Toshihide Toriyama

Transradial approach for selective cerebral angiography: technical note.

Abstract Selective cerebral angiography is currently being performed using transfemoral and transbrachial approaches. However, these techniques require patients to tolerate a prolonged focal compression and sometimes cause serious complications such as pulmonary embolism. The authors describe a technique of transradial approach as a safer selective cerebral angiography. Between July 1997 and November 1998, 70 patients underwent selective cerebral angiography with a transradial approach using a 4-F catheter. The collateral blood supply to the hand from the ulnar artery was confirmed using Allen’s test prior to the procedure. To prevent the mechanical spasm of the radial artery, an arterial introducer 20 cm long was used. The radial artery was successfully punctured and cannulated in all patients. Selective catheterization of the intended vessels was obtained In over 98% of the carotid angiography and over 95% of the vertebral angiography. No major vascular complications such as cerebral infarction, upper limb ischemia, significant local hematoma or pseudoaneurysm were experienced. The transradial approach is a less invasive and safer technique for selective cerebral angiography, and could be an alternative to transfemoral and transbrachial approaches. [Neurol Res 2000; 22: 605-608]

Surgical approaches to the anterior communicating artery aneurysm and their results.

In the past 12 years, 102 cases of anterior communicating artery aneurysm have been operated upon in our institution. Two basic microsurgical approaches (pterional and interhemispheric) were used. The combined pterional and interhemispheric approach was performed in a few cases. The rational for each surgical approach is discussed in relation to anatomical factors such as the height of the aneurysm neck, the side of dominance of A1, the relationship between the bilateral proximal parts of A2s, and the projection of the aneurysm. The final outcome was correlated to the preoperative clinical grading and timing of surgery. The overall results were as follows; 82.4% good, 5.9% fair, 4.9% poor, and 6.8% mortality rate. The operative results for pterional and interhemispheric approach were comparable with each other. In the combined approach, we got poorer results which could be related to excessive brain retraction and unfavourable clinical grading.

Intraoperative Regional and Functional Thermography during Resection of Cerebral Arteriovenous Malformation

We present the first use of intraoperative thermographical imaging for the surgical resection of a cerebral arteriovenous malformation. For obtaining intraoperative regional and functional thermographical images, a real-time mode infrared camera was installed to an operating microscope with an exclusively developed attachment device. Changes of the surface temperature of the cortical draining vein and the surrounding cortical surface were observed intraoperatively before and after the occlusion of the main feeder. Intraoperative functional thermography with cold physiological saline solution demonstrated a change in the heat clearance of the draining vein after complete obliteration of the feeder.

A classification of juxta-dural ring aneurysms with reference to surgical anatomy.

We report a subgroup of internal carotid artery (ICA) aneurysms located near the carotid ring which we call juxtadural ring aneurysms. These aneurysms are classified into three types: paraclinoid intradural, carotid cave and infraclinoid extradural aneurysms. The paraclinoid intradural aneurysms arise from the ICA distal to the origin of the ophthalmic artery and are close to the dural ring, which may include some so-called carotid-ophthalmic aneurysms. The carotid cave aneurysms are located in the carotid cave which is seated in the infraclinoid carotid groove and proximal to the origin of the ophthalmic artery. They are located at the angiographical genu and in the intradural space anatomically. The infraclinoid extradural aneurysms are located close to the dural ring extradurally in the infraclinoid carotid groove sinus, a peripheral venous space of the cavernous sinus. The infraclinoid extradural aneurysms should be differentiated from aneurysms in the cavernous sinus, because they are located in the infraclinoid carotid groove sinus.

Functional image of dynamic computed tomography in diagnostic and prognostic evaluation of ischemic stroke within the first 6 hours.

Background and Purpose It is important to make a diagnosis before a low-density area appears on computed tomography for appropriate management of acute ischemic stroke. We report the diagnostic and prognostic usefulness of functional image of dynamic computed tomography for acute ischemic stroke. Methods Forty-seven patients with ischemic strokes within 6 hours of ictus underwent dynamic computed tomography in which functional images were obtained. These findings were compared with angiographic findings, follow-up computed tomography, and clinical outcome. Results The functional images were categorized into three groups: (1) cortical type: abnormalities on time to peak image and/or corrected mean transit time image involving mainly cortical structures (29 cases); (2) noncortical type: abnormalities on either or both images limited to noncortical structures (7 cases); and (3) normal type: no abnormalities on both images (11 cases). Cortical type as a diagnostic test for arterial trunk occlusion had a good sensitivity (100%), specificity (95%), and accuracy (98%). Infarction volume on follow-up computed tomography correlated with extension of prolonged time-to-peak area (r=.80, P < .01) and that of prolonged corrected mean transit time area (r=.81, P < .01). Cortical type was associated with significantly unfavorable outcome (P < .01). Conclusions Functional image of dynamic computed tomography findings predicted arterial trunk occlusion, infarction volume, and clinical outcome. Therefore, this technique would be useful not only for indicating definitive angiography and subsequent therapy but for evaluating the effectiveness of surgical or medical recanalization.

Uncommon course for a vertebral artery dissection: Rupture, occlusion and recanalization

Intracranial arterial dissections of the vertebrobasilar system are recognized as a cause of stroke. Although the pathogenic mechanism underlying this phenomenon is unknown, in some cases the stroke originates from subarachnoid hemorrhage, while in others ischemia is the cause. In cases where hemorrhage occurs, occlusion of the lesion is effective in reducing the risk of re-bleeding. However, deciding on treatment is difficult in uncommon cases in which occlusion occurs immediately after hemorrhage. Intracranial arterial dissections of the vertebrobasilar system often present as subarachnoid hemorrhage, and the most appropriate surgical treatment remains controversial. In this report, we describe a rare case of vertebral artery dissection in which occlusion occurred immediately after subarachnoid hemorrhage. Serial angiography revealed spontaneous recanalization of the right vertebral artery dissection, as well as enlargement. The progressive angiographic changes of the ruptured vertebral artery dissection and the endovascular treatment of such arterial dissections are discussed.

Characterization of migraineurs presenting interictal widespread pressure hyperalgesia identified using a tender point count: a cross-sectional study

BackgroundMigraineurs exhibit pain hypersensitivity throughout the body during and between migraine headaches. Migraine is classified as a central sensitivity syndrome, typified by fibromyalgia showing widespread pressure hyperalgesia determined by a tender point. This study was performed to examine whether: 1) there is a subgroup of episodic migraineurs with widespread pressure hyperalgesia during and between attacks; 2) if such a subgroup exists, what is the prevalence and what is the difference between groups with interictal widespread hyperalgesia and acute allodynia regarding the demographic and clinical characteristics of migraine.MethodsThis was a cross-sectional study. A total of 176 consecutive episodic migraineurs and 132 age- and sex-matched controls were recruited. The presence of widespread pressure hyperalgesia was investigated using manual tender point survey. To classify a subject’s response as widespread pressure hyperalgesia, the cutoff value for responders was defined as the positive tender point count below which 95% of controls responded.ResultsBased on the number of positive tender points in controls, the cutoff value of tender point count for pressure hyperalgesia responders was 7. Of the 176 subjects, interictal widespread pressure hyperalgesia and acute allodynia were observed in 74 (42%) and 115 (65.3%) patients, respectively. Univariate analysis indicated that risk factors associated with interictal widespread pressure hyperalgesia were female gender, younger age at migraine onset, higher frequency of migraine attacks, severe headache impact, cutaneous allodynia and depression. Multivariate logistic regression analysis confirmed that independent risk factors associated with interictal widespread pressure hyperalgesia were female gender, higher frequency of migraine attack and younger age at onset.ConclusionInterictal widespread pressure hyperalgesia was common (42%) in the episodic migraineurs and was associated with younger age at onset, female gender, and higher frequency of headache, but not duration of migraine illness. Presence of interictal widespread pressure hyperalgesia is assumed to be an indicator of genetic susceptibility to migraine attacks. We expect that a tender point count, as an alternative to quantitative sensory testing, will become useful as a diagnostic indicator of interictal hyperalgesia in migraineurs to predict susceptibility to migraine attacks and to permit tailored treatment.

En Bloc removal of soft tumors within the brain parenchyma using spoon retractors: traction-dissection method: Technical note

BACKGROUND En bloc removal of soft tumors within the brain parenchyma has rarely been performed. We describe a safe technique for en bloc removal of the tumors using a spoon retractor, which enables retraction while holding the soft mass upward. METHODS Dissection of a tumor mass is performed under traction of the surrounding brain tissue by retracting the mass using a spoon retractor. A dissection plane is first established in a relatively safe area, not opposite the critical area, after a corticotomy. The dissection plane is then extended toward the critical side. After circumferential dissection of the tumor mass, the dissection is continued spirally into deeper regions by retracting and holding the mass upward using a spoon retractor. In this way, the tumor is removed en bloc. CONCLUSIONS The traction-dissection method using spoon retractors is useful in performing en bloc removal of soft tumors within the brain parenchyma less invasively and provides an appropriate operating field even at depth, reducing intraoperative bleeding, and in vascular rich tumors, possibly preventing tumor seeding in cases of malignant tumors.

Angiographic differentiation of carotid cave aneurysms from ventral paraclinoid carotid aneurysms of Nutik type.

Although it appears that carotid cave and ventral paraclinoid carotid aneurysms are different types of internal carotid artery (ICA) aneurysms, it can be difficult to differentiate the two on the basis of angiograms, because their locations are very close. The purpose of this study was to review the angiographic findings in 21 cases with carotid cave aneurysms and 7 cases with ventral paraclinoid carotid aneurysms of less than 15 mm in diameter (Nutik aneurysm) operated upon in our unit during the last 14 years, and to discuss the difference between the two groups. The results showed that in the anteroposterior view of the angiogram, all carotid cave aneurysms projected medially in semicircular, or berry shape, while only slight medial projection was noted in 3 cases with Nutik aneurysm, the remainder being super-imposed on the ICA. In the lateral view of the angiogram, we found that in 6 of the 7 Nutik aneurysms there was a space between the axilla (area inside the genu of the ICA) and the anterior or anteroinferior wall of the aneurysm. This space was absent in all carotid cave aneurysms since these aneurysms projected inferoposteriorly from the genu of the ICA. It is concluded that predominant medial projection in the anteroposterior view and absence of space in the lateral view are two characteristic features of carotid cave aneurysms which can be used to differentiate them from most Nutik aneurysms.