Biomedical subjects

Kazunori Arita

Publications and source records attributed to Kazunori Arita.

At least 19 recordsLinked to original sources

PubMed2006

Survivin subcellular localization in high-grade astrocytomas: simultaneous expression in both nucleus and cytoplasm is negative prognostic marker.

OBJECTIVE: Subcellularly localized (nuclear and/or cytoplasmic) survivin has various functions, and correlates with prognosis of malignant tumors. However, there have been no reports about the significance of subcellularly localized survivin in high-grade astrocytomas. The aim of the present study was to examine the relationship between prognosis and subcellular localization of survivin in high-grade astrocytoma. METHODS: We immunohistochemically examined the pattern of subcellular localization of survivin expression (nuclear, cytoplasmic, or both) in 51 patients with high-grade astrocytoma (19 anaplastic astrocytomas; 32 glioblastomas). We statistically examined the relationship between survivin localization and prognosis, using multivariate analysis including other clinicopathological factors (age, sex, WHO grade, extent of resection, MIB-1 labeling index, and expression of p53 and epidermal growth factor receptor). RESULTS: All specimens stained positive for survivin: localized in nucleus only (nuclear-positive group), 10 cases (20%); localized in cytoplasm only (cytoplasmic-positive group), 23 cases (45%); simultaneous expression in nucleus and cytoplasm (nuclear-cytoplasmic group), 19 cases (35%). There was no significant difference in prognosis between the nuclear-positive group and cytoplasmic-positive group (P=0.796). However, the nuclear-cytoplasmic group had significantly shorter overall survival than the nuclear-positive group and the cytoplasmic-positive group (P<0.0001). CONCLUSIONS: We found that simultaneous expression of survivin in both the nucleus and cytoplasm is an important prognostic factor for high-grade astrocytoma. The present findings indicate that subcellular localization of survivin expression is a reliable prognostic factor for patients with this tumor.

Adolescent↗

PubMed2006

A pituitary abscess showing high signal intensity on diffusion-weighted imaging.

The utility of diffusion-weighted imaging (DWI) for the diagnosis of intracranial abscesses has already been established. However, the use of DWI for pituitary abscesses has not been previously reported. We present a case of postoperative pituitary abscess in which T1-weighted and T2-weighted magnetic resonance imaging (MRI) revealed a supra-sellar cystic mass, with the cyst contents showing high intensity on DWI. This case suggests that DWI is useful for the diagnosis of pituitary abscesses.

Aged↗

PubMed2006

Cytoplasmic, but not nuclear, p16 expression may signal poor prognosis in high-grade astrocytomas.

BACKGROUND: The negative consequences of the cytoplasmic localization of p16 in patients with high-grade astrocytomas, on their prognosis, was investigated. METHODS: p16 Expression was examined in 20 anaplastic astrocytoma and 42 glioblastoma patients by immunohistochemical analysis, and the relationship between both cytoplasmic and nuclear p16 expression and prognosis analyzed. RESULTS: The cytoplasmic expression of p16 statistically correlated with poor prognosis. On the other hand, no correlation was observed between p16 nuclear expression and patient survival. CONCLUSION: The cytoplasmic immunoreactivity of p16 appears to be an unfavorable prognostic indicator in high-grade astrocytoma patients. The localization of p16 expression should be determined when evaluating the prognosis of these patients.

Adolescent↗

PubMed2006

CT perfusion imaging in the syndrome of the sinking skin flap before and after cranioplasty.

The syndrome of the sinking skin flap (SSSF) has been described as one of the causes of neurological deficits after decompressive craniectomy We report a case of a 57-year-old woman with SSSF. Two years earlier, this patient, with no neurological deficits, underwent removal of the bone flap during treatment of an epidural abscess due to wound infection after a clipping operation for a ruptured aneurysm. The patient, who subsequently developed a sinking skin flap, gradually presented with gait disturbance and poor activity around 1 year before she came to our facility. On admission, neurological examination showed left hemiparesis and mild confusion. Cranioplasty with titanium mesh plate was performed. The cerebral blood flow (CBF) value in CT perfusion imaging in the symptomatic hemisphere increased from 23 to 31 cm3/100 g/min, and the value in the contralateral side increased from 37 to 41 cm3/100 g/min after cranioplasty. CT perfusion imaging after cranioplasty revealed the improvement of cerebral blood flow not only on the symptomatic side but also on the contralateral side. The patient recovered well and was discharged without hemiparesis and confusion 2 weeks after cranioplasty. As far as we know, this is the first reported case of SSSF examined with CT perfusion imaging before and after cranioplasty.

Cerebrovascular Circulation↗

PubMed2006

Natural course of incidentally found nonfunctioning pituitary adenoma, with special reference to pituitary apoplexy during follow-up examination.

OBJECT: The increase in the incidental detection of asymptomatic pituitary adenomas, known as "pituitary incidentalomas," led the authors to conduct a survey of the natural course of these lesions. METHODS: Forty-two patients with clinically nonfunctioning pituitary adenomas who had manifested no neurological or endocrinological disorders were monitored with magnetic resonance imaging studies. The follow-up period ranged from 10.8 to 168.2 months (mean +/- standard deviation, 61.9 +/- 38.2 months). The mean initial tumor size was 18.3 +/- 7 mm. In 21 patients, the tumor increased by at least 10% of its measured size on detection. This increase was first detected between 8.4 and 58.8 months (mean 31.8 +/- 17.6 months) after diagnosis. There was no correlation between the original tumor size, patient age, or the presence of intratumoral cysts and tumor growth. Symptoms were noted in 10 patients during follow up; in four, extensive tumor necrosis accompanied hemorrhage, leading to severe headache, acute ophthalmological symptoms, and panhypopituitarism, which was indicative of pituitary apoplexy. Transsphenoidal surgery was performed in 12 patients with enlarged tumors, including three with apoplexy. With the exception of one apoplectic patient, visual function was recovered in all who underwent surgery. All apoplectic patients continue to manifest hypopituitarism. CONCLUSIONS: In the course of 4 years, the size of the incidentalomas increased in 40% of 42 patients and became symptomatic in 20%. During the 5-year follow up, pituitary apoplexy developed in 9.5%. These findings may justify early intervention, especially in young individuals with incidentally found macroadenoma.

Adenoma↗

PubMed2006

[Late onset epilepsy associated with migration disorder: a case report].

We reported a 57-year-old female patient recently suffering from frequent seizures such as motionless staring and oral automatism. Electroencephalograms showed spikes in the right sphenoidal derivation and magnetic resonance images revealed an abnormal region, most likely related with a migration disorder such as a focal cortical dysplasia. She was diagnosed as mesiotemporal lobe epilepsy associated with a migration disorder. Seizure disappeared after medication therapy was done. No previous literature has described such a case, thus this is the first report of an epilepsy associated with migration disorder newly onset in a patient older than 50 years old.

Age of Onset↗

PubMed2006

Zygomatic osteotomy for resection of medial temporal cavernous angioma in dominant hemisphere after subdural grid electroencephalographic study.

We report the treatment of a patient suffering from intractable epilepsy caused by a large cavernous angioma in the hippocampus of his dominant hemisphere. Surgical removal of a lesion and epileptic focus located in the surrounding brain tissue significantly improves seizure conditions. However, total removal of a large cavernous angioma in the medial temporal structure of dominant hemisphere is occasionally difficult because of the depth of the lesion and its contiguity with eloquent brain structures. Furthermore, when an intracranial electrocorticogram with grid electrodes is adopted, swelling of soft tissue caused by the initial operation for the installation of the grid electrodes narrows the operative view obtained by conventional frontotemporal craniotomy. We added a zygomatic osteotomy to the operative procedure for the present patient, and this enabled us to push soft tissue down and away from the operative field to provide a wider operative corridor through which total removal of the lesion and epileptic focus was accomplished. The patient has had a favorable postoperative course without suffering any seizure for 4 years.

Adult↗

PubMed2005

Detection and differentiation of lactate and lipids by single-voxel proton MR spectroscopy.

The signals of lactate and lipids partially overlap in single-voxel proton MR spectroscopy (1HMRS), sometimes making them difficult to differentiate in clinical settings. Our aim in this study was to identify lactate and lipids by varying the echo time (TE). We expect that the accurate detection of lactate and lipids will have high diagnostic value in the diagnosis of brain tumors. Following our protocol, we obtained meaningful 1HMRS spectra from 213 patients, including 163 patients with brain tumors, between August 1999 and February 2004. 1HMRS was performed with a TE of 144 ms followed by a TE of 30 ms and/or a TE of 288 ms, if necessary. For the 213 patients, lactate level was "negative" in 47 patients, "positive" in 131 patients, and "strongly positive" in 35 patients. The lipid level was "negative" in 90 patients, "positive" in 56 patients, and "strongly positive" in 67 patients. Based on logistic discriminant analyses of neuro-epithelial tumor WHO grade and lactate and lipid levels, lactate and lipid levels were significant between WHO grades 2 and 3 (P=0.0239) and between grades 3 and 4 (P=0.0347). Lipids are a more significant factor for the discrimination between WHO grades 2 and 3 (P=0.0073) and between grades 3 and 4 (P=0.0048). With our method of varying the TE, it is possible accurately and efficiently to detect lactate and lipids in the brain. We found a significant correlation between lactate and lipid expression and WHO grade of neuro-epithelial tumors.

Aged↗

PubMed2005

Apparent diffusion coefficient of human brain tumors at MR imaging.

PURPOSE: To determine if apparent diffusion coefficient (ADC) can be used to differentiate brain tumors at magnetic resonance (MR) imaging. MATERIALS AND METHODS: Institutional review board approval or informed patient consent was not required. MR images were reviewed retrospectively in 275 patients with brain tumors: 147 males and 128 females 1-81 years old, treated between September 1997 and July 2003. Regions of interest were placed manually in tumor regions on MR images, and ADC was calculated with a five-point regression method at b values of 0, 250, 500, 750, and 1000 sec/mm2. ADC values were average values in tumor. All brain tumor subgroups were analyzed. Logistic discriminant analysis was performed by using ADC, age, and patient sex as independent variables to discriminate among tumor groups. RESULTS: A significant negative correlation existed between ADC and astrocytic tumors of World Health Organization grades 2-4 (grade 2 vs grades 3 and 4, accuracy of 91.3% [P < .01]; grade 3 vs 4, accuracy of 82.4% [P < .01]). ADC of dysembryoplastic neuroepithelial tumors (DNTs) was higher than that of astrocytic grade 2 tumors (accuracy, 100%) and other glioneuronal tumors. ADC of malignant lymphomas was lower than that of glioblastomas and metastatic tumors (accuracy, 83.6%; P < .01). ADC of primitive neuroectodermal tumors (PNETs) was lower than that of ependymomas (accuracy, 100%). ADC of meningiomas was lower than that of schwannomas (accuracy, 92.4%; P < .01). ADC of craniopharyngiomas was higher than that of pituitary adenomas (accuracy, 85.2%; P < .05). ADC of epidermoid tumors was lower than that of chordomas (accuracy, 100%). In meningiomas, ADC was not indicative of malignancy grade or histologic subtype. CONCLUSION: ADC is useful for differentiation of some human brain tumors, particularly DNT, malignant lymphomas versus glioblastomas and metastatic tumors, and ependymomas versus PNETs.

Adolescent↗

PubMed2005

Effect of subthalamic stimulation on mood state in Parkinson's disease: evaluation of previous facts and problems.

In an attempt to clarify the effect of deep brain stimulation (DBS) to the subthalamic nucleus (STN) on mood state, previous evidence and problems were evaluated through a systematic literature search. Twenty three articles reported the effect of STN DBS on mood state in Parkinson's disease (PD), and antidepressant, depressant, and mania-induced effects were reported in 16.7-76%, 2-33.3%, and 4.2-8.1% of the patients treated with STN DBS, respectively. Most articles reported larger subgroups showing antidepressant effects than those showing depressant effects. The average depression scale score of all subjects was improved or unchanged after STN DBS. Although there was a limitation due to the varied results, it was suggested that, in general, STN DBS had an antidepressant effect in PD. However, the studies reporting severe depressant symptoms, such as suicidal attempts, after STN DBS indicated the importance of careful attention to mood state as well as to motor symptoms after STN DBS. It may be crucial to reduce the variation in the results by, for example, the use of standardized protocols and the precise verification of the stimulated region in further investigations to address this issue.

Affect↗

PubMed2005

Churg-Strauss syndrome presenting with subarachnoid hemorrhage from ruptured dissecting aneurysm of the intracranial vertebral artery.

Churg-Strauss syndrome (CSS) represents a rare systemic vasculitis that is almost invariably accompanied by bronchial asthma and eosinophilia. We report a case of a 36-year-old woman with previously diagnosed CSS presented with subarachnoid hemorrhage (SAH) from dissecting aneurysm in a vertebral artery (VA). Two months before onset of SAH, the patient had presented with numbness on her right lower leg due to peripheral neuropathy. On admission, angiography revealed dissecting aneurysm of the right intracranial VA and stenosis of the basilar artery. Hematological examination revealed an increased percentage of eosinophils. Ruptured dissecting aneurysm of the intracranial VA was diagnosed. Emergent coil embolization of the dissecting aneurysm and occlusion of the parent artery was performed to prevent repeated hemorrhage from the dissecting aneurysm. Then pharmacotherapy with prednisone was initiated for CSS. The patient recovered well and was discharged without any neurological deficit. As far as we know, this is the first reported case of CSS presented with SAH from dissecting aneurysm on posterior circulation.

Adult↗

PubMed2005

Malnutrition and nonthyroidal illness syndrome after stroke.

In the present study, nonthyroidal illness syndrome (NTIS), which is characterized by reduction of serum triiodothyronine (T3) without elevation of thyroid-stimulating hormone (TSH), was induced by protein-energy malnutrition (PCM). Protein-energy malnutrition is a common condition and is associated with worse clinical outcome in stroke patients admitted to a rehabilitation service. However, little is known about NTIS in stroke patients. Therefore, we studied the effects of PCM and NTIS on functional dependence in 51 stroke patients. We examined thyroid function by measuring serum free T3 (free T3), free thyroxine (free T4), and TSH. We estimated whether patients had mild NTIS (reduction of only free T3) or serious NTIS (reduction of both free T3 and free T4), examined PCM by measuring serum albumin, calculated body mass index (BMI) from weight and height on admission, and examined disability by obtaining the functional independence measurement (FIM). The 51 patients were divided into 2 groups according to FIM score on admission (low and high). The low-FIM group was divided into 2 subgroups according to the change in FIM score during hospitalization (improved or non-improved). Hypoalbuminemia was observed in 57% of patients, underweight in 22%, and mild NTIS in 82%; serious NTIS was not observed in any patients. Albumin and BMI were significantly higher in the high-FIM group than in the low-FIM group. Serum albumin concentration and BMI significantly positively correlated with free T3. Free T3 (but not albumin or BMI) was significantly higher in the improved subgroup than in the non-improved subgroup. Nonthyroidal illness syndrome after stroke was common and was provoked by PCM, which occurred in a high proportion of functionally dependent patients. It appears that, once stroke patients develop NTIS, it is difficult to achieve functional improvement. Therefore, during the recovery period after stroke, it is important to determine whether NTIS is present and ensure proper intensive rehabilitation and nutritional management.

Adult↗

PubMed2005

Staged bilateral vertebral artery occlusion for ruptured dissecting aneurysms of the basilar artery: a report of 2 cases.

BACKGROUND: Dissecting aneurysm of the basillary artery BA is rare. Although mortality rate is high, management remains controversial. We report 2 cases of dissecting aneurysm of the BA presenting with subarachnoid hemorrhage (SAH), both of which were successfully treated using staged occlusion of bilateral vertebral arteries (VAs). CASE DESCRIPTION: A 64-year-old man and a 34-year-old woman presented with SAH associated with ruptured dissecting aneurysm of the BA. After endovascular occlusion of a single VA, blood flow in the dissected lumen was reduced. However, one aneurysm rebled and the bleb of the other did not change. Vertebral arteries were also occluded using endovascular techniques at 4 and 2 weeks after initial treatment, respectively. On the second intervention, stump pressure ratios of VAs intended for occlusion were 62.5% and 50.6%, respectively. The patients tolerated temporary occlusion of bilateral VAs well. Subsequent permanent occlusion of bilateral VAs resulted in no neurological complication. Complete obliteration of the aneurysmal lumen was demonstrated on magnetic resonance angiography performed 72 and 5 months later, respectively. CONCLUSION: Staged bilateral VA occlusion might be the last recourse to prevent further hemorrhage from BA dissecting aneurysm. The technique can be safely applied when the stump pressure ratio is 50.6% or greater and when the patient tolerates temporary occlusion, which suggests the existence of sufficient collateral flow from the anterior circulation.

Adult↗

PubMed2005

Cortical resection with electrocorticography for intractable porencephaly-related partial epilepsy.

PURPOSE: We evaluated the results of cortical resection of epileptogenic tissue for treatment of intractable porencephaly-related epilepsy. METHODS: We examined clinical features, electrophysiological data, surgical findings, and seizure outcomes after cortical resection in eight patients with intractable epilepsy related to porencephalic cysts. RESULTS: All eight patients had hemiparesis. Five retained motor function in the hemiparetic extremities; six retained visual fields. All had partial seizures, six with secondary generalization. Seven patients had simple and three had complex partial seizures (CPSs); two also had drop attacks. Four patients had multiple seizure types. Long-term scalp video-EEG (LVEEG) localized interictal epileptic abnormalities that anatomically corresponded to the cyst location in three patients. LVEEG recorded ictal-onset zones in five; these anatomically corresponded to the cyst location in three of the five. EEG recorded generalized seizures in two patients, hemispheric in one, and multifocal in two. Intraoperative electrocorticography (ECoG) revealed interictal epileptic areas extending beyond the margins of the cyst in seven patients. We resected ECoG-localized interictal epileptic areas completely in five patients and partially in two. Cortical resection was based on seizure semiology and LVEEG in one patient whose ECoG showed no epileptiform discharges. After a minimum follow-up of 1 year, six patients had excellent seizure outcome (Engel class I), and two had a >90% seizure reduction (Engel class III) without complications. CONCLUSIONS: Cortical resection guided by ECoG allows preservation of motor function and visual field and provides an effective surgical procedure for treatment of intractable epilepsy secondary to porencephaly.

Adolescent↗

PubMed2005

Slow postoperative decline in blood concentration of insulin-like growth factor-1 (IGF-1) in acromegalic patients.

Recent criteria for cure of acromegaly require normalization of the insulin-like growth factor (IGF-1) level. A retrospective study was conducted to assess postoperative sequential changes in the blood IGF-1 level and to determine the appropriate timing for endocrinologic assessment of the effect of surgery. Blood IGF-1 levels were measured at least 3 times (4.9 +/- 2.0, mean +/- SD) during the first postoperative year in 36 acromegalic patients whose glucose tolerance test results, obtained 3 months after surgery, showed the growth hormone level to be suppressed to under 1 ng/mL. Postoperative IGF-1 parameters, i.e. the actual IGF level and %IGF-1 compared to the nadir during the first postoperative year, rapidly decreased during the first 2 postoperative weeks and then slowly declined over the next 2 weeks. They reached a plateau (stable nadir) during the 2nd postoperative month. Assessment of the postoperative endocrinologic status should be delayed at least one month after surgery in acromegalic patients.

Acromegaly↗

PubMed2005

Hypothalamic hamartoma.

The incidence of hypothalamic hamartomas (HHs) has increased since the introduction of magnetic resonance (MR) imaging. The etiology of this anomaly and the pathogenesis of its peculiar symptoms remain unclear, but recent electrophysiological, neuroimaging, and clinical studies have yielded important data. Categorizing HHs by the degree of hypothalamic involvement has contributed to the accurate prediction of their prognosis and to improved treatment strategies. Rather than undergoing corticectomy, HH patients with medically intractable seizures are now treated with surgery that targets the HH per se, e.g. HH removal, disconnection from the hypothalamus, stereotactic irradiation, and radiofrequency lesioning. Although surgical intervention carries risks, total eradication or disconnection of the lesion leads to cessation or reduction of seizures and improves the cognitive and behavioral status of these patients. Precocious puberty in HH patients is safely controlled by long-acting gonadotropin-releasing hormone agonists. The accumulation of knowledge regarding the pathogenesis of symptoms and the development of safe, effective treatment modalities may lead to earlier intervention in young HH patients and prevent the decline in their cognitive abilities and quality of life. This review of hypothalamic hamartomas presents current classifications, pathophysiologies, and treatment modalities.

Hamartoma↗

PubMed2005

Simultaneous cranial and spinal subdural hematoma.

A 59-year-old male presented with spinal subdural hematoma (SDH) with concomitant cranial chronic SDH manifesting as mild paraparesis and numbness in both lower extremities. Magnetic resonance (MR) imaging showed simultaneous occurrence of cranial and spinal SDHs. The patient was treated conservatively because of poor medical condition and mild neurological symptoms, and recovered well within 1 month. Serial follow-up MR imaging revealed spontaneous resolution of both lesions, with signal intensity changes suggesting the degenerative process of subacute hematoma. The spinal hematoma may have migrated from the cranial lesion. Spinal SDH is a potential sequela of chronic SDH in the cranium.

Hematoma, Subdural, Intracranial↗

PubMed2005

Volume subtraction three-dimensional CT angiography for cerebrovascular disease: report of two cases.

We report two cases in which volume subtraction three-dimensional CT angiography (VS-3DCTA) was used for cerebral aneurysm and vascular stenosis with intramural calcification. Case 1: VS-3DCTA with volume rendering clearly showed carotid cave aneurysm of the internal carotid artery. The location and size of the aneurysm was confirmed by digital subtraction angiography (DSA). In evaluation of the aneurysm, VS-3DCTA was equal to DSA and endovascular findings. Case 2: VS-3DCTA with volume rendering clearly showed stenosis of the middle cerebral artery, and intramural calcification with the cause of the stenosis was subtracted. On the other hand, it was difficult for DSA to reveal the stenosis because of the limitation of the imaging angle. In evaluation of the stenosis, VS-3DCTA was superior to DSA. VS-3DCTA was an important diagnostic tool that enabled visualization of the aneurysm in the area of the skull base and stenosis of the intracerebral artery.

Aged↗