The adjectives dorsal and ventral, are traditionally never put on the intracranial structures, the intracranial arteries in particular, except for the thalamic and hypothalamic nuclei. The thalamus which originally meant a room or space was used by Galen to indicate the anterior portion of the lateral ventricle from where animal spirit flew into the optic nerve. He named what we now call thalamus“glutia or nates (buttocks)”because of the morphological similarity. In the medieval era, the lateral ventricles were found to have nothing to do with the optic nerves and the name “thalamus” was then given to the nates of Galen. This is the reason why the superior or superficial part of the thalamus is expressed as “dorsal” and the inferior part is referred to as “ventral”. This naming is not applicable to the intracranial arteries. Kobayashi and his collaborators coined the term “internal carotid (IC) dorsal wall aneurysms” or IC-dorsal aneurysms which actually were located on the anterior wall of IC; subsequently Nutik called aneurysms arising from the posterior wall of IC nearby the anterior clinoid process “ventral paraclinoid aneurysms”. These names are very confusing. They also coined the term “carotid cave aneurysms”. The carotid cave or the clinoid space is a space between the dural ring (distal ring) and the proximal ring or more exactly a space surrounding the genu (C3) portion of the internal carotid, covered superiorly by the superficial layer of the dura of the anterior clinoid process and inferiorly by the deep layer of the anterior clinoid dura and its continuation “carotico-oculomotor” membrane. Intracranial aneurysms are classified according to the location where their necks arise, such as IC-posterior communicating aneurysms, IC-superior hypophyseal aneurysms etc. Most of carotid cave aneurysms are arising from the C3 portion of IC and growing into the carotid cave, therefore they should be called “aneurysms of the IC C3” or “clinoid segment aneurysms”. If we want to stress aneurysmal neck being located nearby the dural ring (distal ring) so that clipping of the aneurysms needs removal of the anterior clinoid process, incision of the dural ring or unroofing of the optic canal, such aneurysms may be called “juxta-clinoid aneurysms” including IC-C3 aneurysms, IC-ophthalmic aneurysms, IC-superior hypophyseal aneurysms, IC-C2 anterior wall aneurysms, IC-C2 posterior wall aneurysms and some aneurysms arising from the intracavernous (C4) portion of IC. (Original angiographical naming of sections of IC by Fischer (1938) is modified anatomically by Fukushima (1995) as follows: C1 IC bifurcation to the posterior communicating artery; C2, the posterior communicating artery to the dural ring; C3, the dural ring to the carotico-oculomotor membrane; C4, the carotico-oculomotor membrance to the meningohypophyseal trunk; C5, the meningohypophyseal trunk to the foramen lacerum)

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An increasing number of older patients are receiving neurosurgical treatment. To investigate the clinical features of elderly patients who had aneurysmal subarachnoid hemorrhage (SAH), we reviewed 40 consecutive cases aged 70 years or older operated on for ruptured cerebral aneurysms.
Ninety-five percent of the patients were admitted within 3 days after SAH, and 60%were operated on in the acute stage.
Both the Hunt & Kosnik grade on admission and Glasgow Outcome Scale (GOS) at discharge were significantly worse in elderly patients than in younger ones. In Grade I-III, there was no significant difference in GOS between the elderly and the young group. But in the Grade IV patients, all elderly ones showed poor clinical outcome (severe disability, persistant vegetative state, or death), whereas 45%of the young ones showed a good outcome (good recovery or moderate disability). The mortality rate of patients operated on in the acute stage was significantly higher than that in delayed surgery (42% vs. 8%), but the overall outcome showed no significant difference between the two groups. In the elderly group, there were fewer anterior communicating artery aneurysms and more vertebrobasilar artery aneurysms than in the young group (n.s.).
As for the relation between the site of aneurysm and the clinical outcome, the elderly patients with distal anterior cerebral artery aneurysm showed a worse outcome than the young ones.
The primary causes of poor outcome of elderly patients were primary brain damage due to the initial SAH and vasospasm, whereas in the young group the latter was the main factor. Primary causes of death included general complications as well as the initial bleeding and vasospasm.
In aneurysmal surgery of elderly patients, deterioration in the central nervous system as well as in other organs should be considered more.

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We analyzed 49 consecutive poor-grade patients with subarachnoid hemorrhage (SAH) treated over 5 years from 1990 to 1994. The preoperative Hunt & Kosnik (H & K) Grade was IV or V for all 49 after introduction of Ca²⁺ antagonist.
The H & K Grade IV patients were sub-classified in IVa and IVb, depending on whether consciousness was present or not. Eight patients were classified in Grade IV a, 16 patients were classified in Grade IVb, and 25 patients were classified in Grade V. Twenty-six patients had direct aneurysmal surgery within 48 hours. Their condition was evaluated on the Glasgow Outcome Scale (GOS) at 3 months after operation with the following results: Good recovery (GR) in 6, moderate disability (MD) in 3, severe disability (SD) in 7, persistent vegetative state (PVS) in 6 and death (D) in 27. The 23 inoperable patients and 3 patients who had minor operations all died.
Primary brain damage (23/49, 45%) was the major poor prognostic factor. Rebleeding (21/49, 43%) was the second important factor (GR, 4; MD, 3; SD, 1; PVS, 0; D, 13). Three patients (12%) had permanent neurological deficits but there were no deaths due to vasospasm. The operative procedures adversely affected 2 patients (delayed intracerebral hematoma in venous origin) of poor prognosis. Twelve patients aged more than 70 years old also had a poor prognosis (SD, 2; PVS, 3; D, 7). In Grade IVb, 2 patients of intracerebral hematoma and 1 patient of hydrocephalus had a good prognosis when immediate decompression was performed. No patients died due to vasospasm, but the rate of patients with poor prognosis was still high (82%of over all patients and 65%of clipping patients) in poor-grade patients.

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Rebleeding was analyzed in 396 patients admitted to our institute within 6 hours of aneurysmal subarachnoid hemorrhage (SAH) attack during the 14-year period from 1981 to 1994. Rebleeding occurred in 51 of these cases. The mean age was 61 years and the female/male ratio was 1.3: 1. The site of the ruptured aneurysm was most often located in the anterior communicating arteries. Thirty-five patients rebleed within 6 hours after the initial attack, accounting for 69%of all rebleeding cases.
Rebleeding occurred in 20 cases during cerebral angiography, and in 24 cases prior to angiography. Eighty-five percent of rebleeding occurred at a systolic blood pressure over 140mmHg. Mortality in the rebleeding cases was 71%and the neurological grade worsened after rebleeding. Rebleeding is thus an important factor influencing the prognosis of SAH.
The results of this analysis suggest that rebleeding can be prevented by lowering blood pressure before surgery and performing emergency surgery as soon as possible after the diagnosis of SAH.

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We report 3 cases of ruptured basilar artery aneurysms associated with adult moyamoya disease and review an additional 29 cases of basilar artery aneurysms associated with moyamoya disease in the literature.
A 37-year-old woman with aneurysms at the basilar bifurcation and the junction of the left superior cerebellar and basilar artery was successfully treated with intentionally delayed aneurysm obliteration by the subtemporal approach on Day 16 after bleeding. Two other cases died after rerupture of basilar artery aneurysms. A 52-year-old woman developed rerupture on Day 11 followed by a fatal rupture on Day 24, and a 51-year-old man developed rerupture on Day 12 followed by a fatal rupture 11 years later.
Twenty-one (66%) of the 32 cases we reviewed bled from basilar artery aneurysms and 11 cases (34%) had multiple saccular aneurysms. Of 12 non-surgical cases, 5 patients (42%) died of aneurysm rerupture or angiospasm, 5 (56%) of 9 cases with aneurysmal bleeding developed rerupture. Of the 20 cases treated by open surgery (17 cases) or endovascular surgery (3 cases), 12 patients (60%) had a good outcome, 4 patients (20%) died and 2 patients each developed a moderate or severe disability. All these disabilities were caused by intracerebral hemorrhage itself.
Thus, basilar artery aneurysms associated with moyamoya disease should be treated surgically. However, the procedures should be carefully selected; early surgery for aneurysm obliteration can be applied to patients with a good preoperative grade (Grade 1 or 2), delayed surgery to patients with a poor preoperative grade (higher than Grade 2), and endovascular surgery to patients with nonruptured large aneurysm or poor risk.

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We analyzed clinical characteristics and surgical results in 44 patients aged 70 years or more with ruptured intracranial aneurysms operated on within 72 hours of hemorrhage. In comparison with a non-aged group of 264 patients aged less than 70 years (126 men and 138 women), the aged group (6 men and 36 women) showed a distinct female preponderance. The most common parent artery of ruptured aneurysm was the internal carotid artery in the aged group, while it was the anterior cerebral artery in the non-aged group. There. was no significant difference in the preoperative clinical grades (Hunt & Kosnik classification) between the two groups.
Although delayed ischemic neurological deficit (DIND) appeared in both groups at almost the same frequencies, 32% and 34% for the aged and non-aged group, respectively, the incidence of permanent DIND was higher in the aged group (50%) than in the non-aged group (36%). The comparative studies on surgical results in each clinical grade revealed that outcomes of Grade IV patients were extremely poorer in the aged group (92% poor outcome) than those in the non-aged group (58% poor outcome, p=0.02). Although Grade III patients in the aged group also showed poorer outcomes, it did not reach statistical significance. Overall outcomes in a subgroup of patients aged 70-74 were almost the same as those in the non-aged group. Thus indications for early aneurysm surgery in aged patients, when their ages are under 75 and clinical grades below G III, are determined with the same standards as in non-aged patients. Among the factors accounting for poor outcome of each patient, the incidence of primary brain damage was higher in the aged group (53%) than that in the non-aged group (43%). These results indicate that the major cause of poor outcomes of aged patients is a poor recovery from brain damage due to either primary hemorrhage or symptomatic vasospasm.

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We studied Xenon-CT cerebral blood flow (CBF) after local thrombolysis with urokinase. Nine patients (5 males and 4 females) were analyzed. Occluded arteries were middle cerebral artery in 7 cases, internal cerebral artery in 1 case and basilar artery in 1 case. CBF decreased not only in the infarcted area but also in a wide area of the affected hemisphere. CBF of the non-affected hemisphere also decreased although the degree was less than on the affected side. CBF of the chronic phase in 4 cases tended to increase in the non-affected hemisphere, but it decreased in the affected hemisphere. From the symptomatic viewpoint, neurological deficits such as hemiparesis, aphasia, consciousness disturbance remained in 8 cases. Many obstacles must be resolved for the functional recovery of such patients.

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We analyze the change of neurological symptoms and cerebral blood flow (CBF) after aspiration of hypertensive cerebral hemorrhage in the chronic phase in 9 cases. In 7 cases, the paresis improved moderately 4.7 days after the operation. In 5 cases, aphasia improved markedly 4 days after the operation, and the patients became able to converse. However, CBF did not change so much even after the aspiration. The pre- and post-operative hemispheric CBF of the affected side were 38.4, 38.3 ml/100g/min in the basal ganglia level and 38.5, 34.2 ml/100g/min in the lateral ventricular level. Those of the non-affected side were 48.9, 50.1 ml/100g/min in the basal ganglia level and 47.8, 45.1 ml/100g/min in the lateral ventricular level. This gap between the change of neurological symptom and that of CBF wassignificant.

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We describe a case of small anterior wall aneurysm of the essentially narrow internal carotid artery (ICA) in which during direct operation a large part of the dome tore and its dome wall became valvular. Therefore under temporary trapping the valvular dome wall was put back, and the wrap and clip method with Bemsheet instead of clipping was performed in order to avoid severe stenosis of the ICA. Bleeding from the aneurysm was thereby controlled but an aneurysm recurred from the distal part of the original aneurysmal sac shortly after the operation. The recurrence was attributed to the fact that the range of wrap and clip was the minimum to stop bleeding from the aneurysm. For a small anterior wall aneurysm of the essentially narrow ICA, the wrap and clip method is considered the best choice of treatment to prevent ICA stenosis by clipping. And in these circumstances, this method should be performed as extensively as possible to prevent a potential recurrent aneurysm.

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We report a case of a ruptured aneurysm at the site of the left middle cerebral artery (MCA) fenestration. The patient, 54-year-old female, suffered from subarachnoid hemorrhage on July 19, 1995. She was transfered and admitted to our department on the day of onset. On admission she was neurologically intact except for neck stiffness. Cerebral angiography revealed an aneurysm at the right MCA bifurcation and one at the left M₁ segment. However, the fenestration at the left M₁ segment was not recognized angiographically. The ruptured aneurysm at the proximal end of the fenestration and the right MCA unruptured aneurysm were successfully clipped through the right frontotemporal craniotomy on the day of onset.
Including our case, 29 cases of MCA fenestration with or without cerebral aneurysm had been reported. We discuss the clinical significance of the fenestration of the MCA and the operation through a contralateral approach to the aneurysm at the site of MCA fenestration.

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Titanium alloy currently used in medicine contains 6% of aluminium and 4% of vanadium. It has long been used as titanium plates or pedicle screws. While it is considered to be safe as a material, its durability, especially when used as aneurysm clips, is not clear.
Sugita type titanium aneurysm clips are made in shapes similar to cobalt alloy (Elgiloy) clips except for spring diameter, which was enlarged by 10%. Their neuroradiological and mechanical characteristics are compared with Sugita cobalt clips. CT was taken at 120 KV, 300 mA by hanging a clip on a thread in a plastic bottle filled with saline. Cobalt clips caused strong high density artifacts around the clip with a low density linear shadow along its long axis. The shapes of titanium clips could be seen since they were surrounded by only faint artifacts. T1 weighted (TR: 500ms, TE: 20ms) and T2 weighted (TR: 4100ms, TE: 80ms) MRI images were taken by hanging a clip on a thread in a plastic bottle filled with baby-oil (Johnson & Johnson). The cobalt clip caused on both T1 and T2 weighted images a candle-flame-shaped high-signal-intensity artifact by longitudinal image and triangular high-signal-intensity artifact separated into three blocks on the axial image. Artifacts by titanium clips were about 1/3 that of cobalt clips but the difference was not as big as CT images.
The closing force of titanium clips was measured at 2mm from the tip of the blades, which were opened by 1.5mm. After manually repeating full opening and closing of the clips by clip appliers 500 times, the reduction of closing force remained less than 3%. The closing force of a #2 titanium clip measured at 1mm step from the tip toward the spring base showed an increase in a hyperbolic curve, from 120 to 240g, which was similar to that a #2 cobalt clip. The closing force of a # 2 titanium clip measured at 1.5 mm from the tip when the blades were opened by 0.5mm step from 0.5 to 3.5 mm increased in a straight line from 120 to 160g, which was similar to that of a #2 cobalt clip.
These results show that Sugita titanium clips are durable within tested conditions and they have similar characteristics of closing force to cobalt clips. They seem to be quite useful especially for postoperative radiological follow-up. However, accidental scissoring of titanium clips that are commercially available in Japan has been reported. This may be due to weakness of titanium alloy in both tensile and compression strength, which is only one half that of cobalt alloys. Thus, titanium clips do not seem to be able to totally replace cobalt clips but, with care, they can be used in easily clippable and uncomplicated aneurysms.

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