Surgical treatment for moyamoya disease is basically a combination of direct and indirect revascularization because of the characteristic pathogenesis. Surgical goals are to increase the collateral channels as much as possible and to widely cover the territory of the poor cerebral blood flow. We preoperatively evaluate cerebral perfusion by angiography and single photon emission CT, and plan the direct bypass between STAs and each cortical branch of ACA and MCA. We then add the indirect revascularization over them on the 2 cranial windows. Recently, the middle meningeal artery also has been utilized as a donor of the direct revascularization.
We estimated the postoperative perfusional change of the total revascularizations by SPECT, which showed improved cerebral blood flow and vascular reserve.

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We present anatomical features of the styloid diaphragm, which limits access to the highest portion of the cervical internal carotid artery. Based on the features, we also present a non-invasive technique of approach to the high cervical internal carotid artery lesion. The inferior margin of the styloid diaphragm is a useful preoperative landmark in carotid endarterectomy for determining whether the lesion is surgically accessible.

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While the pterional approach is one of the most used approaches, there are variations. We have practiced the distal sylvian approach by dissection between the superficial sylvian veins. To evaluate the appropriateness and rationale of this approach, we investigated the microsurgical anatomy of the superficial sylvian vein and the frontal and temporal bridging veins.
Of 76 consecutive patients with a cerebral aneurysm clipped by the distal sylvian approach, significantly more had a frontal bridging vein (79%) than a temporal bridging vein (54%; p＜0.01). The superficial sylvian vein tended to influx into the main trunk of the frontal side rather than the temporal side.
These results show that dissection between the superficial sylvian veins preserves the frontal bridging vein, which has a high prevalence, and dissection of the temporal side of the superficial sylvian veins is more effective.

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Indication of early treatment remains controversial for patients with poor-grade (WFNS grade IV and V) subarachnoid hemorrhage (SAH). Since 2006, we have tried endovascular treatment mainly using the Guglielmi detachable coil (GDC) as one treatment option for these patients. In this study, we compared clinical outcome and complications in patients treated in 2004–2005 with those treated in 2006–2007, and evaluated the changes in treatment strategy.
Between 2004 and 2007, we treated 81 patients with poor-grade SAH, and 61 underwent early aggressive treatment in our hospital. For 29 cases (10 males, 19 females, mean age 64.6 years) in 2004–2005 (Group 1), treatment options were early craniotomy (clipping) except for 1 case of intentionally delayed surgery, while for 32 cases (8 males, 24 females, mean age 66.2 years) in 2006–2007 (Group 2), endovascular coil embolization (mainly using GDC) at the acute stage was added to treatment options for cases of high age and/or poor general condition. We compared these 2 groups in terms of percentage of treatment option, clinical course and outcome, assessed with Glasgow Outcome Scale score (GOS) at discharge.
The percentage of patients treated by coil embolization increased from 0% in Group 1 to 20% in Group 2 for Grade IV and 6.7% to 50% for Grade V. The outcomes of patients in Grade IV were better in Group 2 than in Group 1. That is, for Grade IV cases, the percentage of good recovery (GR) significantly increased from 15.4% in Group 1 to 42.9% in Group 2. For Grade V cases, good outcome—GR and moderately disabled (MD)—increased from 13.3% in Group 1 to 26.3% in Group 2, otherwise dead also increased from 13.3% in Group 1 to 31.6% in Group 2 due to uncontrolled general complications. For Grade V cases, more than 50% patients in Group 2 were MD or severely disabled, or in a vegetative state. The incidence of symptomatic vasospasm and hydrocephalus did not differ between Group 1 and Group 2.
The introduction of coil embolization extended the indication of early treatment for poor-grade SAH patients and improved the outcome of those patients. On the contrary, over-indication of coil embolization revealed poor outcome of poor-grade SAH patients.
It is necessary for surgical indication in poor-grade SAH to objectively evaluate grade and familial and social aspects.

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We investigated the current state of and problems in patients with subarachnoid hemorrhage initially diagnosed and treated by general physicians at a local referring hospital and subsequently transferred to our hospital for neurosurgical treatment.
We studied 37 consecutive patients with subarachnoid hemorrhage over a 7-year period from April 2001 to March 2008.
A total of 7 men and 30 women aged 50 to 89 years (average: 71.2±9.5 years) were included in this study. Thirteen patients (35.1%) were referred to our hospital with diagnoses other than subarachnoid hemorrhage. Twenty-three of 27 patients who had CT scans were diagnosed correctly in the referring hospital, while only 1 of 10 patients was correctly diagnosed without CT.
Time from the onset to admission to our hospital ranged from 85 minutes to 144 hours (average: 15.3±29 hours). The reasons of delay in patients who took more than 12 hours to reach us were patients’ delay in visiting the referring hospital in 3 cases and uncertain initial diagnosis in 6. All 6 cases complained of sudden headache, but did not undergo CT. All patients were transferred by an ambulance car, and the duration of transfer ranged from 60 to 120 minutes (average: 85.4±15.7 minutes). None of the patients experienced rebleeding during transfer.
Subarachnoid hemorrhage can be diagnosed correctly at the local primary hospital with CT, allowing appropriate primary treatments. Initial misdiagnosis is the major cause of delay in transferring patients to neurosurgical facilities.

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To clarify the usefulness of intraoperative monitoring of visual evoked potentials (VEPs) in aneurysm surgery, we examined the correlation between the VEP amplitude and postoperative visual function in patients who underwent aneurysmal clipping.
We developed a new light-stimulating device and introduced electroretinogram (ERG) to ascertain retinal light stimulation under total venous anesthesia. The new stimulating device consists of 16 red light-emitting diodes embedded in a soft silicon disk to avoid deviation of the light axis after frontal scalp-flap reflection. Under total venous anesthesia with propofol, ERG and VEP were recorded in 50 patients who were at intraoperative risk for visual impairment. Stable ERG and VEP recordings were obtained in 98 eyes. In one eye, stable ERG was recorded but VEP could not be obtained, because the eye manifested severe preoperative visual dysfunction. In the another eye, the disappearance of ERG and VEP after frontal scalp-flap reflection suggested technical failure attributable to deviation of the light axis. The criterion for amplitude aggravation was defined as a 50% decrease in amplitude compared to the control level. Of 93 eyes without amplitude changes, 2 manifested improved visual function postoperatively and 91 showed no change. Of 3 eyes with intraoperative VEP deterioration and subsequent recovery upon changing the operative maneuver 3 exhibited no change. The VEP amplitude decreased without subsequent recovery to 50% of the control level in both eyes of 1 patient, and she developed homonymous quadrant hemianopsia postoperatively.
With the strategy introduced here it is possible to record stable VEP in almost all cases without severe visual dysfunction. In some patients, postoperative visual deterioration can be avoided by intraoperative VEP monitoring. All patients without an intraoperative decrease in the VEP amplitude were without postoperative deterioration in visual function, suggesting that intraoperative VEP monitoring may help to prevent postoperative visual dysfunction in aneurysmal clipping.

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Aneurysms of the proximal segment of the anterior cerebral artery (A1An) are difficult to treat surgically because of the proximity of perforating arteries frequently adherent to the A1An dome. Among A1Ans, posteriorly projecting A1An represents much more challenge for surgical clipping due to the location behind the parent artery which covers the aneurysm neck and dome. In the last 2 years, 5 patients (8.9% of the treated 56 cerebral aneurysms in our hospital) were identified with a posteriorly projecting A1An. Neck clipping of the A1An was performed in 4 cases via pterional craniotomy, and 3 developed a new cerebral infarction in the territory of the perforators, while in 1 patient we could not evaluate the blood flow of the perforating arteries because of a large intracerebral hematoma. Only 1 patient was treated by selective embolization from the ipsilateral side with no infarction, although catheterization was difficult. Causative factors of postoperative infarction were limited surgical field, direct injury or occlusion of the perforators and compression with either the clip blade or the clip body.
We report a consecutive series of 5 patients with posteriorly projecting A1An focusing on the surgical considerations with a review of the literature.

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We analyzed changes in cerebral hemodynamics due to reconstructive vascular surgery using positron emission tomography (PET) in 4 patients with severe internal carotid artery (ICA) stenosis and contralateral ICA occlusion. Three patients had carotid artery stenting (CAS), while the remaining had superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery. Preoperative cerebral blood flow (CBF) studies of all patients demonstrated various decreases in CBF in a resting state and cerebral vascular reactivity (CVR) to acetazolamide (ACZ) and an increase in the oxygen extraction fraction (OEF) on both sides. These parameters improved on both sides after CAS was performed. Our results indicate that CAS performed on a stenosis contralateral to the site of occlusion will improve cerebral hemodynamics bilaterally and indirectly, patient prognosis. But further clinical trials are required to determine whether CAS significantly reduces in stroke above the occlusion.

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Baclofen, a gamma-aminobutyric acid receptor_B agonist, is used to reduce symptoms of spasticity (hyperreflexia, increases in muscle tone and involuntary muscle activity). In a 25-week observational longitudinal follow-up study we assessed 4 patients who received intrathecal baclofen given by programmable pump. Clinical efficacy was assessed by the Ashworth scale related with the dose of baclofen. Compared with pretreatment values, all patients improved. Although results show the effiicacy of intrathecal baclofen (ITB) therapy for spasticity from stroke, it must be kept in mind that baclofen causes some clinically significant adverse reactions.

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Surgical revascularization through a superficial temporal artery-middle cerebral artery (STA-MCA) bypass is often performed to prevent cerebral ischemic attack. A 74-year-old man who had undergone an STA-MCA bypass presented 10 months after the bypass procedure, with an aneurysm at the anastomosis site reveled by computed tomography (CT) angiography. Follow-up cerebral angiography revealed the aneurysm was gradually growing. We wrapped the aneurysm to prevent rupture, and on the following CT angiography and cerebral angiography, the aneurysm could not be seen. Increasing hemodynamic stress of the anastomosis site may have contributed to the aneurysm’s formation, and the granulation due to the wrapping material or the mechanical spasm of the aneurysm may have contributed its disappearance.

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We report 2 pregnant women with subarachnoid hemorrhage (SAH).
Patient 1 was a 24-year-old woman at 36 weeks of gestation who presented with a disturbance of consciousness and epilepsy. A right internal carotid angiography performed after an emergency Cesarean section showed an aneurysm at the junction of the posterior communicating artery. Although the aneurysm was successfully clipped, the patient died as a result of severe vasospasm.
Patient 2 was a 31-year-old woman at 23 weeks of gestation who presented with headache and nausea. Although computed tomography and magnetic resonance angiography images obtained upon admission suggested SAH resulting from a right internal carotid aneurysm, the patient refused subsequent radiological examinations because of her concern regarding the adverse effect of the radiation and contrast medium on the fetus. An angiography performed after a Cesarean section revealed an aneurysm at the junction of the right internal carotid artery and the posterior communicating artery, which was successfully clipped.
We concluded that the optimal treatment strategy for SAH during pregnancy should be established based on the gestational stage and the patient’s condition.

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