We investigated the usefulness of the posterior tibial nerve somatosensory evoked potentials (PTN-SEP) for detecting the cerebral blood flow insufficiency of the anterior cerebral artery (ACA) during anterior communicating (Acom) or distal ACA aneurysm surgery. PTN-SEP monitoring was employed in 112 patients of Acom and 23 patients of distal ACA aneurysm. After dural incision, control data were recorded, and a decrease of more than 50% in the amplitude of P37-N45 was defined as significant. We evaluated the intraoperative PTN-SEP findings, causes of PTN-SEP change, and motor outcomes in the lower extremities. PTN-SEP changes were observed in 21 patients.
The causes of SEP change were thought to be attributable to blood flow insufficiency with aneurysmal bleeding, with or without temporary occlusion on the ACA in 10 patients. In the other 10 patients, the cause was intensive temporary occlusion. In the last patient, inappropriate clipping on the parent artery was the cause of SEP change. No obvious difference was observed between bilateral and unilateral ACA occlusion. Following the release of the occlusion and repositioning of the clip, PTN-SEP was recovered to the control value in all but 1 patient. Of these 21 patients, 11 did not show any postoperative motor paresis of the lower extremity; transient motor paresis was recognized in 10 patients.
Despite the large variability of territories of the ACA and collateral circulation via the leptomeninges, intraoperative PTN-SEP monitoring was helpful in the operative maneuver, such as ACA occlusion.

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頭痛を初発症状として急速進行性に発症し, Foville症候群に第IX～XH脳神経の障害を合併した橋出血の6歳男児例を報告した.発症当初のCTでは橋腹側に高吸収の腫瘤陰影を認め, 脳幹部腫瘍が疑われたが, MRIにより血腫と診断された.経時的にMRIを撮像したところ, 出血後の変化に特徴的な画像が得られた.脳血管造影では異常所見を認めなかったが, 発症4カ月以降の造影MRI所見から出血の原因として血管腫の存在が疑われている.保存的治療により軽快し, 発症後3年間神経学的にほぼ無症状で経過中である.脳幹部出血の診断および治療方針の決定におけるMRIの有用性を報告するとともに, 若年性非高血圧性橋出血症例に関する文献的考察を行った.

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We present a case of cavernous angioma in the medulla oblongata that was successfully excised. A 29-year-old man complained of gait disturbance, dysphagia, vertigo, diplopia and numbness of his left hand. Neurological examination revealed left VI, VII, IX, and X cranial nerve palsy. He also had left hemiparesis and right hemihypesthesia. MRI scan demonstrated a ring-like high intensity area in the dorsal portion of the medulla oblongata in T₁-weighted images. Three weeks after the onset, the patient underwent an operation in which a suboccipital approach was used. The lesion was mostly hematoma, and a small vascular mass was resected. Histological examination disclosed a cavernous angioma. After surgery, the patient's neurological deficits improved. Surgical resection of cavernous angioma in the medulla oblongata is a reasonable choice of treatment, in accordance with previous reports.

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57歳という比較的高齢である男性における, 動静脈奇形 (AVM) による原発性橋出血の1例を報告した.原発性橋出血の多くは, 成人にみられ, その原因はほとんど高血圧症であるといわれている.しかし, 小児に見られる橋出血においては, その原因は血管奇形によるものが多いといわれている.本例は, 既往に高血圧等の脳血管障害をきたす危険因子がなく, 発症直後のCTscanにて橋上部右外側被蓋に血腫を認め, 脳室穿破を合併していた.発症3ヵ月後のenhanced CTでは, 橋上部被蓋に低吸収域及び, その中に小さなenhanced spotを認めた.左椎骨動脈写により, 同部位に上小脳動脈をfeederとするAVMが確認され, このAVMが出血の原因と考えられた.本例のごとく50歳以上の原発性橋出血において, CT, 脳血管写上AVMが確認された例は, 極めて稀であると思われる.

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The mechanism through which ischemic manifestations develop in patients with middle cerebral artery (MCA) stenosis is still uncertain. It may cause ischemic symptoms through both embolic and hemodynamic mechanisms. In this study, we compared the findings from cerebral angiograms with single photon emission computed tomography (SPECT) in patients with M1 stenosis to determine the pathogenesis of ischemia.
At our hospital from 1994 to 2000, 14 patients (12 males and 2 females; mean age, 60.9; range, 31 to 85 years) with angiographically demonstrated symptomatic M1 stenosis were enrolled in this study. In 10, their stenotic lesion was located at the proximal site of the perforating arteries and for the other 4, stenosis was found at the distal site. Nine presented with transient ischemic attack (TIA) and 5 with completed stroke for an initial episode. The discrepancy in regional cerebral blood flow (rCBF) was evaluated in relation to the site and degree of stenosis, type of ischemic presentation, and frequency of ischemic events.
There was no significant difference in CBF between the patients with stenosis involving the proximal site and those with distal stenosis; but the cortical CBF decreased significantly in those with severe stenosis compared with moderate stenosis.
The cortical CBF of those who had a complete stroke is similar to that of the patients with TIA; but CBF of BGA decreased significantly in those with a complete stroke. The single ischemic event group showed a significant decrease in cortical CBF. On the other hand, the group with multiple ischemic events exhibited normal hemodynamics.
We concluded that multiple ischemic events that occurred in M1 stenosis are caused by an embolic mechanism.

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【目的】当院における過去10年間の脳卒中診療の，内容とその変化について総括した．【方法】1997∼2001年までを前期，2002∼2006年までを後期とし，疾患分布や診療内容について検討した．【結果】総患者数は2,699人（前期1,238・後期1,461），疾患の内訳は虚血性（CI）/脳出血（ICH）/クモ膜下出血（SAH）が前期・後期でそれぞれ59.2%/26.5%/14.3%・62%/24.2%/12.9%であった．治療内容での変化は動脈瘤治療における血管内手術の増加（10%→25%）と，超急性期脳梗塞に対するtPA療法の導入（H16.12∼）であった．予後良好例はCIが，死亡率はSAHが最も多い傾向があった．またICHは機能予後不良例が最も多かった．【結論】当院における脳卒中の治療成績は前後期で大きな改善はなかったが，患者の平均年齢は前後期を比較すると2.4歳高齢化し，平均在院日数は27.2日から23.5日と3.7日短縮した．また，全脳卒中急性期患者の19.6%に外科的治療を要した．

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In cases of intracranial arteriovenous malformation (AVM) associated with aneurysms, one-stage surgery may be preferable. However, in some cases, it is not easy to determine whether to treat the aneurysms or the AVM first. We present a case of upper vermian hematoma due to a ruptured large AVM of this site associated with two unruptured basilar top aneurysms. These two lesions were successfully treated in 2 separate operations. A 40-year-old female was transferred to our hospital on the 5th day after the onset. On arrival, she was alert, and cerebellar symptoms were minimal. The AVM was fed mainly by the bilateral superior cerebellar arteries (SCA) and drained into the vein of Galen and straight sinus. Two unruptured aneurysms were located at the basilar top and at the origin of the right SCA, respectively. First, the aneurysms were successfully clipped via the right zygomatic approach on the 15th day after the ictus. The postoperative course was uneventful, but right ophthalmoplegia developed. This showed improvement approximately 2 months postoperatively. On the 36th day, a second operation was performed for the AVM via the right occipital transtentorial approach. This approach was suitable for removal of the nidus at this region, but meticulous procedure was needed to preserve perforating arteries feeding the thalamic region, because the patient showed mild hemiparesis and CT and MRI revealed a small infarcted area at the right thalamus.

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A 76-year-old man who had suffered subarachnoid hemorrhage about 10 years ago did not undergo surgery but other details were not clear. When admitted to our hospital, his consciousness level was 3-1-5 (Glasgow coma scale) and right hemiparesis was apparent. In the computed tomography (CT) scan, a cerebral hematoma (64×43×60mm) and subarachnoid hemorrhage appeared in the left frontotemporal area and a circular low-density area was observed in the cerebral hematoma. Enhanced CT enhanced the low-density area. In magnetic resonance (MR) and cerebral angiography, a cerebral aneurysm (8×7×7mm) was observed at the bifurcation of the M1-M2 and cystic expansion (17×13×15mm) adjoined the aneurysm. We considered pseudoaneurysm or thrombosed giant aneurysm. We conducted coil embolization of the aneurysm using Guglielmi electrolytically detachable coils, then evacuated cerebral hematoma by stereotactic aspiration surgery. V-P shunt was conducted for normal pressure hydrocephalus after 23 days. Follow-up MRI and cerebral angiography showed thrombosis of aneurysm and disappearance of the cerebral hematoma. We discuss neuroimaging features of the giant aneurysm and pseudoaneurysm.

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近赤外線を用いた局所脳酸素飽和度(rSO_2)測定が,術後合併症の早期検出に有用であるかどうかを検討した.対象は脳動脈瘤クリッピング患者20例とし,関頭と反対側の前頭部でrSO_2を測定した.術後経過良好群は16例で,術後の合併症群は4例(脳浮腫2例,脳内出血2例)であった.われわれの施設で測定した健常者のrSO_2は68.5±5.3%(n=131)で,これを正常値とした.術後経過良好群では,rSO_2は正常値にこ近い値で推移した.一方合併症群では,いずれも術後徐々に昇する傾向を示し,最終的には90%以上の高値に達していた.rSO_2の測定値は,頭蓋内圧亢進に伴って上昇する傾向にあり,開頭と反対側での測定は頭蓋内合併症の早期検出に有用であると考えられた.

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In most patients with cerebral aneurysms of the peripheral portion of the anterior inferior cerebellar artery or posterior inferior cerebellar artery, selective endovascular aneurysmal obliteration is very difficult. Endovascular occlusion of the parent artery may be an easier approach, but this can have potentially unfavorable clinical consequences due to ischemic complications. Here we propose aneurysmal neck clipping with preservation of blood flow in the parent artery as an ideal firstline treatment for such lesions, although expertise in microsurgical techniques and anatomical knowledge are required.

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An unusually prolonged course of traumatic encapsulated epidural hematoma was reported.

A 44-year-old man had visited the local hospital with lt. frontal skull fracture on the acute epidural hematoma caused by falling down due to excessive alcohol intake. The conservative observation had been taken because of neither enough volume of the hematoma to do the surgical intervention nor neurological deficit. He was admitted to our hospital on 40th day after the injury with deteriorating headache and dizziness. The CT scan showed slowly developed lt. frontal epidural hematoma. Total extirpation of the epidural hematoma enveloped by thick capsule was performed on post-injury day 47. After surgery, his condition was fully recovered.

Histologically, the hematoma capsule was consisted of fibrous and inflammatory tissues with hemosiderin deposit and partial ossification, which findings might be similar to traumatic chronic subdural hematoma.

The slowly progressed chromic epidural hematoma should be kept in mind during conservative observation for a thin epidural hematoma.

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要旨：小脳出血では悪心や嘔吐を高頻度に伴い，機能回復の阻害要因になるので対症療法が重要である．ペルフェナジン（PPZ）内服で難治性嘔吐は消失したが，副作用の錐体外路症状に対処する必要があった2 症例を報告した．症例1 では片葉小節葉と傍索状体を巻き込むと推定される小さな血腫があり，頭位変換時などに嘔吐を繰り返したが，PPZ 12 mg/日の内服で嘔吐は消失した．内服開始6 週間後に減量し，その数日後からアカシジアが出現したが内服中止後に消失した．症例2 は小脳後葉に大きな血腫があり，小脳性認知情動症候群と反復する嘔吐が遷延してほぼ寝たきりであった．PPZ 24 mg/日で嘔吐が止まり機能回復訓練を実施できたが，パーキンソン症候群が目立ってきた．手関節の歯車様筋固縮に明らかな左右差があったので，もともと軽度のパーキンソン病がありPPZ により無動が悪化した可能性がある．PPZ 中止とレボドパ配合剤の内服で改善した．

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infraoptic course of ACAを合併した56歳女性の破裂前父通動脈瘤の1例を報告した.infra00ticcourseofACAは比較的稀でR.RobinSon(1959年)が剖検例を報告して以来,39例の報告をみるのみである.その名称についてもinteroptic course of ACA, carotid anterior cerebral artery anaStomosisなどさまざまなよばれ方をしている.本論文では本血管奇形に合併するanomalyである眼動脈が,外頸動脈から分岐することによる関頭に伴う視力障害の問題,および本異常血管の発生起源について考察した.

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【目的】内耳道内の前下小脳動脈meatal loopに生じた破裂脳動脈瘤に対してcoilによるinternal trappingを施行した1例を経験したので，文献的考察を含めて報告する．【症例】92歳女性，突然の頭痛，めまい，嘔吐を発症し，頭部CTでくも膜下出血，脳血管造影と頭部3D-CTAで左内耳道内に3.6 mm大の紡錘状左前下小脳動脈瘤を認めた．動脈瘤の位置・年齢・全身状態などを考慮してコイルによるinternal trappingを施行した．【結論】内耳道内前下小脳動脈瘤は瘤頚部クリップや瘤内塞栓が困難な場合があり，時にtrappingが選択される．Coilによるinternal trappingは遂行可能な治療選択肢だが，前下小脳動脈灌流域の梗塞に注意する必要がある．

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It is important to prevent intraoperative aneurysm rupture in patients with ruptured cerebral aneurysms, because intraoperative bleeding can have catastrophic consequences. It is very useful for aneurysm surgeons trying to prevent this complication to know the incidence of intraoperative ruptures, the clinical grades and the location of aneurysms in which they occur and, when during operations intraoperative ruptures occur most frequently. We evaluated 905 of our patients with ruptured cerebral aneurysms and discussed the prevention of intraoperative rupture.
Intraoperative aneurysm rupture was noted in 117 cases (13%). That rate was significantly higher in cases with middel cerebral artery aneurysms, anterior communicating artery aneurysms and anterior cerebral artery aneurysms than in those with internal cerebral artery aneurysms and vertebrobasilar artery aneurysms. The incidence was significantly higher in cases undergoing surgery on Day 0 to 3 and 8 to 14 than on Day 4 to 7 and after Day 15. The intraoperative bleeding rate was also significantly higher in cases with Hunt and Kosnik Grade III to V than in those with I to II. The rate of intraoperative hemorrhage was significantly lower in cases enduring temporary occlusion to prevent intraoperative bleeding than in those without temporary clipping. Over 90%of the intraoperative rupture occurred at the timing of aneurysm dissection and application of clips.
Temporary clipping effectively prevents intraoperative bleeding. That should be followed by aneurysmal dissection with sharp microsurgical technique, when the intraoperative rupture may most likely occur due to the aneurysm tightly adhering to the surrounding tissues and its thinned and reddened wall. Especially, temporary clips should be used in clinical grade III to V patients with aneurysms in the anterior communicating artery, the distal anterior cerebral artery or the middle cerebral artery, who undergo surgery on Day 0 to 3 or Day 8 to 14.
To avoid aneurysm rupture when retracting the frontal lobe, methods to decrease the retractor pressure should be devised. And the brain spatula should be pulled in the proper direction according to the position of aneurysms, involving the direction of aneurysmal domes, the location of blebs, and these possible adherence to the surrounding tissue. As insufficient dissection of the neck causes bleeding in clip application, it should be remembered that the aneurysmal neck must be sufficiently dissected from the surrounding tissue with temporary clipping. A wrapping aneurysm clip should be applied for a blister-like aneurysm in the anterior wall of the internal cerebral artery.

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