Preliminary study on the clinical application of augmented reality neuronavigation.

OBJECTIVE: To develop an augmented reality (AR) neuronavigation system with Web cameras and examine its clinical utility. METHODS: The utility of the system was evaluated in three patients with brain tumors. One patient had a glioblastoma and two patients had convexity meningiomas. Our navigation system comprised the open-source software 3D Slicer (Brigham and Women's Hospital, Boston, Massachusetts, USA), the infrared optical tracking sensor Polaris (Northern Digital Inc., Waterloo, Canada), and Web cameras. We prepared two different types of Web cameras: a handheld type and a headband type. Optical markers were attached to each Web camera. We used this system for skin incision planning before the operation, during craniotomy, and after dural incision. RESULTS: We were able to overlay these images in all cases. In Case 1, accuracy could not be evaluated because the tumor was not on the surface, though it was generally suitable for the outline of the external ear and the skin. In Cases 2 and 3, the augmented reality error was ∼2 to 3 mm. CONCLUSION: AR technology was examined with Web cameras in neurosurgical operations. Our results suggest that this technology is clinically useful in neurosurgical procedures, particularly for brain tumors close to the brain surface.

Postoperative evaluation of changes in extracranial-intracranial bypass graft using superficial temporal artery duplex ultrasonography.

BACKGROUND AND PURPOSE: Extracranial-intracranial (ECIC) bypass grafts have been assessed postoperatively by various neuroradiologic techniques. The aim of this prospective study was to evaluate postoperative changes in ECIC bypass graft by using superficial temporal artery duplex ultrasonography (STDU). Furthermore, this study assessed the ability of STDU to predict cerebrovascular reserve capacity (CVR). MATERIALS AND METHODS: Forty-five consecutive patients who underwent ECIC bypass procedure for atherosclerotic internal carotid artery occlusion were enrolled in this prospective study. All patients underwent single-photon emission CT and STDU preoperatively, 14 days after, 3 months after, 1 year after, and 2 years after ECIC bypass. RESULTS: The diameter and flow velocities of the ipsilateral superficial temporal artery (STA), and regional cerebral blood flow (rCBF) showed increase during the first 2 weeks and then remained stable, whereas CVR showed a constant improvement up to 2 years after surgery. The STA diameter and mean STA flow velocity correlated significantly with CVR at 1 year after surgery (r2 = 0.1232 and r2 = 0.08716, respectively; P < .05). A cutoff value of 1.8 mm STA diameter was determined as the most reliable value to predict CVR greater than 10% at 1 year after surgery. The positive predictive value was calculated as 96.6%, the negative predictive value as 43.8%, the sensitivity as 75.7%, the specificity as 87.5%, and the likelihood ratio as 6.056. CONCLUSIONS: ECIC bypass grafts can be assessed postoperatively in a noninvasive fashion with STDU. This technique provides information regarding patency as well as quantitative assessment of bypass function. Moreover, STDU is useful to predict CVR improvement.

Mobile intracranial oily substances from a ruptured teratoma.

A patient with a ruptured intracranial teratoma is presented. The distinctive imaging and neuroendoscopic findings of mobile fatty or oily globules in the subarachnoid or ventricular space are described. Fat suppression magnetic resonance imaging (MRI) and MRI performed with the patient prone was helpful in distinguishing tumour tissue from floating oil.

Resolving obstructive hydrocephalus from AVM.

Obstructive hydrocephalus with deterioration of consciousness from a ruptured arteriovenous malformation (AVM) requires urgent decompression, but also vigilance during the preoperative stage in case of rare spontaneous resolution.

Evolution of malignant cerebellar astrocytoma at the site of a treated medulloblastoma: report of two cases.

The authors report two unusual cases in which a malignant astrocytoma developed at the site of the excision of an earlier medulloblastoma. While the precise etiology of these astrocytic tumours was unproven, theories of the origins of the second tumours, particularly in relation to the basic nature of medulloblastomas, are discussed.

Efficacy of single-bolus vs. frequent low-dose treatment with nitrosourea in experimental gliomas.

BACKGROUND: Malignant glioma remains a fatal disease. Continuous or frequent low-dose (FLD) chemotherapy with nitrosoureas reportedly causes fewer side-effects than single-bolus therapy without decreasing the antitumour effects. MATERIALS AND METHODS: To study the effect of FLD treatment with nimustine (ACNU) in rats with glioma, we intracerebrally inoculated with C6 glioma cells. We began the ACNU treatment 5 or 8 days later (total dose, 25 or 40 mg/kg) i.p. as either one bolus or smaller doses spread over 5 days week. RESULTS: At a total dose of 25 mg/kg beginning at day 8, survival duration did not differ between untreated controls and the FLD group, while the bolus significantly prolonged survival; the FLD group showed some improvement beyond control survival at 40 mg/kg (each p <0.001). Beginning treatment after 5 rather than 8 days prolonged survival somewhat further. CONCLUSION: FLD treatment with ACNU is less effective against experimental glioma in rats than bolus treatment.

Neuroendoscopic treatment of cystic craniopharyngioma in the third ventricle.

The third ventricle is a relatively uncommon location for craniopharyngiomas. Generally, craniotomy has been considered the procedure of choice in such cases. We describe a girl in whom a cystic third ventricular craniopharyngioma was successfully treated by evacuation of the cyst contents via a flexible neuroendoscope and precise placement of an Ommaya reservoir catheter within the tumor.

[A case showing effective radiotherapy for a radiation-induced glioblastoma].

Radiation-induced glioblastoma is usually resistant to all treatments. We report a case with radiation-induced glioblastoma, in which radiotherapy was remarkably effective. A 14-year-old female with a history of acute lymphoblastic leukemia, at the age of 7, underwent 15 Gy of radiotherapy to the whole brain. She was admitted to our department due to the development of headache and nausea. Magnetic resonance imaging showed an irregularly enhanced mass in the left frontal lobe. Partial removal of the mass was performed and histological examination showed it to be glioblastoma with a high MIB-1 index. The patient underwent 40 Gy of local radiotherapy and chemotherapy with ACNU and Interferon-beta for 2 years. The residual tumor disappeared after the radiotherapy, and her status is still "complete remission", 29 months after the onset.

[Acute hepatitis B virus after chemotherapy for a case with germinoma].

A 28-year old man with HCG-producing germinoma had undergone chemotherapy and radiotherapy. On admission for the fifth session of maintenance chemotherapy, he was found to be positive for hepatitis B (HB)s antigen, but negative for HBs antibody. HBs antigen had been negative during previous admissions. Since liver function was normal, the patient underwent chemotherapy. During myelosuppression after chemotherapy, liver dysfunction developed and acute HB was diagnosed. He fortunately showed seroconversion 2 months after onset. Serum immunological examinations are required for patients receiving chemotherapy.

[Primary thalamic hemorrhage penetrating to the lateral ventricle in an infant with abnormal protein S(protein S-Tokushima)].

We experienced a 3 months infant with thalamic hemorrhage penetrating to lateral ventricle with abnormal Protein S. Although the coagulation factor and fibrinogenolysis factors were evaluated, there were no remarkable abnormal laboratory data except for slightly decline of Protein S. The DNA analysis was performed for Protein S, and a missense mutation(A to G transmission) was found, which was resulting in Lys-155 to Glu. The total Protein S antigen was normal level, but co-factor activity for activated Protein C was declined. That mutation is named Protein S-Tokushima, and the patient who has abnormal Protein S tends to suffer recurrent coagulopathy. In our patient, it was interesting that any thrombotic disease had not occurred, but cerebral hemorrhage had occurred.

[Educational level of patients with germ cell tumor radiated in childhood].

In order to estimate the influence of radiotherapy on the intellectual development of children with brain tumor, we investigated the educational level of 21 patients with germ cell tumor who had undergone radiotherapy. They were divided into three groups in accordance with their age at the time of radiation; under school age group (under 6 years of age), elementary school age group (from 7 to 12 years of age), and junior high and high school age group (from 13 to 18 years of age). There were 2 cases in the under school age group, one of them graduated from high school and the other is presently a junior high school student. There were 5 cases in the elementary school age group. 3 of these graduated from university, 1 is presently a university student and 1 is a high school student. There were 14 cases in the junior high and high school age group. 2 of these are university students, 7 graduated from high school, 1 is presently a junior high school student, and 4 died because of tumor progression. The mean period of hospitalization of the patients who have been admitted to university was 63.0 days, and that of patients who have not been admitted university was 135 days. There is a statistical difference (p < 0.05). It could be concluded that the period of hospitalization rather than radiotherapy seemed to influence the educational status of children with brain tumor.

Fluid loading in rats increases serum brain natriuretic peptide concentration.

Hyponatremia after subarachnoid hemorrhage has been linked to high plasma concentration of atrial natriuretic peptide and brain natriuretic peptide. Volume expansion therapy to prevent symptomatic vasospasm, such as intensive hypertensive and hypervoremic therapy, may alter systemic concentration of these peptides. We therefore examine brain natriuretic peptide secretion in rats in response to acute volume expansion, infusing to 10 ml of saline over 1 h. In the 10 ml group, brain natriuretic peptide concentrations showed a significant increase from pre-infusion concentrations 1 h after initiation of infusion, but had begun to fall 1 h later. We suspect that high plasma concentration of brain natriuretic peptide after subarachnoid hemorrhage is partly caused by hypervoremic therapy.

[A case of symptomatic cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)].

We here report a 42-year-old woman diagnosed cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) by age, family history, neurological findings, and neuro imagings. Magnetic resonance imaging well demonstrated the multiple lesions in the cerebrum including the brain stem, which was characteristic findings in CADASIL.

[A case of effective urgent irradiation therapy for metastatic spine tumor].

A 74-year-old man noticed weakness in bilateral lower limbs 2 months prior to admission. The weakness had rapidly progressed and he could not stand by himself on admission. All thoracic vertebral bodies showed mosaic pattern on T 2 weighted-image. At Th 10 and Th 11, two enhanced masses compressed spinal cord posteriorly. Basal-serum tumor markers, such as LDH, ALP, total-acid phosphatase and prostatic acid phosphatase were elevated, metastatic spine tumor from prostatic carcinoma was suspected. Biopsy specimen from its prostate revealed low differentiated adenocarcinoma. Because sphincter dysfunction progressed rapidly after admission, we started 3 Gy/day irradiation within 24 hr from its appearance targeting both Th 10 to L 1 vertebral bodies and the prostate in total 30 Gy. The clinical symptoms started to resolve immediately, and the disappearance completely within 7 months. This case illustrated that urgent irradiation was effective for broad metastatic spinal tumor with rapidly progressive neurological deficits.

[Relationship between cardiac natriuretic peptide (ANP/BNP) and fluid intake in patients with subarachnoid hemorrhage].

Several authors described elevated natriuretic peptides, atrial natriuretic peptide(ANP) and brain natriuretic peptide (BNP), in patients with subarachnoid hemorrhage(SAH), which were account for inappropriate antidiuretic hormone(SIADH) or cerebral salt wasting syndrome(CSW). Although the secretion of natriuretic peptide depends on the total blood volume, central venous pressure, and cardiac output volume, the volume of fluid intake in patients with SAH had not been taken in consideration in previous report. We here examined the relationship between fluid intake and the natriuretic peptides in two cases without cardiac failure. ANP elevated 2 or 3 days after SAH and remained in normal range for 2 weeks. BNP elevated when the volume of fluid intake was increased, and BNP did not elevate during the periods with lower fluid intake. Several authors proposed the possibility of iatrogenic factor in natriuresis after SAH and these results supported this opinion.

Synthesis and antibacterial activity of 2,2'-dithiobis(benzamide) derivatives against Mycobacterium species.

A series of compounds, which are analogues of 2,2'-dithiobis(benzamide), were synthesized and tested for in vitro antibacterial activity against Mycobacterium tuberculosis H37Rv including resistant strains against streptomycin, kanamycin, or isonicotinic acid hydrazide. MICs of these compounds against atypical mycobacteria, Mycobacterium kansasii and Mycobacterium intracellulare were also examined. Structure-activity relationships were found in a series of (acyloxy)alkyl ester derivatives depending upon the length of alkyl carbon chain. The MIC of the most potent compound, 2,2'-dithiobis[N-[3-(decanoyloxy)propyl]benzamide] [56] was superior or at least equivalent to streptomycin, kanamycin, and ethanbutol. All the compounds showed no cross-resistance between the current antitubercular agents.