bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reversible dementia in patients with chronic subdural hematomas
Authors: Ishikawa Eiichi , Yanaka Kiyoyuki , Sugimoto Koichi , Ayuzawa Satoshi , Nose Tadao 
Published: May 2009

Object. Neuropsychiatric changes following surgery for chronic subdural hematomas (CSDHs) were analyzed in 26 patients (21 men and five women) by using the Mini-Mental State Examination (MMSE) and the Hasegawa Dementia Scale—Revised (HDS-R) to determine factors that potentially contribute to neuropsychiatric recovery.
Methods. Burr hole irrigation was performed in every patient to treat the CSDH. The patients' profiles, including age and sex, neuroimaging findings (such as hematoma volume and thickness, as well as midline shift), and preoperative and postoperative scores on the MMSE, HDS-R, and activities of daily living (ADL) scale were recorded. According to preoperative MMSE scores, eight patients (30.8%) were classified as mentally healthy and 18 (69.2%) as suffering from dementia before surgery. Nine of the 18 patients with dementia recovered to a normal psychological state following surgery. Surgery improved not only the patients' independence in ADL (p = 0.0026), but also their neuropsychiatric functions such as orientation and calculation, as estimated by scores on the MMSE (p = 0.0002) and the HDS-R (p = 0.0008). Factors affecting neuropsychiatric status on admission were midline shift (p = 0.0398) and ADL score (p = 0.0124); factors that could be used to predict neuropsychiatric recovery after surgery were patient age (p = 0.0027) and ADL score (p = 0.0193). The results of a logistic regression analysis demonstrated that significant predictors of neuropsychiatric recovery after surgery include the following: patient age (p = 0.0049, odds ratio [OR] = 0.842) and preoperative ADL (p = 0.0056, OR = 0.471), MMSE (p < 0.0001, OR = 1.895), and HDS-R (p = 0.0073, OR = 1.303) scores. Results of subgroup analyses demonstrated that patients younger than 74 years of age and those who had preoperative scores lower than 5 on the converted ADL scale, higher than 10 on the MMSE, or higher than 9 on the HDS-R on admission were found to have a significantly better recovery of neuropsychiatric functions after surgery.
Conclusions. Dementia is reversible in many patients with CSDH, and surgery can improve not only independence in ADL, but also neuropsychiatric functions. Patients who are younger and/or those who have lower preoperative ADL scores and/or higher preoperative MMSE or HDS-R scores will achieve a good recovery with regard to neuropsychiatric functions after surgery. Estimations of neuropsychiatric function based on MMSE and HDS-R scores were found to be useful in predicting functional outcomes in patients with CSDH.
Waterjet dissection in neurosurgical procedures: clinical results in 35 patients
Authors: Piek Juergen , Oertel Joachim , Robert Gaab Michael 
Published: May 2009

Object. Waterjet dissection represents a new minimally traumatic surgical method for dissection that can be used in various parenchymal organs, in which it allows highly precise parenchymal dissection while preserving blood vessels, resulting in reduced intraoperative blood loss. This study was performed to investigate the clinical application of this new technique in neurosurgical procedures, such as brain tumor resection and epilepsy surgery.
Methods. Thirty-four patients with gliomas (Grades II–IV), cerebral metastases, temporal lobe epilepsy, or cerebellar hemangioblastomas, and one patient with internal carotid artery (ICA) stenosis were treated surgically with the aid of the waterjet. Resection was performed using waterjet dissection in combination with conventional neurosurgical procedures. Intraoperatively, the waterjet was easy to handle, and no complications due to the device were observed. Dissection of tissue was possible for all pathological conditions, and pressures between 3 and 45 bars were used. In gliomas, metastases, epilepsy surgery, and hemangioblastoma, the tissue was dissected at pressures between 3 and 17 bars, which preserved blood vessels. Dissection of meningiomas and the ICA stenosis required higher pressures (between 20 and 45 bars); with these pressures, blood vessels were also dissected.
Conclusions. These results indicate that the waterjet dissection procedure can be used intraoperatively without complications. This device appears to be particularly suitable for the dissection of highly vascularized gliomas or normal brain tissue, in which tissue dissection with sparing of blood vessels can be achieved. To prove that this is a useful addition to the neurosurgical armamentarium, reduction of blood loss or postoperative brain edema compared with conventional methods should be demonstrated in future studies.
Magnetic resonance angiographic evidence of sex-linked variations in the circle of Willis and the occurrence of cerebral aneurysms
Authors: Horikoshi Toru , Akiyama Iwao , Yamagata Zentaro , Sugita Masao , Nukui Hideaki 
Published: May 2009

Object. In this study the authors investigated the relationship between variations in the circle of Willis observed on magnetic resonance (MR) angiograms and locations of cerebral aneurysms, and evaluated the risk of aneurysm formation.
Methods. One hundred thirty-one patients with cerebral aneurysms were retrospectively selected from a series of 4518 patients who underwent MR angiography at one neurosurgical institute. Variations in the anatomy of the circle of Willis were simply classified into Type A, in which there was no visualization of a unilateral A1 segment, and Type P, in which there was a fetal type of posterior cerebral artery that was continuously delineated from the internal carotid artery (ICA) through the posterior communicating artery. All other variations in the circle of Willis were defined as Type O (ordinary type of variations). An additional 440 patients who did not harbor cerebral aneurysms were randomly selected for a comparison.
Anterior communicating artery aneurysms were significantly related to the Type A anatomy and ICA aneurysms to Type P anatomy. Male patients who did not harbor aneurysms tended to have Type A anatomy, whereas women had a significantly greater incidence of Type P.
Conclusions. This sex-linked difference in anatomical variations may be correlated to the well-known sex-linked difference in aneurysm distribution.
Detection and significance of focal, interictal, slow-wave activity visualized by magnetoencephalography for localization of a primary epileptogenic region
Authors: Ishibashi Hideaki , Simos Panagiotis G. , Castillo Eduardo M. , Maggio William W. , Wheless James W. , Kim Howard L. , Venkataraman Vijay , Sanders Daniel K. , Breier Joshua I. , Zhang Wenbo , Davis Robert N. , Papanicolaou Andrew C. 
Published: May 2009

Object. Magnetoencephalography (MEG) is a novel noninvasive diagnostic tool used to determine preoperatively the location of the epileptogenic zone in patients with epilepsy. The presence of focal slowing of activity recorded by electroencephalography (EEG) is an additional indicator of an underlying pathological condition in cases of intractable mesial temporal lobe epilepsy (MTLE). In the present study the authors examined the significance of focal, slow-wave and interictal spike activity detected using MEG in 29 patients who suffered from MTLE that was not associated with structural brain lesions.
Methods. All patients underwent resective surgery after MEG and EEG monitoring. Equivalent single-dipole modeling was applied to focal low-frequency magnetic activity (LFMA) and interictal paroxysmal activity. Lateralized LFMA was defined as trains of rhythmic activity over the temporal area, with frequencies lower than 7 Hz, which were easily distinguished from background activity.
Lateralized LFMA was found in 17 patients (58.6%); it always occurred on the side ipsilateral to the side of resection and displayed a maximum amplitude over the temporal area. Dipolar sources of magnetic flux computed during slow-wave trains were found in the majority of cases in the posterior superior temporal region and, occasionally, in mesial temporal structures that were subsequently resected. With respect to lateralization there was never disagreement between LFMA and MEG interictal spike sources. Thus, in patients with MTLE that is not associated with a mass lesion LFMA is topographically related to the epileptogenic area and, therefore, has value for reliable determination of the side and, possibly, the location of this area.
Conclusions. Although focal slowing of EEG background activity is generally considered to be a nonspecific sign of functional disturbance, interictal LFMA in patients with MTLE should be conceptualized as a distinct electrographic phenomenon that is directly related to the epileptogenic abnormality. Analyzing the interictal MEG distribution of LFMA and sharp activity improves the diagnostic utility of MEG in patients with suspected TLE who are undergoing surgical evaluation.
Reversible ischemia around intracerebral hemorrhage: a single-photon emission computerized tomography study
Authors: Siddique M. Shahid , Fernandes Helen M. , Wooldridge Thomas D. , Fenwick John D. , Slomka Piotr , Mendelow A. David 
Published: May 2009

Object. A zone of perilesional ischemia has been demonstrated around intracerebral hemorrhage (ICH) in numerous experimental models and in human studies. There is potential for perfusion recovery in the zone of perilesional oligemia around ICH. The authors sought to demonstrate, quantify, and study the chronological evolution of perilesional ischemic change in ICH in humans by measuring cerebral blood flow.
Methods. Eleven patients with spontaneous supratentorial ICH underwent two technetium-99m hexamethylpropyleneamine oxime single-photon emission computerized tomography (SPECT) scanning, one in the acute stage (within days of ictus) and the other in the late stage (6–9 months postictus). All patients in this study were treated nonsurgically. Methods of SPECT data analysis based on count differences in regions of interest can be difficult to apply to images with large space-occupying lesions such as ICH, because of the distortion of intracranial anatomy, midline shift, and alterations in the three-dimensional (3D) characteristics of the lesion over time (that is, absorption of the hematoma on the later studies). The authors used the following method: the late and early images were registered and aligned to a common 3D orientation and were normalized to maximal counts. The late images were then compared voxel by voxel with the early ones. The region-growing algorithm was used to discern the difference between the two images, outlining voxels in the perihematoma region, with a signal improvement of at least 15% on the late image.
Discrete brain regions around the hematoma with at least a 15% improvement in radiotracer uptake (and hence perfusion) in the late images were observed in all cases. The mean volume of brain with a greater than 15% improvement in perfusion between the two studies was 34.8 cm3 (range 7.2–71.3 cm3). These volumes represent regions of the brain that were poorly perfused in the initial studies. This may represent a zone of reversible perilesional oligemia (penumbra) in ICH in humans.
Conclusions. This is the first study in which it is documented that some of the perilesional hypoperfused tissue around human ICH regains its perfusion in the long term, leading the authors to suggest that there may be a penumbra in human ICH. Medical or surgical therapeutic interventions could increase the volume of perilesional brain that recovers after the initial insult. The results of this study therefore support the concept that intervention in ICH has the potential to reduce the ultimate neurological deficit and improve outcome.
Compartments in arteriovenous malformation nidi demonstrated with rotational three-dimensional digital subtraction angiography by using selective microcatheterization
Authors: Kakizawa Yukinari , Nagashima Hisashi , Oya Fusakazu , Ito Kiyoshi , Tanaka Yuichiro , Hongo Kazuhiro , Kobayashi Shigeaki 
Published: May 2009

✓ Although in several histological studies of arteriovenous malformation (AVM) nidi the presence of compartments has been documented, no clinical study has been published. The present study was conducted to determine the presence of nidus compartments in clinical cases by using a new radiographic method.
Two patients with unruptured and one with a ruptured AVM (all Spetzler—Martin Grade III) were studied. A microcatheter was superselectively introduced into each of two or three feeding arteries of the AVMs under three-dimensional (3D) angiographic guidance to obtain 3D images of the nidus by using rotational digital subtraction angiography. On 3D images the different feeding arteries were found to be independent from one another, which allowed the authors to confirm the presence of compartments. On the other hand, separate feeding arteries often had a common draining vessel. Compartments in AVM nidi were demonstrated by a novel rotational 3D angiographic procedure by using superselective microcatheterization, which should be useful for designing treatment strategies for large and complex AVMs.
Hearing restoration after resection of an intracanalicular vestibular schwannoma: a role for emergency surgery?
Authors: Meiteles Lawrence Z. , Liu James K. , Couldwell William T. 
Published: May 2009

✓ Patients with vestibular schwannomas (VSs) most commonly present with sensorineural hearing loss, which is often insidious or gradual. Up to 26% of patients may present with sudden hearing loss, however, which poses an important surgical challenge. Sudden hearing loss has been attributed to spasm or occlusion of the labyrinthine artery resulting from tumor compression, and it is usually treated with corticosteroids. Hearing preservation surgery is not usually attempted in patients who have poor or nonserviceable hearing preoperatively.
The authors describe a 68-year-old man with complete deafness of the left ear since childhood, who developed sudden, profound sensorineural hearing loss in the right ear. Magnetic resonance imaging revealed a small right-sided intracanalicular tumor. Treatment with high-dose corticosteroids produced only minimal improvement in hearing. Subsequent emergency decompression and resection of a VS resulted in rapid improvement and restoration of hearing, with facial nerve preservation.
Although most neurotologic lesions in patients with hearing in only one ear are managed nonsurgically, resection of small tumors in the setting of sudden hearing loss should be considered in selected cases. This finding indicates that a therapeutic window may exist during which sudden hearing loss caused by intracanalicular tumors is reversible.
Analysis of homozygous deletion of the p16 gene and correlation with survival in patients with glioblastoma multiforme
Authors: Kamiryo Takanori , Tada Kenji , Shiraishi Shoji , Shinojima Naoki , Nakamura Hideo , Kochi Masato , Kuratsu Jun-ichi , Saya Hideyuki , Ushio Yukitaka 
Published: May 2009

Object. One of the most frequent genetic abnormalities found in patients with glioblastoma multiforme (GBM) is homozygous deletion of the p16 tumor suppressor gene. The authors investigated whether this deletion is associated with prognosis in patients with GBM.
Methods. In 46 adult patients with supratentorial GBM, homozygous deletion of the p16 gene in tumor DNA was examined using the multiplex polymerase chain reaction assay. The deletion was confirmed in 14 (30.4%) of 46 patients, eight (30.8%) of 26 men and six (30.0%) of 20 women. Cox proportional hazard regression analysis, adjusted for age at surgery, the Karnofsky Performance Scale score, extent of resection, and the MIB-1 labeling index, revealed that homozygous deletion of the p16 gene was significantly associated with overall survival and progression-free survival in men, but not in women.
Conclusions. The results of this study suggest that p16 homozygous deletion is a significant unfavorable prognostic factor in male patients with GBM.
Stereotactic radiosurgery for the treatment of dural arteriovenous fistulas involving the transverse—sigmoid sinus
Authors: Pan David Hung-chi , Chung Wen-yuh , Guo Wan-yuo , Wu Hsiu-mei , Liu Kang-du , Shiau Cheng-ying , Wang Ling-wei 
Published: May 2009

Object. The aim of this study was to assess the efficacy and safety of radiosurgery for the treatment of dural arteriovenous fistulas (DAVFs) located in the region of the transverse—sigmoid sinus.
Methods. A series of 20 patients with DAVFs located in the transverse—sigmoid sinus, who were treated with gamma knife surgery between June 1995 and June 2000, was evaluated. According to the Cognard classification, the DAVF was Type I in four patients, Type IIa in seven, Type IIb in two, and combined Type IIa+b in seven. Nine patients had previously been treated with surgery and/or embolization, whereas 11 patients underwent radiosurgery alone. Radiosurgery was performed using multiple-isocenter irradiation of the delineated DAVF nidus. The target volume ranged from 1.7 to 40.7 cm3. The margin dose delivered to the nidus ranged from 16.5 to 19 Gy at a 50 to 70% isodose level.
Nineteen patients were available for follow-up review, the duration of which ranged from 6 to 58 months (median 19 months). Of the 19 patients, 14 (74%) were cured of their symptoms. At follow up, magnetic resonance imaging and/or angiography demonstrated complete obliteration of the DAVF in 11 patients (58%), subtotal obliteration (95% reduction of the nidus) in three (16%), and partial obliteration in another five (26%). There was no neurological complication related to the treatment. One patient experienced a recurrence of the DAVF 18 months after angiographic confirmation of total obliteration, and underwent a second course of radiosurgery.
Conclusions. Stereotactic radiosurgery provides a safe and effective option for the treatment of DAVFs involving the transverse and sigmoid sinuses. For some aggressive DAVFs with extensive retrograde cortical venous drainage, however, a combination of endovascular embolization and surgery may be necessary.
Multicenter study of the feasibility and safety of using the Memotherm carotid arterial stent for extracranial carotid artery stenosis
Authors: Qureshi Adnan I. , Suri M. Fareed K. , New Gishel , Wadsworth Daniel C. , Dulin Joan , Hopkins L. Nelson 
Published: May 2009

Object. Carotid artery (CA) angioplasty with stent placement has been proposed as an alternative technique for revascularization in cases of CA stenosis. In this report the authors review the results of a multicenter Phase I study in which they evaluated the safety and feasibility of using a new self-expanding nitinol stent, the Bard Memotherm, to treat CA stenosis.
Methods. Enrollment was limited to patients in whom there was either 50% or greater symptomatic or 70% or greater asymptomatic stenosis of the internal CA. The primary endpoint was a technically successful implantation procedure (delivery of the stent to the target site and retrieval of the delivery device), resulting in less than 30% residual stenosis demonstrated on immediate postprocedure (control) angiograms, and no incidence of mortality, ipsilateral stroke, Q-wave myocardial infarction, or other major cardiovascular events immediately after or within 30 days following the procedure.
Stent placement was attempted for 73 lesions in 71 patients (mean age 71.3 ± 8.5 years), 43 (61%) of whom were men. The mean degree of stenosis was 82.6 ± 9%. The stenosis was symptomatic in 27 (37%) and asymptomatic in 46 (63%) of 73 lesions. In four procedures the stent could not be delivered or released. The mean residual stenosis observed on angiograms was 3.8 ± 6.9% in the 69 lesions treated with the Bard Memotherm stent; residual stenosis was greater than 30% in one of the 69 procedures. The primary endpoint was achieved in 65 (89%) of the 73 procedures. One patient experienced a major ischemic stroke and another patient died of intracerebral hemorrhage. The overall 1-month stroke rate was 2.7% for 73 attempted procedures. One patient died of pneumonia and acute respiratory distress syndrome, which occurred 3 weeks after the stent procedure and was unrelated to the procedure.
Conclusions. The Memotherm stent can be used to treat patients with CA stenosis and is associated with a low periprocedure complication rate. Long-term follow-up studies are underway to determine the impact of stent placement on the risk of ipsilateral ischemic events.
Optimal location of thalamotomy lesions for tremor associated with Parkinson disease: a probabilistic analysis based on postoperative magnetic resonance imaging and an integrated digital atlas
Authors: Atkinson Jeffrey D. , Collins D. Louis , Bertrand Gilles , Peters Terry M. , Pike G. Bruce , Sadikot Abbas F. 
Published: May 2009

Object. Renewed interest in stereotactic neurosurgery for movement disorders has led to numerous reports of clinical outcomes associated with different treatment strategies. Nevertheless, there is a paucity of autopsy and imaging data that can be used to describe the optimal size and location of lesions or the location of implantable stimulators. In this study the authors correlated the clinical efficacy of stereotactic thalamotomy for tremor with precise anatomical localization by using postoperative magnetic resonance (MR) imaging and an integrated deformable digital atlas of subcortical structures.
Methods. Thirty-one lesions were created by stereotactic thalamotomy in 25 patients with tremor-dominant Parkinson disease. Lesion volume and configuration were evaluated by reviewing early postoperative MR images and were correlated with excellent, good, or fair tremor outcome categories. To allow valid comparisons of configurations of lesions with respect to cytoarchitectonic thalamic boundaries, the MR image obtained in each patient was nonlinearly deformed into a standardized MR imaging space, which included an integrated atlas of the basal ganglia and thalamus. The volume and precise location of lesions associated with different clinical outcomes were compared using nonparametric statistical methods. Probabilistic maps of lesions in each tremor outcome category were generated and compared.
Statistically significant differences in lesion location between excellent and good, and excellent and fair outcome categories were demonstrated. On average, lesions associated with excellent outcomes involved thalamic areas located more posteriorly than sites affected by lesions in the other two outcome groups. Subtraction analysis revealed that lesions correlated with excellent outcomes necessarily involved the interface of the nucleus ventralis intermedius (Vim; also known as the ventral lateral posterior nucleus [VLp]) and the nucleus ventrocaudalis (Vc; also known as the ventral posterior [VP] nucleus). Differences in lesion volume among outcome groups did not achieve statistical significance.
Conclusions. Anatomical evaluation of lesions within a standardized MR image—atlas integrated reference space is a useful method for determining optimal lesion localization. The results of an analysis of probabilistic maps indicates that optimal relief of tremor is associated with lesions involving the Vim (VLp) and the anterior Vc (VP).