The purpose of this study was to evaluate the constrictive effect of endothelin, a peptide vasoconstrictor derived from endothelium, on canine basilar artery. Constriction was measured by an isometric tension recording method. Endothelin induced prolonged contraction of canine basilar artery in a dosedependent fashion, the estimated concentration at 50% contraction being (2.1 ± 0.5) × 10-9 M (mean ± SEM). Removal of endothelium significantly augmented the arterial response to endothelin. In Ca++-free medium no contractile response was elicited at 10-8 M endothelin. Papaverine (10-4M) and nicardipine (10-8 M), a calcium channel blocker, almost completely inhibited the contraction induced by 10-8 M endothelin. Pretreatment with nicardipine (10-8-10-6 M) also significantly suppressed the response to endothelin. Acetylcholine (10-7-10-4M), adenosine triphosphate (10-7-10-5M), and thrombin (0.1 and 1.0 U/ml) dose-dependently inhibited contraction of canine basilar artery in response to 3 × 10-9M endothelin. These results show that endothelin has a potent constrictive effect on canine basilar artery and suggest that this substance may play an important role in the pathogenesis of vasospasm following subarachnoid hemorrhage.
The direct current (DC) potential and electroencephalographic (EEG) changes were continuously monitored following fluid percussion head injury (brain contusion) in 10 conscious rats. Local cerebral glucose utilization (LCGU) was measured by the autoradiographic [14C]deoxyglucose method. Measurement of LCGU was started at the lowest point of the first or second DC potential negative shift when it occurred, and 2 hours after contusion if no DC potential changes were observed. The DC potential did not change in four rats (Group A), whereas DC potential negative shifts together with marked suppression of EEG activity occurred at 54 ± 6.9 minutes after injury in six rats (Group B). In Group A, LCGU was decreased nonsignificantly in both the right and left cortices. In Group B, however, LCGU in the lesioned cortex rose to 160-190% of the level observed in the contralateral cortex (p < 0.05). The autoradiographic pattern in Group B was identical to that seen in spreading depression. These findings can contribute to the effort to better understand the pathophysiology of head injury.
The teratogenicity of ethylenethiourea (ETU) was investigated in Sprague-Dawley rats and Landrace pigs. Pregnant rats each received a single intragastric dose of ETU on a given day from day 8 to day 19 of gestation, and pregnant pigs were given a single dose of ETU from day 15 to day 19. Control animals received an ETU-free vehicle. The newborn pigs were all normal, whereas there were high incidences of specific types of congenital malformation of the central nervous and other systems in the rats. A high incidence of lumbosacral myeloschisis associated with hindbrain crowding was observed in rat fetuses exposed to ETU on day 11 of gestation. This abnormality is considered comparable to Chiari type II malformation associated with spinal dysraphism (Arnold-Chiari malformation) in humans. Morphogenetic fetuses were examined by light and scanning electron microscopy and interactive image analysis. At gestational days 12 and 13, the volume of the caudal end of the neural tube from the anterior border of the hindlimb bud to the most caudal portion of the fetus was significantly greater in ETU-exposed than in control rat embryos. Experimental rat embryos also exhibited disturbance in closure of the posterior neuropore, with extrusion of neural tissue through the opening. An apparently unrelated abnormality in ETU-exposed rat fetuses was underdevelopment of the cranium, leading to hindbrain crowding. The results of this study suggest that hindbrain crowding and lumbosacral myeloschisis in the rat are two separate phenomena, each of which occurs independently in response to an insult to the entire developing organism. Lumbosacral myeloschisis is caused by nervous tissue overgrowth that interferes with closure of the posterior neuropore, and hindbrain crowding is due to the growth of normal brain tissue in a too-small cranial cavity.
The prognosis of fetal hydrocephalus is poor and the results of intrauterine decompression have so far been unsatisfactory. Although several factors have been known to affect the prognosis of intrauterine hydrocephalus, few histological studies of preterm hydrocephalus and no immunohistochemical analyses have been reported to date. In eight fetal cases of untreated preterm hydrocephalus, the authors morphologically studied neuronal maturation by means of immunohistochemical and specific myelin staining techniques. The patients' gestational ages at death ranged from 20 to 40 weeks (mean, 30 weeks). There were two cases of simple form of hydrocephalus, two of cerebral dysgenesis (hydranencephaly and holoprosencephaly), and four of hydrocephalus secondary to intraventricular hemorrhage. Relatively primitive neuronal developmental processes, such as neuronal cell proliferation and migration, were found to be altered by rapidly progressive simple form of intrauterine hydrocephalus, whereas the neuronal maturation disorder was obviously the primary condition in dysgenetic hydrocephalus. Hydrocephalus itself, however, caused additional damage in the presence of delayed but slowly progressing neuronal development. Secondary hydrocephalus initially reflects impairment of previously normal neuronal maturation. In this situation, too, hydrocephalus per se further compromised the potential for continued neuronal development. The results of this study imply that the pathoembryological concepts of fetal hydrocephalus are not so simple. Early decompression may preserve the potential for further neuronal maturation in fetal hydrocephalus.
The authors measured alkaline phosphatase isozyme I (ALP-I) in sera of 24 brain-damaged patients and four with disorders other than brain damage. The study population comprised three patients with postresuscitation encephalopathy, four with ruptured cerebral aneurysms, 14 with acute subdural hematoma and cerebral contusion, and three with nontraumatic intracerebral hemorrhage. ALP-I detected in brain damage is physicochemically different from the other known ALP-Is that appear in patients with obstructive jaundice or hepatoma. In the brain-damaged patients, ALP-I became elevated about 7 days after admission and markedly increased as secondary brain damage developed. Excluding patients who died within 9 days of admission, the maximum serum ALP-I concentration was well correlated with the functional outcome. In cases in which barbiturate therapy was effective, the appearance of ALP-I was delayed and its elevation was suppressed. The results of this study suggest that measurement of serum ALP-I is useful not only in the management but also in predicting the prognosis of brain damage.
The author measured blood concentrations of aldosterone, epinephrine, norepinephrine, and creatine kinase isozyme (brain type)(CK-BB) in 65 patients with hypertensive intracerebral hemorrhage. The purpose of this study was to evaluate these measurements in determining the severity of acute cerebral damage in such patients. There were 42 males and 23 females ranging in age from 30 to 93 years. Their clinical status was classified as mild or severe on the basis of neurological grading. In the mild group, plasma aldosterone increased slightly at the onset of disease, while the other markers showed no change. In contrast, the severe group showed elevation of all markers on admission, with a gradual return to normal by day 3 to day 7 of hospitalization. Analysis of the data by hematoma site revealed that aldosterone levels increased in patients with thalamic hemorrhage; epinephrine and norepinephrine concentrations were high in those with pontine hemorrhage; and CK-BB levels were elevated in cases of thalamic and cerebellar hemorrhage. It was also noted that patients in whom all four markers were increased tended to have poor outcomes.
The authors describe the clinical and radiological features, surgical procedures, and outcome of 18 cases of clivus meningiomas and six of apicopetroclivus meningiomas. There were 17 females and seven males, ranging in age from 26 to 69 years, with a mean age of 47 years. All except one showed cranial nerve deficits. Computed tomography accurately demonstrated tumor size and location. Cerebral angiography showed characteristic displacement of the basilar artery and its tributaries, with blood supply to the tumor largely via the meningohypophyseal trunk. Magnetic resonance imaging was excellent in delineating the relationship of the tumor to the brainstem and major vasculature. The surgical approaches used were transpetrosal-transtentorial (n = 9), combined transpetrosal-transtentorial-transzygomatic preauricular transpetrosal (n = 9), suboccipital-subtemporal (n = 2), suboccipital (n = 1), frontotemporal (first stage operation) followed by suboccipital (second stage operation) (n = 1), suboccipital-transpetrosal (n = 1), and orbitozygomatic-infratemporal preauricular transpetrosal (n = 1). Seventeen tumors were totally removed and seven subtotally. The operative mortality was 8% (two patients). Twenty patients developed new cranial nerve deficits within 1 month of surgery. The average follow-up period was 5 years, and the outcome was good or excellent in 12 cases. Transpetrosal approaches proved relatively safe and effective for radical tumor removal and, in two cases, permitted preservation of useful hearing. Early diagnosis, use of microsurgical techniques, and preoperative determination of the anatomical relationship of the tumors to the surrounding structures contributed to the favorable operative results.
Over a 16-year period, 105 patients with pituitary adenoma accompanied by visual disturbance underwent transcranial intracapsular removal of the tumor followed by radiotherapy. Postoperative recovery of visual function in these patients was compared with the results obtained in other institutions after trans-sphenoidal surgery. The severity of preoperative visual impairment was correlated with the duration of visual impairment, the degree of optic atrophy, the extent of suprasellar tumor infiltration, and age. Trans-sphenoidal surgery appears more effective in patients with mild preoperative visual disturbance, whereas the transcranial approach yields better results in patients with moderate to severe preoperative visual deficits.
A case of subependymoma of the septum pellucidum in a 54-year-old female is presented. Computed tomography and magnetic resonance imaging revealed a partially calcified mass with intratumoral hematomas, and cerebral angiograms disclosed a relatively hypovascular lesion. Preoperatively, a cavernous angioma was suspected. The tumor was removed, and histological examination proved it to be a subependymoma containing a fine fibrillary matrix. On immunohistochemical analysis, both the matrix and the tumor cells were positive for glial fibrillary acidic protein staining.
The authors describe a case of intracranial malignant teratoma in a 28-week fetus, discovered on assessment of the mother's excessive abdominal enlargement. Alpha-fetoprotein levels in amniotic fluid and serum were high. Ultrasonography revealed a large, solid intracranial mass. The fetus was viable until completion of a cesarean delivery, at which time the heart stopped. At autopsy, the fetal brain was found to have been extensively replaced by a solid, cystic tumor, which proved to be a malignant teratoma comprising elements of all three germ cell layers. The authors' experience and review of the reported cases indicate that prenatal malignant intracranial teratoma can be safely and accurately diagnosed, and that immediate delivery or cranial decompression may be advisable when the diagnosis is established. The usefulness and limitations of ultrasonography are particularly emphasized.
The authors describe a case of well differentiated (grade I) chondrosarcoma in a 52-year-old male. The tumor originated in the posteromedial wall of the left petrous bone and extended into the posterior fossa and cervical spine. He showed impaired functions of the left VII to XII cranial nerves. Plain skull x-rays demonstrated erosion of the left petrous and occipital bones, with speckled calcifications. Computed tomography showed a huge mass of slightly high density with mushroom-like calcifications, which was poorly enhanced by contrast medium. Inversion recovery magnetic resonance imaging clearly defined the low-intensity lesion, while the long spin-echo image depicted the tumor as mixed-intensity. On electron microscopic examination, the tumor cells were rich in Golgi apparatus, endoplasmic reticulum, glycogen granules and mitochondria in the cytoplasm, and formed many vacuoles crossing the cell membrane. These vacuoles were suggested to play an important role in matrix formation. Thirty nine other reported cases of chondrosarcoma are reviewed, and the two reported posterior fossa chondrosarcomas are compaired with that of ours.
A case of symptomatic Rathke's cleft cyst simulating an arachnoid cyst is presented. Although computed tomography and magnetic resonance imaging showed that the cyst content was identical to cerebrospinal fluid, there was faint contrast enhancement in part of the wall. Histological observation suggested that the somewhat vascular connective tissue associated with nests of pituitary cells might have contributed to the enhancement. This type of Rathke's cleft cyst requires further clinical and neuroradiological studies.
A 26-year-old primipara with a cerebral venous angioma suffered an intracerebral hemorrhage just after delivery. Venous thrombosis was considered a possible cause of the intracerebral hemorrhage on the basis of the neuroradiological findings.
The authors describe the case of a 19-day-old infant with a ruptured intracranial aneurysm. She had suddenly become lethargic after drinking milk. Cerebral angiography demonstrated a large aneurysm arising from the right middle cerebral artery. Because the aneurysm was fusiform, the parent artery was clipped. Histological examination of a specimen taken from the aneurysmal dome showed an organized thrombus with deposition of a calcium-like substance in the wall, which appeared on histochemical examination to be pseudolime. The postoperative course was uneventful and she was discharged without neurological deficits.