Posterior circulation and high prevalence of ischemic stroke among young pediatric patients with Moyamoya disease: evidence of angiography-based differences by age at diagnosis.

BACKGROUND AND PURPOSE: At diagnosis, the primary clinical manifestations of pediatric Moyamoya disease are TIA or CSs. CSs are reported to be more prevalent in younger than in older children. We sought to determine whether age-related differences in clinical manifestations are associated with age-related angiographic differences. MATERIALS AND METHODS: We divided 78 patients diagnosed with Moyamoya disease before 16 years of age into four 4-year age groups and examined the relationships between age at diagnosis and clinical manifestations and angiographic and MR imaging findings. RESULTS: Among the 4 diagnostic age groups, in those younger than 4 years of age, the prevalence of CSs and of infarctions on MR images was highest, and along with severity of steno-occlusive lesions of the PCA, the prevalence was significantly higher than that in the next diagnostic age group (4-7 years), though the severity of steno-occlusive lesions in the ICA and the degree of transdural collaterals did not differ significantly. The prevalence of CSs and infarctions did not differ significantly in the 3 oldest diagnostic age groups, whereas ICA and PCA lesions and transdural collaterals correlated positively with diagnostic age. CONCLUSIONS: The high prevalence of CSs and infarctions in patients diagnosed before 4 years of age is associated with advanced steno-occlusive lesions of the PCA. In patients 4 years of age and older at diagnosis, transdural collaterals develop in parallel with advancement of ICA and PCA lesions, which may contribute to the nearly constant prevalence of CSs.

Use of intraoperative dynamic infrared imaging with detection wavelength of 7-14 microm in the surgical obliteration of spinal arteriovenous fistula: case report and technical considerations.

BACKGROUND AND OBJECTIVE: Although improvements of spatial and temporal resolution in infrared (IR) imaging have enabled intraoperative real-time acquisition of physiological and pathological information on living organs, the imaging qualities of anatomical delineation of blood vessels and functional delineation of blood flow were insufficient to serve as visual monitoring. The main reason was partly due to the lack of an appropriate IR detection IR band (formerly 3 - 5 micro m), and the broad dynamic range in previous modalities. METHODS: To make a good contrast between blood vessels and surrounding tissues, the detection wavelength was shifted to the long-wave (7 - 14 micro m) part of IR spectrum, which includes the peak IR wave from living tissue (9 - 10 micro m), and the dynamic range was confined to +/- 10 degrees C around 35 degrees C. The novel camera system (IRIS IV infrared imaging system) was used for the visual monitoring of blood flow during the obliteration of a spinal perimedullary arteriovenous fistula at Th 7 in 71-year-old male patient. The temperature resolution of camera was 0.15 degrees C, with its intensity resolution of 16 bit (320 x 240 pixels), and data were stored at a rate of 30 frames/second. High-quality delineation of blood vessels and blood flow was obtained all through the procedure without use of cold saline, which was an inevitable procedure to make contrast in the previously used thermography. However, the occasional use of an air blower was helpful to achieve adequate images in the deep and narrow area of the surgical field. The amount of shunt flow reduction was visualized by the intensity in the acquired imaging, which was also confirmed later by digital subtraction angiography. CONCLUSION: From the present experience, it is considered that this type of imaging may be able to substitute intraoperative blood vessel and blood flow monitoring in spinal and other neurosurgical disorders.

Routine clinical adoption of magnetic resonance imaging was associated with better outcome after surgery in elderly patients with a malignant astrocytic tumour: a retrospective review.

BACKGROUND: There is controversy about extensive surgical treatment for a malignant astrocytic tumour in more elderly patients who may have poorer outcomes and higher complication rates. This retrospective study investigated outcome in elderly patients with malignant astrocytic tumour before and after the adoption of routine clinical use of magnetic resonance (MR) imaging. METHODS: During 1982 through 1999, 88 patients with malignant astrocytic tumour aged 60 years or over were treated in our institute. Thirty-seven patients had an anaplastic astrocytoma and 51 had a glioblastoma. Thirty-seven patients treated from 1982 to 1988 did not have pre-operative evaluation by MR imaging (Group A), 26 patients treated from 1989 to 1995 had preoperative MR imaging evaluation (Group B), and 25 patients treated after 1996 underwent preoperative MR imaging with functional brain mapping and intra-operative navigation system monitoring (Group C). FINDINGS: The median survival time was 8.8 months in Group A, 12.7 months in Group B, and 17.6 months in Group C. Patients with glioblastoma in Group B (11.7 months, n = 15) and Group C (16.0 months, n = 19) had significantly longer median survival time than in Group A (6 months, n = 17) (P = 0.0054 between Groups A and B, P = 0.0024 between Groups A and C). Better preoperative performance status, more thorough surgical resection, and better performance status after the initial treatment was obtained after the introduction of MR imaging, and patients with the optimal indicators showed significantly longer survival time compared with the patients without these factors. INTERPRETATION: Pre-operative MR imaging may contribute to longer survival time by providing an earlier diagnosis in patients with better performance status, by allowing more thorough surgical resection, and resulting in better performance status after the treatment.

Stereotactic radiosurgery for nodular dissemination of anaplastic ependymoma.

Dissemination of primary intracranial ependymoma occurs in 10% of all cases and is difficult to treat, so this may be one of the major reasons for the poor prognosis. Two patients with nodular dissemination of anaplastic ependymoma were treated with repeated stereotactic radiosurgery using the gamma knife (GK), resulting in tumour control over 21 months. GK radiosurgery is a safe and effective treatment option for providing good local control in patients with nodular dissemination of ependymoma.

Usefulness of constructive interference in steady state (CISS) imaging for the diagnosis and treatment of a large extradural spinal arachnoid cyst.

We present a rare case of a symptomatic large extradural arachnoid cyst extending from the lower thoracic to sacral region in a 12-year-old boy, who presented with the signs and symptoms of spinal cord compression over 4 years. Since the pedicle of the cyst could not be delineated using conventional magnetic resonance imaging (MRI), cine-mode MRI, and computed tomography scan, partial resection of the cyst was initially performed, which significantly improved motor function. After the first operation, a single pedicle was clearly demonstrated by 3D constructive interference in steady state (CISS) MRI. Thus, additional surgery aimed at closing the dural defect was performed to prevent future enlargement of the cyst. The operative findings were consistent with those of 3D CISS imaging. Clinical and radiological features of this lesion are discussed, focusing on the usefulness of 3D CISS MRI for preoperative evaluation, and especially for delineating the pedicle in cases of large extradural spinal arachnoid cysts.

Intraoperative thermal artery imaging of an EC-IC bypass in beagles with infrared camera with detectable wave-length band of 7-14 microm: possibilities as novel blood flow monitoring system.

OBJECTIVE: In the past, the usefulness of thermal arterial imaging during coronary bypass surgery using an infrared camera has been reported by several investigators. The goal of this study is to apply this novel imaging system for intraoperative arterial imaging, as well as to develop new utilizations for a neurosurgical procedure. MATERIALS: We have attempted real-time imaging of anastomotic and flow status in an external carotid-internal carotid artery (EC-IC) bypass surgery using a new-generation infrared camera (IRIS IV thermographic imaging system) in beagles. No contrast medium or radiation was used to obtain the images. The detectable wave-length band of the infrared lens was 7-14 microm. After completion of bypass monitoring, an additional teflon tube was inserted into a branch of the STA to inject physiological saline of different temperatures to see the changes in cortical images. RESULTS: Anastomotic and flow status were clearly visualized throughout the operation without local surface cooling, which had been an inevitable procedure in coronary imaging to make a pronounced temperature difference between artery and adjacent tissue. In addition, cortical flow territory was visualized after injection of either cold or warm physiologic saline into the artery from an additionally inserted teflon tube into a branch of STA via bypass artery. CONCLUSION: From the present experience, it is considered that infrared imaging using a detectable wave length band of 7-14 microm may be applicable to a wide variety of near surface lesions, providing a non-invasive functional angiography.

Pulsed liquid jet dissector using holmium:YAG laser--a novel neurosurgical device for brain incision without impairing vessels.

BACKGROUND: Neurosurgery has long required a method for dissecting brain tissue without damaging principal vessels and adjacent tissue, so as to prevent neurological complications after operation. In this study we constructed a prototype of such a device and used it in an attempt to resect beagle brain cortex. METHOD: The prototype device consisted of an optical fibre, a Y adaptor, and a nozzle whose internal exit diameter was 100 microm. Cold physiological saline (4 degrees C) was supplied to it at a rate of 40 ml/h. Pulsed liquid jets were ejected from the nozzle by a pulsed Holmium:YAG) (Ho:YAG) laser at an irradiation energy of 300 mJ/pulse. The profile of the liquid jet was observed with a high-speed camera while changing the distance between the optical fibre end and nozzle exit (equivalent to the standoff distance). With this device (3 Hz operation), brain dissection of anaesthetized beagles was attempted while measuring the local temperature of the target. A histological study of the incised parts was also performed. FINDINGS: When the standoff distance was 24 mm, the liquid jet was emitted straight from the nozzle at a maximum initial velocity of 50 m/s. The brain parenchyma was cut with this device while preserving vessels larger than 200 microm in diameter and keeping the operative field clear. The local temperature rose to no more than 41 degrees C, below the functional heat damage threshold of brain tissue. Histological findings showed no signs of thermal tissue damage around the dissected margin. INTERPRETATION: The Ho:YAG laser-induced liquid jet dissector can be applied to neurosurgery after incorporating some minor improvements.

Intraoperative direct neuroendoscopic observation of the aqueduct in Dandy-Walker malformation.

A 3-month-old female infant with Dandy-Walker malformation manifesting as hydrocephalus was treated successfully by only ventriculoperitoneal shunting. A flexible neuroendoscope was used intraoperatively to confirm the patency of the aqueduct, i.e. communication of the ventricular system and the cyst in the posterior fossa. Direct confirmation of the patency of the aqueduct and cyst communication is valuable to select the shunt procedure in the treatment of Dandy-Walker malformation.

Neurohypophyseal germinoma histologically misidentified as granulomatous hypophysitis.

We report a case of neurohypophyseal germinoma appearing as predominantly granulomatous reaction in the first histological examination. A 12-year-old boy presented with diabetes insipidus, panhypopituitarism, and bitemporal hemianopsia. Transsphenoidal exploration for the intrasellar mass lesion extending to the suprasellar region was performed in May 1999. Histological examination revealed granulomatous hypophysitis and corticosteroid therapy was initiated. Six months later, the lesion relapsed despite corticosteroid therapy. Subtotal removal of the lesion was performed via an anterior interhemispheric approach in December 1999. Histological examination revealed typical germinoma. Subsequently, the patient underwent irradiation of 20 Gy to the tumour site and 24 Gy to the whole brain. Magnetic resonance imaging confirmed tumour remission. We must consider the possibility of neurohypophyseal germinoma in patients with granulomatous hypophysitis which does not respond to corticosteroid therapy, and perform re-exploration for more specimens to achieve the correct diagnosis.

Clinical outcome following ultra-early operation for patients with intracerebral hematoma from aneurysm rupture--focussing on the massive intra-sylvian type of subarachnoid hemorrhage.

Of 250 patients admitted with aneurysmal subarachnoid hemorrhage (SAH) from 1994 to 2000, 16 had massive intra-sylvian hematomas. To predict the useful determinants of the clinical outcome for such patients we analyzed our last 16 cases. The study was performed in 2 parts. Part 1 covered the period from 1994 to 1996 and included 5 patients who underwent early surgery. Immediately before operation, Hunt & Kosnik grade (H&K) III was observed in 1, IV in 3 and V in 1 patient. Part 2, from 1997 to 2000, included 11 patients who underwent ultra-early surgery (within 3 hours after admission) with ventriculostomy and with 2 weeks' postoperative management in the ICU. Preoperatively, there were 2 patients with H&K III, 7 with IV, and 2 with V. The results in part 1 showed that 3 out of the 5 patients had poor outcome with symptomatic vasospasm. While in Part 2, seven returned to work, 2 had minimal and 1 had severe neurological deficits with symptomatic vasospasm, and 1 died. We therefore suggest that ultra-early surgery with ventriculostomy and postoperative management in the ICU is the most useful determinant to improve the clinical outcome in the treatment of SAH patients with massive intra-sylvian hematoma.

Recurrent intracranial germinoma outside the initial radiation field with progressive malignant transformation.

A 19-year-old man with a pure germinoma in the pineal region was successfully treated with chemotherapy followed by 24 Gy local irradiation. Eight months later, magnetic resonance (MR) imaging detected ventricular wall dissemination outside the radiation field. Near complete response was achieved again after 28.8 Gy whole brain and 24 Gy whole spine irradiation. Two months later, MR imaging demonstrated recurrence of a mass at the corpus callosum. Gamma knife radiosurgery did not control this mass, so tumour resection was performed. Histological examination revealed immature teratoma. Enlargement of the recurrent mass at the trigone of the left lateral ventricle was found in spite of additional chemotherapy. Tumour extirpation was performed and histological examination revealed embryonal carcinoma. The patient died of tumour progression 34 months after the initial treatment. By a combination of chemotherapy regiments in use today, the initial radiation field to treat intracranial germinomas should not be confined to the tumour bed.

Surgical treatment of a mixed pineocytoma/pineoblastoma in a 72-year-old patient.

BACKGROUND: Although pineal parenchymal tumours are very rare in elderly patients, we recently successfully treated a 72-year-old male patient. Interestingly, the histology of his pineal parenchymal tumour was mixed pineocytoma/pineoblastoma, which is reported to be extremely rare in aged patients. We present his clinical manifestations, follow-up MRI, surgical treatment, pathological findings, and review the literature. CLINICAL MATERIAL: This 72-year-old man had a mass in the pineal region detected 3 years previously on MRI in February 1996 following symptoms of headache and vertigo. Two years later, he experienced gait disturbance and disorientation. CT scans disclosed obstructive hydrocephalus, and ventriculo-peritoneal shunt placement was then performed. The tumour mass began to enlarge in July 1999 (at age 72). On October 13, 1999, total removal of the pineal region tumour was performed through an occipital transtentorial approach. The postoperative course was uneventful. The pathological diagnosis of the tumour was mixed pineocytoma/pineoblastoma. CONCLUSION: Pineal parenchymal tumours are uncommon in elderly patients, and mixed pineocytoma/pineoblastomas are particularly rare. We followed this patient closely for more than 3.5 years and finally performed total surgical removal of the tumour, with excellent outcome. The present case suggests that a mixed pineocytoma/pineoblastoma tumour is controllable even in elderly patients through careful evaluation and management.

Mesial temporal lobe epilepsy with lateral temporal lobe abnormalities in magnetoencephalography and glucose metabolism.

Magnetoencephalography (MEG) and positron emission tomography (PET) revealed abnormal findings in the lateral temporal lobe of a 22 year old female with mesial temporal lobe epilepsy. Electroencephalography identified the epileptogenic focus in the left mesial temporal lobe and standard anterior temporal lobectomy resulted in a good surgical outcome. These discrepancies can be explained by the presence of anatomical and functional pathways between the mesial and lateral temporal structures, or pathophysiological abnormalities in both the mesial and lateral temporal lobes. Careful evaluation is necessary for analysis of MEG and PET findings in patients with temporal lobe epilepsy.

[Primary aldosteronism presented with intracranial hemorrhage].

Although primary aldosteronism (PA) has been reported as a relatively benign form of hypertension and is associated with low incidence of vascular complications, recent reports indicate that PA complicated by cerebral vascular accidents is not rare. The authors reported here that a 57-year-old man was diagnosed as a case of PA 4 years after initial treatment of intracerebral hemorrhage (ICH) and hypertension. The patient was transferred to our department for further management of his left hemiplegia and hypertension after surgical treatment for a putaminal ICH at the age of 53. During the first 2 years of follow-up, he did well except for an episode of transient motor weakness. Diastolic hypertension was moderately good, controlled by calcium antagonists and ACE inhibitors. Laboratory data was normal, and the serum potassium levels were in the lower limits of normal. In the last 2 years, episodes of motor weakness have increased. He was admitted to our hospital, under the suspicion of recurrent Todd's paralysis. The serum potassium level ranged from 1.9 to 2.1 despite administration of potassium agents. Abdominal CT scans and 131 I-scintigraphy disclosed a left adrenal tumor. Elevation of plasma aldosterone and suppression of plasma renin were observed. The diagnosis of PA due to hypersecretion of aldosterone from an adrenal tumor was thus confirmed. We performed a total left adrenectomy 4 weeks after his admission. Histological examination showed a clear-cell type of benign adrenal adenoma. After the operation, laboratory data were normal and ACE inhibitors were able to normalize his diastolic hypertension. According to the literature, PA complicated by ICH is associated with a high rate of recurrence of cerebral vascular accidents if treatment of PA is not performed. Although diagnosis of PA in the early stage is difficult, as it was in our presented case, high suspicion of PA is essential for patients with diastolic hypertension and persistent hypopotassiumemia, particularly in young adults and middle-aged patients.

Aspergillus parasellar abscess mimicking radiation-induced neuropathy. Case report.

BACKGROUND: Transsphenoidal surgery is a safe procedure for treatment of pituitary adenomas. However, several complications, including post-surgical infection, are known. We describe a case of Aspergillus parasellar abscess that presented with cranial neuropathies following transsphenoidal surgery and radiosurgery. We initially diagnosed the case as radiation-induced neuropathies, which delayed the detection of Aspergillus. CASE DESCRIPTION: A 55-year-old man underwent transsphenoidal surgery for a pituitary adenoma that presented with pituitary apoplexy. Dexamethasone had been continuously administered for hypocortisolism probably caused by pituitary apoplexy. Four years later, radiosurgery was performed for a relapse in the right cavernous sinus. Another 4 years later, he developed painful right ophthalmoplegia, right ptosis, and bilateral visual impairment, successively. We initially suspected that the painful ophthalmoplegia and ptosis were because of radiation-induced cranial neuropathies; however, results of magnetic resonance (MR) imaging and his clinical course were not consistent with those of radiation-induced neuropathies. Therefore, we performed exploratory surgery that revealed a subdural abscess on the planum sphenoidale. Culture of a specimen grew Aspergillus fumigatus. CONCLUSION: Intracranial fungal abscess is a fatal complication unless it is treated early. It is thus important to consider the possibility of parasellar infection and differentiate it from radiation-induced cranial neuropathies when a patient presents with cranial neuropathies after transsphenoidal surgery and radiosurgery.

Hepatitis C virus (HCV) infection as a risk factor for spontaneous intracerebral hemorrhage: hospital based case-control study.

Hepatitis C Virus (HCV) infection was investigated as a risk factor for intracerebral hemorrhage (ICH) by HCV antibody screening in 462 patients with ICH and 462 control patients with cerebral infarction matched by age and sex. Laboratory examinations of hemostatic parameters and cholesterol level were also performed in patients with ICH. HCV infection was significantly more frequent in patients with ICH than controls (8.7% vs 3.5%, P< 0.01). ICH patients with HCV infection had significantly higher L-alanine:2-oxoglutarate aminotransferase level (P< 0.001), lower cholesterol level (P< 0.05), lower platelet count (P< 0.05), and longer prothrombin time (P< 0.01) than ICH patients without HCV infection, although most of these values were within the normal range. These results demonstrate that HCV infection is a risk factor for spontaneous ICH. Subclinical clotting disorder and/or vessel wall friability resulting from hypocholesteremia may be associated with ICH in patients with HCV infection.

Intraaneurysmal embolization of an unruptured basilar tip aneurysm associated with moyamoya disease.

We describe a patient with moyamoya disease associated with an unruptured basilar tip aneurysm which was treated by endovascular embolization using Guglielmi detachable coils (GDCs). A 53-year-old man presented with left hemiparesis persisting for 3 mon ths before admission. Cerebral angiography revealed occlusion of the bilateral middle cerebral arteries and the left anterior cerebral artery, stenosis of the right anterior cerebral artery, and basal moyamoya vessels. In addition, a saccular small aneurysm was seen at the top of the basilar artery. The aneurysm was completely embolized by intraaneurysmal GDCs. Direct surgical clipping is often selected for the treatment of posterior fossa aneurysms in moyamoya disease. However, complete clipping is usually difficult due to the difficulties in operative technique associated with moyamoya disease. We suggest that the endovascular treatment using GDCs is comparatively safe and effective for the treatment of surgically difficult aneurysms in patients with moyamoya disease.

Surgical treatment of posterior fossa tumors via the occipital transtentorial approach: evaluation of operative safety and results in 14 patients with anterosuperior cerebellar tumors.

OBJECT: To determine the safety and usefulness of performing surgery via the occipital transtentorial approach to treat anterosuperior cerebellar tumors, evaluation of 14 patients was performed over a 5-year period. METHODS: The study was performed in 14 patients, aged 6 months to 71 years, who harbored anterosuperior cerebellar tumors of the posterior fossa including four hemangioblastomas, three cerebellar astrocytomas, three medulloblastomas, two metastatic tumors, one recurrent astrocytoma, and one rhabdoid cell tumor. All patients underwent surgical treatment by the same surgical team and via the same surgical approach. Endoscopy combined with neuronavigation was used for large, deep-seated tumors extending to the fourth ventricle. Of the 14 patients, total or gross-total removal was achieved in 12 patients and subtotal removal in two patients. There was no incidence of mortality or morbidity in the 14 patients, and all functional outcomes were good to excellent postoperatively. Postoperative magnetic resonance imaging revealed that none of the patients had suffered brain damage or infarction around the cerebellum, brainstem, or occipital lobe. CONCLUSIONS: Although this study was the first in which a specific examination of the efficacy of the occipital transtentorial approach in patients with anterosuperior cerebellar tumors was undertaken, our findings suggest that this surgical approach is very useful, safe, and accurate for removing the primary tumor and evaluating the surrounding anatomy, as well as for determining operative strategy.