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ABSTRACT: BACKGROUND: It has been suggested that antiplatelet or anticoagulant drugs elevate the rate of intracerebral hemorrhage (ICH) in patients with cerebral microbleeds (MBs). To investigate the mechanism by which antiplatelet drugs or warfarin may contribute to deep ICH occurrences in patients with deep MBs, we prospectively analyzed deep ICH occurrences in 807 consecutive patients (351 females and 456 males; mean age ± standard deviation 69.8 ± 12.0 years) who were admitted to our hospital with strokes. METHODS: Occurrence-free rate curves were generated using the Kaplan-Meier method; deep ICH occurrence-free rates were compared using the log-rank test. The follow-up period was 0.5 to 71 months (mean ± standard deviation 31.6 ± 22.2 months). RESULTS: In patients with deep MBs, the rates (1.0%/year; 6 ICHs in 180 patients) of deep ICH occurrence associated with antiplatelet drugs were not significantly greater than that without the drugs (1.0%/year; 6 ICHs in 167 patients; P = .977). The incidence of deep ICHs associated with warfarin use was not significantly greater than that without warfarin use. CONCLUSIONS: Multivariate analysis revealed that the use of antiplatelet drugs or warfarin did not significantly influence the occurrence of deep ICH in patients with deep MBs. Antiplatelet drugs or warfarin did not significantly elevate the rate of deep ICHs in stroke patients with pre-existing deep MBs.
Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association 09/2012;
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ABSTRACT: Symptomatic spinal arachnoid cyst is a rare disease and the pathophysiology causing spinal cord symptoms has not been well clarified.
The authors report three symptomatic cases of spinal arachnoid cyst at the thoracic level. These patients, aged from 70 to 73 years, showed progressive gait disturbance for a few months before admission. Phase-contrast cine magnetic resonance imaging demonstrated significant compression at the rostral side of the cyst during the diastolic phase of the cardiac cycle. Intraoperative ultrasonography demonstrated that the maximum expansion of the cyst and compression of the dorsal spinal cord occurred when the cerebrospinal fluid moved rostrally during diastole. All patients showed good improvement of their symptoms after surgical removal of the arachnoid cyst.
This report proposes the pathophysiology that the pulsatile enlargement of the arachnoid cyst during diastolic cardiac phase can be an important factor for deterioration of spinal cord symptoms.
Acta Neurochirurgica 12/2009; 152(7):1245-9. · 1.52 Impact Factor
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ABSTRACT: A significant variety in morphology of conus lipomas may underlie differences in clinical presentation of the patients and controversy in surgical management. We retrospectively studied 58 patients with conus lipomas at our institutions. The purpose of this study was to infer the clinical course from the radiological findings and to provide information for decision-making in planning for surgical treatment.
The patients underwent untethering surgery between 1984 and 2005. There were 35 transitional and 23 dorsal lipomas. The age at surgery ranged from 1 month to 50 years (median, 4 yr). Preoperative clinical history, radiological findings, and postoperative results were analyzed.
Fifteen patients were asymptomatic, and 43 patients were symptomatic preoperatively. Twenty-one patients presented with motor deficits of the lower extremities. In seven patients, motor deficits appeared early, before 1 year of age. Massive lipomas compressing the cord or herniation of the spinal cord into the subcutaneous tissue were characteristic findings of such early deterioration. Motor deficits were present in 73% of patients with lipomas extending to the lumbar level, whereas 88% of patients with lipomas confined to the sacral level had only urinary deficits. During a mean postoperative follow-up period of 7.9 years, 4 (27%) of the 15 asymptomatic patients developed urinary and/or motor deficits, and 12 (28%) of the 43 symptomatic patients showed further neurological deterioration.
This study demonstrates that the location and morphology of conus lipomas influence the neurological presentation of the patients. Early prophylactic surgery is a reasonable treatment option if early deterioration is predicted by imaging studies.
Neurosurgery 10/2008; 63(3):546-51; discussion 551-2. · 2.79 Impact Factor
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ABSTRACT: The pathophysiology of syringomyelia in Chiari type 1 malformations has not been clarified. Oedema-like spinal-cord swelling was recently reported in several pathological conditions, including Chiari type 1 malformations as a pre-syrinx state. However, the role of the pre-syrinx state in the development of syringomyelia is unknown. The purpose of this study is to investigate the parenchymal changes of the spinal cord in syringomyelia associated with Chiari type 1 malformations.
Pre- and postoperative MRI findings in 14 patients who underwent foramen magnum decompression in our institute were reviewed. The analysis was focused on differences in visualisation of the syrinx between T1- and T2-weighted images and abnormal parenchymal signal changes. There were 6 men and 8 women, aged from 6 to 79 years. No patients showed hydrocephalus.
Twelve patients had large and expansive syrinx, whereas 2 patients showed small syrinx confined to the centre of the spinal cord. T2-weighted images displayed significantly larger intramedullary abnormal signal areas. Nine patients showed parenchymal hyperintensity areas around the enlarged central canal or base of the posterior white columns adjacent to the syringomyelic cavity. Such parenchymal hyperintensity areas markedly diminished with reduction of the syrinx after surgery and were considered to be interstitial oedema.
From this study, the interstitial oedema of the spinal cord commonly accompanies syringomyelia with Chiari type 1 malformations. Accumulation of the extracellular fluid due to disturbed absorption mechanisms may play an important role in the pathophysiology of syringomyelia associated with Chiari type 1 malformations.
Journal of neurology, neurosurgery, and psychiatry 05/2008; 79(10):1153-8. · 4.87 Impact Factor
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ABSTRACT: Microangiopathy, a disorder often related to hypertension, is an important cause of deep intracerebral hematoma (ICH). The microangiopathy is associated with dot-like low-intensity spots (a dot-like hemosiderin spot: dotHS) on gradient-echo T2*-weighted MR images that have been histologically diagnosed as old microbleeds. The locations of dotHS are consistent with deep ICH.
To investigate how dotHS or other risk factors contribute to nonhypertensive deep ICH, the number and location of dotHSs, as well as other risk factors were examined in 213 deep ICH patients (106 males, 107 females, age: 37-94 (65.8 +/- 11.2) years) consecutively admitted to Hakodate Municipal Hospital. Patients were divided into two subgroups according to the presence or absence of hypertension. DotHSs were also divided into deep and subcortical dotHS and investigated independently. Odds ratios (ORs) were estimated from logistic regression analyses. Furthermore, nonhypertensive ICH patients were compared with nonhypertensive healthy volunteers matched for age and sex.
No risk factors were identified in the 31 nonhypertensive deep ICH patients that differed from those found in the 182 hypertensive deep ICH patients. Deep dotHS > or = 1 (OR: 25.5; 95% CI: 4.76-137; P = .0002), subcortical dotHS > or = 1 (OR: 9.0; 95% CI: 1.79-44.9; P = .046), diabetes mellitus (OR: 9.0; 95% CI: 1.53-52.3; P = .015), and smoking (OR, 9.6; 95% CI; 1.8-49.8, P = .007) significantly elevated the risk of nonhypertensive ICH, compared to the healthy volunteers.
Our findings suggest that deep and subcortical dotHSs may be risk factors for the development of non-hypertensive deep ICH.
Journal of Neuroimaging 01/2006; 16(1):39-46. · 1.51 Impact Factor
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ABSTRACT: Hemosiderin degenerated from intracerebral hematoma (ICH) can be visualized as low intensity on gradient-echo T2*-weighted (T2*-w) MRI, which is sensitive for hemosiderin. We studied the factors associated with the hemosiderin deposition on T2*-w MRI after ICH.
We analyzed T2*-w MRIs in 72 outpatients with past ICH (46 males, 26 females, 28-89 (60.0 +/- 9.8) years old) consecutively came to our hospital. The odds ratio (OR) for the apparent thickness > or = 2.5 mm of low intensity surrounding ICH cavity was estimated, using the time after the onset of ICH (17 weeks - 26 years), and other factors.
All of old ICHs were visible as low intensities on T2*-w MRI. Multivariate logistic regression analysis revealed that an elevated ratio of the apparent thickness > or = 2.5 mm of hemosiderin was found for the patients with time > or =5 years between T2*-w MRI and the onset (odds ratio (OR): 0.24, 95% confidence interval (CI): 0.06-0.99), intraventricular or subarachnoid hemorrhage related to ICH (OR: 0.16, 95% CI: 0.03-0.77), and the diameter of ICH > or =2 cm (OR: 33.7, 95% CI: 4.6-245).
Though small sample size limited the power of analyses, our findings suggest that the amount of hemosiderin deposition after ICH may be associated with the time after the onset, intraventricular or subarachnoid hemorrhage related to ICH, and the diameter of ICH.
No shinkei geka. Neurological surgery 12/2005; 33(12):1177-81. · 0.13 Impact Factor
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ABSTRACT: Stent placement for the treatment of carotid artery stenosis may cause hemodynamic instability that induces ischemic complications for patients with bilateral carotid lesions. We carried out this study to define predictors of persistent hypotension after carotid stenting.
Thirty-three lesions in 31 consecutive patients (mean age, 69.2 +/- 8.6 yr) who underwent stent deployment for carotid stenosis were studied. Fourteen lesions were treated with Easy Wall stents (Boston Scientific, Tokyo, Japan) and 19 lesions were treated with Smart stents (Johnson & Johnson, Warren, NJ). We reviewed preoperative angiograms and ultrasonograms of the carotid artery and analyzed the predictive factors of postprocedural prolonged hypotension (systolic blood pressure < 90 mm Hg and periods > 3 h).
Postprocedural hypotension was observed in 14 lesions (42.4%), of which medical treatment was necessary in seven (21.2%). A distance between carotid bifurcation and maximum stenotic lesion (< or = 10 mm; P = 0.0028) and type of stenosis (eccentric; P = 0.0287) on angiogram and fibrous plaque morphological features (P = 0.0008) and calcifications at carotid bifurcation (P = 0.0004) on ultrasonograms were determined to be independent risk factors of postprocedural hypotension. We introduced a scoring system for predicting prolonged hypotension that included factors such as the distance from carotid bifurcation to maximum stenotic lesion (< or = 10 mm), type of stenosis (eccentric), plaque morphological features (echogenic), and calcification at carotid bifurcation. The score was determined by adding one point for each of these factors. Three points or more on this score strongly suggested a high risk of prolonged hypotension.
Our scoring system, which includes angiographic and ultrasonographic findings, may be a good index for the prediction of prolonged hypotension after carotid stenting and may contribute to the reduction of periprocedural ischemic events.
Neurosurgery 10/2005; 57(3):472-7; discussion 472-7. · 2.79 Impact Factor
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ABSTRACT: Dotlike hemosiderin spots ongradient-echo T2(*)-weighted magnetic resonance imaging of the brain have been histologically diagnosed as old microbleeds associated with small vessel disease (SVD). The authors hypothesize that the presence of many dotHSs may be correlated with the fragility of small vessels and the recurrence of SVD, including lacunar infarction and deep intracerebral hemorrhage (ICH).
To investigate how dotHSs are related to past history of SVD, the number of subcortical or deep dotHSs was investigated in 146 patients with lacunar infarctions (95 men, 51 women, age 38 to 90 [66.6+/-9.4] years). They were divided into 2 subgroups according to history of deep ICHs or lacunar infarctions. The odds ratio (OR) for past history was estimated from logistic regression analyses with the number of subcortical or deep dotHSs as well as other factors.
Of 146 patients with lacunar infarctions, 11 had past symptomatic ICHs and 19 had past symptomatic lacunar infarctions. An elevated rate of history of ICH was found for lacunar infarction patients with many deep dotHSs (>or=3; OR, 9.1; 95% confidence interval, 1.6-51, P=.015). However, history of lacunar infarction was not significantly associated with the number of subcortical or deep dotHSs.
Our findings suggest that many deep dotHSs on T2(*)-weighted magnetic resonance imaging may be correlated with deep ICH-lacunar infarction type of SVD recurrence but not lacunar infarction-lacunar infarction type.
Journal of Neuroimaging 05/2005; 15(2):157-63. · 1.51 Impact Factor
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ABSTRACT: We present the case of a 20-year-old female who underwent foramen magnum decompression and laminectomy of C1-C3 as well as incision of only the outer layer of the dura, for her symptomatic Chiari malformation (type 1) with syringomyelia, at the age of 9 years. She required additional surgery with removal of regenerated bone and dural plasty for the remaining and recurrent stenosis. The remaining stenosis may have been caused by the use of a technique without dural plasty and insufficient decompression of the bony structure. Further, the regeneration of C1 lamina could have been responsible for the recurrent stenosis. Her symptoms, which included gait disturbance, hypesthesia, excessive sweating, and nocturnal enuresis, manifested themselves when she was at the age of 2 years and progressed since that time. These symptoms didn't improve after the first surgery. However, after the second surgery, the gait disturbance and nocturnal enuresis were partially resolved. It is rare for new bone generation to necessitate reoperation. However, it should be noticed that careful follow-up is important after decompressive surgery for Chiari malformation in young patients.
No shinkei geka. Neurological surgery 04/2005; 33(3):257-60. · 0.13 Impact Factor
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PhD Toshio Imaizumi MD,
PhD Toshimi Honma MD,
Yoshifumi Horita MD,
PhD Satoshi Iihoshi MD,
Tatsufumi Nomura MD,
Kazuhisa Yoshifuji MD,
PhD Jun Niwa MD,
Toshio Imaizumi,
Toshimi Honma,
Yoshifumi Horita,
Satoshi Iihoshi,
Tatsufumi Nomura, Kazuhisa Yoshifuji,
Jun Niwa
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ABSTRACT: Background and Purpose. Dotlike hemosiderin spots ongradient-echo T2*-weighted magnetic resonance imaging of the brain have been histologically diagnosed as old microbleeds associated with small vessel disease (SVD). The authors hypothesize that the presence of many dotHSs may be correlated with the fragility of small vessels and the recurrence of SVD, including lacunar infarction and deep intracerebral hemorrhage (ICH). Methods. To investigate how dotHSs are related to past history of SVD, the number of subcortical or deep dotHSs was investigated in 146 patients with lacunar infarctions (95men, 51 women, age 38 to 90 [66.6 ± 9.4] years). They were divided into 2 subgroups according to history of deep ICHs or lacunar infarctions. The odds ratio (OR) for past history was estimated from logistic regression analyses with the number of subcortical or deep dotHSs as well as other factors. Results. Of 146 patients with lacunar infarctions, 11 had past symptomatic ICHs and 19 had past symptomatic lacunar infarctions. An elevated rate of history of ICH was found for lacunar infarction patients with many deep dotHSs (≥3; OR, 9.1; 95% confidence interval, 1.6–51, P= .015). However, history of lacunar infarction was not significantly associated with the number of subcortical or deep dotHSs. Conclusions. Our findings suggest that many deep dotHSs on T2*-weighted magnetic resonance imaging may be correlated with deep ICH—lacunar infarction type of SVD recurrence but not lacunar infarction—lacunar infarction type.
Journal of neuroimaging: official journal of the American Society of Neuroimaging 03/2005; 15(2):157 - 163. · 1.72 Impact Factor
