bluuebunny/crossref_metadata_2025 huggingface dataset:
Diagnostic and microsurgical presentation of intracranial angiolipomas
Authors: Pirotte Benoît , Krischek Boris , Levivier Marc , Bolyn Serge , Brucher Jean-Marie , Brotchi Jacques
Published: June 2009

✓ Angiolipomas (ALs) are hamartomas composed of abnormally differentiated vessels and mature adipose tissue. Although they are most commonly found in peripheral tissues, ALs sometimes grow in the spinal epidural space. Intracranial ALs (ICALs) are rare: only seven cases have been reported in the literature. The authors describe the case of a 70-year-old woman who presented with ocular symptoms from a clinically and radiologically progressing parasellar ICAL. The radiological as well as the microsurgical findings are illustrated and compared with the seven previously published cases. The most frequent location of ALs is the skull base, especially the parasellar region. Other ICALs were diagnosed as components of cerebral arteriovenous malformations and were not symptomatic by themselves. Neuroradiological studies of ICALs usually demonstrate the characteristics of both adipose and vascular tissues. However, a review of the literature shows that the diagnosis had not been suspected preoperatively in any of the cases. Operative descriptions emphasize that most neurosurgeons were caught off guard by the profuse bleeding and the unusual relationship of this unexpected lesion to the cavernous sinus, so that removal was rarely complete. The authors conclude that preoperative diagnosis of ICALs is achievable based on magnetic resonance analysis, which should help optimize the microsurgical management of these lesions.
Multiple appearing and vanishing aneurysms: primary angiitis of the central nervous system
Authors: Nishikawa Misao , Sakamoto Hiroaki , Katsuyama Junsuke , Hakuba Akira , Nishimura Shuro
Published: June 2009

✓ The authors present the case of a patient with ischemic episodes and recurrent intracerebral hemorrhages probably caused by primary angiitis of the central nervous system (CNS). An initial angiogram revealed multiple cerebral artery aneurysms as well as vascular wall irregularity; a second angiogram obtained 2 years later, however, did not demonstrate the previous aneurysms but instead showed new ones together with stenosis. Based on the histopathological findings and clinical course in this case, the multiple aneurysms appear to have been induced by vascular wall fragility and subsequent self-repair resulting from primary angiitis of the CNS. The authors present the histological and clinical characteristics of this unusual case of granulomatous, necrotizing CNS vasculitis.
Large glial cyst of the pineal gland: a possible growth mechanism
Authors: Kang Hyun-Seung , Kim Dong Gyu , Han Dae Hee
Published: June 2009

✓ The authors report on a patient who presented with a large symptomatic glial cyst of the pineal gland communicating with the third ventricle. The hole between the ventricle and the cyst, suspected on magnetic resonance images, was found at surgery. The to-and-fro flow mechanism is considered to be involved in the pathogenesis of growth in this unusual large glial cyst of the pineal gland, although this mechanism cannot be applied universally.
Stereotactic brachytherapy for a cystic metastatic brain tumor in the midbrain
Authors: Matsumoto Kengo , Tada Eiji , Tamesa Nobuo , Tomita Susumu , Ohmoto Takashi
Published: June 2009

✓ The authors report a rare case of a cystic metastasis in the midbrain that was successfully treated by brachytherapy following stereotactic biopsy and aspiration of the intratumoral cyst. Stereotactic aspiration of cystic lesions can lead to clinical improvement and brachytherapy prevents cyst recurrence.

A 46-year-old man was referred to the authors' institution with a 2-month history of a left hemisensory disturbance and a 1-month history of progressive hemiparesis. Magnetic resonance (MR) imaging revealed a ring-enhancing cystic mass in the midbrain. On the basis of this imaging study, a differential diagnosis that included brainstem abscess, glioma, and metastatic tumor was made. Magnetic resonance imaging—guided stereotactic biopsy and aspiration of the intratumoral cyst were performed, yielding 5 ml of yellowish-white fluid. Histological examination provided a diagnosis of adenocarcinoma. During the surgery, a catheter through which brachytherapy would be delivered was inserted at a predetermined target. The patient's left hemiparesis and sensory disturbance were markedly improved and brachytherapy was begun 2 days postoperatively. Three radioactive isotopes composed of iridium-192 were implanted to irradiate the tumor tissue. The total dose at the tumor periphery was 30 Gy, which was administered over 100 hours. External-beam radiotherapy (20 Gy) was added after completion of the brachytherapy. At discharge from the hospital, the patient was alert and all his neurological symptoms had resolved. Follow-up MR imaging revealed stabilization of the cyst and no recurrence of the tumor. The patient is alive and well 18 months following the brachytherapy. This case suggests that brachytherapy can delay cyst recurrence, suppress tumor growth, and prolong survival in patients with cystic brainstem metastasis.
Postlaminectomy cervical spinal cord compression demonstrated by dynamic magnetic resonance imaging
Authors: Morimoto Tetsuya , Ohtsuka Hiroyuki , Sakaki Toshisuke , Kawaguchi Masahiko
Published: June 2009

✓ This 32-year-old man had undergone C3–7 laminectomy for posttraumatic cervical myelopathy associated with spinal canal stenosis. He developed recurrent myelopathy 5 years after the initial operation. Dynamic magnetic resonance (MR) imaging of the cervical spine demonstrated spinal cord compression with diffuse canal stenosis while the neck was in the extended position, whereas no significant stenosis was visualized in the neutral position. Sagittal and axial MR images of the affected levels demonstrated striking changes in the cervical spinal cord configuration. Because of an associated hard osteophyte formation and protruded disc, as well as a hypertrophied posterior longitudinal ligament, an anterior decompression and fusion with plate fixation were performed from C-4 to C-7. The postoperative course was uneventful, with subsequent neurological improvement. It is concluded that dynamic MR imaging aids the search for the cause of recurrent postlaminectomy cervical myelopathy after initial improvement following decompressive surgery.
Failure of transodontoid screw fixation
Authors: Etebar Shahin , Cahill David W.
Published: June 2009

✓ Anterior odontoid screw fixation is being performed with increasing frequency and may currently be the treatment of choice for Type II and selected Type III odontoid fractures, because it is the only surgical fusion that preserves C1–2 motion. Typically patients are immobilized postoperatively in a simple cervical collar. The authors present a case of postoperative fracture of the anterior body of the axis secondary to screw dislocation 5 weeks after single anterior odontoid screw osteosynthesis. Possible reasons for this rare complication and its implications for the technique are discussed.
Hydrocephalus and craniosynostosis
Authors: Cinalli Giuseppe , Sainte-Rose Christian , Kollar Eve Marie , Zerah Michel , Brunelle Francis , Chumas Paul , Arnaud Eric , Marchac Daniel , Pierre-Kahn Alain , Renier Dominique
Published: June 2009

Object.A retrospective study of 1727 cases of craniosynostosis was undertaken to determine the interrelationship between abnormal cerebrospinal fluid (CSF) hydrodynamics and craniosynostosis.

Methods.The patients were divided into two groups: nonsyndromic craniosynostosis and syndromic craniosynostosis. Cases of occipital plagiocephaly without suture synostosis and cases of shunt-induced craniosynostosis were excluded from the study. The majority of patients (1297) were treated surgically for their cranial deformity; 95% of these patients had a postoperative follow-up review period lasting 5 years. Clinical and radiographic charts covering the time from presentation through the follow-up period were reviewed.

Conclusions.Abnormal intracranial CSF hydrodynamics was found in 8.1% of the patients (3.4% of whom had received shunts and 4.5% of whom had not). Three types of CSF hydrodynamic disturbance were observed: progressive hydrocephalus with ventricular dilation, nonprogressive ventriculomegaly, and dilation of the subarachnoid spaces. Hydrocephalus occurred much more frequently in patients with syndromic craniosynostosis (12.1%) than in those with isolated craniosynostosis (0.3%). In fact, patients with kleeblattschädel exhibited hydrocephalus as a constant feature and patients with Crouzon's syndrome were far more likely to have hydrocephalus than those with other syndromes. In Apert's syndrome, ventricular dilation occurred very frequently, but it was almost always nonprogressive in nature. In most cases of syndromic craniosynostosis, venous sinus obstruction and/or chronic tonsillar herniation were found. Their role in the pathophysiology of hydrocephalus in craniosynostosis is discussed.
Surgical treatment of spontaneous spinal cerebrospinal fluid leaks
Authors: Schievink Wouter I. , Morreale Vittorio M. , Atkinson John L. D. , Meyer Fredric B. , Piepgras David G. , Ebersold Michael J.
Published: June 2009

Object. Spontaneous spinal cerebrospinal fluid (CSF) leaks are an increasingly recognized cause of intracranial hypotension and may require neurosurgical intervention. In the present report the authors review their experience with the surgical management of spontaneous spinal CSF leaks.

Methods. Between 1992 and 1997, 10 patients with spontaneous spinal CSF leaks and intracranial hypotension were treated surgically. The mean age of the seven women and three men was 42.3 years (range 22–61 years). Preoperative imaging showed a single meningeal diverticulum in two patients, a complex of diverticula in one patient, and a focal CSF leak alone in seven patients. Surgical exploration in these seven patients demonstrated meningeal diverticula in one patient; no clear source of CSF leakage could be identified in the remaining six patients. Treatment consisted of ligation of the diverticula or packing of the epidural space with muscle or Gelfoam. Multiple simultaneous spinal CSF leaks were identified in three patients.

Conclusions. All patients experienced complete relief of their headaches postoperatively. There has been no recurrence of symptoms in any of the patients during a mean follow-up period of 19 months (range 3–58 months; 16 person-years of cumulative follow up). Complications consisted of transient intracranial hypertension in one patient and leg numbness in another patient.

Although the disease is often self-limiting, surgical treatment has an important role in the management of spontaneous spinal CSF leaks. Surgery is effective in eliminating the headaches and the morbidity is generally low. Surgical exploration for a focal CSF leak, as demonstrated on radiographic studies, usually does not reveal a clear source of the leak. Some patients may have multiple simultaneous CSF leaks.
Evaluation of intercostal to musculocutaneous nerve transfer in reconstructive brachial plexus surgery
Authors: Malessy Martijn J. A. , Thomeer Ralph T. W. M.
Published: June 2009

Object.Direct coaptation of intercostal nerves (ICNs) to the musculocutaneous (MC) nerve was performed to restore elbow flexion in 25 patients with brachial plexus root avulsions.

Methods.Seventy-five ICNs were transected as close as possible to the sternum to obtain sufficient length and then tunneled to the axilla and coapted to the MC nerve. Direct coaptation was achieved in 95% of ICNs, and functional elbow flexion was regained in 64% of the patients. The results were compared with several reported transfer techniques in which either an ICN or other donor nerves were used.

Conclusions.Direct coaptation was equally effective and more straightforward than transfers involving interposition of grafts. The use of alternative donors such as the accessory nerve carries inherent disadvantages compared with the use of ICNs, and the results are not substantially better. Direct ICN—MC nerve transfer is a valuable reconstructive procedure.
Is routine transcranial Doppler ultrasound monitoring useful in the management of subarachnoid hemorrhage?
Authors: Wardlaw Joanna M. , Offin Ruth , Teasdale Graham M. , Teasdale Evelyn M.
Published: June 2009

Object. In this prospective observational study, the authors assess the impact of routine transcranial Doppler (TCD) ultrasound monitoring on the diagnosis, management, and outcome of delayed ischemic neurological deficit complicating subarachnoid hemorrhage (SAH).

Methods. Over a 10-month period 186 patients admitted to a regional neurosciences center were included in the study. Three times a week, routine TCD examinations performed by neuroradiographers made an important positive contribution to the diagnosis of delayed ischemic neurological deficit in 72% of patients with this complication and led to altered management for the benefit of the patient in 43%. In 9% of patients with recent SAH, it was believed that the outcome might have been better if the TCD result had been acted upon appropriately. The TCD results did not adversely influence management or outcome and were generally accurate when compared with those obtained on angiography.

Conclusions. A routine TCD service provided by neuroradiographers is accurate and useful in diagnosing and managing elevated blood velocities and ischemic neurological deficit following SAH. In addition, it is possible that if the information gleaned from TCD findings was used more often in patient management, outcome might be improved; however, a randomized controlled trial is necessary to assess both these points definitively.
Arteriovenous malformations in the basal ganglia and thalamus: management and results in 101 cases
Authors: Sasaki Tomio , Kurita Hiroki , Saito Isamu , Kawamoto Shunsuke , Nemoto Shigeru , Terahara Atsuro , Kirino Takaaki , Takakura Kintomo
Published: June 2009

Object. Because arteriovenous malformations (AVMs) in the basal ganglia and thalamus are difficult to treat, the authors conducted a retrospective study to determine the best management strategy for these lesions.

Methods. The authors reviewed the management and outcome in 101 patients with AVMs treated between 1971 and 1995. In 15 conservatively treated patients, hemorrhage occurred in 71.4% (annual rate 11.4%), and the morbidity and mortality rates were 7.1% and 42.9%, respectively, during a mean follow-up period of 6.6 years. Total microsurgical resection was performed in 15 patients with no mortality resulting, but motor function deteriorated permanently in three of them (20%). Postoperative morbidity correlated well with the location of the AVM and with preoperative motor function. In cases of lenticular AVMs without motor weakness, a postoperative decrease in motor function was significantly more common than in the remaining patients. In patients with motor weakness before surgery, AVMs in the thalamus or caudate nucleus were successfully resected. Among 66 patients treated with gamma knife radiosurgery, three had permanent radiation-induced neurological deficits, and three others experienced bleeding (new bleeding in one case and rebleeding in two). The treatment-associated morbidity rate was 6.7%, and the actuarial rate of complete obliteration was 85.7% at 2.5 years. In five patients treated with embolization alone, the morbidity and mortality rates associated with the procedure or bleeding were 40% and 20%, respectively. The morbidity and mortality rates in the pre—gamma knife era were 22.2% and 22.2%, whereas those for the post-gamma knife era are currently 10.4% and 1.5%, respectively.

Conclusions. These results indicate that conservatively treated AVMs are more likely to bleed and thus produce a high incidence of patient mortality. Multimodal treatment including radiosurgery, microsurgery, and embolization improved clinical outcomes by making it possible to treat difficult cases successfully.
Role of ferrous iron chelator 2,2′-dipyridyl in preventing delayed vasospasm in a primate model of subarachnoid hemorrhage
Authors: Horky Laura L. , Pluta Ryszard M. , Boock Robert J. , Oldfield Edward H.
Published: June 2009

Object.Oxyhemoglobin (HbO2) causes vasospasm after subarachnoid hemorrhage (SAH). The most likely spasmogenic component of HbO2is iron. Various iron chelators, such as deferoxamine, have prevented vasospasm in vivo with limited success. However, only chelators of iron in the ferric state have been studied in animal models of vasospasm after SAH. Because free radical formation requires the ferrous (Fe++) moiety and Fe++is a potent binder of the vasodilator nitric oxide, the authors hypothesized that iron in the ferrous state causes vasospasm and that chelators of Fe++, such as 2,2′-dipyridyl, may prevent vasospasm. This study was undertaken to investigate the influence of 2,2′-dipyridyl on vasospasm after induction of SAH in a primate model.

Methods.Twelve cynomolgus monkeys were randomly divided into two groups and then both groups underwent placement of an arterial autologous blood clot in the subarachnoid space around the right middle cerebral artery (MCA). The five animals in the control group received intravenously administered saline and the seven treated animals received intravenously administered chelator (2,2′-dipyridyl) for 14 days. Sequential arteriography for assessment of MCA diameter was performed before and on the 7th day after SAH.

Conclusions.Prevention of cerebral vasospasm by means of treatment with continuous intravenous administration of 2,2′-dipyridyl is reported in a primate model of SAH. This result provides insight into the possible mechanism of delayed vasospasm after aneurysmal SAH and provides a potential preventive therapy for it.
Efficacy and biocompatibility of a photopolymerized, synthetic, absorbable hydrogel as a dural sealant in a canine craniotomy model
Authors: Alleyne Cargill H. , Cawley C. Michael , Barrow Daniel L. , Poff Bradley C. , Powell Michelle D. , Sawhney Amarpreet S. , Dillehay Dirck L.
Published: June 2009

Object. A canine craniotomy model was used to evaluate the dural sealing efficacy and biocompatibility of a novel, synthetic, bioresorbable hydrogel.

Methods. Bilateral craniotomies were performed in 24 dogs assigned to six survival periods. In each animal a parasagittal durotomy was created and then repaired. At the treatment sites the hydrogel sealant was applied over the dural repair and photopolymerized. The repair was tested for leaks to 20 cm H2O by using a Valsalva maneuver. At the control sites the incisions were sutured and tested for leaks only. After uneventful survival periods, the leak test was repeated in three of the four animals in each group. Bone—dura adhesion was evaluated, after which the dura and underlying brain were removed, fixed, and examined histologically. En bloc histological investigation was performed on a specimen obtained from the fourth animal in each group.

Over a 56-day period, 18 treated sites were tested for leaks. A leak was detected at a site remote from that of the repair in one animal; this was excluded from analysis. Thus 17 of 17 treated sites remained free of leaks. On the control side of one animal, there was a leak from a new dural tear at the cranial end of the durotomy, which occurred when the bone flap was removed. This site was also excluded from analysis. Eleven of 17 leak-tested control sites remained free of leaks over the study period. Bone—dura adhesions occurred in 15 of 19 control sites and had a mean adhesion score of 1.37 (range 0–4), whereas adhesions occurred in 10 of 19 treated sites with a mean adhesion score of 0.84 (range 0–3). No cortical reaction was noted.

Conclusions. This novel hydrogel sealant is efficacious in sealing dural repair sites measuring up to 2 mm. Healing of the underlying dura is not compromised and exposed cortical tissue is not altered histologically.
Malignant transformation of ganglioneuroma into spinal neuroblastoma in an adult
Authors: Kulkarni Abhaya V. , Bilbao Juan M. , Cusimano Michael D. , Muller Paul J.
Published: June 2009

✓ Ganglioneuroma is generally considered to be a benign tumor and potentially surgically curable. The authors present a case of a 21-year-old woman who underwent resection of a retroperitoneal ganglioneuroma and developed spinal neuroblastoma 11 years later. She has survived 10 more years with only recent development of metastases. To the authors' knowledge, this is the first report of malignant transformation of a ganglioneuroma into a neuroblastoma. Also, such long-term survival in an adult with spinal neuroblastoma has not been reported previously. This case raises the possibility of a dedifferentiating potential for ganglion cells in a ganglioneuroma or the presence of a long-term, quiescent form of neuroblastoma.
Sequential outer-table craniotomy in a hyperossified meningioma
Authors: Colón Gary P. , Ross Donald A. , Hoff Julian T.
Published: June 2009

✓ A hyperossified meningioma with significant calvarial thickening is fairly common. Craniectomy of the involved region followed by cranioplasty is usually required to resect the bone overgrowth. However, in some cases, the hyperossified calvaria is too thick to allow safe penetration with a craniotome or trephine. In this report, the authors present a technique for preserving the outer calvaria while still resecting the majority of the underlying tumor mass. The key is to perform a craniotomy in a region adjacent to the hyperossified bone and to remove the tumorous, ossified inner table through this “window” by means of a high-speed drill. A second craniotomy can then be performed over the undermined area; this maneuver can be advanced and repeated until the tumor is resected. Frameless stereotactic guidance and microplates are useful in performing this procedure.
Ruptured giant intracranial aneurysms. Part II. A retrospective analysis of timing and outcome of surgical treatment
Authors: Piepgras David G. , Khurana Vini G. , Whisnant Jack P.
Published: June 2009

Object. This retrospective study was made to determine the relationship between surgical timing and outcome in all patients with ruptured giant intracranial aneurysms undergoing surgical treatment at the Mayo Clinic between 1973 and 1996.

Methods. The authors studied 109 patients, 102 of whom were referred from other medical centers. The ruptured giant aneurysms were 25 to 60 mm in diameter. One hundred five of the patients survived the rupturing of the aneurysm to undergo operation, with direct surgery possible in 84% of cases. Excluding delayed referrals, the average time to surgery after admission to the Mayo Clinic was approximately 4 to 5 days. Patients admitted earlier tended to be in poorer condition, often undergoing earlier operation. On average, surgical treatment was administered later for patients with ruptured aneurysms of the posterior circulation than for those with aneurysms in the anterior circulation. Temporary occlusion of the parent vessel was necessary in 67% of direct procedures, with an average occlusion time of 15 minutes. Among surgically treated patients, a favorable outcome was achieved in 72% harboring ruptured anterior circulation aneurysms and in 78% with ruptured posterior circulation lesions.

Conclusions. The overall management mortality rate was 21.1%, and the mortality rate for surgical management was 8.6%. The authors believe that because of the technical difficulties and risk of rebleeding associated with ruptured giant intracranial aneurysms, timely referral to and well-planned treatment at medical centers specializing in management of these lesions are essential to effect a more favorable outcome.
Prevalence of cerebral aneurysms in patients with fibromuscular dysplasia: a reassessment
Authors: Cloft Harry J. , Kallmes David F. , Kallmes Michelle H. , Goldstein Jonas H. , Jensen Mary E. , Dion Jacques E.
Published: June 2009

Object. The aim of this study was to determine the prevalence of cerebral saccular aneurysms in patients with carotid artery and/or vertebral artery (VA) fibromuscular dysplasia (FMD).

Methods. A metaanalysis was performed using data from 17 previously reported series of patients with internal carotid artery (ICA) and/or VA FMD that included information on the prevalence of cerebral aneurysms. In addition, the authors retrospectively evaluated their own series of 117 patients with ICA and/or VA FMD to determine the prevalence of cerebral aneurysms. The metaanalysis of the 17 earlier series, which included 498 patients, showed a 7.6 ± 2.5% prevalence of incidental, asymptomatic aneurysms in patients with ICA and/or VA FMD. In the authors' series of patients with FMD, 6.3 ± 4.9% of patients harbored an incidental, asymptomatic aneurysm. When the authors' series was combined with those included in the metaanalysis, the prevalence was found to be 7.3 ± 2.2%. The prevalence of aneurysms in the general population would have to be greater than 5.6% for there to be no statistically significant difference (chi-square test, p < 0.05) when compared with this 7.3% prevalence in patients with FMD.

Conclusions. The prevalence of intracranial aneurysms in patients with cervical ICA and/or VA FMD is approximately 7%, which is not nearly as high as the 21 to 51% prevalence that has been previously reported.
Direct packing of the isolated sinus in patients with dural arteriovenous fistulas of the transverse—sigmoid sinus
Authors: Endo Shunro , Kuwayama Naoya , Takaku Akira , Nishijima Michiharu
Published: June 2009

Object. The goal of this study was to evaluate the efficacy of direct packing of the isolated sinus (occluded both distally and proximally) in patients with dural arteriovenous fistulas (AVFs) of the transverse—sigmoid sinus.

Methods. Eight patients were included in this study. There were seven men and one woman, ranging in age from 47 to 75 years (mean 60.4 years). Five patients presented with intracranial hemorrhage or venous infarction, one with convulsions, and two with pulsatile tinnitus. Prominent retrograde cortical venous drainage due to sinus isolation was angiographically demonstrated in all patients. All patients were treated by a small craniotomy and direct sinus packing with microcoils; the procedure was performed with the aid of digital subtraction angiography. Five patients were pretreated with transarterial embolization to reduce arterial inflow before the procedure, and intrasinus pressure and sinus blood gases were monitored throughout the operation. Postsurgery, the dural AVF was completely obliterated in all patients. The sinus pressure was 29 to 58% of systemic blood pressure, and sinus blood gas levels were purely arterial before packing. There was no morbidity related to direct sinus packing; however, one patient died as a result of acute myocardial infarction. Over a follow-up period ranging from 1 to 5 years, a faint asymptomatic dural AVF recurred in one patient on the cortex adjacent to the occluded sinus but regressed spontaneously within 1 year.

Conclusions. Direct sinus packing was found to be highly effective for the treatment of dural AVFs that empty into the isolated sinus. Measurement of changes in sinus pressure and sinus blood gas levels was useful for monitoring the progress of direct sinus packing.
External hydrocephalus after aneurysm surgery: paradoxical response to ventricular shunting
Authors: Yoshimoto Yuhei , Wakai Susumu , Hamano Masaaki
Published: June 2009

Object. The authors sought to investigate the mechanisms and pathophysiological effects of subdural fluid collection after surgery for aneurysmal subarachnoid hemorrhage (SAH).

Methods. The authors retrospectively analyzed the medical records of 76 patients who had undergone craniotomy. The patients included 55 with aneurysmal SAH (SAH group) and 21 with unruptured aneurysms (non-SAH group) who were used as controls. Subdural fluid collection was more common in the SAH than in the non-SAH group (38% compared with 14%, p < 0.05). Although older patients appeared to be at greater risk for subdural fluid collection in both groups (p < 0.05), this condition developed even in relatively young patients with SAH. In the SAH group most subdural fluid collection was associated with ventricular dilation (81%), and a significant correlation was seen between fluid collection and the need for subsequent shunt placement (48% compared with 21%, p < 0.05). These results point to an association between hydrodynamic dysfunction and subdural fluid collection. The course of patients with subdural fluid collection varied from spontaneous resolution to normal-pressure hydrocephalus. Seven patients with persistent subdural collections underwent shunt placement (ventriculoperitoneal [VP] shunt in six and lumboperitoneal in one), which resulted in resolution of fluid collection in all seven.

Conclusions. The results indicate that for most patients in the SAH group, subdural fluid collection represented “external hydrocephalus” rather than simple “subdural hygroma.” Decreased absorption of cerebrospinal fluid because of SAH and surgically created tears in the arachnoid membrane communicating with the subdural space were factors in the development of external hydrocephalus. The authors believe that differentiating external hydrocephalus from subdural hygroma is extremely important, because VP shunt placement can be used to treat the former but could worsen the latter.
Neurotopographic considerations in the microsurgical treatment of small acoustic neurinomas
Authors: Koos Wolfgang T. , Day J. Diaz , Matula Christian , Levy David I.
Published: June 2009

Object. The authors studied the relationships between tumor size, location, and topographic position relative to the intact facial nerve bundles in acoustic neurinomas to determine the influence of these factors on hearing preservation postoperatively. Consistent topographic relationships were found.

Methods. Four hundred fifty-two patients with acoustic neurinoma treated via a retrosigmoid approach were analyzed with respect to hearing preservation and facial nerve function. One hundred fifteen tumors were identified as small and were categorized as Grades I and II. Patients with Grade I tumors, that is, purely intracanalicular lesions, all had good hearing preoperatively, defined by a less than 50-dB pure tone average and 50% speech discrimination score. All 14 Grade I tumors were removed, resulting in preservation of the patient's hearing by these criteria. There were no particular topographic anatomical relationships associated with these tumors that affected hearing preservation. Grade II tumors, defined as those protruding into the cerebellopontine angle without contacting the brainstem, were found in 101 patients and were divided by size into two grades: IIA (< 1 cm) and IIB (1–1.8 cm). In 90 patients with Grade IIA tumors, 72 (89%) of 81 who had preserved hearing preoperatively maintained it postoperatively, and in the 11 patients with Grade IIB tumors, six of whom had good hearing preoperatively, four (67%) had preserved hearing postoperatively. Six morphological types were identified based on their neurotopographic relationships to the elements of the vestibulocochlear nerve.

Conclusions. Hearing preservation postsurgery by tumor type was as follows: 1A, 92%; 1B, 88%; 1C, 100%; 2A, 83%; 2B, 92%; and 3, 57%. Combined, this represents a hearing preservation rate of 87% after surgical treatment of Grade II acoustic neurinomas. Full nerve function was maintained in 88% of patients with anatomically preserved facial nerves in both Grade I and II tumors. The remaining 12% of patients retained partial function of the facial nerve. Two patients in the series lost anatomical integrity of the nerve due to surgery.
Resistance to growth inhibition by transforming growth factor—β in malignant glioma cells with functional receptors
Authors: Isoe Shiro , Naganuma Hirofumi , Nakano Shin , Sasaki Atsushi , Satoh Eiji , Nagasaka Mitsuyasu , Maeda Shuichiro , Nukui Hideaki
Published: June 2009

Object.The aim of this study was to investigate the mechanism by which malignant glioma cells escape from growth inhibition mediated by transforming growth factor-β (TGF-β), a ubiquitous cytokine that inhibits cell proliferation by causing growth arrest in the G1phase of the cell cycle.

Methods.The authors measured the response of eight malignant glioma cell lines to the growth-inhibiting activity of TGF-β in vitro and the expression of TGF-β Types I and II receptors in malignant glioma cells. The effect of TGF-β on the expression of a p27Kip1cyclin-dependent kinase inhibitor was also investigated to assess the downstream signal transmission from TGF-β receptors. All malignant glioma cell lines were insensitive to growth inhibition by TGF-β1 and TGF-β2. Analyses of TGF-β receptors by means of affinity labeling in which125I-TGF-β1 was used showed that six glioma lines had both TGF-β Types I and II receptors on their cell surfaces, whereas two lines had very small amounts of TGF-β Type I and/or Type II receptors. Northern blot analysis showed that all tumor lines expressed variable levels of messenger RNAs for both TGF-β Types I and II receptors. Flow cytometric analyses revealed that treatment of malignant glioma cells with TGF-β1 significantly downregulated the expression of p27Kip1protein in all malignant glioma cell lines except one.

Conclusions.The authors suggest that most malignant glioma cells express TGF-β Types I and II receptors, which can transmit some signals downstream and that the loss of response to TGF-β growth inhibition may not be caused by an abnormality of the TGF-β receptors.
Formation of autocrine loops in human cerebral meningioma tissue by leukemia inhibitor factor, interleukin-6, and oncostatin M: inhibition of meningioma cell growth in vitro by recombinant oncostatin M
Authors: Schrell Uwe M. H. , Koch Hans Uwe , Marschalek Rolf , Schrauzer Thomas , Anders Marc , Adams Eric , Fahlbusch Rudolf
Published: June 2009

Object.It has been demonstrated that growth of cerebral meningiomas found in humans is controlled by a variety of factors, including growth factors, aminergic agents, neuropeptides, and steroids. To further our knowledge of this process, the authors investigated the presence and function of the cytokines leukemia inhibitory factor (LIF), interleukin-6 (IL-6), and oncostatin M (OSM) on meningioma cell proliferation.

Methods.Active transcription of LIF, IL-6, and OSM, their related receptors (LIF-R, IL-6-R, and gp130), and the consecutive signal-transducing molecules (STAT 1, STAT 3, and STAT 5a) were analyzed in reverse transcriptase—polymerase chain reaction experiments.

The presence of endogenous LIF, IL-6, and OSM proteins was demonstrated in the supernatant of cultured meningioma cells using the enzyme-linked immunosorbent assay and Western blot experiments, thus indicating an autocrine signaling pathway for all three cytokines.

The biological function of all three cytokines was evaluated by studying their effects on meningioma cell growth. Recombinant LIF and IL-6 showed no significant growth modulating effects; however, recombinant OSM decreased meningioma cell growth by 66%. The antiproliferative potency of OSM was demonstrated by cell count experiments, the [3H]thymidine incorporation assay, and cell cycle analysis.

Conclusions.These in vitro data support the concept that growth of meningioma cells may be modulated by cytokines, and they also indicate that recombinant OSM may be one future candidate for use in the adjuvant treatment of inoperable and recurrent meningiomas.
Epidural hematoma of the clivus
Authors: Mizushima Hidekatsu , Kobayashi Nobusuke , Sawabe Yoshiharu , Hanakawa Kazuo , Jinbo Hiroyuki , Iida Masataka , Iwata Takanobu , Matsumoto Kiyoshi
Published: June 2009

✓ This 8-year-old boy presented with a rare case of epidural hematoma of the clivus and atlantoaxial dislocation caused by a hyperflexion injury sustained in a traffic accident. Magnetic resonance (MR) imaging demonstrated an epidural hematoma in the posterior fossa that compressed the pons and medulla. On admission, the patient was confused and had bilateral abducens palsy. He was treated conservatively, and 6 months after admission, the epidural hematoma on the clivus had disappeared on MR imaging and the bilateral abducens palsy was cured. Only two such cases have been reported in the literature. In this report, the authors discuss the mechanism of hematoma formation in this region of the brain.
Depressed skull fracture overlying the superior sagittal sinus as a cause of benign intracranial hypertension
Authors: Uzan Mustafa , Çiplak Nejat , Dashti S. G. Reza , Bozkus Hakan , Erdinçler Pamir , Akman Canan
Published: June 2009

✓ The use of surgical treatment for depressed skull fractures that are located over major venous sinuses is a matter of controversy. However, if clinical and radiological findings of sinus obliteration and related intracranial hypertension are present, surgical decompression is indicated. The authors present the case of a 38-year-old man who had a depressed skull fracture overlying the posterior one-third portion of the superior sagittal sinus. The lesion was initially treated conservatively and the patient was readmitted 1 month later with signs and symptoms of intracranial hypertension. The role of radiological investigation in the detection of venous sinus flow and indications for surgical treatment are discussed. If venous sinus flow obstruction is revealed in the presence of signs and symptoms of intracranial hypertension, surgery is indicated as the first line of treatment.
Experience in the surgical management of 82 symptomatic herniated thoracic discs and review of the literature
Authors: Stillerman Charles B. , Chen Thomas C. , Couldwell William T. , Zhang Wei , Weiss Martin H.
Published: June 2009

Object.The authors aimed to develop management strategies for the treatment of herniated thoracic discs and to define indications for selection of surgical approaches. Symptomatic thoracic discs requiring surgery are rare. Between 1971 and 1995, 71 patients with 82 herniated thoracic discs were surgically treated by the authors. The treated group included 34 men and 37 women whose ages ranged from 19 to 75 years, with a mean age of 48 years. The most common sites of disc herniation requiring surgery were from T-8 to T-11. Evidence of antecedent trauma was present in 37% of the patients. Preoperative symptoms included pain (localized, axial, or radicular) in 54 (76%) of the 71 patients, evidence of myelopathy, that is, motor impairment in 43 (61%), hyperreflexia and spasticity in 41 (58%), sensory impairment in 43 (61%), and bladder dysfunction in 17 (24%).

Methods.Radiological diagnosis for the patients in this series was accomplished by means of myelography, computerized tomography myelography, or magnetic resonance imaging. Classification of the disc location into two groups reveals that 94% were centrolateral and 6% were lateral. Evidence of calcification was present in 65% of patients, and in 7% intradural extension was noted at surgery. Ten patients (14%) were found to have multiple herniations. Four surgical approaches were used for the removal of these 82 disc herniations: transthoracic in 49 (60%), transfacet pedicle-sparing in 23 (28%), lateral extracavitary in eight (10%), and transpedicular in two (2%). Postoperative evaluation revealed improvement or resolution of pain in 47 (87%) of 54, hyperreflexia and spasticity in 39 (95%) of 41, sensory changes in 36 (84%) of 43, bowel/bladder dysfunction in 13 (76%) of 17, and motor impairment in 25 (58%) of 43. Complications occurred in a total of 12 (14.6%) of 82 discs treated surgically. Major complications were seen in three patients and included perioperative death from cardiopulmonary compromise, instability requiring further surgery, and an increase in the severity of a preoperative paraparesis.

Conclusions.Review of this series, with the attendant complications, together with evaluation of several contemporary thoracic disc series, has facilitated the authors' decision-making process when considering the comprehensive management of these patients, including the selection of a surgical approach.
Vertebral artery injury in C1–2 transarticular screw fixation: results of a survey of the AANS/CNS Section on Disorders of the Spine and Peripheral Nerves
Authors: Wright Neill M. , Lauryssen Carl
Published: June 2009

Object. The 847 active members of the American Association of Neurological Surgeons/Congress of Neurological Surgeons (AANS/CNS) Section on Disorders of the Spine and Peripheral Nerves were surveyed to quantitate the risk of vertebral artery (VA) injury during C1–2 transarticular screw placement.

Methods. This retrospective study elicited the number of patients treated with transarticular screws, the number of screws placed, the incidence of VA injury and subsequent neurological deficit, and the management of known or suspected VA injury.

Two hundred thirteen (25.1%) of the 847 surgeons responded. One hundred one respondents (47.4%) had placed a total of 2492 C1–2 transarticular screws in 1318 patients. Thirty-one patients (2.4%) had known VA injuries and an additional 23 patients (1.7%) were suspected of having injuries. However, only two (3.7%) of the 54 patients with known or suspected VA injuries exhibited subsequent neurological deficits and only one (1.9%) died of bilateral VA injury. Other iatrogenic complications included dural tears, screw fractures, screw breakout, fusion failure, infection, and suboccipital numbness.

Conclusions. Including both known and suspected cases, the risk of VA injury was 4.1% per patient or 2.2% per screw inserted. The risk of neurological deficit from VA injury was 0.2% per patient or 0.1% per screw, and the mortality rate was 0.1%. The choice of management of intraoperative VA injuries was evenly divided between placing the patient under observation and initiating immediate postoperative angiography with possible balloon occlusion.
Magnetic resonance imaging—documented extravasation as an indicator of acute hypertensive intracerebral hemorrhage
Authors: Murai Yasuo , Ikeda Yukio , Teramoto Akira , Tsuji Yukihide
Published: June 2009

Object. The aim of this study was to determine the usefulness of magnetic resonance (MR) imaging—documented extravasation as an indicator of continued hemorrhage in patients with acute hypertensive intracerebral hemorrhage (ICH).

Methods. The authors studied 108 patients with acute hyperintensive ICH. Imaging modalities included noncontrast-enhanced computerized tomography (CT) scanning, gadolinium-enhanced MR imaging, and conventional cerebral angiography obtained within 6 hours after the onset of hemorrhage. A repeated CT scan was obtained within 48 hours to evaluate enlargement of the hematoma.

Findings on MR imaging indicating extravasation, including any high-intensity signals on T1-weighted postcontrast images, were observed in 39 patients, and 17 of these also showed evidence of extravasation on cerebral angiography. The presence of extravasation on MR imaging was closely correlated with evidence of hematoma enlargement on follow-up CT scans (p < 0.001).

Conclusions. Evidence of extravasation documented on MR imaging indicates persistent hemorrhage and correlates with enlargement of the hematoma.
Magnetic resonance cisternography for visualization of intracisternal fine structures
Authors: Mamata Yoshiaki , Muro Isao , Matsumae Mitsunori , Komiya Taizo , Toyama Hiroyuki , Tsugane Ryuichi , Sato Osamu
Published: June 2009

Object. To assess its usefulness in demonstrating cisternal anatomy, the authors investigated magnetic resonance (MR) cisternography in which a heavily T2-weighted turbo spin—echo method was used to visualize normal anatomical fine structures and lesions in the basal cisterns in 20 healthy volunteers and 43 patients. The authors applied peripheral pulse gating, which had been optimized to reduce artifacts in the cisterns attributable to cerebrospinal fluid (CSF) flow.

Methods. The detectability of each cranial nerve was determined in healthy volunteers. The first, second, and third nerves and the seventh—eighth nerve complex were clearly visualized in all participants; the fifth nerve was clearly seen in 80% and the sixth cranial nerve in 50%. The fourth nerve and the ninth through 12th nerves were difficult to identify individually, except in some volunteers.

To reduce artifacts caused by fast CSF flow, we determined the delays as a function of the time elapsed between two consecutive peaks of pulse wave in a peripheral pulse gate (P—P interval) at which there was reversal of flow direction to minimize the CSF flow—related artifact. Using peripheral pulse gating and a time delay of 30% of the R—R interval, the authors succeeded in minimizing the CSF flow—related artifacts.

Magnetic resonance cisternography appears to be very useful for demonstrating intracisternal fine anatomy and enhancing the contours of the juxtacisternal lesion. A minute amount of CSF interposed between lesions and normal structures such as nerves, vessels, or bone structures can be detected by means of this sequence. In patients with facial spasm, axial images and oblique coronal images obtained in a plane parallel to the seventh—eighth cranial nerve complex demonstrated vascular compression in all 13 patients. The MR cisternography finding of compression was confirmed in all nine patients who underwent microvascular decompression.

Conclusions. Magnetic resonance cisternography appears to show great promise for evaluation of patients with neurovascular compression or tumors in and around the basal cisterns; the procedure adds only a small amount of imaging time.
Generator sites of early scalp potentials evoked from the three trigeminal branches
Authors: Leandri Massimo
Published: June 2009

Object. The aim of this study was to seek evidence about the generators of the first three components of the scalp's early trigeminal evoked potentials (TEPs) obtained by stimulation of the supraorbital (SW1, SW2, and SW3), infraorbital (W1, W2, and W3) and mental (MW1, MW2, and MW3) nerves.

Methods. Simultaneous scalp and depth recordings were measured during surgical procedures in which thermorhizotomy and microvascular decompression were performed.

Conclusions. Direct evidence was found that the origin of MW1 lies in the mandibular nerve at the foramen ovale, whereas the origin of W1 in the maxillary nerve at the foramen rotundum and the origin of SW1 in the ophthalmic nerve at the superior orbital fissure could only be inferred. The generators of SW2, W2, and MW2 were found to be on the nerve root at a distance of 10 mm from the pons. Calculations based on conduction velocity suggested that the generators of SW3, W3, and MW3 were inside the brainstem, at distances between 16 mm and 20 mm from the root entry zone.

Recordings obtained in eight patients with discrete surgical lesions of the trigeminal pathway confirmed the sites of origin of the early components and further proved that only the fastest group of fibers is responsible for scalp responses.