Direct Microsurgical Clipping of Cavernous Carotid Artery Aneurysms

We have recently operated directly on two patients with multiple aneurysms including cavernous carotid artery aneurysms(CCAAS). The pterional extradural transclinoidal and intradural transcavernous approach was used for CCAAS in two patients. Both two CCAAS could be clipped in Dolenc's anteromedial triangle between the optic nerve and the IIIrd nerve. There was no surgical mortality and morbidity was minimal. The combined extradural and intradural transcavernous approach was very useful and safe for direct clipping of CCAAS.

Comparative Analysis of Management of Intracerebral Hematoma

Retrospective analysis of 46 patients with intracerebral hematoma showed that the attack was most frequent in sixth decade and more prevalent in female. The most common cause of the attack was hypertension(80%) and the site of hemorrhage was putamen 32%, thalamic area 15%, subcortical area 7%, cerebellum 17%, ventricle 3%, and brain stem 4%. Mortality of total cases was 36% and there was no difference of mortality in both conservatively or operatively treated group(38% in conservative group, and 35% in operative group). The prognosis of the patient was unfavorable in the group of poor pretreatment Glasgow coma scale(GCS) and those of cases demonstrated more than 30cc of hematoma on computerized tomography(CT) of the brain. The improvement of GCS after management was better in operative group than in the conservative group.

Direct Microsurgical Repair of Traumatic Carotid-Cavernous Fistula

The case of a 55-year-old male developed high flow carotid-cavernous fistula(ccF) after head trauma was successfully treated by a direct microsurgical approach to the cavernous sinus. The cavernous sinus was approached through Dolenc's anteromedial and paramedical triangle by a combined extradural and subdural route. A single tear in the wall of horizontal segment of the cavernous carotid artery was obliterated using Sugita clip while temporary clips were placed on the supraclinoid and the petrous portion of the internal carotid artery.

A Combined Extra and Intradural Direct Microsurgical Approach to Tumors Involving the Cavernous Sinus

A series of seven tumors involving the cavernous sinus operated on from February 1990 to March 1991 is reported. There were 3 meningiomas, 2 neurilemmomas, 1 cavernous hemangioma, and 1 pseudotumor. After a standand pterional craniotomy, bone is removed from the posterior part of the orbital roof, the optic canal, the lesser sphenoid wing, and the anterior clinoid process. Next important step of the extradural stage is unroofing petrous bone over the internal carotid artery, if the proximal control is needed, after the exposure of the foramen rotundum, ovale, and spinosum. Intradural stage is consisted of sectioning of carotid rings and identification of III, IV and V cranial nerves which is associated with removal of tumors through various triangles according to the size and location of the tumor. None of patients died or suffered permenent neurologic deficit postoperatively.

Two Cases of Intraventricular Arachnoid Cyst

Two rare cases of intraventricular arachnoid cyst locating in the posterior portion of the third ventricle are presented. A diagnosis was based on the radiological and operative findings and the microscopic features. Cyst wall fenestration by a direct approach resulted in good outcome. The orgin and the management of arachnoid cyst are discussed.

Two Cases of Intraventricular Arachnoid Cyst

Two rare cases of intraventricular arachnoid cyst locating in the posterior portion of the third ventricle are presented. A diagnosis was based on the radiological and operative findings and the microscopic features. Cyst wall fenestration by a direct approach resulted in good outcome. The orgin and the management of arachnoid cyst are discussed.

The Effect of Radiation Therapy on Oligodendrogliomas / 대한치료방사선과학회지

From April, 1983 through April, 1989, we have treated histologically proven 21 patients with oligodendroglima using 6 MV linear accelerator at the Division of Radiation Therapy, Kangnam St. Mary's Hospital Catholic University Medical College. These are 8% of the irradiated 246 primary brain tumors during the same period. To investigate influencing factors on the survival of irradiated 21 patients with oligodendroglioma, we analyzed the cerebral location of the nvolvements, initial symptoms, CT findings and survival rates, retrospectively. One case was lost to flow up and excluded from survival data. Of the 21 patients, thirteen were male and 8 female. Ages ranged from 5 to 68 years with a median age of 38 years. Radiation doses varied from 3960 cGy to 6480 cGy and were given for 5 to 8 weeks. All but one were supratentorial. The involvement of the frontal and parietal lobes were 10 (48%) patients in each and temporal lobe in 8 (38.1%). Histological diagnosis was made by stereotactic biopsy in 3 and postoperatively in 18. The type of surgery was divided into partial, subtotal and total resection in 7,9 and 2 cases respectively. In 6 cases, chemotherapy was also tried during or after radiation therapy. Major presenting respectively in decreasing order. In CT analysis, low density (62%), cystic mass (33%), calcification (66%) and positive contrast enhancement (42.8%) were observed as the highest frequency. Mean survival duration after radiation therapy was 38 months (K-M methods). We could not achieve statistically significant factors influencing on the survival rate after radiation therapy for oligodendrogliomas by one or two tail test.

Microsurgical Endarterectomy for Symptomatic Carotid Artery Stenosis

Five patients with symptomatic carotid artery stenosis were treated with microsurgical carotid endarterectomy from January 1988 to December 1990. All patients but one case with major stroke have been improved remarkably after surgery. During the surgery, the use of surgical microscope and electroencephalographic recording seemed to be very useful and beneficial not only for meticulous surgical procedure but also for monitoring of cerebral tolerance in carotid artery cross clamping.

Evaluation of Reversibility of Cerebral Infarction by Somatosensory Evoked Potentials in Experimental Focal Cerebral Ischemia

Somatosensory evoked potentials(SSEP's) are commonly employed to monitor cerebral and spinal cord function in patients with various lesions in the nervous system. In this study, we evaluated SSEP's as a means of measuring not only neurophysiological function but also the alteration of blood folw in the territory of cerebral ischemia. We examined SSEP's and regional cerebral blood flow(rCBF) in the bilateral suprasy1vian gyri following unilateral middle cerebral artery(MCA) occlusion in 15 cats(Group II). The duration of arterial occlusion was 30 minutes followed by 1 hour of recirculation. Five additional cats served as sham-operated groups(Group I). The animals in Group II were divided into 2 subgroups according to the change of the observed rCBF in the ipsilateral hemisphere. Immediately after MCA occlusion, rCBF decreased from around 50 to 14mg/100g/min. Decreased rCBF was remained below 20ml/100g/min throughout the ischemic period in 6 cats(Group IIb), and in the remaining 9 cats, the decreased rCBF was increasing during ischemia although the blood flow was subnormal(Group IIa). The recovery of rCBF during recirculation was faster in Group IIa than in Group IIb. In Group IIa and IIb, there was a significant slowing of the interpeak latency between dorsal column nuclei(Fz) and the major negative deflection(MN) (P<0.05) in the ipsilateral hemisphere and a precipitous decrease in the amplitude of the ipsilateral P1-MN complex immediately after occlusion(P<0.05). In Group IIb the suppressed SSEP's did not show any recovery during ischemia, and recovered late during recirculation. In Group IIa the suppressed SSEP's tended to recover during recirculation. In Group IIa the suppressed SSEP's tended to recover during ischemia and recovered early during recirculation. SSEP's were not completely abolished throughout the experiment in any experimental grup. The relationship between the changes in rCBF and amplitude of SSEP's in the ipsilateral hemisphere was significant(r=0.943, P<0.05) during occlusion of the middle cerebral artery in Group IIa. However there was not any other relationship in the other groups or among other wave components. These results indicate that the suppression of SSEP's and their failure to recover during focal cerebral ischemia correlate with the lack of collateral circulation. Furthermore, SSEP's can be useful means to evaluate the reversibility of cerebral ischemia, which may be decided by existence of collateral circulation. And it appers that the time threshold for abolition of SSEP's is more than 30 minutes in focal cerebral ischemia in the cat.

Zygomatic Temporopolar Approach to High Placed P1 Aneurysm

The authors describe the case of a 57-year-old female who developed subrachnoid hemorrhage secondary to rupture of posteriorly projecting, high placed aneurysm of the proximal posterior cerebral artry. This aneurysm was treated easily and successfully with the zygomatic temporopolar approach which was modification of the temporopolar approach proposed by Sano by detaching the zygomatic arch to get a wide and flexible operating field.

3 Cases of Coincidental Cerebral Aneurysm with Pituitary Tumor

We report three cases of coincidental cerebral aneurysm with pituitary tumor. In our hospital the incidence of such cases was 4.4% of 68 patients with pituitary tumors from March, 1970 to October, 1990. Cases No. 1 was a 47-year-old female suffering from progressive loss of visual acuity. Preoperative brain C-T scan and angiographies revealed unruptured posterior communicating aneurysm with pituitary tumor. Case No. 2 was a 39-year-old male suffering from headache after head trauma with acromegaly. Preoperative brain C-T scan and angiographies appeared unruptured anterior communicating aneurysm and pituitary tumor. Case No. 3 was a 62-year-old female suffering progressive loss of visual acuity and headache. Left middle cerebral artery aneurysm and pituitary tumor were found by preoperative brain C-T scan and angiographies. All cases were operated by transcranial route and performed tumor removal after primary clipping of aneurysm. Postoperatively remained tumor of all cases was treated by radiosurgery successfully.

Large Aneurysm of Azygos Anterior Cerebral Artery: Case Report

A case of large aneurysm of azygos anterior cerebral artery(Azygos ACA) is reported. This 52-year-old male patient became unconscious suddenly on working. The CT scan demonstrated small amount of hemorrhage in the interhemispheric fissure and basal cistern and huge intraventricular hematoma with marked dilatation of all ventricles. Emergency external ventricular drainage was done and his consciousness recovered to the level of possible spontaneous eye opening. 4-vessels angiography done a month later revealed a large revealed a large fusiform aneurysm at the bifurcation of distal end of azygos ACA. Authors preferred interhemispheric approach and clipped the aneurysmal neck uneventfully. Despite the successful clipping of the aneurysm confirmed by postoperative angiography, preoperative mutism, spastic weakness of lower extremities and urinary incontinence didn't recovered. This case suggests that preoperative neurological status is no less critical to the postoperative outcome than surgical technique. This is the first case of large aneurysm at this site so far as we know.

Histopathological Studies of Chronic Nerve Compression

Recently nerve entrapments or nerve root compressions are common clinical symdromes. However, a clear understanding of both pathophysiological and morphological changes is lacking and it may not be completely established in the experimental model for chronic nerve compression, compared with a surprising review of peripheral nerve exposed to various acute damage. Adult Sprague-Dawley rats weighing 250 to 300g were used as the experimental model to elucidate histopathological changes in chronic nerve compression, which were produced by banding the sciatic nerve(normally 1.2mm in diameter) with the length of 1cm silastic tubings with inner diameter, 0.6mm(Group I), 0.9mm(Group II) and 1.5mm(Group III) in each. Specimens were obtained for light and electron microscopic studies postoperatively at 1 and 3 months following by nerve conduction study. Grossly in group I, the sciatic nerve was compressed to approximately 50% of its normal in cuff area and in thin strand on distal part at 1 month and more progressed at 3 months. The sciatic nerve of group II demonstrated 75% of control and distal part in 50% compression at 1 month, but the nerve seemed not to be affected by tubing. Light microscopic findings revealed Wallerian degeneration and diminished large myelinated fiber particularly in the periphery of nerves with 34% of transverse nueral percentage in group I at postoperative 1 month. Above findings were progressed to epineurial scarring and fibrosis at 3 months. There were marked diminution and deformity in large myelinated fiber in group II, but it was not more severe than the ones of group I. Electron microscopic findings in this group revealed the appearance of small regenerating unit clusters and thinly myelinated fibers. In group III, histological findings were not much different from that of normal nerve. Nerve conduction study revealed the decrease in conduction velocity to mean 10 M/sex in group I at 1 month and no electrical conduction at 3 months. In group II, diminution of conduction velocity in 73% of normal range at 1 month was noted, and 82% at 3 months. These findings explain correspondingly the histopathological changes in part of chronic nerve entrapment syndromes and appeal the need of further investigation in this experimental model.

Brain Tumor Immunology: Part II : Immunotherapy of Malignant Brain Tumors

The prognosis of patients with malignant brain tumors has improved only slightly despite the combined use of surgery, radiation therapy, and chemotherapy. Immunotherapy offers some possibilities and hopes as a fourth modality for the treatment of cancers although it is still in the early stages of development. It is possible to classify immunotherapy within four generally accepted modalities : 1) restorative or nonspecific immunotherapy 2) adoptive immunotherapy 3) passive immunotherapy 4) active immunotherapy. The techniques of recombinant DNA, genetic engineering, cell fusion and hybridoma production, and molecular biology will make these therapeutic approaches more successful and as the clinical applications expand the skillful cancertherapist will become increasingly familiar with these treatments and the problems associated with their use.

The Clinical Analysis of Surgical Treatment in the Medically Intractable Seizure

We performed callosotomy and amygdalo-hippocampectomy in medically intractable seizure patients. Symptom duration of these patients was over 2 years and seizure was not controlled with anticonvulsants in spite of high level in drug monitoring according to their seizure type. 7 patients with generalized epilepsy were treated by anterior callosotomy and 8 patients with temporal lobe epilepsy were treated by amygdalo-hippocampectomy. Anyone of these patients were not dead and discovered permanent complications. And so these methods, anterior callostomy and amygdalo-hippocampectomy seems to be relatively safety and effective methods in treatment of medically intractable seizure.

Successful Treatment of a Spinal Intradural Arteriovenous Fistula

An 18 year-old male patient presenting with progressive paraparesis was found to have a spinal arteriovenous fistula at the thoracolumbar vertebral level. The lesion consisted of a direct communication of the anterior spinal artery with a distended arterialized vein that drained mostly superiorly to the thoracic cord and simulated a long dorsal lesion. The patient was successfully treated by surgical excision of feeding artery and draining vein including fistula at the L1-3 vertebral level. Ischemic damage of the spinal cord due to venous hypertension is suggested as the cause of the clinical manifestation.

The Effect of Corpus Callosotomy on the Electoroencephalography in the Experimentally Induced Epileptic Rats

In order to study effect of corpus callosotomy for epileptic lesions located at sensory-motor cortex/cortices, changes in amplitude, frequency of background activity and frequency of abnormal discharges of postcallosotomy electroenencephalography(EEG) recordings were observed in the crystal penicillin induced epileptic models of rats. In control group of 10 rats, simple right(craniotomy was) done and needle electrodes were bilaterally inserted into parietal and occipital scalp, connected to EEG recording system. Experimentally induced epileptic group was obtained by instillation of 1-2 drops of crystal penicillin solution(800,000 IU/ml) at right parietal area(20 rats). Postcallosotomy group was consisted of the animals streotactically performed callosotomy with blunt ended stainless steel, sized 3 mm, width and 0.5 mm, thickness(20 rats). Preoprative and postoperative EEG recordings were obtained in each animals over 20 minates. The results were as follows; 1) Bialteral synchronous epileptic discharges were shown in experimetally induced epileptic group, which compared to control group. 2) Section of the corpus callosum caused the abolition of bilateral synchronous epileptic discharges, when compared to experimentally induced epileptic group. 3) Frequency of abnormal discharges in the contralteral hemisphere was more decreased than crystal penicillin-instillated lesion in postcallosotomy group. 4) The Background activity of postcallosotomy group was slower than control group. From the results of EEG analysis, corpus callosum might paly a important role in formation of bilateral synchronous discharges and callosotomy was seemed to be an effective method to control crystal penicillin induced epileptic rats, which had epileptic focus in sensory-motor cortex.

Preliminary Experience in Stereotactic Radiosurgery with the Linear Accelerator

It was already reported in else where that a standard linear accelerator, with only slight modification can function in a manner similar to Leksell's Gamma unit device in the treatment of inoperable deep seated intracranial lesions. Using collimated narrow beams, a localization system and special computer programs for precise patient positioning and a high concentration of irradiation dose within the lesions, eleven patients with AVMs and brain tumor have now been treated since 1988. The 6 MeV linear accelerator and Hitchcock stereotactic frame was used of the all procedures. In 10 of the 11 patients, no side effects occurred. The first 7 patients, who could be observed 3 months or longer have been studied radiologically and clinically. In 6 patients marked decrease in contrast enhancement and sometimes dramatic clinical improvement was achieved. In one case a marked increase of the surrounding brain edema occurred 7days after radiosurgery, who was operated on. The radiantion dose was based on the volume, location and radiosensitivity of the lesion which ranged 15-40 Gy.

Prolonged Ischemic Cerebral Infarct in the Rat after Middle Cerebral Artery Occlusion: Part 2:Effect of the NMDA Antagonist, MK-801, Upon Ischemic Evolution

Excessive activation of the N-methy-D-aspartate(NMDA) subtype of glutamate receptor, has been implicated in the sequence of neurochemical events which results in irreversible neuronal damage in cerebral ischemia. The effect of the NMDA antagonist upon the amount of ischemic brain damage has been already assessed by some investigators. But most of them were performed only in acute ischemic models. In the light of clinical experiences, it's neuroprotective effect is much more important in the prolonged ischemic model. So, authors produced the permanent occlusion of the left middle cerebral artery(MCAO) and sacrificed the animals 48 hours after the occlusion to observe the neuroprotective effect of the NMDA antagonist, MK-801, in the maturated condition of ischemia according to the previous PART I experiment. MK-801 was administered 2 times, intravenously 1 hours prior to MCA occlusion(0.5 mg/kg) and intraperitoneally 1 hour after the induction of ischemia(5 mg/kg) to maintain proper concentration of the drug. CBF was measured by hydrogen clearance methods. Areas of brain infarction were delineated by tetrazolium salt at the preselected 8 coronal levels of forebrain and measured on scale diagrams by a plannimeter. MK-801 had no effect on the cardiopulmonary function. In the control, the basal value of CBF was around 118 ml/100 g/min. Immediately after MCAO, CBF of the ipsilateral cortex was reduced to 13.3+/-2.6 ml/100 g/min and not recovered until the end of the experiment. But CBF of the contralateral cortex was maintained in the basal value throughout the experiment. In the treated, immediately after the intravenous administration of the drug. CBF of both frontal cortices was reduced to 15 to 20% of the basal value(P<0.001), and the reduced CBF was noted even after MCAO, comparing to the control, but 24 hours later the reduced CBF of the contralateral cortex recovered to the basal value. Treatment with MK-801 reduced the total amount of ischemic damage in the cerebral hemisphere(15.82+/-2.41 versus 10.66+/-1.33 cm, P<0.001) and the cerebral cortex(11.0+/-3.73 versus 6.30+/-1.6 cm, P<0.001). But the effect on the caudate nucleus was minimal. This experiment provides evidence for the potency of the glutamate antagonist, MK-801, in reducing ischemic brain damage, despite the result was obtained 48hours after MCAO. And the anti-ischemic effect of MK-801 in the experiment could not be attributed to by improvement of blood flow to the hypoperfused cerebral tissue.

Effect of Rapid and Slow Infusions of the Mannitol on Regional Cerebral Blood Flow and Brain Edema in Focal Brain Compression of Cats

The aim of the present study has been to examine the effect of mannitol on regional cerebral blood flow(rCBF) and brain edema both at normal and increased intracranial pressure and to determine which of two infusion methods, rapid infusion or slow infusion of mannitol, has better effect on brain compression. Thirty five adult cats weighting between 2.7 and 4.2 kg were used in this study. The animals were divided into four groups: Mannitol administered normal control(n=5), brain compression(n=10), rapid mannitol treated-brain compression(n=10) and slow mannitol treated-brain compression groups(n=10) respectively. A small balloon connected to a fine polyethylene tube was placed in the epidural space of the right frontal region through a small burr hole and inflated with on ml of distilled water in increment of 0.2 ml to simulate the expanding mass. The measurements of rCBF and electroencephalography(EEG) activity were carried out in each animal. Mannitol was given in bolus of 1g/kg body weight via the femoral vein and two methods of mannitol infusion were used as rapid infusion which was infused the mannitol within 3 min and slow infusion, infused within 15min. The rCBF was measured by hydrogen clearance method and the brain edema was measured by gravimetric technique. In brain compression group, the ICP rose immediately following brain compression to 133.00+/-9.49 mmH2O from 78.00+/-11.35 mmH2O and maintained the elevation during the experiment. Treatment with mannitol in brain compression animals, decreased the ICP at 5 min after infusion of mannitol, and the decreased ICP was maintained for one hour. Brain compression animals showed a significant reduction of rCBF by 38% and 46% in right parietal lobe at the 60 min and 120 min after brain compression, respectively. In mannitol treated brain compression animals, the administration of mannitol made the reduced rCBF increase to baseline value at 30 min after treatment and the increased rCBF value was maintained for one hour. There was generalized brain edema, as judged by a decreased specific gravity in the brain compression, which was maximal close to the brain compression site. The severity of the brain edema was less in the mannitol treated brain compression group than in brain compression group. This study demonstrated that there was no significant different effects between rapid and slow infusion of mannitol in brain compression.