 (n = 11). This OEF in the resting state corresponds to exhaustion of the capacity for vasodilation. The vasodilatory capacity is discussed in relation to the lower limit of autoregulation.

[Oxygen extraction fraction and cerebrovascular reactivity to PaCO2 changes in ischemic brain measured by positron emission tomography].

Interrelations between oxygen extraction (OEF) and cerebrovascular reactivity to PaCO2 change (VRCO2) in ischemic brain were measured by the 15O gases steady state method and the H215O autoradiographic method using a positron emission tomography. OEF at rest and VRCO2 for hypercapnia and hypocapnia were assessed successively in five cross sections of 10 mm image resolution. With each study correlation coefficients between OEF and VRCO2 were calculated using 30 to 40 regions of interest. In hypercapnic measurements those which had a larger ischemic region resulted in a higher incident of a negative correlation. Fifteen of 19 studies (79%) showed the negative correlation. From the regression lines which showed significant correlation a mean OEF at VRCO2 =0 was 0.54 +/- 0.09, which might indicate the point at the maximal dilatation of the resistance vessels. On the other hand, in hypocapnic studies only five of 18 (28%) showed apositive correlation, and the other measurements showed diffusely negative VRCO2 over the whole regions in the brain.

[A case of pineocytoma presenting with symptoms like normal pressure hydrocephalus].

A pineocytoma in an old man, whose initial symptoms resembled a normal pressure hydrocephalus, is reported. This 67-year-old man gradually became uncommunicative and difficult to walk alone in three months. Just before visiting our clinic, his family also noticed his nocturnal urinary incontinence. CT scan on admission disclosed tumor in the posterior wall of the third ventricle, and subsequent hydrocephalus. This oval, isodense tumor was homogeneously enhanced after the injection of contrast medium on CT scan. The vertebral angiography showed a mass in the pineal region with no vascular staining. Ventricular drainage, the opening pressure of which was 100 mmH2O, could not offer cytological verification of the tumor. By the infratentorial supracerebellar approach, the tumor was successfully extirpated, and the post-operative course was uneventful. The microscopic study revealed the nature of this tumor to be well compatible with that of a pineocytoma.