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.

Effective of Naloxone on Cerebral Blood Flow in the Acute Stage of Experimentally Induced Subarachnoid Hemorrhage in Cat

The immediate fall in cerebral blood flow(CBF) and the early clinical picture following subarachnoid hemorrhage(SAH) correlate well with the prognosis of most of the patients. But the cause of this fall in CBF is not fully understood. Recently attention has been focused on the role of endogenous opiates in the pathogenesis of cerebral ischemia. This research was planned to observe the acute change of regional cerebral blood flow(CBF) in experimentally induced SAH, to investigate whether endogenous opiate plays a role in the mechanism of the acute reduction in CBF following SAH, and to document the therapeutic value of naloxone. We have studied the effects of naloxone, an opiate antagonist, on CBF, cardiovascular system, intracranial pressure (ICP) and electroencephalography(EEG) in pentobarbital anesthetized cats. Twenty - five adult cats were divided into four groups as follows : control group (group I; 5 caes), naloxone-treated control group (group II; 5 cats), SAH group (group III; 7 cats) and naloxone-treated SAH group (group IV; 8cats). The measurement of CBF was done by hydrogen clearance methods, and carried out every 20 minutes from the beginning to 140 minutes following SAH. Naloxone(10 mg/kg) was intravenously administered to cats, three times : 40, 80 and 120 minutes following SAH. The results were as follows : 1) We have induced SAH in 18 cats, in which 15 cats showed the immediate reduction in CBF following SAH(incidence rate : 83%). 2) Significant elevations in the mean arterial blood pressure(MABP : 141+/-10.7 to 146+/-12.3 mmHg) and ICP(19+/-3.5 to 21+/-3.9mmHg) were observed immediately after SAH, followed by reduction respectively to the levels of baseline value within 40 minutes after SAH. Naloxone had no significant influence on the changes in MABP and ICP. 3) Baseline values of CBF in group I and II were 44.5+/-6.9 to 50.1+/-5.4 ml/100g/min, and were not changed by naloxone. 4) Induction of SAH resulted in a significant reduction of blood flow to 34.8+/-5.9 to 38.4+/-5.6ml/100g/min(p<0.05), and the reduced value was not significantly changed through the experiment. Reduction in CBF was usually greater on the side of the lesion. 5) In group IV, the initial administration of naloxone made the reduced CBF increase to about 46 ml/100g/min(p<0.05), and the increased CBF value was maintained by the additional injections of naloxone. 6) Cats subjected to SAH exhibited progressive loss of amplitude and decreased frequency in EFG, which were improved by the administration of naloxone. These data suggest that endogenous opiate, which may cause decrease of cerebral metabolic rate and vasoconstriction, can play an important role in the mechanism of the acute reduction in CBF following SAH. Naloxone may induce increase in CBF by reversing the effects of endogenous opiate and its direct cerebral vasodilator properties.

Results of Direct Intracranial Surgery and Classification for 135 Anterior Communicating Artery Aneurysms

During the 10-year period up to December 1984, 176 patients with anterior communicating aneurysn(ACOMA) among total 467 patients of intracranial aneurysms were admitted to this Catholic Medical Center. Of these, 135 cases of ACOMA were operated by direct intracranial procedures. To analyse the factors influencing the mortality involving in surgery of 135 patients with ACOMA, a classification of ACOMA was attempted. The origins and projections of aneurysms, anatomical variations were analysed with the aid of angiography, intraoperative findings and intraoperative photographs which permitted the establishment of a classification of ACOMA with their direction. Our classification of operated 135 cases of ACOMA are seven types : 32 anterior(23.7%), 30 anterior-rostral(22.2%), 42 antefior-caudal(31.1%), 3 posterior(2.2%), 18 posterior-rostral(13.4%), 4 posteriorcaudal(3.0%), caudal 6(4.4%), respectively. Most of ACOMA projecting anteriorly, anterio-rostrally were situated above or between the optic nerve, and the less frequent posterior-caudal and inferior aneurysms were in close proximity to hypothalamic branches of the anterior communicating artery and A2 segment. There was on overall operative mortality of 6%. The surgical morbidity and mortality were significantly higher in the posteriorly projecting group, garticulary in the posterior-caudal direction. In direct surgery of ACOMA, subpial resection of the gyrus rectus was effective for not only anteriorly, but also posteriorly directing aneurysms.

Pontine Hemorrhages and Prognosis

Pontine hematomas are very rare lesions that in the past found at postmortem examination rather than diagnosed from the clinical presentations. Computed tomography has particularly stimulated further neurosurgical interest in this relatively rare condition, making surgical evacuation possible in some cases. Four patients suffering from pontine hemorrhages, revealed by computed tomography, are discussed. The classification regard to the site, clinical features and outcomes of this lesion are discussed in an attempt to establish general criteria for adequate management. With regard to the site, three types of hemorrhage are to be considered the tegmentotectal(type I), the tegmentolateral(type II) and the tegmentobasilar(type III), 2 patients(type I II, treated conservatively) had a fair outcome, and 2 patients(one of type III, treated conservatively, and one of type I, by surgical evacuation) had a death. Surgical management for the pontine hemorrhages should be reserved for the type I(tegmontotectal) and type II(tegmentolateral), whenever the neurological conditions deteriorate progressively.

Somatosensory Evoked Potential Responses in Focal Brain Lesions

Cerebral somatosensory evoked potentials(SEPs) produced by stimulation of peripheral nerves provide a useful diagnostic index of conduction in somatosensory pathways to the cortex. Thus the integrity of both the dorsal column-medial lemniscus pathway and primary sensorimotor area has been considered an essential requirement to record a normal SEP. There are suggestions that SEPs contain several components arising from different neuronal sources, the early short latency potentials corresponding to the lemniscus-mediated responses and the late waves to the diffuse spino-thalamic projections. The present work analyses the influence on SEPs of focal brain lesions, using the computerized tomography in detecting and localizing brain lesions. Somatosensory evoked potentials were recorded in 20 patients with focal brain lesions recognized by computerized tomography. 1) Patients with primary sensorimotor area(PSMA) damages(group I) had a very abnormal of the early component(No, Po, Nl, Pl) in 100% on the lesion side. 2) Patients presented supratentorial lesions, sparing PSMA(group II), 87.5% showing abnormal SEPs in early components and characterized by increment of amplitude in late components. 3) Brainstem damage(group III) produced a distortion of the early components especially N11, N20msec in latency. 4) In incomplete spinal cord injuries, the SEPs is indeed signal of functional recovery, of posterior column, and incorrespondance with clinical improvement.

Total Excision of an Arterio-Venous Malformation of the Corpus Callosum: Case Report

The arteriovenous malformations(AVMs) of the corpus callosum are distinct anatomical and surgical entities. The AVMs of the corpus callosum are supplied by the pericallosal arteries if the malformations are located in the anterior and middle portion of the callosum and the AVMs of the splenium are usually fed by the pericallosal and posterior cerebral arteries. Radical excision of the callosal AVMs became successful with microsurgical techniques since a few years ago. The authors report a case of the callosal AVM, who had subarachnoid hemorrhage twice prior to this admission, and the studies with angiography and computed tomography revealed an AVM involing the middle portions of the corpus callosum. Radical excision of the AVM was accomplished by microsurgical techniques without neurologic sequela.

A Case of Microgliomatosis of the Brain

A rare case of microgliomatosis(reticulum cell sarcoma) of the brain is reported. The tumor was located in the left parietal lobe and the right cerebellar hemisphere and the vermis. V-P Shunt was performed and left parietal craniotomy was done for removal of tumor. The patient received radiation therapy and chemotherapy for brain tumor with a good result Histogenesis and therapy of the microgliomatosis are briefly discussed.

Successful Treatment of Infantile Cerebral Hemorrhage

It is established that intracranial hemorrhage is relatively common benign intracranial diseases in adult. This is very rare in children reports are limited to a few cases or to those cited in reviews of series of intracranial hemorrhage in adult group. We wish to report three cases of large intracranial hematoma in three infants. The diagnosis was greatly facilitated by the CT scan and the treatment did by the microsurgical methods.