Masaaki Fukuoka

Intraventricular Hemorrhage after Carotid Stenting

Purpose: To report an important complication related to carotid stenting. Methods and Results: A 71-year-old man with symptomatic subtotal occlusion of the left internal carotid artery had a 30-mm lesion treated percutaneously with implantation of 2 stents. Although the procedure was completed satisfactorily, left intraventricular hemorrhage occurred 4 hours later, possibly related to hyperperfusion injury. The patient expired 30 days after the stent procedure. Preoperative single-photon emission computed tomography revealed severely reduced vasoreactivity in the affected territory after acetazolamide challenge. Conclusions: The risk of hyperperfusion injury must be considered and minimized in patients with significant restriction of regional vasoreactivity. We recommend that cerebral hemodynamic status be determined prior to carotid stenting.

Intracranial lipomas: Current perspectives in their diagnosis and treatment

Intracranial lipomas are very rare lesions, which are probably congenital. Though they can occur anywhere in the intracranial space, a high proportion of cases tend to be ++located around the midline. They are usually asymptomatic. When symptoms do occur, they are frequently the result of co-existing general clinical conditions. Lipomas used to be reported mainly as incidental findings at autopsy, but advances in neuroimaging techniques have greatly improved the likelihood of their being discovered during life. Surgical extirpation is not necessary in the majority of patients, many of whom show remarkable clinical improvement following shunt procedures for obstructive hydrocephalus (when present) as well as vigorous treatment of co-existing conditions.

Cerebellopontine angle lymphoma: a case report and review of the literature

BACKGROUND Although malignant lymphomas of the central nervous system have been reported to be increasing in frequency, cerebellopontine (CP) angle lymphoma is rare and only 13 cases have been reported previously in the literature. CASE PRESENTATION A 63-year-old woman had progressive dizziness and nausea for 2 months. Computed tomography scanning and magnetic resonance imaging (MRI) revealed a mass lesion in the left CP angle, that was compressing the lateral-dorsal aspect of the pons and the fourth ventricle. This tumor was avascular on angiography. The tumor was surgically removed through a left lateral suboccipital approach. It was considered to arise from the subarachnoid space of the CP angle cistern. For some reason, the histologic diagnosis was not definitively made, and therefore radiation therapy was not planned. The tumor recurred within 50 days after the tumor excision. Surgical excision of the recurrent tumor was performed again. The histologic diagnosis was B-cell type malignant lymphoma. Radiation therapy was performed. In the 27 months since irradiation, a recurrent tumor has not been detected on MRI. CONCLUSIONS Although erosion and expansion of the internal auditory canal suggest an acoustic neurinoma, CP angle lymphoma can, in rare circumstances, erode the internal auditory canal. There are three distinct patterns in which malignant lymphomas occupy the CP angle: (1) an extra-axial CP angle lymphoma, (2) an intra-axial lymphoma extending to the CP angle, and (3) a leptomeningeal lymphoma presenting as a CP angle lesion. Although malignant lymphomas rarely occupy the CP angle, it should be considered in the differential diagnosis of CP angle tumors. It is desirable to obtain a frozen section in all CP angle tumors during surgery to identify the tumor, because aggressive removal is not necessary, but radiation therapy should additionally be performed for malignant lymphomas.

Follow-up Study after Intracranial Percutaneous Transluminal Cerebral Balloon Angioplasty

Purpose of this research was to find specific characteristics angiographic lesions appropriate for intracranial percutaneous transluminal cerebral angioplasty (PTCBA). Forty-two clinically symptomatic patients with 42 haemodynamically significant intracranial lesions were treated by PTCBA between January 1992 and May 1996. Before the angioplasty treatment, the patients were classified into three groups according to angiographic lesion characteristics. They were followed after PTCBA from one month to six years to compare the three groups. Primary end points were death, stroke, or bypass surgery. The clinical success rates in type A, B and C groups were 92%, 86% and 33% (p=0.0032), respectively. Cumulative risks of fatal or nonfatal ischaemic stroke in type A, B and C groups were 8%, 12% and 56%, respectively. PTCBA for intracranial simple (type A) lesions produces a favourable clinical outcome for symptomatic patients.

Preconditioning by 5-min forebrain ischemia reduced brain edema and cell damage following 15-min forebrain ischemia in gerbils.

遅発性神経細胞死にアポトーシス(programmed cell death)が関与しているという最近の報告は,「海馬CA1の神経細胞が短時間の前脳虚血に脆弱で選択的な細胞死を引き起こすことは,将来の長時間の虚血侵襲の際に脳全体と生命を守っていることに役立っている」という仮説が成り立つ可能性を示唆する.我々は,この仮説を検証する一つの実験方法として,砂ネズミを用い,予め5分間の前脳虚血を負荷せずに15分間前脳虚血を加えた群(A群)と,予め5分間の前脳虚血を負荷し海馬CA1の選択的な細胞死を生じさせておき,10日後に15分間前脳虚血を負荷した群(B群)において,2週間の観察で,B群では有意に生存率が高く,体重減少も軽減していることを前回報告した(脳卒中19: 145-152, 1997).しかし,2週間生き残った砂ネズミの組織学的検討では両群の違いはほとんどなかったため,今回は死亡する前の時点での脳浮腫測定および組織学的解析を新たに行った.大脳の水分含有量を15分間前脳虚血の2時間後,2日後,7日後について調べたところ,B群はA群より脳浮腫の増加が有意に抑制されていた(p<0.01).また,15分間前脳虚血の2日後の大脳皮質および視床下部の組織学的検討において,B群では細胞障害が少ない傾向が認められた.予め負荷しておいた5分間前脳虚血は,生体にとって好ましい効果をもたらしたが,その効果には脳浮腫抑制および細胞障害の軽減が関与していることが示された.