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Takeshi Satow, Shigeki Yamada, Miyuki Yagi and Masaaki Saiki

The authors report a case of superficial siderosis of the CNS that developed after ventriculoperitoneal (VP) shunt placement for normal-pressure hydrocephalus.

A 65-year-old woman had undergone VP shunt insertion for normal-pressure hydrocephalus. Her gait disturbance, memory disturbance, and urinary incontinence all improved after the procedure. Two years later, however, her gait became ataxic and her appetite became poor. Brain MR imaging revealed a rim of hypointensity on T2-weighted sequences, enveloping the surface of the cortical fissure, cerebellum, and brainstem. Superficial siderosis of the CNS was diagnosed. Steroid administration improved her symptoms.

The authors know of only one case of superficial siderosis developing after VP shunt surgery in the English-language literature. Superficial siderosis should be acknowledged as a possible complication of VP shunt.

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Shigeki Yamada, Masatsune Ishikawa, Kazuo Yamamoto, Tadashi Ino, Toru Kimura, Shotai Kobayashi and Japan Standard Stroke Registry Study Group


The present study aimed to investigate aneurysm locations and treatments for ruptured cerebral aneurysms associated with secondary normal-pressure hydrocephalus (sNPH) after subarachnoid hemorrhage (SAH) by using comprehensive data from the Japanese Stroke DataBank.


Among 101,165 patients with acute stroke registered between 2000 and 2013, 4693 patients (1482 men, 3211 women) were registered as having had an SAH caused by a ruptured saccular aneurysm. Of them, 1448 patients (438 men and 1010 women; mean age 61.9 ± 13.4 years) who were confirmed to have or not have coexisting acute hydrocephalus and sNPH were included for statistical analyses. Locations of the ruptured aneurysms were subcategorized into 1 of the following 4 groups: middle cerebral artery (MCA; n = 354), anterior communicating artery and anterior cerebral artery (ACA; n = 496), internal carotid artery (ICA; n = 402), and posterior circulation (n = 130). Locations of 66 of the ruptured aneurysms were unknown/unrecorded. Treatments included craniotomy and clipping alone in 1073 patients, endovascular coil embolization alone in 285 patients, and a combination of coiling and clipping in 17 patients. The age-adjusted and multivariate odds ratios from logistic regression analyses were calculated after stratification using the Fisher CT scale to investigate the effects of the hematoma volume of SAH.


Acute hydrocephalus was confirmed in 593 patients, and 521 patients developed sNPH. Patients with a ruptured ACA aneurysm had twice the risk for sNPH over those with a ruptured MCA aneurysm. Those with an ACA aneurysm with Fisher Grade 3 SAH had a 9-fold-higher risk for sNPH than those with an MCA aneurysm with Fisher Grade 1 or 2 SAH. Patients with a ruptured posterior circulation aneurysm did not have any significant risk for sNPH. Clipping of the ruptured aneurysm resulted in twice the risk for sNPH over coil embolization alone.


Patients with low-grade SAH caused by a ruptured MCA aneurysm had a low risk for the development of sNPH. In contrast, patients with high-grade SAH caused by a ruptured ACA aneurysm had a higher risk for sNPH. Endovascular coiling might confer a lower risk of developing sNPH than microsurgical clipping.

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Shigeki Yamada, Yasushi Takagi, Kazuhiko Nozaki, Ken-ichiro Kikuta and Nobuo Hashimoto


The aim of this study was to identify the natural history of untreated cerebral arteriovenous malformations (AVMs) and the risk factors for subsequent hemorrhage after an initial AVM diagnosis.


The authors studied 305 consecutive patients with AVMs at the Kyoto University Hospital between 1983 and 2005. These patients were followed up until the first subsequent hemorrhage, the start of any treatment, or the end of 2005. Possible risk factors that were investigated included age at initial diagnosis, sex, type of initial presentation, size and location of the AVM nidus, and the venous drainage pattern. Subsequent hemorrhage occurred in 26 patients from the hemorrhagic group during 380 patient–years, and in 16 patients from the nonhemorrhagic group during 512 patient–years.


The annual bleeding rate in the hemorrhagic group was 6.84% after the initial hemorrhage; however, that rate decreased in the first 5 years (15.42% in the first year, 5.32% in the subsequent 4 years, and 1.72% in more than 5 years). In the nonhemorrhagic group (annual bleeding rate of 3.12%), the patients initially presenting with headaches (annual bleeding rate of 6.48%) or asymptomatic presentations (annual bleeding rate of 6.44%) had a higher risk for subsequent hemorrhage. Conversely, those patients presenting with seizures (annual bleeding rate of 2.20%) or neurological deficits (annual bleeding rate of 1.73%) had a lower risk. A significantly increased risk (p < 0.05) of rebleeding was found among children (hazard ratio [HR] = 2.69), females (HR = 2.93), or patients with deep-seated AVMs (HR = 3.07).


Children, females, and patients with deep-seated AVMs had a threefold increased risk of rebleeding after an initial cerebral AVM. This increased risk was highest in the first year after the initial hemorrhage, and thereafter gradually decreased.

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Shigeki Yamada, Teruo Kimura, Naoto Jingami, Masamichi Atsuchi, Osamu Hirai, Takahiko Tokuda, Masakazu Miyajima, Hiroaki Kazui, Etsuro Mori, Masatsune Ishikawa and the SINPHONI-2 Investigators


The study aim was to assess the influence of presurgical clinical symptom severity and disease duration on outcomes of shunt surgery in patients with idiopathic normal-pressure hydrocephalus (iNPH). The authors also evaluated the cerebrospinal fluid tap test as a predictor of improvements following shunt surgery.


Eighty-three patients (45 men and 38 women, mean age 76.4 years) underwent lumboperitoneal shunt surgery, and outcomes were evaluated until 12 months following surgery. Risks for poor quality of life (Score 3 or 4 on the modified Rankin Scale [mRS]) and severe gait disturbance were evaluated at 3 and 12 months following shunt surgery, and the tap test was also conducted. Age-adjusted and multivariate relative risks were calculated using Cox proportional-hazards regression.


Of 83 patients with iNPH, 45 (54%) improved by 1 point on the mRS and 6 patients (7%) improved by ≥ 2 points at 3 months following surgery. At 12 months after surgery, 39 patients (47%) improved by 1 point on the mRS and 13 patients (16%) improved by ≥ 2 points. On the gait domain of the iNPH grading scale (iNPHGS), 36 patients (43%) improved by 1 point and 13 patients (16%) improved by ≥ 2 points at 3 months following surgery. Additionally, 32 patients (38%) improved by 1 point and 14 patients (17%) by ≥ 2 points at 12 months following surgery. In contrast, 3 patients (4%) and 2 patients (2%) had worse symptoms according to the mRS or the gait domain of the iNPHGS, respectively, at 3 months following surgery, and 5 patients (6%) and 3 patients (4%) had worse mRS scores and gait domain scores, respectively, at 12 months after surgery. Patients with severe preoperative mRS scores had a 4.7 times higher multivariate relative risk (RR) for severe mRS scores at 12 months following surgery. Moreover, patients with severe gait disturbance prior to shunt surgery had a 46.5 times greater multivariate RR for severe gait disturbance at the 12-month follow-up. Patients without improved gait following the tap test had multivariate RRs for unimproved gait disturbance of 7.54 and 11.2 at 3 and 12 months following surgery, respectively. Disease duration from onset to shunt surgery was not significantly associated with postoperative symptom severity or unimproved symptoms.


Patients with iNPH should receive treatment before their symptoms become severe in order to achieve an improved quality of life. However, the progression of symptoms varies between patients so specific timeframes are not meaningful. The authors also found that tap test scores accurately predicted shunt efficacy. Therefore, indications for shunt surgery should be carefully assessed in each patient with iNPH, considering the relative risks and benefits for that person, including healthy life expectancy.