Melatonin concentration in human blood and cerebrospinal fluid: relationship to stress.

In 35 daytime paired blood and cerebrospinal fluid (CSF) samples from 15 patients, melatonin levels in CSF were undetectable or detectable but not higher than blood levels. During pneumoencephalography in 6 patients, no significant elevation of blood melatonin levels was observed, whereas cortisol concentration increased.

Expression of three viral oncogenes (v-sis, v-myc, v-fos) in primary human brain tumors of neuroectodermal origin.

We determined which viral oncogenes (v-sis, v-myc, and v-fos) were expressed in five primary human brain tumors of neuroectodermal origin (two glioblastomas multiforme, one medulloblastoma, one cystic cerebellar astrocytoma, and one ganglioglioma) and which of these oncogenes is correlated with malignancy. Using the dot hybridization technique, we determined the relative amounts of mRNA coded by these genes using the same nitrocellulose filter. The v-myc probe showed a 4- to 12-fold greater hybridization to the mRNA from two glioblastomas and the medulloblastoma (malignant group) than the mRNA from the cystic cerebellar astrocytoma or the ganglioglioma (benign group). In contrast, RNA hybridizing to v-sis and v-fos were accumulated to a greater extent in the benign tumors. These data suggest that the amount of myc expression may be correlated with the degree of malignancy of brain tumors of neuroectodermal origin.

Spinal nerve enhancement with Gd-DTPA: MR correlation with the postoperative lumbosacral spine.

PURPOSE: To search for a probable source of the recurrent signs and symptoms associated with lumbosacral postsurgical syndrome on intravenous gadolinium-enhanced MR. METHODS: A retrospective study of 120 patients with recurrent symptomatology following lumbar disk surgery was carried out with spin-echo MR pre- and postenhancement with gadopentetate dimeglumine (0.1 mmol/kg). In addition, 10 asymptomatic subjects were evaluated at least 6 months postoperatively using the same imaging protocol. RESULTS: 21.6% of the symptomatic subjects (N = 26) had enhancement of one or more spinal nerve root. This enhancement was focal or multisegmental, and involved single or multiple nerve roots. The abnormal neural enhancement was associated with otherwise isolated epidural fibrosis in 88.5%, and with herniated nucleus pulposus in the remaining 11.5%. The overall clinical correlation of single root enhancement with a monoradiculopathy and multiroot enhancement with a polyradiculopathy was 95.7%. However, 21.7% of these same cases also showed additional nerve root enhancement that did not have an overt clinical correlation. All of these latter patients were imaged relatively early in the postoperative period (5 days to 8 months). The 10 patients in the asymptomatic group all manifested degrees of postoperative epidural scarring on MR, but no abnormal radicular enhancement or other associated pathology. CONCLUSION: In the chronic postoperative phase (more than 6 to 8 months), the presence of radicular enhancement on MR imaging in symptomatic individuals, and its absence in asymptomatic subjects, suggests that neural enhancement serves as a marker for active neural pathology that may in certain individuals be related temporally to the signs and symptoms associated with the lumbosacral postsurgical syndrome.

Aneurysms of the persistent hypoglossal artery.

The primitive hypoglossal artery is one of four embryonic anastomoses between the carotid and basilar arterial systems. The so-called persistent hypoglossal artery is most likely a complex vessel comprised proximally of a persistent hypoglossal artery and distally of components of the primitive lateral basilar-vertebral anastomotic network. This is the sixth reported case of an aneurysm of the persistent hypoglossal artery, and it is unique in its association with two supratentorial aneuryms, one of which had ruptured. All three aneurysms were treated by a direct surgical approach (two operations). Review of the other published cases demonstrates that these aneurysms arise at the junction of the persistent hypoglossal with the basilar artery. Aneurysms of this vessel require direct surgical treatment, because the parent vessel is functionally the only artery supplying the brain stem and therefore may not be ligated. The aneurysms usually lie in the subarachnoid space, indenting the brain stem, and may be approached through a suboccipital craniectomy.

Multifocal cavernous hemangioma of the skull: report of a case and review of the literature.

Primary hemangiomas, which are rare skeletal tumors, represent 0.7% of all osseous neoplasms. They are most commonly found in the vertebral column. They are exceedingly rare in the calvarium, accounting for 0.2% of all bone neoplasms. Most calvarial lesions are unifocal, but multiple hemangiomas have been reported. We present the case history of a 64-year-old man who was admitted with frontal and occipital headaches. He was found to have two radiolucent lesions on plain x-ray, left frontal and left occipital, which proved to be cavernous hemangiomas. The gross appearance, histopathology, radiological findings, and treatment options are reviewed.

Cerebral revascularization: proximal external carotid to distal middle cerebral artery bypass with a synthetic tube graft.

A right proximal external carotid to distal middle cerebral artery bypass with a prosthetic tube graft was performed in a patient with intermittent cerebral ischemia due to middle cerebral artery stenosis. The patient was relieved of his symptoms, and he was neurologically normal 3 months after operation. Angiography 3 months postoperatively revealed flow through the graft and excellent filing of the middle cerebral circulation, both retrograde and antegrade. Early results suggest that an expanded polytetrafluoroethylene graft may be useful as a vascular conduit if suitable autogenous vessels are unavailable or have failed.

Cerebral revascularization: common carotid to distal middle cerebral artery bypass.

A right common carotid to distal middle cerebral artery bypass utilizing a saphenous vein graft was performed in a patient with episodic cerebral ischemia and reversible ischemic neurological deficit. The patient was relieved of his symptoms, and there was improved motor function in the left hand. Postoperative angiography revealed flow through the graft with excellent filling of the middle cerebral circulation, both retrograde and antegrade. This bypass procedure provided an immediate source of high volume blood flow and thereby provided immediate protection to the hemisphere.

Intermittent appearance of a ruptured cerebral aneurysm on sequential angiograms. Case report.

The change in size of a ruptured anterior cerebral artery aneurysm was recorded in a series of angiograms. The aneurysm did not appear on the initial angiogram, but was seen on the second study. Incomplete filling was seen on the third angiogram, and the aneurysm appeared to have thrombosed on the fourth angiogram. On the fifth angiogram, done 5 weeks after the first, the aneurysm filled completely. It was subsequently clipped.

Cranial epidermoid tumor associated with subacute extradural hematoma. Case report.

The authors present a case of cranial epidermoid tumor that caused a subacute epidural hematoma after minor trauma. The radiological, operative, and pathological findings are described, and indications for elective excision of cranial epidermoid tumor are discussed.

Subclavian steal syndrome. Part 1: Proximal vertebral to common carotid artery transposition in three patients, and historical review.

Three patients with central nervous system symptoms due to subclavian steal syndrome were treated with proximal vertebral to common carotid artery transposition. Neurological symptoms were relieved or improved in all three, with no decrease in blood pressure or pulse in the ipsilateral upper extremity. The colorful history of this syndrome is reviewed, and the various surgical approaches to its treatment are discussed. Although the literature suggests that the commonly used carotid to subclavian artery bypass graft and other similar extrathoracic procedures are generally safe and effective for relief of symptoms of the steal, there is also evidence that these bypasses may fail to restore antegrade flow in the vertebral artery, and, in fact, may steal from the carotid artery. Thus, the blood flow provided to the brain by these procedure may be hardly more than that provided by vertebral artery ligation, whereas the principal effect is to restore blood flow into the upper extremity. Vertebral artery ligation alone has been used in 20 patients, with neurological improvement in all cases and production of persistent intermittent brachial claudication in only one. These considerations and our patient experience suggest that a relatively simple operation, proximal vertebral to common carotid artery transposition, which emphasizes restoration of flow to the brain rather than to the upper extremity, may be preferable for most patients with neurological symptoms of subclavian steal syndrome.

Subclavian steal syndrome. Part 2: Intraoperative vertebral artery blood flow measurement.

Intraoperative vertebral artery blood flow was measured in two patients with symptomatic subclavian steal syndrome, before and after proximal end-to-side vertebral to common carotid artery transposition. This confirmed retrograde flow in the vertebral artery before transposition, and antegrade flow after transposition. The measured flow rates were compared to values in other series involving different operative procedures for correction of symptomatic subclavian steal. The greatest mean antegrade flow rates in the vertebral artery were restored by proximal end-to-side vertebral to common carotid artery transposition.

Chronic measurement of epidural pressure with an induction-powered oscillator transducer.

An induction-powered oscillator transducer (IPOT) was designed for the chronic measurement of epidural pressure. The transducer was completely implantable so all pressure measurements were made through the intact skin. The IPOT had a linear pressure range from -50 to +200 cm H2O, was sensitive to 1 mm H2O and had a zero drift of less than 1 mm H2O/day under full load. Zero drift was minimized by using a hermetically-sealed metal bellows transducing element which was chemically treated to prevent corrosion and creep. The correlation between epidural pressure and intraventricular pressure was determined during the first 24 hours after implantation in six dogs. Epidural pressure was found to be a linear function of intraventricular fluid pressure. Epidural pressure and intraventricular pressure were essential equal provided the epidural wedge pressure was minimized by proper insertion of the transducer. The correlation between epidural pressure and intraventricular pressure was determined after chronic implantation in five dogs. Epidural pressure was a linear function of intraventricular pressure in the chronically implanted dogs, but epidural pressure was not equal to intraventricular pressure. After chronic implantation, the epidural pressure transducer was not responsive to changes in intraventricular pressure because of mechanical changes in the dura. The dura became stiff and non-compliant. Maximum correlation between epidural pressure and intraventricular fluid pressure in chronic implantations will depend on judicious material selection and mechanical design at the transducer-dura interface.

Polytetrafluoroethylene interposition grafts in vertebral to carotid artery transposition. A long-term follow-up study.

Eight patients undergoing an end-to-side vertebral artery (VA) to common carotid artery transposition between August, 1979, and July, 1982, had a polytetrafluoroethylene (PTFE) interposition graft placed when a direct anastomosis was believed not to be satisfactory. Five of these patients are living; clinical and radiographic follow-up studies over periods ranging between 54 and 82 months show that their transpositions are patent. Two patients died perioperatively, one from an acute anterior myocardial infarction and the other from acute VA occlusion with a propagating thrombus. A third patient died of myocardial infarction 20 months after graft placement; the anastomosis had been found patent at 12 months. This report gives the clinical and radiographic follow-up results in a previously reported group of patients with PTFE interposition grafts. Some of these patients have been followed for over 6 years after surgery: the average radiographic follow-up period in the five survivors is 60 months, and all grafts are patent without evidence of progressive stenosis. Expanded PTFE appears to be an acceptable material for short interposition grafts in operations involving the VA; however, direct artery-to-artery anastomosis is preferred. The results of longer PTFE grafts in reconstructive cerebrovascular surgery have not been adequately studied.

Proto-oncogene analyses in brain tumors.

The present study determined which oncogenes (N-myc, c-myc, v-sis, or v-fos) were amplified and which messenger ribonucleic acids (mRNA's) accumulated in 10 primary human brain tumors of neuroectodermal origin. The tumors included four glioblastomas multiforme, one mixed glioma (astrocytoma grade I and ependymoma), one astrocytoma grade II, one cystic cerebellar astrocytoma, one ependymoma, one ganglioglioma, and one medulloblastoma. The relative amounts of polyadenylated (poly(A)+) RNA's homologous to these genes and their copy number were determined using the RNA and deoxyribonucleic acid blot hybridization techniques. The N-myc and v-sis probes hybridized strongly to the poly(A)+ RNA from the same recurrent glioblastoma with gene amplifications (N-myc 80 copies; v-sis three to four copies). The c-myc probe hybridized strongly to the recurrent medulloblastoma without gene amplification. The amplification or abundant accumulation of mRNA's homologous to their oncogenes may be involved in tumorigenesis or the aggressiveness of these malignant brain tumors of neuroectodermal origin and may be good molecular indicators of an extremely malignant state in these tumors.

Cauda equina syndrome of long-standing ankylosing spondylitis. Case report and review of the literature.

Cauda equina syndrome as a neurological complication of long-standing ankylosing spondylitis was first reported in 1961. The syndrome is relatively uncommon and its pathophysiology is still poorly understood. Based on their experience with such a case, the authors review the clinical, electrographic, histological, and radiographic features of the syndrome, including the findings of magnetic resonance (MR) imaging. The addition of MR imaging to the evaluation of patients with ankylosing spondylitis and the cauda equina syndrome not only aids in the diagnosis of the syndrome but may also provide valuable insight into the pathophysiology of this condition.

Villaret's syndrome: a report of two cases.

The syndrome resulting from lesions of the lower four cranial nerves (CN) and the cervical sympathetic chain is known as Villaret's syndrome. We report two cases of the syndrome and emphasize the localizing value of this constellation of signs. The second case is unusual because involvement of the cervical sympathetic chain produced sympathetic overactivity, instead of the usual sympathectomy effect. Increased sympathetic outflow expressed as pupillary dilation, widened palpebral fissure, and facial sweating (the Claude Bernard syndrome) usually occurs as an early manifestation of apical thoracic tumors and has not been previously associated with Villaret's syndrome.

Cerebral revascularization with an artificial graft: long-term follow-up and discussion of the role of graft pretreatment with modified host endothelial cells.

Controversy remains regarding the effectiveness of EC/IC bypass for the prevention of stroke and the authors believe that some studies suggest that a subcategory of patients disabled by transient flow-related symptoms may benefit from surgery. The authors present a 7 1/2 year follow-up analysis of a patient who had undergone an EC/IC bypass from the proximal extracranial carotid to the middle cerebral artery using a 4 mm Gore-Tex prosthesis. Following his death from pulmonary sepsis, the graft was retrieved. Pathological and electron microscopic findings are reviewed.

Extracranial surgical procedures in the management of vertebrobasilar insufficiency.

Vertebrobasilar insufficiency is an important syndrome in the spectrum of cerebrovascular disease. Its clinical importance and the frequency of its clinical manifestations are often underestimated. Our experience with a large population of patients having extensive cerebrovascular disease has led us to recognize two classes of vertebrobasilar insufficiency--simple and complex--and, also, to recognize that vertebrobasilar insufficiency is often associated with disease in multiple extracranial vessels. Until recently, direct approaches to the vertebral artery have been underutilized for these patients. In fact, there has been a tendency either to relegate patients with vertebrobasilar disease to medical follow-up or to surgical procedures upon the carotid system. We believe that the resurgence of neurosurgical interest in the vertebrobasilar system is most appropriate. Furthermore, the active interest that neurosurgeons are now taking in developing procedures for managing extracranial vertebral artery problems is in the best interest of patients with cerebrovascular disease. We believe that careful neurosurgical evaluation of patients with simple and complex vertebrobasilar insufficiency will lead to appropriate selection of candidates for vascular reconstruction of the vertebral system. Finally, we believe that vertebral artery to common carotid artery transposition, and its variations, is a procedure that has an important role in the management of cerebrovascular disease.