bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hearing preservation following fractionated stereotactic radiotherapy for vestibular schwannomas: prognostic implications of cochlear dose
Authors: Thomas Carys , Di Maio Salvatore , Ma Roy , Vollans Emily , Chu Christina , M.Math.  , Clark Brenda , Lee Richard , McKenzie Michael , Martin Montgomery , Toyota Brian 
Published: December 2007

Object
The goal in this study was to evaluate hearing preservation rates and to determine prognostic factors for this outcome following fractionated stereotactic radiotherapy (FSRT) of vestibular schwannoma.

Methods
Thirty-four consecutive patients with serviceable hearing who received FSRT between May 1998 and December 2003 were identified. Clinical and audiometry data were collected prospectively. The prescription dose was 45 Gy in 25 fractions prescribed to the 90% isodose line. The median follow-up duration was 36.5 months (range 12–85 months). The actuarial 2- and 4-year local control rates were 100 and 95.7%, respectively. Permanent trigeminal and facial nerve complications were 0 and 6%, respectively. The actuarial 2- and 3-year serviceable hearing preservation rates were both 63%. The median loss in speech reception threshold was 15 dB (range −10 to 65 dB). The radiotherapy dose to the cochlea was the only significant prognostic factor for hearing deterioration. Radiotherapy dose to the cochlear nucleus, patient age, sex, pre-FSRT hearing grade, tumor volume, and intracanalicular tumor volume failed to show any significance as prognostic factors.

Results
Five cases were replanned with four different radiotherapy techniques (namely arcs, dynamic arcs, static conformal fields, and intensity-modulated radiotherapy), with the cochlea defined as an organ at risk. In all cases, replanning resulted in statistically significant reduction in radiation to the cochlea (p = 0.001); however, no single replanning technique was found to be superior.

Conclusions
The radiation dose to the cochlea is strongly predictive for subsequent hearing deterioration. It is essential for the cochlea to be outlined as an organ at risk, and for radiation techniques to be optimized, to improve long-term hearing preservation.
Influence of different approaches to the cerebellopontine angle on the function of the intermediate nerve
Authors: Stripf Tobias , Braun Klarissa , Gouveris Haralampos , Stripf Esther A. , Mann Wolf J. , Amedee Ronald G. 
Published: December 2007

Object
Surgery in the cerebellopontine angle (CPA) is a standard procedure at many centers. Outcome is focused mainly on preservation of hearing and facial function postoperatively. The nonmotor part of the facial nerve, the intermediate nerve, is nearly neglected nowadays.

Methods
A retrospective study was designed, including a questionnaire that was sent to 178 patients who had undergone surgery between 2000 and 2004. Data were obtained in 156 cases. The questionnaire was divided into five parts assessing the presence of increased tearing, reduced tearing, salivation disturbances, increased nasal secretions, and abnormalities in taste. Finally, a self-assessment of patient symptoms was analyzed.

Results
Postoperatively, 70 patients (45%) experienced crocodile tears, whereas 62 (40%) had dry eyes. Disturbances in taste were noted in six patients (4%) preoperatively and in 52 patients (33%) after surgery. Increased nasal secretion was noted in 68 patients (44%) postoperatively. An analysis of the correlation between the surgical approach used and disturbances in the intermediate nerve revealed a strong tendency to a higher rate of symptoms following the middle fossa approach (p = 0.071, chi-square test).

Conclusions
Data in this study demonstrate the clinical importance of nonmotor defects associated with CPA tumor removal. More than 50% of the patients in this study reported postoperative crocodile tears, dry eyes, nasal secretions, and/or taste disturbances. These sequelae may affect both short- and long-term postoperative quality of life to the same extent as deafness or transient facial paresis. The risk of injury seems to be higher after the middle fossa approach.
Risk factors for subsequent hemorrhage in patients with cerebral arteriovenous malformations
Authors: Yamada Shigeki , Takagi Yasushi , Nozaki Kazuhiko , Kikuta Ken-ichiro , Hashimoto Nobuo 
Published: December 2007

Object
The aim of this study was to identify the natural history of untreated cerebral arteriovenous malformations (AVMs) and the risk factors for subsequent hemorrhage after an initial AVM diagnosis.

Methods
The authors studied 305 consecutive patients with AVMs at the Kyoto University Hospital between 1983 and 2005. These patients were followed up until the first subsequent hemorrhage, the start of any treatment, or the end of 2005. Possible risk factors that were investigated included age at initial diagnosis, sex, type of initial presentation, size and location of the AVM nidus, and the venous drainage pattern. Subsequent hemorrhage occurred in 26 patients from the hemorrhagic group during 380 patient–years, and in 16 patients from the nonhemorrhagic group during 512 patient–years.

Results
The annual bleeding rate in the hemorrhagic group was 6.84% after the initial hemorrhage; however, that rate decreased in the first 5 years (15.42% in the first year, 5.32% in the subsequent 4 years, and 1.72% in more than 5 years). In the nonhemorrhagic group (annual bleeding rate of 3.12%), the patients initially presenting with headaches (annual bleeding rate of 6.48%) or asymptomatic presentations (annual bleeding rate of 6.44%) had a higher risk for subsequent hemorrhage. Conversely, those patients presenting with seizures (annual bleeding rate of 2.20%) or neurological deficits (annual bleeding rate of 1.73%) had a lower risk. A significantly increased risk (p < 0.05) of rebleeding was found among children (hazard ratio [HR] = 2.69), females (HR = 2.93), or patients with deep-seated AVMs (HR = 3.07).

Conclusions
Children, females, and patients with deep-seated AVMs had a threefold increased risk of rebleeding after an initial cerebral AVM. This increased risk was highest in the first year after the initial hemorrhage, and thereafter gradually decreased.
Thalamic deep brain stimulation for writer's cramp
Authors: Fukaya Chikashi , Katayama Yoichi , Kano Toshikazu , Nagaoka Takafumi , Kobayashi Kazutaka , Oshima Hideki , Yamamoto Takamitsu 
Published: December 2007

Object
Writer's cramp is a type of idiopathic focal hand dystonia characterized by muscle cramps that accompany execution of the writing task specifically. In this report, the authors describe the clinical outcome after thalamic deep brain stimulation (DBS) therapy in patients with writer's cramp and present an illustrative case with which they compare the effects of pallidal and thalamic stimulation. In addition to these results for the clinical effectiveness, they also examine the best point and pattern for therapeutic stimulation of the motor thalamus, including the nucleus ventrooralis (VO) and the ventralis intermedius nucleus (VIM), for writer's cramp.

Methods
The authors applied thalamic DBS in five patients with writer's cramp. The inclusion criteria for the DBS trial in this disorder were a diagnosis of idiopathic writer's cramp and the absence of a positive response to medication. The exclusion criteria included significant cognitive dysfunction, active psychiatric symptoms, and evidence of other central nervous system diseases or other medical disorders. In one of the cases, DBS leads were implanted into both the globus pallidus internus and the VO/VIM, and test stimulation was performed for 1 week. The authors thus had an opportunity to compare the effects of pallidal and thalamic stimulation in this patient.

Results
Immediately after the initiation of thalamic stimulation, the neurological deficits associated with writer's cramp were improved in all five cases. Postoperatively all preoperative scale scores indicating the seriousness of the writer's cramp were significantly lower (p < 0.001). In the patient in whom two DBS leads were implanted, the clinical effect of thalamic stimulation was better than that of pallidal stimulation. During the thalamic stimulation, the maximum effect was obtained when stimulation was applied to both the VO and the VIM widely, compared with being applied only within the VO.

Conclusions
The authors successfully treated patients with writer's cramp by thalamic DBS. Insofar as they are aware, this is the first series in which writer's cramp has been treated with DBS. Thalamic stimulation appears to be a safe and valuable therapeutic option for writer's cramp.
Brain shift: an error factor during implantation of deep brain stimulation electrodes
Authors: Miyagi Yasushi , Shima Fumio , Sasaki Tomio 
Published: December 2007

Object
The goal of this study was to focus on the tendency of brain shift during stereotactic neurosurgery and the shift's impact on the unilateral and bilateral implantation of electrodes for deep brain stimulation (DBS).

Methods
Eight unilateral and 10 bilateral DBS electrodes at 10 nuclei ventrales intermedii and 18 subthalamic nuclei were implanted in patients at Kaizuka Hospital with the aid of magnetic resonance (MR) imaging–guided and microelectrode-guided methods. Brain shift was assessed as changes in the 3D coordinates of the anterior and posterior commissures (AC and PC) with MR images before and immediately after the implantation surgery. The positions of the implanted electrodes, based on the midcommissural point and AC–PC line, were measured both on x-ray films (virtual position) during surgery and the postoperative MR images (actual position) obtained on the 7th day postoperatively.

Results
Contralateral and posterior shift of the AC and PC were the characteristics of unilateral and bilateral procedures, respectively. The authors suggest the following. 1) The first unilateral procedure elicits a unilateral air invasion, resulting in a contralateral brain shift. 2) During the second procedure in the bilateral surgery, the contralateral shift is reset to the midline and, at the same time, the anteroposterior support by the contralateral hemisphere against gravity is lost due to a bilateral air invasion, resulting in a significant posterior (caudal) shift.

Conclusions
To note the tendency of the brain to shift is very important for accurate implantation of a DBS electrode or high frequency thermocoagulation, as well as for the prediction of therapeutic and adverse effects of stereotactic surgery.
Prospective randomized double-blind trial of bilateral thalamic deep brain stimulation in adults with Tourette syndrome
Authors: Maciunas Robert J. , Maddux Brian N. , Riley David E. , Whitney Christina M. , Schoenberg Mike R. , Ogrocki Paula J. , Albert Jeffrey M. , Gould Deborah J. 
Published: December 2007

Object
The severity of Tourette syndrome (TS) typically peaks just before adolescence and diminishes afterward. In some patients, however, TS progresses into adulthood, and proves to be medically refractory. The authors conducted a prospective double-blind crossover trial of bilateral thalamic deep brain stimulation (DBS) in five adults with TS.

Methods
Bilateral thalamic electrodes were implanted. An independent programmer established optimal stimulator settings in a single session. Subjective and objective results were assessed in a double-blind randomized manner for 4 weeks, with each week spent in one of four states of unilateral or bilateral stimulation. Results were similarly assessed 3 months after unblinded bilateral stimulator activation while repeated open programming sessions were permitted.

Results
In the randomized phase of the trial, a statistically significant (p < 0.03, Friedman exact test) reduction in the modified Rush Video-Based Rating Scale score (primary outcome measure) was identified in the bilateral on state. Improvement was noted in motor and sonic tic counts as well as on the Yale Global Tic Severity Scale and TS Symptom List scores (secondary outcome measures). Benefit was persistent after 3 months of open stimulator programming. Quality of life indices were also improved. Three of five patients had marked improvement according to all primary and secondary outcome measures.

Conclusions
Bilateral thalamic DBS appears to reduce tic frequency and severity in some patients with TS who have exhausted other available means of treatment.
Oligoclonal immune response in cerebral cavernous malformations
Authors: Shi Changbin , Shenkar Robert , Batjer H. Hunt , Check Irene J. , Awad Issam A. 
Published: December 2007

Object
Mechanisms of cerebral cavernous malformation (CCM) pathogenesis include genetic predisposition in some cases, but other factors are likely to be involved in lesion proliferation and clinical manifestations. Given the unique antigenic milieu of CCMs, there may be a characteristic immune response in these lesions. We hypothesize that the immunoglobulin (Ig) fraction in CCMs reflects an oligoclonal immune response not present in paired sera from the same patients or in other types of cerebrovascular malformations.

Methods
Surgically excised lesions from five patients with CCMs, three patients with arteriovenous malformations (AVMs), and four normal brain control specimens obtained at autopsy were homogenized and extract tested for IgG clonality by isoelectric focusing in parallel with each patient's serum.

Results
The authors detected B cells in all three lesions examined, and plasmacytes in two out of three lesions examined. Four of five extracts of homogenized CCMs showed an oligoclonal pattern of IgG distinct from the polyclonal pattern seen in those patients' sera. Immununoglobulin G oligoclonality was not seen in AVMs or control brain specimens.

Conclusions
The results of isoelectric focusing studies showed that CCM lesions had oligoclonal patterns of IgG unrelated to peripheral blood contamination, indicating selective synthesis of IgG within the lesions. This finding probably reflects a clonal expansion of B cells and/or plasmacytes in CCMs, an event that might be antigen-driven or a potential marker of inflammation.
Deep brain stimulation electrodes used for staged lesion within the basal ganglia: experimental studies for parameter validation
Authors: Raoul Sylvie , Leduc Dominique , Vegas Thomas , Sauleau Paul , Lozano Andres M. , Vérin Marc , Damier Philippe , Lajat Youenn 
Published: December 2007

Object
Deep brain stimulation (DBS) has been shown to be an effective treatment for various types of movement disorders. High-frequency stimulation is applied to specific brain targets through an implanted quadripolar lead connected to a pulse generator. These leads can be used for creating lesions in the brain. The experimental study reported here was designed to examine the electrical parameters that could be used to create reproducible therapeutic lesions in the brain.

Methods
Egg whites were used to measure the relationship between the electrical parameters (current and voltage) applied through the DBS electrode and the size of coagulum. The authors measured current spread from the electrode contact used for lesioning to the adjacent contact. Similar studies were performed in the pallidum or the thalamus of human cadavers. Modeling of the lesion size was performed with simulation of current density and temperature. The ultrastructure of the electrodes after lesioning was verified by electron microscopy.

Results
Coagulation size increased with time but reached a plateau after 30 seconds. For a given set of electrical parameters, reproducibility of the size of lesions was high. Using constant voltage, lesions were larger in egg whites than in cadaveric brains with a mean length of 5 ± 0.6 mm in egg whites at 40 V, 125 mA, impedance 233 Ω; and 4.0 ± 0.8 mm in cadavers at 40 V, 38 mA, impedance 1333 Ω. Computer modeling indicated negligible current flow to the adjacent, unused electrodes. The electrodes showed no structural alterations on scanning electron microscopy after more than 200 lesions.

Conclusions
Results of this study demonstrate that DBS electrodes can be used to generate lesions reproducibly in the brain. The choice of lesioning parameters must take into account differences in impedance between the test medium (egg whites) and the human brain parenchyma.
Transient facial nerve palsy after topical papaverine application during vestibular schwannoma surgery
Authors: Liu James K. , Sayama Christina M. , Shelton Clough , MacDonald Joel D. 
Published: December 2007

✓Some evidence in the literature supports the topical application of papaverine to the cochlear nerve to prevent internal auditory artery vasospasm and cochlear ischemia as a method of enhancing the ability to preserve hearing during acoustic neuroma surgery. The authors report a case of transient facial nerve palsy that occurred after papaverine was topically applied during a hearing preservation acoustic neuroma removal. A 58-year-old woman presented with tinnitus and serviceable sensorineural hearing loss in her right ear (speech reception threshold 15 dB, speech discrimination score 100%). Magnetic resonance imaging demonstrated a 1.5-cm acoustic neuroma in the right cerebellopontine angle (CPA). A retrosigmoid approach was performed to achieve gross-total resection of the tumor. During tumor removal, a solution of 3% papaverine soaked in a Gelfoam pledget was placed over the cochlear nerve. Shortly thereafter, the quality of the facial nerve stimulation deteriorated markedly. Electrical stimulation of the facial nerve did not elicit a response at the level of the brainstem but was observed to elicit a robust response more peripherally. There were no changes in auditory brainstem responses. Immediately after surgery, the patient had a House–Brackmann Grade V facial palsy on the right side. After several hours, this improved to a Grade I. At the 1-month follow-up examination, the patient exhibited normal facial nerve function and stable hearing.
Intracisternal papaverine may cause a transient facial nerve palsy by producing a temporary conduction block of the facial nerve. This adverse effect should be recognized when topical papaverine is used during CPA surgery.
Postoperative quality of life of patients treated for asymptomatic unruptured intracranial aneurysms
Authors: Yamashiro Shigeo , Nishi Toru , Koga Kazunari , Goto Tomoaki , Muta Daisuke , Kuratsu Jun-ichi , Fujioka Shodo 
Published: December 2007

Object
The aim of this study was to assess the quality of life (QOL) of patients who underwent surgery for asymptomatic unruptured intracranial aneurysms (UIAs).

Methods
The authors assessed QOL in 149 patients who had undergone microsurgical clipping of asymptomatic UIAs. They surveyed these patients using universal methods such as the 36-Item Short Form Health Survey (SF-36) for health-related QOL and the Hospital Anxiety and Depression Scale for anxiety and depression assessments.

Results
The patients' mean scores for each of the eight domains of SF-36 were comparable to those of a Japanese reference population. Analysis of data from the average-QOL and low-QOL subgroups showed that the low-QOL group contained a higher number of patients with preexisting heart diseases and restricted activities of daily living. Operative procedures and complications did not affect QOL.

Conclusions
Because 86% of the patients who underwent surgery manifested a QOL similar to the reference population, the authors suggest that elective surgery for asymptomatic UIAs is a reasonable treatment, especially in patients who are troubled by the risk of rupture. Postoperative decreases in QOL are not invariably attributable to the operation or its associated complications, but may be correlated with other chronic disorders. To select the appropriate treatment for asymptomatic UIAs, neurosurgeons and patients need information on the expected postoperative QOL.
Biological effects of acute pravastatin treatment in patients after aneurysmal subarachnoid hemorrhage: a double-blind, placebo-controlled trial
Authors: Tseng Ming-Yuan , Hutchinson Peter J. , Turner Carole L. , Czosnyka Marek , Richards Hugh , Pickard John D. , Kirkpatrick Peter J. 
Published: December 2007

Object
The authors previously demonstrated that acute pravastatin therapy in patients after aneurysmal subarachnoid hemorrhage (SAH) ameliorates vasospasm-related delayed ischemic neurological deficits. The object of this study was to continue to examine potential mechanisms of these beneficial effects.

Methods
Eighty patients with aneurysmal SAH (age range 18–84 years; time to onset 1.8 ± 1.3 days) were enrolled in a double-blind study and randomized to receive 40 mg of oral pravastatin or placebo daily for as long as 14 days. Daily transcranial Doppler ultrasonography and blood tests every 3 days (including full blood cell counts, coagulation profiles, fasting glucose and lipid profiles, and serum biochemistry) were performed during the trial period.

Results
No significant differences were found in baseline laboratory data between the trial groups. Subsequent measurements during the 14-day trial showed reduced low-density lipoprotein (LDL) cholesterol levels and total/high-density lipoprotein cholesterol ratios between Days 3 and 15 (p < 0.05), and increased D-dimer levels (p < 0.05) on Day 6, in the pravastatin group. Patients who received pravastatin but developed vasospasm had significantly lower baseline LDL cholesterol levels or a less extensive reduction in LDL cholesterol levels (p < 0.05), and greater increases in plasma fibrinogen (p = 0.009) and serum C-reactive protein on Day 3 (p = 0.007), compared with those patients without vasospasm. The reduction in LDL cholesterol levels on Day 3 in the placebo group correlated with the duration of normal cerebral autoregulation on the ipsilateral side of the ruptured aneurysm (p = 0.002).

Conclusions
In addition to functioning through a cholesterol-independent pathway, cerebrovascular protection from acute statin therapy following aneurysmal SAH may also function through cholesterol-dependent mechanisms.