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Kazuhiko Shiokawa, Junya Hanakita, Hideyuki Suwa, Masaaki Saiki, Masashi Oda and Motohiro Kajiwara

Object. A variety of factors may affect surgery-related outcome in patients with ossification of the ligamentum flavum (OLF) of the thoracic spine. The aim of this study was to determine these factors on the basis of preoperative clinical and radiological findings.

Methods. The authors treated 31 cases of symptomatic thoracic OLF between 1988 and 1999. The following factors were retrospectively studied: patient age, sex, morbidity level, initial symptoms, chief complaint, duration of symptoms, patellar reflex, Achilles reflex, computerized tomography (CT) finding, presence of intramedullary change determined by magnetic resonance imaging, coexistent spinal lesions, preoperative grade, and postoperative grade.

A decompressive laminectomy was performed in all cases. In 29 patients (94%) improved symptoms were demonstrated postoperatively. In terms of functional prognosis, the preoperative duration of symptoms was significantly shorter in the group of patients with excellent outcomes than in those with fair outcomes (p < 0.05).

No significant difference was observed in the correlation between other factors. To evaluate the degree of preoperative thoracic stenosis and the severity/extent of OLF-induced spinal compression, we used an original OLF CT scoring system. A score of excellent on the CT scale tended to indicate an excellent prognosis (p < 0.01).

Conclusions. Thoracic OLF frequently develops in the lower-thoracic spine in middle-aged men, and it is complicated by various spinal lesions in many cases. Early diagnosis and treatment are important for understanding the clinical symptoms and imaging diagnosis because the present findings suggest that a delay in diagnosis and treatment correlates with the functional prognosis postoperatively.

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Masaomi Koyanagi, Hitoshi Fukuda, Masaaki Saiki, Yoshihito Tsuji, Benjamin Lo, Toshinari Kawasaki, Yoshihiko Ioroi, Ryu Fukumitsu, Ryota Ishibashi, Masashi Oda, Osamu Narumi, Masaki Chin, Sen Yamagata and Susumu Miyamoto


Shunt-dependent hydrocephalus (SDHC) may arise after aneurysmal subarachnoid hemorrhage (aSAH) as CSF resorptive mechanisms are disrupted. Using propensity score analysis, the authors aimed to investigate which treatment modality, surgical clipping or endovascular treatment, is superior in reducing rates of SDHC after aSAH.


The authors’ multicenter SAH database, comprising 3 stroke centers affiliated with Kyoto University, Japan, was used to identify patients treated between January 2009 and July 2016. Univariate and multivariate analyses were performed to characterize risk factors for SDHC after aSAH. A propensity score model was generated for both treatment groups, incorporating relevant patient covariates to detect any superiority for prevention of SDHC after aSAH.


A total of 566 patients were enrolled in this study. SDHC developed in 127 patients (22%). On multivariate analysis, age older than 53 years, the presence of intraventricular hematoma, and surgical clipping as opposed to endovascular coiling were independently associated with SDHC after aSAH. After propensity score matching, 136 patients treated with surgical clipping and 136 with endovascular treatment were matched. Propensity score–matched cohorts exhibited a significantly lower incidence of SDHC after endovascular treatment than after surgical clipping (16% vs 30%, p = 0.009; OR 2.2, 95% CI 1.2–4.2). SDHC was independently associated with poor neurological outcomes (modified Rankin Scale score 3–6) at discharge (OR 4.3, 95% CI 2.6–7.3; p < 0.001).


SDHC after aSAH occurred significantly more frequently in patients who underwent surgical clipping. Strategies for treatment of ruptured aneurysms should be used to mitigate SDHC and minimize poor outcomes.