The data here presented indicated that stimulation of the brain stem reticular formation is accompanied by vascular changes leading to increase of cortical temperature. From comparison with other factors whose influence on cerebral vessels is known, it seems likely that either increase in blood flow or vasodilation may occur. Such vascular responses generally, but not always, accompany arousal EEG patterns. The study of possible neurohumoral mechanisms responsible for such phenomena is complicated by many factors. My results indicate that acetylcholine rather than adrenergic compounds may be involved.

The microsurgical anatomy of the middle cerebral artery(MCA) was reviewed. Embryology, segments, major branches, perforating branches, anomalies of the MCA and the anatomy of the Sylvian fissure were summarized.
Embryology ; Middle Cerebral Artery*

The effect of the calcium antagonist nimodipine on the feline cerebral cortical blood flow in experimentally induced subarachnoid hemorrhage(SAH) was studied. Cerebral cortical blood flow was measured in the middle cerebral territory at specified intervals by the hydrogen clearance method. SAH was induced in 25 cats by a slow injection of fresh autogenous arterial blood into the cisterna magna. Twenty-five cats were divided into 5 groups of 5 cats each according to the timing of the cerebral cortical blood flow measurements after SAH ; immediate(Group la, lb), 24 hours(Group 2), 48 hours(Group 3) and 7 days (Group 4). Cerebral cortical blood flow dereased by 55.5%, 39.2%, 41.4%, and 38.3% from pre-SAH levels in each group respectively. During nimodipine infusion(1 microgram/kg/min) cerebral cortical flow increased by 89.0%, 51.8%, 87.5% and 24.5% from pre-nimodipine infusion levels in each group respectively. Mean arterial blood pressure(MABP) after cisternal blood injection increased by 6.5% from pre-SAH levles, and MABP during nimodipine infusion decreased by 15.4% from pre-Nimodipine infusion levels. The calcium antagonist nimodipine increased cerebral cortical blood flow significantly in experimentally induced SAH without considerable changes of MABP. Results are considered promising for trials in the treatment and prevention of cerebral by vasospasm following SAH.
Animals ; Calcium* ; Cats ; Cisterna Magna ; Hydrogen ; Nimodipine* ; Subarachnoid Hemorrhage*

Cavernous malformation(CM) is one of the most common intracranial vascular anomaly. CM have dynamic lesion behavior and various clinical spectrum. Hemorrhagic risk and neurological disability seem to be related to multiple factors, including lesion location, age, gender, state of the reproductive cycle, and previous hemorrhage. Selecting the best treatment modality, each clinical scenario requires the proposal of a distinct management approach aimed at weighing the treatment risk against the best estimate of the cumulative natural risk. Management strategies include expectant follow-up in patients with asymptomatic or inaccessible lesions and microsurgical excision of symptomatic and accessible lesions. Radiosurgery could be applied for the progressively symptomatic lesions in inoperable locations, but the mortality and morbidity due to recurrent hemorrhage during latency period and radiation injury should be concerned.
Follow-Up Studies ; Hemorrhage ; Humans ; Latency Period (Psychology) ; Mortality ; Natural History ; Radiation Injuries ; Radiosurgery ; Risk Management

The authors performed prospectively the transcranial Doppler monitoring of bilateral anterior and middle cerebral arteries in 15 patients with ruptured cerebral aneurysm. The entry criteria for the study were confined to the patients who were admitted within 3 days after bleeding and had clinical grades of I, II, or III. The mean frequency shifts of bilateral anterior and middle cerebral arteries were increased immediately after ictus and showed continous further elevation between the 3rd and 8th rupture days. After that, they normalized slowly. The increase of frequency shift preceded clinical ischemic symptoms and an early steep increase of frequency shift was correlated to a high chance for suffering delayed ischemic deficits. The thick clots in subarachnoid cisterns shown on CT scans taken within the third rupture day were correlated well to the severe increase of frequency shifts. The aggressive treatment was done on asymptomatic patients who showed relatively rapid increase of frequency shifts, and they had shown no or trasient mild ischemic symptoms.
Hemorrhage ; Humans ; Intracranial Aneurysm* ; Middle Cerebral Artery ; Prospective Studies ; Rupture ; Tomography, X-Ray Computed

Microsurgical clipping is a standard treatment modality of cerebral aneurysms. Despite the far advances in surgical technique and craft, aneurysm surgery is still challenge to neurosurgeons. It carries considerable risk of mortality and morbidity to the patient unless the surgeon keeps the basic principles and tactics for accurate placement of aneurysm clip. To attain the goal of complete isolation of aneurysm from the cerebral circulation with concurrent saving parent artery and critical perforators, safe exposure of aneurysm, proper clip selection and accurate placement of the clip should be necessary. From exposure of target aneurysm to the final clip application, the authors will describe notable considerations for the successful clipping of aneurysm based on their own experience and review of literature.
Aneurysm ; Arteries ; Humans ; Intracranial Aneurysm* ; Mortality ; Parents

A 27-year-old woman with a clavicular fracture and post-traumatic hydrocephalus developed a subclavicular pseudomeningocele which was successfully treated by lumboperitoneal shunt. A brief review of the neurosurgical literature on the management of pseudomeningocele is presented.
Adult ; Female ; Humans ; Hydrocephalus

The isolated dog brain was perfused for a period of 4 minutes with blood normal in all constituents, but pathologically low in oxygen in order to follow the metabolic response of the brain to anoxia. During anoxic perfusion, the brain appears to subsist on the free amino acids in the brain and on glucose taken up from the perfusion blood. Oxygen uptake is relatively constant increasing temporarily immediately after anoxia. The lactic acid formed within the brain during anoxia is not released in any quantity; instead it appears to be metabolized in the brain following the period of anoxia causing a lower than norma1 uptake of glucose. Brain ATP and GrP levels decrease significantly, but not markedly indicating that the brain's energy requirements are being partially met during anoxic perfusion.
Amino Acids/*metabolism ; Animals ; Anoxia/*metabolism ; Brain/*metabolism ; Dogs ; Electroencephalography ; Glucose/*metabolism ; Lactates/*metabolism ; Oxygen Consumption

The author analyzed 66 cases of intracranial arteriovenous malformations treated in the Department of Neurosurgery of Yonsei University Hospital from 1977 to 1985. The results are summarized as follows : 1) The ratio of male to female was 2:1 and 75.8% or 50 cases were distributed between the 2nd and 4th decade. 2) The common presenting symptoms were either seizure alone(14%) or various symptoms resulting from hemorrhage(75%). 3) Arteriovenous malformations were suggested in 93.3% and were diagnosed in about half of the cases with the brain CT scan. Enhanced tubular shadow was the most important finding and hyperdensity of the lesion on precontrast brain CT scan was the most common finding. 4) The most common site of involvement was the supratentorial subcortical region with 75.4%, followed by the supratentorial deep region with 14.8%, and the infratentorial and dural region with 4.8%. 5) When compared to small(< 2cm) and large(> 4cm) lesions, there was less chance of hemorrhage in medium sized lesion(> 2cm to < 4cm). When the subcortical and deep regions of the supratentorial lesion were compared, there was no difference in incidence of hemorrhage. 6) According to angiographic findings, 46.6% was grade I lesions. The anterior cerebral artery and the middle cerebral artery were most commonly involved. 7) After craniotomy, total resection was performed in 34 of 43 cases or 79.1%. Due to either size or location, 14.4% or 7 of 43 cases were inoperable. 8) Immediate postoperative neurological deficits were noted in 12.5% or 6 of 48 cases. Non-hemorrhagic patients showed postoperative deficits more frequently than hemorrhagic patient did. 9) Regardless of treatment modality, there was a significant increase in number of patients who could be classified as grade I at discharge. 10) Long-term follow-up was carried out on 19 craniotomy cases. Neurological improvement was noted in 63.2% of these 19 cases. Among this group, there was no cases of neurological deterioration.
Anterior Cerebral Artery ; Arteriovenous Malformations ; Brain ; Cerebral Hemorrhage ; Craniotomy ; Embolization, Therapeutic ; Female ; Follow-Up Studies ; Hemorrhage ; Humans ; Incidence ; Intracranial Arteriovenous Malformations* ; Male ; Middle Cerebral Artery ; Neurosurgery ; Seizures ; Tomography, X-Ray Computed

Only about 15% of intracranial aneurysms involve the posterior circulation and about 80% of distal basilar aneurysms have their origin at the level of or above the posterior clinoid process. Therefore, they are potentially approachable via the pterional or trans-sylvian route. This imply that most neurosurgeons will relatively rarely be required to perform this procedure. Especially basilar bifurcation aneurysms arising substantially below the level of the posterior clinoid process or projecting posteriorly could be successfully repaired via subtemporal approach. There are number of unique surgical problems that can be best attacked through a subtemporal approach, and for this reason it is important to have facility with its performance and a detailed understanding of its advantages and limitations. Surgical tactics and pitfalls of subtemporal approach will be described with a basis of experiences in Yonsei University and review of literatures.
Aneurysm ; Intracranial Aneurysm*