Neurogenic factors for the tonus of the cerebral blood vessels were investigated by systemic administration of phentolamine (PH) and norepinephrine (NE) in lightly anesthetized and immobilized dogs. Systemic blood pressure (SBP), intracranial pressure (ICP), and cerebral blood flow (CBF) were recorded simultaneously. Reversible blocking of the brain function was produced by a local injection of 4% lidocaine hydrochloride. Elevation of ICP to a certain value was produced by continuous intracisternal infusion of saline. In the control experiment, administration of PH produced a decrease in SBP as well as in CBF, and a rise in ICP. Administration of NE produced bi-phasic rises in SBP, and a temporary rise followed by a decrease in ICP, and increase in CBF. This pattern of changes became more marked at a raised ICP level of 30-40 mmHg. Blocking of the hypothalamus did not change the pattern of SBP and ICP fluctuations after administration of drugs, compared with the control experiment. However, in animals with blocking of the midbrain, pons, and medulla, ICP showed a simultaneous change with SBP after administration of drugs, and 0.2-0.3 ml lidocaine hydrochloride injection into each region was necessary to make these simultaneous changes in SBP and ICP. It is suggested that the tonus of the cerebral blood vessels is controlled by the broad areas of brain stem.
Experimental cerebral infarction was induced in 94 dogs by injecting one or two silicone rubber cylinders through the cervical internal carotid artery. The 47 large-sized infarctions of the cerebral hemisphere (LSICH) were more frequently created with a double silicone embolization (DSE; 76.2%) than with a single silicone embolization (42.5%). In the DSE method, the first embolization gave rise to an occlusion of the proximal segment of the middle cerebral artery. The lenticulostriate arteries were also occluded directly. With the second embolization, a point occlusion of the orifice of the posterior communicating and/or anterior cerebral arteries occurred, but the perforators from these arteries were not occluded directly. Therefore, the LSICH model showed widespread infarction, involving the basal ganglia, the cortex, and the white matter in the territory of the middle cerebral artery. The massive hemorrhagic area in this LSICH model tended to be localized in the basal ganglia (10.4%). Similarly, red softening was localized in the corticomedullary junctional area (89.6%) and pale softening, in the boundary zone between the middle and posterior cerebral arteries (39.6%), respectively. From histopathological examination, it was also suggested that the massive hemorrhagic area might be caused by disruption of arterioles in the perforating arterial terminal zone. By contrast, the red softening area was due to disruption of the venules in the cortical arterial terminal zone. Pathogenetic mechanisms of the location of three types of infarction in LSICH model are also discussed.
Regional cerebral blood flow (rCBF) was measured in 25 patients with transient ischemic attacks (TIA) and 34 patients with reversible ischemic neurological deficits (RIND) or ischemic strokes with full recovery. The rCBF measurements were performed by means of the 133Xe intracarotid injection method, using a scintillation camera and an on-line computer system. The rCBF data were analysed and compared with the computed tomography (CT) and angiographic findings on each patient. There was no significant difference in the average of the mean hemispheric values of rCBF (mean CBF) between TIA and RIND. The averages of mean CBF of TIA or RIND were significantly lower than those of the normal controls, and higher than those of the completed strokes. There was no correlation between the elapsed time from the last attack and the mean CBF in TIA. There was also no correlation between the elapsed time from the onset, or between the presence or absence of hemiparesis and the mean CBF in RIND. CT showed lacunae in 24% of TIA and 32% of RIND, whereas a cortical low density area was shown in only one case in each group. Angiographic abnormalities were found predominantly in the intracranial major arteries, rather than the extracranial carotid artery in both groups. Six patients of TIA (24%) and 6 of RIND (18%) had involvement of their extracranial internal carotid artery. There was no correlation between the mean CBF and angiographic findings. Although the mean CBF did not correlate to CT findings in TIA, it was significantly lower in RIND patients with lacunae on CT scans. Hemispheric pattern of flow distribution (HPFD) was disturbed in 88% of TIA and 74% of RIND. Focal ischemia was shown in only one case with RIND, whereas diffuse ischemia was shown in 2 cases with TIA and 5 cases with RIND. Loss of the hyperfrontal pattern which was thought to represent a mild diffuse cerebral dysfunction, was shown in 44% of TIA and 29% of RIND. Because diffuse involvement of HPFD was shown without reference for the elapsed time from the last attack of TIA or the onset of RIND, the authors support the ‘hemodynamic’ theory as opposed to ‘microembolic’ theory as the cause of TIA or RIND. It is concluded that TIA and RIND have the same causative factors, and the clinical difference of TIA and RIND is the only difference in recovery times between TIA and RIND.
Intraarterial digital subtraction angiography (DSA) was applied 259 times to 203 neurosurgical patients. In cases with cerebral occlusive diseases, the circulatory dynamics could be recognized more accurately by DSA, which showed not only the location and the distance of the occlusive vessels, but also the collateral circulation. By the results of the DSA, the choice of operative treatment, that is, endarterectomy or the construction of bypass with interposed graft, could be planned preoperatively. The stereoscopic DSA, with the images subtracted by the arterial or capillary phase, could demonstrate more obviously the anatomical locations of the cerebral arteriovenous malformations and normal vasculatures. Also, the tumor blushes and the sinuses are more detectable in DSA than in the conventional angiography. The intraarterial DSA is thought to be helpful for the choice of the neurosurgical operations.
Occlusion of the common carotid artery (CCA) has been found in patients with atherosclerosis or aortitis syndrome. Surgical treatment is indicated, if the patient has symptomatic cerebral ischemia. In the present report, 7 cases of occlusion of the CCA is described and surgical treatment is discussed briefly. Three cases among them were treated surgically; i.e. two cases by subclavian artery to internal carotid artery vein graft and one by thyrocervical artery to CCA anastomosis. All cases showed clinical improvement postoperatively. Reconstructive surgery in the neck is more effective than extracranial - intracranial bypass surgery, e.g. superficial temporal artery - middle cerebral artery anastomosis in the treatment of the occlusion of CCA.
Operative specimens of 73 pituitary adenoma cases (25 cases of prolactinoma, 24 cases of acromegaly, 21 cases of non-functioning adenoma, and 3 cases of gonadotropin secreting adenoma) were examined immunohistochemically for luteinizing hormone (LH) β subunit, follicle stimulating hormone (FSH) α subunit, FSH β subunit, and thyroid stimulating hormone (TSH) by using the peroxidase antiperoxidase method. Four cases of prolactinoma were positive for the FSH a subunit. Nineteen cases of acromegaly were positive for the FSH α subunit. These cases were also positive for the FSH β and/or LH β subunit. In gonadotropin secreting adenoma all 3 were positive for both FSH α and β subunits. Eleven cases of non-functioning adenoma were positive for the FSH α subunit. Six of 11 (3 male and 3 female) were positive only for FSH α subunit. A high serum human chorionic gonadotropin a subunit value was recognized in 1 case of these 6. In an endocrinological study of non-functioning adenoma cases of positive FSH a subunit low response of TSH to TSH-releasing hormone loading and low response of LH to LH-releasing hormone (LH-RH) loading were found. However, this abnormal response was not statistically significant. In FSH response to LH-RH loading 1 case had delayed response and 7 cases had low response. This abnormal FSH response to LH-RH was statistically significant in 9 FSH α subunit positive cases. These data indicate that there are a subunit secreting pituitary adenomas in the group which has been diagnosed as “non-functioning adenoma”.
The authors report a case of thoracic herniated disc, and review clinical symptoms, diagnostic methods and operative procedures. A 45-year-old male patient was admitted because of numbness, paraparesis of both lower extremities, bilateral hyperactive patellar and achilles tendon reflexes, and sensory impairment below the level of Th10 dermatome. Myelography and metrizamide computed tomography (CT) myelography revealed a Th7/8 soft disc herniation and a Th8/9 calcified disc protrusion. He underwent surgery through the lateral approach. A left hemilaminectomy from Th7 to Th9 and costotransversectomy of the left Th8 and Th9 were performed. The Th7/8 and Th8/9 herniated discs were completely removed by microsurgical procedure. The postoperative course was uneventful and the postoperative CT scan demonstrated complete removal of the herniated discs and full decompression of the spinal cord. He developed no neurological deficit during a 3-month postoperative follow-up.
Of intracranial hemorrhage cases in the neonatal period, acute subdural hematomas in the posterior fossa caused by birth trauma are much less frequent than those located above the tentorium. Those located in the posterior fossa often show rapid deterioration and death. Six cases of this type of hematoma have been experienced in the last ten years. In all of these cases, onset occurred within seven days after birth, and five of them were difficult breech presentation cases and were delivered by such methods as forceps extraction. An overall neurological and computerized tomography (CT) scan examination indicated that the cases with good outcome showed signs and symptoms from 72 hours after delivery. Signs of intracranial hypertension were usually present in these cases, but signs of brain stem dysfunction were usually absent. In CT scans, localized high density areas were seen on the upper or lower surface of the cerebellar hemispheres. Fatal cases had an Apgar score of 5 points or less after delivery, and the symptoms occurred from immediately after, to six hours after delivery. The main symptoms in these cases were signs of brain stem dysfunction, such as respiratory disturbance and opisthotonus. In CT scans, there were high density areas in the basal cisterns around the brain stem, in the fourth ventricle, and in the vermis. As for the long term results, acute hydrocephalus affected the outcome of the posterior fossa hematomas in the neonate. CT scans generally provided useful information with respect to both diagnostic and therapeutic results. However, it is difficult to decide from the information of CT scans where the source or point of the bleeding is located. Because this disease occurs in a period when vital resistance is at its lowest, rapid and accurate diagnosis and adequate treatment are necessary. Therefore, a detailed investigation of neurological symptoms and repeated CT scans after abnormal delivery are essential.
Cerebral angiography of a 34-year-old male case of subarachnoid hemorrhage revealed a right posterior communicating artery aneurysm, associated with fibromuscular dysplasia (FMD) of the bilateral vertebral and occipital arteries. Because of a tendency of the level of consciousness to decrease, an intentionally delayed operation was performed on the 14th day after onset. The postoperative course was good and the patient was discharged with no neurological deficiency. Twenty cases of cervico-cephalic FMD in the Japanese literature was reviewed, including 9 cases associated with cerebral aneurysm(s), and the features were compared with cases in the international literature. Higher incidence was observed in females and generally onset presented symptoms of ruptured aneurysm or cerebral ischemic attack with approximately equal frequency. FMD of the internal carotid artery had aneurysm(s) in the anterior half of Willis's ring, whereas FMD of the vertebral artery had aneurysm(s) in the posterior half of the ring. These findings suggest a possible relationship between the location of the cervico-cephalic FMD and that of intracranial aneurysm.
The capsule of a retrocerebellar glio-ependymal cyst, which was incidentally found in a 54-year-old asymptomatic female, was studied by both light and electron microscopy. Microscopically, the capsule measured 25-400 μm in thickness and consisted of four layers. The external covering was an arachnoid cell layer abutting on the thick connective tissue with scattered vessels, whereas the luminal lining was a layer of ependymal cells abutting on the glial tissue. The ependymal cells were cuboidal in shape and some, but not all, were ciliated. The glial tissue underneath the ependymal lining contained numerous corpora amylacea, especially in its abluminal side. Electronmicroscopically, the arachnoid cell layer consisted of both arachnoid epithelium and the underlying arachnoid cells. The former showed a relatively higher electron density than the latter. There was a distinct basement membrane between them. In the former, a moderate number of desmosomes and intermediate junctions assured contacts between the arachnoid cells. In the latter, there were many extracellular clefts containing numerous collagen fibrils and microfibrils. Neighboring cytoplasmic processes often formed interdigitations. The luminal surface of ependymal cells displayed variable numbers of microvilli with or without cilia, whereas the abluminal surface abutted directly on the astrocytic processes of the glial layer. There were some interdigitations of the plasmalemma of adjacent cells, with surface specializations consisting of fasciae adherentes joined by gap junctions. Two or more adjacent cells contributed to the development of microrosettes, packed with both numerous surface microvilli and several profiles of cilia. The corpora amylacea varied 5-15 μm in diameter and consisted of randomly oriented filaments with fine osmiophilic granules. The fibrillar elements within the processes of the fibrillary astrocytes swept around the corpora amylacea or impinged upon the latter. Although their outline was usually smooth and clearly demarcated, no membrane or space intervened between the corpora amylacea and the surrounding structures. It is most probable that the present glio-ependymal cyst arose from the displaced segment of the wall of the neural tube, which corresponds to the sites from which the tela chorioidea forms.
A case of multiple intracranial epidermoids is reported. A 38-year-old woman who had a three-year history of hemihypesthesia on the right side of her body, diplopia, gait disturbance, dysarthria, and visual field defect, was admitted. Neurological examination revealed right hemiparesis, bilateral abducens palsies, and cerebellar dysfunction. A computed tomography (CT) scan demonstrated a huge low density area in the left middle cranial fossa and heterogeneous density area in the brain stem. She was diagnosed tentatively as epidermoid in the middle fossa and intraaxial mass of the brain stem. Surgery was performed twice. In the first operation, the temporal mass was removed subtotally. Secondarily, only suboccipital craniectomy was performed. After the second operation, her condition deteriorated due to recurrent aseptic meningitis and aspiration pneumonia. She died three months later. Autopsy revealed that an epidermoid was situated in the brain stem intraaxially and another epidermoid was located in the temporal region independently. An intraaxial epidermoid is a rare entity, especially in the brain stem. There is no report of multiple intracranial epidermoids in the literature. The authors emphasize the necessity to rule out epidermoid, when CT shows a high or heterogeneous density area, even if multiple and/or contrast enhanced.
A case of hemorrhage from hemangioblastoma is reported. A 52-year-old female was admitted with an episode of sudden-onset consciousness disturbance and double vision. Six years previously she had been treated by a ventriculo-peritoneal shunt, radiation therapy and partial removal of a cerebellar hemangioblastoma. Computed tomography showed a massive hemorrhage around the recurrent tumor in the left cerebellar hemisphere and a ventricular bleeding. Evacuation of the hematoma was immediately performed. The tumor could be removed only partially because it bled easily. Postoperative left vertebral and carotid angiography disclosed that the tumor was mainly supplied by the left superior cerebellar and the tentorial arteries. In the second operation, the left superior cerebellar artery was clipped temporarily through the subtemporal approach, and the tumor was extirpated totally through the suboccipital approach. Histological examination confirmed hemangioblastoma. Mechanism of the massive hemorrhage from hemangioblastoma is discussed.