A Case of Brain Stem Anaplastic Oligodendroglioma with Exophytic Growth

No abstract available.

A Functional MRI Study of Brain Language Network in Korean Adult

OBJECTIVES: To report the results of functional magnetic resonance imaging (fMRI) experiment to delineate brain network for auditory language tasks in normal Korean adults. METHOD: Five normal right-handed Korean males, aged 20~33 years, were investigated using fMRI technique. Language tasks consisted of auditory listening and verb generation tasks. In fMRI, twenty slices were obtained for each functional volume using single shot echoplanar image sequences. Eighty-four volumes were obtained for each functional run. Data were motion corrected, coregistered, normalized, and statistically analyzed using SPM-96 software (Wellcom Department of Cognitive Neurology, Oxford, UK). RESULTS: Functional activation were detected in superior temporal region (coordinates: x= 64, y= 42, z=2) in the left side and superior to middle temporal lobe (coordinates: x=50, y= 20, z=2) in the right side for auditory listening task. Auditory verb generation task activated inferior frontal gyrus (coordinates: x= 56, y=16, z=14), superior temporal region, and medial frontal region in the left side. Right temporal lobe was also activated in the superior to middle temporal areas. Activation was more extensive in the left side for both language tasks. CONCLUSION: Our results can remarkably delineate cortical and subcortical regions subserved for auditory language processing. These results can be contributing to understand the underlying mechanism of language disorders in brain-injured patients and to investigate the pattern of reorganization of language network after rehabilitation.

Surgical Management of MRI-invisible Extratemporal Epilepsy

OBJECTIVE: The advent of high resolution magnetic resonance imaging(MRI) contributed to the preoperative localization of epileptogenic area. Even the discrete lesion visualized on MRI can be often correlated with seizure onset zone. If MRI does not, however, show any lesions in the extratemporal epilepsy, it imposes a significant challenge. This study is designed to evaluate the surgical treatment of extratemporal lobe epilepsy in which MRI does not show any lesion, to define the surgical strategy and to investigate the underlying pathology. METHODS: We studied the nineteen patients with MRI-negative extratemporal epilepsy who underwent resective surgery after careful preoperative investigation between 1993 and 1995. RESULTS: Scalp EEG could not lateralize the epileptogenic foci in 9 patients. Intracranial EEG recording was performed in all patients with successful localization: depth electrode study in 12, and subdural grid and strip study in 7 patients. Resection was performed in frontal(n=14), in parietal(n=3), and in multilobar area(n=2). Pathological findings comprised cortical dysplasia in 10, gliosis in 7, and collagenoma in one patients. The surgical outcome was classified as seizure free in 10, rare seizures in 2, significant reduction in 5, and no change in 2 patients. CONCLUSION: MRI-invisible extratemporal epilepsy can be managed surgically with promising results. Cortical dysplasia and gliosis are two major pathological findings in this context though MRI does not demonstrate any lesions.

Surgical Treatment of Focal Cortical Dysplasia

Cortical Dysplasia(CD) is increasingly recognized as a cause of intractable epilepsy since it can be easily diagnosed with high resolution magnetic resonance imaging(MRI). We analyzed 24 consecutive cases with cortical dysplasia who underwent resective surgery at our institute between September, 1992 and December, 1995. MRI was demonstrated to be a decisive tool to identify CD in 16 cases(66.7%). However, the remaining 8 cases(33.3%) were confirmed to have CD based on histological examination. Location of the lesion included temporal(n=9), central(n=5), multilobar(n=5), and frontal(n=5). Intracranial EEG recording was performed to delineate the epileptogenic zone in 16 cases:subdural grid(10 cases) and depth electrode(6 cases). Resection was performed in temporal(n=9), frontal(n=7), central(n=6), parietal(n=1), and multilobar(n=1). Complete resection was possible in 15(62.5%) and partial resection in 9(37.5%). Histological examination revealed dyslamination of cortical layers only(n=9), additional dysplastic neurons(n=7), and additional balloon cells(n=8). Surgical outcome was graded as seizure free(n=14:58.3%), rare seizures(n=3:12.5%), <50% reduction of seizure frequency(n=2:8%), and no change(n=5:20.8%) after mena follow-up of 12.7 months. The most influencing factor on the surgical outcome was the degree of completeness of resection(p<0.05). However, detectability of CD on MRI, severity of histological findings, age of seizure onset, and duration of seizure were not significantly related with the surgical outcome. High suspicion is required to detect the CD among the patients with intractable epilepsy and surgical strategies should be well-planned to improve the surgical outcome in the patients with CD.

A Case of Subependymal Giant Cell Astrocytoma associated with Tuberous Sclerosis(Case Report)

Subependymal giant cell astrocytoma is a very rare cerebral glioma and is known to be usually associated with tuberous sclerosis. We experienced a case of this tumor occurred at the wall of both lateral ventricles near the foramen of Monro in a patient of tuberous sclerosis who had symtoms and signs of hydrocephalus and other complex manifestations of facial adenoma sebaceum, huge fibroma on occipital scalp and hamartoma on the right retina. The masses were removed completely through transcallosal approach with microsurgical technique. The literatures are also reviewed.

Influence of Kallikrein on the Cerebral Blood Flow in Rabbits

It is known that in animals with increased intracranial pressure the cerebral perfusion is curtailed, but whether it is caused by deranged responsiveness of the cerebral vessel is not known. Thus, it was attempted in this study to find out the changes of cerebrovascular response to Kallikrein in the rabbits with increased ICP(20mmHg) under urethane-anesthesia. 1) intracarotid arterial kallikrein elicited increases in cerebral blood flow and decreases in blood pressure and arterial resistance. 2) Cerebral blood flow was significantly decreased in rabbits with increased ICP in comparison with the control rabbits. 3) Intraarterial kallikrein caused dose-depent increases of cerebral blood flow in both groups, but responses were significantly reduced in ICP-elevated group. 4) Kallikrein produced dose-dependent hypotensive effect in both groups with no significant difference between both groups. 5) Cerebrovascular resistance was greater in rabbits with elevated ICP(20 mmHg), but kallikrein induced decreases of cerebrovascular resistance in both groups to the same degree, 6) Above results suggested that increased ICP reduces the cerebral blood flow by increasing cerebrovascular resistance, but it does not modify the reponsiveness of cerebral vessel to kallikrein.