Tomosato Yamazaki

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.

ANCA-associated vasculitis (AAV) causing bilateral cerebral infarction and subsequent intracerebral hemorrhage without renal and respiratory dysfunction

A 56-year-old man complained of headache and the analgesia of the four extremities. Laboratory data presented signs of inflammation, but no other abnormality such as renal or respiratory dysfunction. Two months after the appearance of the primary symptoms, he developed cerebral infarction of the bilateral corona radiata. The patient did not have any of the risk factors for cerebrovascular disease. He was diagnosed with anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) because the systemic examinations revealed only that he tested positive for anti-neutrophil cytoplasmic autoantibody (ANCA). Moreover, the biopsy of the sural nerve displayed microscopic polyangitis (MPA). Despite undergoing steroid pulse therapy, the patient died from the fatal cerebral hemorrhage. The clinical course of AAV is rapid progressive. In cases of atypical cerebrovascular disease, the possibility of ANCA should be investigated.

Atretic cephalocele – report of two cases with special reference to embryology

Abstract.We report two cases of atretic cephalocele, a diverse form of cranium bifidum. The patients were 15-year-old and 3-month-old girls, who each had a hard, nonpulsatile, nonreducible lump covered by alopecic scalp in the parieto-occipital area. They were surgically treated. In case 2, microscopical examination of the operative specimen revealed a meninges under the mass, which was devoid of nervous tissue. Such lesions have rarely been reported, and their essential nature is still the subject of controversy. Pathological and embryological aspects of atretic cephalocele are discussed on the basis of the findings; the neural crest remnant was assumed to be the developmental origin of the lesion in each of these cases.

Carotid artery stenting without post-stenting balloon dilatation

Purpose To evaluate the clinical outcome and MRI findings after carotid artery stenting (CAS) without post-dilatation. Methods Between May 2005 and April 2012, a total of 169 consecutive patients (61.4% symptomatic) underwent 176 CAS procedures performed with an embolic protection device (GuardWire, n=116; FilterWire EZ, n=60). All stents were deployed without post-dilatation. Periprocedural complications and mid-term outcomes were analyzed. Results The stroke rate was 2.3% within 30 days post-CAS (asymptomatic patients 1.5%; symptomatic patients 2.8%). Cerebral infarction occurred in one asymptomatic patient (1.5%) and one symptomatic patient (0.9%). Intracranial hemorrhage occurred in two symptomatic patients (1.9%). Post-CAS diffusion-weighted imaging (DWI) revealed a high-intensity area in 26 of 176 procedures (14.8%). Ipsilateral stroke after 31 days occurred in two patients (1.1%) and restenosis occurred in six (3.4%). A post-CAS comparison of the embolic protection devices revealed no difference in stroke incidence within 30 days and in DWI high-intensity area. Conclusions Our CAS procedure without post-dilatation is feasible, safe and associated with a low incidence of stroke and restenosis.

Cerebral Embolism as a Complication of Paroxysmal Nocturnal Hemoglobinuria

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Endovascular treatments for posterior cerebral artery aneurysms and vascular insufficiency of fetal-type circulation after parent artery occlusion

We present a retrospective analysis of endovascular treatments for posterior cerebral artery (PCA) aneurysms and discuss the susceptibility of a fetal-type PCA to vascular insufficiency after parent artery occlusion. Among 1207 aneurysms treated with endovascular therapy between March 1997 and March 2013 in our institution, 10 patients (0.8%) presented PCA aneurysms. The principal strategy was to employ selective coil embolization for the aneurysm. However, in certain cases of fusiform or dissecting aneurysms, we performed parent artery occlusion with coils. Clinical and radiological data were collected from hospital charts and evaluated retrospectively. The mean age was 52.7±15.6years (range, 12-65years). Five patients (50%) were admitted with a subarachnoid hemorrhage, and one patient presented with slowly developing paralysis. The remaining four patients were diagnosed incidentally. Five patients underwent selective coil embolization, and five patients underwent parent artery occlusion. All endovascular therapies were successfully performed. However, two patients in the parent artery occlusion group suffered cerebral infarction, and both patients exhibited a fetal-type PCA. The remaining three patients in the parent artery occlusion group exhibited an adult-type PCA and did not suffer a cerebral infarction. Endovascular treatment with either selective coil embolization or parent artery occlusion is safe and effective as the long as the anatomical type of the PCA is considered. Patients with a fetal-type PCA may develop vascular insufficiency upon parent artery occlusion. Neurosurgeons should attempt to preserve the parent artery using a flow-diverting stent or stent-assisted technique for a fetal-type PCA aneurysm.

Endovascular Embolization of Brain Arteriovenous Malformations with Eudragit-E

Eudragit-E was originally developed as a non-adhesive liquid embolic material in the late 1990s and is a copolymer of methyl and butyl methacrylate and dimethylaminoethyl methacrylate that is dissolved in ethanol and iopamidol. This material has been used for endovascular embolization of brain arteriovenous malformations (AVMs) for some time but is currently not widely used. Because safety and feasibility of Eudragit-E has not been well documented, we here report our experience using this material for treating 22 human brain AVMs. From June 1998 to February 2014, 30 endovascular procedures using Eudragit-E were performed to treat 22 patients, including 14 men and 8 women with a mean age of 41.1 years (15–70 years). The mean follow-up period was 56 months (12–129 months), and the Spetzler-Martin grades were I (4 patients), II (9 patients), III (5 patients), and IV (4 patients). Residual AVMs were treated with stereotactic radiosurgery or surgery. The rate of complete obliteration with embolization alone was 27.3%. The overall obliteration rate after endovascular embolization with/without subsequent stereotactic radiosurgery or surgery was 72.7%. Eudragit-E caused two cases of cerebral infarction. One case of intracerebral hemorrhage due to postoperative hemodynamic changes also occurred. The rate of complications directly related to embolization was 10.0%. The safety and effectiveness of Eudragit-E embolization were satisfactory.

Carotid Artery Stenting in Right-sided Aortic Arch: A Case Report

The present report describes a patient with pseudo-occlusion of the left internal carotid artery accompanied by aortic anomalies consisting of right-sided aortic arch with aberrant left subclavian artery arising from Kommerell’s diverticulum. Initial attempt of carotid artery stenting via the trans-femoral approach was unsuccessful because of low origin of the left common carotid artery. Therefore, carotid artery stenting (CAS) via the trans-brachial approach was successfully performed with distal balloon protection. Eight months later, the patient presented with restenosis of the left internal carotid artery, and CAS via the trans-brachial approach was performed again. CAS via the trans-brachial approach should be considered when standard femoral access is relatively contraindicated due to aortic anomalies consisting of a right-sided aortic arch.

Ventriculoperitoneal shunt malfunction secondary to distal catheter entrapment at the right paracolic gutter.

Dear Editor, Ventriculoperitoneal (VP) shunt placements are commonly used in management of hydrocephalus [1]. Various complications, such as infection, proximal or distal catheter occlusion, and valve malfunction, have been reported [5]. Other unusual complications such as distal catheter migration and knotting have also been described [3, 5]. However, distal catheter entrapment at the right paracolic gutter has not been reported. The paracolic gutter is an area between the wall of the abdomen and colon. We report a case of VP shunt malfunction secondary to distal catheter entrapment at the right paracolic gutter. The patient was treated to stimulate bowel motility, and unnecessary shunt revision was avoided. Abdominal computed tomography (CT) with multiplanar reconstruction (MPR) was useful in diagnosing this rare condition. The Japanese female had a medical history of left thalamic and intraventricular hemorrhage with acute hydrocephalus that was associated with Moyamoya disease at the age of 46 years. She had undergone emergent bilateral external ventricular drainage and then scheduled VP shunt surgery. Her Glasgow Coma Scale (GCS) score was 14 (E4 V4 M6), and she was discharged to a rehabilitation hospital. Almost 1 year later, she was referred to our hospital with impaired consciousness. Earlier in the morning, she had been normal, but her consciousness gradually decreased, and she could not open her eyes by noon. Initially, her GCS score was 5 (E1 V1M3). She had no fever and no significantly abnormal general blood examination findings. Brain CT revealed ventriculomegaly (Fig. 1a and b). We diagnosed her condition as exacerbation of hydrocephalus. The shunt systems’ subcutaneous tract was normal, and a shunt reservoir was easy to push and refilled well. A shunt tap demonstrated good proximal flow of clear cerebrospinal fluid (CSF) and normal transit of the contrast medium into the ventricle. However, the contrast medium did not spread smoothly into the peritoneal cavity (Fig. 1d). Abdominal MPR-CT after the shunt tap showed that the distal catheter was trapped at the right paracolic gutter, resulting in functional dysfunction (Fig. 1e). The patient was digitally disimpacted and then given a suppository laxative to stimulate bowel motility under close neurological monitoring. She subsequently passed gas and had a bowel movement. Consciousness rapidly improved. The next day, her GCS was normal at 14 (E4 V4 M6). Hydrocephalus and the distal catheter entrapment were resolved (Fig. 1c and f). She was discharged with appropriate bowel regimen instructions. This was a rare case in which the distal catheter was occasionally trapped at the right paracolic gutter, and correct CSF drainage was disturbed. This functional disturbance was diagnosed by shunt tap and CT. Because the patient was shunt dependent, rapid deterioration of consciousness occurred by acute distal catheter entrapment. The consciousness was not changed soon after the shunt tap, but rapidly changed after a few hours according to the improvement of bowel movements. We found one other similar previous report describing a kink in the distal catheter by dilated colonic bowel loops filled with fecal contents [2]. The kink was suspected after plain X-ray abdominal imaging. The patient was treated with an enema, and the clinical symptoms were dramatically relieved. Shunt revisions were avoided in both cases because the malfunctions were caused by functional, not organic, obstruction. Avoiding * Tetsuya Yamamoto tetsu_tsukuba@yahoo.co.jp

Abducent nerve palsy treated by microvascular decompression: a case report and review of the literature

Too few cases of isolated abducent nerve palsy caused by neurovascular compression syndrome have been reported. We here report on a case of abducent nerve palsy caused by neurovascular compression syndrome that was successfully treated by microvascular decompression (MVD). A 46-year-old male presented with a 6-month history of right-sided persistent abducent nerve palsy. High-resolution magnetic resonance imaging revealed a neurovascular contact of the vertebral artery with the right abducent nerve. MVD was performed via a retrosigmoid craniotomy, with remarkable improvement of the palsy. Our report suggests that MVD might be considered as an optional treatment if the symptoms progress or persist.