bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surgical management of brainstem hemangioblastomas in patients with von Hippel—Lindau disease
Authors: Weil Robert J. , Lonser Russell R. , Devroom Hetty L. , Wanebo John E. , Oldfield Edward H. 
Published: May 2009

Object. Hemangioblastomas of the brainstem constitute 5 to 10% of central nervous system (CNS) tumors in patients with von Hippel—Lindau (VHL) disease. At present, optimal management of brainstem hemangioblastomas associated with VHL disease is incompletely defined. In an attempt to clarify some of the uncertainty about the operative treatment of these lesions and its outcome, the authors reviewed all cases of VHL disease in which resection of brainstem hemangioblastomas was performed at the National Institutes of Health during a 10-year period.
Methods. Twelve consecutive patients with VHL disease (six male and six female patients [mean age 31.7 ± 9 years; range 15–46 years]) who underwent 13 operations to remove 17 brainstem hemangioblastomas were included in this study (mean follow-up period, 88.4 ± 37.4 months; range 37–144 months). Serial examinations, hospital charts, magnetic resonance images, and operative records were reviewed. To evaluate clinical course, clinical grades were assigned to each patient before and after surgery.
Preoperative neurological function was the best predictor of long-term outcome. In addition, patients who underwent CNS surgeries for hemangioblastomas were more likely to improve or to remain neurologically stable. Tumor or cyst size, the presence of a cyst, or the location of the tumor (intramedullary, extramedullary, or mixed; posterior medullary, obex, or lateral) did not affect outcome. No patient was neurologically worse after brainstem surgery. At long-term follow-up review (mean 88.4 months), only one patient had declined neurologically and this was due to the cumulative neurological effects caused by eight additional hemangioblastomas of the spinal cord and their surgical treatment.
Conclusions. Brainstem hemangioblastomas in patients with VHL disease can be removed safely; they generally should be resected when they become symptomatic or when the tumor has reached a size such that further growth will increase the risks associated with surgery, or in the presence of an enlarging cyst. Magnetic resonance imaging is usually sufficient for preoperative evaluation and presurgical embolization is unnecessary. The goal of surgery is complete resection of the lesion before the patient experiences a disabling neurological deficit.
Progressive and extensive dopaminergic degeneration induced by convection-enhanced delivery of 6-hydroxydopamine into the rat striatum: a novel rodent model of Parkinson disease
Authors: Oiwa Yoshitsugu , Sanchez-Pernaute Rosario , Harvey-White Judith , Bankiewicz Krys S. 
Published: May 2009

Object. A striatal dopamine lesion induces progressive nigral degeneration in rodents; however, intrastriatal injection of 6-hydroxydopamine (6-OHDA) causes only limited lesions due to spontaneous regeneration of the neurons that survive. To make an extensive lesion, the authors used a convection-enhanced delivery (CED) method for intrastriatal infusion of 6-OHDA and evaluated the animals for a model of Parkinson disease (PD).
Methods. Different doses of 6-OHDA were infused into the unilateral striatum in rats by using the CED method. The dopaminergic neuronal degeneration was evaluated based on morphological, biochemical, and behavioral measurements until 8 weeks postlesion.
Due to the wide distribution of the drug, CED of 20 µg of 6-OHDA into the striatum was sufficient to obtain a progressive and extensive nigrostriatal lesion as defined by morphological (> 80% cell loss in the substantia nigra [SN]) and biochemical (> 95% decrease in striatal dopamine) criteria. The extent of the lesion manifested as a stable turning behavior with amphetamine (> 6 turns/minute) and apomorphine (> 4 turns/minute). It also appeared that at 1 week postlesion the apoptotic markers were maximal in neurons of the SN.
Conclusions. A rat model of PD with a progressive and extensive dopamine lesion was successfully made by intrastriatal CED of 6-OHDA. In this model, the therapeutic value can be assessed using behavioral, biochemical, and histochemical measurements. The delay of nigral neuronal death with respect to the time of 6-OHDA administration may provide a therapeutic window for testing neuroprotective strategies.
Growth inhibition of human malignant glioma cells induced by the PI3-K—specific inhibitor
Authors: Shingu Takashi , Yamada Kazuo , Hara Nobumasa , Moritake Kouzo , Osago Harumi , Terashima Masaharu , Uemura Takeshi , Yamasaki Toshiki , Tsuchiya Mikako 
Published: May 2009

Object. The phosphatase and tensin homolog deleted from chromosome 10 (PTEN) functions as a tumor suppressor by negatively regulating the growth/survival signals of the phosphatidylinositol 3-kinase (PI3-K)/Akt pathway. The PI3-K/Akt pathway in PTEN-deficient tumors may be one of the key targets for anticancer therapy. The authors examined the effects of the PI3-K inhibitor 2-(4-morpholinyl)-8-phenylchromone (LY294002) on human malignant glioma cells, and compared these effects on PTEN-deficient cells with those on PTEN—wild-type (PTEN-wt) cells.
Methods. Using human malignant glioma cell lines, including the PTEN-deficient cells A172 and U87MG and the PTEN-wt cells LN18 and LN229, the effects of LY294002 on cell growth, apoptosis, and chemotherapeutic agent—induced cytotoxicity were evaluated. The LY294002 inhibited the growth of U87MG cells associated with reduced phosphatidylinositol 3,4,5,-trisphosphate and phosphorylated Akt, and also induced growth inhibition in three other cell lines. Although LY294002 caused apoptosis in all four cell lines, apoptosis seemed to contribute to only a small portion of growth inhibition induced by LY294002. There was no link between the status of PTEN and the median inhibitory concentration values for LY294002 or between the gene status and the extent of LY294002-induced apoptosis. The LY294002 significantly augmented the cytotoxicity induced by etoposide in PTEN-deficient cells, but not in PTEN-wt cells. Enhancement of 1,3-bis(2-chloroethyl)-1-nitrosourea— and cisplatin-induced cytotoxicity by LY294002 was not linked to the status of PTEN. No marked difference in the amounts of phosphorylated Akt was found between PTEN-deficient and PTEN-wt cells.
Conclusions. The findings show that PI3-K is a possible target for therapy in patients with gliomas, and PI3-K inhibitors in combination with chemotherapeutic agents could be potent therapeutic modalities for patients with malignant gliomas.
Comparative genomic hybridization analysis of craniopharyngiomas
Authors: Rienstein Shlomit , Adams Eric F. , Pilzer David , Goldring Ayala Aviram , Goldman Boleslaw , Friedman Eitan 
Published: May 2009

Object. Craniopharyngioma is the most common childhood brain tumor and is thought to arise from embryonic remnants of the Rathke pouch. Some craniopharyngiomas are monoclonal in origin and hence presumably harbor somatic genetic alterations, although the precise molecular mechanisms involved in craniopharyngioma development are unknown. The goal of this study was to identify genetic alterations in craniopharyngiomas.
Methods. To gain insight into the molecular mechanisms involved in development of these tumors, the authors analyzed nine adamantinomatous craniopharyngiomas by using comparative genomic hybridization. Six tumors (67%) displayed at least one genomic alteration, and three had six or more alterations. Only two tumors displayed a decrease in DNA copy number, and in all others an increase in DNA copy number was noted.
Conclusions. The authors conclude that a subset of craniopharyngiomas consists of monoclonal tumors arising from activation of oncogenes located at specific chromosomal loci.
Motor cortex stimulation in a patient with intractable complex regional pain syndrome Type II with hemibody involvement
Authors: Son Byung Chul , Kim Moon Chan , Moon Dong Eon , Kang Joon Ki 
Published: May 2009

✓ The authors describe the effectiveness of motor cortex stimulation (MCS) in a patient with complex regional pain syndrome (CRPS) Type II, formerly known as causalgia, with hemibody allodynia. During MCS, a subjective sensation of warm paresthesia developed in the painful hand and forearm and spread toward the trunk. Pain and allodynia in the areas associated with this sensation were alleviated significantly. The analgesic effect of stimulation proved to be long lasting and was still present at the 12-month follow up.
The authors speculate that MCS might exert its effect through the modulation of thalamic activity in this particular case of CRPS with hemisensory deficit. A central mechanism associated with functional disturbance in noxious-event processing in the thalamus might have an important role in the pathogenesis of the condition.
Histopathological findings in a human carotid artery after stent implantation
Authors: Toma Naoki , Matsushima Satoshi , Murao Kenichi , Kawaguchi Kenji , Imanaka-Yoshida Kyoko , Yoshida Toshimichi , Taki Waro 
Published: May 2009

✓ Despite the high technical success rates and the acceptable morbidity and mortality rates that are associated with carotid artery (CA) stent implantation, morphological changes in the vessel wall after this procedure are still unknown. The authors describe histopathological findings of the CA after stent implantation in a human autopsy specimen.
A 75-year-old man with asymptomatic CA stenosis underwent successful CA stent implantation, but died 8 months afterward of complications surrounding treatment of a thoracic aortic artery aneurysm. The stented CA was isolated from the autopsy specimen and was analyzed macroscopically and with the aid of scanning electron microscopy and histopathological methods.
Although there was focal persistence of a chronic inflammatory reaction around the stent struts, a stabilized neointima overlying the stent, which was principally composed of cells that stained positively for α—smooth muscle actin and collagen deposition with complete reendothelialization of the luminal surface, was confirmed in the internal CA. In contrast, residual mural thrombus around the stent struts in the common CA led to a concern about the potential risk for distal embolism in the future. The present case provides supportive evidence of stabilized neointima overlying the stent and valuable information regarding morphological characteristics useful for selecting a stent of an appropriate size.
Quantitative pupillometry, a new technology: normative data and preliminary observations in patients with acute head injury
Authors: Taylor William R. , Chen Jeff W. , Meltzer Hal , Gennarelli Thomas A. , Kelbch Cynthia , Knowlton Sharen , Richardson Jenny , Lutch Matthew J. , Farin Azadeh , Hults Kathryn N. , Marshall Lawrence F. 
Published: May 2009

✓ The authors prospectively used a new hand-held point-and-shoot pupillometer to assess pupillary function quantitatively. Repetitive measurements were initially made in more than 300 healthy volunteers ranging in age from 1 to 87 years, providing a total of 2432 paired (alternative right eye, left eye) measurements under varying light conditions. The authors studied 17 patients undergoing a variety of nonintracranial, nonophthalmological, endoscopic, or surgical procedures and 20 seniors in a cardiology clinic to learn more about the effects of a variety of drugs. Additionally, the authors carried out detailed studies in 26 adults with acute severe head injury in whom intracranial pressure (ICP) was continuously monitored. Finally, five patients suffering from subarachnoid hemorrhage were also studied.
Quantitative pupillary measurements could be reliably replicated in the study participants. In healthy volunteers the resting pupillary aperture averaged 4.1 mm and the minimal aperture after stimulation was 2.7 mm, resulting in a 34% change in pupil size. Constriction velocity averaged 1.48 ± 0.33 mm/second. Pupillary symmetry was striking in both healthy volunteers and patients without intracranial or uncorrected visual acuity disorders. In the 2432 paired measurements in healthy volunteers, constriction velocity was noted to fall below 0.85 mm/second on only 33 occasions and below 0.6 mm/second on eight occasions (< one in 310 observations).
In outpatients, the reduction in constriction velocity was observed when either oral or intravenous narcotic agents and diazepam analogs were administered. These effects were transient and always symmetrical.
Among the 26 patients with head injuries, eight were found to have elevations of ICP above 20 mm Hg and pupillary dynamics in each of these patients remained normal. In 13 patients with a midline shift greater than 3 mm, elevations of ICP above 20 mm Hg, when present for 15 minutes, were frequently associated with a reduction in constriction velocity on the side of the mass effect to below 0.6 mm/second (51% of 156 paired observations). In five patients with diffuse brain swelling but no midline shift, a reduction in constriction velocities did not generally occur until the ICP exceeded 30 mm Hg. Changes in the percentage of reduction from the resting state following stimulation were always greater than 10%, even in patients receiving large doses of morphine and propofol in whom the ICP was lower than 20 mm Hg. Asymmetry of pupillary size greater than 0.5 mm was observed infrequently (< 1%) in healthy volunteers and was rarely seen in head-injured patients unless the ICP exceeded 20 mm Hg. Pupillometry is a reliable technology capable of providing repetitive data on quantitative pupillary function in states of health and disease.
Noninvasive intracranial compliance monitoring
Authors: Lang Erhard W. , Paulat Klaus , Witte Christoph , Zolondz Jürgen , Mehdorn H. Maximilian 
Published: May 2009

✓ Although invasive measurement of intracranial pressure (ICP) involving high-resolution waveform analysis allows assessment of intracranial compliance (ICC), it is only feasible in a few selected neurosurgical conditions. Intracranial compliance can be assessed using the high-frequency centroid (HFC), which is the power-weighted mean frequency within the 4 to 15—Hz band of the ICP waveform. The authors have systematically tested the utility, performance, and reliability of a noninvasive monitor of ICC. The underlying principle of this device is that the ICP transmission and its infrasonic waves are transmitted through the inner ear toward the tympanic membrane. If the outer ear is sealed in an airtight fashion, motions of the tympanic membrane cause air pressure fluctuations that can be recorded using a special sensor.
The authors compared the HFC calculated from an intraparenchymal ICP sensor with that obtained simultaneously from an ipsilaterally placed noninvasive device during half of a respiratory cycle (peak to baseline) as well as for three random samples of three heart cycles. They analyzed 32 sessions in 13 patients in whom mechanical ventilation had been established. In four (11%) of 36 sessions they could not demonstrate an adequate signal.
For the peak-to-baseline cycle, the mean invasively recorded HFC was 8.05 ± 0.55 Hz (range 6.7–9 Hz) whereas the mean noninvasively recorded HFC was 8.04 ± 0.49 Hz (range 7–9.3 Hz). The ICP was 8.5 ± 5 mm Hg (range 2–24 mm Hg). For the three heart cycles randomly sampled, the values were 7.73 ± 0.51 Hz (range 6.7–8.6 Hz) and 7.76 ± 0.56 mm Hg (range 6.5–8.8 mm Hg), respectively.
This device allows noninvasive assessment of ICC based on the HFC waveform analysis that is equivalent to that obtained by invasive intraparenchymal recording. The monitoring device may become a valuable tool for monitoring parameters in patients in whom placement of an intracranial sensor is not feasible but assessment of ICC as an alternative to ICP measurement is desired.
Functional magnetic resonance imaging and control over the biceps muscle after intercostal—musculocutaneous nerve transfer
Authors: Malessy Martijn J. A. , Bakker Dick , Dekker Ad J. , van Dijk J. Gert , Thomeer Ralph T. W. M. 
Published: May 2009

Object. Recent progress in the understanding of cerebral plastic changes that occur after an intercostal nerve (ICN)—musculocutaneous nerve (MCN) transfer motivated a study with functional magnetic resonance (fMR) imaging to map reorganization in the primary motor cortex.
Methods. Eleven patients with traumatic root avulsions of the brachial plexus were studied. Nine patients underwent ICN—MCN transfer to restore biceps function and two patients were studied prior to surgery. The biceps muscle recovered well in seven patients who had undergone surgery and remained paralytic in the other two patients. Maps of neural activity within the motor cortex were generated for both arms in each patient by using fMR imaging, and the active pixels were counted. The motor task consisted of biceps muscle contraction. Patients with a paralytic biceps were asked to contract this muscle virtually. The location and intensity of motor activation of the seven surgically treated arms that required good biceps muscle function were compared with those of the four arms with a paralytic biceps and with activity obtained in the contralateral hemisphere regulating the control arms.
Activity could be induced in the seven surgically treated patients whose biceps muscles had regained function and was localized within the primary motor area. In contrast, activity could not be induced in the four patients whose biceps muscles were paralytic. Neither the number of active pixels nor the mean value of their activations differed between the seven arms with good biceps function and control arms. The weighted center of gravity of the distribution of activity also did not appear to differ.
Conclusions. Reactivation of the neural input activity for volitional biceps control after ICN—MCN transfer, as reflected on fMR images, is induced by successful biceps muscle reinnervation. In addition, the restored input activity does not differ from the normal activity regulating biceps contraction and, therefore, has MCN acceptor qualities. After ICN—MCN transfer, cerebral activity cannot reach the biceps muscle following the normal nervous system pathway. The presence of a common input response between corticospinal neurons of the ICN donor and the MCN acceptor seems crucial to obtain a functional result after transfer. It may even be the case that a common input response between donor and acceptor needs to be present in all types of nerve transfer to become functionally effective.
Symptomatic vasospasm and outcomes following aneurysmal subarachnoid hemorrhage: a comparison between surgical repair and endovascular coil occlusion
Authors: Rabinstein Alejandro A. , Pichelmann Mark A. , Friedman Jonathan A. , Piepgras David G. , Nichols Douglas A. , McIver Jon I. , Toussaint L. Gerard , McClelland Robyn L. , Fulgham Jimmy R. , Meyer Fredric B. , Atkinson John L. D. , Wijdicks Eelco F. M. 
Published: May 2009

Object. The authors studied patients with aneurysmal subarachnoid hemorrhage (SAH) to determine whether the incidence of symptomatic vasospasm or overall clinical outcomes differed between patients treated with craniotomy and clip application and those treated by endovascular coil occlusion.
Methods. The authors reviewed 415 consecutive patients with aneurysmal SAH who had been treated with either craniotomy and clip application or endovascular coil occlusion at a single institution between 1990 and 2000. Three hundred thirty-nine patients underwent surgical clip application procedures, whereas 76 patients underwent endovascular coil occlusion.
Symptomatic vasospasm occurred in 39% of patients treated with clip application, 30% of patients treated with endovascular coil occlusion, and 37% of patients overall. Compared with patients treated with clip application, patients treated with endovascular coil occlusion were more likely to suffer acute hydrocephalus (50 compared with 34%, p = 0.008) and were more likely to harbor aneurysms in the posterior circulation (53 compared with 20%, p < 0.001). Logistic regression models controlling for patient age, admission World Federation of Neurosurgical Societies (WFNS) grade, acute hydrocephalus, aneurysm location, and day of treatment revealed that, among patients with an admission WFNS grade of I to III, endovascular coil occlusion carried a lower risk of symptomatic vasospasm (odds ratio [OR] 0.34, 95% confidence interval [CI] 0.14—0.8) and death or permanent neurological deficit due to vasospasm (OR 0.28, 95% CI 0.08–1) compared with craniotomy and clip application. Similar models revealed no difference in the likelihood of a Glasgow Outcome Scale score of 3 or less at the longest follow-up review (median 6 months) between treatment groups (OR 0.58, 95% CI 0.28–1.21).
Conclusions. Patients with better clinical grades (WFNS Grades I–III) at hospital admission were less likely to suffer symptomatic vasospasm when treated by endovascular coil occlusion, compared with craniotomy and clip application. Nevertheless, there was no significant difference in overall outcome at the longest follow-up examination between the two treatment groups.
Diurnal and seasonal variations in the onset of primary intracerebral hemorrhage in individuals living in Izumo City, Japan
Authors: Inagawa Tetsuji 
Published: May 2009

Object. Little is known about the temporal patterns of primary intracerebral hemorrhage (ICH) among the general population. The aim of this study was to examine diurnal and seasonal variations in the onset of ICH in a community-based series.
Methods. The study population consisted of 350 patients who presented with primary ICH for the first time and were treated between 1991 and 1998 in Izumo City, Japan. Among the entire patient population, the onset of hemorrhage was rarely observed during the night and a peak was observed in the late afternoon. In men 69 years of age or younger, the onset of ICH exhibited a bimodal distribution, with an initial high peak between 8:00 and 10:00 a.m. and a second, lower peak between 6:00 and 8:00 p.m. In contrast, in men 70 years of age or older and in women regardless of age, only a single evening peak, between approximately 6:00 and 10:00 p.m., was found, and no morning peak was observed. For the entire patient population (for both sexes), and for men alone, seasonal variations—a peak in winter and a trough in summer—were significant for all age groups combined. This factor was significant for patients 69 years of age or younger, during the daytime hours (8:00 a.m.–8:00 p.m.), and for patients with untreated hypertension; however, it was not significant for patients 70 years of age or older, during nighttime hours (10:00 p.m.–8:00 a.m.), or for treated hypertensive and normotensive patients. In women, no significant seasonal patterns were found, regardless of patient age, time of day at onset of ICH, or the presence of risk factors. Seasonal variations were statistically significant for patients with hematomas larger than 5 ml, but not for those with hematomas 5 ml or smaller.
Conclusions. Temporal distributions in the onset of ICH seem to be influenced by patient sex and age. The seasonal patterns of ICH occurrence may result mainly from changes that occur during the daytime, and may also be modified by the presence of untreated hypertension and by the volume of the hematoma.