Treatment Options of Metastatic Brain Tumors from Hepatocellular Carcinoma: Surgical Resection vs. Gamma Knife Radiosurgery vs. Whole Brain Radiation Therapy

OBJECTIVE: Although metastasis of hepatocellular carcinoma to the brain is uncommon, it is associated with a very high mortality rate and most patients usually expire within 1 year after brain metastasis. The aim of this study is to identify the effectiveness of the active interventions such as gamma knife radiosurgery or surgical intervention for these patients. METHODS: We retrospectively reviewed the medical records and imaging data of 59 patients with metastatic brain tumors from hepatocellular carcinoma from May 2004 to September 2012. The study included patients with available clinical and radiological data who had been diagnosed with metastatic hepatocellular carcinoma of the brain, confirmed by magnetic resonance imaging. The overall survival time was analyzed and compared according to each risk factor. RESULTS: The mean age at diagnosis of metastatic brain tumor was 52.2 years (14-77). The mean follow-up duration was 13.3 weeks (0.1-117.6). Overall median survival was 4.3 weeks (95% confidence interval, 2.2-6.4). The results from an analysis of clinical factors related to survival revealed that treatment modalities were significantly related to the patient's survival (log rank, p=0.006). Twenty patients (32.8%) experienced tumor bleeding, and the survival time of the patients with tumor bleeding tended to be shorter, although the result was not statistically significant (log rank, p=0.058). Hepatic reserve, by Child-Pugh classification, was grade A in 38 patients (64.4%), grade B in 16 patients (27.1%), and grade C in 5 patients (8.5%), and was significantly related to the patient's survival (log rank, p=0.000). CONCLUSION: Although patients with metastatic brain tumors from hepatocellular carcinoma showed poor survival, active intervention including surgical resection or gamma knife radiosurgery may result in better survival, especially if patients have preserved liver function.

Cerebral Arteriovenous Malformations in Pediatric Age:A Clinical Analysis of 164 Consecutive Cases / 대한뇌혈관외과학회지

OBJECTIVE: This study was designed to understand the clinical characteristics and to establish therapeutic options for arteriovenous malformations (AVM) in a pediatric age (1~8 year old) group. METHODS: We reviewed programmed clinical data, patients'medical records and imaging studies of the 164 pediatric AVM patients who were managed at Yonsei University Medical Center from 1975 to 2004. Clinical presentation, location, Spetzler-Marin grade, treatment modality and outcomes were analyzed. RESULTS: Ninety-one patients (55.5%) were male and seventy-three (44.5%) were female. The most common presenting symptom was hemorrhage (119 patients, 72.6%). In others the symptoms were seizure (26 patients, 15.9%), hemorrhage with seizure (6 patients, 3.6%), focal deficit (4 patients, 2.4%), headache (8 patients, 4.9%) and incidental (1 patients, 0.6%). The locations of AVMs were cerebral convexity (110 patients, 67.1%; 21 frontal, 40 parietal, 23 temporal, 23 occipital), basal ganglia and thalamus (24 patients, 14.6%), corpus callosum (12 patients, 7.3%), sylvian (3 patients, 1.8%), cerebellum (13 patients, 7.9%) and two patients had brain stem lesions (1.2%). According to the Spetzler-Martin grading system, at admission grade II and III AVMs were the most common lesions in our series (43.9% and 33.5%, respectively). The patients were treated with microsurgery in 70 patients (42.7%), radiosurgery in 87 patients, (53.0%), combined treatment in 5 patients (3.1%) and embolization in only 2 patients (1.2%). The average follow-up period was 4.8 years and the overall outcome was considered good in 139 patients (84.8%), fair in 18 patients (11.0%), and poor in 4 patients (2.4%), with 3 patients having died (1.8%). The causes of unfavorable outcomes were initial insult (4 patients), radiation necrosis (1 patient), bleeding during the latent interval (1 patient) and systemic complication (1 patient). CONCLUSION: Hemorrhagic presentation and deep brain (thalamus and ganglia) lesions were more common in the pediatric patients compared to adult patients. The treatment of choice for hemorrhagic pediatric AVMs is surgical excision, even for deep seated or eloquent area lesions. Radiosurgery is recommended especially for the non-hemorrhagic lesions, particularly in deep seated or eloquent area lesions. Regular imaging studies are necessary for detection of AVM regrowth, and signs of hemorrhage should be monitored during the latent period.

A Study on Monitoring of Pyramidal Motor Evoked Potential Excluding Extrapyramidal Systems in the Rat Spinal Cord / 대한해부학회지

The motor evoked potential (MEP) elicited by transcranial or transcortical stimulation has been advocated as a method of monitoring the integrity of spinal efferent pathways in the various animal models. It was also defined that MEPs were composed of a short latency, direct, synapse free D-wave and a later latency, indirect, synapse mediated I-wave. The authors designed to study pyramidal MEP in rat, because we would understand and use pyramidal MEPs as human efferent spinal pathway monitoring tools during the spinal cord operation in the future. Thirty-two Sprague-Dawley rats were involved in this study. A stainless steel electrode was placed in the hindlimb motor cortex. It was stimulated with 1~4 Hz mono-rectangular pulse waves and 0.1~5 mA in stimulation intensity during short duration. Teflon coated wire electrode was used to record MEP in the spinal cord. MEPs after internal capsule cutting and post-mortem MEPs were recorded finally to exclude the possibility of extrapyramidal MEPs. At the level of medulla oblongata and seventh cervical segment (C7), the recorded MEPs showed positive-negative-positive complex D-wave and a large I-wave activated by presynaptic fibers and monosynaptic depolarization of pyramidal cells. But, at eighth thoracic segment (T8), only large negative I wave, in which prolonged D wave would be included, was recorded. From cortex to seventh cervical spinal cord at 1 mA stimulation intensity, the estimated conduction velocity of D-wave was approximately 11.01+/-0.20 m/sec and that of I-wave was 2.53+/-0.02 m/sec in this study. After internal capsule cutting and postmortem state, both D and I waves were disappeared. Loss of waves indicated that not the extrapyramidal pathway potentials but the pyramidal pathway potentials were recorded selectively. This successful preferential activation of pyramidal MEP in rat demonstrated the possibility of clinical availability during the spinal, especially cervical motor tract monitoring and evaluation. If repeated study would be continued in human, MEP will be more available in clinical field.

The Renewal of Cognizance Criteria for Work Compensated Disease in Spondylolisthesis

No abstract available.

A Case of Huge Mature Teratoma Developed in the Middle Cranial Fossa: A Case Report

A case of intracranial mature teratoma found in a 35-year-old man is reported. This tumor was originated from the left middle cranial fossa. The tumor was exceptionally huge and MRI showed whirling appearance of intratumoral content. It seems that the temporal location permitted the tumor to grow into a huge size for a squamous epithelium, sebaceous glands, bony spicules, and neuroepithelial tissue, which were compatible with histologic findings of teratoma. It is very unusual for a teratoma to occur in the middle cranial fossa, whereas most of the teratomas are located in the midline structures, such as the pineal or the suprasellar region.

The Characteristic and Origin of Motor Evoked Potential in Rats

Motor evoked potential(MEP) produced by cortical surface or transcranial stimulation has evolved as a new clinical and experimental tool to monitor the integrity of motor pathways and to map motor cortex. Clinical assessment of motor system using MEP has further advanced with recent development of the magnetic stimulator. The primary concept using MEPs for test of motor pathways was based on the assumption that pyramidal neurons in the motor cortex are activated by electrical stimulation applied on the cerebral cortex and synchronized compound action potentials are conducted mainly along the corticospinal tracts in the spinal cord. However,recent studies indicated that the origins of the Meps in non primates may differ from those previously believed. In order to use MEPs as a clinical or experimental tool, it is essential to clarify the origin of MEPs. Therefore, goals of this study were : (1) to investigate the origin of MEPs, and (2) to design the most reliable but simple method to evoke and monitor MEPs. In a total of fifteen rats, MEPs were produced by cortex to cortex stimulation and were monitored using a pair of epidural electrodes. Using varying stimulus intensities, the amplitudes and latencies of MEPs were statistically analyzed. The latencies and amplitudes of the MEPs in these animals showed surprisingly large standard deviations, which were partially resulted in these animals showed surprisingly large standard deviations, which were partially resulted from convergence of neighboring waves during high stimulation intensities. Wave forms of MEPs were also varied greatly depending on the position of recording electordes. At low stimulus intensities, most consisten MEPs were obtained when the stimulating electrodes were placed on the hard palate and the temporal muscle, not on the motor cortex. This observation indicates that the primary source of MEPs is not the motor cortex in the rat. When the potentials generated by direct stimulation of motor cortex and those generated by reticular nuclei were monitored epidurally in the same preparation using the same electrodes, these potentials generated by different sources actually identical in their latencies and wave forms. However, the threshold stimulus intensities evoking these potentials were quite different in the two metholds. The threshold was much lower to evoke potentails by reticular nuclei stimulation. It suggests that MEPs are geneated by the reticular nuclei or brain structure located in the brain stem. The observation that the motor cortex play no major roles in generating MEPs was confirmed by sequential sections of neural axis from the motor cortex to brain stem in three rats. All these findings suggested that neither direct motor cortex stimulation not transcranial stimulation did evoke MEPs originating from the motor cortex in rat. These stimulating methods activate reticular nuclei by stimulus current spread to the brain stem. Since the reticular formation plays an important role in motor function in rats, MEP originated from reticular nucleus can be an important testing of the motor function in rats. Moreover, transcranial stimulation of the brain is technically easy. This technique producing MEPs originated from reticular nucleus can be useful to monitor the integrity of motor pathways.

The Intraspinal Pathways Conducting Motor Evoked Potentials in Rats

Recently, motor evoked potential(MEP) using cortical surface of transcranial stimulation have been used to monitor the integrity of motor pathways and map motor cortex in human and animal. The primary concept using motor evoked potentials(MEPs) for test of motor pathways was based on the assumtion that pyramidal neurons in the motor cortex are activated by electrical stimulation applied on the cerebral cortex and synchronized compound action potentials are conducted mainly along the corticospinal tracts in the spinal cord. However, the origins and the descending pathways of these MEPs in small animals may be different from those of potentials evoked by intracortical microstimulation because of current spread. Our previous study revealed that the origns of the MEPs in rats differed from those previously believed and may be reticular nuclei. To further clarify those results and localize the intraspinal pathways conduction MEPs, consecutive vertical and/or horizontal sections of the spinal cord were performed at T9 cord level in twelve rats. MEPs were recorded at T2/3 and L2/3 before and after each section and sequential alterations of MEPs were observed. In six rats, the stimulation was alternated between the right and left cortex and the lateralities of conduction pathways were compared. All six cases showed no differences of MEPs and pattern of wave abolition after each section between right and left brain stimulation. The alteration of MEPs after each consecutive section was categorized by analyzing latency shift, amplitude change, and disappearance of waves. We divided a cross section of T9 spinal cord into forty-six squares. If one of the categorized changes occurrd after cutting an area, the appropriate score was given for the area since more change of waves meant more significant contribution of the cut area to conduction of MEPs. The score of twelev rats were summed in each forty-six spots and map showing the distribution of MEPs was constructed. The map revealed that MEPs were conducted along the wide area of ventral and lateral funiculus of the spinal cord but mainly along the medial portion of the ventral funiculus of the spinal cord but mainly along the medial portion of the ventral funiculus and ventral portion of the larteral funiculus through which reticulospinal and vestibulospinal tracts pass. No conduction of MEPs along the corticospinal tracts was confirmed. This finding supports the result of our previous study. However, this extrapyramidal MEP conducted along ventral spinal cord in addition to somatosensory evoked potential(SSEP) which is conducted along posterior funiculus can be useful to monitor the integrity of the whole spinal cord. Moreover, the extrapyramidal MEP can be more useful than pyramidal MEP in rats because the reticular formation plays a more important role in motor function and pyramidal tract is located in posterior funiculus.

Clinical Analysis of Traumatic Intracranial Hemorrhage

The authors analyzed 115 cases of head injury surgically treated in the Department of Neurosurgery, Yonsei University Medical College, in 1978. Among them, 18 patients had another significant combined injury in the body. Mortality of them was twice more than of the group without combined injury. Protection of brain from circulatory disturbance, hypoxia, fat embolism, etc. is chief point of early treatment of multiply injured patients. The most common cause of multiple injuries involving head injuries was traffic accident. Mortality of the group diagnosed with CT scan was lowest. Intervals between the injury and operation were within 24 hours in almost them.