bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlation of the extracellular glutamate concentration with extent of blood flow reduction after subdural hematoma in the rat
Authors: Bullock Ross , Butcher Steve P. , Chen Min-Hsiung , Kendall L. , McCulloch James
Published: May 2009

✓ The excitatory neurotransmitters glutamate and aspartate are an important factor in the causation of ischemic brain damage. The concentration of glutamate and aspartate was serially measured in extracellular fluid using in vivo microdialysis after induction of a subdural hematoma or after a sham operation in the rat. Measurements were made in the cortex underlying the hematoma and in the ipsilateral hippocampus, and these findings were correlated with regional cerebral blood flow (CBF), measured autoradiographically 2 hours after hematoma induction. In the severely ischemic cortex underlying the hematoma (mean CBF < 25 ml/100 gm/min), glutamate and aspartate content increased more than 750% over basal levels. In individual animals the magnitude of glutamate release correlated with the extent of the focal ischemic zone under the hematoma (r = 0.907). Hippocampal glutamate levels rose 339%, yet regional CBF was preserved (114 ml/100 gm/min). This accords with focal hypermetabolism in this model, and may imply a glutamate-mediated “excitotoxic” process after subdural hematoma.
Percutaneous thecoperitoneal shunt for syringomyelia
Authors: Vengsarkar Umesh S. , Panchal Venilal G. , Tripathi Parimal D. , Patkar Sushil V. , Agarwal Alok , Doshi Paresh K. , Kamat Manmohan M.
Published: May 2009

✓ Between January and April, 1990, three consecutive cases of syringomyelia were treated by percutaneous placement of thecoperitoneal shunts. Two of these patients had undergone craniovertebral decompression earlier at other centers and the third was treated primarily by a thecoperitoneal shunt. In each case, the syrinx was associated with Chiari I malformation, although the clinical presentation was due to a myelopathy. All three patients obtained unequivocal benefit from this simple procedure. Postoperative magnetic resonance images showed considerable shrinkage of the cysts corresponding with clinical improvement.
The Dolenc technique for cavernous sinus exploration (cadaveric prosection)
Authors: van Loveren Harry R. , Keller Jeffrey T. , El-Kalliny Magdy , Scodary Daniel J. , Tew John M.
Published: May 2009

✓ This report describes a surgical approach to the cavernous sinus. Based on the work of Parkinson, Dolenc, and other pioneering investigators, a comprehensive surgical approach for the treatment of lesions of the cavernous sinus is distilled and presented in 12 simple steps. The approach to surgical exploration of this region is divided into an extradural and intradural phase, each with six steps. The bony, neural, and/or vascular structures of each step are discussed. These steps may be used in their entirety for total exploration of the cavernous sinus, but also in part for lesions that involve only limited regions of the cavernous sinus. Either by design or circumstance, every intracranial neurosurgeon will eventually be led to the cavernous sinus region, and a clear understanding of cavernous sinus anatomy should be part of their armamentarium.
Treatment of unresectable meningiomas with the antiprogesterone agent mifepristone
Authors: Grunberg Steven M. , Weiss Martin H. , Spitz Irving M. , Ahmadi Jamshid , Sadun Alfredo , Russell Christy A. , Lucci Lois , Stevenson Lani L.
Published: May 2009

✓ The possibility that meningioma growth may be related to female sex hormone levels is suggested by several lines of evidence. Meningiomas are twice as common in women as in men, have been observed to wax and wane with pregnancy, and are positively associated with breast cancer. A physiological explanation for these phenomena is provided by the finding of steroid hormone receptors in meningiomas. However, unlike breast cancer, meningiomas are much more commonly positive for progesterone receptors than for estrogen receptors.

The authors initiated a study on long-term oral therapy of unresectable meningiomas with the antiprogesterone mifepristone (RU486). Fourteen patients received mifepristone in daily doses of 200 mg for periods ranging from 2 to 31+ months (≥ 6 months in 12 patients). Five patients have shown signs of objective response (reduced tumor measurement on computerized tomography scan or magnetic resonance image, or improved visual field examination). Three have also experienced subjective improvement (improved extraocular muscle function or relief from headache). The side effects of long-term mifepristone therapy have been mild. Fatigue was noted in 11 of the 14 patients. Other side effects included hot flashes in five patients, gynecomastia in three, partial alopecia in two, and cessation of menses in two. Long-term therapy with mifepristone is a new therapeutic option that may have efficacy in cases of unresectable benign meningioma.
Benign intrinsic tectal “tumors” in children
Authors: May Paul L. , Blaser Susan I. , Hoffman Harold J. , Humphreys Robin P. , Harwood-Nash Derek C.
Published: May 2009

✓ A specific group of intrinsic dorsal midbrain tumors was identified in six children by computerized tomography (CT) and magnetic resonance (MR) imaging. Each patient presented with raised intracranial pressure as a result of hydrocephalus due to obstruction of the sylvian aqueduct. No patient had brain-stem signs referable to the tectal tumor initially or subsequently. All six children underwent cerebrospinal fluid (CSF) diversionary procedures. The radiological features were consistent and specific, with all patients showing tectal calcification or primary increased attenuation of the tectal plate on CT scans. In addition, lack of contrast enhancement was noted initially in four patients and eventually in all six patients. In all patients MR imaging showed a focal tectal tumor distorting the colicular plate with no cystic component and increased signal intensity on T2-weighted images. There has been no evidence of progression in these six patients in the follow-up period ranging from 8 months to 17 years (8 months and 2½, 4½, 5½, 8, and 17 years). Diversion of CSF has been the only surgical treatment and no patient underwent deep x-ray therapy. Five patients have had normal intellectual development. In contrast to the majority of previously described periaqueductal and tectal tumors, this group of lesions appeared to be truly benign. The authors suggest that patients presenting with these clinical and radiological features may be managed by CSF diversion, serial examination, and MR imaging.
Increased MR signal intensity due to cervical myelopathy
Authors: Matsuda Yasutaka , Miyazaki Kazumi , Tada Kenji , Yasuda Atsushi , Nakayama Tomitaka , Murakami Hitoshi , Matsuo Michimasa
Published: May 2009

✓ The cases of 29 patients with cervical myelopathy, who had been treated by anterior spine fusion, were reviewed. The relationship between pre- and postoperative magnetic resonance (MR) images was investigated with special reference to increased signal intensity in the spinal cord on the T2-weighted images and the relevance of this finding to clinical conditions. Preoperatively, there were areas of increased signal intensity in 12 patients whereas there were no areas of increased signal intensity in the other 17. The lesions were not clearly demonstrated on T1-weighted images. The pre- and postoperative clinical condition of the patients whose preoperative MR images showed areas of increased signal intensity in the spinal cord on T2-weighted images was worse than that of the patients who did not have areas of increased signal intensity. Of the 12 patients with regions of increased signal intensity preoperatively, five showed decreased signal intensity postoperatively compared to the preoperative levels and seven had no change. The postoperative recovery of the five patients who showed decreased signal intensity postoperatively was better than that of the seven patients who exhibited no change. The areas of increased MR signal in the spinal cord might be due to edema, cord gliosis, demyelination, or microcavities.
Suprascapular nerve entrapment
Authors: Callahan James D. , Scully Thomas B. , Shapiro Scott A. , Worth Robert M.
Published: May 2009

✓ Suprascapular nerve entrapment is an acquired neuropathy secondary to compression of the nerve in the bony suprascapular notch. A series of 27 cases, the largest reported to date, is presented and examined as to the best and most appropriate method of diagnosis and treatment. The entity is described in detail as to its origin, anatomy, and pathophysiology.
Nitrogen mustard, vincristine, procarbazine, and prednisone as adjuvant chemotherapy in the treatment of medulloblastoma
Authors: Krischer Jeffrey P. , Ragab Abdelsalem H. , Kun Larry , Kim Tae H. , Laurent John P. , Boyett James M. , Cornell Cornelius J. , Link Michael , Luthy Annette Ridolfi , Camitta Bruce
Published: May 2009

✓ In a randomized postoperative trial, adjuvant post-irradiation chemotherapy, consisting of nitrogen mustard, vincristine, procarbazine, and prednisone (MOPP), was tested versus radiation therapy alone for newly diagnosed medulloblastoma in patients between 1 and 21 years of age. Patients treated with irradiation plus MOPP had a statistically significant increase in overall survival rate at 5 years posttreatment compared to patients treated with radiation therapy alone (74% vs. 56%; p = 0.06, adjusted for race and gender). Although the overall study failed to show a statistically significant advantage for irradiation plus MOPP in event-free survival (p = 0.18), statistical significance was attained in children 5 years of age or older (p = 0.05). More severe hematological toxicities occurred in the group with irradiation plus MOPP; however, this hematotoxicity appeared to be tolerable and acceptable. These results suggest that patients may benefit from combined irradiation and chemotherapy following surgery for medulloblastoma.
Somatosensory function following dorsal root entry zone lesions in patients with neurogenic pain or spasticity
Authors: Jeanmonod Daniel , Sindou Marc
Published: May 2009

✓ The goal of this study was to assess the effects of the dorsal root entry zone (DREZ) lesioning procedure, microsurgical DREZ-otomy (MDT), on spinal cord somatosensory function based on peri- and intraoperative clinical and electrophysiological data. The study was performed prospectively on a series of 20 patients suffering from either chronic neurogenic pain or spasticity. Physiological observations were made of the intraoperative evoked electrospinographic recordings as collected from the surface of the spinal cord.

The MDT procedure produced analgesia or severe hypalgesia, moderate hypesthesia, and only slight deficits in proprioception and cutaneous spatial discrimination on the body segments operated on. These clinical data correlated well with evoked electrospinographic recordings, which showed a moderate effect of MDT on presynaptic compound action potentials recorded from the spinal cord (N11 and N21), a partial or even reversible effect on the cortical postcentral N20 wave, a more marked effect on the postsynaptic dorsal horn waves N13 and N24 related to large primary afferent fibers, and a disappearance of dorsal horn waves related to finer afferents (N2 and possibly N3). These data provide evidence for an acceptably selective action of MDT on spinal cord nociceptive mechanisms, and for a partial, often slight, involvement of the other somatosensory domains. The presence of abnormal evoked electrospinographic waves is discussed in relation to the mechanisms of neurogenic pain and spasticity. The hypothesis of a “retuning” of the dorsal horn as the mode of action of MDT is presented.
Cisterna magna microdialysis of 22Na to evaluate ion transport and cerebrospinal fluid dynamics
Authors: Knuckey Neville W. , Fowler Angela G. , Johanson Conrad E. , Nashold James R. B. , Epstein Mel H.
Published: May 2009

✓ Microdialysis is used in vivo for measuring compounds in brain interstitial fluid. The authors describe another application of this technique to the central nervous system, namely microprobe dialysis in the cisterna magna to study the dynamics of ion transport and cerebrospinal fluid (CSF) formation in the rat. The choroid plexus is the major source of CSF, which is produced by active transport of Na from blood into the cerebral ventricles. Formation of CSF is directly proportional to the blood-to-CSF transport of Na. By injecting 22Na into the systemic circulation and quantifying its movement into CSF by microdialysis, one can reliably estimate alterations in the rate of CSF formation. The sensitivity of this system was determined by administering acetazolamide, a standard inhibitor of CSF production. Because acetazolamide is known to decrease CSF formation by 40% to 50%, the cisternal microdialysis system in animals treated with this drug should detect a corresponding decrease in the amount of 22Na dialyzed. This hypothesis is supported by the 22Na uptake curves for control versus treated animals: that is, by the acetazolamide-induced average diminution of about 45% in both the rate and extent of tracer accession to dialysate. Bumetanide, a loop diuretic, reduced by 30% the 22Na entry into dialysate. Microprobe dialysis of fluid in the cisterna magna is thus a minimally invasive and economical method for evaluating effects of drugs and hormones on the choroid plexus-CSF system.
Magnetic resonance imaging of vertebrobasilar ectasia in tic convulsif
Authors: Harsh Griffith R. , Wilson Charles B. , Hieshima Grant B. , Dillon William P.
Published: May 2009

✓ A patient with trigeminal neuralgia and hemifacial spasm was evaluated using multiplanar magnetic resonance (MR) imaging with gadolinium enhancement. Preoperative images demonstrated massively ectatic vertebral and basilar arteries and their distortion of the brain stem and the trigeminal and facial nerves. Surgical manipulation included selective trigeminal rhizotomy, cushioning of the residual nerve at the point of maximal distortion by the underlying basilar artery, and microvascular decompression of the seventh nerve from the anterior inferior cerebellar artery which was being pushed dorsomedially by the vertebral artery. Postoperatively, the patient had neither trigeminal neuralgia nor facial spasm. Gadolinium-enhanced MR imaging not only excludes other etiologies such as tumor or arteriovenous malformation, but also demonstrates cranial nerve compression by ectatic vertebral and basilar arteries. The choice of preoperative imaging modality is discussed and the literature concerning the etiology of tic convulsif is reviewed.
A new surgical approach to subcortical lesions: balloon inflation and cortical gluing
Authors: Hirsch Jean-François , Sainte-Rose Christian
Published: May 2009

✓ A cortical incision performed with inflation of a balloon to create a channel has been used in an approach to deep lesions with minimal damage to cerebral tissue. The balloon is slipped over a blunt needle and, once in place, is inflated through the needle. Postoperative sealing of the incision with fibrin glue avoids the subdural collection of cerebrospinal fluid such as is sometimes observed when the ventricle is opened during surgery.
Cardiac performance indices during hypervolemic therapy for cerebral vasospasm
Authors: Levy Michael L. , Giannotta Steven L.
Published: May 2009

✓ The effect of hypervolemic preload enhancement on cardiac performance was systematically analyzed in nine patients following aneurysmal subarachnoid hemorrhage. The patients ranged in age from 34 to 63 years, and none had a history of cardiac disease. Each patient underwent placement of a flow-directed balloon-tipped catheter and the following measurements were taken during hypervolemic therapy: pulmonary artery wedge pressure (PAWP), central venous pressure (CVP), cardiac index (CI), stroke volume index (SVI), and left ventricular stroke work index (LVSWI). After baseline measurements were recorded, hetastarch or plasmanate was infused intravenously at 300 cc/hr. Thermal output determination and pressures were measured every 15 minutes. The PAWP did not correlate in a statistically significant fashion with the CVP in the ranges recorded; however, a statistically significant correlation did exist between PAWP increases and increases in CI, SVI, and LVSWI (p < 0.01). There was no statistical correlation between PAWP increases above 14 mm Hg and improvement in cardiac performance as evidenced by CI, SVI, and LVSWI measurements. It is concluded that CVP is an unreliable index of cardiac performance during hypervolemic therapy and that, in previously healthy individuals, a PAWP of 14 mm Hg is associated with maximum cardiac performance.
Cavernous malformations of the brain stem
Authors: Zimmerman Richard S. , Spetzler Robert F. , Lee K. Stuart , Zabramski Joseph M. , Hargraves Ronald W.
Published: May 2009

✓ Once they become symptomatic, cavernous malformations of the brain stem appear to cause progressive morbidity from repetitive hemorrhage, and can even be fatal. Twenty-four patients with long-tract and/or
cranial nerve findings from their cavernous malformations of the brain stem were seen for initial evaluation or surgical consultation and thereafter received either surgical or continued conservative treatment. The decision to operate was based on the proximity of the cavernous malformation to the pial surface of the brain stem, the patient's neurological status, and the number of symptomatic episodes. Sixteen patients were treated by definitive surgery directed at excision of their malformation. In four patients, associated venous malformations influenced the surgical approach and their recognition avoided the risk of inappropriate excision of the venous malformation. Although some of the 16 patients had transient, immediate, postoperative worsening of their neurological deficits, the outcome of all except one was the same or improved. Only one patient developed recurrent symptoms: a new deficit 2½ years after surgery required reoperation after regrowth of the cavernous malformation. She has been neurologically stable since the second surgery. One patient died 6 months postoperatively from a shunt infection and sepsis. The eight conservatively treated patients are followed with annual magnetic resonance imaging studies. One has a dramatic associated venous malformation. Seven patients have either minor intermittent or no symptoms, and the eighth died from a hemorrhage 1 year after his initial presentation.

Based on these results, surgical extirpation of symptomatic cavernous malformations of the brain stem appears to be the treatment of choice when a patient is symptomatic, the lesion is located superficially, and an operative approach can spare eloquent tissue. When cavernous malformations of the brain stem are completely excised, cure appears permanent.
Stereotactic management of colloid cysts: factors predicting success
Authors: Kondziolka Douglas , Lunsford L. Dade
Published: May 2009

✓ Stereotactic aspiration is a valuable surgical alternative for colloid cysts when used alone or in conjunction with microsurgical resection. Since 1981, the authors have performed computerized tomography (CT)-guided stereotactic aspiration as the initial procedure in 22 patients with colloid cysts; stereotactic aspiration alone was successful in 11 patients (50%). Of the 11 patients in whom aspiration failed, stereotactic endoscopic resection was attempted in three and was successful in one. Seven patients required a craniotomy and microsurgical removal of the cyst performed via a transcortical approach.

The preoperative CT appearance in eight cases of a hypodense or isodense cyst correlated favorably with successful aspiration of the cyst in six patients. A hyperdense appearance on the preoperative CT scan in 14 cases was associated with subtotal aspiration in 13 patients; five required craniotomy for removal. Preoperative magnetic resonance (MR) imaging in eight patients provided excellent anatomical definition of the cyst and its relationship to other structures of the third ventricle, but it was not possible to correlate successful aspiration with cyst appearance on MR images with short or long relaxation time sequences. The authors' 9-year experience suggests that preoperative CT studies accurately determine size, predict viscosity, and help to define a group of colloid cyst patients for whom stereotactic cyst aspiration will likely be successful. Unsuccessful stereotactic aspiration was related to two features: the high viscosity of the intracystic colloid material (nine patients), or deviation of the cyst away from the aspiration needle due to small cyst volume (two patients). Because of its simplicity and low risk, stereotactic surgery can be offered to selected patients as the initial procedure of choice. Craniotomy can be reserved for those whose imaging studies predict failure or for those whose cyst cannot be aspirated.
Relationship between the timing of aneurysm surgery and the development of delayed cerebral ischemia
Authors: Solomon Robert A. , Onesti Stephen T. , Klebanoff Louise
Published: May 2009

✓ A consecutive series of 145 patients with acute aneurysmal subarachnoid hemorrhage (SAH) were operated on within 7 days of SAH and were prospectively evaluated over a 4-year period to determine if the timing of aneurysm surgery influenced the development of delayed cerebral ischemia. All patients were managed with a standardized policy of urgent surgical clipping and treatment with aggressive prophylactic postoperative volume expansion. Patients with delayed ischemic symptoms were additionally treated with induced hypertension.

Forty-nine patients underwent surgery on Day 0 or 1 (Group 1) post-SAH, 60 patients on Day 2 or 3 (Group 2), and 36 patients on Days 4 through 7 (Group 3). Postoperative delayed cerebral ischemia developed in 16% of (Group 1) patients, in 22% of Group 2 patients, and in 28% of Group 3 patients. Cerebral infarction resulting from delayed cerebral ischemia developed in only 4% of Group 1 patients, 10% of Group 2 patients, and 11 % of Group 3 patients. A bad clinical outcome as a result of delayed cerebral ischemia occurred in one Group 1 patient (2%), two Group 2 patients (3%), and one Group 3 patient (3%). Preoperative grade was not significantly correlated with the incidence or severity of delayed cerebral ischemia at any time interval except that patients in modified Hunt and Hess Grade I or II who underwent surgery on Day 0 or 1 after SAH had no strokes or bad outcomes from delayed cerebral ischemia. This study demonstrates that there is no rationale for delaying aneurysm surgery based on the time interval between SAH and patient evaluation.
Postoperative deficits and functional recovery following removal of tumors involving the dominant hemisphere supplementary motor area
Authors: Rostomily Robert C. , Berger Mitchel S. , Ojemann George A. , Lettich Ettore
Published: May 2009

✓ The supplementary motor area (SMA) is a region located within each cerebral hemisphere at the posterior mesial border of the frontal lobe adjacent to the falx. The functional significance of this area has been somewhat unclear, and information regarding its influence on motor output has largely been based on evoked responses to direct stimulation in primates and humans. In this series of patients with primary and metastatic tumors involving the dominant hemisphere SMA, a distinct pattern of postoperative deficits and recovery has emerged which emphasizes the role of this critical area in the initiation of motor activity, including speech. Based upon this analysis, ablation of this region after first identifying the primary motor cortex may be accomplished without risk of permanent loss of motor activity or speech function, despite the initial severe deficits.
Primary angiosarcoma of the central nervous system
Authors: Mena Hernando , Ribas Jorge L. , Enzinger Franz M. , Parisi Joseph E.
Published: May 2009

✓ Angiosarcoma arising in the central or peripheral nervous system has rarely been reported. Eight patients with primary angiosarcoma of the central nervous system are described here; these included five males and three females ranging in age from 2 weeks to 72 years (mean 38 years). Of the eight neoplasms, six were located in the cerebral hemispheres and one was in the meninges; the site was unknown in the other. All patients underwent surgical resection. Five of the eight patients died, four within 4 months after surgery and one after 30 months. Two of the remaining three patients were 17 and 27 years old at the time of diagnosis and were alive at follow-up review 39 and 102 months after surgery, respectively. One patient was lost to follow-up monitoring.

Microscopically, all eight tumors demonstrated a well-differentiated pattern with irregular vascular channels and intraluminal papillae; in addition, four showed poorly differentiated solid areas. Immunohistochemical staining of neoplastic cells to factor VIII-related antigen and Ulex europaeus agglutinin I was performed in five tumors and was focally positive in four. No correlation could be shown between the histological features and the growth and biological behavior of the tumors.
Altered reactivity of hemolysate-treated cultured smooth-muscle cells from rabbit basilar artery determined by digital imaging microscopy
Authors: Takanashi Yoshihiro , Fujitsu Kazuhiko , Fujii Satoshi , Kuwabara Takeo
Published: May 2009

✓ During culture, smooth-muscle cells obtained from rabbit basilar arteries were examined for contractile activity by means of differential interference microscopy with a video analysis system (digital imaging microscopy system). This system proved useful for observing the contraction and ultrastructural changes of the living cells. Hemolysate-treated cells showed augmented responses to 5-hydroxytryptamine and leukotriene C4, but not to KCl. This augmented response diminished gradually during the culture period. Both a phospholipase C blocking agent, 2-nitro-4-carboxyphenyl-n,n-diphenylcarbamate (NCDC), and a myosin light chain kinase blocking agent, 1-(5-chloronaphthalenesulfonyl)-1 H-hexahydro-1,4-diazepine (ML-9), suppressed this augmented response. Protein kinase C activity of the cells, as measured by Western blot analysis, did not increase during the period of culture with hemolysate. The results obtained suggest that hemolysate had the following effects on the cells: 1) acute but gradual contraction of the cells; 2) augmentation of cellular responses to vasoactive agents; and 3) progressive contraction and morphological alteration of the cells. Possible mechanisms by which hemolysate exerts these effects are discussed, taking into consideration the interrelationship between these effects.
Differences in critical cerebral blood flow with age in swine
Authors: Harada Jun , Takaku Akira , Endo Shunro , Kuwayama Naoya , Fukuda Osamu
Published: May 2009

✓ Normal cerebral blood flow (CBF), critical CBF at a flat reading of the electroencephalogram (EEG), and reversibility of the flat EEG after reperfusion were investigated in a total of 59 pigs, including seven newborns (1 to 3 days of age), 38 juveniles (1 month old), and 14 adults (7 months old). The CBF was determined by the hydrogen clearance method; the EEG was recorded continuously and a power spectrum analysis was performed. Cerebral ischemia was produced by occlusion of both common carotid arteries and induction of hypotension (approximately 50 mm Hg). The flat EEG reversibility was investigated for 3 hours after reperfusion. As parameters of brain development, the neuronal density and the time at which the S-100 protein appeared in the brain were examined.

Normal CBF was highest in neonatal pigs and decreased with age. The critical CBF at a flat EEG was lowest in newborn pigs and was elevated with development of the brain. Tolerance against cerebral ischemia was greatest in newborn pigs.
Intracranial neurenteric cysts
Authors: Malcolm George P. , Symon Lindsay , Kendall Brian , Pires Manuel
Published: May 2009

✓ Two cases of intracranial neurenteric cysts are reported and the literature is reviewed. Neurenteric cysts are rare congenital lesions that tend to occur in the spinal intradural space. An intracranial location is exceptional.
Hemifacial spasm in an infant due to fourth ventricular ganglioglioma
Authors: Bills Douglas C. , Hanieh Ahmed
Published: May 2009

✓ The case of an infant is reported in which hemifacial spasm due to a ganglioglioma of the fourth ventricle was relieved by surgery. Previously described causes of hemifacial spasm are summarized, and the relevance of this case to theories on the pathogenesis of the condition is discussed.
Index for optimum ventricular catheter length
Authors: Keskil Semih İ. , Çeviker Necdet , Baykaner Kemali , Alp Hizir
Published: May 2009

✓ The optimum length of a ventricular catheter to be placed in a particular patient may be difficult to determine when either intraoperative ultrasound is not available or considerable time has elapsed between the diagnostic computerized tomography scan and the operation. An index for estimating ventricular length based on the head circumference of the individual is described. This method was tested clinically and proved to be successful.
The Johns Hopkins Hospital
Authors: Long Donlin M.
Published: May 2009

The role of The Johns Hopkins University as an innovative school with a basic mission of scientific research is discussed. Its principle that research is best performed by faculty and students at a graduate level gave birth to the revolutionary concept of a research university. Against this background, the hospital and later the medical school were founded. The innovations that emerged from this medical education structure are touched on.
Effect of intrathecal fibrinolytic therapy on clot lysis and vasospasm in patients with aneurysmal subarachnoid hemorrhage
Authors: Öhman Juha , Servo Antti , Heiskanen Olli
Published: May 2009

✓ A prospective series of 30 patients with a single, angiographically verified aneurysmal subarachnoid hemorrhage (SAH) was studied for the effect of intrathecal thrombolytic therapy with recombinant tissue plasminogen activator (rt-PA) on outcome, angiographic vasospasm, and computerized tomography (CT) findings after surgery. The patients included fulfilled the following criteria: operation was performed by Day 3 after the hemorrhage, CT showed only blood in the basal cisterns, and the patient had a single aneurysm or multiple aneurysms that could be treated surgically at the same operation. The patients were divided into groups of 10, with patients receiving 3, 10, or 13 mg of rt-PA in a single intracisternal injection at the end of the operation. There were no differences between the treatment groups in overall outcome. One patient from the 3-mg rt-PA group developed a postoperative intracerebral hemorrhage, and one patient from the 10-mg rt-PA group had a postoperative epidural hematoma. There was one death in the 13-mg rt-PA group that was caused by inclusion of a segment of pericallosal artery in the clip. In all treatment groups a reduction was observed in the amount of blood seen on the postoperative CT scans compared to the preoperative CT scans. The reduction in SAH grade between the 10-mg and 13-mg rt-PA groups was significant (p < 0.05). The difference in the severity of angiographic vasospasm between the 3-mg and 13-mg rt-PA groups was also significant (p < 0.05).
Endovascular treatment of intracerebral arteriovenous malformations: experience in 49 cases
Authors: Fournier Dominique , TerBrugge Karel G. , Willinsky Robert , Lasjaunias Pierre , Montanera Walter
Published: May 2009

✓ The authors report the results of treatment in 49 consecutive patients with brain arteriovenous malformations (AVM's) who underwent therapeutic embolization with liquid adhesive agents between 1984 and 1988 at the Toronto Western Hospital. Thirty-three patients had no other treatment and were followed up with angiography at 2 years and clinically from 2 to 6 years. Of the other 16 patients, 10 had adjunctive radiosurgery and six underwent surgical resection following embolization. Seven (14%) of the 49 patients had a morphological cure effected by embolization as evidenced on their 2-year follow-up angiograms; these have remained clinically stable. Twelve patients developed neurological deficits after embolization; eight (16% of the series) were transient and four (8%) were permanent. Two patients (4%) had a delayed hemorrhage after incomplete obliteration of their malformations. Endovascular treatment resulted in clinical improvement in 15 (33%) of the other 46 patients. None of the patients who initially presented with hemorrhage had a rebleed following embolization. It is concluded that endovascular treatment with liquid embolic material can be an integral part of the multidisciplinary treatment protocol for patients with brain AVM's.
Prediction tree for severely head-injured patients
Authors: Choi Sung C. , Muizelaar Jan P. , Barnes Thomas Y. , Marmarou Anthony , Brooks Danny M. , Young Harold F.
Published: May 2009

✓ Prediction tree techniques are employed in the analysis of data from 555 patients admitted to the Medical College of Virginia hospitals with severe head injuries. Twenty-three prognostic indicators are examined to predict the distribution of 12-month outcomes among the five Glasgow Outcome Scale categories. A tree diagram, illustrating the prognostic pattern, provides critical threshold levels that split the patients into subgroups with varying degrees of risk. It is a visually useful way to look at the prognosis of head-injured patients. In previous analyses addressing this prediction problem, the same set of prognostic factors (age, motor score, and pupillary response) was used for all patients. These approaches might be considered inflexible because more informative prediction may be achieved by somewhat different combinations of factors for different patients. Tree analysis reveals that the pattern of important prognostic factors differs among various patient subgroups, although the three previously mentioned factors are still of primary importance. For example, it is noted that information concerning intracerebral lesions is useful in predicting outcome for certain patients. The overall predictive accuracy of the tree technique for these data is 77.7%, which is somewhat higher than that obtained via standard prediction methods. The predictive accuracy is highest among patients who have a good recovery or die; it is lower for patients having intermediate outcomes.
Head-injured patients who talk and deteriorate into coma
Authors: Lobato Ramiro D. , Rivas Juan J. , Gomez Pedro A. , Castañeda Mario , Cañizal José M. , Sarabia Rosario , Cabrera Antonio , Muñoz Maria J.
Published: May 2009

✓ Of 838 patients with severe head injuries admitted since the introduction of computerized tomography, 211 (25.1%) talked at some time between trauma and subsequent deterioration into coma. Of these 211 patients, 89 (42.2%) had brain contusion/hematoma, 46 (21.8%) an epidural hematoma, 35 (16.6%) a subdural hematoma, and 41 (19.4%) did not show focal mass lesions. Thus, four of every five patients who deteriorated into coma after suffering an apparently nonsevere head injury had a mass lesion potentially requiring surgery; the mass was intracerebral in 52.3% of the cases and extracerebral in 47.6%. Patients aged 20 years or less had a 39% chance of having a nonfocal mass lesion (diffuse brain damage), a 29% chance of having an epidural hematoma, and a 32% chance of having an intradural mass lesion; patients over 40 years had only a 3% chance of having a nonfocal mass lesion, an 18% chance of having an epidural hematoma, and a 79% chance of having a intradural mass lesion.

Sixty-eight (32.2%) patients died and 143 (67.8%) survived. The following were independent outcome predictors (in order of significance): Glasgow Coma Scale score following deterioration into coma, the highest intracranial pressure during the patient's course, the degree of midline shift, the type of intracranial lesion, and the age of the patient. In contrast, the mechanism of injury, the verbal Glasgow Coma Scale score during the lucid interval, and the length of time until deterioration or until operative intervention did not influence the final result.
Supratentorial dermoid cysts
Authors: Lunardi Pierpaolo , Missori Paolo
Published: May 2009

✓ Supratentorial dermoid cysts are rare lesions. In eight cases presented here, the lack of recurrence after subtotal removal of the capsule and the good long-term prognosis are emphasized. This finding is in agreement with the literature. The frequent relationship of these lesions with the cavernous sinus suggests a vascular genesis in the development of intracranial dermoid cysts.
Application of the 1-µsec pulsed-dye laser to the treatment of experimental cerebral vasospasm
Authors: Teramura Atsushi , Macfarlane Robert , Owen Christopher J. , Torre Ralph de la , Gregory Kenton W. , Birngruber Reginald , Parrish John A. , Peterson John W. , Zervas Nicholas T.
Published: May 2009

✓ Laser energy of 480 nm was applied in 1-µsec pulses varying between 2.2 and 10 mJ to in vitro and in vivo models of cerebral vasospasm. First, the pulsed-dye laser was applied intravascularly via a 320-µm fiber to basilar artery segments from six dogs. The segments were mounted in a vessel-perfusion apparatus and constricted to, on average, 70% of resting diameter by superfusion with dog hemolysate. Immediate increase in basilar artery diameter occurred to a mean of 83% of control. In a second model, the basilar artery was exposed transclivally in the rabbit. In three normal animals, superfusion of the artery with rabbit hemolysate resulted in a reduction of mean vessel diameter to 81% of control. Following extravascular application of the laser, vessels returned to an average of 106% of the resting state. In six rabbits, the basilar artery was constricted by two intracisternal injections of autologous blood, 3 days apart. Two to 4 days after the second injection, the basilar artery was exposed. Extravascular laser treatment from a quartz fiber placed perpendicular to the vessel adventitia resulted in an immediate 53% average increase in caliber to an estimated 107% of control. No reconstriction was observed over a period of up to 5 hours. Morphologically, damage to the arterial wall was slight. This preliminary investigation suggests that the 1-µsec pulsed-dye laser may be of benefit in the treatment of cerebral vasospasm.
Dorello's canal: a microanatomical study
Authors: Umansky Felix , Elidan Josef , Valarezo Alberto
Published: May 2009

✓ The microsurgical anatomy of Dorello's canal has been studied in 20 specimens obtained from 10 cadaver heads fixed in formalin. The bow-shaped canal through which courses the abducens nerve before reaching the cavernous sinus is located inside a venous confluence which occupies the space between the dural leaves of the petroclival area. The petrosphenoidal ligament (Gruber's ligament), which forms the posteromedial wall of the canal, appears as a fibrous trabecula surrounded by venous blood. Canal measurements were performed and its anatomical relationship with the sixth cranial nerve is described. Angulations of variable degrees were observed in the course of the nerve inside and outside the canal. The influence of this relatively tortuous course of the abducens nerve upon its vulnerability in some pathological conditions is discussed.
Microvascular anatomy of foramen caecum medullae oblongatae
Authors: Mahmood Asim , Dujovny Manuel , Torche Maximo , Dragovic Ljubisa , Ausman James I.
Published: May 2009

✓ The foramen caecum (FC) is a triangular-shaped fossa situated in the midline on the base of the brain stem, at the pontomedullary junction. Although this area is known to have a very high concentration of brainstem perforating vessels, its microvascular anatomy has not been studied in detail. The purpose of this study was to detail the microvasculature of this territory. Twenty unfixed brains were injected with silicone rubber solution and dissected under a microscope equipped with a camera. The origin, course, outer diameter, and branching pattern of the perforators were examined.

The total number of perforators found in the 20 brains was 287, with an average (± standard deviation) of 14.35 ± 1.24 perforators per brain (range seven to 28). Their origin was as follows: right vertebral artery in 52 perforators (18.11%); left vertebral artery in 35 (12.19%); basilar artery below the anterior inferior cerebellar artery (AICA) in 139 (48.43%); basilar artery above the AICA in 46 (16.02%); AICA in 10 (3.48%); and anterior spinal artery in five (1.74%). Most of the perforators arose as sub-branches of larger trunks; their average outer diameter was 0.16 ± 0.006 mm while that of trunks was 0.35 ± 0.02 mm.

These anatomical data are important for those wishing 1) to study the pathophysiology of vascular insults to this area caused by atheromas, thrombi, and emboli; 2) to plan vertebrobasilar aneurysm surgery; 3) to plan surgery for vertebrobasilar insufficiency; and 4) to study foramen magnum neoplasms.
Clipping of an aneurysm 20 years after encasement with methyl methacrylate
Authors: Ogilvy Christopher S. , Poletti Charles E.
Published: May 2009

✓ A variety of agents have been used to coat aneurysms as an alternative to clipping. These agents were employed more frequently prior to the routine use of the operating microscope and the presently available variety of aneurysm clips. One such coating agent is methyl methacrylate. This report describes a patient with an anterior communicating aneurysm that rebled 20 years after being encased in methyl methacrylate. At operation, the pulsating aneurysm had eroded the adjacent layer of methyl methacrylate, creating a small intervening space. This space allowed removal under the microscope (with a high-speed air drill and a diamond bit) of the methyl methacrylate from the anterior cerebral arteries and aneurysm, exposing it for definitive clip placement. The feasibility of clipping encased aneurysms is discussed.
Symptomatic xanthogranuloma of choroid plexus with unilateral hydrocephalus
Authors: Brück Wolfgang , Sander Ulrich , Blanckenberg Peter , Friede Reinhard L.
Published: May 2009

✓ Xanthogranulomas involving the choroid plexus of the lateral ventricles are generally asymptomatic lesions. The case is reported of a 50-year-old man in whom a xanthogranuloma of the choroid plexus had occluded the left trigone, causing unilateral hydrocephalus of the left temporal horn and neurological symptoms. A review of the literature shows that xanthogranulomas of the glomus of the lateral ventricles differ from the xanthomatous cystic lesions of the third ventricle, which are probably akin to colloid cysts.
Resin sealant: a new method of methyl methacrylate cranioplasty
Authors: Yanai Akira
Published: May 2009

✓ A new method of cranioplasty is described. The skull defect is exposed and multiple angled holes are drilled in the outer cortical bone around the defect. A resin plate is conventionally molded to fit the defect. After the resin plate is positioned in the skull defect, newly prepared viscous resin putty is injected into the holes around the defect. The viscous resin comes into contact with the margin of resin plate and, when it hardens, a monoblock casting of resin is formed. The resin plate is sealed to the bone. This technique has the main advantage of strength and good cosmetic appearance.
Identification of the proximal neck of giant paraclinoidal aneurysms
Authors: Mikabe Toshio , Tomita Shin , Watanabe Saburo , Oya Shigeru , Yuzurihara Masahito , Mochida Hidetoshi
Published: May 2009

✓ Introduction of a double-lumen Swan-Ganz balloon catheter into the parent artery facilitated precise identification of the proximal neck in two giant paraclinoidal aneurysms. Reduction of the flow rate as low as possible and positioning of the patient's head were the most important factors in this procedure.
Intracranial aneurysms in sickle-cell anemia: clinical features and pathogenesis
Authors: Oyesiku Nelson M. , Barrow Daniel L. , Eckman James R. , Tindall Suzie C. , Colohan Austin R. T.
Published: May 2009

✓ Intracranial aneurysms are an unusual complication of sickle-cell anemia; only 15 patients have been described in the world literature. An additional 15 patients with sickle-cell anemia and subarachnoid hemorrhage (SAH) from ruptured intracranial aneurysms are presented. There was a high incidence of multiple aneurysms (60%); some of which were in unusual locations. The clinical and pathological features of this series of patients have provided a paradigm for acquired aneurysm formation that may be applicable to other intracranial aneurysms. Thirteen patients underwent craniotomy and clip ligation; the perioperative management of these patients is discussed. Of these 13, eight had a good recovery, three were left with moderate disability, one patient died of surgical complications, and one died of complications related to sickle-cell anemia. Two of the 15 patients died of SAH. The authors propose that endothelial injury from the abnormal adherence of sickle erythrocytes to the endothelium is the initiating event in arterial wall injury. Subsequently, there is fragmentation of the internal elastic lamina and degeneration of the smooth-muscle layer. Hemodynamic stress at these loci of arterial wall damage results in aneurysm formation. This hypothesis also explains other cerebrovascular manifestations of sickle-cell anemia, namely vaso-occlusive disease and hemorrhage without aneurysm formation. Pathological material from this series and data from the literature are presented to support this hypothesis.
Surgical treatment of limbic epilepsy associated with extrahippocampal lesions: the problem of dual pathology
Authors: Lévesque Michel F. , Nakasato Nobukazu , Vinters Harry V. , Babb Thomas L.
Published: May 2009

✓ The authors present their review of 178 patients who underwent en bloc temporal lobectomies as surgical treatment for intractable epilepsy. Hippocampal cell density was quantitatively analyzed and the histology of the anterior temporal lobe was reviewed. Fifty-four patients (30.3%) had evidence of extrahippocampal lesions in addition to neuronal cell loss within the hippocampus (the dual pathology group). The pattern of cell loss was analyzed in the remaining 124 cases (69.7%) with no extrahippocampal pathology, and compared with that of the dual pathology group and a control group of four nonepileptic patients.

Hippocampal cell loss was found in almost all epileptic patients compared to the control group. Severe cell loss greater than 30% of control values was found in 88.7% of patients without extrahippocampal lesions, but in only 51.8% of patients with dual pathology. The difference between these two groups was statistically significant (p < 0.001). In the dual pathology group, lesions of different pathology had a significant relationship with the degree of hippocampal cell loss: all 12 patients with glioma had mild cell loss, whereas all 13 patients with heterotopia were associated with severe cell loss. Severity of hippocampal cell loss was also analyzed in relation to seizure history: a prior severe head injury was associated with severe cell loss. Other factors such as seizure duration, secondary generalization, or family history of seizures were not associated with hippocampal damage. Dual pathology may produce a combination of neocortical and temporolimbic epilepsies that warrants a precise definition of the true epileptogenic area prior to surgical treatment.