bluuebunny/crossref_metadata_2025 huggingface dataset:
The recurrence of intracranial meningiomas after surgical treatment
Authors: Adegbite Andrew B. , Khan Moe I. , Paine Kenneth W. E. , Tan Leonard K.
Published: May 2009

✓ A study of 114 surgically treated patients with intracranial meningiomas was carried out to evaluate factors influencing recurrence. The date of the initial surgery extended over a 24-year period from January, 1956, to December, 1979. The patients ranged in age from 1½ years to 82 years. Seventy-one (62.3%) were females and 43 (37.7%) were males. The surgical procedure was graded according to Simpson's classification from 1 to 5 (Grade 1 = complete excision, Grade 5 = simple decompression). In this series, 33 procedures (28.9%) were Grade 1, 55 (48.2%) were Grade 2, seven (6.1%) were Grade 3, 18 (15.8%) were Grade 4, and one (0.9%) was Grade 5. There were eight (7%) postoperative deaths.

Approximately 60% of the tumors were located in the sphenoid wing (23.7%), convexity (21.1%), and parasagittally (14.9%). Histological diagnosis in 96% of the patients was transitional (42.1%), syncytial (34.2%), and fibroblastic (20.2%) meningiomas. Eight (7%) patients received postoperative radiotherapy. There was evidence of recurrence in 22 patients (19.3%). Twenty-one underwent a second surgical procedure. Using survival analysis, it was determined that 80% of the patients were free of recurrence 5 years after the initial surgery, and approximately 50% showed no recurrence 20 years after the initial surgery. Only the grade of the initial surgery had a statistically significant influence on recurrence. Sex of patients, site and histology of the tumor, and postoperative radiotherapy had no statistically significant influence on recurrence. Angioblastic and malignant meningiomas were rare (only four cases), and recurred relatively quickly.
Pharmacologically induced profound arterial hypotension in the anesthetized dog
Authors: Kassell Neal F. , Boarini David J. , Sprowell James A. , Olin Julie J.
Published: May 2009

✓ The purpose of this study was to compare the behavioral, hematological, and biochemical effects of profound arterial hypotension induced by adenosine potentiated with dipyridamole with those of hypotension induced by trimethaphan camsylate or sodium nitroprusside. Twenty dogs were anesthetized with halothane and nitrous oxide, paralyzed with pancuronium, and ventilated to an arterial pCO2 of 40 torr. Arterial pressure and heart rate were monitored continuously. The animals were divided into four groups of five dogs each. The first group served as controls, while in the remaining groups the mean arterial pressure (MAP) was lowered to 40 mm Hg with adenosine/dipyridamole, trimethaphan, or nitroprusside for 1 hour, following which the animals were allowed to recover from the anesthetic and observed for 48 hours. Determinations of arterial blood gases and hematological and biochemical parameters were made immediately prior to and at the completion of the 1-hour hypotensive period and 48 hours later.

Reduction of MAP to 40 mm Hg was readily achieved with adenosine/dipyridamole. There was no tachyphylaxis to this drug, and arterial pressure promptly returned toward control levels without overshoot after the infusion was discontinued. In contrast, hypotension of this degree could be produced only with toxic doses of nitroprusside. Trimethaphan was more effective in producing hypotension than nitroprusside, but the dose required was extremely variable, and prolonged intervals were required for pressure to return toward normal after the agent was stopped. The control animals and those that received adenosine/dipyridamole recovered promptly from the anesthetic and were neurologically intact. The animals that received trimethaphan recovered more slowly but were neurologically normal within 12 hours. All of the animals that received nitroprusside died without recovering from the anesthesia. Aside from a mild transient metabolic acidosis and transient elevation of blood urea nitrogen and creatinine in the dogs that received adenosine/dipyridamole or trimethaphan, no specific cardiovascular, hematological, hepatic, or renal toxic effects were noted. Evidence of fatal cyanide toxicity was present in the nitroprusside group.

These data suggest that hypotension using adenosine/dipyridamole is readily induced, maintained, and reversed, and is not associated with any apparent hematological, or biochemical evidence of toxicity. Further studies leading to a clinical trial of adenosine-induced hypotension appear to be indicated.
Microsurgical removal of a balloon embolus to the internal carotid artery
Authors: Chalif David J. , Flamm Eugene S. , Berenstein Alex , Choi In Sup
Published: May 2009

✓ A complication of treatment of posttraumatic carotid-cavernous fistulas by detachable balloon techniques is presented. During occlusion of the fistula, a balloon embolus migrated from the cavernous sinus into the bifurcation of the internal carotid artery. The resultant neurological deficit was immediately treated with hypertension and volume expansion. The patient underwent direct microsurgical embolectomy and suffered no postoperative neurological sequelae. The significance and management of this complication are discussed.
Bilateral aneurysm formation developing from junctional dilatation (infundibulum) of the posterior communicating arteries
Authors: Itakura Toru , Ozaki Fuminori , Nakai Ekini , Fujii Toru , Hayashi Seiji , Komai Norihiko
Published: May 2009

✓ The authors report a case in which bilateral aneurysms developed from junctional dilatations of the posterior communicating arteries. A 7-year follow-up study of this case strongly suggested that an infundibulum can develop into a true aneurysm. After reviewing seven cases in the literature, the authors conclude that junctional dilatations, especially in young women with a history of aneurysmal rupture, should be carefully followed by angiography.
Stem cell studies of human malignant brain tumors
Authors: Rosenblum Mark L. , Gerosa Massimo A. , Wilson Charles B. , Barger Geoffrey R. , Pertuiset Bertran F. , Tribolet Nicolas de , Dougherty Dolores V.
Published: May 2009

✓ A stem cell assay for human malignant gliomas has been developed. Cells obtained from tumor biopsies grew into colonies composed of malignant glial cells, as documented by histochemical, immunohistochemical, and immunobiological techniques. Studies suggest that the disaggregated cells are representative of the cells within the solid tumor.

Clonogenic cells were obtained from 48 tumors and analyzed for their in vitro sensitivity to graded doses of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). The in vitro anti-tumor activity of BCNU at clinically achievable doses was compared to clinical response to the agent based on changes in computerized tomographic scan, radionuclide brain scan, and neurological examinations. Twenty-two patients received nitrosoureas before or after tumor specimen analysis, and were eligible for in vitro-in situ correlations. Clinical tumor sensitivity to nitrosoureas was predicted by culture results in 42% of all evaluable patients, and clinical resistance was predicted in 100%. The capability of the assay can be appreciated best for the 13 patients not treated with BCNU prior to culture; the in vitro prediction of clinical sensitivity and resistance was 71% and 100%, respectively.

Preliminary findings show that clinical tumor resistance to BCNU may result from “intrinsic” cell resistance in some patients and from inadequate delivery of drug to tumor cells in other cases. The potential utility of this method to study the reason(s) for tumor cell resistance to drugs, to screen new chemotherapeutic agents, to individualize patient treatment, and to investigate tumor biology is discussed.
Arnold-Chiari malformation
Authors: Paul Kamal S. , Lye Richard H. , Strang F. Alexander , Dutton John
Published: May 2009

✓ The natural history of symptomatic adult Type I Arnold-Chiari malformation (ACM) is variable, and the value of surgery in the management of this disease is difficult to assess. A series of 71 patients in whom a diagnosis of Type I ACM was confirmed at operation is presented, and the progress of the patients following posterior fossa decompression is analyzed. The length of history varied greatly. Pain was the commonest symptom (69% of patients); other symptoms included weakness (56%), numbness (52%), and unsteadiness (40%). The presenting physical signs consisted of a foramen magnum compression syndrome (22%), central cord syndrome (65%), or a cerebellar syndrome (11%). Myelography was performed in 69 patients, and was the most useful investigation. Only 23% of plain radiographs were abnormal. In addition to tonsillar descent, the operative findings included arachnoid adhesions (41%) and syringomyelia (32%). All patients underwent suboccipital craniectomy and C1–3 laminectomy. Respiratory depression was the most frequent postoperative complication (14%), and one patient died from sleep apnea. Early postoperative improvement of both symptoms (82%) and signs (70%) was followed by later relapse in 21% of patients, showing an initial benefit following surgery. None of the patients with a cerebellar syndrome deteriorated, whereas 56% of patients with evidence of foramen magnum compression and 66% of those with a central cord syndrome maintained their initial improvement. The authors conclude that posterior fossa decompression appears to benefit some patients, although a significant proportion might be expected to relapse within 2 to 3 years after operation, depending upon the presenting syndrome.
Pressure-absorption responses to the infusion of fluid into the spinal cord central canal of kaolin-hydrocephalic cats
Authors: Nakamura Shigetoshi , Camins Martin B. , Hochwald Gerald M.
Published: May 2009

✓ The resistance to cerebrospinal fluid (CSF) absorption through the alternative CSF absorption pathway in kaolin-induced hydrocephalic cats was measured by the constant infusion-manometric test. The cerebral ventricles were bypassed, and artificial CSF was infused directly into the central canal of the spinal cord. The infusion rates were increased stepwise from 0.022 to 0.168 ml/min when the capacity to absorb CSF was exceeded. There was an initial increase in resistance which was associated with the emergence of infusion fluid through a slit-like opening in the dorsal columns of the lower lumbar spinal cord. The resistance to flow decreased when the infusion rate was greater than 0.086 ml/min. Fluid accumulated in the spinal subarachnoid space when the ability to absorb was exceeded. The diversion of this fluid caused the pressure in the spinal cord central canal to fall rapidly. The results suggest that the CSF absorption deficit in chronic kaolin-induced hydrocephalic cats is probably caused by the restriction of CSF flow from the central canal through the spinal cord and into the spinal subarachnoid space. As a result of kaolin, the central canal is sufficiently dilated to permit, during infusion, the flow of at least five times as much CSF as the hydrocephalic cats produce. It is not clear whether the overloading of the CSF absorption mechanism is due to the restrictions imposed by the size of the subarachnoid space, or to the structures in this space involved with the return of CSF to the blood.
The role of intracranial hypotension in neonatal intraventricular hemorrhage
Authors: Conner E. Scott , Lorenzo Antonio V. , Welch Keasley , Dorval Brent
Published: May 2009

✓ Most preterm infants develop transient intracranial hypotension, which reaches its lowest level on the 2nd day of life. This corresponds to the time when most neonatal intraventricular hemorrhage (IVH) occurs. In order to test the hypothesis that intracranial hypotension may have an etiological role in the development of IVH in premature infants, the authors induced intracranial hypotension in the preterm rabbit by the intraperitoneal injection of glycerol. The rabbit model is well suited for this study because this animal is at risk of developing spontaneous germinal matrix and ventricular hemorrhage. Compared to control littermates, the glycerol-treated animals exhibited a greater than 3.5-fold incidence of germinal matrix and intraventricular hemorrhage.
Failure of prophylactically administered phenytoin to prevent late posttraumatic seizures
Authors: Young Byron , Rapp Robert P. , Norton J. A. , Haack Dennis , Tibbs Phillip A. , Bean James R.
Published: May 2009

✓ This randomized double-blind placebo-controlled study was undertaken in a series of 179 patients to determine whether phenytoin administered soon after head injury lessens the incidence of late posttraumatic epilepsy. When delayed hypersensitivity to phenytoin developed, the patient was switched to phenobarbital. The patients were followed for 18 months to detect the occurrence of seizures and to serially measure plasma phenytoin concentrations. There was no significant difference in the percentage of patients having late seizures in the treated and placebo groups (p = 0.75). The time between injury and seizures did not significantly differ between the two groups. The results provide no support for the continued use of phenytoin in the low therapeutic range for prophylaxis against late posttraumatic seizures.

It cannot be concluded that higher phenytoin plasma concentrations and higher compliance rates than obtained in this study would not have significantly decreased the occurrence of late posttraumatic epilepsy. The finding that no patient with a phenytoin plasma concentration of 12 µg/ml or higher had a seizure raises the question of whether phenytoin in blood concentrations in higher therapeutic ranges might lessen the occurrence of posttraumatic epilepsy, and should be studied further. Posttraumatic epilepsy is a major public health problem deserving a large cooperative trial to determine if phenytoin at higher blood levels than obtained in this study, or other currently available or newly developed drugs, can prevent the occurrence of posttraumatic epilepsy.
Sedimentation level in chronic subdural hematoma visible on computerized tomography
Authors: Kao Ming-Chien
Published: May 2009

✓ A clear interface dividing subdural hematoma into an upper hypodense and a lower hyperdense part was seen on computerized tomography (CT) scan in seven of 140 patients with chronic subdural hematoma. All except one of the seven patients had a definite history of head trauma more than 1 month before they developed acute disturbances of consciousness and pronounced hemiparesis. Consequently, they remained bed-ridden until they underwent drainage of the subdural hematoma. This group was compared to seven chronic subdural hematoma patients with mild clinical manifestations who were selected and intentionally confined to bed for a period before CT examination and craniotomy. The CT scans in this latter group did not show the clear interface in the subdural hematoma seen in the first group. Based on this study, it is hypothesized that this sedimentation level occurred as a result of rebleeding into a chronic hematoma that was sufficiently old to result in its contents being homogenous prior to the rebleed. In cases of rebleeding, a sufficient period of bed confinement in the brow-up position before CT examination allows development of a gravitational sedimentation in the hematoma. This clear level of sedimentation is seen in only a small portion of patients, but this finding may be specific for a significant amount of rebleeding and may herald acute deterioration.
Acute subdural hematoma and death following lateral cervical spinal puncture
Authors: Rogers Larry A.
Published: May 2009

✓ An acute subdural hematoma dissecting into the posterior cranial fossa and resulting in death is reported. The patient had undergone spinal puncture by the lateral cervical technique prior to development of the hematoma. Autopsy demonstrated that the source of hemorrhage was an anomalous intraspinal vertebral artery.
Balloon occlusion of a spontaneous fistula of the posterior inferior cerebellar artery
Authors: Viñuela Fernando , Fox Allan J. , Kan Shinichi , Drake Charles G.
Published: May 2009

✓ A case is reported of a large spontaneous right posterior inferior cerebellar artery fistula in which the patient presented with a right cerebellopontine (CP) angle and right cerebellar syndrome. The patient was successfully treated by balloon occlusion at the fistula site. The location of the arteriovenous fistula, the mass effect of its enlarged draining veins on the cerebellum and CP angle structures, and the simple therapeutic endovascular occlusion with a detachable balloon make this case unique.
Parkinsonism due to subdural hematoma
Authors: Sandyk Reuven , Kahn Iqbal
Published: May 2009

✓ The authors describe the case of a 38-year-old woman who presented with parkinsonian syndrome associated with chronic subdural hematoma. Gradual disappearance of the symptomatology followed removal of the hematoma. Chronic subdural hematoma may in rare instances cause a parkinsonian syndrome, probably by a pressure effect on basal ganglia structures or by altering the function of neurotransmitters.
Lipoma of the insula
Authors: Hatashita Shizuo , Sakakibara Tokiwa , Ishii Shozo
Published: May 2009

✓ The authors present a case of lipoma of the insula. This 20-year-old man with grand mal seizure was diagnosed by computerized tomography, and improved satisfactorily following surgical intervention.
Transient global amnesia associated with a single metastasis in the non-dominant hemisphere
Authors: Findler Gideon , Feinsod Moshe , Lijovetzky Graciela , Hadani Moshe
Published: May 2009

✓ A patient in whom transient global amnesia (TGA) led to the diagnosis of a metastasis of a transition-cell carcinoma of the bladder to the non-dominant hemisphere is described. In previously reported cases of TGA associated with brain tumors, the tumors involved either the dominant or both hemispheres. The etiology of TGA associated with a brain tumor is most likely vascular, as suggested by the sudden development and the transitory character of the event. In contrast to the “common” form of TGA (where both temporal lobes suffer temporary ischemia), in these patients only one side of the limbic system is affected, because a brain tumor has already compromised the other limbic area. Therefore, the dominance of the hemisphere with the tumor is of no consequence, as both hemispheres have been involved. It is concluded that the TGA in these patients is not due to, but is rather associated with, a unilateral brain tumor.
Pituitary apoplexy treated by transsphenoidal surgery
Authors: Ebersold Michael J. , Laws Edward R. , Scheithauer Bernd W. , Randall Raymond V.
Published: May 2009

✓ The authors report 13 patients with pituitary apoplexy who were treated at their institution between November, 1972, and September, 1982. The uncommon nature of this syndrome is suggested by the fact that, during this same period of time, 940 patients were treated for pituitary adenoma by transsphenoidal surgery. It is evident that prompt and accurate diagnosis of pituitary apoplexy is necessary to achieve optimal results from treatment. Although large hemorrhages occasionally necessitate craniotomy to decompress the suprasellar structures, usually this condition can be satisfactorily treated by transsphenoidal decompression and, in most cases, this is the procedure of choice.
Bleeding from cerebral arteriovenous malformations as part of their natural history
Authors: Graf Carl J. , Perret George E. , Torner James C.
Published: May 2009

✓ The case records of 191 patients with a cerebral arteriovenous malformation (AVM) were reviewed to determine bleeding characteristics of these lesions. Possible influences of age, sex, the location and size of the AVM, type of initial hemorrhage, and condition of the patients were analyzed. Of these 191 patients, 102 had a single hemorrhage, 32 had a recurrent hemorrhage, and 57 never bled. The follow-up period for patients with an unruptured AVM was a mean of 4.8 years and a maximum of 31 years; for those with a ruptured AVM, the mean was 2 years, and the maximum 37 years.

Size of the AVM was significantly related to the risk of first hemorrhage. The average yearly risk for first hemorrhage was between 2% and 3%. Bleeding occurred most frequently in the 11- to 35-year-old age group. The risk of rebleeding increased with advancing age. Among 93 patients followed after their AVM had ruptured, the risk of rebleeding was 6% in 1 year. After the first year, the average rebleeding rate was about 2% per year up to 20 years.
The blood-brain barrier following experimental subarachnoid hemorrhage
Authors: Peterson Eric W. , Cardoso Erico R.
Published: May 2009

✓ In three groups of cats, the authors studied the effect of subarachnoid hemorrhage (SAH) on the permeability of the blood-brain barrier (BBB) to the penetration of Evans blue-protein complex. One group received arterial hypertension alone, one group SAH alone, and one group SAH followed by arterial hypertension. Animals subjected to arterial hypertension alone showed areas of BBB breakdown. However, when cats were rendered hypertensive after SAH, there were no demonstrable BBB lesions. The SAH was produced by intracisternal injection of whole blood and hypertension by the intravenous injection of metaraminol. The preservation of the BBB after SAH is discussed. Vasospasm is considered as a possible hemodynamic variable responsible for the protection of the BBB from hypertensive damage. The need for a new model is proposed to further investigate the state of the BBB after SAH.
The blood-brain barrier following experimental subarachnoid hemorrhage
Authors: Peterson Eric W. , Cardoso Erico R.
Published: May 2009

✓ Under controlled physiological conditions, fresh blood was injected into the cisterna magna of 10 adult cats to produce subarachnoid hemorrhage (SAH). Damage to the blood-brain barrier (BBB) was induced 30 minutes after SAH by the intracarotid injection of a 6 × 10−5M solution of mercuric chloride (HgCl2). A control series of five cats received the same injection of HgCl2. Intravenously injected Evans blue dye was used to indicate areas of BBB damage. The lesions were confirmed by fluorescence microscopy. All control animals showed BBB damage in the hemisphere injected with HgCl2. Of the animals in the test group with SAH, 90% were free from lesions. When lesions were present, the distribution differed from that in the control group. These results bear a similarity to the reported absence of HgCl2 lesions during the acute stages after total cerebral ischemia. This suggests that the cellular components of the BBB participate in a general metabolic inhibition following SAH.
Regional cerebral ischemia by occlusion of the posterior communicating artery and the middle cerebral artery in gerbils
Authors: Yoshimine Toshiki , Yanagihara Takehiko
Published: May 2009

✓ The authors have created an experimental model of regional cerebral ischemia in gerbils that is reproducible and has a low mortality rate. In gerbils, either the posterior communicating artery (PCoA) or the middle cerebral artery (MCA) was occluded, and the distribution of cerebral ischemia from each surgical procedure was compared with that produced by occlusion of the common carotid artery (CCA). In contrast to the widespread cortical and subcortical infarctions seen after occlusion of the CCA, occlusion of the PCoA caused infarction that was restricted to the hippocampus, the piriform cortex, and the posterior part of the thalamus, and occlusion of the MCA resulted in infarction that was restricted to the central part of the cerebral hemisphere and the caudate nucleus and putamen. Intracranial occlusion of the PCoA or MCA in the gerbil resulted in lesions that were reproducible with low mortality rates over a long-term period. Occlusion of the PCoA, MCA, or CCA also produces a model that is suitable for investigation of the postischemic period. A combination of these three experimental models is useful for investigation of regional vulnerability and for the study of regional metabolic differences in cerebral ischemia.
Aneurysms of the posterior inferior cerebellar artery
Authors: Hudgins Rroger J. , Day Arthur L. , Quisling Ronald G. , Rhoton Albert L. , Sypert George W. , Garcia-Bengochea Francisco
Published: May 2009

✓ The clinical and anatomical features of 21 surgically treated saccular aneurysms of the posterior inferior cerebellar artery (PICA) are analyzed. Seventeen of these lesions originated from the PICA-vertebral junction, and four arose from distal PICA branching sites. Twelve lesions arose from the left PICA, nine were right-sided, and all were small (less than 12.5 mm). Most of these aneurysms occurred in females (16 of 21) and presented as classic subarachnoid hemorrhage. The lack of specific focal deficits prevented an accurate pre-angiographic determination of aneurysm location in most instances. Clinically significant vasospasm and aneurysm multiplicity occurred with approximately equal frequency as at other locations.

The angiographic and surgical features of these lesions are determined by the course of the vertebral artery and PICA; that is, they occur at branching sites and at curves in the parent vessel, and point in the direction in which flow would have continued if the curve at the aneurysm's origin had not been present. Aneurysms at the PICA-vertebral junction usually occur at least 1 cm above the foramen magnum level, arise distal to the PICA origin in the angle between the two vessels, and are best approached by a paramedian incision with the patient in the lateral recumbent position. Isolated clipping of the aneurysm neck is essential in this instance, as trapping may compromise vital perforating arteries of the brain stem. More distal (retromedullary) PICA aneurysms are sometimes associated with another vascular anomaly (two cases in this series), and are best handled through a bilateral suboccipital craniectomy. Clipping of the neck is the preferred treatment, but trapping is usually safe, if necessary.
Quantitative analysis of lesion parameters in radiofrequency trigeminal rhizotomy
Authors: Cobb Cully A. , Fung Dennis
Published: May 2009

✓ A series of 144 lesions made during 32 radiofrequency rhizotomies was reviewed. The parameters of each lesion were compared with the sensory change resulting from the lesion. One-half of the lesions resulted in no sensory change, but 16.7% produced numbness in a division not predicted by stimulation. This was a barely detectable sensory change in 6% of lesions and more dense in 10%. The first lesion in a series was particularly likely to result in sensory deficit, and accounted for half of the more dense lesions not predicted by stimulation. When the threshold at which stimulation was perceived was 0.2 volts or less, a lesion was likely to produce numbness, and when it was 0.5 volts or greater, marked sensory loss did not occur. There was no apparent relationship between the likelihood of sensory change and lesion temperature or duration. Analysis of lesion temperature was made more difficult by the use of low temperatures when numbness should be easy to obtain. With careful technique, radiofrequency rhizotomy can be performed with acceptable risk of unpredicted sensory loss. Particular care should be taken during the first lesion in each procedure and when stimulation thresholds are 0.2 volts or less.
Subdural hematoma associated with disseminated intravascular coagulation in patients with advanced cancer
Authors: Furui Tomoo , Ichihara Kaoru , Ikeda Akira , Inao Suguru , Hirai Nagatoshi , Yoshida Jun , Kageyama Naoki
Published: May 2009

✓ Nontraumatic subdural hematoma following disseminated intravascular coagulation (DIC) due to advanced cancer was encountered in four patients. It is suggested that DIC plays an important role in the formation of subdural hematoma in cancer patients.
Developmental defects of the tentorium cerebelli
Authors: Bisaria Krishna Kumar
Published: May 2009

✓ Congenital defects of the tentorium cerebelli were observed in 16 of 90 cadaver cranial cavities examined. These consisted of tentorial dural bands in two, a hole in one case, transverse ridges in eight cases, and an aperture in five cases. In one specimen, the trochlear nerve made a spiral turn around the tentorial band before pursuing its forward course.
Effect of triiodo-L-thyronine on axonal regeneration in the rat spinal cord after acute compression injury
Authors: Tator Charles H. , Rivlin Alex S. , Lewis Anthony J. , Schmoll Beatrice
Published: May 2009

✓ Studies were performed on the effect of triiodo-L-thyronine (T3) on clinical recovery and axonal counts in the pyramidal tract of 56 rats subjected to an acute spinal cord compression injury at T-7. The T3 was given at a daily dose of 5 µg/kg for 4 weeks to 28 rats in the treatment group. The treatment and control animals were tested weekly for clinical recovery, and cord function as determined by the inclined-plane technique. Groups of animals were killed at 4 weeks and 12 weeks, and the axons in the pyramidal tract cephalad and caudad to the injury site were counted in sections prepared with Holmes' silver stain.

There was no difference in clinical recovery between the treatment and control groups. This negative result contrasts with other studies which showed improved recovery of cord-injured animals treated with thyroid hormones. The possible explanations for this discrepancy are discussed. Similarly, there was no difference in the axon counts between the treated and control groups. Thus, T3 did not improve recovery or axonal regeneration in the pyramidal tract of rats after acute spinal cord compression injury. Between 4 and 12 weeks, there was a marked reduction in the cephalad axon counts in the pyramidal tract in both groups, indicating that approximately 50% of the axons in the pyramidal tract had undergone retrograde degeneration or dying back by 12 weeks after this degree of injury. The T3 did not affect the degree of retrograde degeneration.
Anastomosis of the superficial temporal artery to the distal anterior cerebral artery with interposed cephalic vein graft
Authors: Ishii Ryoji , Koike Tetsuo , Takeuchi Shigekazu , Ohsugi Shigeaki , Tanaka Ryuichi , Konno Kimikazu
Published: May 2009

✓ A newly modified cerebral revascularization procedure for ischemia in the territory of the anterior cerebral artery in moyamoya disease is reported. The approach involves interposition of a cephalic vein graft between the superficial temporal artery and the distal anterior cerebral artery (callosomarginal artery) in combination with bilateral routine superficial temporal artery to middle cerebral artery anastomosis. The surgical technique and the possible role of this procedure are discussed.
Unusual computerized tomography appearance of a carotid-cavernous fistula
Authors: Vaghi Maria Antonietta , Savoiardo Mario , Strada Liliana
Published: May 2009

✓ A case of carotid-cavernous fistula characterized by an unusual computerized tomography (CT) pattern is reported. The CT study showed a hyperdense lesion in the right frontoparietal region, and angiography demonstrated an uncommonly large venous network in the same area. After embolization by a detachable balloon technique, these findings gradually resolved. The CT pattern was probably due to the unusually large venous drainage and to the related ischemia of the brain parenchyma.
Spinal subarachnoid hematoma after lumbar puncture causing reversible paraplegia in acute leukemia
Authors: Bladé Joan , Gastón Félix , Montserrat Emili , Marín Pedro , Grañena Albert , Bachs Agustí , Rozman Ciril
Published: May 2009

✓ Subarachnoid hematoma after lumbar puncture is extremely rare, even in patients with thrombocytopenia or other bleeding disorders. The authors report the case of a patient with acute leukemia and thrombocytopenia who developed paraplegia due to a subarachnoid hematoma following lumbar puncture. He recovered after an emergency laminectomy. If a subarachnoid hematoma occurs in a thrombocytopenic patient, prompt surgical treatment, in addition to intensive platelet support, can reverse the severe neurological consequences.
Biphasic occurrence of delayed ischemia after early aneurysm surgery
Authors: Taneda Mamoru , Wakayama Akatsuki , Ozaki Koji , Kataoka Kazuo , Hayakawa Toru , Mogami Heitaro
Published: May 2009

✓ An unusual case of delayed ischemia following rupture of an aneurysm of the left internal carotid artery is reported. Symptoms occurred twice after clipping the aneurysm and removing most of the subarachnoid blood on the left side the day after subarachnoid hemorrhage (SAH). Initial ischemia due to vasospasm occurred on the left side of the brain on the 8th day after SAH and responded favorably to induced hypervolemia. After complete recovery, a second episode due to vasospasm occurred on the 16th day after SAH on the right side of the brain from which the subarachnoid blood had not been removed. This caused a massive lesion and permanent severe neurological deficits. This case suggests that removal of subarachnoid blood may affect the severity and time course of vasospasm, and emphasizes the necessity of extensive removal of subarachnoid blood for prevention of severe delayed ischemic symptoms.
Timing of surgery for intracerebral hematomas due to aneurysm rupture
Authors: Wheelock Brian , Weir Bryce , Watts Reginald , Mohr Gerard , Khan Moe , Hunter Michael , Fewer Derek , Ferguson Gary , Durity Felix , Cochrane Douglas , Benoit Brien
Published: May 2009

✓ Intracerebral hematomas (ICH) from aneurysm rupture are not rare and can now be diagnosed easily and accurately by computerized tomography. The authors have collected 132 such cases from 11 medical centers. Of these patients, 38% died prior to discharge from the hospital. Seventy-eight percent of cases were admitted to the neurosurgical services on Day 0 or 1 after rupture of the aneurysm; of these patients, 15% died without surgery, 28% had surgery and died postoperatively, and 57% were operated on and survived. Mortality rates were increased in patients who were hypertensive, had poor neurological grades, showed evidence of brain herniation, or had larger clots. If the patient lived beyond the first few days and did not have brain herniation, the timing of surgery was not of great consequence, although there was a tendency toward lower morbidity in earlier surgery. This was true despite the fact that earlier operations were carried out on an initially sicker group of patients. Ischemic deterioration attributed to vasospasm occurred in 26% of cases; even when deaths at the acute stage were excluded, it was no more common in patients with early than in those with late surgery. Morbidity and mortality rates were prohibitively high in operations consisting solely of evacuation of ICH without clipping of the aneurysm. Parietal hematomas were particularly dangerous, while those in the temporal lobe were associated with the best outcome. Since it is impossible to predict survival with a high degree of reliability, even when the prognostic indicators are known, the authors recommend that patients with a significant ICH have it removed as soon as possible and that their ruptured aneurysm be clipped at the same time.
Regional cerebral blood flow, sensory evoked potentials, and intracranial pressure in dogs with MCA occlusion by embolization or trapping
Authors: Okada Yoshikazu , Shima Takeshi , Yamamoto Mitsuo , Uozumi Tohru
Published: May 2009

✓ Regional cerebral blood flow (rCBF), sensory evoked potentials (SEP), and intracranial pressure (ICP) were investigated in dogs with focal cerebral ischemia produced by a silicone cylinder embolus in the middle cerebral artery (MCA) trunk as compared to that produced by trapping the same vessel. These variables were measured at intervals of 1 hour for a period of 6 hours after MCA occlusion.

In the embolized animals, rCBF decreased most extensively at the basal ganglia, from a control level of 53.9 ± 3.9 (mean ± SE) to 21.5 ± 2.7 ml/100 gm/min at the 6th hour. Sensory evoked potentials decreased progressively from the resting level of 100% to 53.0% ± 7.2% at the 3rd hour. Intracranial pressure, measured by epidural pressure on the occluded side, increased rapidly during the first 3 hours, from 10.6 ± 0.3 to about 30 cm H2O.

In the animals with trapping, the decreases in rCBF and declines of SEP were significantly less than those in the embolized animals, and no evident brain swelling was observed. This study demonstrates that MCA trunk occlusion by silicone cylinder embolization produces a more marked decrease in deep CBF, with diminution of SEP and increase in ICP, than that produced by trapping.
Local blood flow, oxygen tension, and oxygen consumption in the rat spinal cord
Authors: Hayashi Nariyuki , Green Barth A. , Gonzalez-Carvajal Mayra , Mora Joseph , Veraa Richard P.
Published: May 2009

✓ A reliable and reproducible microelectrode technique provided consistent simultaneous measurements of local spinal cord blood flow (local SCBF), tissue oxygen tension (TO2), and tissue oxygen consumption (TO2C) in the rat. Local SCBF was measured by the hydrogen clearance technique, local TO2 was measured polarographically, and local TO2C was calculated from the declining slope of local TO2 following temporary arrest of local SCBF. Mean local TO2 values varied only slightly between gray and white matter, while local TO2C and SCBF maintained a 3 to 1 ratio between gray and white matter areas. Measurements were also made of these parameters in specific white matter tracts and laminae of Rexed. Local white matter SCBF was relatively homogeneous throughout the ventral, lateral, and dorsal funiculi. Gray matter blood flow was more variable with topography. The highest local SCBF was recorded in areas rich in internuncial neurons. The somatic motor regions had values slightly higher than recorded in sensory regions.
Local blood flow, oxygen tension, and oxygen consumption in the rat spinal cord
Authors: Hayashi Nariyuki , Green Barth A. , Gonzalez-Carvajal Mayra , Mora Joseph , Veraa Richard P.
Published: May 2009

✓ Using a reliable and reproducible microelectrode technique, consistent simultaneous measurements of local spinal cord blood flow (SCBF), tissue oxygen tension, and tissue oxygen consumption were made at cervical, thoracic, and lumbar levels in the rat spinal cord. These observations showed that the metabolic state is maintained constant along the cord, despite significant variations in vasculature. The physiological and anatomical aspects of these findings are discussed.
A new method for measuring cerebrospinal fluid flow in shunts
Authors: Hara Mitsuhiro , Kadowaki Chikafusa , Konishi Yoshifumi , Ogashiwa Motohide , Numoto Mitsuo , Takeuchi Kazuo
Published: May 2009

✓ An implantable device for measurement of cerebrospinal fluid (CSF) flow in a ventriculoperitoneal shunt tube has been developed. The unit is energized by an extracorporeal high-frequency generator (200 KHz), and electrolysis creates bubbles in the shunt tube. Velocity of bubble flow is detected by a pair of ultrasonic Doppler probes placed a certain distance apart on the skin surface and in parallel with the implanted tube. The CSF flow rate is calculated taking into account velocity and tube diameter, and is expressed in ml/min. The unit consists of a coil with a capacitor, a silicon diode to rectify the high frequency, and a Zener diode to regulate maximum output voltage of 20 V. The output is fed to a pair of platinum electrodes placed inside the unit's tunnel through which the CSF flows. These components are molded in epoxy resin and coated with medical-grade silicone rubber. In animal experiments, CSF flow rates ranging from 0.033 to 1.0 ml/min could be measured by this flowmeter. Clinically, CSF flow has been measured to date in several cases. In two cases of communicating hydrocephalus occurring after the onset of cerebrovascular disease, and in which the CSF flow was continuously monitored for 24 hours, the flow rate ranged between 0.05 and 0.78 ml/min. The CSF flow rate fluctuates in a 24-hour period, increasing in the morning, especially between 12 midnight and 6 a.m., which suggests a circadian rhythm.
Effects of intravenous nitroglycerin on the intracranial pressure and volume pressure response
Authors: Ghani Ghaleb A. , Sung Yung Fong , Weinstein Michael S. , Tindall George T. , Fleischer Alan S.
Published: May 2009

✓ Ventricular fluid pressure (VFP) and volume-pressure response were measured during nitroglycerin (NTG) infusion in nine patients anesthetized with N2O and fentanyl. The patients' ventilation was controlled, and PaCO2 was kept at 32 ± 4 mm Hg. When an infusion of 0.01% NTG was given intravenously to decrease the mean blood pressure to 95.1%, 84.7%, and 78.2% of control, the VFP increased from control levels of 9.94 ± 2.14 mm Hg to 12.89 ± 2.25, 15.6 ± 2.85, and 14.43 ± 3.45 mm Hg, respectively. The volume-pressure response showed a significant increase when blood pressure decreased to 84.7% and 78.2% of control. These results suggest that intravenous NTG caused an increase in the intracranial pressure and a decrease in the intracranial compliance.
A quantitative evaluation of suture and tubulization nerve repair techniques
Authors: Gibby Wendell A. , Koerber H. Richard , Horch Kenneth W.
Published: May 2009

✓ The radial and sural nerves in cats were transected and either left unrepaired, repaired with 11-0 epineurial sutures, sutured and treated with topical application of Kenalog, or tubulated with hypoantigenic collagen. One year later the nerves were examined electrophysiologically, using single unit recording techniques, and histologically, by light microscopy. The results indicate that regeneration through the neuroma was comparable in all four groups, but that reinnervation of sensory structures in the skin was most successful in the tubulated nerves.
Meningeal malignant fibrous histiocytoma arising from a thoracolumbar myelomeningocele
Authors: Helle Todd L. , Hanbery John W. , Becker Dennis H.
Published: May 2009

✓ The authors present a case of malignant fibrous histiocytoma (MFH) involving a thoracolumbar myelomeningocele. The patient died of metastases 11 months after diagnosis, in spite of extensive surgery, radiation therapy, and chemotherapy. Meningeal involvement by MFH is very rare; 11 additional cases are reviewed. Glial fibrillary acidic protein staining is critical for proper histological diagnosis, as this tumor can be easily confused with pleomorphic xanthoastrocytoma or glioblastoma involving the meninges.

Malignant degeneration within a myelomeningocele is also very rare. Eight additional cases from the literature are reviewed. Our case is the only one with MFH. Chronic irritation to the unrepaired congenital defect appears to be a key to the development of the malignancy. Prophylactic repair in infancy might prevent the occurrence of malignant degeneration.
Diagnosis and management of pineal tumors
Authors: Jooma Rashid , Kendall Brian E.
Published: May 2009

✓ The management of pineal region tumors remains controversial. Advocates of a conservative approach emphasize the excellent results of radiotherapy, particularly with germinomas, while a number of recent reports have demonstrated the safety of direct surgery. In order to improve treatment planning, attempts have been made to distinguish the various tumor types by computerized tomography (CT) and by the use of markers for germ-cell tumors. This paper reports a study of 35 patients with pineal tumors including two ectopic germinomas. Pretreatment CT was performed in all 35 patients, and human chorionic gonadotropin and alpha-fetoprotein levels were assayed in 11. Histological verification was available for 33 tumors; the other two were characterized by clinical and CT features plus tumor markers. Of the 27 tumor operations, 21 were for a pineal mass and six for ectopic germinoma or metastasis. There was no operative mortality. Morbidity was minimal, and surgery did not increase the incidence of subarachnoid seeding.

Each histological type of tumor has a typical appearance on CT scanning, although, in the individual case, a firm diagnosis is not always possible. However, consideration of CT scans together with the clinical features, cerebrospinal fluid cytology, tumor markers, and (if there is still doubt) response to a small dose of irradiation will generally allow a specific diagnosis with a high degree of probability. In this way, germinomas may be selected for radiotherapy and the tumors less likely to respond may be subjected to primary surgery.
Surgical treatment of brain metastases from lung cancer
Authors: Sundaresan Narayan , Galicich Joseph H. , Beattie Edward J.
Published: May 2009

✓ Thirty-five patients underwent surgical resection of brain metastases from non-oat-cell lung cancer between 1978 and 1981. Twenty-nine patients received postoperative radiation therapy to the brain. Twenty-three patients were male and 12 were female. Intracranial metastases occurred as the initial symptom of malignancy in 14 patients, and at varying periods following treatment of the primary tumor in 21 patients. The primary tumor and involved nodes were treated by definitive surgery in 18 patients, palliative resection and interstitial radiation in 10 patients, and by radiation therapy or chemotherapy alone in seven patients. The overall median survival time was 14 months. Favorable prognostic variables included: 1) absence of local or systemic disease at time of craniotomy (median 23 months survival time); 2) aggressive treatment of the primary tumor (median 18 months survival time); and 3) metachronous onset of brain metastases (median 15 months survival time). These survival data represent a considerable improvement over the historical 6 months median period of survival in such patients.
Phenytoin and postoperative epilepsy
Authors: North J. Brian , Penhall Robert K. , Hanieh Ahmad , Frewin Derek B. , Taylor William B.
Published: May 2009

✓ A double-blind trial of phenytoin therapy following craniotomy was performed to test the hypothesis that phenytoin is effective in reducing postoperative epilepsy. A significant reduction in the frequency of epilepsy was observed in the group receiving the active drug up to the 10th postoperative week. Half of the seizures occurred in the first 2 weeks and two-thirds within 1 month of cranial surgery. High rates of epilepsy were observed after surgery in patients with meningioma, metastasis, aneurysm, and head injury.

Routine prophylaxis with phenytoin (in a dosage of 5 to 6 mg/kg/day) would seem to be indicated, particularly in high-risk patients and, where possible, this treatment should be started 1 week preoperatively. Seizure control is best when therapeutic levels of phenytoin are maintained.
Avoidance of diabetes insipidus in transsphenoidal hypophysectomy
Authors: Leclercq Toussaint A. , Grisoli Francois
Published: May 2009

✓ A modified transsphenoidal microsurgical technique of selective hypophysectomy is described. By preserving the posterior lobe, the pituitary stalk, and the blood supply from the inferior hypophyseal arteries, diabetes insipidus was avoided.
Hemostasis and intracranial surgery
Authors: van der Sande J. Jaap , Veltkamp Jan J. , Bouwhuis-Hoogerwerf Marijke L.
Published: May 2009

✓ Preoperative and postoperative coagulation studies were performed in 25 patients undergoing various intracranial surgical procedures. Coagulation abnormalities, mostly consisting of an increase of fibrin/fibrinogen degradation product concentration, either appeared or increased postoperatively in 18 patients. This incidence of postoperative appearance or increase of coagulation abnormalities is higher than that reported in a comparable study of patients after general surgical procedures, and also higher than that of coagulation abnormalities in a previous study of patients after blunt head injury. Although the coagulation abnormalities after intracranial surgery were usually small, they tended to be larger in patients with more extensive intracranial procedures.