Masahiro Yonekura

Small Unruptured Intracranial Aneurysm Verification Study: SUAVe Study, Japan

Background and Purpose— The natural history and optimal management of incidentally found small unruptured aneurysms <5 mm in size remain unclear. A prospective study was conducted to determine the optimal management for incidentally found small unruptured aneurysms. Methods— From September 2000 to January, 2004, 540 aneurysms (446 patients) were registered. Four hundred forty-eight unruptured aneurysms <5 mm in size (374 patients) have been followed up for a mean of 41.0 months (1306.5 person-years) to date. We calculated the average annual rupture rate of small unruptured aneurysms and also investigated risk factors that contribute to rupture and enlargement of these aneurysms. Results— The average annual risks of rupture associated with small unruptured aneurysms were 0.54% overall, 0.34% for single aneurysms, and 0.95% for multiple aneurysms. Patient <50 years of age (P=0.046; hazard ratio, 5.23; 95% CI, 1.03 to 26.52), aneurysm diameter of ≥4.0 mm (P=0.023; hazard ratio, 5.86; 95% CI, 1.27 to 26.95), hypertension (P=0.023; hazard ratio, 7.93; 95% CI, 1.33 to 47.42), and aneurysm multiplicity (P=0.0048; hazard ratio, 4.87; 95% CI, 1.62 to 14.65) were found to be significant predictive factors for rupture of small aneurysms. Conclusions— The annual rupture rate associated with small unruptured aneurysms is quite low. Careful attention should be paid to the treatment indications for single-type unruptured aneurysms <5 mm. If the patient is <50 years of age, has hypertension, and multiple aneurysms with diameters of ≥4 mm, treatment should be considered to prevent future aneurysmal rupture.

Incidence and Outcome of Multiple Intracranial Aneurysms in a Defined Population

Background and Purpose— Proportions of patients with single and multiple aneurysms among patients suffering from subarachnoid hemorrhage (SAH) are not well established. We evaluated these proportions and the differences in outcome between SAH patients with a single aneurysm and those with multiple aneurysms in a defined population. Methods— Between 1989 and 1998, 2037 patients (age, 20 to 89 years) with ruptured intracranial aneurysm were treated in 11 hospitals in Nagasaki Prefecture. Multiple aneurysms were found in 361 of these patients. Age- and sex-specific incidences of ruptured aneurysm per 100 000 people were calculated. Results— For both single and multiple aneurysms, the incidences were significantly higher in women than in men 60 to 69 and 70 to 79 years of age. In every age category except 80 to 89 years, the frequency of multiple aneurysms was higher in women than in men. The overall frequency of multiple aneurysms was 20.2% in women, which was significantly higher than the 12.4% in men (P <0.0001). In patients 70 to 89 years of age, outcome was significantly worse (in terms of surgical complications) in patients with multiple aneurysms (12.1%) than in patients with a single aneurysm (6.0%). Conclusions— Among all patients with SAH, women ≥50 years of age outnumber other age and sex categories. Female sex itself is also associated with an increased rate of multiple aneurysms among SAH patients. Among the elderly ≥70 years of age, prognosis is less favorable for SAH patients with multiple aneurysms than for those with a single aneurysm.

Effect of Acetazolamide on Regional Cerebral Oxygen Saturation and Regional Cerebral Blood Flow

BACKGROUND AND PURPOSE To verify whether the monitoring of regional cerebral oxygen saturation (rSO2) with transcranial near-infrared spectroscopy would successfully reflect changes in intracranial hemodynamics but not changes in extracranial compartment, we measured rSO2 and regional cerebral blood flow (rCBF) simultaneously in seven patients with cerebral ischemia and five normal volunteers before and after acetazolamide administration. SUMMARY OF REPORT The baseline values of rSO2 and rCBF were 64.2 +/- 5.6% and 53.9 +/- 11.1 mL/100 g per minute, respectively. rCBF increased by 44.4 +/- 23.3% and rSO2 significantly increased to 69.6 +/- 5.6% after acetazolamide administration. Bilateral simultaneous measurement of rSO2 indicated a tendency that the larger the delta rSO2, the greater the delta%rCBF. The relationship between rSO2 level and rCBF value fit significantly on the theoretical curve calculated from Ficks equation. CONCLUSIONS It is suggested that monitoring of rSO2 with INVOS-3100 could be a useful indicator in the evaluation of intracranial hemodynamic changes.

Early intervention to promote oral feeding in patients with intracerebral hemorrhage: a retrospective cohort study

BackgroundStroke is a major cause of dysphagia, but little is known about when and how dysphagic patients should be fed and treated after an acute stroke. The purpose of this study is to establish the feasibility, risks and clinical outcomes of early intensive oral care and a new speech and language therapist/nurse led structured policy for oral feeding in patients with an acute intracerebral hemorrhage (ICH).MethodsA total of 219 patients with spontaneous ICH who were admitted to our institution from 2004 to 2007 were retrospectively analyzed. An early intervention program for oral feeding, which consisted of intensive oral care and early behavioral interventions, was introduced from April 2005 and fully operational by January 2006. Outcomes were compared between an early intervention group of 129 patients recruited after January 2006 and a historical control group of 90 patients recruited between January 2004 and March 2005. A logistic regression technique was used to adjust for baseline differences between the groups. To analyze time to attain oral feeding, the Kaplan-Meier method and Cox proportional hazard model were used.ResultsThe proportion of patients who could tolerate oral feeding was significantly higher in the early intervention group compared with the control group (112/129 (86.8%) vs. 61/90 (67.8%); odds ratio 3.13, 95% CI, 1.59-6.15; P < 0.001). After adjusting for baseline imbalances, the odds ratio was 4.42 (95% CI, 1.81-10.8; P = 0.001). The incidence of chest infection was lower in the early intervention group compared with the control group (27/129 (20.9%) vs. 32/90 (35.6%); odds ratio 0.48, 95% CI, 0.26-0.88; P = 0.016). A log-rank test found a significant difference in nutritional supplementation-free survival between the two groups (hazard ratio 1.94, 95% CI, 1.46-2.71; P < 0.001).ConclusionsOur data suggest that the techniques can be used safely and possibly with enough benefit to justify a randomized controlled trial. Further investigation is needed to solve the eating problems that are associated with patients recovering from a severe stroke.

Congenital cavernous angioma of the temporal bone: case report

BACKGROUND Congenital cavernous angioma is a very rare tumor that occurs in young adolescents. We describe a rare case of congenital cavernous angioma of the temporal bone in a neonate. Ultrasonography (US) and dynamic magnetic resonance imaging (MRI) were helpful in its diagnosis. CASE DESCRIPTION US and MRI of the fetus in the 32nd week of gestation revealed a large extra-axial tumor with intra- and extracranial extension. After the birth, US and dynamic MRI studies were performed in addition to conventional CT and MRI. These findings were compatible with cavernous angioma. The mass was totally removed on the fourth day of life and was found at surgery to originate from the skull. Histopathological diagnosis was cavernous angioma. The usefulness of US and dynamic MRI are also discussed. CONCLUSION US and dynamic MRI are useful, less invasive techniques for diagnosing this rare type of tumor. They provide useful information to differentiate calvarial mass lesions in neonates.

Factors affecting rapid growth of unruptured cerebral aneurysms during the acute stage of subarachnoid hemorrhage.

Abstract Background and purpose: Several unruptured cerebral aneurysms have been reported to grow and rupture. To determine which factors affect the growth of these aneurysms during the acute stage of subarachnoid hemorrhage (SAH), a retrospective review was performed. Methods: Between January 2000 and January 2003, 130 patients with angiographically proven ruptured cerebral aneurysms were treated at our institution. Of these patients, 32 also had simultaneous unruptured aneurysms, and the total number of the unruptured aneurysms was 40, including two neck remnants which had remained since the past clipping. Seventeen patients had 17 unruptured aneurysms and two neck remnants. The unruptured aneurysms were not treated during the acute stage of SAH but had received a complete short term follow-up. Results: The rapid growth of one unruptured aneurysm and two neck remnants was confirmed by a second angiogram performed on average40 days after the first angiogram. Several candidate factors responsible for the growth of aneurysm were selected, and the results of a statistical analysis indicate that a systolic blood pressure above 200 mmHg during the acute stage of SAH and vasospasm, confirmed by transcranial Doppler ultrasound (TCD) or neurological examination, and neck remnants, are risk factors that affect the growth. Conclusions: Short term follow-up angiography is thus important for patients with untreated unruptured cerebral aneurysms after the acute stage of SAH.

Dolichoectasic Anterior Cerebral Artery and Hemodynamics

Dolichoectasia of the intracranial arteries is a rare condition, and the vertebrobasilar system and the internal carotid artery are the most commonly involved structures. We report a rare case of idiopathic dolichoectasia of the anterior cerebral artery in a 22-year-old female. The patient caused an automobile accident and was brought to our hospital in an ambulance. A computed tomography scan and magnetic resonance imaging revealed no fresh lesions, but showed a prominent serpentine structure with calcification and flow void in the region of the interhemispheric fissure, which was suspicious for arteriovenous malformation or arteriovenous fistula. Cerebral angiography demonstrated extensive dilatation of the anterior cerebral artery, but no evidence of arteriovenous malformation or arteriovenous fistula. Single photon emission computed tomography revealed hypoperfusion of the right frontal lobe at rest. Electroencephalography showed no epileptic discharge. The patients course was uneventful, and she was discharged with no neurologic deficit. There are few reports of hemodynamic changes in cases of dolichoectasia. In the diagnosis of cerebral dolichoectasia, cerebral hemodynamics should be examined carefully in addition to evaluating vascular disease by angiography.

De novo ruptured aneurysm at the site of anastomosis after superficial temporal artery-middle cerebral artery anastomosis--case report and literature review.

Extracranial (EC)–intracranial (IC) bypass surgery, most comonly superficial temporal artery (STA)–middle cerebral artery MCA) anastomosis, has been established as a surgical procedure or treating major cerebral artery occlusive disease, and the main bject of this procedure is to reduce future ischemic events [1,2]. ignificant alterations in blood-flow patterns and hypertrophic hanges in the caliber of both the EC artery and adjacent segments f the cortical arteries are common after EC-IC bypass. However, ostoperative aneurysm formation at the anastomotic site or in its lose proximity is a relatively rare complication of this procedure 1–11]. We describe a rare case of intracerebral hemorrhage from a uptured aneurysm at the anastomotic site 2 years after STA–MCA nastomosis.

Olefin hydrogenations with hydrido(phosphonite)cobalt(I) under photoirradiation and EHMO calculations for the phosphonite photodissociation process

Abstract Pyrex-filtered photoirradiation of hydrido(phosphonite)cobalt(I) [CoH{PPh(OEt)2}4] (CoHL4) brought about catalytic olefin hydrogenations under a dihydrogen pressure of 6 kg/cm2, and a photogenerated coordinatively unsaturated transient species CoHL3 was presumed to be the key-role-playing intermediate in the catalytic reaction cycles. EHMO calculations for the Cs-symmetric model complex [CoH{PH(OH)2}4] determined that photodissociation of a phosphonite ligand (L) proceeded in the equatorial direction, leading to the olefin incorporation on the equatorial site in the course of [CoH(olefin)L3] intermediate formation.