Xenon contrast-enhanced CT imaging of supratentorial hypoperfusion in patients with brain stem infarction.

BACKGROUND AND PURPOSE: The characteristics of hypoperfusion in the supratentorial region of patients with brain stem infarction are unclear. We investigated the relationships between the presence of hypoperfusion and the location, number, and size of the infarcts with xenon contrast-enhanced CT. METHODS: One hundred five patients with brain stem infarction detected by MR imaging underwent xenon contrast-enhanced CT to measure the regional CBF (rCBF) in the frontal, temporal, parietal, and occipital regions and in the putamen and thalamus. A decrease of more than 10% from the mean rCBF value for normal individuals was considered to indicate hypoperfusion. RESULTS: Thirty-six patients had supratentorial hypoperfusion. The mean rCBF values (measured in mL/100 g/minute) were as follows: frontal region, 36.2 +/- 5.1 (-14.8%, n = 28); parietal region, 42.3 +/- 4.7 (-19.1%, n = 29); temporal region, 41.5 +/- 2.8 (-12.6%, n = 12); and thalamus, 50.1 +/- 3.2 (-19.6%, n = 7). Supratentorial hypoperfusion was associated with pontine infarction in 33 patients (upper pons in 15, middle pons in 18, and lower pons in seven), midbrain infarction in two, and medulla infarction in one. Twenty-three patients had infarcts that were larger than 5 mm, and 11 had infarcts that were 2 to 5 mm. Only two had infarcts that were smaller than 2 mm. Seven patients each had one infarct, 13 each had two, and 16 each had three. CONCLUSION: Supratentorial hypoperfusion was associated with larger infarcts, with more infarcts, and with pontine infarction.

Clinical features of relative focal hyperfusion in patients with intracerebral hemorrhage detected by contrast-enhanced xenon CT.

BACKGROUND AND PURPOSE: The prevalence and clinical features of relative focal hyperperfusion were investigated in 165 consecutive patients with intracerebral hemorrhage. METHODS: Contrast-enhanced xenon CT was used to observe regional cerebral blood flow in all patients (86 men and 79 women ranging in age from 25 to 89 years; mean age, 66 years). The clinical data of patients with and without relative focal hyperperfusion were compared to define distinguishing characteristics. RESULTS: Relative focal hyperperfusion was observed in 24 (23.5%) of 102 patients in the acute stage but in no patient in the subacute or chronic stages. Relative focal hyperperfusion was associated significantly more often with putaminal and subcortical hemorrhage than with thalamic and cerebellar hemorrhage. We found that patients with relative focal hyperperfusion had a lower mean age than those without it; a male dominance; and a more common history of intracerebral hemorrhage. CONCLUSION: Relative focal hyperperfusion occurs in the acute stage after intracerebral hemorrhage and does not persist for more than 30 days. The most common locations are the putamen and subcortical areas. Risk factors include male sex and previous bleeding in the same area.

Technical points to improve surgical results in cases with basilar tip aneurysms.

Surgical results in 82 cases with aneurysm (61 ruptured and 21 unruptured) of the bifurcation of the basilar artery were analyzed and the causes of unfavorable outcome and its measures were discussed. Operation was performed in grade I, II, III, or IV of the Hunt and Kosnik's classification for the patients with ruptured aneurysm. Both in ruptured and unruptured cases, patient's age was not considered. As it turned out, 10 elderly (70 years old or older) cases (8 ruptured and 2 unruptured) were included in this study. Unilateral pterional approach was adopted for all but one case, and temporary clip and/or division of the hypoplastic posterior communicating artery was actively used. Surgery was completed with clipping of the aneurysm in all but six cases and overall surgical result consists of 70% of favorable outcomes. The main causes of unfavorable outcome were surgical procedures and primary brain damage due to subarachnoid hemorrhage. And the factors influenced to increase surgical technical damage to the brain were the patient's age, size of the aneurysm, and/or height of the neck from biclinoids line. The outcome of the higher grade (grade III or IV) in elderly cases was miserable, whereas it was not different from anterior circulation aneurysms in younger cases. From the result we concluded that the surgical indication for elderly cases should be limited in cases with lower grade (grade I or II) without large and/or high-positioned aneurysm. To obtain further improvement of the surgical result in younger cases, additional surgical techniques have to be considered to avoid the injury of perforating arteries from P1 and to reduce the pressure of the brain retraction which are the most important hazards for aneurysm surgery in this area.

Xenon contrast CT-CBF measurements in high-intensity foci on T2-weighted MR images in centrum semiovale of asymptomatic individuals.

BACKGROUND AND PURPOSE: White matter lesions (WMLs) on T2-weighted MR images occurring in the centrum semiovale of normal individuals are a subject of great clinical interest. We therefore investigated regional cerebral blood flow (rCBF) of the centrum semiovale among neurologically normal individuals. METHODS: One hundred thirty-five neurologically normal subjects were divided into four grades of WML on the basis of their MR images. rCBF values in the centrum semiovale were measured by xenon contrast CT methods. RESULTS: Advanced age and associated hypertension were significant risk factors for higher grade WMLs. Centrum semiovale rCBF values on the left side were 24.27 +/- 2.60 mL.100 g-1.min-1 in grade 0, 23.52 +/- 2.78 in grade I, 19.35 +/- 2.81 in grade II, 15.82 +/- 2.05 in grade III, and 11.31 +/- 2.56 in grade IV. Differences were significant between grades (P < .005 between grade 0 and grades II, III, and IV; between grade II and grades III and IV; and between grades III and IV). Patients with hypertension had lower rCBF values than those without in grades 0, I, II, and III, with significant difference in grade I (P < .005). Age-matched studies between patients 61 to 70 years old confirmed a significant difference between WML grades. CONCLUSIONS: WMLs in centrum semiovale are associated with greater age, hypertension, and reduced rCBF values.

Determination of timiperone in rat plasma by high-performance liquid chromatography with electrochemical detection.

We report a sensitive new method for the determination of timiperone in rat plasma by using high-performance liquid chromatography with electrochemical detection. The method involves extraction of plasma samples with heptane-isoamyl alcohol at pH > 8, followed by back-extraction into dilute acetic acid. Separation was accomplished by reversed-phase high-performance liquid chromatography on an ODS column with the mobile phase consisting of 0.1 M phosphate buffer (pH 3.5)-acetonitrile-methanol (65:20:15, v/v). Recovery was greater than 80%. Calibration curve was linear over the concentration range 0.5-50.0 ng/ml. The limit of quantitation of timiperone was 0.5 ng/ml plasma.

Observation of vasospasm after subarachnoid hemorrhage by magnetic resonance angiography--a preliminary study.

Serial evaluation of cerebral vasospasm following subarachnoid hemorrhage was attempted in 11 patients using magnetic resonance (MR) angiography. MR angiography demonstrated vasospasm with angiographic confirmation in three patients as a segmental narrowing or loss of flow signal, usually accompanied by decreased distal flow signal. MR angiography also showed decreased flow signal suggestive of vasospasm in another patient with clinical evidence of vasospasm but no angiographic confirmation was possible because of poor condition. MR angiography showed no vasospasm in five patients without clinical evidence of vasospasm, except in one patient with disappearance of the unilateral anterior cerebral artery signal, shown to be involvement of the clipped artery. MR angiography is a potential method for detection of vasospasm with further improvement of the technique.

Detection of intracranial aneurysms by three-dimensional time-of-flight magnetic resonance angiography.

The purpose of this study was to investigate the reliability of magnetic resonance angiography (MRA) for detection of intracranial aneurysms. Ninety-six consecutive patients who underwent both MRA using the three-dimensional time-of-flight technique (3D TOF) with the rephase/dephase subtraction method and conventional angiography were reviewed. MRA showed 22 aneurysms in 19 patients, and conventional angiography 28 aneurysms in 23 patients. The sensitivity of MRA was thus 79% for aneurysms in 83% of patients. MRA showed no aneurysm in 67 of 73 patients without aneurysms; its specificity was therefore 92%. The 6 false positive interpretations were suspected internal carotid artery aneurysms.

Incidental high-intensity foci in white matter on T2-weighted magnetic resonance imaging. Frequency and clinical significance in symptom-free adults.

The clinical significance of high-intensity foci in the white matter on magnetic resonance images of the brain was studied in 351 adults. The foci frequently occurred in the corona radiata and centrum semiovale. The frequency and extent of the foci were closely related to age and to a previous history of cerebrovascular disease. Patients without such a history but with risk factors for cerebrovascular disease tended to have these foci more frequently than those without risk factors.

Giant aneurysm of the azygos anterior cerebral artery associated with acute subdural hematoma--case report.

A ruptured giant aneurysm of the azygos anterior cerebral artery (ACA) associated with an acute subdural hematoma (SDH) occurred in a 67-year-old male with two episodes of sudden severe headache and transient loss of consciousness. Neurologically, he had mild weakness of the left lower extremity. Computed tomography showed an elliptical heterogeneous hyperdense mass in the interhemispheric fissure in front of the corpus callosum and an acute SDH on the right. Angiography disclosed a giant aneurysm (2.8 x 2.0 cm) at the distal end of the azygos ACA. Removal of the SDH and aneurysmal neck clipping achieved a good outcome. Successive small bleedings may allow the aneurysmal dome to develop adhesions to the arachnoid membrane, and the final rupture will occur into the subdural space, resulting in a SDH.

[Superior sagittal sinus thrombosis complicated with multiple aneurysms presenting as subarachnoid hemorrhage. Case report].

A 48-year-old female suffered from severe headache, vomiting, and disturbance of consciousness. On admission, she was somnolent with mild paresis of the left leg. Precontrast computed tomography (CT) scans showed a high-density area in the left sylvian fissure and the posterior horn of the left lateral ventricle. Angiographically, a right middle cerebral artery aneurysm and a basilar artery aneurysm were recognized. Furthermore, on the venous phase of bilateral carotid angiograms, superior sagittal sinus (SSS) thrombosis was recognized. Subarachnoid hemorrhage (SAH) was probably induced by rupture of a dilated vein associated with SSS thrombosis, because high-density area on CT scan and location of the aneurysms were different. The patient was initially treated conservatively. Two months later, craniotomy was performed which did not disclose any trace of hemorrhage around the aneurysms and aneurysms themselves. Postoperatively, acute brain swelling and generalized convulsion were induced. The patient became ambulatory 5 months after surgery. In SAH cases, the venous phase should be examined at least in one side of the carotid arteries. In such a SAH case induced by venous thrombosis complicated by aneurysms it is very difficult to decide the timing of surgery for aneurysms.

[Organized chronic subdural hematoma; report of two cases].

Two cases of organized chronic subdural hematoma were presented. The first case had a one-year history of disorientation and right hemiparesis. CT scan revealed a low density area with linear high density in its medial margin, suggesting chronic subdural hematoma on the left frontal convexity. Surgery was performed expecting to remove the hematoma. There was, however, only a little fluid inside with thick membranous tissue. The second case, who has Crouzon disease, presented a one-year history of pseudobulbar palsy and tetraparesis after surgery for chronic subdural hematoma and hydrocephalus. The diagnosis of organized subdural hematoma was made at the time of reoperation which was performed expecting to remove the recurrent chronic subdural hematoma. Plain CT, done after admission to our hospital, showed homogeneous low density area remaining in the bilateral frontal convexity. Infusion scan revealed marked enhancement of the medial margin of the low density area. The lesion was demonstrated as a low intensity area by T1-weighted magnetic resonance images (MRI). Marked enhancement was noted around the low intensity area after the infusion of Gd-DTPA. Although it is very hard to make a diagnosis of organized chronic subdural hematoma using only the CT scan preoperatively, combination of the CT scan and MRI with Gd-DTPA enhancement seemed to be very useful for this purpose.

Giant middle cerebral artery aneurysm with parent artery occlusion--case report.

A 54-year-old female was admitted with consciousness disturbance and right hemiparesis. Computed tomographic (CT) scans and angiograms revealed diffuse subarachnoid hemorrhage, a partially thrombosed, giant middle cerebral artery aneurysm (5 x 5 x 4 cm), and occlusion of the parent artery at the aneurysm site. Despite conservative treatment, a generalized convulsion occurred. Emergency CT scans revealed irregular enlargement of the left temporal high-density mass and severe mass effect due to cerebral infarction. Barbiturate coma therapy was administered, but she did not recover and died 9 days after admission. Only two cases of ruptured aneurysm with simultaneous occlusion of the major cerebral vessels have been reported, both with poor outcome. In this case, the mechanism of parent artery occlusion is unclear, but thrombus protrusion from the giant aneurysm into the parent artery may have been involved.

[Ruptured cerebral aneurysm followed by primary intracranial malignant lymphoma: case report].

Reported herein is a case of ruptured anterior cerebral aneurysm followed by primary intracranial malignant lymphoma. A 73-year-old female was admitted to our hospital on October 20, 1986, with a severe subarachnoid hemorrhage. Microsurgery was performed immediately on the day of admission because cerebral angiography revealed bilateral distal anterior cerebral artery aneurysms. Consciousness gradually deteriorated due to cerebral vasospasm from the 3rd day following surgery. To protect the brain, corticosteroid (methylprednisolone 1500 mg, dexamethasone 252 mg) was administered for 26 days after surgery. In spite of treatment, in March 1987 neurological examination revealed akinetic mutism, but CT scan did not reveal any evidence of tumor. CT scan performed on May 2, 1987, revealed a mass lesion in the left frontotemporal lobes and left basal ganglia. Histological diagnosis of malignant lymphoma (diffuse, large-cell type) was obtained by stereotactic biopsy. Radiotherapy (41 Gy of 60Co) was carried out. The CT scan performed on August 26, 1987 revealed that the abnormal enhanced lesion had disappeared. However, neurological findings had not remarkably improved. The patient died of renal failure in February 1988, but tumor recurrence had not been noted in CT scans. Autopsy could not be performed. Whole body CT scan and 67Gd scintigram did not reveal any other tumors except in the brain. Ruptured cerebral aneurysm followed by primary intracranial malignant lymphoma is very rarely reported. In such cases, which have unusual clinical courses and CT findings, we recommend stereotactic biopsy to treat this kind of radiosensitive tumor. The connection between malignant lymphoma and immunosuppression has been considered.(ABSTRACT TRUNCATED AT 250 WORDS)

Complete remission of recurrent glioblastoma multiforme following local infusions of lymphokine activated killer cells. Case report.

We report the case of a 26-year-old man in whom glioblastoma multiforme had recurred six months following a subtotal resection. Despite radiotherapy and a course of interferon beta and ACNU, the tumour increased in size (to 3 cm) and there was neurological deterioration. Treatment was then initiated with LAK cells, together with ACNU and interferon beta. After three courses of LAK cells, tumour size was markedly reduced, and at about six months the tumour had nearly disappeared on computed tomographic (CT) scans. At one year, and after nine courses of LAK cell therapy (total dose of 2.7 x 10(9) cells) infused via an Ommaya reservoir and supplemented by ACNU and interferon beta, the tumour has disappeared and the patient is considered to be in complete remission since 6 months. This marked response is thought to be due chiefly to LAK cell therapy. The relatively low dose administered was well-tolerated.

Primary internal ophthalmoplegia due to head injury.

Six cases of internal ophthalmoplegia due to direct head injury are presented. All six patients had a dilated, nonreactive pupil. Four had no extraocular palsies or ptosis and two had partial extraocular palsies or ptosis. Disturbance of consciousness was absent or very mild, and all patients fully recovered within 1 to 7 days after the traumatic event. No patient had a history that suggested a cause for oculomotor nerve palsy, and emergency CTscans showed no mass lesions. The internal ophthalmoplegia was recognized immediately after trauma. Although minimal oculomotor nerve palsies due to unruptured intracranial aneurysms have been described, none of our patients complained of periorbital or retroorbital pain either before or after the trauma, which rules out intracranial aneurysms as the cause of the internal ophthalmoplegia. Therefore, we concluded that the internal ophthalmoplegia was due to direct head injury. The pathophysiological mechanism of the internal ophthalmoplegia appeared to be slight injury of the pupillomotor fibres on the ventromedial surface of the third nerve at the posterior petroclinoid ligament, which acted as the fulcrum due to the downward displacement of the brainstem at the time of impact.

Intraoperative monitoring of the motor function: experimental and clinical study.

Manipulation of the lesions adjacent to the primary motor area or the motor pathway is troublesome for neurosurgeons because they lack an effective method to determine the primary motor area or to monitor motor function in the operative room. It will be of great value to establish a monitoring method of the corticospinal tract under general anaesthesia. We recorded the motor evoked potential (MEP) from direct motor cortex stimulation in cats and showed that it derives almost purely from the corticospinal tract. Then we used this technique during the operation of the resection of tumours near the primary motor area or the motor pathway. 1. Experimental study: Twenty adult cats were used in this study. Recording electrodes were flexible bipolar catheter electrodes inserted into the spinal epidural space. Stimulating electrodes were silver ball electrode on the cortex (anode) and needle electrode in the temporal muscle (cathode). Stimulation of 4-24 V, 5-10 Hz and 0.2 msec in duration were done and evoked potentials signals were averaged 60 to 512 times. MEP with multiple peaks was obtained that had a 112 msec conduction velocity in the spinal cord. We found the same signals from the stimulation of ipsilateral cerebral peduncle. Radiofrequency lesioning of ipsilateral cerebral peduncle produced a loss of MEP. These results show that MEP derives from the corticospinal tract. Significant wave form change, with components of short latency, was noted by the excessively intense stimuli. We supposed that superimposition of the signals from the extrapyramidal pathways, excited in the brain stem, results in this change.(ABSTRACT TRUNCATED AT 250 WORDS)