bluuebunny/crossref_metadata_2025 huggingface dataset:
Circulatory disturbance of the spinal cord with epidural neoplasm in rats
Authors: Kato Amami , Ushio Yukitaka , Hayakawa Toru , Yamada Kazuo , Ikeda Hiroya , Mogami Heitaro
Published: May 2009

✓ An experimental model of spinal epidural neoplasm was produced in rats by injecting Walker 256 carcinoma cell suspension anterior to the T12–13 vertebral body. With this model, spinal cord blood flow (SCBF) and its response to CO2 inhalation were estimated by the carbon-14-antipyrine autoradiography and the hydrogen clearance methods. In the early stages after tumor implantation, weakness, axonal swelling, and edema of the white matter were observed, while both SCBF and its response to CO2 inhalation remained normal. In the next stage, the tumor invaded the spinal canal and compressed the spinal cord epidurally. The edema of the white matter progressed, while the gray matter was morphologically intact. The SCBF and its response to CO2 inhalation were altered at both the compression area and caudally in the spinal cord. Changes in response to CO2 inhalation appeared earlier than the SCBF decrease. In the last stage, the SCBF decreased rapidly to the critical level, producing irreversible nervous tissue damage. Microangiographic studies revealed extensive obliteration of the spinal epidural venous plexus and patency of the larger nutritional vessels. From the data obtained, the progressive vascular pathophysiology related to spinal epidural neoplasm is as follows: 1) the vertebral venous plexus is compressed and obliterated in the early stages of the disease, and vasogenic edema appears in the spinal cord; 2) as the tumor grows, mechanical compression of the spinal cord is added and the circulatory disturbance increases; and 3) in the last stage, SCBF decreases rapidly to a critical flow level, and the loss of cord function becomes irreversible.
Cervical facetectomy and its effect on spine strength
Authors: Raynor Richard B. , Pugh James , Shapiro Ilan
Published: May 2009

✓ Fourteen cervical spine motion segments consisting of two adjacent vertebral bodies and their connecting ligaments were tested in shear. Five had intact facet joints, five had bilateral facetectomy of 50% or less, and four had bilateral 70% facetectomy. Three to 5 mm of root could be exposed in the specimens with 50% facetectomy, and 8 to 10 mm in those with 70% facetectomy. Anterior-posterior shear tests were run alternately in compression and distraction. Facetectomy was found to have no effect on compression and distraction stiffness. Failure in the 70% facetectomized specimens was due to fracture of the remaining joint at 159 lbs. In the specimens with 50% facetectomy, a fracture load could not be established since failure of the specimen mounting occurred at 208 lbs, as it did in two of the specimens without facetectomy that were tested to failure. The difference in bone fracture at 159 lbs and mounting failure at 208 lbs is significant at p < 0.05. Bilateral resection of more than 50% of the facet joint significantly compromises the shear strength of a cervical spine motion segment.
Spontaneous hematomyelia secondary to Factor XI deficiency
Authors: Wisoff Jeffrey H. , Rovit Richard L. , Ho Victor , Leventhal Harvey
Published: May 2009

✓ A 34-year-old woman with Factor XI deficiency presented with rapidly progressive quadriplegia following a 1-week prodrome of cervical pain. At operation, a spontaneous hematomyelia was evacuated from the C4–6 vertebral level. The pathophysiology of spontaneous hematomyelia is discussed.
Postoperative paraplegia with preserved intraoperative somatosensory evoked potentials
Authors: Ginsburg Howard H. , Shetter Andrew G. , Raudzens Peter A.
Published: May 2009

✓ Intraoperative somatosensory evoked potentials (SSEP's) are being used with increasing frequency to monitor neurological function during spinal surgery. The authors report a case of postoperative paraplegia that occurred despite preserved intraoperative SSEP's in an achondroplastic dwarf who underwent correction of a congenital kyphoscoliosis. Surgeons and anesthesiologists involved with SSEP monitoring should be aware that false-negative results may occur with this technique.
Cerebral gumma
Authors: Hwang Wen-Zern , Hasegawa Takeshi , Ito Haruhide , Shimoji Takashi , Yamamoto Shinjiro
Published: May 2009

✓ A case of focal cerebral syphilitic gumma of the right temporal lobe is reported. Angiography showed moderate focal hypervascularity with stretched vessels, and irregularity of the vessel walls. Plain computerized tomography revealed an area of low density that enhanced strongly after intravenous administration of contrast medium.
Subarachnoid hemorrhage of unknown origin: prognosis and prognostic factors
Authors: Brismar Jan , Sundbärg Göran
Published: May 2009

✓ The cases of 127 consecutive patients with subarachnoid hemorrhage (SAH), in whom cerebral panangiography revealed no cause for the bleeding nor any sign of an intraparenchymatous hemorrhage, were reviewed in a study of the long-term prognosis and the possible prognostic factors in this condition. Data for all 127 patients in the study were obtained, with an average follow-up period of 5.4 years. After the 1st week post-SAH, only three rebleeds had occurred. In all, 80% of the patients had returned to full activity, 91% to at least part-time work; if the patients with hypertension were excluded, these figures rose to 86% and 95%, respectively. Decreased wakefulness on admission related to a slightly poorer prognosis, whereas age and red blood cell count in the cerebrospinal fluid had no prognostic significance.

Of those patients who, at the end of the 2nd week following the SAH, were fully awake and had not developed any symptoms of delayed cerebral ischemia (87% of all patients admitted), 88% returned to full activity, 97% to at least part-time work. The survival rate for this group, as well as causes of death, seem to be within the range for normal individuals. It should thus be possible to inform these patients (at least the normotensive ones) of the benignity of their condition, directly after normal angiography. Even among the patients who were able to return to full activity, symptoms attributable to the SAH were common: 22% experienced problems such as frequent headaches, vertigo, irritability, and increased fatigability.
CT myelography with intramedullary enhancement in cervical spondylosis
Authors: Iwasaki Yoshinobu , Abe Hiroshi , Isu Toyohiko , Miyasaka Kazuo
Published: May 2009

✓ The authors describe seven cases of cervical spondylosis in which small high-density areas were detected in the spinal cord on delayed computerized tomographic (CT) myelography. These high-density areas are believed to represent cavities or areas of cystic necrosis. In all seven cases the cervical spinal canal was narrow, and the spondylosis was located at multiple levels, causing a so-called “pincer effect.” On the CT scans the high-density areas resembled fried eggs in the gray matter. These areas were localized near the abnormal cervical discs. In two cases in which the Brown-Séquard syndrome was noted, the symptoms could be attributed to the morphology of the high-density area on the affected side of the cord. Following decompressive surgery, most of the symptoms improved except for numbness of the upper extremities and motor weakness of hands.
Juvenile pilocytic astrocytoma of the cerebrum in adults
Authors: Garcia Delia M. , Fulling Keith H.
Published: May 2009

✓ Seven adults (15 years of age or older) with juvenile pilocytic astrocytoma of the cerebrum were treated at Barnes Hospital in St. Louis, Missouri, from 1950 to 1981. This group comprised 7% of the total adult population with well differentiated astrocytoma and astrocytoma with anaplastic foci treated over a 30-year period. All seven patients were less than 30 years old at the time of presentation. The tumors were characterized by distinctive histology, a predilection for the temporal lobe, the presence of a major cyst, and relative gross circumscription making total surgical resection feasible. In contrast to patients with diffusely infiltrating cerebral astrocytoma, those with juvenile pilocytic astrocytoma have had an extremely favorable course, regardless of treatment. Four were treated with surgery alone after total gross tumor excision, and three received postoperative irradiation after subtotal excision. Six were alive 27, 24, 17, 9, 5, and 2 years after initial surgery. One patient died 7 years after surgery and radiation as a result of cerebral radiation necrosis. Juvenile pilocytic astrocytoma of the cerebrum is a recognizable, distinctive entity with natural history and pathological characteristics similar to the relatively benign cerebellar astrocytoma of childhood.
Pressure-volume conditions in patients with subarachnoid and/or intraventricular hemorrhage
Authors: Kosteljanetz Michael
Published: May 2009

✓ Pressure-volume conditions were studied in 17 patients with subarachnoid and/or intraventricular hemorrhage, who underwent continuous intracranial pressure (ICP) monitoring. The pressure-volume index (PVI) technique was used. The interrelationship between the ICP pulse amplitude and compliance was also examined. All patients were admitted in Hunt and Hess Grades II to V, and 11 had a proven aneurysm. The ICP was above 15 mm Hg in all patients during some part of the monitoring period. The pressure-volume conditions were abnormal in all patients. Median PVI was 12.7 ml (5.8 to 40.0 ml). The PVI did not correlate with ICP; the PVI based on bolus injection was significantly greater than PVI based on fluid withdrawal. The ICP pulse amplitude varied from 1.5 to 15 mm Hg and rose concomitantly with increasing ICP. Considering the pulsatile shift in intracranial blood volume as an endogenous bolus that increases ICP from the diastolic (Pdiast) to the systolic (Psyst) level, an equation was derived from the PVI model that describes the relationship between the Psyst:Pdiast ratio and the PVI.
Use of intrathecal morphine for postoperative pain relief following lumbar spine surgery
Authors: O'Neill Padraic , Knickenberg Christine , Bogahalanda Senarath , Booth Anthony E.
Published: May 2009

✓ A randomized prospective double-blind trial of intrathecal morphine for postoperative pain relief following lumbar spine surgery is described. Intrathecal morphine significantly reduced the mean pain score in the postoperative period (p < 0.01) and there was a corresponding significant reduction in the need for additional postoperative analgesia (p < 0.05). The possible mechanism of action of intrathecal morphine and the potential advantages of this technique are discussed. Possible side effects are also considered, and caution is urged until wider experience has been obtained.
Morphological studies of human arteriovenous malformations
Authors: Klara Peter M. , George Eugene D. , McDonnell Dennis E. , Pevsner Paul H.
Published: May 2009

✓ Ten patients with symptomatic arteriovenous malformations (AVM's) underwent embolization with isobutyl 2-cyanoacrylate (Bucrylate) delivered via a mini-balloon catheter according to the protocol of George and Pevsner. These patients underwent surgical removal of their embolized AVM, and surgical specimens were evaluated by light and scanning electron microscopy. Ten other patients with AVM's underwent surgical resection without prior embolization, and these surgical specimens were evaluated in a similar manner. Results from this study indicate that Bucrylate incites an inflammatory response characterized by foreign-body giant cells. This reaction was present as early as 3 weeks after embolization and persisted in specimens resected almost 1 year after the last embolization. No such reaction was observed in unembolized AVM's. Both light and scanning electron microscopy demonstrated a lattice structure of the Bucrylate embolus within the AVM vessels. These studies also demonstrated micro-channels within the Bucrylate embolus and the presence of what appears to be normal red blood cells within the latticework of the embolus. Vascular endothelium not in direct contact with the Bucrylate embolus retains a normal morphology as revealed by scanning electron microscopy.
Vicryl (polyglactin 910) mesh as a dural substitute
Authors: Maurer Paul Kurt , McDonald Joseph V.
Published: May 2009

✓ Many substances have been used as dural substitutes. Although the various materials are effective in a variety of settings, a material that is absorbed over time, elicits minimal inflammatory reaction, is relatively inexpensive, and is easily manipulated would be beneficial. An experimental project was conducted involving closure of dural defects in dogs with a Vicryl (polyglactin 910) mesh graft. Macroscopic and histological examination performed at various times after placement revealed resorption of the graft material, little cerebromembranous adhesion formation, and complete lack of injury to subjacent cortical zones. A substantial neomembrane forms over the zone of the mesh graft. The authors suggest that Vicryl mesh has significant potential as an absorbable, minimally reactive dural substitute.
Unusual delayed onset of diabetes insipidus following closed head trauma
Authors: Hadani Moshe , Findler Gideon , Shared Izhak , Sahar Abraham
Published: May 2009

✓ A case of delayed onset of diabetes insipidus (DI), which developed 27 days after a closed head injury, is reported. The patient sustained only a minor neurological deficit and, except for antidiuretic hormone (ADH) insufficiency, hypothalamic function was intact. This selective damage of posterior pituitary function was total and permanent. Ischemia due to vascular injury may be the most likely etiology. Once the diagnosis of delayed posttraumatic DI is confirmed, the treatment of choice is DDAVP (desmopressin acetate). In contradistinction to DI immediately following minor head injury, most patients with a delayed onset of DI after trauma have permanent ADH deficiency.
Extraneural metastasis of choriocarcinomatous element in pineal germ-cell tumor
Authors: Yoshida Kazunari , Toya Shigeo , Ohtani Mitsuhiro , Okui Shunichi , Takenaka Nobuo , Harigaya Kenichi
Published: May 2009

✓ A case of pineal germ-cell tumor producing human chorionic gonadotropin (HCG) and alpha-fetoprotein (AFP) is reported in a 23-year-old man. Extraneural metastasis developed during a course of combined chemotherapy after radiation therapy. Postmortem examination revealed that the metastatic pulmonary tumor was a choriocarcinoma, producing only HCG.
Radical resection of intramedullary spinal cord tumors in adults
Authors: Cooper Paul R. , Epstein Fred
Published: May 2009

✓ The management of patients with intramedullary spinal cord tumors is controversial. In the past, these tumors have often been treated with biopsy or subtotal removal followed by irradiation — a therapy that is usually associated with early tumor recurrence and progressive neurological impairment. In an attempt to improve on the outcome of patients with intramedullary tumors, the authors performed radical resection in most of the 29 adult patients who had surgery for these tumors within the past 30 months. The mean duration of symptoms was 9½ years, and all patients presented because of progressive neurological deficit.

Patients were evaluated with metrizamide myelography-computerized tomography scanning and intraoperative ultrasound imaging to define the site of the tumor and cystic components. There were 14 ependymomas, 11 astrocytomas, two lipomas, and one case each of intramedullary fibrosis and astrogliosis. Solid tumor spanned a mean of five spinal cord segments and 16 tumors were associated with cysts. Twenty tumors were in the cervical and/or cervicothoracic regions. Total removal was achieved in 14 patients and “99% removal” in seven others. In 21 of 29 patients (72%), the neurological condition was stabilized or improved as a result of the operation. Postoperative deterioration occurred for the most part in patients who could not walk or who had minimal motor function at the time of operation, and these patients are no longer considered as operative candidates. Radical resection of intramedullary tumors can be achieved, with stabilization or improvement of neurological deficit in the majority of patients.
Somatosensory evoked potentials evaluated in normal subjects and spinal cord-injured patients
Authors: Chabot Robert , York Donald H. , Watts Clark , Waugh Wendy A.
Published: May 2009

✓ Somatosensory evoked cortical potentials (SSEP's) were recorded in 27 healthy subjects using tibial and peroneal nerve stimulation with cephalic and non-cephalic references. Four major peaks were present in all recordings. Analysis of these components showed that SSEP's collected after tibial nerve stimulation with non-cephalic reference (linked earlobes) produced the most consistent clearly defined component peaks. Average latency, amplitude, and interpeak latency differences are presented for these SSEP's. Significant correlations were obtained between the height of the individual and the P1, N2, P2, and N3 latencies, and the N3-P1 interpeak latency. These results suggest that reproducible SSEP's can be obtained from tibial nerve stimulation in normal subjects using minimal numbers of stimulus presentations (28 to 64).

The SSEP's from 34 patients with varying degrees of spinal cord trauma were compared with the SSEP's from normal subjects. These comparisons involved the P1, N2, P2, and N3 latencies and the interpeak latency values, as well as the amplitude values. Patients with normal sensory and motor neurological examinations could be distinguished from patients showing decreased sensory and motor findings or clinically complete lesions on the basis of peak latency and interpeak latency values. The latter two groups could not be distinguished from one another. In general, all patient groups had SSEP's of lower amplitude than did normal individuals, but the groups could not be distinguished from one another. These results indicate that SSEP's can be a useful clinical tool for differentiation of complete from incomplete spinal cord lesions, but do not invariably predict recovery of function.
Safe use of PEEP in patients with severe head injury
Authors: Cooper Kevin R. , Boswell Peter A. , Choi Sung C.
Published: May 2009

✓ Thirty-three patients with severe head trauma were studied to determine whether the use of positive end-expiratory pressure (PEEP) would cause an increase in intracranial pressure (ICP). Changes in ICP induced by PEEP were then correlated with a panel of physiological variables to try to explain these changes. Mean ICP increased from 13.2 ± 7.7 mm Hg (± standard deviation) to 14.5 ± 7.5 mm Hg (p < 0.005) due to 10 cm H2O PEEP, but the eight patients with elevated baseline ICP experienced no significant increase. Cardiac output and venous admixture (Qs/Qt) declined significantly, while central venous pressure, peak inspiratory pressure, functional residual capacity, and arterial pCO2 increased significantly due to PEEP. Blood pressure and cerebral perfusion pressure were unchanged.

The change in ICP due to PEEP correlated significantly with a combination of cardiac output, peak inspiratory pressure, Qs/Qt, and changes in blood pressure and arterial pCO2 due to PEEP, indicating that the effect of PEEP on ICP could be largely explained by its effect on hemodynamic and respiratory variables. No patient deteriorated clinically due to PEEP. It is concluded that 10 cm H2O PEEP increases ICP slightly via its effect on other physiological variables, but that this small increase in ICP is clinically inconsequential.
Combined-modality treatment of osteogenic sarcoma of the skull
Authors: Sundaresan Narayan , Huvos Andrew G. , Rosen Gerald , Galicich Joseph H.
Published: May 2009

✓ The authors present the results of combined-modality treatment in eight patients with osteosarcoma of the skull. Six patients had de novo tumors, and two others had secondary sarcomas resulting from malignant transformation in Paget's disease. Wide surgical excision and combination chemotherapy were used in seven patients, and surgery and radiation therapy were employed in one case. Following chemotherapy, six patients underwent additional surgery. This aggressive approach resulted in four long-term survivors among the patients with de novo tumors. These data suggest that surgery in combination with chemotherapy provides the best potential for long-term disease control in patients with osteosarcoma of the skull.
Nimodipine levels in gerbil brain following parenteral drug administration
Authors: Heffez Dan S. , Nowak Thaddeus S. , Passonneau Janet V.
Published: May 2009

✓ Nimodipine binding to the particulate fraction of gerbil brain homogenate was characterized using tritiated (3H)-nimodipine as the radioactive ligand. Binding was monophasic and saturable, with the apparent affinity constant (KD) = 0.4 nM and the maximum number of binding sites (Bmax) = 12 nmol/kg wet wt. A competitive binding assay was validated for the measurement of nimodipine using gerbil brain as the source of receptors for the drug. Binding characteristics were sufficiently similar in specimens from different animals to allow the use of homogenates from individual animals as the source of both membrane-binding sites and competing ligand. Nimodipine could be detected in the brains of animals sacrificed soon after drug injection, and reached a peak level within 15 minutes. Brain drug level at a given time was a linear function of dose administered. One hour after a 1-mg/kg dose, the level of drug measured in brain was approximately 100 nmol/kg wet wt, more that 200 times the KD. Sufficient drug to mediate a maximal pharmacological effect accumulated in brain even after a dose of only 0.25 mg/kg. Thus, in this species, effective tissue nimodipine levels may be achieved at doses which minimize the risk of systemic hypotension.
Choroid plexus as a barrier to immunoglobulin delivery into cerebrospinal fluid
Authors: Aleshire Stephen L. , Hajdu Ivan , Bradley Charles A. , Parl Fritz F.
Published: May 2009

✓ The concentration of gamma globulins is greatly increased in the cerebrospinal fluid (CSF) during inflammatory and degenerative disorders of the central nervous system (CNS). The mechanism by which immunoglobulins enter the CSF under normal conditions is unknown. The extent of participation of the blood-brain barrier in protein delivery to the CSF is unclear, although the choroid plexus is known to have primary responsibility for the formation and movement of certain proteins into the CSF. To investigate the role of the choroid plexus in immunoglobulin delivery to the CSF, the authors evaluated rat brain tissue by light and electron microscopic immunohistochemical technique using the peroxidase technique of immunoglobulin (Ig)G and IgA detection. Peanut agglutinin was used to identify macrophages, cells known to have important immune functions and which have been reported as a normal component of the choroid plexus. Antisera to IgG and IgA demonstrated diffuse surface staining of the choroidal epithelial cells with light and electron microscopy; the cytoplasm and nuclei did not contain immunoglobulins. Macrophages were not present in the choroid plexus, in contrast to previous reports. The results demonstrate that immunoglobulins do not enter the CSF via the choroid plexus, unlike other proteins in similar concentrations in the CSF. In addition, macrophages are shown to be an insignificant component of the plexus, thereby further diminishing the likelihood of participation of the choroid plexus in the regulation of immunoglobulin entry into the CNS under normal conditions.
Deterioration of auditory evoked potentials during cerebellopontine angle manipulations
Authors: Sekiya Tetsuji , Iwabuchi Takashi , Kamata Shigeki , Ishida Takashi
Published: May 2009

✓ Evoked action potentials from the internal auditory meatus portion of the cochlear nerve (IAM-EAP's) and brain-stem auditory evoked potentials (BAEP's) from the vertex were simultaneously recorded during cerebellopontine angle (CPA) manipulations (retractions of the cerebellar hemisphere and the cochlear nerve) in dogs. The BAEP changes noted in these dogs were the same as those seen in patients. The IAM-EAP's showed graded deterioration related to BAEP changes. The results are as follows: 1) Prolongation of the I–V interpeak latency of BAEP's, the most common finding during CPA manipulations, is the reflection of prolongation of the I–II interpeak latency, which is caused by conduction impairment or block of the nerve impulses between the extracranial portion of the cochlear nerve and the brain stem. The operative manipulations representing stretch or compression injury to the cochlear nerve in the CPA leads to an acute traumatic cranial nerve root lesion — a retrocochlear lesion. 2) The obliteration of all BAEP components including wave I cannot be caused by conduction block. This is caused by occlusion of the internal auditory artery. Wave I of the BAEP's and the P1-N1 complex of the IAM-EAP's are important indicators of cochlear blood flow during surgical intervention. 3) As possible causes of internal auditory artery obstruction, mechanical distortion of the relationship between the anterior inferior cerebellar artery (AICA) and the internal auditory artery at the junctional portion, mechanical vasospasm of the AICA-internal auditory artery complex, and ensuing noreflow phenomena are discussed. 4) Evoked action potentials are expected to be a useful intraoperative real-time monitor during CPA surgery that can detect rapid changes derived from cochlear artery insufficency. The real-time aspects can overcome some of the disadvantages of BAEP monitoring.
Peripheral nerve stimulation suppression of C-fiber-evoked flexion reflex in rats
Authors: Sjölund Bengt H.
Published: May 2009

✓ Transcutaneous electrical nerve stimulation (TENS) is now a well established clinical technique to alleviate chronic pain. Its mechanism of action remains unknown and the stimulation parameters used are based on subjective reports from patients. In the present study, a systematic investigation has been performed with conditioning stimulation of different parameters delivered to a dissected skin nerve in the lightly anesthetized rat, utilizing the size of a C-fiber-evoked flexion reflex as a measure of transmission from nociceptive afferent fibers in the spinal cord. A stimulation intensity that recruited both A-beta and A-delta fibers was more effective in depressing the C-fiber-evoked reflex at all frequencies studied than were intensities activating A-beta fibers only. A stimulation frequency of 80 Hz gave the most profound inhibition. The implications for clinical treatment are discussed.
Regional brain metabolite levels following mild experimental head injury in the cat
Authors: Yang Mildred S. , DeWitt Douglas S. , Becker Donald P. , Hayes Ronald L.
Published: May 2009

✓ Glucose, adenosine triphosphate, phosphocreatine, and lactate levels in the cortex, striatum, diencephalon, hippocampus, cerebellum, and brain stem were measured in cats 1 hour after they were subjected to low-level (2 atm) fluid-percussion injury. Following injury, there was a mild but significant increase in lactate levels in the majority of regions studied. The hippocampus exhibited the highest percentage increase in lactate (fourfold). The cortical area directly under the trauma device showed a threefold lactate increase, while there was a twofold increase in other brain regions studied. Although there were consistent decreases in phosphocreatine levels, these decreases were significant only in the hippocampus (p < 0.05). Glucose levels in all brain regions studied were no different from control levels at the time of study. The unchanged glucose levels, together with previous studies of identically injured cats showing that cerebral blood flow was unimpaired, suggest that excess lactate was not a consequence of cerebral ischemia. Rather, the increase in lactate levels may indicate that concussive injury can produce a mild derangement of brain energy metabolism in the absence of substrate limitations. This derangement may reflect altered mitochondrial function.
Use of balloon occlusion and substances to protect ischemic brain during resection of posterior fossa AVM
Authors: Suzuki Jiro , Takahashi Akira , Yoshimoto Takashi , Seki Hirobumi
Published: May 2009

✓ The successful resection of a large posterior fossa arteriovenous malformation (AVM) is reported. A balloon catheter was used for temporary intraoperative occlusion of the basilar artery and feeding vessels of the AVM. Prior to occlusion of these arteries, newly tested substances to protect the ischemic brain were administered to prolong occlusion time. Resection of the AVM was completed without complication, and the patient returned to normal life. This is a useful intraoperative procedure for the resection of AVM's considered inoperable by conventional approaches.
Symptomatic root compression by a free fat transplant after hemilaminectomy
Authors: Cabezudo Jose M. , Lopez Alfredo , Bacci Fernando
Published: May 2009

✓ The authors report a case in which a free fat graft, placed at the operative site after hemilaminectomy for lumbar disc herniation, was forced into the spinal canal by action of the paraspinal muscles and behaved as a symptomatic space-occupying lesion. The patient recovered satisfactorily after the graft was removed. The pathogenetic mechanism is discussed and guidelines to avoid this complication are outlined.
Chronic subdural hematoma presenting as spontaneous subarachnoid hemorrhage
Authors: Kotwica Zbigniew , Brzeziński Jerzy
Published: May 2009

✓ Six cases of chronic subdural hematoma presenting with the clinical findings of acute subarachnoid hemorrhage are reported. No systemic or focal cause for the bleeding was found, and possible mechanisms are discussed.
Effect of perioperative platelet inhibition on postcarotid endarterectomy mural thrombus formation
Authors: Findlay J. Max , Lougheed William M. , Gentili Fred , Walker Paul M. , Glynn Michael F. X. , Houle Sylvain
Published: May 2009

✓ A prospective randomized double-blind trial was conducted to study the effect of platelet-inhibiting drugs on mural thrombus formation after carotid endarterectomy. Twenty-two patients undergoing carotid endarterectomy were randomly assigned to perioperative administration of an aspirin/dipyridamole combination or a placebo, and the postoperative results were compared. Autologous indium-111-labeled platelets were injected postoperatively, and platelet deposition was measured at the endarterectomy site. It was found that the treated group had a significant reduction in platelet accumulation compared with the placebo group. The results suggest that the perioperative use of aspirin/dipyridamole may reduce the risk of operative stroke and the long-term risk of repeat carotid stenosis.
Reduced systemic drug exposure by combining intra-arterial chemotherapy with hemoperfusion of regional venous drainage
Authors: Oldfield Edward H. , Dedrick Robert L. , Yeager Russell L. , Clark W. Craig , DeVroom Hetty L. , Chatterji Dulal C. , Doppman John L.
Published: May 2009

✓ Four patients with malignant cerebral gliomas received 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) into the internal carotid artery (ICA) while the ipsilateral jugular drainage was pumped extracorporeally through a hemoperfusion cartridge containing a nonionic adsorbant resin. Each patient received 220 mg/sq m BCNU, infused over 45 minutes through a toposcopic catheter positioned with the tip in the ICA beyond the origin of the ophthalmic artery. Jugular blood was pumped extracorporeally at 300 ml/min through a large-bore catheter in the jugular bulb. Plasma samples were obtained for BCNU measurement at frequent intervals from the right atrium. During a separate treatment, 6 weeks before or after the hemoperfusion treatment, the same dose of BCNU was infused into the ICA and atrial samples were obtained on a similar schedule.

Hemoperfusion of the jugular blood during intracarotid infusion reduced the systemic exposure by 56% to 87% and increased total body clearance of BCNU by two- to eightfold. The calculated pharmacokinetic advantage (brain:body exposure ratio) was between 21 and 55:1 when the combined treatment was used.
Comparison of computerized tomographic and radionuclide methods in determining intracranial cystic tumor volumes
Authors: Lunsford L. Dade , Levine Geoffrey , Gumerman Lewis W.
Published: May 2009

✓ The dosimetry of radioactive phosphorus (32P) for intracavitary treatment of cystic brain tumors is dependent upon accurate determination of the cyst volume. The authors have used both high-resolution computerized tomography (CT) scanning and an isotope dilution technique with technetium-99m (99mTc) sulfur colloid to determine cyst volumes in an experimental model and in six patients with intracerebral cystic tumors. In six separate comparisons using an experimental phantom “cyst,” no significant differences between CT and 99mTc values were detected. In six patients with cystic neoplasms varying from 3 to 6.7 ml in volume, the percent differences between values obtained by CT and isotope dilution ranged from −17.26% to +13.13%. In individual patients, these differences proved to be of little significance for planning dosimetry. In both experimental and clinical trials comparing isotope dilution and CT measurement techniques, the CT technique using the standard software of the scanner and 5-mm thick slices proved to be a highly accurate method of determining cyst volume. The authors now base dosimetric calculations for intracavitary radiation with 32P on CT technique alone.
Behavior of an extradural pressure monitor in clinical use
Authors: Powell Michael P. , Crockard H. Alan
Published: May 2009

✓ A comparison of intraventricular pressure (IVP) and extradural pressure (EDP) was carried out in 17 patients being investigated for normal-pressure hydrocephalus, and in six patients with acutely raised intracranial pressure following events such as head injury or intracerebral hematoma. Extradural pressure was measured using the CardioSearch monitor. There was a reasonably good correlation between EDP and IVP in the chronic stable group with pressures up to 25 mm Hg. In the acute group there was no predictable relationship between EDP and IVP, and during a 24-hour period the pressures could vary by as much as 30 mm Hg. Subdural pressure, measured with the same instruments, was compared to IVP in both acute and stable situations in eight other patients: there was a close and constant correlation between pressures in these two spaces. The authors conclude that misleading information may be obtained from EDP monitoring, and erroneous management decisions may result from dependence on such a technique. Possible explanations for this are discussed.
Centrocentral anastomosis in the prevention and treatment of painful terminal neuroma
Authors: González-Darder José , Barberá José , Abellán M. José , Mora Antonio
Published: May 2009

✓ In this experimental study, microsurgical centrocentral anastomosis was applied to an experimental model of painful terminal neuroma resulting from left sciatic nerve section in the rat. The anastomosis consisted of end-to-end suturing of the sciatic nerve fascicles to the tibial branch, with the interposition of a nerve graft taken from the same anastomosed fascicle. As a control parameter for the experiment, the autotomy which follows sciatic nerve section in the rat was evaluated. Autotomy is considered an objective indication of abnormal sensations that are provoked by the formation of a terminal neuroma. Histological study of the proximal stump of the sciatic nerve was also performed. The observation period was 10 weeks. The study demonstrates that centrocentral anastomosis reduces the size of the neuroma formation and the incidence of autotomy.
Acute effect of glycerol on net cerebrospinal fluid production in dogs
Authors: Zoghbi Huda Y. , Okumura Sada , Laurent John P. , Fishman Marvin A.
Published: May 2009

✓ The effect of glycerol administration on cerebrospinal fluid (CSF) formation in dogs was studied by means of a ventriculocisternal perfusion technique. Net CSF production rate decreased after oral administration of glycerol (3 gm/kg) from a baseline level of 42.33 ± 6.68 µl/min (mean ± standard error) to a trough of 10.33 ± 4.88 µl/min at 90 minutes after administration (p < 0.025). Serum osmolality concomitantly increased from a baseline value of 296 ± 2.83 to 309 ± 4.7 mOsm/kg H2O at 90 minutes. The mean percentage change in CSF production inversely correlated to the mean percentage change in serum osmolality, r = −0.85. Thus, glycerol administration decreases net CSF formation, and this effect may be related in part to the rise in serum osmolality.
Immunoregulatory role in gamma interferon production by a T cell growth factor-dependent experimental malignant glioma-specific cytotoxic T lymphocyte clone
Authors: Yamasaki Toshiki , Handa Hajime , Yamashita Junkoh , Watanabe Yoshihiko , Taguchi Masaaki , Kuwata Shigeki , Namba Yuziro , Hanaoka Masao
Published: May 2009

✓ The authors have established a murine malignant glioma-specific cytotoxic T lymphocyte clone (G-CTLL 1) by T cell growth factor (TCGF) using 203-glioma (a methylcholanthrene-induced ependymoblastoma of C57BL/6 mouse origin). The cloned cells were found to release a large amount of gamma interferon (IFN) in response to glioma-associated antigen-specific stimulation. The authors have investigated whether the IFN produced can contribute to killing the target cells. Adding anti-mouse gamma IFN antibody to the mixed clone-target cell culture inhibited IFN production by the cloned cells but the toxicity of the cells was minimally diminished. Therefore, it is suggested that the endogenous gamma IFN produced by the TCGF-dependent cloned cytotoxic T lymphocyte line does not have direct cytotoxic action on the target cells. Furthermore, IFN production as well as cytotoxicity was blocked by anti-Lyt-2 monoclonal antibody in the absence of complement. This suggests that IFN plays a role in the process of antigen recognition of target cells because the Lyt-2 molecule is involved in an antigen-specific function on the cytotoxic T lymphocyte receptor.

The role of TCGF in gamma IFN production was also investigated. The spontaneous production of gamma IFN by the cloned cells paralleled the amounts of exogenous TCGF added to the cultures, but TCGF had no synergistic effect on IFN production in the presence of mitogen or tumor antigen. Accordingly, it is possible that TCGF stimulates the cloned cells to proliferate, causing IFN release.
Carotid artery end-to-end anastomosis in the rat using the argon laser
Authors: Pribil Stefan , Powers Stephen K.
Published: May 2009

✓ Microvascular end-to-end anastomoses of rat common carotid arteries measuring 0.6 to 0.7 mm in diameter were performed using an argon surgical laser system. Vascular bonding with the argon laser was accomplished in all cases. The anastomosed carotid artery segments were evaluated both angiographically and histologically at 1 day, 1 week, and 1 month after laser bonding. With increasing time after anastomosis, there was a trend toward increasing angiographically proven stenosis of the anastomotic segment and histologically demonstrated pseudoaneurysm formation of the vessel wall at the bonded site. Pseudoaneurysm formation was associated with a dense inflammatory response in the anastomotic vessel segment. In spite of excellent initial tissue bonding and vessel patency, the delayed results of progressive vessel wall disruption and segmental stenosis indicate that further experience in using the argon laser for vessel welding is needed before this method can be accepted as an alternative to current microvascular suture technique.
Glycerol neurolysis: neurophysiological effects of topical glycerol application on rat saphenous nerve
Authors: Burchiel Kim J. , Russell Lisa C.
Published: May 2009

✓ The effect of topical glycerol application on normal and previously injured saphenous nerves was tested in 20 Sprague-Dawley rats. Anhydrous glycerol treatment of five normal nerves showed a rapid loss of C-fiber conduction within 5 minutes of application, while after 10 to 30 minutes, a complete conduction blockade in all fiber types was produced. The effect of anhydrous glycerol on both spontaneous firing from the neuroma and impulse propagation within the nerve was examined in 11 rats that had undergone saphenous neurotomy 7 days previously. In these animals, cessation of spontaneous action potential production from the neuroma was the earliest electrophysiological change noted, followed by loss first of C-fiber, then of A-fiber conduction. Graded concentrations of glycerol (25%, 50%, 75%, and 100%) were used in four rats with saphenous neuromas, which allowed selective blockade of spontaneous action potential generation and C-fiber conduction with minimal effect on A-fibers.

The neurophysiological mechanism of glycerol neurolysis appears to be a nonspecific conduction blockade of large and small fibers, which is established within minutes of its application. Spontaneous firing within damaged axons, which may play a role in a variety of cranial and peripheral nerve sensorimotor syndromes, is also exquisitely sensitive to glycerol application.
Treatment of ophthalmofacial-hypothalamic arteriovenous malformation (Bonnet-Dechaume-Blanc syndrome)
Authors: Morgan Michael K. , Johnston Ian H. , de Silva Merl
Published: May 2009

✓ A 17-year-old girl with unilateral blindness and exophthalmos was found to have Bonnet-Dechaume-Blanc syndrome without retinal arteriovenous communications. The arteriovenous malformation was managed by combined intracranial resection, ophthalmic artery ligation, and selective embolization of the external carotid component.
Subdural meningioma of spinal cord
Authors: Carter David A. , Rowed David W. , Lewis Anthony J.
Published: May 2009

✓ A case of extensive circumferential meningioma of the spinal subdural space is reported. A potential mechanism for this growth pattern is proposed, and preoperative diagnosis by computerized tomography is discussed. This case reinforces the necessity for intradural exploration when an expected extradural neoplasm is not encountered at operation.
Pleomorphic xanthoastrocytoma with 18-year survival
Authors: Palma Lucio , Maleci Alberto , Di Lorenzo Nicola , Lauro Giuliana M.
Published: May 2009

✓ The authors present a case of right parietal pleomorphic xanthoastrocytoma that occurred in a 24-year-old man. The patient was originally operated on in 1966, and at that time the diagnosis of monstrocellular sarcoma was made. The patient is still alive and totally symptom-free. A careful reevaluation of the microscopic findings, including positive glial fibrillary acidic protein staining, led to the definite diagnosis of pleomorphic xanthoastrocytoma.
Transsphenoidal surgery following unsuccessful prior therapy
Authors: Laws Edward R. , Fode Nicolee C. , Redmond Michael J.
Published: May 2009

✓ The authors report the results of a retrospective study conducted in an effort to define the results and risks of transsphenoidal surgery for patients whose prior therapy had failed. In a series of 1210 patients undergoing transsphenoidal surgery during a 10-year period, 158 had received prior therapy: 127 for pituitary adenoma, 20 for craniopharyngioma, and 11 for other lesions. Prior therapy was considered “direct” when it consisted of craniotomy or transsphenoidal surgery (either open or stereotaxic), and “indirect” when it consisted of radiation therapy, adrenalectomy, or bromocriptine therapy. The current transsphenoidal operation was performed for persistent hyperfunctioning endocrinopathy in 63 patients, for visual loss in 72 patients, and for cerebrospinal fluid (CSF) rhinorrhea in 21 patients. Success rates were as follows: normalization of endocrinopathy was achieved in 35% of cases; improvement or stabilization of vision in 59%; and successful repair of CSF rhinorrhea in 74%. The risks associated with repeat transsphenoidal surgery are significantly greater than the same procedure in a previously untreated patient.
Presentation of central nervous system sarcoidosis as intracranial tumors
Authors: Clark W. Craig , Acker James D. , Dohan F. Curtis , Robertson Jon H.
Published: May 2009

✓ Five cases of sarcoid presenting as an intracranial tumor are reported. In one instance, the lesion presented as a tumor in the cerebellopontine angle, a site not previously reported for the initial presentation of sarcoid isolated to the central nervous system. The role of computerized tomography, surgery, and steroid therapy is discussed. In the absence of pulmonary involvement, serum angiotensin-converting enzyme levels do not appear to be helpful in predicting steroid response.
Chiasmatic optic glioma treated with chemotherapy
Authors: Rosenstock Jeffrey G. , Packer Roger J. , Bilaniuk Larissa , Bruce Derek A. , Radcliffe Jerri-Lynne , Savino Peter
Published: May 2009

✓ Chiasmatic optic glioma is a rare tumor with an erratic natural history, usually seen in young children. A prior study from this institution demonstrated that these lesions were frequently lethal, despite initial clinical stabilization following radiation therapy, and that visual, intellectual, and late endocrinological disabilities were prevalent. A novel approach was developed in 1977, when an initial clinical response to vincristine was recorded in a child with a recurrent optic glioma. Since then, all children with recurrent optic glioma and all children aged 6 years old and under with newly diagnosed optic glioma have been offered a program of initial therapy with vincristine and actinomycin D for six cycles over 18 months. The four children with recurrent tumor who were treated with that regimen remain clinically stable 13 to 115 months after chemotherapy. Twelve children (eight under 24 months old) with newly diagnosed optic glioma have been treated with this program, and three are still on therapy. Four developed progression while on therapy, and five remain stable from 1 to 60 months posttherapy. The four children who developed progressive disease have been treated with radiation therapy and remain stable. Six of the 12 children showed shrinkage of their tumor on computerized tomography while receiving chemotherapy. This program may serve as an alternative to initial radiation therapy in young children.
Assessment of intracranial hemodynamics in carotid artery disease by transcranial Doppler ultrasound
Authors: Lindegaard Karl-Fredrik , Bakke Søren Jacob , Grolimund Peter , Aaslid Rune , Huber Peter , Nornes Helge
Published: May 2009

✓ Noninvasive transcranial Doppler recordings were correlated to the angiographic findings in 77 patients with carotid artery disease. Stenoses reducing the luminal area of the internal carotid artery by 75% or more also reduced the pulsatility transmission index (PTI) of the ipsilateral middle cerebral artery (MCA). The PTI is the pulsatility index of the artery under study expressed as a percent of the pulsatility index of another intracranial artery with presumed unimpeded inflow in the same individual. For stenoses in the 75% to 89% category, PTI reduction was significantly greater in patients with bilateral carotid stenosis, indicating an impaired potential for collateral flow in these patients. The PTI reduction probably reflects both the pressure drop across the stenosis and the cerebral autoregulatory response. Two criteria proved useful in demonstrating collateral MCA supply through the circle of Willis. On the recipient side, retrograde flow in the proximal anterior cerebral artery was demonstrated in 29 of the 31 patients when this flow pattern was disclosed angiographically. In 26 of these patients, the anterior cerebral artery on the supplying side also had clearly increased flow velocity. Increased flow velocities in the proximal posterior cerebral artery were present in 26 of the 30 vessels that were acting as a collateral channel to the ipsilateral MCA.