The anti-edema effect of edaravone, a free radical scavenger, was evaluated by magnetic resonance imaging in six patients with extensive hemispheric ischemic stroke. T2 relaxation time in the infarct core, the boundary zone of the infarct, and the noninfarcted hemisphere were calculated, and T2 mapping was performed before and after edaravone administration. Edaravone administration significantly decreased the mean T2 relaxation time in the boundary zone of the infarct from 121.5 ± 9.2 (mean ± standard deviation) to 114.5 ± 9.9 msec (p = 0.008), but not in the core from 142.3 ± 13.4 to 142.2 ± 18.5 msec (p = 0.97) or the noninfarcted hemisphere from 93.0 ± 3.7 to 93.1 ± 3.8 msec (p = 0.91). The T2 subtraction map clearly demonstrated shortened T2 relaxation time in the boundary zone of the infarct. The present results indicate that edaravone can salvage the boundary zone of the infarct and is a useful cytoprotective anti-edema agent.
Murin-double-minute 2 (MDM2) is an important negative regulator of the p53 tumor suppressor, and affects the p53 protein level and transcriptional activity. The genotype of the single nucleotide polymorphism in the promoter region of MDM2 (single nucleotide polymorphism [SNP] 309) is associated with the MDM2 protein expression level and the onset age of several types of cancer. The SNP309 genotype was investigated in 254 Japanese patients with glioma and 50 healthy subjects. The genotype frequency of SNP309 was T/T homozygous in 62 patients (24%), T/G heterozygous in 126 (50%), and G/G homozygous in 66 (26%) of the glioma patients, and was similar in the healthy subjects. The G/G ratio was higher in our Japanese subjects than in Western populations. Immunohistochemical study of glioma tissues showed that the G/G genotype was associated with higher expression of MDM2 protein compared to the T/T genotype, suggesting that SNP309 attenuates MDM2 protein expression in vivo. However, no association was found between the SNP309 genotype and the histological grade of glioma, age at disease onset, or p53 gene mutation rate. In our study population, SNP309 affected MDM2 protein level, but had no significant involvement in glioma tumorigenesis.
Intraoperative 5-aminolevulinic acid (5-ALA)-induced fluorescence guidance for resection of malignant brain tumors was correlated with histological examination to investigate false positive findings in 42 patients with malignant glioma and six patients with metastatic brain tumor. Patients received a single 1 g oral dose of 5-ALA 2 hours before surgery. The tumor site was illuminated with a laser with a peak wavelength of 405 ± 1 nm and output of 40 mW. Samples with strong fluorescence were obtained from the tumor bulk and samples with weak fluorescence from the tumor cavity. Fluorescence was observed in 36 of the 42 malignant gliomas and four of the six metastatic brain tumors. No tumor cells were found in fluorescent samples from six of the 36 malignant gliomas and all four metastatic brain tumors. Five of the six malignant gliomas were recurrent cases. Fluorescence was found in areas of peritumoral edema or inflammatory cell and reactive astrocyte infiltration. Intraoperative 5-ALA-induced fluorescence guidance is useful for the resection of initial malignant glioma since false positive results are rare, but only non-eloquent weak positive areas should be resected. In contrast, all weak positive areas of recurrent malignant gliomas must be resected. Weak positive areas of the peritumoral edema surrounding metastatic brain tumors should be removed carefully as false positive results are common.
A 64-year-old man presented with a rare sporadic hemangioblastoma arising in the left optic nerve manifesting as left visual disturbance gradually progressive over 5 years. Magnetic resonance imaging revealed a well-enhanced mass in the left optic nerve. Partial resection of the tumor was performed via the frontoorbital approach. The histological diagnosis was optic nerve hemangioblastoma. Hemangioblastoma must be considered in the differential diagnosis of optic nerve tumors even in the absence of other lesions associated with von Hippel-Lindau disease.
A 21-year-old man presented with a hemorrhagic pilocytic astrocytoma of the tectal plate manifesting as sudden onset of severe headache, vertigo, nausea, and vomiting. Computed tomography demonstrated acute hydrocephalus and hemorrhage within the brain stem and fourth ventricle. Magnetic resonance (MR) imaging revealed a dorsally exophytic tectal tumor as hypointense on the T1-weighted image and hyperintense on the T2-weighted image with contrast enhancement. Radical resection of the tumor was selected because of the unusual aggressive clinical course with hemorrhage and suspicion of malignant components. The tumor was totally resected via an occipital transtentorial approach using a neuronavigation system without surgical complications. The histological diagnosis was pilocytic astrocytoma. The patient was discharged home without neurological deficits on the 9th postoperative day. Twenty-three months after the surgery, follow-up MR imaging demonstrated no recurrence. Tectal plate pilocytic astrocytoma is rarely associated with hemorrhage but should be considered in the differential diagnosis of intracranial hemorrhage with acute presentation. Such exceptional tectal tumors should be resected radically and undergo histological examination to decide on further appropriate treatment.
A 51-year-old woman had been followed up for 10 years for recurrence of pilocytic astrocytoma 5 years after the initial treatment consisting of subtotal resection, chemotherapy, and radiation therapy. The patient presented with sudden onset of headache and vomiting. Computed tomography and T2*-weighted magnetic resonance imaging revealed hemorrhage in the tumor located in the right basal ganglia, thalamus, and hypothalamus. She underwent gross total resection of the lesion. Histological examination confirmed recurrent pilocytic astrocytoma with organizing hematoma and granulation tissue. Although neither symptomatic hemorrhage nor late benign recurrence is common, careful long-term follow up is necessary for patients with pilocytic astrocytoma.
An 80-year-old woman presented with primary central nervous system (CNS) lymphoma manifesting as progressive disorientation and loss of activity. She received three cycles of high-dose methotrexate. The tumor shrank after two cycles and her mental status improved, but she suffered tumor recurrence. The second-line treatment consisted of four cycles of rituximab but the tumor enlarged. She was then treated with three cycles of temozolomide. Magnetic resonance imaging revealed no evidence of disease. Her mental status and performance status improved, and she suffered no toxicity. She is able to pursue her daily life without recurrence after 16 cycles of temozolomide. Temozolomide may be effective against relapsed primary CNS lymphoma without causing neurotoxicity in the elderly.
A 53-year-old woman presented with a ruptured intramedullary aneurysmal dilatation fed by the anterior spinal artery associated with an arteriovenous malformation located in the ventral cervical spinal cord. She developed tetraparesis and respiratory dysfunction. The neurological deterioration was caused by hematomyelia due to the ruptured aneurysmal dilatation and progression of edema in the upper cervical spinal cord due to venous hypertension associated with additional hematoma in the medulla oblongata. Endovascular embolization of both C-1 and C-2 radicular arteries was performed with Guglielmi detachable coils, but components fed by small branches such as the radiculo-pial artery were not obliterated. Surgery was performed for extirpation of the arteriovenous malformation and cervical intramedullary hematoma, and excision of the aneurysmal dilatation through a transcondylar approach combined with vertebral artery transposition. Postoperatively, she overcame several complications such as pneumonia and endocarditis, and had only moderate weakness of the right upper and lower limbs. This case indicates that surgical intervention for high cervical intramedullary lesion may be very effective.
A 56-year-old man presented with a very rare true neurenteric cyst in the conus medullaris without evidence of vertebral or visceral anomaly manifesting as a 6-month history of mild low back and bilateral inguinal pain. No motor weakness was found in the bilateral lower extremities. He had also suffered dysesthesia in the bilateral feet for several weeks before admission. Lumbar spine magnetic resonance (MR) imaging demonstrated a cystic intradural extramedullary mass at the L1-2 levels without enhancement after gadolinium injection. MR imaging, computed tomography, and radiography detected no vertebral anomaly. Lumbar laminectomy at the L1-2 levels was performed and the lesion was incompletely removed. Histological examination showed the cystic wall lined with ciliated columnar epithelium. Neurenteric cyst should be considered in the diagnosis of isolated cystic mass lesion at the lumbosacral region even in the absence of vertebral or visceral abnormality.
A 66-year-old man presented with a parietal intradiploic encephalocele manifesting as dizziness in June 2001. Skull radiography showed lytic change involving the right parietal bone. Computed tomography with bone window showed bone destruction associated with the right frontal lesion. Magnetic resonance imaging demonstrated a lesion in the parietal intradiploic space continuous with the right frontal lobe. The lesion was located near the central sulcus, so surgical biopsy carried the risk of motor dysfunction. Single photon emission computed tomography (SPECT) showed the same pattern of cerebral blood flow as normal brain tissue, so the neuroimaging diagnosis was encephalocele. The present case indicates that surgery may not be necessary in the absence of symptoms and neurological deficits. SPECT is very useful to identify encephalocele.