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Tomoya Ishiguro

Publications and source records attributed to Tomoya Ishiguro.

15 recordsLinked to original sources
PubMed2005

A brainstem cavernoma demonstrating a dramatic, spontaneous decrease in size during follow-up: case report and review of the literature.

BACKGROUND: Many reports have demonstrated a worse prognosis for patients whose cavernomas were subtotally removed than for those whose cavernomas were not surgically treated. Therefore, it is better not to touch the cavernoma if a surgeon is not prepared to totally remove it. This report describes a large brainstem cavernoma showing a spontaneous, dramatic reduction in size after removal of only the biopsy specimen of the lesion. CASE DESCRIPTION: A 42-year-old woman experienced facial numbness, diplopia, and ataxia. A magnetic resonance (MR) study revealed a pontine cavernoma with hemorrhage. Two weeks later, recurrence of the patient's symptoms and consciousness disturbance were noted. An MR study revealed massive hemorrhage from the cavernoma with a ventricle dilatation. An operation on the lesion was conducted 3 months after the initial hemorrhage. However, the operation was aborted when an exploration of the lesion showed a tight adhesion between the lesion and the pons. Removal of only a biopsy specimen and evacuation of the suckable hematoma were done. No neurologic recovery and no decrease in the size of the cavernoma were detected postoperatively. Her family did not wish for further treatments. She was in a bedridden state with severe brainstem dysfunction when she was transferred to a local hospital. Sixteen months after the surgery, her consciousness was clear, and MR imaging confirmed a marked reduction in the size of the cavernoma. CONCLUSION: A dramatic, spontaneous decrease in size does occur even in the case of a large brainstem cavernoma showing hemorrhages. Conservative therapy may be one of the treatment options for the symptomatic brainstem cavernoma.

Adult↗
PubMed2004

Regrowth and fatal rerupture despite proximal occlusion after coil embolization of a ruptured large basilar bifurcation aneurysm--case report.

A 40-year-old man suffered chronic progressive symptoms of brainstem compression after undergoing endosaccular coil placement in a ruptured large basilar bifurcation aneurysm. Radiographical examinations showed coil compaction and regrowth of the aneurysmal mass with perifocal mesencephalic edema. The symptoms did not resolve even after additional clip occlusion of the upper basilar artery and the patient died of rerupture. At present, direct surgical clipping using a skull base technique with or without hypothermic circulatory arrest or upper basilar artery occlusion with or without bypass surgery may be a better choice as an initial treatment for giant or large basilar bifurcation aneurysm with a wide neck.

Adult↗
PubMed2004

Endovascular treatment of dural sinus malformation with arteriovenous shunt in a low birth weight neonate--case report.

A boy was born at 36 weeks gestation weighing 2,135 g, with a prenatal diagnosis of dural sinus malformation with arteriovenous shunts. Congestive heart failure and anuria at birth prompted emergency intervention. Transfemoral-transvenous coil embolization was performed on day 1, resulting in partial occlusion of the huge venous pouch with a total length of 2,355 cm of detachable coils. Transarterial glue embolization on days 7, 23, and 42 was required due to persistent heart failure. Transarterial embolization was performed by common carotid puncture because the transfemoral route could not be used due to the small size and compromised blood flow of the femoral artery. Transarterial embolization reduced the arteriovenous shunts markedly and resulted in clinical improvement. Early treatment of a high flow dural arteriovenous fistula in a low birth weight neonate can achieve an excellent result with an acceptable neurological outcome.

Arteriovenous Shunt, Surgical↗
PubMed2004

Serial antenatal sonographic observation of cerebral dural sinus malformation.

Dural sinus malformation is an extremely rare congenital cerebrovascular malformation. We report serial antenatal sonographic findings in two patients with dural sinus malformation. Sonography can reveal dural sinus malformation at 24 weeks' gestation. Correct and early diagnosis may help determine the appropriate place, timing, and mode of delivery, which may result in a better therapeutic course and patient outcome.

Adult↗
PubMed2004

[Neuroanatomical study of the internal structures of the brain based on brain fiber dissection].

From the beginning of the 17th Century, anatomists started to elucidate numerous tracts and fasciculi of the brain using fiber dissection techniques. Due to the complexities associated with tissue preparation and the time-consuming nature of traditional techniques the popularity of this method has gradually declined with the advent of modern neuroimaging techniques such as MRI. Many novel approaches to deep brain lesions have recently been devised following the development of skull base surgery. In comparison, the study of functional neuroanatomy has been relatively neglected. Understanding how neuronal fibers in the brain interconnect and communicate neuronal functions is critical when performing surgery for malignant glioma and epilepsy, as brain parenchyma has to be resected and neuronal fibers are interrupted. In the preoperative planning process we have applied anatomical studies using brain fiber dissection techniques. Brain fiber dissection offers the advantage of exposing association, commissural and projection fibers of cerebral white matter in three dimensions. Brain fiber dissection appears useful for assisting neurosurgeons to acquire neurosurgical skills and become familiar with neuroanatomical features. The techniques and significance of brain fiber dissection are described herein.

Brain↗
PubMed2003

Surgery combined with radiosurgery of large acoustic neuromas.

UNLABELLED: The treatment of acoustic neuromas has been improved by advancements in microsurgical techniques and in radiosurgery. To further elucidate the degree of clinical improvement, we evaluated the treatment results of a combination of surgery and radiosurgery for large acoustic neuromas. METHODS: From January 1994 through December 2000, we treated 14 patients with large acoustic neuromas using a combination of surgery and radiosurgery. Of these, 8 were male and 6 were female patients, with an average age of 47 years (range, 18-64). The average maximum diameter of the tumor was 42 mm (range, 30-58 mm). All patients underwent operations using the retrosigmoid approach, and one patient was retreated using the transpetrosal transtentorial approach. The tumors were removed subtotally in thirteen patients and partially in one who had a very large hypervascular acoustic neuroma. There were no mortality and no surgical complications, such as hemorrhage or CSF leakage. Postoperative facial palsy was avoided in 10 patients (71%). Radiosurgery was performed 1 to 6 months (mean, 2.9 months) after surgery. At the time of radiosurgery, the treatment size (mean diameter) became 19.2 mm (range, 9.8-36.1 mm). The average tumor marginal dose was 12.1Gy (range, from 10-14 Gy). The mean follow-up period was 32 months after radiosurgery. RESULTS: The tumor size decreased in 6 patients, unchanged in 5 patients, and increased in 3 patients. Only 1 patient (7%) with extra large tumor needed surgical resection 1 year after radiosurgery. Excellent facial nerve function (House & Brackmann Grade I or II) was preserved in 12 patients (85.7%) in the final follow-up. CONCLUSIONS: In the case of large acoustic neuromas, subtotal removal and subsequent radiosurgery is one option for maintaining cranial nerve function and long-term tumor growth control.

Adolescent↗
PubMed2003

Gamma knife radiosurgery for the treatment of cavernous sinus meningiomas.

OBJECTIVE: We report on the efficacy of gamma knife radiosurgery for cavernous sinus meningiomas. METHODS: Between January 1994 and December 1999, we used gamma knife radiosurgery for the treatment of 43 patients with cavernous sinus meningiomas. Forty-two patients were followed up for a mean of 49.4 months (range, 18-84 mo). The patients' average age was 55 years (range, 18-81 yr). Twenty-two patients (52%) underwent operations before radiosurgery, and 20 patients (48%) underwent radiosurgery after the diagnosis was made by magnetic resonance imaging. The tumor volumes ranged from 1.2 to 101.5 cm(3) (mean, 14.7 cm(3)). The tumors either compressed or were attached to the optic apparatus in 17 patients (40.5%). The marginal radiation dose was 8 to 15 Gy (mean, 11 Gy), and the optic apparatus was irradiated with 2 to 12 Gy (mean, 6.2 Gy). Three patients with a mean tumor diameter greater than 4 cm were treated by two-stage radiosurgery. RESULTS: Thirty-eight patients (90.5%) demonstrated tumor growth control during the follow-up period after radiosurgery. Tumor regression was observed in 25 patients (59.5%), and growth was unchanged in 13 patients (31%). Regrowth or recurrence occurred in four patients (9.5%). The actual tumor growth control rate at 5 years was 92%. Only one patient (2.4%) experienced regrowth within the treatment field; in other patients, regrowth occurred at sites peripheral to or outside the treatment field. Twelve patients (28.6%) had improved clinically by the time of the follow-up examination. None of the patients experienced optic neuropathy caused by radiation injury or any new neurological deficits after radiosurgery. CONCLUSION: Gamma knife radiosurgery may be a useful option for the treatment of cavernous sinus meningiomas not only as an adjuvant to surgery but also as an alternative to surgical removal. We have shown it to be safe and effective even in tumors that adhere to or are in close proximity to the optic apparatus.

Adolescent↗
PubMed2003

[Surgical stress in patients with asymptomatic unruptured intracranial aneurysms].

BACKGROUND: Surgical stress elicits a characteristic response involving induction of synthesis and release of acute-phase proteins such as C-reactive protein (CRP). To objectively evaluate the surgical stress in patients with asymptomatic unruptured intracranial aneurysms, serum levels of CRP after direct clipping via the pterional approach were measured. METHODS: 42 patients who experienced an uneventful postoperative course, were evaluated according to age (less or more than 65 years old [adult or elderly]), aneurysmal location (middle cerebral artery territory [MC], anterior communicating artery [Acom] or internal carotid artery territory [IC]) and intraoperative trauma (positive or negative). We defined intraoperative trauma as intentional vein cutting, perforator vessel injury or suction of the gyrus rectus. All patients received standardized general anesthesia and were treated after the operations according to our standard protocols. Serum levels of CRP on postoperative day 2 were compared in each category. RESULTS: Serum levels of CRP showed no significant difference between the adult group and the elderly group, but were greater in Acom patients than in MC and IC patients (p < 0.01, p < 0.05). As to intraoperative traumas, the positive group (almost all were intentional vein cutting) showed greater CRP levels than the negative group in MC and IC patients (p < 0.05). Operation time and volume of blood loss were almost the same in each category. CONCLUSION: Our study shows that as far as serum levels of CRP are concerned, Acom location and vein cutting are the main factors of surgical stress in cases of unruptured aneurysms.

Aged↗
PubMed2003

[The surgical treatment strategy and results of parasellar meningiomas in the era of radiosurgery].

We evaluated the surgical treatment results of parasellar meningiomas in the era of radiosurgery. We treated 24 patients of parasellar meningiomas surgically. The median age was 60 yrs (ranging from 29 to 82 yrs). The most common tumor location was the sphenoid ridge in 12 patients and the tuberculum sellae in 7 patients. The pterional approach using fronto-temporal craniotomy was performed for all patients. The residual or recurrent tumors were treated by gamma knife radiosurgery (GKS). We are able to follow up these cases for a median of 3.8 yrs (ranging from 1 to 8 yrs) after the operations. The radicality of tumor resection was Simpson grade II in 13 patients (54%), grade III in 3 patients (13%) and grade IV in 7 patients (33%). Clinical improvement was achieved in 81% of the patients. Of the patients who had visual disturbance preoperatively, 8 patients (73%) showed improvement, but 3 patients suffered deterioration postoperatively. None of the patients died. One patient suffered transient memory disturbance and one patient suffered mild facial numbness postoperatively. Boost radiosurgery for the residual tumors was performed for six patients and tumor growth control was able to be achieved in all patients, with a median of 3.1 years follow-up period (ranging from 0.5 to 6 yrs). Five patients with tumor regrowth or recurrence were treated by GKS. We recommend fronto-temporal craniotomy with nonradical resection for parasellar meningiomas and radiosurgery for residual and recurrent tumors. This strategy will achieve good functional outcome with long-term tumor growth control.

Adult↗
PubMed2003

[The treatment for asymptomatic meningiomas in the era of radiosurgery].

We evaluated the treatment results in asymptomatic meningiomas in the era of radiosurgery. We encountered 56 patients with asymptomatic meningiomas from January, 1994 to December, 2001. There were 16 male patients and 40 female patients. The most common location was the cerebral convexity. We performed gamma knife radiosurgery for three patients after diagnosis of cavernous sinus meningiomas. The other patients were followed-up after diagnosis for a mean follow-up period of 30.8 months (5 months to 8 years). Tumor growth was verified in 25 patients (43%) and two patients (3.7%) suffered neurological deficits. Among the tumor growth patients, operative resection was performed in six patients (11%) and gamma knife radiosurgery was performed in four patients (7.5%). The other patients were placed under observation. We decided the treatment strategy paying attention to the tumor location, tumor growth speed, tumor size and operative difficulty. The tumor growth rate was 0.1 cm/year among the patients with tumor growth. It was 0.72 cm/year (0.02 to 1.54 cm/year) in the operative group, 0.3 cm/year (0.04 to 0.76 cm/year) in the gamma knife radiosurgery group and 0.08 cm/year (0.01 to 0.76 cm/year) in the observed group. One patient suffered procedure-related deterioration of paresis after operation. The treatment of asymptomatic meningiomas must be decided depending on their natural history and locations. We recommend early radiosurgery for cavernous sinus meningiomas.

Aged↗
PubMed2002

Constructive interference in steady state imaging of moyamoya disease.

The diagnostic accuracy of three-dimensional constructive interference in steady state (CISS) magnetic resonance (MR) imaging was evaluated for the assessment of idiopathic moyamoya disease. Six consecutive patients underwent MR angiography, CISS imaging, and digital subtraction angiography. MR angiography and CISS imaging visualization of the steno-occlusive changes in the distal internal carotid arteries and the development of moyamoya vessels in the basal cistern were compared to the results obtained by digital subtraction angiography. MR angiography revealed the steno-occlusive changes correctly in nine and overestimated the changes in three of 12 hemispheres examined. CISS imaging showed the steno-occlusive changes defined as decreased caliber of the internal carotid artery correctly in two, underestimated the changes in nine, and overestimated the changes in one of the 12 hemispheres. MR angiography detected moyamoya vessels correctly in five and underestimated the vessels in seven of the 12 hemispheres. CISS imaging revealed the moyamoya vessels correctly in 10, underestimated the vessels in one, and overestimated the vessels in one of the 12 hemispheres. CISS imaging can supplement MR angiography in the non-invasive diagnosis of moyamoya disease, especially for the evaluation of moyamoya vessels.

Adolescent↗
PubMed2002

[Dejerine-Roussy syndrome following endovascular parent artery occlusion for an unruptured posterior cerebral artery aneurysm (P2 segment): case report].

A right posterior cerebral artery (PCA) fusiform aneurysm was incidentally discovered in a 53-year-old man. Although the aneurysm was asymptomatic, treatment of the aneurysm was indicated to avoid possible hemorrhage and/or mass effect. Since the patient tolerated temporary balloon occlusion of the right PCA at P1-P2 segments and sufficient collateral flow to the right temporo-occipital region was observed during such occlusion, parent artery occlusion as well as intraluminal occlusion of the aneurysm was performed with Guglielmi detachable coils. The patient did not develop neurological deficit immediately after embolization. However, he subsequently developed Dejerine-Roussy syndrome due to an infarction in the territory of the thalamogeniculate artery. Parent artery occlusion together with intraluminal aneurysmal obliteration is an useful treatment for a fusiform aneurysm of the PCA. However, ischemic complication in the territory of the perforating artery can not be predicted.

Balloon Occlusion↗
PubMed2002

[Results of treatment for male prolactinomas].

We evaluated the results of medical treatment for male prolactinomas. We encountered eight patients with male prolactinomas. The age was 25 to 54 years old (mean 43 years) and the chief clinical symptoms were visual acuity/field defect in three patients, pituitary apoplexy in one patient, disturbance of ejection in one patient, generalized convulsion in one patient, headache in one patient and general fatigue in one patient. The serum prolactin level was 279 to 7,360 ng/ml (mean 2,832 ng/ml). The tumors in all patients were large with a mean diameter of 34.9 mm (range, 21 to 43 mm). In only one patient, the operation was performed due to pituitary apoplexy. All the patients were treated by medication, with bromocriptine being used in seven patients and terguride in one. The follow-up period was 0.8 to 13 years (mean 5.9 years) and, in all patients, the medical treatment was continued. The tumor decreased in size in all patients and the serum prolactin level at the last follow-up observation was 0.5 to 70.5 ng/ml (mean 26.9 ng/ml). All the neurological symptoms disappeared in the early stage of treatment. As for the complications of medical treatment; in one patient, orthostatic hypotension occurred during the initial administration of bromocriptine and one patient suffered CSF leakage two months after the administration of bromocriptine, so the repair of the sella floor by transsphenoidal surgery was necessary. The medical treatment for male prolactinomas is effective for a long term and should be the primary treatment for the male prolactinomas. In conclusion, patients can maintain a good quality of life for a long time by using dopamine agonists.

Adult↗