The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform
Jun Niwa - One of the best experts on this subject based on the ideXlab platform.
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subarachnoid Hemosiderin deposition after subarachnoid hemorrhage on t2 weighted mri correlates with the location of disturbed cerebrospinal fluid flow on computed tomography cisternography
Neurology India, 2008Co-Authors: Yoshifumi Horita, Toshio Imaizumi, Yuji Hashimoto, Jun NiwaAbstract:A 72-year-old male was admitted with subarachnoid hemorrhage associated with a ruptured cerebral aneurysm. The aneurysm was treated with clipping soon after radiological examination. Eight weeks after the treatment, the patient suffered from secondary hydrocephalus resulting from blockage of the subarachnoid space due to subarachnoid granulation. Previous pathological examination revealed the granulation was associated with Hemosiderin deposition. We investigated subarachnoid Hemosiderin deposition in this patient using T2*-weighted (T2*-w) magnetic resonance image (MRI), a sensitive method for Hemosiderin detection. computed tomography (CT) cisternography demonstrated that cerebrospinal fluid (CSF) flow was disturbed adjacent to sites of subarachnoid Hemosiderin deposition on T2*-w MRI. Placement of a ventriculo-peritoneal shunt contributed to neurological improvement. In this case, T2*-w MRI was an effective means of diagnosing the location of disturbed CSF flow associated with subarachnoid Hemosiderin deposition.
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detection of Hemosiderin deposition by t2 weighted mri after subarachnoid hemorrhage
Stroke, 2003Co-Authors: Toshio Imaizumi, Masahiko Chiba, Toshimi Honma, Jun NiwaAbstract:Background and Purpose— Subarachnoid hemorrhage (SAH) is very difficult to diagnose several months after its onset. We thus investigated subarachnoid Hemosiderin deposition well after SAH by T2*-weighted MRI, a sensitive method for Hemosiderin detection. Methods— To investigate how Hemosiderin deposition as confirmed by T2*-weighted MRI contributes to the determination of prior SAH and how the extent of Hemosiderin deposition is associated with a number of clinical factors, we retrospectively analyzed 58 patients >3 months after SAH associated with ruptured aneurysms. We also investigated 209 healthy volunteers as controls. Results— T2*-weighted MRI demonstrated subarachnoid Hemosiderin deposition in 72.4% of the SAH patients, whereas no deposition was seen in the healthy volunteer group. The Hemosiderin was preferentially deposited in the subarachnoid space near a ruptured aneurysm. Odds ratios (ORs) were estimated from logistic regression analyses correlating Hemosiderin deposition with other factors. A...
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analysis of dot like Hemosiderin spots using brain dock system
No shinkei geka. Neurological surgery, 2003Co-Authors: Yoshifumi Horita, Toshio Imaizumi, Jun Niwa, Kei Miyata, Junpei Yoshikawa, Takeshi Makabe, Ryo Moriyama, Kiyofumi Kurokawa, Masashi Mikami, Manami NakamuraAbstract:BACKGROUND AND PURPOSE: Dot-like low intensity spots (a dot-like Hemosiderin spot: dotHS) on T2*-weighted MR images (T2*WI), which is regarded as a sensitive method for Hemosiderin detection, have been histologically diagnosed as old microbleeds associated with microangiopathies. The clinical significance of the dotHS, however, is still under debate. Therefore, we investigated the factors associated with dotHS. METHODS: We investigated 209 healthy volunteers in our hospital (sex: 106 males, 103 females; age: 38 to 78 years old, mean age: 56.4 +/- 8.3 years old) using "Brain Dock", a formalized screening system for asymptomatic brain diseases. The Odds ratio (OR) was estimated from multiple logistic regression analyses using the dotHS and variables. RESULTS: T2*WI demonstrated dotHS in 7.7% of volunteers, and the mean number of dotHS was 0.16 +/- 0.78. The Hemosiderin was preferentially deposited in the basal ganglia and thalamus. Age > or = 65 years old (OR: 5.9; 95% confidence interval [CI]: 1.4-25.9; p = 0.02), hypertension (OR: 7.0; 95% CI: 1.4-34.7; p = 0.02), and headache (OR: 5.8; 95% CI: 1.4-24.6; p = 0.02) were all found to be independently associated with dotHS. CONCLUSIONS: The dotHS was significantly associated with several factors, including age, hypertension and headache.
Michael J Levy - One of the best experts on this subject based on the ideXlab platform.
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two year observational study of deferiprone in superficial siderosis
CNS Neuroscience & Therapeutics, 2018Co-Authors: Remi A Kessler, Xu Li, Kateryna Schwartz, Hwa Huang, Maureen A Mealy, Michael J LevyAbstract:Introduction Superficial siderosis is a rare, neurodegenerative disease caused by toxic accumulation of Hemosiderin on the surface of the brain and the spinal cord, most commonly from chronic subarachnoid hemorrhage.
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pilot safety trial of deferiprone in 10 subjects with superficial siderosis
Stroke, 2012Co-Authors: Michael J Levy, Rafael H LlinasAbstract:Background and Purpose—Superficial siderosis is a neurodegenerative disease caused by toxic accumulation of Hemosiderin on the surface of the brain and spinal cord for which there is no known effective treatment. Methods—Oral deferiprone, a lipid-soluble iron chelator with ability to cross the blood–brain barrier, at a dose of 30 mg/kg per day was tested for safety in an open pilot study in 10 subjects with superficial siderosis. Results—Over a 90-day period, deferiprone had no significant adverse effects on hematologic, liver, or neurological function. Ad hoc MRI assessments of the brain indicated a reduction in Hemosiderin deposition in some subjects. Conclusions—Deferiprone proved safe in this small population of superficial siderosis subjects. There was MRI evidence of reduced Hemosiderin deposition with deferiprone. Prospectively designed efficacy studies are necessary to determine the clinical efficacy of deferiprone in superficial siderosis.
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deferiprone reduces Hemosiderin deposits in the brain of a patient with superficial siderosis
American Journal of Neuroradiology, 2010Co-Authors: Michael J Levy, Rafael H LlinasAbstract:SUMMARY: A man with superficial siderosis showed improvement in symptoms and reduction in Hemosiderin by MR imaging following treatment with deferiprone, a lipid-soluble iron chelator.
Michael Mull - One of the best experts on this subject based on the ideXlab platform.
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Frequency and appearance of Hemosiderin depositions after aneurysmal subarachnoid hemorrhage treated by endovascular therapy
Neuroradiology, 2015Co-Authors: Bernhard Falter, Martin Wiesmann, Jessica Freiherr, Omid Nikoubashman, Michael MullAbstract:Introduction It is still unclear how often subarachnoid hemorrhage (SAH) leads to chronic Hemosiderin depositions. In this study, we aimed to determine the frequency of chronic Hemosiderin depositions after aneurysmal SAH in patients who did not undergo surgery. Furthermore, we analyzed typical MRI patterns of chronic SAH and sought to obtain information on the temporal course of MRI signal changes. Methods We retrospectively analyzed 90 patients who had undergone endovascular treatment for acute aneurysmal SAH. In all patients, initial CT studies and at least one T2*-weighted MRI obtained 6 months or later after SAH were analyzed for the presence and anatomical distribution of SAH or chronic Hemosiderin depositions. In total, 185 T2*-weighted MRI studies obtained between 2 days and 148 months after SAH were evaluated (mean follow-up 30.2 months). Results On MRI studies obtained later than 6 months after SAH, subpial Hemosiderin depositions were found in 50 patients (55.5 %). Most frequent localizations were the parenchyma adjacent to the frontal and parietal sulci and the insular cisterns. While the appearance of Hemosiderin depositions was dynamic within the first 3 months, no changes were found during subsequent follow-up. MR signal changes were not only conclusive with subarachnoid Hemosiderin depositions but in many cases also resembled those that have been associated with cortical hemosiderosis. Conclusions T2*-weighted MRI is an effective means of diagnosing prior SAH. Our study suggests that chronic Hemosiderin depositions can be found in a considerable number of patients after a single event of subarachnoid hemorrhage.
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frequency and appearance of Hemosiderin depositions after aneurysmal subarachnoid hemorrhage treated by endovascular therapy
Neuroradiology, 2015Co-Authors: Bernhard Falter, Martin Wiesmann, Jessica Freiherr, Omid Nikoubashman, Michael MullAbstract:Introduction It is still unclear how often subarachnoid hemorrhage (SAH) leads to chronic Hemosiderin depositions. In this study, we aimed to determine the frequency of chronic Hemosiderin depositions after aneurysmal SAH in patients who did not undergo surgery. Furthermore, we analyzed typical MRI patterns of chronic SAH and sought to obtain information on the temporal course of MRI signal changes.
Rafael H Llinas - One of the best experts on this subject based on the ideXlab platform.
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pilot safety trial of deferiprone in 10 subjects with superficial siderosis
Stroke, 2012Co-Authors: Michael J Levy, Rafael H LlinasAbstract:Background and Purpose—Superficial siderosis is a neurodegenerative disease caused by toxic accumulation of Hemosiderin on the surface of the brain and spinal cord for which there is no known effective treatment. Methods—Oral deferiprone, a lipid-soluble iron chelator with ability to cross the blood–brain barrier, at a dose of 30 mg/kg per day was tested for safety in an open pilot study in 10 subjects with superficial siderosis. Results—Over a 90-day period, deferiprone had no significant adverse effects on hematologic, liver, or neurological function. Ad hoc MRI assessments of the brain indicated a reduction in Hemosiderin deposition in some subjects. Conclusions—Deferiprone proved safe in this small population of superficial siderosis subjects. There was MRI evidence of reduced Hemosiderin deposition with deferiprone. Prospectively designed efficacy studies are necessary to determine the clinical efficacy of deferiprone in superficial siderosis.
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deferiprone reduces Hemosiderin deposits in the brain of a patient with superficial siderosis
American Journal of Neuroradiology, 2010Co-Authors: Michael J Levy, Rafael H LlinasAbstract:SUMMARY: A man with superficial siderosis showed improvement in symptoms and reduction in Hemosiderin by MR imaging following treatment with deferiprone, a lipid-soluble iron chelator.
Toshio Imaizumi - One of the best experts on this subject based on the ideXlab platform.
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subarachnoid Hemosiderin deposition after subarachnoid hemorrhage on t2 weighted mri correlates with the location of disturbed cerebrospinal fluid flow on computed tomography cisternography
Neurology India, 2008Co-Authors: Yoshifumi Horita, Toshio Imaizumi, Yuji Hashimoto, Jun NiwaAbstract:A 72-year-old male was admitted with subarachnoid hemorrhage associated with a ruptured cerebral aneurysm. The aneurysm was treated with clipping soon after radiological examination. Eight weeks after the treatment, the patient suffered from secondary hydrocephalus resulting from blockage of the subarachnoid space due to subarachnoid granulation. Previous pathological examination revealed the granulation was associated with Hemosiderin deposition. We investigated subarachnoid Hemosiderin deposition in this patient using T2*-weighted (T2*-w) magnetic resonance image (MRI), a sensitive method for Hemosiderin detection. computed tomography (CT) cisternography demonstrated that cerebrospinal fluid (CSF) flow was disturbed adjacent to sites of subarachnoid Hemosiderin deposition on T2*-w MRI. Placement of a ventriculo-peritoneal shunt contributed to neurological improvement. In this case, T2*-w MRI was an effective means of diagnosing the location of disturbed CSF flow associated with subarachnoid Hemosiderin deposition.
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detection of Hemosiderin deposition by t2 weighted mri after subarachnoid hemorrhage
Stroke, 2003Co-Authors: Toshio Imaizumi, Masahiko Chiba, Toshimi Honma, Jun NiwaAbstract:Background and Purpose— Subarachnoid hemorrhage (SAH) is very difficult to diagnose several months after its onset. We thus investigated subarachnoid Hemosiderin deposition well after SAH by T2*-weighted MRI, a sensitive method for Hemosiderin detection. Methods— To investigate how Hemosiderin deposition as confirmed by T2*-weighted MRI contributes to the determination of prior SAH and how the extent of Hemosiderin deposition is associated with a number of clinical factors, we retrospectively analyzed 58 patients >3 months after SAH associated with ruptured aneurysms. We also investigated 209 healthy volunteers as controls. Results— T2*-weighted MRI demonstrated subarachnoid Hemosiderin deposition in 72.4% of the SAH patients, whereas no deposition was seen in the healthy volunteer group. The Hemosiderin was preferentially deposited in the subarachnoid space near a ruptured aneurysm. Odds ratios (ORs) were estimated from logistic regression analyses correlating Hemosiderin deposition with other factors. A...
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analysis of dot like Hemosiderin spots using brain dock system
No shinkei geka. Neurological surgery, 2003Co-Authors: Yoshifumi Horita, Toshio Imaizumi, Jun Niwa, Kei Miyata, Junpei Yoshikawa, Takeshi Makabe, Ryo Moriyama, Kiyofumi Kurokawa, Masashi Mikami, Manami NakamuraAbstract:BACKGROUND AND PURPOSE: Dot-like low intensity spots (a dot-like Hemosiderin spot: dotHS) on T2*-weighted MR images (T2*WI), which is regarded as a sensitive method for Hemosiderin detection, have been histologically diagnosed as old microbleeds associated with microangiopathies. The clinical significance of the dotHS, however, is still under debate. Therefore, we investigated the factors associated with dotHS. METHODS: We investigated 209 healthy volunteers in our hospital (sex: 106 males, 103 females; age: 38 to 78 years old, mean age: 56.4 +/- 8.3 years old) using "Brain Dock", a formalized screening system for asymptomatic brain diseases. The Odds ratio (OR) was estimated from multiple logistic regression analyses using the dotHS and variables. RESULTS: T2*WI demonstrated dotHS in 7.7% of volunteers, and the mean number of dotHS was 0.16 +/- 0.78. The Hemosiderin was preferentially deposited in the basal ganglia and thalamus. Age > or = 65 years old (OR: 5.9; 95% confidence interval [CI]: 1.4-25.9; p = 0.02), hypertension (OR: 7.0; 95% CI: 1.4-34.7; p = 0.02), and headache (OR: 5.8; 95% CI: 1.4-24.6; p = 0.02) were all found to be independently associated with dotHS. CONCLUSIONS: The dotHS was significantly associated with several factors, including age, hypertension and headache.