bluuebunny/crossref_metadata_2025 huggingface dataset:
Paradoxical cerebral air embolism without an intracardiac septal defect
Authors: Marquez Jose , Sladen Arnold , Gendell Howard , Boehnke Manfred , Mendelow Harvey
Published: May 2009

✓ Cerebral air embolism occurred in a patient undergoing trigeminal rhizotomy in the sitting position. During the acute episode, a murmur was detected by the Doppler probe and foam was aspirated from the central venous catheter. The patient did not regain consciousness postoperatively, and computerized tomography demonstrated diffuse cerebral infarction. Subsequently, the patient died, and neuropathological examination revealed multifocal discrete infarcts in the gray and white matter with normal intervening brain. No intracardiac septal defects were present. This is the first fully documented case of cerebral air embolism of venous origin in the absence of intracardiac septal defects, and reemphasizes the hazards of operative procedures in the sitting position.
Burr-hole ring-cap and electrode anchoring device
Authors: Ray Charles D.
Published: May 2009

✓ A new burr-hole ring and cap are described. The threaded ring is C-shaped, holding itself in the burr hole by elastic recoil. A ventricular catheter or deep brain electrode may be passed through the slotted ring and anchored in place by means of a mushroom-shaped silicone rubber cap. The cap fills, sealing the plug. This simple two-part device, originally designed for use with a deep brain stimulator system, may also be used as a standard ⅝-in. (16 mm) burr-hole plug.
Influence of the type of intracranial lesion on outcome from severe head injury
Authors: Gennarelli Thomas A. , Spielman Gerri M. , Langfitt Thomas W. , Gildenberg Philip L. , Harrington Timothy , Jane John A. , Marshall Lawrence F. , Miller J. Douglas , Pitts Lawrence H.
Published: May 2009

✓ Recent studies attempting to define the outcome from severe head injury have implied, directly or indirectly, that the severity of injury (as determined by the Glasgow Coma Scale (GSC)) is the sole determinant of outcome. Little attention has been focused on the type of lesion that causes the low GCS score, and there exists an unstated hypothesis that the lesion type is not an important determinant of outcome. No attempt has been made to determine whether patients who have the same GCS score caused by different lesions have the same or different outcomes. Since this is impossible to test without a large number of cases, data were obtained from seven head-injury centers on patients who fulfilled the Glasgow criteria for severe head injury (GCS ≤ 8 for at least 6 hours). Patients were categorized according to a simple classification system comprising seven lesion types, each of which was further subdivided into two GCS score ranges (3 to 5 and 6 to 8). Of 1107 patients, the overall mortality was 41%, but ranged from 9% to 74% among the different lesion categories. Conversely, 26% had good recovery (at 3 months), but among the different lesion groups the range was 6% to 68%. Acute subdural hematoma with GCS scores of 3 to 5 was uniformly the worst problem (74% mortality and 8% good recovery), whereas diffuse injury coma of 6 to 24 hours with GCS scores of 6 to 8 had 9% mortality and 68% incidence of good recovery. Results of this study demonstrate marked heterogeneity within this severe head-injury group and point out that patients with the same GCS score have markedly different outcomes, depending on the causative lesion. The type of lesion is thus as important a factor in determining outcome as is the GCS score, and both must be considered when describing severely head-injured patients.
Spontaneous resolution of occlusive lesions of the carotid artery
Authors: Kapp John P. , Smith Robert R.
Published: May 2009

✓ The authors review the literature concerning spontaneous resolution of occlusive lesions involving the carotid artery. They add four cases illustrating three pathological vascular processes that may resolve spontaneously, namely, arterial dissection, atheromatous lesions at the carotid bifurcation, and an arteriopathy involving the intracranial vessels which is poorly understood at this time.
Failure of intravascular volume expansion without hemodilution to elevate cortical blood flow in region of experimental focal ischemia
Authors: Wood James H. , Snyder Lauri L. , Simeone Frederick A.
Published: May 2009

✓ Cerebrovascular and cardiac alterations evoked by intravascular volume expansion with whole blood, a popular adjunct in the clinical prevention or therapy of the focal ischemic deficits of cerebral vasospasm and acute stroke, were studied in splenectomized dogs. Clipping of the right distal internal carotid and proximal middle cerebral arteries in eight dogs reduced regional cortical blood flow (rCoBF) by 49% to 58% without altering cardiac output (CO), and produced about 10% hemispheric infarction. Eight dogs underwent similar cerebral arterial occlusion and eight dogs underwent arterial manipulation without clipping. Both latter groups received two autologous whole blood infusions within 2 hours, each equal to 20% of the respective dog's total blood volume. Despite significant CO elevations after the infusions, rCoBF in the middle cerebral arterial territory did not rise. These whole-blood infusions did not significantly alter mean arterial blood pressure, hematocrit, intracranial pressure, or, in dogs with clipped cerebral arteries, the relative size of infarction.

These data suggest that nondilutional hypervolemia neither elevates collateral perfusion to ischemic regions of the brain nor reduces infarction. In addition, elevations in CO do not appear to augment blood flow in either ischemic or normal brain.
The effect of heparin reversal after carotid endarterectomy in the dog
Authors: Chandler William F. , Ercius Mark S. , Ford John W. , Burkel William E.
Published: May 2009

✓ The purpose of this study was to determine if total reversal of heparin immediately after carotid endarterectomy would have an adverse effect on the thrombogenicity of the endarterectomized vessel wall. After systemic heparinization, unilateral common carotid endarterectomies were performed under the operating microscope on 14 dogs. Half of the animals were given protamine sulfate to reverse the heparin. Three hours after resumption of blood flow, these arteries, as well as contralateral vessels used as controls for fixation technique, were perfused with glutaraldehyde and prepared for scanning electron microscopy (SEM). Thrombin clotting times were measured throughout the experiments. Sections of the endarterectomized portions viewed by SEM showed nearly total coverage of the exposed collagen of the media with flattened platelets. There were scattered leukocytes, but few erythrocytes, little fibrin, and no true thrombus. There were no differences between the animals that received heparin reversal and those that did not. A group of five additional arteries underwent the same procedure except that no heparin was given. As expected, large amount of thrombus had formed within the lumina of these control vessels by 3 hours. Since previous studies suggest that arterial thrombosis usually occurs within 3 hours of endothelial injury, the authors conclude that total reversal of heparin does not increase thrombogenicity of the endarterectomized vessel. This suggests that heparin may be safely reversed in patients to help maintain postoperative hemostasis.
Chiasmal apoplexy
Authors: Maitland Charles G. , Abiko Seisho , Hoyt William F. , Wilson Charles B. , Okamura Tomomi
Published: May 2009

✓ Four patients with chiasmal syndromes were found to have intrachiasmal hematomas. Computerized tomography scans showed high-density suprasellar masses in all cases. Cryptic vascular anomalies were presumed to be responsible for spontaneous bleeding into the chiasm in three of the cases. In the remaining case, hemorrhage was due to an occult optic glioma. Surgical evacuation of clotted blood resulted in improved visual function in three of the four cases.
Cerebrovascular moyamoya disease associated with an intracranial pseudoaneurysm
Authors: Yuasa Hiroshi , Tokito Sumitaka , Izumi Kazuo , Hirabayashi Kazuaki
Published: May 2009

✓ A 51-year-old woman became unconscious 19 hours after the onset of a headache. Computerized tomography disclosed an intracerebral hematoma in the left temporal lobe, with ventricular penetration. Angiography demonstrated the characteristic appearance of cerebrovascular moyamoya disease as well as an aneurysm-like shadow in the left temporal lobe, which proved on histological examination to be a pseudoaneurysm.
Lymphocytic adenohypophysitis of pregnancy simulating a pituitary adenoma: a distinct pathological entity
Authors: Baskin David S. , Townsend Jeannette J. , Wilson Charles B.
Published: May 2009

✓ Diffuse lymphocytic infiltration of the adenohypophysis occurring in temporal relation to pregnancy was found in two patients, each of whom had an intasellar mass with suprasellar extension that caused compression of the optic chiasm. The pathology and etiology of this lesion is discussed. This entity should be considered when evaluating patients with a pituitary mass lesion that presents in temporal association to pregnancy, particularly if there is evidence of hypopituitarism rather than a hypersecreting, endocrineactive adenoma.
An improved gravimetric measure of cerebral edema
Authors: Marmarou Anthony , Tanaka Kiyoaki , Shulman Kenneth
Published: May 2009

✓ Significant errors are introduced into the measurement of brain tissue water by the specific gravity technique when the edema fluid contains protein. Protein adds to the tissue solids, increasing the density of the tissue, and masks the proportional increase of brain water. Existing equations relating measured specific gravity and tissue water are not applicable, and a new formula was developed that compensates for the protein component of edema and reduces the experimental error. The new method was applied to the measurement of tissue water in cat brain made edematous by direct infusion of fluids of known composition and volume to test the theory. This technique for improving the gravimetric assessment of brain edema is presented.
Spinal cord compression by extradural fat after prolonged corticosteroid therapy
Authors: Guegan Yvon , Fardoun Raeph , Launois Bernard , Pecker Jean
Published: May 2009

✓ This young man was operated on twice for thoracic spinal cord compression. He had been on corticosteroid therapy for the last 2 years subsequent to a renal transplant. The only anomaly discovered during the operation was a large quantity of extradural fat that did not present the characteristics of lipoma. The remarkable postoperative clinical improvement suggested that the fat deposit was responsible for the spinal cord compression.
Spontaneous thrombosis of a giant intracranial aneurysm and ipsilateral internal carotid artery
Authors: Whittle Ian R. , Williams David B. , Halmagyi G. Michael , Besser Michael
Published: May 2009

✓ Computerized tomography revealed a thrombosed giant intracavernous carotid aneurysm in a man who presented with ophthalmoplegia and headache. Angiography confirmed complete aneurysmal thrombosis and also revealed complete occlusion of the ipsilateral internal carotid artery. Aneurysmotomy and thrombectomy produced substantial reduction in mass effect, with symptomatic improvement. The spontaneous thrombosis of giant intracranial aneurysms is discussed.
Interoptic course of the anterior cerebral artery associated with anterior cerebral artery aneurysm
Authors: Senter Howard J. , Miller Daniel J.
Published: May 2009

✓ A ruptured anterior cerebral artery aneurysm is reported in a patient in whom a solitary anterior cerebral artery arose from the proximal carotid artery and ascended between the optic nerves.
Dangers of collapsible ventricular drainage systems
Authors: Kaye Andrew H. , Wallace David
Published: May 2009

✓ Ventricular drainage systems employing a collapsible plastic bag for fluid collection were postulated to cause an increasing back-pressure produced in part by the elasticity of the bag. This postulate was shown to be correct in an experimental situation. There was a logarithmic rise in cerebrospinal fluid pressure as the bag filled. By increasing the size of the bag, the problem was overcome.
Oral glycerol for the treatment of traumatic intracranial hypertension
Authors: Wald Steven L. , McLaurin Robert L.
Published: May 2009

✓ Hyperosmolar agents are a primary therapeutic modality employed in the treatment of traumatic intracranial hypertension. Profound hyperosmolarity accompanied by systemic dehydration is a potentially serious problem when these drugs are used repeatedly for control of intracranial pressure. Because glycerol, a water-soluble alcohol, is metabolized in the liver, its dehydrating capacity may be reduced in comparison to other agents. A series of 15 patients were treated with oral glycerol (0.5 to 1.0 gm/kg) with only minor changes in serum electrolytes, glucose, and urea nitrogen. Serum osmolarity rose from a baseline of 305 mOsm/liter to 355 mOsm/liter after 10 days of therapy. Glycerol was found to be effective and safe when employed in this protocol and proved to be a valuable adjunct to the standard methods available for control of intracranial hypertension.
Effects of experimental fluid-percussion injury of the brain on cerebrovascular reactivity to hypoxia and to hypercapnia
Authors: Lewelt Wlodimierz , Jenkins Larry W. , Miller J. Douglas
Published: May 2009

✓ To test the hypothesis that concussive brain injury interferes with the normal vasodilator response of the cerebral circulation to hypoxemia, 30 cats were subjected to mild (PaO2 50 mm Hg) and severe (PaO2 30 mm Hg) hypoxemia while measurements were made of arterial and intracranial pressure, regional cerebral blood flow (CBF), and arterial blood gases. Ten cats served as controls, 10 were subjected to mild fluid-percussion injury of the brain (0.8 to 1.7 atmospheres (atm)), and 10 to severe injury (2.4 to 4.1 atm). The CBF response to hypercapnia (PaCO2 50 mm Hg) was also tested in most animals, and the response of CBF autoregulation to hemorrhagic hypotension was tested in four animals of each group. Trauma was found to severely attenuate the capacity of CBF to increase during hypoxemia. Responsiveness to hypoxemia appeared to be better preserved in traumatized animals than was autoregulation, but was less robust than the response to hypercapnia.
Effect of fibrin-fibrinogen degradation products on human basilar artery preparations
Authors: Lye Richard H. , Paul Kamal S. , Forster Christine M. , Whalley Eric T. , Dutton John
Published: May 2009

✓ Experiments were performed to determine the effects of fibrin-fibrinogen degradation products on the human basilar artery in vitro. Citrated plasma and streptokinase were incubated at 37°C to produce a preparation of fibrinogen degradation products. Aliquots of the incubate were obtained at 90 minutes, 48 hours, and 1 and 2 weeks after preparation, and were separated into fractions of different molecular weight (MWt), using an ultrafiltration technique. Each fraction was tested at each of the above times for contractile activity and possible interaction with a threshold concentration of 5-hydroxytryptamine (5-HT) on the human basilar artery. Contractile activity was initially confined to the 90-minute aliquot fraction MWt > 100,000, but as the incubation proceeded, such activity was also seen in the lower MWt fraction < 100,000 > 10,000 at all time intervals. This activity was never seen in the fraction MWt < 10,000 at any time. Enhancement of the 5-HT response was initially confined to the higher molecular weight fractions, but after 48-hour incubation all fractions showed this activity. It is suggested that products of fibrin-fibrinogen degradation may be involved directly or indirectly in influencing the pathophysiological mechanism(s) responsible for cerebral arterial spasm following subarachnoid hemorrhage.
The effect of blood transfusion, dopamine, and gamma hydroxybutyrate on posttraumatic ischemia of the spinal cord
Authors: Dolan Eugen J. , Tator Charles H.
Published: May 2009

✓ Posttraumatic spinal cord blood flow (SCBF) was assessed after elevating the mean systemic arterial pressure (mSAP) with a blood transfusion, or with an infusion of dopamine. The effect of the anesthetic agent, gamma hydroxybutyrate, was also assessed. Flows were measured using the 14C-antipyrine autoradiographic method. Animals were injured at T-1 by acute compression of the spinal cord with a clip exerting a pressure of 175 gm. Uninjured animals, with mSAP's of 120.0 ± 17.0 mm Hg, had gray and white matter flows of 74.2 ± 22.3 and 18.7 ± 6.7 ml/100 gm/min, respectively, while injured untreated animals had mSAP's of 82.5 ± 14.1 mm Hg and gray and white matter flows of 13.3 ± 12.1 and 3.9 ± 3.9 ml/100 gm/min, respectively, at the injury site. Blood transfusion raised the mSAP's to 127.5 ± 13.7 mm Hg in the injured animals and doubled the flows in gray and white matter to 25.6 ± 30.2 and 6.3 ± 6.4 ml/100 gm/min, respectively. Dopamine did not have as beneficial an effect as blood transfusion on either the mSAP (101.0 ± 16.7 mm Hg) or the SCBF (gray and white matter flows of 18.4 ± 12.4 and 5.8 ± 5.9 ml/100 gm/min). Gamma hydroxybutyrate (GHB) had almost no effect on the mSAP or SCBF of normal animals, and in injured animals produced only a unilateral increase in flow on the less severely injured side, without affecting the mSAP.
Closed recirculatory spinal subarachnoid perfusion for determining CSF dynamics
Authors: Artru Alan A. , Nugent Michael , Michenfelder John D.
Published: May 2009

✓ A new method for determining rates of cerebrospinal fluid (CSF) production under nonsteady-state conditions, namely, closed recirculatory spinal subarachnoid perfusion, was used to determine the effect of enflurane on the rate of CSF production in dogs. Considerable variability in results was observed such that there was no statistical difference in rates of production among animals that received enflurane 2.2%, enflurane 2.2% and nitrous oxide 60% to 70%, enflurane 3.2% and nitrous oxide 60% to 70%, or nitrous oxide 60% to 70% (controls). Possible sources of variability were sought in additional studies using a modification of the new method, and in an in vitro model. The results were compared to those obtained using an established method for determining rates of CSF production, namely, open ventriculocisternal perfusion. It was concluded that the sources of variability in the closed recirculatory method relate in part to adherence of the fluorescein-conjugated albumin tracer to glass and other surfaces, and to uneven flow and distribution of the tracer in the recirculatory system. When the open ventriculocisternal perfusion method was used, consistent results were obtained, demonstrating that CSF production rate increased significantly in animals that received enflurane. The authors conclude that the new closed recirculatory method is less reliable than the classical open perfusion method.
Intracranial hypoglossal schwannoma as an unusual cause of facial nerve palsy
Authors: Dolan Eugen J. , Tucker William S. , Rotenberg Dov , Chui Mario
Published: May 2009

✓ A case is presented in which facial palsy resulted from a hypoglossal schwannoma encircling the nerve in its course through the temporal bone.
Intraorbital optic nerve hemangioblastoma with von Hippel-Lindau disease
Authors: In Seiich , Miyagi Jun , Kojho Nobuto , Kuramoto Shinken , Uehara Masaki
Published: May 2009

✓ An intraorbital hemangioblastoma of the optic nerve is reported in a 23-year-old woman with von Hippel-Lindau disease. The absence of dural attachment and the microscopic findings were characteristic of hemangioblastoma. Four years later the patient developed a cystic hemangioblastoma in the left cerebellum which was successfully treated.
Cerebral hemangioma with glial neoplasia (angioglioma?)
Authors: Fischer Edwin G. , Sotrel Ana , Welch Keasley
Published: May 2009

✓ Two patients are reported who had intracerebral mass lesions composed of hemangioma and glial neoplasm. After excision, one recurred as an oligodendroglioma, and the remnant of the other remained static over a 5-year period. These lesions may represent a subgroup of cerebral hemangiomas that have the biological potential for future glial neoplastic growth. Reference is made to experimental work with polyoma virus which can induce cavernous hemangiomas in the central nervous system in mice, and which is a papovavirus. Other papovaviruses can induce ependymomas in hamsters.
Treatment of bilateral mycotic intracavernous carotid aneurysms
Authors: Eguchi Tsuneyoshi , Nakagomi Tadayoshi , Teraoka Akira
Published: May 2009

✓ A case of bilateral mycotic intracavernous carotid aneurysms is reported. Because of progressive bilateral ophthalmoplegia, the internal carotid artery (ICA) was ligated on both sides, combined with bilateral extracranial-intracranial arterial bypass. A superficial temporal artery-middle cerebral artery anastomosis was performed first on the right side followed by ligation of the right ICA at the neck. After an interval of 20 days, a bypass and ICA ligation was carried out on the left side. The patient developed mild hemiparesis and dysphasia during and immediately after the second operation, but these neurological deficits disappeared after elevation of systemic blood pressure.
Thoracic myelopathy secondary to ossified ligamentum flavum
Authors: Omojola Matthew F. , Cardoso Erico R. , Fox Allan J. , Drake Charles G. , Durward Quentin J.
Published: May 2009

✓ The authors report a case of ossification of the ligamentum flavum at T-10 and T-11 associated with compressive myelopathy. Metrizamide myelography with computerized tomography allowed precise preoperative diagnosis and anatomic localization of the lesion. The patient had satisfactory and prompt improvement after surgical intervention.
Dissecting hematoma of the cervical vertebral artery
Authors: Goldstein Steven J.
Published: May 2009

✓ A 31-year-old woman developed a sudden onset of vertebrobasilar ischemia while exercising. Cerebral arteriography revealed a dissecting hematoma of the cervical portion of the dominant vertebral artery. Both the neurological deficits and the intramural hematoma of vertebral artery resolved with conservative therapy alone.
Cerebrospinal fluid may nourish cerebral vessels through pathways in the adventitia that may be analogous to systemic vasa vasorum
Authors: Zervas Nicholas T. , Liszczak Theodore M. , Mayberg Marc R. , Black Peter McL.
Published: May 2009

✓ Cerebral blood vessels are devoid of vasa vasorum. Therefore, the authors have studied the microarchitecture of the adventitia of large feline cerebral vessels and systemic vessels of the same size, in an effort to determine how the vessels are nourished. The cerebral vessels contain a rete vasorum in the adventitia that is permeable to large proteins and is in continuity with the subarachnoid space. This substructure may be analogous to the systemic vasa vasorum and may contribute to the nutrition of the cerebral arteries.
Effect of intracranial pressure monitoring and aggressive treatment on mortality in severe head injury
Authors: Saul Thomas G. , Ducker Thomas B.
Published: May 2009

✓ During 1977–1978, 127 patients with severe head injury were admitted and underwent intracranial pressure (ICP) monitoring. All patients had Glasgow Coma Scale (GCS) scores of 7 or less. All received identical initial treatment according to a standardized protocol. The patients' average age was 29 years; 60% had multiple trauma, and 35% needed emergency intracranial operations. Treatment for elevations of ICP was begun when ICP rose to 20 to 25 mm Hg, and included mannitol therapy and drainage of cerebrospinal fluid (CSF) when possible. Forty-three patients (34%) had ICP greater than or equal to 25 mm Hg; of these, 36 (84%) died. The mortality rate of the entire group was 46%.

During 1979–1980, 106 patients with severe head injury were admitted and underwent ICP monitoring. Their average age was 29 years; 51% had multiple trauma, and 31% underwent emergency intracranial surgery. All patients received the same standardized protocol as the previous series, with the exception of the treatment of ICP. In this present series: if ICP was 15 mm Hg or less (normal ICP), patients were continued on hyperventilation, steroids, and intensive care; if ICP was 16 to 24 mm Hg, mannitol was administered and CSF was drained; if ICP was 25 mm Hg or greater, the patients were randomized into a controlled barbiturate therapy study. Twenty-six patients (25%) had ICP's of 25 mm Hg or greater, compared to 34% in the previous series (p < 0.05), and 18 of these 26 patients (69%) died. The overall mortality for this current series was 28% compared to 46% in the previous series (p < 0.0005).

This study reconfirms the high mortality rate if ICP is 25 mm Hg or greater; however, the data also document that early aggressive treatment based on ICP monitoring significantly lessens the incidence of ICP of 25 mm Hg or greater and reduces the overall mortality rate of severe head injury.
Pentobarbital changes compartmental contribution to cerebral blood flow
Authors: Laurent John P. , Lawner Pablo , Simeone Frederick A. , Fink Eugene
Published: May 2009

✓ Barbiturates were administered to normal dogs, establishing an isoelectric electrocorticogram. Cortical cerebral blood flows (CBF) and deeper CBF's were respectively measured by krypton-85 (85Kr) and xenon-133 (133Xe). Following barbiturate administration, the two methods of measuring CBF showed a poor coefficient of variation (r = 0.12, p < 0.05). The cortical flows decreased less than the fast compartment flows. A shifting of percentage contribution of flow to the slow compartment (60% increase, p < 0.001) was observed after barbiturate infusion. A selective shunting of blood flow to the slower areas may explain the lowering of intracranial pressure and protection of the deep white matter observed by many authors who use barbiturates in clinical and experimental situations.
Barbiturate protection in acute experimental spinal cord ischemia
Authors: Oldfield Edward H. , Plunkett Robert J. , Nylander William A. , Meacham William F.
Published: May 2009

✓ Ischemia is the pathophysiological mechanism in many types of spinal cord injury. In the present study, the infrarenal segment of the aorta was occluded for 25 minutes to produce spinal cord infarction in rabbits. Paraplegia occurred in 100% of control animals. Thiopental administered before aortic occlusion resulted in paraplegia in only 40% of animals so treated (p < 0.01). Histological study of the spinal cord demonstrated infarction of the gray matter in all paraplegic animals, whereas the microscopic appearance was normal in animals without neurological deficit. The protective influence of thiopental therapy in spinal cord ischemia was demonstrated.
Favorable results with syringosubarachnoid shunts for treatment of syringomyelia
Authors: Tator Charles H. , Meguro Kotoo , Rowed David W.
Published: May 2009

✓ From 1969 to 1979, 20 patients with syringomyelia were treated with a syringosubarachnoid shunt. The principal indications for this procedure were: significant progressive neurological deterioration and absent or minimal tonsillar ectopia. There were 15 patients with idiopathic syringomyelia, four with posttraumatic syringomyelia, and one with syringomyelia secondary to spinal arachnoiditis. The operations were performed with an operating microscope, and attention was directed to preserving the arachnoid membrane to ensure proper placement of the distal end of the shunt in an intact subarachnoid space. In all cases, a silicone rubber ventricular catheter was inserted into the syrinx through a posterior midline myelotomy.

The average follow-up period was 5 years. A favorable result was obtained in 15 of the 20 patients (75%), including an excellent result with improvement of neurological deficit in 11 patients and a good result with cessation of progression in four patients. In the remaining five patients the result was poor with further progression of neurological deficit. A short duration of preoperative symptoms was usually a favorable prognostic feature. Four patients with a history of less than 6 months all had excellent results. Thirteen patients had a syringosubarachnoid shunt only, and all had good or excellent results. Seven patients had other surgical procedures, before, accompanying, or after shunt placement, and two had favorable results. Thus, the syringosubarachnoid shunt is an effective therapeutic modality for many patients with syringomyelia, particularly if there is little or no tonsillar herniation.
Intracranial volume-pressure relationship in man
Authors: Tans Joseph Th. J. , Poortvliet Dick C. J.
Published: May 2009

✓ The pressure-volume index (PVI) was determined in 40 patients who underwent continuous monitoring of ventricular fluid pressure. The PVI value was calculated using different mathematical models. From the differences between these values, it is concluded that a monoexponential relationship with a constant term provides the best approximation of the PVI.
Reexpansion of previously collapsed ventricles: the slit ventricle syndrome
Authors: Hyde-Rowan M. Deborah , Rekate Harold L. , Nulsen Frank E.
Published: May 2009

✓ This study reports six cases of hydrocephalic children with the “slit ventricle syndrome” who evidenced reexpansion of the ventricular system following insertion of high-resistance valves and anti-siphon devices. The authors contend that slit ventricles and subsequent ventricular coaptation can be prevented by elimination or early replacement of low-resistance valves, and maintenance of normal- or nearly normalsized ventricles by shunt revision with valve upgrade and/or an anti-siphon device, as judged by the appearance of the ventricles on computerized tomography.
Herniated nerve root as a complication of spinal tap
Authors: Siddiqi Tariq S. , Buchheit William A.
Published: May 2009

✓ A case is described in which a patient suffered severe radicular leg pain following myelography. At surgery, a nerve root was found to be herniated through the dural puncture site. The leg pain was relieved after the dura was opened and the nerve root repositioned. The possible mechanism of such an injury is discussed.
Secondary adrenal insufficiency after intrathecal steroid administration
Authors: Chernow Bart , Vigersky Robert , O'Brian John T. , Georges Leon P.
Published: May 2009

✓ A 38-year-old man developed secondary adrenal insufficiency as a consequence of intrathecal methylprednisolone administration. Evidence in support of this diagnosis included an absent plasma cortisol response to insulin-induced hypoglycemia, an inadequate adrenal response to exogenous corticotropin stimulation, a typical delayed response to prolonged corticotropin infusion over 3 days, and the finding of an elevated level of prednisolone in the cerebrospinal fluid a full 2 months after its administration. It is therefore recommended that patients receiving intrathecal steroids be carefully observed for the possible development of secondary adrenal insufficiency.
Vertebrobasilar insufficiency secondary to vertebral artery occlusion from a fibrous band
Authors: Mapstone Timothy , Spetzler Robert F.
Published: May 2009

✓ A case is described in which vertebral artery occlusion, caused by a fibrous band, occurred whenever the patient turned his head to the right side, resulting in vertigo and syncope whenever the head was turned to the right. Release of a fibrous band crossing the vertebral artery 2 cm from its origin relieved the patient's vertebral artery constriction and symptoms.
Spontaneous carotid-cavernous fistula in osteogenesis imperfecta
Authors: Campos José-Maria de , Ferro Mario O. López , Burzaco Juan A. , Boixadós José R.
Published: May 2009

✓ A case of spontaneous carotid-cavernous fistula is presented in a patient suffering from osteogenesis imperfecta tarda type I. The patient was operated on under local anesthesia by intraluminal occlusion of the cavernous carotid artery with a Fogarty catheter, in accordance with Prolo's technique, with total remission except for homolateral loss of vision due to postglaucoma atrophy.

The pathogenetic phenomena described in the literature are reviewed, with the suggestion that osteogenesis imperfecta be included with Ehlers-Danlos disease, Marfan's syndrome, and pseudoxanthoma elasticum, as a connective tissue disease with increased weakness of vessel walls that can produce a spontaneous carotid-cavernous fistula. Reports of cases operated on by intraluminal occlusion with various types of balloon-tipped catheters are also reviewed. The good results obtained place this technique among the elective ones for the treatment of carotid-cavernous fistula.
Tuberculous brain abscess and its appearance on computerized tomography
Authors: Reichenthal Eli , Cohen Mathias L. , Schujman Elias , Eynan Nachman , Shalit Mordechai
Published: May 2009

✓ A case of tuberculous brain abscess in a 52-year-old woman is presented. The computerized tomographic (CT) scan demonstrated a multilocular space-occupying lesion in the right parietal area, surrounded by a thick hyperdense enhancing rim. It is suggested that a relatively long clinical history together with the appearance of a thick-walled abscess-like lesion on the CT scan may indicate the diagnosis of a tuberculous brain abscess.
Observer variability in grading patients with subarachnoid hemorrhage
Authors: Lindsay Kenneth W. , Teasdale Graham , Knill-Jones Robin P. , Murray Lilian
Published: May 2009

✓ The management of individual patients with subarachnoid hemorrhage depends greatly on assessment of the patient's clinical condition. Difficulty in applying current grading systems prompted the authors to conduct studies of observer variability and to attempt to identify sources of inconsistency. Observers graded 15 patients by both the Hunt and Hess and Nishioka systems. Considerable observer variability was found, with up to four different grades being selected for the same patient. Kappa statistics were used to evaluate the data. This method determines observer agreement occurring in excess of chance. Kappa values for each grading system showed observer agreement to be significantly better than chance, yet revealed marked observer variation. Most variation occurred when Grade 3 was selected, irrespective of the system used. In a further study where observers graded clinical summaries, similar variation occurred; therefore, inconsistency was due mainly to difficulty in matching patients with levels described in the grading system, rather than to fluctuation in the patients' clinical condition or difference in the observers' examination technique. Variability was high when patients with systemic disease or vasospasm on angiography were graded with the Hunt and Hess system. The studies show that a simpler and more reliable grading system is required, and emphasize the need for caution when interpreting the results from different published series.
Aminophylline plus nitroprusside and dopamine for treatment of cerebral vasospasm
Authors: Levy Walter J. , Bay Janet W. , Sawhny Bhupinder , Tank Thomas
Published: May 2009

✓ Cerebral vasospasm following subarachnoid hemorrhage continues to elude effective treatment. Volume expansion is very helpful at times, but cannot be relied on. The authors have combined elements of two vasospasm regimens that could have additive effects. After a trial of volume expansion, aminophylline, dopamine, and nitroprusside were used in combination in each of five patients. All had documented vasospasm and all improved markedly.
Barbiturate coma in focal cerebral ischemia
Authors: Selman Warren R. , Spetzler Robert F. , Roski Richard A. , Roessmann Uros , Crumrine Ralph , Macko Richard
Published: May 2009

✓ The therapeutic application of barbiturate-induced coma was evaluated in a primate model of focal cerebral ischemia. A standardized regimen of pentobarbital was used, and the times of initiation of administration were varied following a 6-hour middle cerebral artery occlusion in baboons. Three groups of five animals were treated at 30, 120, and 240 minutes after occlusion, while one group of five animals received no barbiturate therapy. Complete protection from intracranial pressure (ICP) elevation and ischemic damage was seen only in the group treated at 30 minutes. Those treated at 120 minutes, while doing better than untreated animals, still had ICP elevation and a marked neuropathological deficit. Animals treated at 240 minutes suffered a detrimental effect, in that malignant ICP and marked ischemic damage occurred earlier than in the untreated animals. The safe “therapeutic window” for barbiturate-induced coma in this animal model does not extend beyond 2 hours. Delayed administration results in a deleterious response and not merely a lack of protection.
Traumatic intracerebellar hematomas
Authors: Pozzati Eugenio , Grossi Claudio , Padovani Roberto
Published: May 2009

✓ Seven patients with “isolated” traumatic intracerebellar hematomas due to closed head injuries are presented. Computerized tomography parameters useful in the correct management of these hematomas include: location (hemisphere or midline), size, and appearance of the posterior fossa cisterns (intact or obliterated). Three patients with hemispheric hematomas were treated conservatively and recovered. One patient with a midline hematoma was managed conservatively and died. Three hematomas (one hemispheric and two midline) were operated on. The immediate results of surgery were good, but two patients died later due to medical complications. The results of this study support the concept that large hematomas (3 cm or greater) generally need surgery and that hemispheric hematomas of limited size (less than 3 cm) may be treated conservatively. The clinical course and prognosis of midline hematomas is grave, and evacuation of accessible hematomas should be considered early in the course of the disease.
Increased phospholipase C activity after experimental brain injury
Authors: Wei Enoch P. , Lamb Robert G. , Kontos Hermes A.
Published: May 2009

✓ Phospholipase C activity was measured in 1000 × G centrifuged cellular fractions isolated from cerebral cortical homogenates obtained from either control cats or cats subjected to experimental fluid-percussion brain injury. Phospholipase C activity was determined directly by measuring the Ca++-dependent conversion of membrane-bound, labeled phosphatidate to diacylglycerol or indirectly by measuring the diacylglycerol-dependent (brain diacylglycerol content) formation of phosphatidylcholine in the presence of labeled cytidine diphosphate (CDP) choline. Phospholipase C activity determined by either method was about two times greater in cell fractions isolated from animals subjected to brain injury than in controls (p < 0.01). The brain injury-induced rise in phospholipase C activity may be responsible, at least in part, for generating diacylglycerol that may be a source of free arachidonic acid that stimulates prostaglandin synthesis. These changes may account for the rise in brain prostaglandin levels that has been demonstrated earlier to occur after this type of brain injury.
Early decompression and neurological outcome in acute cervical spinal cord injuries
Authors: Wagner Franklin C. , Chehrazi Bahram
Published: May 2009

✓ To evaluate the effect on neurological outcome of spinal cord compression persisting after a closed injury, the authors reviewed 44 of 62 consecutively managed cases of cervical spinal cord and spine injuries at C3–7, inclusive. Decompression within 48 hours of injury was confirmed by myelography or open reduction. Neurological status, graded numerically on a spinal trauma scale at admission and at follow-up review (an average of 1 year ± 2 months after admission), and percent recovery of neurological deficit were compared to canal narrowing (22 severe, ≥ 30%; versus 22 moderate, 11% to 29%; or mild, ≤ 10%) and to delay before treatment (30 within 8 hours of injury versus 14 treated 9 to 48 hours after injury). Severe narrowing was equated with compression.

Status at admission and at follow-up review was positively correlated. Patients with admission scores of less than 2 recovered a mean of 15% of their deficit, while those with scores more than 2 recovered a mean of 77%. Admission status correlated significantly with spinal canal narrowing but not with vertebral body displacement. Time of treatment had no significant effect upon admission status and percent recovery. No significant difference in the percent of recovery was noted, whether decompression was early (up to 8 hours) or late (9 to 48 hours) after injury. Surgery did not significantly alter the percent of recovery.

The findings indicate that the initial injury to the cervical spinal cord and spine remains the primary determinant of neurological outcome. Severe canal narrowing with cord compression thereafter appears to have comparatively little effect. The conclusion that decompression is without effect is not possible without comparison with a group of patients whose spinal canals remained narrowed at follow-up review.
Effect of sympathectomy on spinal blood flow autoregulation and posttraumatic ischemia
Authors: Young Wise , DeCrescito Vincent , Tomasula John J.
Published: May 2009

✓ The hypothesis that the paravertebral sympathetic ganglia play a role in spinal blood flow regulation was tested in cats. Five cats were subjected to paravertebral sympathectomy, two to combined sympathectomy-adrenalectomy, three to adrenalectomy alone, and five controls received no treatment. Laminectomy was carried out to expose the T4–10 cord, and autoregulation was tested by measuring blood flow from the lateral columns with the hydrogen clearance technique during manipulation of systemic pressure with intravenous saline infusion and nitroprusside administration. The cord was then contused at T-7 with a 400 gm-cm impact injury. Posttraumatic blood flow was recorded, and neurophysiological function was assessed with somatosensory evoked potential (SEP) monitoring.

Before injury, blood flow in the untreated (control) group had no consistent relationship with mean systemic pressure over the range 80 to 160 mm Hg. In contrast, in all cats with paravertebral sympathectomy, whether accompanied by adrenalectomy or not, blood flows increased with systemic pressure (correlation coefficient 0.86, p < 0.01). After injury, the control and adrenalectomized cats showed blood flow decreases of > 60% to 4 to 6 ml/100 gm/min (p < 0.01) by 2 to 3 hours. However, cats with paravertebral sympathectomy maintained blood flow above 9 ml/100 gm/min for up to 3 hours after injury. All the sympathectomized cats recovered their SEP by the 3rd hour after injury, compared with none of the controls.

Thus, in the absence of the paravertebral sympathetic ganglia, spinal blood flow autoregulation was impaired and the typical posttraumatic loss in blood flow did not occur. The sympathectomy also protected the spinal cords from the neurophysiological loss usually seen in 400 gm-cm injury. The data suggest the need for caution in using acetylcholine blocking agents to paralyze animals in experimental spinal injury, since these agents alter sympathetic activity and may influence the injury process. The spinal cord is an excellent model in which to investigate sympathetic regulation of central nervous system blood flow.
Neurological toxoplasmosis presenting as a brain tumor
Authors: Tognetti Francesco , Galassi Ercole , Gaist Giulio
Published: May 2009

✓ A case of congenital toxoplasmic mass lesion is reported in an infant born to a mother who acquired Toxoplasma infection during her pregnancy. Radical surgery followed by chemotherapy appeared to be curative. Previously described cases of acquired and congenital mass lesions due to Toxoplasma infection are summarized. The possible delayed onset and the misleading features that congenital toxoplasmosis may display are stressed.
Carcinoma of the choroid plexus
Authors: Carpenter Duncan B. , Michelsen W. Jost , Hays Arthur P.
Published: May 2009

✓ Carcinoma of the choroid plexus is an extremely rare disease with a particularly virulent course. A case is reported in the left lateral ventricle of a young woman who is well 1 year after total excision of the tumor. The four previously reported patients with this disease who did well (two males and two females) were all children. Three of the four were treated with surgery followed by radiotherapy, and one with surgery alone. Although it appears possible that gross total removal may be curative, radiation therapy is suggested because of the distinct possibility that even the least aggressive-appearing lesions may degenerate and become rapidly fatal. Chemotherapy, although not used in any of the cases reported, is suggested as a possible adjunct in the treatment of this disease.
Intracranial pressure changes following aneurysm rupture
Authors: Voldby Bo , Enevoldsen Erna M.
Published: May 2009

✓ Continuous monitoring of intraventricular pressure (IVP) was performed before and during 13 recurrent hemorrhages occuring in 10 patients between the 3rd and 14th day after the initial rupture of an intracranial saccular aneurysm. Before re-rupture, nine patients were of Hunt and Hess' clinical Grade III or IV. Severe angiographic vasospasm was demonstrated in six patients. In the period between ruptures, IVP and mean arterial blood pressure were significantly increased compared to pressures in patients who did not rebleed. Ventricular drainage of cerebrospinal fluid (CSF) to a level of 25 mm Hg did not increase the rate of rebleeding (17% of patients). On the other hand, the use of drainage while the repeat rupture was taking place seemed to exert a deleterious effect on the natural mechanisms that lead to arrest of hemorrhage. In five patients with CSF drainage during their rebleed, the steady-state IVP level after the repeat rupture was significantly increased, and four patients died from large intracerebral hemorrhages. These results suggest that drainage of CSF should be avoided during recurrent hemorrhage, and should not be resumed until a steady-state IVP level has been reached.
Stereotaxic rostral mesencephalotomy in treatment of malignant faciothoracobrachial pain syndromes
Authors: Frank Franco , Tognetti Francesco , Gaist Giulio , Frank Giorgio , Galassi Ercole , Sturiale Carmelo
Published: May 2009

✓ Stereotaxic rostral mesencephalotomy was performed 19 times in 14 patients suffering from intractable pain syndromes due to malignant diseases. The satisfying results in terms of pain relief during a necessarily short follow-up period (mean 4.9 months) are outlined. Undesired side effects were mainly confined to oculomotor disorders, which partly subsided over the months following the operation. Some technical aspects of the procedure and the pertinent literature are briefly discussed.
Effect of trigeminal tractotomy on dental sensation in humans
Authors: Young Ronald F.
Published: May 2009

✓ Two patients with intractable pain of the head and neck due to cancer underwent trigeminal tractotomy and rhizotomy of the ninth and 10th cranial nerves, as well as an upper cervical dorsal rhizotomy. Postoperatively, cutaneous analgesia was present ipsilaterally in peripheral portions of the face and the neck, but paramedian facial regions and the oral mucosa were hypalgesic. The procedures had no significant effect on dental pain perception in these patients, as tested electrically and thermally. These results are similar to those in recent reports of dental sensation after trigeminal tractotomy in animals. The results raise questions about the validity of the commonly espoused hypothesis that trigeminal nucleus caudalis is the exclusive locus for processing of orofacial nociceptive information. The findings are consistent with the idea that the entire spinal trigeminal nucleus serves as a site for integration of painrelated information from orofacial structures that are supplied by afferent fibers in the fifth, seventh, ninth, and 10th cranial nerves and the upper cervical nerve roots.