bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-term outcomes of Gamma Knife surgery for cavernous sinus meningioma
Authors: Hasegawa Toshinori , Kida Yoshihisa , Yoshimoto Masayuki , Koike Joji , Iizuka Hiroshi , Ishii Dai
Published: December 2007

Object

The aim of this study was to evaluate long-term outcomes, including tumor control and neurological function, in patients with cavernous sinus meningiomas treated using Gamma Knife surgery (GKS).

Methods

One hundred fifteen patients with cavernous sinus meningiomas, excluding atypical or malignant meningiomas, were treated with GKS between 1991 and 2003. Forty-nine patients (43%) underwent GKS as the initial treatment. The mean tumor volume was 14 cm3, and the mean maximum and margin doses applied to the tumor were 27 and 13 Gy, respectively. The median follow-up period was 62 months. During the follow-up, 111 patients were able to be evaluated with neuroimaging.

Results

The actuarial 5- and 10-year progression-free survival rates were 87 and 73%, respectively. Similarly, the actuarial 5- and 10-year focal tumor control rates were 94 and 92%, respectively. Regarding functional outcomes, 43 patients (46%) experienced some degree of improvement, 40 (43%) remained stable, and 11 (12%) had worse preexisting or newly developed symptoms. Patients who underwent GKS as the initial treatment experienced significant improvement of their symptoms (p = 0.006).

Conclusions

Gamma Knife surgery is a safe and effective treatment over the long term in selected patients with cavernous sinus meningiomas. Tumor progression is more likely to occur from the lesion margin outside the treatment volume. In small to medium-sized tumors, GKS is an excellent alternative to resection, preserving good neurological function. For relatively large-sized tumors, low-dose radiosurgery (≤ 12 Gy) is acceptable for the prevention of tumor progression.
Surgical repair of ulnar nerve lesions caused by gunshot and shrapnel: results in 407 lesions
Authors: Secer Halil Ibrahim , Daneyemez Mehmet , Gonul Engin , Izci Yusuf
Published: December 2007

Object

Ulnar nerve lesions caused by gunshot wounds have rarely been reported in the current literature. The authors describe the outcome after surgical repair of such injuries, and the factors influencing the results of treatment.

Methods

This retrospective study includes 455 patients with 462 ulnar nerve injuries caused by gunshot wounds who were treated at Gulhane Military Medical Academy over a 40-year period. A total of 407 ulnar lesions were surgically repaired at that institution between 1966 and 2005; 237 patients were injured by shrapnel and 218 patients by gunshot. The authors evaluated the motor, sensory, and electrophysiological recovery in these patients, as well as the patients' judgment of the outcome. The authors also tested the effect of repair level, nerve graft length, time to operation, repair technique used, and the presence of coexisting damages in the nerve repair region. The final outcome in these patients was defined as poor, fair, or good on the basis of the British Medical Research Council scores.

Results

A good outcome was noted in 15.06% of patients who underwent high-level repair, 29.60% of patients who underwent intermediate-level repair, and 49.68% of patients after low-level repair. On average, patients with successful outcomes had a significantly shorter time to operation than those with unsuccessful outcomes. The critical period for surgery was within 6 months of injury. Although the optimal graft length was found to be 5 cm, this finding was not statistically significant.

Conclusions

The reported outcome of repairs to ulnar nerves damaged by gunshot has varied in the literature, but there is a consensus that the duration of the interval to surgery, the repair level, and the graft length used influence the outcome of surgical repair for ulnar nerve lesions.
The Hakim programmable valve: reasons for reprogramming failures
Authors: Mauer Uwe Max , Schuler Jens , Kunz Ulrich
Published: December 2007

Object

In patients with hydrocephalus, the pressure settings of a Medos Hakim programmable valve may require adjustments even months after implantation. In some cases, however, adjustment proves to be impossible. The object of this study was to illuminate the reasons for reprogramming failures.

Methods

Data pertaining to the authors' experience with programmable valves at their clinic were obtained through retrospective review of patient records from 1992 to 1998 and prospectively collected from 1998 to 2006. Between 1992 and 2006, 585 Medos Hakim programmable valves were implanted at the authors' center, and reprogramming failure was observed in 12 of these 585 cases. The authors investigated and recorded the reasons for reprogramming failure. In cases in which the valves had to be explanted, the valves were returned to the manufacturer for further investigation and the results were recorded.

Results

In three of the 12 cases of reprogramming failure, the pressure settings could eventually be adjusted by placing the transmitter upside down against the flow direction. In the remaining nine cases, the valve had to be removed, yielding a rate of valve explantation of approximately 1.5% in this series. In two of these nine cases, the valve was found to be rotated longitudinally along its axis. In two cases the ratchet wheel had become loose and in one the radiopaque marker had become dislodged from the baseplate. Extensive deposits were identified macroscopically and microscopically within four explanted valves.

Conclusions

The reasons for failed reprogramming of Codman Medos Hakim valves as described in this article have not been mentioned in the literature so far. Failure of adjusting the pressure setting is a very rare event in a Medos Hakim programmable valve. The programming and adjustment mechanism appears to be very reliable. Valve replacement was required due to failed reprogramming in only a few cases.
Prognostic factors for outcome after transsphenoidal hypophysectomy in dogs with pituitary-dependent hyperadrenocorticism
Authors: Hanson Jeanette M. , Teske Erik , Voorhout George , Galac Sara , Kooistra Hans S. , Meij Björn P.
Published: December 2007

Object

The aim of this study was to determine prognostic factors for outcome after transsphenoidal hypophysectomy in dogs with pituitary-dependent hyperadrenocorticism (PDH).

Methods

One veterinary neurosurgeon performed transsphenoidal hypophysectomies in 181 dogs with PDH over a 12-year period. Survival analysis was performed with the Kaplan–Meier method. Prognostic factors were analyzed with the univariate Cox proportional hazard analysis followed by stepwise multivariate analysis. The log-rank test was used to assess disease-free fractions in three groups categorized according to early postoperative urinary corticoid/creatinine (C/C) ratios.

Results

Multivariate analysis revealed that old age, large pituitary size, and high preoperative concentrations of plasma adrenocorticotropic hormone were associated with an increased risk of PDH-related death. In addition, large pituitary size, thick sphenoid bone, high C/C ratio, and high concentration of plasma α-melanocyte–stimulating hormone (α-MSH) before surgery were associated with an increased risk of disease recurrence in the dogs that went into remission after hypophysectomy. Disease-free fractions were significantly higher in dogs with postoperative urinary C/C ratios in the lower normal range (< 5 × 10−6) than in dogs with postoperative C/C ratios in the upper normal range (5–10 × 10−6).

Conclusions

The results of this study indicate that pituitary size, sphenoid bone thickness, plasma α-MSH concentration, and preoperative level of urinary cortisol excretion are predictors of long-term remission after transsphenoidal hypophysectomy for PDH in dogs. Urinary C/C ratios measured 6 to 10 weeks after surgery can be used as a guide for predicting the risk of tumor recurrence.
Access to cerebrospinal fluid absorption sites by infusion into vascular channels of the skull diploë
Authors: Johnston Kelly D. , Walji Anil H. , Fox Richard J. , Pugh Jeffrey A. , Aronyk Keith E.
Published: December 2007

Object

The purpose of this human cadaver study was to determine whether or not an intraosseous skull infusion would access the superior sagittal sinus (SSS) via intradural venous channels. The diploic space of the skull bone contains a sinusoidal vascular network that communicates with the underlying dura mater. Diploic veins in the parasagittal area connect with endothelium-lined intradural channels in the subjacent dura and ultimately with the dural venous sinuses. A significant proportion of cerebrospinal fluid (CSF) absorption is thought to occur via arachnoid granulations in the region of the SSS and especially along the parasagittal dura where arachnoid granulations are surrounded by intradural venous channels (lateral lacunae). The CSF is likely to be conducted from the subarachnoid space into the venous system via the fine intradural channels making up the lateral lacunae.

Methods

Infusion of vinyl acetate casting material into the diploic space of the human cadaveric skull resulted in complete filling of the lateral lacunae and SSS. Corrosion casting techniques and examination under magnification were used to characterize the anatomical connections between diploic spaces and dural venous sinuses.

Results

Corrosion casting, performed on five formalin-fixed cadavers, clearly showed the anatomical connections between the diploic infusion site and the venous sinuses in the underlying parasagittal dura where some of the CSF is thought to be absorbed.

Conclusions

The diploic vascular channels of the human skull may represent an indirect pathway into the dural venous sinuses. Intraosseous skull infusion may represent another possible strategy for diversion of CSF into the vascular system in the treatment of hydrocephalus.
Superior cerebellar artery aneurysms treated using the sole stenting approach
Authors: Zenteno Marco , Santos-Franco Jorge , Aburto-Murrieta Yolanda , Modenesi-Freitas Jose-María , Ramírez-Guzmán Guadalupe , Gómez-Llata Sergio , Lee Angel
Published: December 2007

✓Endovascular treatment of intracranial aneurysms has evolved since the introduction of detachable coils. Sole stenting is a brand-new technique that has recently emerged as a definitive treatment for saccular or fusiform aneurysms at particular locations. Superior cerebellar artery aneurysms are rare, and few treated cases have been reported. Most of them have been treated surgically, and endovascular cases usually have been managed with occlusion of the parent vessel. The authors report on the first two endovascularly treated cases with complete cure of the aneurysm as well as preservation of the parent vessel and distal circulation via the sole stenting technique. The results together with several aspects of the technique, such as the correction of the angle of the vessel and modification of the shear stress, are discussed.
Loss of visual evoked potential following temporary occlusion of the superior hypophyseal artery during aneurysm clip placement surgery
Authors: Goto Tetsuya , Tanaka Yuichiro , Kodama Kunihiko , Kusano Yoshikazu , Sakai Keiichi , Hongo Kazuhiro
Published: December 2007

✓The authors report a case in which a 62-year-old woman with a history of subarachnoid hemorrhage due to a ruptured aneurysm was found to have a de novo paraclinoid aneurysm in the right internal carotid artery during a routine medical examination. Surgical clip placement was performed via a contralateral pterional approach under visual evoked potential (VEP) monitoring. The superior hypophyseal artery (SHA) was found to originate from the aneurysm body. The artery was temporarily occluded prior to application of the clip to the aneurysm neck. The VEP signal was lost 3 minutes after the SHA was occluded, and the potentials gradually recovered 10 minutes after the artery was released. The disappearance of VEP signal was reproducible with SHA occlusion. The clip was applied to the aneurysm body to preserve the origin of the SHA. The patient did not have any deterioration of vision after surgery.

Intraoperative VEP monitoring can be used to help determine whether the SHA can be sacrificed safely.
Endovascular treatment for bilateral mycotic intracavernous carotid aneurysms
Authors: Yen Pao Sheng , Teo Beng Tiong , Chen Shang Chi , Chiu Tsung Lang
Published: December 2007

✓Bilateral mycotic aneurysms of the intracavernous segment of the internal carotid artery (ICA) are exceedingly rare. The authors present the case of a 46-year-old man with bilateral mycotic intracavernous carotid aneurysms, which were treated with a stent-assisted vessel wall remodeling technique with preservation of the parent arteries. The patient recovered quite satisfactorily after completing the whole course of treatment. Based on an extensive review of the literature, no reported case of bilateral mycotic aneurysm of the intracavernous segment of the ICA has been treated with this mode of endovascular therapy. This mode of treatment could be a therapeutic alternative for intracavernous mycotic aneurysms.
Infusion of intrathecal baclofen for acute withdrawal
Authors: Duhon Bradley S. , Macdonald Joel D.
Published: December 2007

✓ Acute baclofen withdrawal syndrome is a life-threatening situation that demands early recognition and urgent treatment. The current therapy of choice for this syndrome is administration of intravenous benzodiazepines, propofol, and chemical paralytic drugs until the intrathecal system can be restored. The authors present a novel technique for administering baclofen intrathecally using a lumbar drain and a standard patient-controlled analgesia pump (in continuous infusion mode). In one case, this method was used to wean the patient from high-dose intrathecal baclofen treatment. In a second case, this method was used as a temporizing measure until the indwelling pump system could be repaired. In both cases, the patients recovered to their neurological baseline level, and lasting consequences of serious withdrawal were avoided.
Management of bone-invasive, hyperostotic sphenoid wing meningiomas
Authors: Bikmaz Kerem , Mrak Robert , Al-Mefty Ossama
Published: December 2007

Object

The hyperostosis frequently associated with sphenoid wing meningiomas is actual invasion of bone by the tumor. The intracranial portion of the tumor is usually thin with en plaque spread, and the tumor tends to invade the orbit through the superior orbital fissure.

Methods

The authors reviewed the records of 67 patients with sphenoid wing meningiomas who underwent surgery at the University of Arkansas for Medical Sciences between 1994 and 2004. In all 67 cases, the surgery was performed by the senior author. Seventeen of the patients had the distinguishing characteristics of hyperostotic sphenoid wing meningiomas—extensive bone invasion, en plaque dural involvement, and a minimal intracranial mass with minimal orbital involvement. In all patients, hyperostosis was determined on the basis of preoperative neuroimaging. Histopathological evaluation of bone specimens was performed in 14 cases. Estrogen and progesterone receptor expression and Ki 67 labeling were evaluated in all specimens. Chromosome analysis was performed in all tumors resected since 2001 (seven cases). Particular attention was paid to removing all involved bone and dura mater.

Results

Total removal was achieved in 14 cases (82.3%), with only one recurrence (7.1%) over a mean follow-up period of 36 months (range 5–72 months). Radical resection was followed by cranioorbital reconstruction to prevent enophthalmos and to obtain good cosmetic results. No deaths or serious complications occurred in association with surgery. Proptosis was corrected in all cases and visual acuity improved in seven (70%) of 10 cases. Revision of the orbital reconstruction was required because of postoperative enophthalmos (two cases) or restricted postoperative ocular movement (one case).

Conclusions

Sphenoid wing meningiomas frequently invade bone, although such invasion does not represent malignancy. These lesions are generally histologically benign. Total removal with a prospect for cure and visual preservation should be the goal of treatment. This requires extensive drilling of the invaded bone and extensive excision of the involved dura. When the optic canal is involved, it should be decompressed. Extensive bone resection should be followed by cranioorbital reconstruction for good cosmesis and to prevent enophthalmos.
Association of an endogenous inhibitor of nitric oxide synthase with cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage
Authors: Jung Carla S. , Oldfield Edward H. , Harvey-White Judith , Espey Michael G. , Zimmermann Michael , Seifert Volker , Pluta Ryszard M.
Published: December 2007

Object

Delayed cerebral vasospasm after subarachnoid hemorrhage (SAH) may be evoked by the decreased availability of nitric oxide (NO). Increased cerebrospinal fluid (CSF) levels of asymmetric dimethyl-l-arginine (ADMA), an endogenous inhibitor of NO synthase (NOS), have been associated with the course and degree of cerebral vasospasm in a primate model of SAH. In this study, the authors sought to determine if similar changes in CSF ADMA levels are observed in patients with SAH, and whether these changes are associated with NO and NOS metabolite levels in the CSF and the presence of cerebral vasospasm.

Methods

Asymmetric dimethyl-l-arginine, l-arginine, l-citrulline, and nitrite levels were measured in CSF and serum samples collected during the 21-day period after a single aneurysmal SAH in 18 consecutive patients. Samples were also obtained in a control group consisting of seven patients with Chiari malformation Type I and five patients with spontaneous intracerebral hemorrhage without SAH. Vasospasm, defined as a greater than 11% reduction in the anterior circulation vessel diameter ratio compared with the ratio calculated from the initial arteriogram, was assessed on cerebral arteriography performed around Day 7.

Results

In 13 patients with SAH, arteriographic cerebral vasospasm developed. Cerebrospinal fluid ADMA levels in patients with SAH were higher than in those in the control group (p < 0.001). The CSF ADMA level remained unchanged in the five patients with SAH without vasospasm, but was significantly increased in patients with vasospasm after Day 3 (6.2 ± 1.7 μM) peaking during Days 7 through 9 (13.3 ± 6.7 μM; p < 0.001) and then gradually decreasing between Days 12 and 21 (8.8 ± 3.2 μM; p < 0.05). Nitrite levels in the CSF were lower in patients with vasospasm compared to patients without vasospasm (p < 0.03). Cerebrospinal fluid ADMA levels positively correlated with the degree of vasospasm (correlation coefficient [CC] = 0.88, p = 0.0001; 95% confidence interval [CI] 0.74–0.95) and negatively correlated with CSF nitrite levels (CC = −0.55; p = 0.017; 95% CI −0.81 to −0.12).

Conclusions

These results support the hypothesis that ADMA is involved in the progression of cerebral vasospasm. Asymmetric dimethyl-l-arginine and its metabolizing enzymes may be a future target for treatment of cerebral vasospasm after SAH.
Magnetic resonance imaging quantification of compliance and collateral flow in late-onset idiopathic aqueductal stenosis: venous pathophysiology revisited
Authors: Bateman Grant A.
Published: December 2007

Object

Findings in animal models of noncommunicating hydrocephalus have suggested that a reduction in compliance of the superior sagittal sinus, an elevation in venous outflow pressure, and the development of venous collateral flow may be associated with this condition. Although elevated venous pressure is known to cause hydrocephalus in children, this mechanism has fallen out of favor as a theory in adults.

Methods

Twenty-one patients with late-onset idiopathic aqueductal stenosis (LIAS) underwent magnetic resonance imaging with flow quantification measuring the degree of ventricular enlargement, sulcal compression, total blood inflow, superior sagittal/straight sinus outflow, aqueduct flow, arteriovenous delay (AVD), and the extent of collateral venous flow. Data obtained in these patients were compared with those obtained in 21 age-matched control individuals.

Results

There was a reduction in compliance in the patients with LIAS in whom the AVD decreased by 50% (p = 0.01). The arterial inflow and the straight sinus outflow were normal, but the sagittal sinus outflow was reduced by 23% (p = 0.001). This indicated that significant collateral venous outflow pathways were draining blood away from the superficial but not the deep drainage system.

Conclusions

Similar to the animal models, patients with LIAS exhibit a reduced venous compliance and an elevation in venous collateral flow. Together, these findings suggest that an elevation in venous pressure may be associated with this disease process. A review of the literature has indicated that only subtle differences may exist in the pathophysiology among patients with LIAS, normal-pressure hydrocephalus, and idiopathic intracranial hypertension.
Intraoperative real-time contrast-enhanced ultrasound angiography: a new adjunct in the surgical treatment of arteriovenous malformations
Authors: Wang Yi , Wang Yong , Wang Yida , Taniguchi Nobuyuki , Chen Xian-Cheng
Published: December 2007

Object

The goal of this study was to combine the use of ultrasound contrast agents with intraoperative ultrasound techniques to identify intraoperatively a patient's vascular anatomy, including feeding arteries and draining veins of an intracranial arteriovenous malformation (AVM).

Methods

The authors examined 12 consecutive patients with AVMs that had been diagnosed on the basis of preoperative findings on magnetic resonance images and digital subtraction angiograms obtained between September 2003 and December 2005. After each patient had undergone a routine craniotomy, a bolus of contrast agent was injected intravenously, and a real-time microbubble perfusion process was observed to identify the feeding arteries and draining veins of the AVM in a single cross-section. The so-called burst–refill technique was used to sweep the lesion in multiple sections and orientations to obtain information on the surrounding vascular anatomy, after which the findings were compared with those obtained during preoperative imaging.

Results

Intraoperative ultrasonography provided high-quality images in every case. Although plain imaging failed to show an identifiable AVM boundary, color Doppler flow imaging clearly delineated the shape and margin of the AVM. Nevertheless, neither mode of imaging enabled the surgeons to categorically distinguish between feeding and draining vessels.

The real-time perfusion process of microbubbles was first visualized 20 to 30 seconds after the SonoVue bolus injection, and the burst–refill technique made possible identification of the vascular anatomy of malformation lesions in multiple planes.

Conclusions

Using both an ultrasound contrast agent and the burst–refill technique provided a rapid, convenient, and precise way of locating AVM feeding arteries intraoperatively. The combined technique seems warranted in the intraoperative treatment of AVMs.
Endovascular treatment of pericallosal aneurysms
Authors: Nguyen Thanh N. , Raymond Jean , Roy Daniel , Chagnon Miguel , Weill Alain , Iancu-Gontard Daniela , Guilbert Francois
Published: December 2007

Object

Pericallosal artery aneurysms are uncommon. Their treatment strategy, surgical or endovascular, will present specific challenges. The objective of the study was to compare risks of coil therapy and the recurrence rate of pericallosal artery aneurysms with aneurysms in other intradural locations.

Methods

The authors examined data that were stored in a prospectively collected database for pericallosal artery aneurysms in patients who underwent coil placement between 1992 and 2005. Hemorrhagic and thromboembolic complications as well as clinical and angiographic outcomes were reviewed. Angiographically documented recurrences were classified as minor or major. These lesions were compared with a historical cohort of non–pericallosal artery aneurysms in patients who underwent coil therapy between 1992 and 2002. The known risk factors for recurrence and procedure-related hemorrhagic complications were evaluated in both groups to assess baseline imbalances.

Results

During a 13-year period, 25 pericallosal artery aneurysms were treated with coils in 25 patients. The non–pericallosal artery lesion group included 488 aneurysms of which 344 underwent follow-up imaging. Procedure-related perforations were more frequent for pericallosal artery aneurysms than those in other intradural locations (three of 25 compared with eight of 476, respectively; risk ratio 7.1, 95% confidence interval [CI] 2.1–22.5, p = 0.03). Follow-up imaging studies (obtained at a mean 28 months) were available for 19 patients with pericallosal artery aneurysms. The recurrence rate was not significantly higher in these patients (22.9/100 person–years of observation) than in those with non–pericallosal artery aneurysms (17.9/100 person–years of observation) (incidence rate ratio 1.3, 95% CI 0.6–2.4, p = 0.46).

Conclusions

Pericallosal artery aneurysms were associated with significantly higher periprocedural rupture than non–pericallosal artery lesions. No significant intergroup difference was found for aneurysm recurrence.
Cortical and subcortical brain shift during stereotactic procedures
Authors: Elias W. Jeffrey , Fu Kai-Ming , Frysinger Robert C.
Published: December 2007

Object

The success of stereotactic surgery depends upon accuracy. Tissue deformation, or brain shift, can result in clinically significant errors. The authors measured cortical and subcortical brain shift during stereotactic surgery and assessed several variables that may affect it.

Methods

Preoperative and postoperative magnetic resonance imaging volumes were fused and 3D vectors of deviation were calculated for the anterior commissure (AC), posterior commissure (PC), and frontal cortex. Potential preoperative (age, diagnosis, and ventricular volume), intraoperative (stereotactic target, penetration of ventricles, and duration of surgery), and postoperative (volume of pneumocephalus) variables were analyzed and correlated with cortical (frontal cortex) and subcortical (AC, PC) deviations.

Results

Of 66 cases, nine showed a shift of the AC by more than 1.5 mm, and five by more than 2.0 mm. The largest AC shift was 5.67 mm. Deviation in the x, y, and z dimensions for each case was determined, and most of the cortical and subcortical shift occurred in the posterior direction. The mean 3D vector deviations for frontal cortex, AC, and PC were 3.5 ± 2.0, 1.0 ± 0.8, and 0.7 ± 0.5 mm, respectively. The mean change in AC–PC length was −0.2 ± −0.9 mm (range −4.28 to 1.66 mm). The volume of postoperative pneumocephalus, assumed to represent cerebrospinal fluid (CSF) loss, was significantly correlated with shift of the frontal cortex (r = 0.640, 64 degrees of freedom, p < 0.001) and even more strongly with shift of the AC (r = 0.754, p < 0.001). No other factors were significantly correlated with AC shift. Interestingly, penetration of the ventricles during electrode insertion, whether unilateral or bilateral, did not affect volume of pneumocephalus.

Conclusions

Cortical and subcortical brain shift occurs during stereotactic surgery as a direct function of the volume of pneumocephalus, which probably reflects the volume of CSF that is lost. Clinically significant shifts appear to be uncommon, but stereotactic surgeons should be vigilant in preventing CSF loss.
Transcriptional regulation of inflammatory and extracellular matrix–regulating genes in cerebral arteries following experimental subarachnoid hemorrhage in rats
Authors: Vikman Petter , Ansar Saema , Edvinsson Lars
Published: December 2007

Object

Subarachnoid hemorrhage (SAH) results in the expression of inflammatory and extracellular matrix (ECM)–related genes and various G protein–coupled receptors. In the present study, the authors evaluated the time course and sequence of the transduction pathways, p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase–1 and 2 (ERK1/2), and associated transcription factor activation as well as gene regulation and associated protein levels.

Methods

Subarachnoid hemorrhage was induced in rats by injecting 250 μl of blood into the suprachiasmatic cistern, and gene regulation in the cerebral arteries was examined at various points in time following SAH by using quantitative polymerase chain reaction (PCR) and immunohistochemistry.

Results

Immunohistochemical findings demonstrated that SAH phosphorylates and activates p38 and ERK1/2 as well as the downstream transcription factors Elk-1 and activating transcription factor–2. The pattern of activation consists of a rapid phase within the first few hours and a late phase that occurs from 24 to 48 hours. Activation is followed by an increase in the transcription of the inflammatory and ECM-related genes (IL6, TNFα, IL1β, CXCL1, CXCL2, CCL20, MMP8, MMP9, MMP13, and iNOS), as demonstrated using real-time PCR. For MMP13 and iNOS, the changes in transcription were translated into functional proteins, as revealed on immunohistochemistry.

Conclusions

Activation of the p38 and ERK1/2 signaling pathways and their downstream transcription factors can explain the increase in the transcription of the genes studied. This increase and the subsequent augmentation in protein levels suggest that the inflammatory response may in part explain the remodeling that occurs in cerebral arteries following SAH.
Hyperhidrosis due to deep brain stimulation in a patient with essential tremor
Authors: Diamond Alan , Kenney Christopher , Almaguer Michael , Jankovic Joseph
Published: December 2007

✓The authors present a unique case of hyperhidrosis as a side effect of a misplaced deep brain stimulation (DBS) electrode near the ventrointermedius (Vim) nucleus in a patient with essential tremor. Magnetic resonance imaging of the brain showed electrode placement in the left anterior thalamus traversing the hypothalamus. High-frequency electrical stimulation possibly resulted in unilateral activation of the efferent sympathetic pathways in the zona incerta. Although a rare complication, hypothalamic dysfunction may occur as a stimulation-related side effect of Vim-DBS.
Endoscopic endonasal clipping of an unsecured superior hypophyseal artery aneurysm
Authors: Kassam Amin B. , Gardner Paul A. , Mintz Arlan , Snyderman Carl H. , Carrau Ricardo L. , Horowitz Michael
Published: December 2007

✓Paraclinoidal aneurysms, especially superior hypophyseal artery (SHA) aneurysms (with medial projection), can be challenging to access via a pterional craniotomy and damage to the optic nerve can occur during surgery. The authors have previously reported on endonasal clipping and aneurysmorrhaphy of a vertebral artery aneurysm following proximal and distal protection of the aneurysm using partial coil embolization. To the best of the authors' knowledge no unprotected aneurysm has been clipped using an endonasal approach.

The 56-year-old woman in this report was found to have two unruptured aneurysms: an anterior communicating artery (ACoA) aneurysm and an SHA aneurysm. An endoscopic endonasal, transplanar–transsellar approach was used to successfully clip the SHA aneurysm. Proximal and distal control was obtained endonasally prior to successful clip occlusion of the aneurysm. The ACoA aneurysm was clipped via a pterional craniotomy during the same anesthetic session. This report shows that it is possible to successfully clip a medially projecting, paraclinoidal aneurysm using an endonasal approach. Such cases must be chosen with extreme caution and only performed by surgeons with significant experience with both endoscopic endonasal approaches and neurovascular surgery.
Naval aviation and neurosurgery: traditions, commonalities, and lessons learned
Authors: Quest Donald O.
Published: December 2007

✓In his presidential address to the American Association of Neurological Surgeons, the author recounts lessons he learned while training to be a Naval Aviator and later a neurosurgeon. He describes his life as an aviator and neurosurgeon, compares naval aviation and neurosurgery, and points out lessons that neurosurgery can learn from naval aviation.
Early ischemic lesion on computed tomography: predictor of poor outcome among survivors of aneurysmal subarachnoid hemorrhage
Authors: Siironen Jari , Porras Matti , Varis Joona , Poussa Kristiina , Hernesniemi Juha , Juvela Seppo
Published: December 2007

Object

Identifying ischemic lesions after subarachnoid hemorrhage (SAH) is important because the appearance of these lesions on follow-up imaging correlates with a poor outcome. The effect of ischemic lesions seen on computed tomography (CT) scans during the first days of treatment remains unknown, however.

Methods

In 156 patients with SAH, clinical course and outcome, as well as the appearance of ischemic lesions on serial CT scans, were prospectively monitored for 3 months. At 3 months after SAH, magnetic resonance imaging was performed to detect permanent lesions that had not been visible on CT.

Results

Of the 53 patients with no lesions on any of the follow-up CT scans, four (8%) had a poor outcome. Of the 52 patients with a new hypodense lesion on the first postoperative day CT, 23 (44%) had a poor outcome. Among the remaining 51 patients with a lesion appearing later than the first postoperative morning, 10 (20%) had a poor outcome (p < 0.001). After adjusting for patient age; clinical condition on admission; amounts of subarachnoid, intracerebral, and intraventricular blood; and plasma glucose and D-dimer levels, a hypodense lesion on CT on the first postoperative morning was an independent predictor of poor outcome after SAH (odds ratio 7.27, 95% confidence interval 1.54–34.37, p < 0.05).

Conclusions

A new hypodense lesion on early postoperative CT seems to be an independent risk factor for poor outcome after SAH, and this early lesion development may be more detrimental to clinical outcome than a later lesion occurrence.
Microvascular decompression for primary trigeminal neuralgia: long-term effectiveness and prognostic factors in a series of 362 consecutive patients with clear-cut neurovascular conflicts who underwent pure decompression
Authors: Sindou Marc , Leston José , Decullier Evelyne , Chapuis François
Published: December 2007

Object

The purpose of this study was to evaluate the long-term efficacy of microvascular decompression (MVD) and to identify the factors affecting outcome in patients treated for primary trigeminal neuralgia (TN). Only the cases with a clear-cut neurovascular conflict (vascular contact and/or compression of the root entry zone of the trigeminal nerve) found at surgery and treated with “pure” MVD (decompression of the root without any additional lesioning or cutting of the adjacent rootlets) were retained.

Methods

The study included 362 patients who were followed up over a period of 1 to 18 years (median follow-up 7.2 years). A Kaplan–Meier survival analysis was generated at 1 and 15 years of follow-up for all of the considered factors. According to Kaplan–Meier analysis, the success rate (defined as pain-free patients without any medication) was 91% at 1 year and estimated to be 73.38% after 15 years of follow-up.

Results

None of the following patient-related factors played any significant role in prognosis: sex, patient age at surgery, history of systemic hypertension, duration of neuralgia before surgery, or history of failed trigeminal surgery. Patients with atypical neuralgia (a baseline of permanent pain) had the same outcome as those with a typical (purely spasmodic) presentation. In addition, the side and topography of the trigeminal nerve did not play a role, whereas involvement of all three divisions of the nerve had a negative effect on outcome. Concerning anatomical factors, neither the type of the compressive vessel nor its location along or around the root was found to be significant. However, the severity of compression was important—the more severe the degree of compression, the better the outcome (p = 0.002). The authors also found that presence of focal arachnoiditis had a negative influence on outcome (p = 0.002).

Conclusions

Pure MVD can offer patients affected by a primary TN a 73.38% probability of long-term (15 years) cure of neuralgia. The presence of a clear-cut and marked vascular compression at surgery (and possibly—although not yet reliably—on preoperative magnetic resonance imaging) is the guarantee of a higher than 90% success rate.
Endoscopically assisted decompression of the suprascapular nerve in the supraspinous fossa: a cadaveric feasibility study
Authors: Tubbs R. Shane , Loukas Marios , Shoja Mohammadali M. , Spinner Robert J. , Middlebrooks Erik H. , Stetler William R. , Acakpo-Satchivi Leslie , Wellons John C. , Blount Jeffrey P. , Oakes W. Jerry
Published: December 2007

Object

The suprascapular nerve may become entrapped as it travels deep to the suprascapular ligament, necessitating decompression. The present study was performed to verify the feasibility of a minimally invasive, endoscopically assisted technique for decompressing the suprascapular nerve in the supraspinous fossa.

Methods

The authors performed dissection and decompression of the suprascapular ligament using an endoscopically assisted technique via a 3-cm skin incision in 10 adult cadavers (20 sides). Measurements were also made of the depth from the skin to the suprascapular ligament.

Results

A mean depth of 4 cm was necessary to reach the suprascapular ligament from the skin surface. With the authors' approach, no obvious injury occurred to the suprascapular or other vicinal neurovascular structures (such as the spinal accessory nerve and suprascapular vessels).

Conclusions

The results of this cadaveric study demonstrate that access to the suprascapular nerve can be obtained endoscopically via a small suprascapular incision. This approach obviates a large incision, entry into the glenohumeral joint, and reduces the risk of spinal accessory nerve injury in the posterior cervical triangle, or atrophy of the trapezius or supraspinatus muscles from a standard larger dissection. To the authors' knowledge an endoscopically assisted approach to decompressing the suprascapular nerve as it courses deep to the suprascapular ligament has not been reported previously.
The role of evaluation methods in the assessment of peripheral nerve regeneration through synthetic conduits: a systematic review
Authors: Vleggeert-Lankamp Carmen L. A. M.
Published: December 2007

Object

A number of evaluation methods that are currently used to compare peripheral nerve regeneration with alternative repair methods and to judge the outcome of a new paradigm were hypothesized to lack resolving power. This would too often lead to the conclusion that the outcome of a new paradigm could not be discerned from the outcome of the current gold standard, the autograft. As a consequence, the new paradigm would incorrectly be judged as successful.

Methods

An overview of the methods that were used to evaluate peripheral nerve regeneration after grafting of the rat sciatic nerve was prepared. All articles that were published between January 1975 and December 2004 and concerned grafting of the rat sciatic nerve (minimum graft length 5 mm) and in which the experimental method was compared with an untreated or another grafted nerve were included. The author scored the presence of statistically significant differences between paradigms.

Results

Evaluation of nerve fiber count, nerve fiber density, N-ratio, nerve histological success ratio, compound muscle action potential, muscle weight, and muscle tetanic force are methods that were demonstrated to have resolving power.

Conclusions

A number of evaluation methods are not suitable to demonstrate a significant difference between experimental paradigms in peripheral nerve regeneration. It is preferable to apply a combination of evaluation methods with resolving power to evaluate nerve regeneration properly.
Sutureless nonocclusive bypass surgery in combination with an expanded polytetrafluoroethylene graft
Authors: Bremmer Jochem P. , Verweij Bon H. , van der Zwan Albert , Reinert Michael M. , Mansvelt Beck Hendricus J. , Tulleken Cornelis A. F.
Published: December 2007

Object

Cerebral aneurysms that cannot be treated by clip or coil placement can be treated with high-flow bypass surgery using techniques such as the excimer laser–assisted nonocclusive anastomosis (ELANA). To simplify the technique, a sutureless ELANA (SELANA) was developed in combination with an expanded polytetrafluoroethylene (ePTFE) graft.

Methods

In 18 rabbits a bypass was constructed on the abdominal aorta using the SELANA technique with an ePTFE graft, resulting in 18 bypasses and 36 anastomoses. Short-term effects were analyzed in the first 2 weeks and at 2 and 3 months after the procedure. Patency was evaluated using quantitative ultrasound flowmetry. The anastomotic sites were studied using scanning electron microscopy.

Results

Construction of the bypass using the SELANA technique was easier and faster (15–25 minutes) compared with bypasses made with the ELANA technique (> 90 minutes). At the end of follow-up, 16 of 18 bypasses were patent. Of 36 SELANA anastomoses, 32 could be completed without short temporary occlusion of the recipient vessel. Scanning electron microscopy showed complete coverage of all anastomoses with neointimal repair tissue after 10 days.

Conclusions

The SELANA technique provides further advantages over the conventional ELANA technique in ease of use and shortening of procedure time. The patency rate in this series was 89% and neointima repair tissue at the anastomosis site was complete after 10 days. Further experimental studies of the long-term patency and safety of this technique are necessary before clinical application.
“Internal cross-clamping” for symptomatic internal carotid artery thrombus
Authors: Ecker Robert D. , Tummala Ramachandra P. , Levy Elad I. , Hopkins L. Nelson
Published: December 2007

✓Both carotid endarterectomy and carotid artery stent placement with filter embolic protection present a higher risk for patients with internal carotid artery (ICA) lesions containing intraluminal thrombus. Despite the risk associated with intervention, patients with symptomatic intraluminal thrombus who were enrolled in the North American Symptomatic Endarterectomy Trial did better with surgical than medical treatment. We describe the novel use of an endovascular “internal cross-clamping” technique in two patients with symptomatic intraluminal thrombus in the ICA. A 57-year-old woman presented with a history of multiple episodes of left upper-extremity numbness, mild dysarthria, and agraphia occurring over the previous 24 hours. Cranial magnetic resonance imaging revealed a scattered watershed infarction of the right hemisphere and a critical stenosis of the right ICA. An 81-year-old man awoke with hemiplegia and inability to follow commands after undergoing a complicated carotid endarterectomy. Computed tomographic perfusion imaging demonstrated an increased time to peak in the left middle cerebral territory, and emergent angiography demonstrated both intimal flaps and thrombus in the endarterectomy bed. The lesions in both patients were treated with endovascular stent placement using both proximal and distal flow occlusion—a functional “internal cross-clamping”—for embolic protection. To our knowledge, this is the first report of internal trapping and stent placement for symptomatic carotid stenosis containing intraluminal thrombus. This treatment strategy should be added to the armamentarium of endovascular surgeons in selected patients with symptomatic carotid intraluminal thrombus.
Paroxysmal otalgia due to compression of the intermediate nerve: a distinct syndrome of neurovascular conflict confirmed by neuroimaging
Authors: Sakas Damianos E. , Panourias Ioannis G. , Stranjalis George , Stefanatou Maria P. , Maratheftis Nikos , Bontozoglou Nikos
Published: December 2007

✓The authors present the case of a 52-year-old female patient with a 6-year history of intractable paroxysmal otalgia. Preoperative magnetic resonance (MR) angiography demonstrated an anterior inferior cerebellar artery loop compressing the intermediate nerve in the seventh/eighth cranial nerve complex inside the internal auditory canal. The pain resolved completely after a microvascular decompression via a retromastoid craniotomy. To the best of the authors' knowledge, the combined neuroimaging and intraoperative findings of this case provide a unique demonstration that vascular compression of the intermediate nerve can be the exclusive cause of paroxysmal otalgia. Magnetic resonance imaging and MR angiography can establish the causative mechanism and distinguish this otalgia due to vascular compression of the intermediate nerve from other pain syndromes that are designated as geniculate neuralgia (GN). The present case indicates that intermediate nerve neuralgia is a distinct syndrome of neurovascular conflict and a variant of GN. The causative classification of GN should be reexamined with the use of advanced MR imaging.
Optimizing computed tomography to reduce artifacts from titanium aneurysm clips: an in vitro study
Authors: Mamourian Alexander C. , Pluta Daniel J. , Eskey Clifford J. , Merlis Anthony L.
Published: December 2007

Object

At many institutions digital subtraction angiography remains the standard imaging procedure for the postoperative evaluation of patients following placement of a cerebral aneurysm clip largely because of the artifacts produced by the clip on computed tomography (CT). The authors evaluated the effect of various imaging parameters on the quality of 3D reconstructions from CT scans while imaging a phantom to optimize the CT angiograms.

Methods

Using multidetector CT scanners with submillimeter detector collimation (0.625 mm), the authors scanned a silicone phantom with attached commercial aneurysm clips. Slice thickness, reconstruction overlap, kilovolt level, milliampere level, and pitch were varied. Neuroradiologists, who were blinded to the scanning parameters, rated the reconstructions for image quality and artifact reduction.

Results

Images of the titanium clip using 140 kV and 380 mA with 0.625-mm overlapping reconstructed slices provided excellent 3D visualization of both the clip and the aneurysm model, even when using two adjacent clips.

Conclusions

Overlapping reconstructions combined with thin-section acquisition can provide detailed images of titanium clips and surrounding tissues without the use of low-pitch values.