Effect of Hydrocephalus and Skull Defect on the Pressure Volume Index

To study the effect of hydrocephalus and skull defect on the pressure volume index(PVI), PVI values were measured in 4 groups, total 23 cats. Five normal cats(group I : control group), five kaolin induced hydrocephalic cats(group II), six kaolin induced hydrocephalic cats with delayed hemicranicetony(group III) and seven kaolin induced hydrocephalic-hemicraniectomy cats(group IV) were used. In 4 groups, the effects of laterality of ventricular bolus infusion site, hydrocephalus and skull defect on the PVI values were evaluated. The measuremnets were performed 4 weeks after kaolin inhection in hydrocephalic groups(group II, III and IV). The laterality of ineusion site did not have satistically significant influence on the PVI valu in all 4 groups. Compared to group I, the PVI values in group II and III showed increasing tendency without significance. But in group IV, the PVI values showed statistically significant increase, and this seemed to be due to the biomechanical changes of brain and the more progressive ventricular enlargement by the combination of kaolin induced hydrocephalus and skull defect. As with above results, PVI values showed increasing tendency according to the degree of ventricular enlargement and the defect of skull.

An Experimental Study on the Cerebral Diaschisis in Acute Cerebral Infarction

To demonstrate the effect of diaschisis and to evaluate its possible mechanism in acute unilateral infarction, the changes of regional cerebral flows(rCBF's) on the both MCA territories and both cerebellum were measured by the hydrogen clearance method using the unilateral cerebral and cerebellar infarction model. Cerebral infarction model was made by left middle cerebral artery(MCA) occlusion through the transorbital approach and cerebellar infarction was made by coagulation of cerebellar vessels through retromastoid craniectomy. Experimental groups consisted of left MCA occlusion group-12cats, left MCA occlusion with callosal section group-15cats and cerebellar infarction group-13cats. After measurement of rCBF for 8 hours at fixed intervals the animals were sacrificed and immediately thereafter 50ml of 2% triphenyl tetrazolium chloride(TTC) solution was immediately injected in order to examine the size of infarction. The results were as follows ; 1) After occlusion of left MCA, the rCBF of ipsilateral MCA territory decreased abruptly and significantly(p0.05). 3) In the group of cerebellar infarction, the rCBF of contralateral cerebellum and both MCA territories did not decrease significantly in either group of cerebellar blood flow less than 10ml/ 100g/min or 10~20ml/ 100g/min. 4) In the experimental group of left MCA occlusion, infarction revealed 40.2+/-2.8% of coronal plane through the optic chiasm showing high percentage of infarction yield with small standard deviation. In the cerebellar infarction model the extent of infarction was 36.0+/-10.0% of horizontal planes of cerebellum in the group of rCBF below 10ml/100g/min. In the group of rCBF of 10~20ml/100g/min the extent of infarction was 22.0 +/-12.0%. These findings show the crossed cerebellar as well as interhemispheric diaschisis and support the importance of neural pathway in the mechanism of diaschisis. However further studies for long-term results and mechanism of diaschisis are needed.

Thoracic Spinal Stenosis

A stenotic spinal canal in the cervical or lumbar region is a well-known clinical entity. However, stenosis involving a thoracic vertebra is rarely mentioned in the literature. Improved neuroimaging facilities, especially MRI, let us detect the thoracic canal stenosis not so infrequently as in the past years. The authors are reporting six operative cases of thoracic myelopathy associated with thoracic spinal stenosis. Motor & sensory abnormalities were found in all cases during the clinical course. Magnetic resonance imaging and Metrizamide CT scanning were useful in the diagnosis of thoracic spinal stenosis. Treatment consited of wide posterior decompression resulting in symptomatic improvement in five of six patients.

An Experimental Study on the Effect of Measurement Parameters and Hydrocephalus on the Pressure Volume Index

To study the effect of measurement parameters and hydrocephalus on the pressure volume index(PVI), PVI study was performed in 5 normal and 5 kaolin-induced hydrocephalic cats. The effects of injection volume, speed, laterality and influence of increased intracranial pressure(ICP) in normal and hydrocephalic cats on the PVI value were evaluated. The results were as follows; 1) Larger injection volume, increased ICP by continuous infusion, and presence of ventriculomegaly made the PVI value significantly higher(p<0.01, p<0.001, p<0.05, respectively). 2) Rapid injection made the PVI value significantly lower(p<0.01). 3) Increase of ICP accentuated the effects of injection volume and speed significantly(p<0.01). 4) There was no difference between the PVI values measured with injection into the ipsilateral lateral ventricle and those measured with injection into the cantralateral lateral ventricle. 5) With the above results, it is considered advisable to perform the PVI study with constant injection volume, speed and ICP.

Clinical Analysis of Intracranial Aneurysms(Sep. 1957-Jun. 1988)

In order to have the statistical basis of intracranial aneurysms, the authors analyzed the cases of angiographically proven intracranial aneurysms which were admitted to the department of neurosurgery, Seoul National University Hospital from Sep. 1957 to June 1988. The results of analysis were summarized as follows; 1) Total number of patients was 564 and 64 patients had multiple aneurysms, so total number of aneurysms was 647. Peak age incidence was in the 5th & 6th decades and male to female ratio was 1 : 1.2. 2) Location of aneurysms were anterior communicating artery(32%), posterior communicating artery(28.1%), middle cerebral artery(21.5%) in the order of frequency. Posterior circulation aneurysms comprised 7.1% and multiple aneurysms were 11.3%. 3) Among 647 aneurysms, 368 aneurysms were neck-clipped(56.9%), and operative mortality was 4.9%. 4) After 1983, 300 patients of 344 aneurysms were admitted to the neurosurgical department. The size of aneurysm was most frequent in 6-10 mm in diameter(49.4%) and 5 giant aneurysms were detected. 5) Among 344 aneurysms, 253 aneurysms were neck-clipped(73.5%) and operative mortality were lowered to 2.4%. 6) Among 300 patients 287 patients had ruptured aneurysm. Angiographic spasm was detected in 32.1% and symptomatic spasm was in 19.5%. 7) Hydrocephalus was detected in 36.2% during the period of admission and follow-up. 8) Anterior communicating artery aneurysms ruptured most frequently among the multiple aneurysms. 9) Clinical state on admission was an important factor for the outcome and preoperative clinical state was related to the operative outcome and mortality.

Experimental exencephaly and myeloschisis in rats

To elucidate the early sequential morphogenetic progress of exencephaly and myeloschisis, rat embryos whose mothers had been treated with hypervitaminosis A were studied at 1-day interval from gestation day 10.5 to 15.5. In exposed animals sequential change was found in both exencephaly and myeloschisis as the embryos grew up. The 10.5-day old exencephalic embryos had still widely open cephalic neural tubes. Exencephalic embryos older than 13.5 days of gestation showed strikingly severe eversion and overgrowth of the cephalic neuroepithelium, thus failed in forming normal primitive brain. The convex dorsal surface of the exencephaly was covered with ependyma, which was connected directly with surrounding surface eqithelium at the periphery. The earliest morphologically recognized myeloschisis was in the 13.5-day old embryos. In myeloschisis, divergence at the roof plate and eversion of the spinal neural tube, disorganized overgrowth of the neuroepithelium, malformed and misplaced spinal ganglia and nerve roots, and absence of the neural arch and dermal covering were characteristic. It is suggested that exencephaly results from failure of the cephalic neural tube closure which is followed by eversion and overgrowth of the neuroepithelium. And failure in closure of the posterior neuropore and disturbance in the development of the tail bud probably play major role in the morphogenesis of myeloschisis.

Transsphenoidal Microsurgery of Pituitary Adenoma

Anthor reviewed the 102 cases of pituitary adnomas treated via transsphenoidal adenomectomy from August 1977 to July 1987, at the Seoul National University Hospital. The results obtained were as follows: 1) Male to female ratio of pituitary adenoma treated by TSA was 1:1.6. 2) Seventy-five cases(74%) of pituitary adenomas were functioning(endocrine-active) adenomas and twenty-seven cases(26%) were nonfunctioning endocrine-inactive). Functioning adenomas were composed of prolactin-secreting adenoma(47%), GH-secreting adenoma(25%) and ACTH-secrting adenoma(6%). 3) According to radiologic classification, intrapituitary adenoma(Grade I) was 4%, intrasellar adenoma(Grade II) 54%, diffuse adenoma(Grade III) 30% & invasive adenoma(Grade IV) 12%. 4) There was a significant relationship between prolactin value and size of prolactin-secreting adenoma, but no significant relationship was found between h-GH value and size of GH-secreting adenoma. 5) In prolactin-secreting adenoma, microsurgical removal of the tumor followed by bromocriptine administration was the most effective treatment modality. 6) In GH-secrting adenoma, decrease of fasting h-GH value was obtained more effectively in cases who under went surgery plus radiation therapy than in cases with surgery alone. 7) In prolactin-secreting adenoma and GH-secreting adenoma, there was no relationship between degree of decrease in hormone values after TSA and size of the adenoma. 8) Improvement in isual acuity and visual field defect after TSA was obtained in 32% of all pituitary adenomas. There was no operative mortality and complications after TSA were accompanied in 40% of all cases, majority of which were a transient diabetes insipidus.

Medulloblastoma:An Analysis of Factors Influencing on Its Prognosis

Authors analyzed the results of treatment in 49 cases of medulloblastoma who had been operated upon at the Seoul National University Hospital from January 1972 to June 1987. There were 2 cases(4%) of postoperative mortality(death within postoperative one month) and 13 cases of late moratlity. The 3-year overall survival rate was 49.3% and 3-year disease-free survival rate was 48.5%. The risk period of recurrence was about 2 years after surgery. The 3-year survival rate was significantly better in "grow total resection" group, "radiation dose more than 50 Gy" group, and group II(23 cases operated after July 1982) (p<0.05). The rate of posterior fossa recurrence was lower in "gross total resection" group for the patients who received posterior fossa irradiation of more than 50 Gy.

Neurosurgical Management of Cerebral Cysticercosis

Cerebral cysticercosis presents a quite variable clinical picture in its manifestation and course. This clinical polymorphism produces principal difficulties in its diagnosis and in planning therapeutic strategies as well as in evaluating therapeutic results. The author reviewed his experience with 52 cases of cerebral cysticercosis, surgically treated from 1977 to 1987 in Department of Neurosurgery, Seoul National University Hospital. The age of patients at time of diagnosis varied between 7 and 66 years(mean 43.4 years), with 75% from the fourth to the seventh decade. There was a 1.6:1 male to female ratio. The two most common residency of the patients, next to the Seoul area, were Cheju Provience(21%) and Chollanam Province(15%). The chief symptoms and signs were those of increased ICP(94%), focal neurological deficits(69%), seizure(40%), mental change(33%) and meningismus(21%). We classified 52 cases into the following groups based on the location of lesion in the brain CT scans:a) Parenchymatous(34%), b) Intraventricular(25%), c) Meningocisternal(18%), and d) Mixed type(33%). ELISA was highly reliable in making the diagnosis, this test, however, should not be regarded as a quantitative clue to evaluate the degree of curability. In cases no improvenent was achived clinically after praziquantel therapy and/or surgical treatment disappeared cysts in follow-up brain CT, a further diagnostic work-up to search for a intraventricular or mixed type is recommended. In 2 cases with a single, superficially located parenchymatous cyst, one burr hole trephination followed by aspiration using a brain needle was proved to be very effective. Surgical treatment in combination with a praziquantel therapy produced a marked improvement in 47 cases(90.4%) out of 52 cases. In the mixed type, the surgical outcome was unfavorable compared with other types.

An Experimental Study on the Changes of Regional Cerebral Blood Flow and the Effect of Calcium Antagonist in Acute Subarachnoid Hemorrhage

The present study was performed to elucidate the changes of regional cerebral blood flow(rCBF) and the effect of nifedipine, a calcium antagonist, on rCBF in acute subarachnoid hemorrhage(SAH) in cats. Another Purpose of this study was to document the effective dose and route of administration of nifedipine for maintaining rCBF in acute SAH. Subarachnoid hemorrhage was induced by intrathecal injection of autologous blood in 12 cats and rCBF was measured on the territories of both PCA, MCA, ACA, every 30 minutes for three hours using hydrogen clearance method. Sham operation was done in 5 cats. To study the effectiveness of nifedipine, nifedipine was administered after the induction of SAH in three different methods in 20 cats:intravenous injection in the amount of 0.1mg/kg in 7 cats, intravenous injection in the amount of 0.5mg/kg in 7 cats, and intrathecal adminstration of 10(-3)M, 1 ml, in 6 cats. The results were as follows; 1) Cerebral blood flows before the subarachnoid hemorrhage were 40.3+/-4.4ml/min/100g, 41.9+/-9.4ml/min/100g, 39.0+/-5.7ml/min/100g on the territories of right PCA, MCA, ACA and 41.5+/-7.4ml/min/100g, 42.5+/-9.6ml/min/100g, 41.3+/-9.9ml/min/100g on the territories of left PCA, MCA, ACA respectively. There was no significant difference between the territories. 2) After the subarachnoid hemorrhage, the cerebral blood flow was reduced immediately by 23.4-35.8% of control values and remained low for 3 hours in all six territories. 3) The rCBF in the group of intravenous injection of nifedipine in the amount of 0.1mg/kg was not significantly reduced immediately after SAH(p>0.05), but reduced after 3 hours(p0.01), but those in ACA territories were reduced to 60.4% and 61.7% of control values respectively. 6) Blood pressure was elevated from 135.4+/-20.2mmHg to 148.3+/-22.9mmHg at 30 minutes and then dropped to control level in SAH group. Groups of intrathecal administration of 10(-3)M and intravenous injection of 0.1mg/kg showed no significant change but group of intravenous injection of 0.5mg/kg showed significant drop of blood pressure. Intracranial pressure was elevated after SAH but returned to control value in 30 minutes. Intracranial pressure in the intrathecal injection group was markedly elevated and remained high for 3 hours. In conclusion, the rCBF was reduced immediately and remained low for 3 hours after SAH. Intravenous injection of nifedipine in the amount of 0.1ml/kg effective on increasing the reduced cereral blood flow. Intravenous injection of nifedipine in the concentration of 0.5mg/kg was less effective and showed significant hypotension. The effect of intrathecal administration of nifedipine was varied according to the location.

Surgical Management of Syringomyelia

Twelve patients were operated upon and diagnosed as syringomyelia at the Department of Neurosurgery of Seoul National University Hospital from July 1983 to June 1987. The etiologies were Chiari malformation(3 cases), arachnoiditis(2 cases), trauma(2 cases), neoplasm(2 cases) and idiopathic(3 cases). Four patients had foramen magnum decompression with 4th ventricle spinal subarachnoid space shunt and/or syringosubarachnoid shunt, and 7 patients underwent syringotomy or syringosubarachnoid shunt. In one case, only tumor removal was done. Functional improvement of the motor disturbance was noted only in 3 cases, in one of whom the result might be the effect of tumor removal. Pain and sensory disturbance responded well with surgery, but sphincter disturbance did not. The clinical, radiological and operative findings were correlated with theories of its pathogenesis. And the results of surgical treatment and some problems in the management of this disease entiry were discussed.

Spontaneous Intracranial Hemorrhage Caused by Brain Tumor

919 consecutive brain tumor cases and 665 consecutive spontaneous intracranial hemorrhage cases were reviewed for the analysis of cases in which spontaneous intracranial hemorrhage caused by brain tumor was confirmed with gross operative findings. Authors analyzed their incidence, patients' demography, tumor histology, clinical symptoms and signs, predisposing factor, tumor vascularity, type of hemorrhage, relations between the clinical symptoms and signs and the type of hemorrhage, relations between the location of tumor and the type of hemorrhage and the outcome of treatment. The conclusions are as follow; 1) The proportion of the hemorrhage caused by brain tumor to the total spontaneous intracranial hemorrhage was 5.1%(34/665). 2) The proportion of the spontaneous intracranial hemorrhage caused by brain tumor to the total brain tumor was 3.7%(34/919) and the proportion of that excluding pituitary adenoma was 2.5%(18/729). 3) Compared with the other brain tumors, oligodendroglioma and pituitary adenoma had significant tendency of hemorrhage(p<0.05, p<0.01, respectively) and meningioma had a significantly low incidence of hemorrhage(p<0.05). 4) The hemorrhage brought about major symptoms in 13 cases(72%), minor symptoms in 2 cases(11%). These cases showed no symptoms related to the hemorrhage. 5) Among the 18 cases of spontaneous intracranial hemorrhage caused by brain tumor, one case with the major attack died of postoperative pneumonia. There were additional 2 motalities which were not related to the preoperative hemorrhage. And most of the symptoms associated with the preoperative hemorrhage stabilized or improved with operative treatment.

A Case of Pleomorphic Xanthoastrocytoma

The pleomorphic xanthoastrocytoma has been known as a very rare type of glioma, which occurs mainly in the temporal lobe of the brain in young ages. It has distinctive characteristics regarding age, symptoms and signs, gross and microscopic features and relatively favorable prognosis despite of pleomorphism and bizarre giant cells in microscopic picture. The authors report a case of plemorphic xanthoastrocytoma presented with generalized seizure and review the past literatures.

Microsurgical Approach to Cerebellopontine Angle Tumors

The authors reviewed one hundred and twenty cases of cerebellopontine angle(CPA) tumors that were operated upon at the department of neurosurgery of Seoul National University Hospital between 1977 and 1987. The pathologic diagnosis of the tumors were acoustic neurinoma(66%), meningioma(13%), epidermoid(5%) and trigeminal neurinoma(5%). The age incidence was most frequent in the 5th and the 6th decades and 6.7% of cases occurred at the pediatric ages. Acoustic neurinomas were frequent in the 5th decade and on admission more than half of patients were poor clinical grades with large tumors more than 3cm in diameter(78.5%). There was good correlation between the clinical grade and tumor size on admission. All of the acoustic tumors were operated through the suboccipital transmeatal approach and total removal was possible in 73% with 5% of motality rate. Facial nerve was preserved in 62% of total removal-cases and the size of tumor was the important factor for the total removal of tumor with preservation of facial nerve. Cerebellopontine angle meningioma comprised 13% of all CPA tumors and incidence of male to female ratio was 2:13. Operations were performed either through retromastoid suboccipital approach or combined supra-infratentorial approach. Total temoval was possible in 67% without mortality. Six trigeminal neurinomas were located:one in the middle fossa, one in the posterior fossa and the other four cases appearing as dumbbell shape. Total removal was possible in two cases and subtotal removal in four cases and the outcome was rather good in all cases. Pediatric CPA tumors were two each of medulloblastomas and ependymomas and one each of astrocytoma, primitive neuroectodermal tumor(PNET) and trigeminal neurinoma, Masson's hemagioendothelioma. Total removal was possible in four cases and the outcome was good in all cases.

Primary Third Ventricular Tumors

Intrathird ventricular tumors that mainly occupy the ventricle cavity without extending to the neighbouring structures are rare. These tumors are developed from the choroids plexus, tela, ependyma, subjacent neuroglia and embryonic cell rest. The authors experienced 11 cases of rare intrathird ventricular tumors during the past 10 years. During the same period, number of surgically proven brain tumors were 990 and intrathird ventricular tumors comprised 1.1%. These are two cases of choroids plexus papillomas, three craniopharyngiomas, two germ cell tumors, one meningioma, one glioependymal cyst, one ependymoma, one astrocytoma. Suprasellar craniopharyngiomas, thalamic gliomas, optic and hypothalamic gliomas were excluded. The age distribution was from 6 years old to 59 years old. The clinical manifestation was characteristic in that they usually had the sudden intermittent headache without specific localizing signs. Surgical approach to this area is by transcallosal or transcortical approach. Surgical total removal was quite feasible by either approach and outcome was rather favorable.

Primary Third Ventricular Tumors

Intrathird ventricular tumors that mainly occupy the ventricle cavity without extending to the neighbouring structures are rare. These tumors are developed from the choroids plexus, tela, ependyma, subjacent neuroglia and embryonic cell rest. The authors experienced 11 cases of rare intrathird ventricular tumors during the past 10 years. During the same period, number of surgically proven brain tumors were 990 and intrathird ventricular tumors comprised 1.1%. These are two cases of choroids plexus papillomas, three craniopharyngiomas, two germ cell tumors, one meningioma, one glioependymal cyst, one ependymoma, one astrocytoma. Suprasellar craniopharyngiomas, thalamic gliomas, optic and hypothalamic gliomas were excluded. The age distribution was from 6 years old to 59 years old. The clinical manifestation was characteristic in that they usually had the sudden intermittent headache without specific localizing signs. Surgical approach to this area is by transcallosal or transcortical approach. Surgical total removal was quite feasible by either approach and outcome was rather favorable.

Primary Malignant Lymphoma of the Brain

The authors have studied six patients with histologically proven primary malignant lymphoma of the brain which is still a rare primary brain tumor. The clinical, radiological and pathological findings with results of the treatment are presented. All cases showed a good response to radiation therapy. Therefore, the early diagnosis by computerized tomography scan followed by biopsy or excision is considered to be very important for the BEST results in the treatment. Related reports are discussed briefly.

Spinal Cord Tumors : An Analysis of 175 Cases(1973-1986)

The authors analyzed 175 cases of spinal cord tumor who had been operated upon at the Department of Neurosurgery of the Seoul National University Hospital from 1973 to 1986. The tumor was most common in the 5th decade of age(47 cases, 26.9%) and 24 cases(13.7%) were children. And the ratio of male to female was 1.2:1. The pathologic diagnosis was neurogenic tumor in 73 cases(41.7%), metastatic tumor in 29 cases(16.6%), glial tumor in 24 cases(13.7%), and meningeal tumor in 23 cases(13.1%) in the order of frequency, and the tumors of dysembryogenesis were only 2 cases(1.1%). The tumors were located most frequently in the thoracic area(79 cases, 45.1%) and I the intradural extramedullary space(79 cases, 45.1%). The most common initial presentation was pain(86 cases, 49.1%) and the mean duration of presentation was 20.6 months. On admission 70 cases(40.0%) were in the 'paraparesis stage'. The mean value of the CSF protein was 741mg%. The rate of positivity of the plain spinal radiologic study was 55.7% and the most common positive findings was the increased interpedicular distance(46 cases, 29.1%). the total or gross total removal was possible in 105 cases (60.0%). The surgical result within the postoperative one month was recovery in 52 cases(29.7%), improvement in 76 cases(43.4%), stationary state in 36 cases (20.6%), progression in 11 cases(6.3%). After 20.1 months of the mean follow-up duration in 109 cases(62.3%), the result was recovery in 69 cases(63.3%), improvement in 16 cases(14.7%), stationary state in 8 cases(7.3%), progression in 16 cases(14.7%). As a major complication, there was a spinal deformity in 6 cases(3.4%), pulmonary embolism in 2 cases(1.1%), postoperative hematoma and meningitis in 1 case(0.6%) each. Ten cases(5.7%) were followed up to their deaths. And the authors discussed the clinical features of the spinal cord tumors reported in the literatures and the results of the present study with a more detailed consideration on each of major pathologies, neurogenic tumors, meningeal tumors, glial tumors, and metastatic tumors.

Surgical Treatment of Intracranial Aneurysms That Rebled During the Induction of Anesthesia

Authors discuss on the operative treatment of intracranial aneurysms that rebled during the induction of anesthesia before the main surgical procedures. The preoperative state of the patients had been quite stable. The bleeding manifested itself by risk fluctuations in vital signs, e.g., arrhythmia and blood pressure changes. The operation became extremely difficult, requiring various maneuvers to make room for the clipping of the aneurysms and experienced surgical techniques. Postoperative morbidity was apparently increased, through the patients could recover well with painstaking efforts. Diagnosis and management of such an event will be discussed with a brief review of the literature.

Occpital Lobe Arteriovenous Malformation

There were 13 cases of occipital lobe arteriovenous malformation(AVM) in a series of 100 intracranial arteriovenous malformations from Jan. 1981 to May 1987. Occipital lobe AVM's which encompass medial occipital, parieto-occipital, temporo-occipital AVM have distinct clinical and anatomic features. They usually present with bleeding, often accompanied by homonymous visual field deficit or with migrainous headache and seizure is very infrequent. However 4 cases out of 13 cases of our series had the seizure. The malformations were supplied principally by branches of posterior cerebral artery(PCA) but middle cerebral artery(MCA), anterior cerebral artery(ACA) and middle meningeal artery(MMA) were also contributed to the supply in some cases. The goal of surgery is to remove the conglomerated mass without disturbing the visual field. On considering the surgical approach, preservation of the visual field should be always kept in mind. We also discuss the surgical approaches.