A comparison of the effects on neuronal Golgi morphology, assessed with electron microscopy, of cardiopulmonary bypass, low-flow bypass, and circulatory arrest during profound hypothermia.

Adult swine (n = 18) were studied to compare the effects on neuronal morphology of hypothermic circulatory arrest with hypothermic very-low-flow cardiopulmonary bypass. Animals were anesthetized with halothane and prepared in a standard manner for nonpulsatile cardiopulmonary bypass. Monitored variables included mean arterial pressure, arterial blood gases, the processed electroencephalogram, and subdural brain temperature. Bypass was initiated with pump flows of 100 ml.kg-1.min-1, and mean arterial pressure was kept above 50 mm Hg at all times. Animals were cooled to 18 degrees C, using a heat exchanger, and were randomly assigned to one of three groups. Group 1 animals were control animals who underwent 1 hour of hypothermic cardiopulmonary bypass. Group 2 animals underwent 1 hour of circulatory arrest. Group 3 animals underwent 1 hour of very-low-flow cardiopulmonary bypass (10% of normal). At the end of the 1 hour of hypothermic bypass, very-low-flow bypass, or arrest period, animals were rewarmed to 37 degrees C with normal bypass flows, and normothermic perfusion continued for 1 additional hour. Animals were then perfusion fixed with formalin and the brains were removed for electron microscopic analysis. Electron microscopic analysis was used to determine the effects of treatment and was limited to 20 neurons of the CA1 sector of the hippocampus in each animal. Golgi bodies were identified and classified as normal, mildly affected, or severely affected. Animals subjected to either very-low-flow bypass or circulatory arrest had significantly more severely affected and significantly fewer normal Golgi bodies than control animals (p < 0.001). Animals maintained with very-low-flow bypass, however, had significantly more severely affected and fewer normal Golgi bodies than animals subjected to circulatory arrest (p < 0.001). We conclude that under the conditions of this experiment very-low-flow hypothermic cardiopulmonary bypass is associated with significantly greater neuronal Golgi abnormalities than total circulatory arrest.

Hormonal changes following hypophysectomy in humans.

PIP: Pituitary function was studied before and after surgery in 1 patient who underwent chryohypophysectomy and 5 patients who underwent transsphenoidal excision hypophysectomy for metastatic breast cancer ablation therapy. Changes in serum luteinizing hormone, follicle stimulating hormone, growth hormone, thyrotropin stimulating hormone, pituitary prolactin (PRL), and steroid hormone levels of estrone, estradiol, testosterone, and rostenedione, and dehydroepiandrosterone levels were determined. All of the above were assessed before and from 6 weeks to 10 months after hypophysectomy. Pituitary hormone release in response to sequential stimuli of arginine infusion, thyrotropic releasing factor (TRF), and luteinizing hormone-releaseing factor was analyzed. In 3 patients, hypophysectomy was considered incomplete because of the presence of measurable amounts of circulating pituitary hormones and their release in response to stimuli, although all levels except PRL were markedly reduced. In 3 patients, hypophysectomy was considered nearly complete. Basal PRL levels remained unchanged whether the procedure was considered complete or not. PRL release was absent in response to TRF or arginine stimulation in 4 patients with substantial residual pituitary function. Hypophysectomy was followed by a marked reduction in circulating levels of estrogens and androgens. The assessment of quantitative release of pituitary hormones in response to stimuli is an improved direct measure of residual functioning pituitary tissue.^ieng

Iotrol, a new myelographic agent: 2. Comparative electroencephalographic evaluation by spectrum analysis.

Iotrol, a nonionic dimer isotonic with cerebrospinal fluid at 300 mg l/ml, was evaluated against metrizamide, iopamidol, and iohexol by electroencephalography (EEG) in nonanesthetized cynomolgus monkeys. Each of four monkeys was injected intrathecally with 0.5 ml/kg of 300 mg l/ml of each contrast medium. EEG was obtained before, 45 min, and 3 hr postinjection. EEG spikes, motor disturbances, convulsions, and behavior changes were observed. The EEG from C3 channel was also computer-analyzed. Average percentage differences between control and test energy content of the entire EEG and of the EEG spectrum subdivided into five frequency bands were calculated. With metrizamide, three animals suffered seizures, and all were lethargic and irritable. With iopamidol, two animals convulsed; all animals were lethargic. Transient apathy and motor disturbances were observed in the iohexol animals. No motor or behavior changes were produced by iotrol. Metrizamide and iopamidol increased the spectrum energy in all bands. Neither iohexol nor iotrol affected the EEG significantly. On the basis of these findings, iotrol holds promise as a clinical contrast material for the subarachnoid space.

Mechanisms of whole blood-induced cerebral arterial contraction.

Using rabbit cerebral arteries in an in vitro chamber, we examined the cerebral arterial contraction initiated by clotting whole blood. By using methysergide maleate and a novel thromboxane synthetase inhibitor, 1-carboxyheptylimidazole (1-CHI), we studied the contributions of both serotonin and the prostaglandin metabolite thromboxane A2. Nontreated platelet-rich plasma (PRP) in the presence of methysergide produced a reliable contraction, whereas platelet-poor plasma did not. PRP from a rabbit pretreated with 1-CHI (50 mg/kg) compared to nontreated PRP caused a significantly smaller contraction. Blockade of this cerebral arterial contraction occurred without the disruption of platelet aggregation. Whole blood (1 ml) plus thrombin produced a consistent contraction over the 1 hour that was monitored. Whole blood drawn from a rabbit pretreated with 1-CHI (50 mg/kg) produced a smaller contraction, which began to dissipate in 5 minutes. When nontreated whole blood was added to the chamber in the presence of methysergide maleate (1.3 X 10(-5) g/ml), a contraction less than control was produced, and it persisted at 30 minutes. When whole blood pretreated with 1-CHI (50 mg/kg) was added to the chamber containing methysergide, there was a transient contraction that dissipated to nearly zero at 30 minutes. From our results, it is apparent that the thromboxane synthetase inhibitor has a profound effect on the later phase of blood-induced vasoconstriction. In contrast, the serotonin antagonist affected primarily the initial vasoconstriction and left the later phase largely unaltered. The role of thrombin, used to initiate coagulation, was also examined, and it was found to have a minimal direct constrictive effect when in a plasma solution.

Modification of experimental post-subarachnoid hemorrhage vasculopathy with intracisternal plasmin.

Utilizing a double subarachnoid blood injection model in pigs, we have evaluated the protective effect of the intracisternal injection of the thrombolytic agent, plasmin, in preventing the secondary intracranial arteriopathy seen after artificial subarachnoid hemorrhage in untreated animals. Twelve animals injected with plasmin revealed markedly less intimal proliferation and medial necrosis than were seen in control animals. These observations support the hypothesis that the persistence of clotted blood around the intracranial arteries is the cause of the vasculopathy.

Intranasal schwannoma with extension into the intracranial compartment: case report.

The authors present a case of intranasal schwannoma with extension into the intracranial compartment. Computed tomographic findings are presented, and a combined intranasal and subfrontal operative approach is described. The pathology, origin, and clinical characteristics of intranasal schwannomas are reviewed.

Modification of experimental post-subarachnoid hemorrhage vasculopathy with intracisternal plasmin.

This study using pigs was designed to determine the efficacy of delayed subarachnoid plasmin injection in preventing the vasculopathy secondary to experimental subarachnoid hemorrhage. Animals received cisterna magna injections of either plasmin or saline 2, 4, or 6 days after double subarachnoid blood injection. The cerebral blood vessels of all animals were examined histologically for evidence of intimal proliferation and medial necrosis. Angiography was not done. The results indicate a progressive increase in the extent and severity of intimal proliferation the longer plasmin injection is delayed. In contrast, the severity of medial necrosis did not correlate with the delay. We conclude that subarachnoid clot lysis is an effective way to prevent vascular injury from subarachnoid blood and that, the sooner it is done after hemorrhage, the more effective it will be.

Diagnosis and treatment of an odontoid fracture in a patient with polyostotic fibrous dysplasia: case report.

Fibrous dysplasia of the cervical spine is rare. No prior reports have discussed odontoid fractures in the setting of fibrous dysplasia. We describe a 26-year-old man who suffered a traumatic odontoid fracture in an area of preexisting fibrous dysplasia. The patient was treated conservatively in a sterno-occipito-mandibular immobilizer brace with a good result. A review of fibrous dysplasia is presented. Alternative methods of diagnosis and treatment options in our patient are discussed.

Intraoperative assessment of aneurysm clip placement by intravenous fluorescein angiography.

Clip occlusion of intracranial aneurysms can be difficult, and intraoperative misadventures are still fairly frequent. Many complications are caused by improper clip placement. Intraoperative conventional arteriography is time consuming and requires expensive image-intensifying equipment. As an alternative, we have found that the bolus intravenous administration of fluorescein produces the necessary intra-arterial dye concentration for the direct visualization of the perforating medium and large arteries in proximity to a clipped aneurysm. The technique is straightforward, requiring little additional operating time and an inexpensive set of disposable optical filters. No adverse reactions to fluorescein have been observed.

Needle biopsy under computerized tomographic control: a method for tissue diagnosis in intracranial lesions.

Thirteen patients with intracranial lesions were submitted to a twist drill needle biopsy under computerized tomographic (CT) control, with sedation and local anesthesia. (The patients' ages ranged from 12 to 81 years.) The final diagnoses were glioblastoma in 7 patients and 1 case each of anaplastic astrocytoma, low grade astrocytoma, thrombosed arteriovenous malformation, cerebral infarct, 3rd ventricular epidermoid, and degenerative disease of the brain. Definitive diagnosis was obtained in all but 2 patients with this technique. Appropriate therapy was subsequently instituted in 11 patients without further operation. Transiently increased weakness of the previously affected limbs was the only untoward effect (4 patients). Intracranial hematoma after this procedure was seen in 1 patient in this series, as detected by the postprocedure CT scan, but there was no change in the clinical course. All patients were treated with dexamethasone for 24 to 48 hours before and for several days after the procedure to avoid decompensation of intracranial dynamics because of edema. The procedure, including appropriate level CT scans of the lesion area, was performed in approximately 1 hour in all patients. (Neurosurgery, 5: 671--674, 1979).

Demonstration by magnetic resonance of symptomatic spinal epidural lipomatosis.

In patients with Cushing's syndrome or morbid obesity, excessive accumulation of fat in the hips, upper back, abdomen, and mediastinum is well known (1, 3, 7). Excessive deposition of fat in the epidural space is less common, but must be recognized as a potential cause of neurological deficit (1-8). We report a patient with iatrogenic Cushing's syndrome, in whom magnetic resonance imaging (MRI) established the specific diagnosis of spinal cord compression secondary to excess epidural fat.

Pilocytic astrocytoma presenting as an extra-axial tumor in the cerebellopontine angle: case report.

Glial tumors in the cerebellopontine angle (CPA) are rare. Four histologically distinct types of glial tumors of the CPA have been described in the literature as ependymoma, medulloblastoma, mixed glial tumor, and fibrillary astrocytoma. This case report describes a pilocytic astrocytoma of the CPA. A 58-year-old man with a hearing loss had an extra-axial tumor in the left CPA that extended into the internal auditory canal. The characteristics of the tumor on magnetic resonance imaging scans differed from those of typical CPA tumors. It adhered avidly to the cochlear and vestibular nerves, which had to be sacrificed for gross total resection. Microscopic examination showed the typical features of an adult-type pilocytic astrocytoma.

Stereotaxic occlusion of 22 consecutive anterior communicating artery aneurysms.

The authors review 22 consecutive cases of anterior communicating artery aneurysms treated by stereotaxic iron-acrylic occlusion. There was no mortality and no rebleeding in this series. The morbidity was low, and 16 of the 22 patients have returned to work. The patients whose aneurysmss could be treated transsphenoidally enjoyed the best outcome.

Retromastoid cisternal Ommaya reservoir for intrathecal therapy of coccidioidomycosis meningitis. Technical note.

A method is described that simplifies placement of an Ommaya reservoir for chronic access to the basilar cisterns. This technique is useful in treating coccidioidomycosis and other fungal meningitides.

Iron-acrylic compound for steriotaxic aneurysm thrombosis.

A new iron-acrylic compound has been developed for stereotaxic thrombosis of intracranial aneurysms. The compound polymerizes rapidly, does not fragment, and is nontoxic. It has been used in a series of experimental animals and in initial clinical cases with good results. The use of this material simplifies and increases the safety of stereotaxic aneurysm treatment.

Stereotaxic thrombosis of inaccessible intracranial aneurysms.

Some intracranial aneurysms that might be considered inoperable by open craniotomy are readily treatable by stereotaxic thrombosis. This is possible because the stereotaxic technique requires only that some point on the fundus of the aneurysm can be punctured with a needle. Illustrative cases are given describing the successful treatment of aneurysms arising at the origin of the ophthalmic artery, within the cavernous sinus, within the sella turcica, and from the vertebrobasilar and the posterior inferior cerebellar arteries ventral to the brain stem. The aneurysms within the sella or cavernous sinus can be approached through the sphenoid sinus, and the aneurysms ventral to the brain stem can be approached through the clivus without opening the dura.

Infections complicating the use of external ventriculostomy.

The use of external ventriculostomy at our institution has been retrospectively analyzed to determine the incidence of cerebrospinal fluid sepsis. Placement of 65 ventriculostomies over a 2-year period resulted in three cases of complicating meningitis and ventriculitis (4.5%). Duration of ventriculostomy placement did not seem related to the rate of infection but the method of placement, the prophylactic antibiotics used, and the monitoring and collecting system employed may be important.

Success of microvascular decompression with and without prior surgical therapy for trigeminal neuralgia.

Clinical records and patient interviews in 37 cases of trigeminal neuralgia treated by microvascular decompression by a single surgeon were studied retrospectively. Outcomes were determined with an average follow-up period of 43 months. Abnormalities in the region of the trigeminal nerve were identified in each case. Patients undergoing microvascular decompression as a primary procedure were cured (total pain relief without further therapy) at a rate of 91%, versus 43% in patients treated with destructive procedures (rhizotomies) prior to microvascular decompression (p less than 0.005). Analysis also suggests that trigeminal neuralgia of greater than 9 years' duration was cured at a rate of only 42%, versus 88% in cases of less lengthy duration (p less than 0.005). Sex and age at time of surgery were not significant predictors of outcome. There were no deaths in this group of patients aged from 32 to 90 years. A horizontal surgical approach is described.

Intimal proliferation of cerebral arteries after subarachnoid blood injection in pigs.

A model of experimental subarachnoid hemorrhage in young pigs has been created using two subarachnoid blood injections. Cerebral arteries of the pig demonstrate intimal proliferation and medial necrosis 10 days after experimental blood injection; this appears to be a reaction to arterial injury. The similarity between the arterial reaction to subarachnoid blood and the general process of atherosclerosis is noted, and steps have been taken to insure that the vasculopathy described is truly a response to the injected blood. The authors conclude that the intimal proliferation observed between 1 and 2 weeks after experimental subarachnoid blood injection is an indicator of arterial injury and is, therefore, a good end point for further studies.

Pathogenesis of cerebral vasospasm.

Cerebral arteries have been shown to react to experimental subarachnoid hemorrhage with a nonspecific arterial injury reaction characterized by endothelial cell desquamation, adherence of platelets to the exposed collagen, subendothelial edema, and medial necrosis. This injury reaction is followed by a reparative process with intimal proliferation and medial fibrosis. We have postulated that the arterial narrowing seen by angiography in patients after subarachnoid hemorrhage may be a manifestation of this injury reaction. Because it is likely that the platelets adherent to the damaged endothelium play a major role in the propagation of the process, it is possible that therapy directed at preventing platelet accumulation may interrupt the cycle.