Diffusion tensor tractography provides useful information regarding the surgical strategy for brain tumors. The goal of the present study was to analyze relationships between visual field deficits and the locations of brain tumors compared with optic tracts as visualized by tractography, and compared with the calcarine fissure.
Subjects comprised 11 patients with brain tumor in the occipital lobe or atrium of the lateral ventricle who underwent surgery between October 2006 and February 2009. Tumors were categorized as Type A, with almost all the optic tract in the occipital lobe or atrium of the lateral ventricle running close to and stretched by the brain tumor; and Type B, with the optic tract running at least partially distant to the brain tumor and remaining unstretched.
Those type A optic tracts that were laterally compressed by brain tumors (Cases 1-3) displayed hemianopsia after surgery. When the brain tumor was located rostro-medial to the calcarine fissure and optic tracts were compressed caudally by the tumor, lower quadrant hemianopsia remained after surgery (Cases 4, 5). In other cases, the visual field remained or improved to normal after surgery.
The relationship between optic tracts or the calcarine fissure, and brain tumors in the occipital lobe or atrium of the lateral ventricle is related to visual field deficits after surgery. In particular, those Type A optic tracts that are compressed laterally show hemianopsia of the visual field after surgery.
"Cerebral oedema is a common complication of metastatic brain tumours , which results in an increase in the water content within the skull and subsequent increase in intracranial pressure. This may lead to localised ischaemia, brain herniation, seizures, blindness, cognitive deficit, weakness, headaches, aphasia and ultimately death if blood perfusion of the brain is critically compromised (Mukand et al., 2001; Ayata and Ropper, 2002; Marchi et al., 2007; Shinoura et al., 2010). "
[Show abstract][Hide abstract] ABSTRACT: Dexamethasone, the standard treatment for peritumoral brain oedema, inhibits classical inflammation. Neurogenic inflammation, which acts via substance P (SP), has been implicated in vasogenic oedema in animal models of CNS injury. SP is elevated within and outside CNS tumours. This study investigated the efficacy of NK1 receptor antagonists, which block SP, compared with dexamethasone treatment, in a rat model of tumorigenesis. Dexamethasone reverted normal brain water content and reduced Evans blue and albumin extravasation, while NK1 antagonists did not ameliorate oedema formation. We conclude that classical inflammation rather than neurogenic inflammation drives peritumoral oedema in this brain tumour model.
Journal of neuroimmunology 06/2012; 250(1-2):59-65. DOI:10.1016/j.jneuroim.2012.06.001 · 2.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The present study evaluated the efficacy of diffusion tensor imaging (DTI)-based tractography in the surgery of brain tumors adjacent to the optic radiation. Of the 14 surgical cases included, 11 had metastatic brain tumors and 3 cerebral gliomas. Additionally, 4 of the 14 patients had pre-operative visual field defects, while the remaining 10 patients experienced no visual impairment. The optic radiations on the lesion side were evident in all 14 patients. On the basis of these tractographic findings, we employed optimal surgical approaches in each patient to avoid injury to the eloquent neural structures, including optic radiation, during surgery. Successful surgical resection was performed in all 14 patients. Of the 14 patients, 2 with visual field defects during the pre-operative period showed improvement in their visual field, and the remaining 12 patients experienced no visual deterioration. DTI-based tractography thus is a feasible modality for the surgical planning of brain lesions adjacent to the optic radiation.
[Show abstract][Hide abstract] ABSTRACT: Little is known about optic radiation (OR) injury in patients with traumatic brain injury (TBI). We report on a patient who showed an OR injury on diffusion tensor imaging (DTI) following traumatic epidural hematoma (EDH). A 38 year-old man with TBI and 7 age-matched normal subjects were enrolled in this study. The patient had fallen down stairs while in an alcohol intoxicated state. He underwent a craniotomy following diagnosis of traumatic EDH in the left temporo-parietal lobe on brain CT. He complained of right bilateral homonymous hemianopsia, which was confirmed on the Humphrey visual field test. No lesion on the left OR was observed during brain MRI. We were not able to reconstruct the fiber tractography for the left OR in this patient. We found that the left OR had been injured most severely around the midportion between the lateral geniculate body and occipital pole. We determined that DTI would be a useful technique for detection of an OR injury in patients with TBI. Therefore, we believe that DTI should be performed along with conventional brain MRI for patients with visual field defects following TBI.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.