Showing papers in "Journal of Neurosurgery in 2001"
TL;DR: Gross-total tumor resection is associated with longer survival in patients with GBM, especially when other predictive variables are favorable.
Abstract: Object. The extent of tumor resection that should be undertaken in patients with glioblastoma multiforme (GBM) remains controversial. The purpose of this study was to identify significant independent predictors of survival in these patients and to determine whether the extent of resection was associated with increased survival time. Methods. The authors retrospectively analyzed 416 consecutive patients with histologically proven GBM who underwent tumor resection at the authors' institution between June 1993 and June 1999. Volumetric data and other tumor characteristics identified on magnetic resonance (MR) imaging were collected prospectively. Conclusions. Five independent predictors of survival were identified: age, Karnofsky Performance Scale (KPS) score, extent of resection, and the degree of necrosis and enhancement on preoperative MR imaging studies. A significant survival advantage was associated with resection of 98% or more of the tumor volume (median survival 13 months, 95% confidence interval [C...
2,641 citations
TL;DR: A critical review of literature pertinent to low-grade gliomas of the cerebral hemisphere in adults was performed to evaluate systematically the prognostic effect of extent of resection on survival and to determine if treatment-related guidelines could be established for patients in whom these tumors have been newly diagnosed.
Abstract: Object. The goal of this study was to perform a critical review of literature pertinent to low-grade gliomas of the cerebral hemisphere in adults and, on the basis of this review, to evaluate systematically the prognostic effect of extent of resection on survival and to determine if treatment-related guidelines could be established for patients in whom these tumors have been newly diagnosed. Quality of evidence for current treatment options, guidelines, and standards as well as methodological limitations were evaluated. Methods. Several prognostic factors thought to affect outcome in patients with low-grade gliomas include the patient's age and neurological status, tumor volume and histological characteristics, and treatment-related variables such as timing of surgical intervention, extent of resection, postoperative tumor volume, and radiation therapy. Patient age and the histological characteristics of the lesion are generally accepted prognostic factors. Among treatment-related factors, timing and exte...
458 citations
TL;DR: Radiosurgery for acoustic neuroma performed using current procedures is associated with a continued high rate of tumor control and lower rates of posttreatment morbidity than those published in earlier reports.
Abstract: Object. The goal of this study was to define tumor control and complications of radiosurgery encountered using current treatment methods for the initial management of patients with unilateral acoustic neuroma. Methods. One hundred ninety patients with previously untreated unilateral acoustic neuromas (vestibular schwannomas) underwent gamma knife radiosurgery between 1992 and 1997. The median follow-up period in these patients was 30 months (maximum 85 months). The marginal radiation doses were 11 to 18 Gy (median 13 Gy), the maximum doses were 22 to 36 Gy (median 26 Gy), and the treatment volumes were 0.1 to 33 cm3 (median 2.7 cm3). The actuarial 5-year clinical tumor-control rate (no requirement for surgical intervention) for the entire series was 97.1 ± 1.9%. Five-year actuarial rates for any new facial weakness, facial numbness, hearing-level preservation, and preservation of testable speech discrimination were 1.1 ± 0.8%, 2.6 ± 1.2%, 71 ± 4.7%, and 91 ± 2.6%, respectively. Facial weakness did not dev...
385 citations
TL;DR: In this article, the post-operative recurrence rate of chronic subdural hematomas (CSDHs) has been investigated based on the natural history of these lesions and their intracranial extension.
Abstract: Object. Factors affecting the postoperative recurrence of chronic subdural hematomas (CSDHs) have not been sufficiently investigated. The authors have attempted to determine features of CSDHs that are associated with a high or low recurrence rate on the basis of the natural history of these lesions and their intracranial extension. Methods. One hundred six patients (82 men and 24 women) harboring 126 CSDHs who were treated at Tokyo Kosei Nenkin Hospital between January 1989 and April 1998 were studied. Types of CSDHs were classified according to hematoma density and internal architecture, and the intracranial extension of the hematomas were investigated. The postoperative recurrence rate was calculated for each factor. Based on the internal architecture and density of each hematoma, the CSDHs were classified into four types, including homogeneous, laminar, separated, and trabecular types. The recurrence rate associated with the separated type was high, whereas that associated with the trabecular type was ...
322 citations
TL;DR: Three variables associated with an increased incidence of shunt infection have been identified and great care should be taken intraoperatively to avoid a postoperative CSF leak.
Abstract: Object. Hydrocephalus is a common condition of childhood that usually requires insertion of a cerebrospinal fluid (CSF) shunt. Infection is one of the most devastating complications that may arise from the presence of CSF shunts. In this study, the authors prospectively analyzed perioperative risk factors for CSF shunt infection in a cohort of children. Methods. Between 1996 and 1999, 299 eligible patients underwent CSF shunt operations (insertions and revisions) that were observed by a research nurse at a tertiary care pediatric hospital. Several perioperative variables were recorded. All cases were followed postoperatively for 6 months to note any development of CSF shunt infection. A Cox proportional hazards model was used to analyze the relationship between the variables and the development of shunt infection. Thirty-one patients (10.4%) experienced shunt infection. Three perioperative variables were significantly associated with an increased risk of shunt infection: 1) the presence of a postoperative CSF leak (hazard ratio [HR] 19.16, 95% confidence interval [CI] 6.96‐52.91); 2) patient prematurity (� 40 weeks’ gestation at the time of shunt surgery: HR 4.72, 95% CI 1.71‐13.06); and 3) the number of times the shunt system was inadvertently exposed to breached surgical gloves (HR 1.07, 95% CI 1.02‐1.12). Conclusions. Three variables associated with an increased incidence of shunt infection have been identified. Changes in clinical practice should address these variables, as follows. 1) Great care should be taken intraoperatively to avoid a postoperative CSF leak. 2) Alternatives to placement of a CSF shunt in premature infants should be studied. 3) Surgeons should minimize manual contact with the shunt system and consider the use of double gloves.
320 citations
TL;DR: With the development of antibiotic drugs and modern microinstrumentation, the transsphenoidal approach became the preferred route for the removal of lesions that were confined to the sella turcica.
Abstract: Initial attempts at transcranial approaches to the pituitary gland in the late 1800s and early 1900s resulted in a mortality rate that was generally considered prohibitive. Schloffer suggested the use of a transsphenoidal route as a safer, alternative approach to the sella turcica. He reported the first successful removal of a pituitary tumor via the transsphenoidal approach in 1906. His procedure underwent a number of modifications by interested surgeons, the culmination of which was A. E. Halstead's description in 1910 of a sublabial gingival incision for the initial stage of exposure. From 1910 to 1925, Cushing, combining a number of suggestions made by previous authors, refined the transsphenoidal approach and used it to operate on 231 pituitary tumors, with a mortality rate of 5.6%. As he developed increasing expertise with transcranial surgery, however, Cushing reduced his mortality rate to 4.5%. With the transcranial approach, he was able to verify suprasellar tumors and achieve better decompression of the optic apparatus, resulting in better recovery of vision and a lower recurrence rate. As a result he and most other neurosurgeons at the time abandoned the transnasal in favor of the transcranial approaches. Norman Dott, a visiting scholar who studied with Cushing in 1923, returned to Edinburgh, Scotland, and continued to use the transsphenoidal procedure while others pursued transcranial approaches. Dott introduced the procedure to Gerard Guiot, who published excellent results with the transsphenoidal approach and revived the interest of many physicians throughout Europe in the early 1960s. Jules Hardy, who used intraoperative fluoroscopy while learning the transsphenoidal approach from Guiot, then introduced the operating microscope to further refine the procedure; he thereby significantly improved its efficacy and decreased surgical morbidity. With the development of antibiotic drugs and modern microinstrumentation, the transsphenoidal approach became the preferred route for the removal of lesions that were confined to the sella turcica. The evolution of the transsphenoidal approaches and their current applications and modifications are discussed.
314 citations
TL;DR: The data strongly indicated that induced hypertension in this high-risk group of patients is associated with the development of symptomatic ARDS, and the association of management strategy and the occurrence of ARDS is strong.
Abstract: Object. The factors involved in the development of adult respiratory distress syndrome (ARDS) after severe head injury were studied. The presence of ARDS complicates the treatment of patients with severe head injury, both because hypoxia causes additional injury to the brain and because therapies that are used to protect the lungs and improve oxygenation in patients with ARDS can reduce cerebral blood flow (CBF) and increase intracranial pressure (ICP). In a recent randomized trial of two head-injury management strategies (ICP-targeted and CBF-targeted), a fivefold increase in the incidence of ARDS was observed in the CBF-targeted group. Methods. Injury severity, physiological data, and treatment data in 18 patients in whom ARDS had developed were compared with the remaining 171 patients in the randomized trial in whom it had not developed. Logistic regression analysis was used to study the interaction of the factors that were related to the development of ARDS. In the final exact logistic regression model, several factors were found to be significantly associated with an increased risk of ARDS: administration of epinephrine (5.7-fold increased risk), administration of dopamine in a larger than median dose (10.8-fold increased risk), and a history of drug abuse (3.1-fold increased risk). Conclusions. Although this clinical trial was not designed to study the association of management strategy and the occurrence of ARDS, the data strongly indicated that induced hypertension in this high-risk group of patients is associated with the development of symptomatic ARDS.
308 citations
TL;DR: The authors suggest that the brain has an increased vulnerability to a second traumatic insult for at least 24 hours following an initial episode of mild brain trauma.
Abstract: Object. Mild, traumatic repetitive head injury (RHI) leads to neurobehavioral impairment and is associated with the early onset of neurodegenerative disease. The authors developed an animal model to investigate the behavioral and pathological changes associated with RHI. Methods. Adult male C57BL/6 mice were subjected to a single injury (43 mice), repetitive injury (two injuries 24 hours apart; 49 mice), or no impact (36 mice). Cognitive function was assessed using the Morris water maze test, and neurological motor function was evaluated using a battery of neuroscore, rotarod, and rotating pole tests. The animals were also evaluated for cardiovascular changes, blood‐brain barrier (BBB) breakdown, traumatic axonal injury, and neurodegenerative and histopathological changes between 1 day and 56 days after brain trauma. No cognitive dysfunction was detected in any group. The single-impact group showed mild impairment according to the neuroscore test at only 3 days postinjury, whereas RHI caused pronounced deficits at 3 days and 7 days following the second injury. Moreover, RHI led to functional impairment during the rotarod and rotating pole tests that was not observed in any animal after a single impact. Small areas of cortical BBB breakdown and axonal injury, observed after a single brain injury, were profoundly exacerbated after RHI. Immunohistochemical staining for microtubule-associated protein‐2 revealed marked regional loss of immunoreactivity only in animals subjected to RHI. No deposits of � -amyloid or tau were observed in any brain-injured animal. Conclusions. On the basis of their results, the authors suggest that the brain has an increased vulnerability to a second traumatic insult for at least 24 hours following an initial episode of mild brain trauma.
307 citations
TL;DR: Autoregulation not only is impaired when associated with a high ICP or low ABP, but it can also be disturbed by too high a CPP.
Abstract: Object. The goal of this study was to examine the relationship between cerebral autoregulation, intracranial pressure (ICP), arterial blood pressure (ABP), and cerebral perfusion pressure (CPP) after head injury by using transcranial Doppler (TCD) ultrasonography. Methods. Using ICP monitoring and TCD ultrasonography, the authors previously investigated whether the response of flow velocity (FV) in the middle cerebral artery to spontaneous variations in ABP or CPP provides reliable information about cerebral autoregulatory reserve. In the present study, this method was validated in 187 head-injured patients who were sedated and receiving mechanical ventilation. Waveforms of ICP, ABP, and FV were recorded over intervals lasting 20 to 120 minutes. Time-averaged mean FV and CPP were determined. The correlation coefficient index between FV and CPP (the mean index of autoregulation [Mx]) was calculated over 4-minute epochs and averaged for each investigation. The distribution of averaged mean FV values converg...
304 citations
TL;DR: Radiosurgery for idiopathic trigeminal neuralgia was safe and effective, and it provided benefit to a patient population with a high frequency of prior surgical intervention.
Abstract: Object. Stereotactic radiosurgery is an increasingly used and the least invasive surgical option for patients with trigeminal neuralgia. In this study, the authors investigate the clinical outcomes in patients treated with this procedure. Methods. Independently acquired data from 220 patients with idiopathic trigeminal neuralgia who underwent gamma knife radiosurgery were reviewed. The median age was 70 years (range 26–92 years). Most patients had typical features of trigeminal neuralgia, although 16 (7.3%) described additional atypical features. One hundred thirty-five patients (61.4%) had previously undergone surgery and 80 (36.4%) had some degree of sensory disturbance related to the earlier surgery. Patients were followed for a maximum of 6.5 years (median 2 years). Complete or partial relief was achieved in 85.6% of patients at 1 year. Complete pain relief was achieved in 64.9% of patients at 6 months, 70.3% at 1 year, and 75.4% at 33 months. Patients with an atypical pain component had a lower rate ...
292 citations
TL;DR: Induced Hypothermia is associated with severe electrolyte depletion, which is at least partly due to increased urinary excretion through hypothermia-induced polyuria, which may be the mechanism through which induced hypotheria can lead to arrhythmias.
Abstract: Object. Induced hypothermia in patients with severe head injury may prevent additional brain injury and improve outcome. However, this treatment is associated with severe side effects, including life-threatening cardiac tachyarrhythmias. The authors hypothesized that these arrhythmias might be caused by electrolyte disorders and therefore studied the effects of induced hypothermia on urine production and electrolyte levels in patients with severe head injury. Methods. Urine production, urine electrolyte excretion, and plasma levels of Mg, phosphate, K, Ca, and Na were measured in 41 patients with severe head injury. Twenty-one patients (Group 1, study group) were treated using induced hypothermia and pentobarbital administration, and 20 patients (Group 2, controls) were treated with pentobarbital administration alone. In Group 1, Mg levels decreased from 0.98 ± 0.15 to 0.58 ± 0.13 mmol/L (mean ± standard deviation; p < 0.01), phosphate levels from 1.09 ± 0.19 to 0.51 ± 0.18 mmol/L (p < 0.01), Ca levels fr...
TL;DR: Mild hypothermia should not be used for the treatment of severely head injured patients with low ICP because this therapy conveys no advantage over normothermia in such patients.
Abstract: Object. The criteria for the use of mild hypothermia (34°C) in severely head injured patients have not been standardized. A prospective randomized controlled trial was conducted to determine whether mild hypothermia is essential in the treatment of severely head injured patients with low intracranial pressure (ICP). Methods. At 11 medical centers, 91 severely head injured patients with an admission Glasgow Coma Scale score of 8 or less in whom ICP could be maintained below 25 mm Hg by conventional therapies were divided randomly into two groups: the mild hypothermia group (HT group, 45 patients) and the normothermia group (NT group, 46 patients). Patients in the HT group were exposed to mild hypothermia (34°C) for 48 hours, followed by rewarming at 1°C per day for 3 days, whereas patients in the NT group were exposed to normothermia (37°C) for 5 days. The two groups were similar with respect to prognostic factors, and there was no difference in clinical outcome at 3 months postinjury. During treatment, th...
TL;DR: The microendoscopic posterior laminoforaminotomy is an effective alternative for the treatment of unilateral cervical radiculopathy secondary to lateral or foraminal disc herniations or spondylosis and is associated with a much quicker return to unrestricted full activity than that obtained with other techniques.
Abstract: Object. In this report the author presents surgery-related outcomes after application of a new technique. A posterior microendoscopic laminoforaminotomy was used for the surgical treatment of unilateral cervical radiculopathy secondary to intervertebral disc herniations and/or spondylotic foraminal stenosis. The results of this procedure are compared with those achieved using traditional laminoforaminotomy and anterior cervical discectomy with or without fusion. Methods. One hundred consecutive patients who experienced unilateral cervical radicular syndromes, which were refractory to conservative therapy, and in whom imaging studies had confirmed lateral canal or foraminal compression, underwent surgical treatment. An endoscopy-assisted posterior laminoforaminotomy was performed using a microendoscopic visualization system for removal of herniated disc and foraminal decompression while the patient was in the sitting position. Excellent or good results were obtained in 97 patients, who returned to their pr...
TL;DR: The authors found a small but definable risk of delayed hemorrhage, despite unremarkable findings on an immediate postbiopsy head CT scan, which justifies an overnight hospital observation stay for all patients after having undergone stereotactic brain biopsy.
Abstract: Object. Stereotactic brain biopsy has played an integral role in the diagnosis and management of brain lesions. At most centers, imaging studies following biopsy are rarely performed. The authors prospectively determined the acute hemorrhage rate after stereotactic biopsy by performing immediate postbiopsy intraoperative computerized tomography (CT) scanning. They then analyzed factors that may influence the risk of hemorrhage and the diagnostic accuracy rate. Methods. Five hundred consecutive patients undergoing stereotactic brain biopsy underwent immediate postbiopsy intraoperative CT scanning. Before surgery, routine preoperative coagulation studies were performed in all patients. All medical charts, laboratory results, preoperative imaging studies, and postoperative imaging studies were reviewed. In 40 patients (8%) hemorrhage was detected using immediate postbiopsy intraoperative CT scanning. Neurological deficits developed in six patients (1.2%) and one patient (0.2%) died. Symptomatic delayed neuro...
TL;DR: Systemic Na+ channel blockers, in particular riluzole, can confer significant neuroprotection after in vivo SCI and result in behavioral recovery and sparing of both gray and white matter.
Abstract: Object. Persistent activation of voltage-sensitive Na+ channels is associated with cellular toxicity and may contribute to the degeneration of neural tissue following traumatic brain and spinal cord injury (SCI). Pharmacological blockade of these channels can attenuate secondary pathophysiology and reduce functional deficits acutely. Methods. To determine the therapeutic effects of Na+ channel blockers on long-term tissue sparing and functional neurological recovery after traumatic SCI, the authors injected Wistar rats intraperitoneally with riluzole (5 mg/kg), phenytoin (30 mg/kg), CNS5546A, a novel Na+ channel blocker (15 mg/kg), or vehicle (2-HPβCD; 5 mg/kg) 15 minutes after induction of compressive SCI at C7—T1. Functional neurological recovery of coordinated hindlimb function and strength, assessed 1 week postinjury and weekly thereafter for 6 weeks, was significantly enhanced in animals treated with riluzole compared with the other treatment groups. Seven weeks postinjury the preservation of residua...
TL;DR: A study to evaluate the effectiveness of endoscopic third ventriculostomy in the management of hydrocephalus before and after surgical intervention for posterior fossa tumors in children in Paris found no significant differences between groups.
Abstract: Object. The authors undertook a study to evaluate the effectiveness of endoscopic third ventriculostomy in the management of hydrocephalus before and after surgical intervention for posterior fossa tumors in children. Methods. Between October 1, 1993, and December 31, 1997, a total of 206 consecutive children with posterior fossa tumors underwent surgery at Hopital Necker—Enfants Malades in Paris. Excluded were 10 patients in whom shunts had been placed at the referring hospital. The medical records and neuroimaging studies of the remaining 196 patients were reviewed and categorized into three groups: Group A, 67 patients with hydrocephalus present on admission in whom endoscopic third ventriculostomy was performed prior to tumor removal; Group B, 82 patients with hydrocephalus who did not undergo preliminary third ventriculostomy but instead received conventional treatment; and Group C, 47 patients in whom no ventricular dilation was present on admission. There were no significant differences between pat...
TL;DR: A good understanding of the surgical anatomy and an awareness of potential pitfalls can help reduce neurological complications and maximize surgical resection of insular tumors.
Abstract: Object. Surgical resection of tumors located in the insular region is challenging for neurosurgeons, and few have published their surgical results. The authors report their experience with intrinsic tumors of the insula, with an emphasis on an objective determination of the extent of resection and neurological complications and on an analysis of the anatomical characteristics that can lead to suboptimal outcomes. Methods. Twenty-two patients who underwent surgical resection of intrinsic insular tumors were retrospectively identified. Eight tumors (36%) were purely insular, eight (36%) extended into the temporal pole, and six (27%) extended into the frontal operculum. A transsylvian surgical approach, combined with a frontal opercular resection or temporal lobectomy when necessary, was used in all cases. Five of 13 patients with tumors located in the dominant hemisphere underwent craniotomies while awake. The extent of tumor resection was determined using volumetric analyses. In 10 patients, more than 90% ...
TL;DR: Large cysts (> 1.5 cm) and the presence of associated radicular symptoms strongly correlate with excellent outcome and the outcome and efficacy of cyst wall resection in 10 patients with symptomatic Tarlov cysts is assessed.
Abstract: Object. Tarlov or perineurial cysts are lesions of the nerve root most often found in the sacral region. Although there is agreement that asymptomatic Tarlov cysts should be followed, it is still debated whether patients with symptomatic Tarlov cysts should be treated surgically. The authors assessed the outcome and efficacy of cyst wall resection in 10 patients with symptomatic Tarlov cysts. The medical literature is reviewed, theories of origin are evaluated, and suggestions as to their cause and pathogenesis are offered. Methods. Ten consecutive patients harboring symptomatic Tarlov cysts were treated by the senior author between 1989 and 1999. All patients were assessed for neurological deficits and pain by neurological examination and visual analog scale, respectively. Computerized tomography myelography was performed in all patients to diagnose delayed filling of the cysts. A sacral laminectomy with resection of the sacral cyst or cysts was performed in all patients. Resected material from eight of ...
TL;DR: Uptake of MET was present in 98% of the gliomas studied and the intensity of MET uptake represents a prognostic factor for WHO Grade II and III tumors considered separately.
Abstract: Object. Positron emission tomography with l-[methyl-11C]methionine (MET-PET) provides information on the metabolism of gliomas. The aim of this study was to determine the predictive value of MET-PET in the treatment of patients with gliomas. Methods. Since 1992, 85 patients with a World Health Organization (WHO) classification—verified glioma underwent PET studies in which MET was injected before (74 cases) or after treatment (11 cases). Analysis of PET data was conducted by the same investigator using two scales: a qualitative visual grading scale and a quantitative scale (ratio between tumor uptake and normal brain uptake, classified on a seven-level scale). Uptake of MET was present in 98% of gliomas. The investigator judged this uptake to be moderate to very high based on visual inspection (qualitative scale). For all grades of gliomas, a visual grade of 3 was statistically associated with a shorter patient survival period (p < 0.005). The tumor/normal brain uptake ratio was significantly influenced b...
TL;DR: Improved surgical safety can be achieved using intraoperative neurophysiological monitoring procedures andetitive stimulation of the motor cortex proved to be a reliable method for monitoring subcortical motor pathways.
Abstract: Object. The repetitive application of high-frequency anodal monopolar stimulation during surgery in or near the motor cortex allows a qualitative and quantitative evaluation of motor evoked potentials (MEPs). Using this method, motor pathways and motor function can be continuously monitored during surgery. Methods. In this prospective study, 70 patients underwent MEP monitoring during surgery performed in the central region. All procedures were performed after general anesthesia had been induced without the aid of muscle relaxants. The motor pathways were monitored during the entire surgical procedure by repetitive high-frequency anodal monopolar stimulation (frequency 400–500 Hz; train 7–10 pulses; impulse duration 0.2–0.7 msec; and stimulation intensity 16.9 ± 7.76 mA). The MEPs were continuously evaluated to assess their latency, potential duration, and amplitude. Recorded alterations in these parameters were subsequently correlated with surgical maneuvers and with postoperative neurological deteriorat...
Journal Article•
TL;DR: Antibiotic therapy is suggested for patients who have symptoms of sepsis, or for patients in whom specific organisms are identified from cultures obtained during surgery, and the transsphenoidal approach is recommended over open craniotomy for surgical drainage.
Abstract: Object. Pituitary abscess is a rare but serious intrasellar infection. To better determine the salient signs and symptoms that help in making the diagnosis, and to determine the most appropriate treatment, the authors reviewed their experience in a series of 24 patients treated at the University of California at San Francisco. Methods. Nine of the patients were female and 15 were male, and their mean age was 41.2 years (range 12–71 years). Surprisingly, most patients in our series presented with complaints and physical findings consistent with a pituitary mass, but rarely with evidence of a serious infection. Headache, endocrine abnormalities, and visual changes were the most common clinical indicators; fever, peripheral leukocytosis, and meningismus were present in 33% or fewer of the patients. Imaging tests demonstrated a pituitary mass in all patients, but the features evident on computerized tomography and magnetic resonance studies did not distinguish pituitary abscesses from other, more common intra...
TL;DR: Intraoperative MR imaging undoubtedly offers the option of a second look within the same surgical procedure, if incomplete tumor resection is suspected, and the rate of procedures during which complete tumor removal is achieved can be improved.
Abstract: Object. The aim of this study was to evaluate whether intraoperative magnetic resonance (MR) imaging can increase the efficacy of transsphenoidal microsurgery, primarily in non—hormone-secreting intra- and suprasellar pituitary macroadenomas. Methods. Intraoperative imaging was performed using a 0.2-tesla MR imager, which was located in a specially designed operating room. The patient was placed supine on the sliding table of the MR imager, with the head placed near the 5-gauss line. A standard flexible coil was placed around the patient's forehead. Microsurgery was performed using MR-compatible instruments. Image acquisition was started after the sliding table had been moved into the center of the magnet. Coronal and sagittal T1-weighted images each required over 8 minutes to acquire, and T2-weighted images were obtained optionally. To assess the reliability of intraoperative evaluation of tumor resection, the intraoperative findings were compared with those on conventional postoperative 1.5-tesla MR ima...
TL;DR: Major morbidity was related mainly to preoperative status and less to surgical treatment, and resection of brainstem cavernomas is the treatment of choice in the majority of these cases because of the high incidence of morbidity related to one or often several brainstem hemorrhages.
Abstract: Object. A careful retrospective analysis of 36 cases was performed to evaluate the pre- and postoperative rates of morbidity that occur in patients with brainstem cavernous angiomas. Methods. The authors evaluated immediate postoperative and follow-up outcomes with regard to clinical findings, the incidence of preoperative hemorrhage(s), location and size of the lesions, and the timing of the surgical procedure after the last hemorrhagic event. Specifically, the following parameters were analyzed: 1) number of hemorrhages; 2) the precise brainstem location (pontomesencephalic, pons, and medulla oblongata); 3) pre- and postoperative cranial nerve status; 4) pre- and postoperative motor and sensory deficits; 5) size (volume) of the lesions; and 6) pre- and postoperative Karnofsky Performance Scale (KPS) scores. Multiple hemorrhages were observed in 16 patients, particularly in those with pontomesencephalic cavernous angiomas (75%). The mean preoperative KPS score was 70.3 ± 16.3 (± standard deviation). Twen...
TL;DR: In this paper, the authors report on seven patients with procedure-related aneurysm rupture in a group of 239 consecutive patients harboring 264 intracranial Aneurysms that were treated with GDCs (Target Therapeutics Corp., Fremont, CA).
Abstract: ELECTIVE occlusion of intracranial aneurysms with detachable coils is a widely accepted treatment modality with a procedure-related permanent complication rate of 3.7%. 2 The main causes of procedurerelated complications during endovascular treatment of intracranial aneurysms with detachable coils are ischemic events and aneurysm perforation. In this study we report on seven patients with procedure-related aneurysm rupture in a group of 239 consecutive patients harboring 264 intracranial aneurysms that were treated with GDCs (Target Therapeutics Corp., Fremont, CA). We assessed the incidence and outcome of this potentially catastrophic event in our own patients as well as those reported in other selected studies. We tried to identify risk factors with emphasis on aneurysm size, history of SAH caused by the treated aneurysm, and the use of a temporary occlusion balloon in wide-necked aneurysms.
TL;DR: An evaluation of multiple risk factor models showed that maximum radiation dose to the brainstem, treatment era (pre-1994 compared with 1994 or later), and prior surgical resection were all simultaneously informative predictors of cranial neuropathy risk.
Abstract: Object. The aim of this study was to identify factors associated with delayed cranial neuropathy following radiosurgery for vestibular schwannoma (VS or acoustic neuroma) and to determine how such factors may be manipulated to minimize the incidence of radiosurgical complications while maintaining high rates of tumor control. Methods. From July 1988 to June 1998, 149 cases of VS were treated using linear accelerator radiosurgery at the University of Florida. In each of these cases, the patient's tumor and brainstem were contoured in 1-mm slices on the original radiosurgical targeting images. Resulting tumor and brainstem volumes were coupled with the original radiosurgery plans to generate dose—volume histograms. Various tumor dimensions were also measured to estimate the length of cranial nerve that would be irradiated. Patient follow-up data, including evidence of cranial neuropathy and radiographic tumor control, were obtained from a prospectively maintained, computerized database. The authors performe...
TL;DR: The balance between the recurrence rate and troublesome sensory complications achieved in this series is favorable when compared with previously published studies on outcomes of PBC and the two alternative percutaneous methods, radiofrequency thermocoagulation and glycerol rhizolysis.
Abstract: Object. The aim of this study was to investigate outcomes and complication rates associated with percutaneous balloon compression (PBC) of the trigeminal ganglion over a long follow-up period. Methods. This retrospective review was conducted in 496 patients with typical symptoms of unilateral trigeminal neuralgia who underwent 531 PBCs of the trigeminal ganglion between 1980 and 1999. The mean length of follow up was 10.7 years. The treatment used was a modification of that first described by Mullan and Lichtor in 1983. There were nine technical failures. Of the 522 successful procedures, prompt pain relief ensued in all patients except one. Recurrence of pain was found in 95 patients (19.2%) within 5 years and in 158 patients (31.9%) over the entire study period. Symptomatic dysesthesias occurred in 19 patients (3.8%), but corneal anesthesia and anesthesia dolorosa did not. Conclusions. In this review the authors present data on the largest cohort of patients with the longest follow up for this procedure...
TL;DR: Prerandomization variables, critical physiological variables, treatment variables, and accrual methodologies were investigated among various centers and hypothermia was found to be detrimental in patients older than the age of 45 years, beneficial in patients younger than 45 years of age, and without effect in those in whom normothermiawas documented on admission.
Abstract: Object In a recently conducted trial of hypothermia in patients with severe brain injury, differences were found in the effects of hypothermia treatment among various centers. This analysis explores the reasons for such differences. Methods The authors reviewed data obtained in 392 patients treated for severe brain injury. Prerandomization variables, critical physiological variables, treatment variables, and accrual methodologies were investigated among various centers. Hypothermia was found to be detrimental in patients older than the age of 45 years, beneficial in patients younger than 45 years of age in whom hypothermia was present on admission, and without effect in those in whom normothermia was documented on admission. Marginally significant differences (p Conclusions For Phase III clinical trials we recommend: 1) a detailed protocol specifying fluid and MABP, ICP, and CPP management: 2) continuous monitoring of protocol compliance; 3) a run-in period for new centers to test accrual and protocol adherence; and 4) inclusion of only centers in which patients are regularly randomized.
TL;DR: The primary mechanism by which a cerebral dissecting aneurysm is created is by the sudden disruption of the IEL, and the plane of dissection extends through the media.
Abstract: Object. The goal of this study was to investigate the pathological mechanism and precise three-dimensional (3D) structure of cerebral dissecting aneurysms in association with their clinical course. Methods. Nine aneurysm specimens were excised from eight patients. Of the nine aneurysms, seven arose from the vertebral artery, one from the anterior cerebral artery, and one from the superior cerebellar artery. Eight aneurysms were accompanied with subarachnoid hemorrhage (SAH) and one with infarction. Seven aneurysms were obtained at autopsy and two were obtained during surgery (trapping and bypass). All nine aneurysms were sectioned into serial axial slices measuring 5 to 10 µm in thickness. Taking each slice as an element, we reconstructed the 3D structure of the aneurysm. The true lumen communicated with a pseudolumen through the disrupted portion of the internal elastic lamina (IEL) in all nine aneurysms. The ruptured portion was located just above the disrupted IEL. Two aneurysms had an exit back into t...
TL;DR: In this paper, the effects of delaying induction of mild hypothermia (33°C) after transient focal cerebral ischemia and to ascertain whether the neuroprotective effects induced during the ischemic period are sustained over time were determined.
Abstract: Object. The goals of this study were to determine the effects of delaying induction of mild hypothermia (33°C) after transient focal cerebral ischemia and to ascertain whether the neuroprotective effects of mild hypothermia induced during the ischemic period are sustained over time. Methods. In the first study, rats underwent 2 hours of middle cerebral artery (MCA) occlusion. Animals in one group were maintained under normothermic conditions (N group, 23 rats) throughout the period of ischemia and reperfusion. Rats in four additional groups were exposed to 2 hours of hypothermia, which commenced at ischemia onset (H0 group, 11 rats) or with delays of 90 (H90 group, 10 rats), 120 (H120 group, 10 rats), or 180 (H180 group, five rats) minutes, and allowed to survive for 3 days. In the second study, animals underwent 1.5 hours of MCA occlusion and were maintained under normothermic (48 rats) or hypothermic (44 rats) conditions during the ischemia period, after which they survived for 3 days, 1 week, or 2 mont...