Biomedical subjects

Nobuhiko Miyazawa

Publications and source records attributed to Nobuhiko Miyazawa.

11 recordsLinked to original sources

PubMed2006

Diffuse idiopathic skeletal hyperostosis associated with risk factors for stroke: a case-control study.

STUDY DESIGN: The incidence of risk factors for cerebrovascular diseases was investigated in patients with diffuse idiopathic skeletal hyperostosis (DISH) and patients with cervical spondylosis. OBJECTIVES: To investigate the association between DISH and cerebrovascular disease. SUMMARY OF BACKGROUND DATA: DISH is a common skeletal disease mainly affecting the anterior and lateral spinal longitudinal ligaments. The principal clinical features are nonradicular pain, stiffness, dysphagia (cervical portion), and associated ossification of the posterior longitudinal ligament. METHODS: Age- and sex-matched patients were divided into three groups: 45 patients with DISH, 45 patients with cervical spondylosis Grade I and II, and 45 patients with cervical spondylosis Grade III and IV. Anthropometric, laboratory, and magnetic resonance (MR) imaging findings were analyzed. RESULTS: The values of uric acid (P = 1.60 x 10) and alkaline phosphatase (P = 2.00 x 10) were significantly greater in patients with DISH than in the other groups. Patients with DISH had a significantly higher incidence of ossification of the posterior longitudinal ligament (P = 5.21 x 10). Stiffness was significantly more common in patients with DISH and patients with spondylosis Grade III and IV than in patients with spondylosis Grade I and II (P = 0.000232). The incidence of infarction on MR imaging was significantly higher in patients with DISH than in the other groups (P = 0.0120). The incidence of stenosis or occlusion of a major cerebral artery on MR angiography was significantly higher in patients with DISH than in the other groups (P = 0.00264). CONCLUSIONS: DISH is associated with increased incidences of risk factors for stroke and cerebrovascular disease.

Aged↗

PubMed2006

Risk factors for growth of unruptured intracranial aneurysms: follow-up study by serial 0.5-T magnetic resonance angiography.

OBJECTIVE: The independent risk factors for aneurysm growth were retrospectively investigated in 130 patients with unruptured aneurysms who were followed up by 0.5-T serial magnetic resonance angiography with stereoscopic images. METHODS: Age, sex, site of aneurysm, size of aneurysm, multiplicity of aneurysms, type of circle of Willis, length of follow-up period, cerebrovascular event, hypertension, diabetes, hyperlipidemia, smoking habit, and family history of subarachnoid hemorrhage were investigated using multiple logistic analysis. RESULTS: Fourteen patients (16 aneurysms) among the 130 patients (159 aneurysms) showed aneurysm growth (10.8%) during follow-up of 10 to 69 months (mean 29.3 +/- 10.5 mo). Multiple logistic analysis disclosed that location on the middle cerebral artery (odds ratio [OR] 0.08, P < 0.01), multiplicity of aneurysms (OR 68.5, P < 0.01), aneurysm size of 5 mm or larger (OR 1.17, P = 0.05), and family history of subarachnoid hemorrhage (OR 10.9, P < 0.01) were independent risk factors. CONCLUSION: Location on the middle cerebral artery, multiplicity, aneurysm size of 5 mm or larger, and family history of subarachnoid hemorrhage are independent risk factors for aneurysm growth. These results may help to determine the treatment choice for unruptured aneurysms.

Aged↗

PubMed2005

COL6A1, the candidate gene for ossification of the posterior longitudinal ligament, is associated with diffuse idiopathic skeletal hyperostosis in Japanese.

STUDY DESIGN: Genetic screening of collagen 6A1 gene (COL6A1) in patients with diffuse idiopathic skeletal hyperostosis (DISH) recruited in Japan and the Czech Republic. OBJECTIVE: To investigate allelic associations between DISH and nucleotide variants of COL6A1. SUMMARY OF BACKGROUND DATA: DISH is a skeletal hyperostotic disease characterized by ligamentous ossification of the anterolateral side of the spine. Ossification of the posterior longitudinal ligament (OPLL) is a related disorder with DISH, and COL6A1 was identified as a susceptibility gene to OPLL. COL6A1 was examined for susceptibility in DISH patients from Japan and the Czech Republic. METHODS: Seven single nucleotide polymorphisms of COL6A1 were genotyped by direct sequencing. The allele frequencies were compared between 97 Japanese DISH patients and 298 Japanese controls, and between 96 Czech DISH patients and 96 Czech controls by chi2 test. RESULTS: The intron 32 (-29) single nucleotide polymorphisms of COL6A1 was significantly associated with the Japanese DISH patients (chi2 = 9.33; P = 0.0022), but not with the Czech DISH patients. CONCLUSIONS: Because COL6A1 could be a susceptibility to the occurrence of DISH and OPLL in the Japanese population, we consider that COL6A1 could be responsible for the hyperostotic state, leading to ectopic bone formation in the spinal ligament.

Aged↗

PubMed2005

Perfusion CT investigation of chronic internal carotid artery occlusion: comparison with SPECT.

This study investigated the usefulness of perfusion computed tomography (CT) for the evaluation of patients with chronic internal carotid artery (ICA) occlusion by comparing the findings with those of iodine-123 iodoamphetamine ([(123)I]IMP) single photon emission computed tomography (SPECT). Twenty five patients with chronic ICA occlusion were investigated on the same day by perfusion CT to measure the cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transient time (MTT), and [(123)I]IMP SPECT to measure the regional CBF, significant correlations were observed between regional CBF measured by SPECT and CBF measured by perfusion CT (r = 0.659, R(2) = 0.434, p < 0.001), regional CBF and CBV (r = -0.406, R(2) = 0.165, p < 0.001) and regional CBF and MTT (r = -0.592, R(2) = 0.350, p < 0.001). Significant correlations were also observed between CBF and CBV (r = -0.153, R(2) = 0.023, p < 0.001), CBF and MTT (r = -0.580, R(2) = 0.337, p < 0.001) and MTT and CBV (r = 0.763, R(2) = 0.582, p < 0.001). Perfusion CT is useful to evaluate the hemodynamic state of patients with chronic major cerebral artery occlusive disorders.

Aged↗

PubMed2004

Supernumerary phantom limbs associated with left hemispheric stroke: case report and review of the literature.

OBJECTIVE AND IMPORTANCE: Supernumerary phantom limb (SPL) is extremely rare. Literature reports noted 17 cases that occurred after right cerebral hemispheric stroke and 2 cases that occurred after left cerebral hemispheric stroke, but without imaging diagnoses. CLINICAL PRESENTATION: A 45-year-old male patient complained of SPLs on the right side after recurrent left thalamic hemorrhage. Computed tomography and magnetic resonance imaging demonstrated the lesion causing the left hemispheric stroke. INTERVENTION: The patient was treated conservatively. Computed tomographic scans demonstrated that the lesion had disappeared by 15 days after admission. The sensation of SPLs disappeared after 28 days. CONCLUSION: SPL may occur among patients with left hemispheric stroke, especially those with lesions in the thalamus, spastic paresis on the right side immediately after stroke, and psychiatric disorders such as alcohol and tobacco intoxication.

Body Image↗

PubMed2003

[A case of multiple mycotic intracranial aneurysms].

A patient with multiple mycotic aneurysms associated with infective endocarditis is reported. A 45-year-old man was admitted on February 16, 2001 under the diagnosis of infective endocarditis. After alpha-streptococcus was identified by a blood culture, he was treated with high doses of antibiotics. However, 2 weeks after admission, he suddenly suffered from headache and mild left hemiparesis. A CT showed a parenchymal hematoma in the right parietal lobe. Cerebral angiography demonstrated aneurysms of the bilateral middle cerebral artery and the left posterior cerebral artery. At first, we trapped and resected the ruptured right middle cerebral aneurysm. After the surgery, we tried to treat two unruptured aneurysms by endovascular treatment. During the provocation test for the posterior cerebral artery, the arterial wall was perforated by a guide wire. The parent artery was occluded by coils at this site. Although the aneurysm was still filled by retrograde blood flow, it finally disappeared six months after treatment. The left middle cerebral artery aneurysm could not be treated because the provocation test showed cognitive deficits. The patient recovered from infective endocarditis after four-months of antibiotic therapy; and the unruptured aneurysm had not changed in size for 11 months. Recently, the outcome of patients with intracranial mycotic aneurysm is improved by development of multimodality management. Especially, endovascular therapy may become an effective treatment for unruptured aneurysms, but it is necessary to take risks, such as arterial perforation into consideration.

Aneurysm, Infected↗

PubMed2003

[Clinical and radiological study of ossification of the anterior longitudinal ligament in the cervical spine].

Twenty-seven patients with ossification of the anterior longitudinal ligament (OALL) in diffuse idiopathic skeletal hyperostosis (DISH) in the cervical region were diagnosed among 2000 individuals during 10 months and analyzed clinically and radiologically by two neurosurgeons. Sex distribution was 20 men and 7 women with ages ranging from 57 to 82 years (average: 72.3 y.o.). Main signs and symptoms were dysesthesia of the upper extremities, stiff neck, dizziness and dysphagia (33%). Three patients had diabetes mellitus, 14 had hypertension, and 15 had hyperuremia. Ossification of the posterior longitudinal ligament (OPLL) co-existed in 18 patients (66%). Number of vertebral bodies with cervical OALL ranged from 4 to 6 (average: 4.8) and thickness of ossification of the anterior longitudinal ligament was from 2 to 6 (average: 3.1) mm. Originally we divided OALL in the cervical region into 3 types, nodular-type; 16 cases, continuous-type; 7 cases, and mixed-type; 4 cases. Small OPLL can be diagnosed by either cervical CT or myelo-CT. DISH is thought to be a benign clinical entity, but patients with OALL in DISH, accompanied by OPLL and those accompanied by dysphasia are frequently encountered and sometimes may be treated surgically.

Aged↗

PubMed2002

Optimal inversion time for acquiring flow-sensitive alternating inversion recovery images to quantify regional cerebral blood flow.

The purpose of this study was to correlate regional cerebral blood flow (rCBF) measured by I-123-IMP and flow-sensitive alternating inversion recovery (FAIR) studies with different inversion time (TI) values to find out the optimum TI that gives comparable rCBF and images on FAIR study. Nine patients with symptoms and signs of internal carotid or major cerebral arterial stenosis were enrolled in this study. Both I-123-IMP single photon emission computed tomography (SPECT) and FAIR images were acquired in all patients. Single-slice FAIR images (with different TI values) were acquired using a 1.5-T MRI unit. The rCBF was calculated from all I-123-IMP and FAIR images. Receiver operating characteristics (ROC) analysis was performed to detect hypoperfused segments on FAIR images. The rCBF calculated from FAIR and I-123-IMP studies were compared and correlated with each other. The ROC analysis showed no significant differences among the readers or TI values, but a trend of higher sensitivity, specificity, and accuracy was observed with TI of 1400 ms. The rCBF values of FAIR and I-123-IMP studies significantly correlated with each other. The FAIR images with TI value of 1400 ms gave more comparable CBF. A TI value of 1400 ms might be optimum for 1.5-T MR strength to get high quality FAIR images and comparable CBF.

Aged↗

PubMed2002

Surgical management of aneurysms of the bifurcation of the internal carotid artery.

Internal carotid artery (ICA) bifurcation aneurysms are rare and easily bleed in younger patients, but are difficult to treat surgically, due to perforators surrounding and adherent to the aneurysm. A series of 25 patients treated by clipping under the operating microscope are analyzed and compared with previous cases. Twenty-five patients, 11 men and 14 women (mean age 51 years), were treated by the same neurosurgeon. Seventeen patients presented with subarachnoid hemorrhage (Hunt & Kosnik Grade I in three, II in five, III in two, IV in seven), five with unruptured ICA bifurcation aneurysms, and three with unruptured ICA bifurcation aneurysms but another ruptured aneurysm. There were 23 small, one large, and one giant ICA bifurcation aneurysms. The projection was superior in 12, anterior in seven, and posterior in six cases. Pterional approach was employed for all cases. Outcomes were evaluated at discharge with the Glasgow Outcome Scale. Favorable outcomes (good recovery (GR) and moderate disability (MD)) were obtained in ten of 17 patients with ruptured ICA bifurcation aneurysm. Favorable outcomes were significantly greater in Grades I and II (three in I, four in II) than in Grades III and IV (one in III, two in IV; P=0.0498). Seven of eight patients with unruptured ICA bifurcation aneurysm had favorable outcomes. Temporary clipping and projection of the aneurysm did not affect the outcome. Causative factors of unfavorable outcomes were primary brain damage in cases of small and large aneurysms and perforator damage in the case of giant aneurysm. Poor clinical grade and vasospasm are the causative factors of poor outcome in patients with ruptured ICA bifurcation aneurysm. Preservation of perforators is crucial in cases of giant aneurysm. Clipping of unruptured ICA bifurcation aneurysms is recommended since they tend to bleed at a lower age than other aneurysms.

Brain↗

PubMed2002

Velocity-coded colour magnetic resonance angiography and perfusion-weighted magnetic resonance imaging for the evaluation of extracranial-to-intracranial arterial bypass surgery.

BACKGROUND AND PURPOSE: Velocity-coded colour magnetic resonance angiography (VCCMRA) and perfusion magnetic resonance imaging (pMRI) were evaluated as methods for investigating the efficacy of extracranial-to-intracranial arterial bypass (EC-IC bypass) by comparing the findings of VCCMRA and those of cerebral angiography and by measuring the improvement ratio after EC-IC bypass by pMRI compared to that by single photon emission computed tomography (SPECT) using the autoradiographic technique. METHODS: Thirteen patients who underwent VCCMRA, angiography, SPECT, and pMRI before and after surgery were analyzed. Findings of VCCMRA were compared to those of angiography. Improvement ratio was calculated compared to the cerebellum for cerebral blood volume, mean transit time (MTT), and regional cerebral blood flow (rCBF) as measured by pMRI and quantitative SPECT. RESULTS: Findings of VCCMRA were in good agreement with those of angiography and clearly showed the direction of bypass flow. No statistically significant correlation was observed between the improvement ratios in CBF in the hemisphere and middle cerebral artery territory on the surgical and non-surgical sides and in rCBF in the same regions of interest (ROIs) (r=-0.574, 0.09). However, a statistically significant correlation was observed between the cerebrovascular reserve capacity (CVRC) in the hemisphere on the surgical side and in MTT in the same ROIs (r=0.955, P<0.001). CONCLUSION: VCCMRA may clearly show the direction of flow in the EC-IC bypass. MIT measured by pMRI may indicate the postoperative state of CVRC. These techniques could replace angiography and positron emission tomography or SPECT in patients undergoing EC-IC bypass.

Adult↗

PubMed2002

Quantitative measurement of regional cerebral blood flow with flow-sensitive alternating inversion recovery imaging: comparison with [iodine 123]-iodoamphetamin single photon emission CT.

BACKGROUND AND PURPOSE: Flow-sensitive alternating inversion recovery (FAIR) MR imaging is a technique for depicting cerebral perfusion without contrast enhancement. Our purpose was to determine whether quantification at FAIR imaging can be used to assess regional cerebral blood flow (rCBF) in a manner similar to [iodine 123]-iodoamphetamin ((123)I-IMP) single photon emission CT (SPECT). METHODS: Nine patients with internal carotid or major cerebral arterial stenosis underwent (123)I-IMP SPECT and FAIR imaging (single section, different TIs, 1.5 T) at rest and after acetazolamide (Diamox) stress. FAIR and (123)I-IMP rCBF values were compared and correlated. Receiver operating characteristic analysis was conducted to detect hypoperfused segments on FAIR images. RESULTS: rCBF values of normally perfused segments were 41.53 and 51.91 mL/100 g/min for pre- and post-acetazolamide (123)I-IMP studies, respectively. Corresponding values for pre- and post-acetazolamide FAIR images, respectively, were 46.64 and 59.60 mL/100 g/min with a TI of 1200 milliseconds and 53.23 and 68.17 mL/100 g/min with a TI of 1400 milliseconds. (123)I-IMP and FAIR results were significantly correlated, with both pre- and post-acetazolamide images. Sensitivity (86%) in detecting hypoperfused segments was significantly higher with post-acetazolamide images (TI, 1400 milliseconds), and specificity (82-85%) and accuracy (80-82%) were higher with all pre- and post-acetazolamide images (all TIs). CONCLUSIONS: The significant correlation, high specificity and accuracy in detecting hypoperfused segments, similar increases in flow on both post-acetazolamide images, and absence of the need for contrast enhancement suggest that FAIR imaging, like nuclear medicine study, is complementary to routine MR imaging in the assessment of cerebral perfusion.

Acetazolamide↗