32 results on '"Pravdenkova S"'
Search Results
2. Anterior perforated substance region aneurysms: review of a series treated with microsurgical technique.
- Author
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Basma J, Saad H, Abuelem T, Krisht K, Cai L, Pravdenkova S, and Krisht AF
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- Humans, Retrospective Studies, Surgical Instruments, Treatment Outcome, Intracranial Aneurysm surgery, Subarachnoid Hemorrhage surgery
- Abstract
Aneurysms arising from the distal carotid, proximal A1, and proximal M1 that project posteriorly and superiorly toward the anterior perforated substance (APS) are rare. Their open surgical treatment is particularly difficult due to poorly visualized origin of the aneurysm and the abundance of surrounding perforators. We sought to analyze the anatomical and clinical characteristics of APS aneurysms and discuss surgical nuances that can optimize visualization, complete neck clip obliteration, and preservation of adjacent perforators. Thirty-two patients with 36 APS aneurysms were surgically treated between November 2000 and September 2017. Patients were prospectively enrolled in a cerebral aneurysm database and their clinical, imaging, and surgical records were retrospectively reviewed. Twenty-seven aneurysms originated from the distal ICA, 7 from the proximal A1, and 2 from the proximal M1; 15 patients presented with subarachnoid hemorrhage. Careful intraoperative dissection revealed 4 aneurysms originating at the takeoff of a perforator; another 25 had at least 1 adherent perforator. All aneurysms were clipped except for one that was trapped. Postoperatively, 3 patients had radiographic infarctions in perforator territory with only 1 developing delayed clinical hemiparesis. Good outcome (modified Rankin Scale, 0-2) was achieved in 28 patients (88%). APS aneurysms present a challenging subset of aneurysms due to their complex anatomical relationship with surrounding perforators. These should be identified on preoperative imaging based on location and projection. Successful microsurgical clipping relies on optimization of the surgical view, meticulous clip reconstruction, preservation of all perforators, and electrophysiological monitoring to minimize ischemic complication., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)
- Published
- 2021
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3. Is Falcine Meningioma a Diffuse Disease of the Falx? Case Series and Analysis of a "Grade Zero" Resection.
- Author
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Mooney MA, Abolfotoh M, Bi WL, Tavanaiepour D, Almefty RO, Bassiouni H, Pravdenkova S, Dunn IF, and Al-Mefty O
- Subjects
- Adult, Aged, Dura Mater surgery, Female, Humans, Male, Meningeal Neoplasms mortality, Meningioma mortality, Middle Aged, Neoplasm Grading, Neoplasm Recurrence, Local mortality, Neoplasm Recurrence, Local surgery, Neurosurgical Procedures methods, Progression-Free Survival, Retrospective Studies, Dura Mater pathology, Meningeal Neoplasms pathology, Meningeal Neoplasms surgery, Meningioma pathology, Meningioma surgery, Neoplasm Recurrence, Local pathology
- Abstract
Background: Falcine meningiomas have unique characteristics including their high rates of recurrence, association with high grade pathology, increased male prevalence, and potential for diffuse involvement of the falx., Objective: To address these issues in a substantial series of falcine meningiomas and report on the impact of extent of resection for this distinct meningioma entity., Methods: Retrospective analysis of characteristics and outcomes of 59 falcine meningioma patients who underwent surgery with the senior author. A "Grade Zero" category was used when an additional resection margin of 2 to 3 cm from the tumor insertion was achieved., Results: For de novo falcine meningiomas, gross total resection (GTR) was associated with significantly decreased recurrence incidence compared with subtotal resection (P ≤ .0001). For recurrent falcine meningiomas, median progression-free survival (PFS) was significantly improved for GTR cases (37 mo vs 12 mo; P = .017, hazard ratio (HR) .243 (.077-.774)). "Grade Zero" resection demonstrated excellent durability for both de novo and recurrent cases, and PFS was significantly improved with "Grade Zero" resection for recurrent cases (P = .003, HR 1.544 (1.156-2.062)). The PFS benefit of "Grade Zero" resection did not achieve statistical significance over Simpson grade 1 during the limited follow-up period (mean 2.8 yr) for these groups., Conclusion: The recurrence of falcine meningiomas is related to the diffuse presence of tumor between the leaflets of the falx. Increased extent of resection including, when possible, a clear margin of falx surrounding the tumor base was associated with the best long-term outcomes in our series, particularly for recurrent tumors., (Copyright © 2020 by the Congress of Neurological Surgeons.)
- Published
- 2020
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4. Prognostic factors in the surgical treatment of intracanalicular primary optic nerve sheath meningiomas.
- Author
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Rassi MS, Prasad S, Can A, Pravdenkova S, Almefty R, and Al-Mefty O
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- Adult, Aged, Female, Humans, Male, Meningeal Neoplasms complications, Meningeal Neoplasms diagnostic imaging, Meningioma complications, Meningioma diagnostic imaging, Middle Aged, Optic Nerve Neoplasms complications, Optic Nerve Neoplasms diagnostic imaging, Prognosis, Retrospective Studies, Treatment Outcome, Vision Disorders diagnostic imaging, Vision Disorders etiology, Meningeal Neoplasms surgery, Meningioma surgery, Optic Nerve Neoplasms surgery, Vision Disorders surgery
- Abstract
Objective: Although meningiomas frequently involve the optic nerve, primary optic nerve sheath meningiomas (ONSMs) are rare, accounting for only 1% of all meningiomas. Given the high risk of vision loss with these tumors, surgical intervention is seldom considered, and radiation or observation is commonly applied. Here, the authors describe the visual outcomes for a series of patients who were treated with surgery aiming at maximal tumor resection and highlight their prognostic factors., Methods: The authors retrospectively analyzed the data for 8 patients with intracanalicular ONSMs who had been surgically treated by the senior author (O.A.) between 1998 and 2016. Meningiomas extending into the optic canal from the intracranial cavity (i.e., clinoid, sphenoid wing, tuberculum sellae, diaphragma sellae) were excluded. Diagnosis was based on ophthalmological, radiological, and intraoperative findings, which were confirmed by the typical histological findings. Preoperative, postoperative, and follow-up visual assessments were performed by neuro-ophthalmologists in all cases., Results: The patients included 7 females and 1 male. The mean age at diagnosis was 45.1 years (range 25.0-70.0 years). Mean duration of follow-up was 38.9 months (range 3.0-88.0 months). All patients reported visual complaints, and all had objective evidence of optic nerve dysfunction. Their evaluation included visual field, visual acuity, funduscopy, and retinal fiber thickness. Total resection was obtained in 4 cases. Comparing preoperative and postoperative visual function revealed that 4 patients had improvement at the last follow-up, 1 patient had stable vision, and 3 patients had decreased function but none had total vision loss. All patients with good preoperative visual acuity maintained this status following surgical treatment. There was no surgical mortality or infection. Operative complications included binocular diplopia in 4 patients, which remitted spontaneously., Conclusions: Surgery can play a beneficial role in the primary treatment of ONSM, especially lesions located in the posterior third of the nerve. Total removal can be achieved with vision preservation or improvement, without major surgical complications, especially at early stages of the disease. Patients with good preoperative vision and CSF flow in the optic sheath have better chances of a favorable outcome than those with poor vision.
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- 2018
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5. Pediatric Clival Chordoma: A Curable Disease that Conforms to Collins' Law.
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Rassi MS, Hulou MM, Almefty K, Bi WL, Pravdenkova S, Dunn IF, Smith TR, and Al-Mefty O
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- Child, Child, Preschool, Humans, Infant, Progression-Free Survival, Retrospective Studies, Chordoma diagnosis, Chordoma epidemiology, Chordoma mortality, Chordoma therapy, Skull Base Neoplasms diagnosis, Skull Base Neoplasms epidemiology, Skull Base Neoplasms mortality, Skull Base Neoplasms therapy
- Abstract
Background: Skull base chordomas in children are extremely rare. Their course, management, and outcome have not been defined., Objective: To describe the preeminent clinical and radiological features in a series of pediatric patients with skull base chordomas and analyze the outcome of a cohort who underwent uniform treatment. We emphasize predictors of overall survival and progression-free survival, which aligns with Collins' law for embryonal tumors., Methods: Thirty-one patients with a mean age of 10.7 yr (range 0.8-22) harboring skull base chordomas were evaluated. We retrospectively analyzed the outcomes and prognostic factors for 18 patients treated by the senior author, with uniform management of surgery with the aim of gross total resection and adjuvant proton-beam radiotherapy. Mean follow-up was 119.2 mo (range 8-263)., Results: Abducens nerve palsy was the most common presenting symptom. Imaging disclosed large tumors that often involve multiple anatomical compartments. Patients undergoing gross total resection had significantly increased progression-free survival (P = .02) and overall survival (P = .05) compared with those having subtotal resection. Those who lived through the period of risk for recurrence without disease progression had a higher probability of living entirely free of progression (P = .03; odds ratio = 16.0). Age, sex, and histopathological variant did not yield statistical significance in survival., Conclusion: Long-term overall and progression-free survival in children harboring skull base chordomas can be achieved with gross surgical resection and proton-beam radiotherapy, despite an advanced stage at presentation. Collins' law does apply to pediatric skull base chordomas, and children with this disease have a high hope for cure.
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- 2018
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6. Giant intracranial epidermoids: is total removal feasible?
- Author
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Aboud E, Abolfotoh M, Pravdenkova S, Gokoglu A, Gokden M, and Al-Mefty O
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- Adolescent, Adult, Age Factors, Aged, Brain Neoplasms epidemiology, Brain Neoplasms pathology, Child, Endoscopy methods, Epidermal Cyst epidemiology, Epidermal Cyst pathology, Female, Follow-Up Studies, Humans, Magnetic Resonance Imaging, Male, Microsurgery methods, Middle Aged, Neoplasm Recurrence, Local, Treatment Outcome, Young Adult, Brain Neoplasms surgery, Epidermal Cyst surgery, Neurosurgical Procedures methods
- Abstract
Object: Epidermoid tumors arise from misplaced squamous epithelium and enlarge through the accumulation of desquamated cell debris. Optimal treatment consists of total removal of the capsule; therefore, giant and multicompartmental tumors are particularly challenging. A conservative attitude in handling the tumor capsule is common given concerns about capsule adherence to neurovascular structures, and thus the possibility of recurrence is accepted with the intent of minimizing complications. This study focuses on the outcome of surgery in patients with giant epidermoid tumors for which total capsule removal was the aim., Methods: The authors conducted a retrospective analysis of all patients with giant epidermoid tumors treated by the senior author (O.A.), who pursued total removal of the capsule through skull base approaches. Patients were divided into 2 groups: one including patients with de novo tumors and the other consisting of patients who presented with recurrent tumors., Results: Thirty-four patients had undergone 46 operations, and the senior author performed 38 of these operations in the study period. The average tumor dimensions were 55 × 36 mm, and 25 tumors had multicompartmental extensions. Total removal of the tumor and capsule was achieved with the aid of the microscope in 73% of the 26 de novo cases but in only 17% of the 12 recurrent tumor cases. The average follow-up among all patients was 111 months (range 10-480 months), and the average postsurgical follow-up was 56.8 months (range 6-137 months). There were 4 recurrences in the de novo group, and every case had had a small piece of tumor capsule left behind. One patient died after delayed rupture of a pseudoaneurysm. In the de novo group, the average preoperative Karnofsky Performance Scale (KPS) score was 71.42%, which improved to 87.14% on long-term follow-up. In the group with recurrences, the KPS score also improved on long-term follow-up, from 64.54% to 84.54%. In the de novo group, 3 cases (11.5%) had permanent cranial nerve deficits, and 4 cases (15.4%) had a CSF leak. In the recurrence group, 3 cases (25%) had new, permanent cranial nerve deficits, and 1 (8.3%) had a CSF leak. Two patients in this group developed hydrocephalus and required a shunt., Conclusions: Total removal of the capsule of giant epidermoid tumors was achieved in 73% of patients with de novo tumors and was associated with improved function, low morbidity and mortality, and a lower risk of recurrence. Surgery in patients with recurrent tumors was associated with higher morbidity and persistence of the disease.
- Published
- 2015
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7. Medial acoustic neuromas: clinical and surgical implications.
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Dunn IF, Bi WL, Erkmen K, Kadri PA, Hasan D, Tang CT, Pravdenkova S, and Al-Mefty O
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- Aged, Facial Nerve physiopathology, Female, Humans, Male, Middle Aged, Neuroma, Acoustic pathology, Neuroma, Acoustic physiopathology, Neurosurgical Procedures adverse effects, Neurosurgical Procedures methods, Retrospective Studies, Treatment Outcome, Facial Nerve surgery, Neuroma, Acoustic surgery
- Abstract
Object: Medial acoustic neuroma is a rare entity that confers a distinct clinical syndrome. It is scarcely discussed in the literature and is associated with adverse features. This study evaluates the clinical and imaging features, pertinent surgical challenges, and treatment outcome in a large series of this variant. The authors postulate that the particular pathological anatomy with its arachnoidal rearrangement has a profound implication on the surgical technique and outcome., Methods: The authors conducted a retrospective analysis of 52 cases involving 33 women and 19 men who underwent resection of medial acoustic neuromas performed by the senior author (O.A.) over a 20-year period (1993-2013). Clinical, radiological, and operative records were reviewed, with a specific focus on the neurological outcomes and facial nerve function and hearing preservation. Intraoperative findings were analyzed with respect to the effect of arachnoidal arrangement on the surgeon's ability to resect the lesion and the impact on postoperative function., Results: The average tumor size was 34.5 mm (maximum diameter), with over 90% of tumors being 25 mm or larger and 71% being cystic. Cerebellar, trigeminal nerve, and facial nerve dysfunction were common preoperative findings. Hydrocephalus was present in 11 patients. Distinguishing intraoperative findings included marked tumor adherence to the brainstem and frequent hypervascularity, which prompted intracapsular dissection resulting in enhancement on postoperative MRI in 18 cases, with only 3 demonstrating growth on follow-up. There was no mortality or major postoperative neurological deficit. Cerebrospinal fluid leak was encountered in 7 patients, with 4 requiring surgical repair. Among 45 patients who had intact preoperative facial function, only 1 had permanent facial nerve paralysis on extended follow-up. Of the patients with preoperative Grade I-II facial function, 87% continued to have Grade I-II function on follow-up. Of 10 patients who had Class A hearing preoperatively, 5 continued to have Class A or B hearing after surgery., Conclusions: Medial acoustic neuromas represent a rare subgroup whose site of origin and growth patterns produce a distinct clinical presentation and present specific operative challenges. They reach giant size and are frequently cystic and hypervascular. Their origin and growth pattern lead to arachnoidal rearrangement with marked adherence against the brainstem, which is critical in the surgical management. Excellent surgical outcome is achievable with a high rate of facial nerve function and attainable hearing preservation. These results suggest that similar or better results may be achieved in less complex tumors.
- Published
- 2014
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8. Mobilization of the transcavernous oculomotor nerve during basilar aneurysm surgery: biomechanical bases for better outcome.
- Author
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Basma J, Ryttlefors M, Latini F, Pravdenkova S, and Krisht A
- Subjects
- Biomechanical Phenomena, Diplopia etiology, Diplopia therapy, Female, Follow-Up Studies, Humans, Male, Middle Aged, Models, Neurological, Motion, Oculomotor Nerve Diseases etiology, Recovery of Function, Time Factors, Treatment Outcome, Basilar Artery, Intracranial Aneurysm surgery, Neurosurgical Procedures adverse effects, Oculomotor Nerve anatomy & histology, Oculomotor Nerve physiology
- Abstract
Background: The transcavernous approach adds a significant exposure advantage in basilar aneurysm surgery. However, one of its frequently reported side effects is postoperative oculomotor nerve palsy., Objective: To present the technique of mobilizing the oculomotor nerve throughout its intracranial course and to analyze its consequences on the nerve tension and clinical outcome., Methods: The oculomotor nerve is mobilized from its mesencephalic origin to the superior orbital fissure. Its degree of mobility, related to the imposed pulling force, was measured in 11 cadaveric nerves. Tension was mathematically deduced and compared before and after mobilizing of the cavernous segment. One hundred four patients treated for basilar aneurysms with the orbitozygomatic pretemporal transcavernous approach were followed up for a 1-year period and evaluated for postoperative oculomotor nerve palsy., Results: Releasing the transcavernous segment compared to cisternal mobilization alone resulted in a significant increase in freedom of mobility from 4 to 7.9 mm (P < .001) and in a significant decrease in tension from 0.8 to 0.5 N (P = .006). Ninety-nine percent of aneurysms treated with this technique were amenable to neck clipping, and a total of 84% of patients had a good postoperative outcome (modified Rankin Scale score, 0-2). All patients showed direct postoperative palsy; however, 97% had a complete recovery by 9 months. Only 3 patients had a persistent diplopia on medial gaze, which was corrected with prism glasses., Conclusion: Mobilization of the transcavernous oculomotor nerve results in better maneuverability and less tension on the nerve, which lead to successful surgical treatment and favorable oculomotor outcome.
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- 2014
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9. True petroclival meningiomas: results of surgical management.
- Author
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Almefty R, Dunn IF, Pravdenkova S, Abolfotoh M, and Al-Mefty O
- Subjects
- Adult, Aged, Cranial Fossa, Posterior pathology, Female, Humans, Karnofsky Performance Status, Male, Meningeal Neoplasms pathology, Meningioma pathology, Middle Aged, Neurosurgical Procedures, Petrous Bone pathology, Retrospective Studies, Skull Base Neoplasms pathology, Treatment Outcome, Cranial Fossa, Posterior surgery, Meningeal Neoplasms surgery, Meningioma surgery, Petrous Bone surgery, Skull Base Neoplasms surgery
- Abstract
Object: The relentless natural progression of petroclival meningiomas mandates their treatment. The management of these tumors, however, is challenging. Among the issues debated are goals of treatment, outcomes, and quality of life, appropriate extent of surgical removal, the role of skull base approaches, and the efficacy of combined decompressive surgery and radiosurgery. The authors report on the outcome in a series of patients treated with the goal of total removal., Methods: The authors conducted a retrospective analysis of 64 cases of petroclival meningiomas operated on by the senior author (O.A.) from 1988 to 2012, strictly defined as those originating medial to the fifth cranial nerve on the upper two-thirds of the clivus. The patients' average age was 49 years; the average tumor size (maximum diameter) was 35.48 ± 10.09 mm (with 59 tumors > 20 mm), and cavernous sinus extension was present in 39 patients. The mean duration of follow-up was 71.57 months (range 4-276 months)., Results: In 42 patients, the operative reports allowed the grading of resection. Grade I resection (tumor, dura, and bone) was achieved in 17 patients (40.4%); there was no recurrence in this group (p = 0.0045). Grade II (tumor, dura) was achieved in 15 patients (36%). There was a statistically significant difference in the rate of recurrence with respect to resection grade (Grades I and II vs other grades, p = 0.0052). In all patients, tumor removal was classified based on postoperative contrast-enhanced MRI, and gross-total resection (GTR) was considered to be achieved if there was no enhancement present; on this basis, GTR was achieved in 41 (64%) of 64 patients, with a significantly lower recurrence rate in these patients than in the group with residual enhancement (p = 0.00348). One patient died from pulmonary embolism after discharge. The mean Karnofsky Performance Status (KPS) score was 85.31 preoperatively (median 90) and improved on follow-up to 88, with 30 patients (47%) having an improved KPS score on follow-up. Three patients suffered a permanent deficit that significantly affected their KPS. Cerebrospinal fluid leak occurred in 8 patients (12.5%), with 2 of them requiring exploration. Eighty-nine percent of the patients had cranial nerve deficits on presentation; of the 54 patients with more than 2 months of follow-up, 21 (32.8%) had persisting cranial nerve deficits. The overall odds of permanent cranial nerve deficit of treated petroclival meningioma was 6.2%. There was no difference with respect to immediate postoperative cranial nerve deficit in patients who had GTR compared with those who had subtotal resection., Conclusions: Total removal (Grade I or II resection) of petroclival meningiomas is achievable in 76.4% of cases and is facilitated by the use of skull base approaches, with good outcome and functional status. In cases in which circumstances prevent total removal, residual tumors can be followed until progression is evident, at which point further intervention can be planned.
- Published
- 2014
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10. Sequelae of autologous fat graft used for reconstruction in skull base surgery.
- Author
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Taha AN, Almefty R, Pravdenkova S, and Al-Mefty O
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- Adolescent, Adult, Aged, Female, Foramen Magnum surgery, Glomus Jugulare Tumor surgery, Humans, Magnetic Resonance Imaging, Male, Meningioma surgery, Meningitis etiology, Middle Aged, Neoplasm Recurrence, Local surgery, Neurosurgical Procedures adverse effects, Postoperative Complications cerebrospinal fluid, Postoperative Complications epidemiology, Postoperative Complications pathology, Protons, Reoperation, Retrospective Studies, Skull Base Neoplasms radiotherapy, Skull Base Neoplasms surgery, Treatment Outcome, Young Adult, Adipose Tissue transplantation, Neurosurgical Procedures methods, Skull Base surgery
- Abstract
Background: The use of an autologous free fat graft is a widely applied technique to obliterate dead space and reinforce dural closure during skull base reconstructions. The associated complications and outcomes of this practice have not been studied. Dissemination of fat in the subarachnoid space resulting in lipoid meningitis has been reported after translabyrinthine approaches, and leakage of liquefied fat is seldom reported in the literature. This study aims to evaluate the morbidity associated with the usage of autologous fat graft in reconstruction of skull base defects based on an extensive experience., Methods: This study is a retrospective review of 1581 cases in which the senior author (O.A.) used a skull base approach for the resection of tumor. Autologous fat grafts were used for reconstruction in 974 cases and 10 cases (male to female ratio, 4:6) in which there were associated complications were analyzed., Results: Complications included leakage of sterile liquefied fat from fistula (patients 1, 2, 3), delayed cerebrospinal fluid leak after radiation (Patients 5, 6, 9), and postoperative lipoid meningitis (Patients 4, 7, 8, 10). The onset ranged from 11 days to 10 years. Four patients were managed conservatively, and the other six required surgical intervention. All patients had good outcomes after treatment., Conclusions: The use of autologous fat is associated with a 1% complication rate and should be considered a safe and effective method for skull base reconstruction. However, neurosurgeons should be aware of early and late complications of fat necrosis, including sterile liquefied fat fistula, cerebrospinal fluid leakage, and lipoid meningitis., (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Published
- 2011
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11. Meningiomas involving the optic canal: pattern of involvement and implications for surgical technique.
- Author
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Taha AN, Erkmen K, Dunn IF, Pravdenkova S, and Al-Mefty O
- Subjects
- Adult, Aged, Decompressive Craniectomy adverse effects, Decompressive Craniectomy methods, Female, Humans, Magnetic Resonance Imaging, Male, Meningeal Neoplasms complications, Meningioma complications, Middle Aged, Neurosurgical Procedures adverse effects, Optic Nerve Diseases etiology, Optic Nerve Diseases surgery, Postoperative Complications physiopathology, Retrospective Studies, Treatment Outcome, Vision Disorders etiology, Visual Acuity physiology, Meningeal Neoplasms surgery, Meningioma surgery, Neurosurgical Procedures methods, Sella Turcica surgery, Sphenoid Bone surgery
- Abstract
Object: Juxtasellar meningiomas frequently extend into the optic canal. Removing these meningiomas from the optic canal is crucial for favorable visual outcome., Methods: The authors performed a retrospective analysis of 45 patients with anterior and middle fossa meningiomas with involvement of the optic pathway in whom surgery was performed by the senior author (O.A.M.) during the period from 1993 to 2007. Extent of resection and recurrence rates were determined by pre- and postoperative MR imaging studies. Visual outcomes were evaluated with full ophthalmological examinations performed before and after surgery., Results: Forty-five patients (31 women and 14 men) were involved in this study; their mean age was 51.6 years. Patients were followed for a mean of 29.8 months (range 6-108 months). No surgery-related death occurred. The average tumor size was 3.1 cm. Total resection of the tumor (Simpson Grade I) was achieved in 32 patients (71.1%). Gross-total resection (Simpson Grades II and III) was achieved in 13 patients (28.9%). Only 1 patient harboring a left cavernous sinus meningioma had tumor recurrence and underwent repeat resection. Meningiomas extended into 58 optic canals in these cases; 13 patients showed extension into both optic canals. Visual disturbance was the main presenting symptom in 37 patients (82.2%); 8 patients had normal vision initially. Visual improvement after surgery was seen in 21 (57%) of 37 patients and in 27 (34.6%) of 78 affected eyes. Vision remained unchanged in 48 (61.5%) of 78 eyes. Transient postoperative visual deterioration occurred in 2 eyes (2.6%), with recovery to baseline over time. Only 1 (1.3%) of 78 eyes had permanent visual deterioration after surgery. The visual outcome was affected mainly by the tumor size, the preoperative visual status, and the duration of symptoms., Conclusions: Involvement of the optic canal in meningiomas is frequent. It occurs in a wide variety of anterior skull base meningiomas and it can be bilateral. It is a prominent factor that affects the preoperative visual status and postoperative recovery. Decompression of the optic canal and removal of the tumor inside is a crucial step in the surgical management of these tumors to optimize visual recovery and prevent tumor recurrence.
- Published
- 2011
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12. A technical note on endonasal combined microscopic endoscopic with free head navigation technique of removal of pituitary adenomas.
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Al-Mefty O, Pravdenkova S, and Gragnaniello C
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- Adenoma diagnosis, Cadaver, Equipment Design, Humans, Magnetic Resonance Imaging, Pituitary Neoplasms diagnosis, Sphenoid Sinus surgery, Adenoma surgery, Microscopy, Nasal Cavity surgery, Neuroendoscopy methods, Neuronavigation instrumentation, Pituitary Neoplasms surgery
- Abstract
Pituitary surgery exemplifies the continuous refinement of surgical techniques. The transsphenoidal approach is the approach of choice to treat most pituitary adenomas. We report here, as a technical note, an operative nuance that represents an encompassment of various technical steps that we utilize in our current surgery, including the corroboration of navigation system on a free head with combined use of endoscope and microscope techniques.
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- 2010
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13. The posterior petrosal approach: technique and applications in pediatric neurosurgery.
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Klimo P Jr, Browd SR, Pravdenkova S, Couldwell WT, Walker ML, and Al-Mefty O
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- Adolescent, Brain Neoplasms diagnosis, Child, Child, Preschool, Chordoma diagnosis, Chordoma surgery, Craniopharyngioma diagnosis, Craniopharyngioma surgery, Female, Follow-Up Studies, Ganglioglioma diagnosis, Ganglioglioma surgery, Germinoma diagnosis, Germinoma surgery, Humans, Infant, Magnetic Resonance Imaging, Male, Mastoid surgery, Meningeal Neoplasms diagnosis, Meningeal Neoplasms surgery, Neurilemmoma diagnosis, Neurilemmoma surgery, Pituitary Neoplasms diagnosis, Pituitary Neoplasms surgery, Postoperative Complications diagnosis, Postoperative Complications etiology, Young Adult, Brain Neoplasms surgery, Craniotomy methods, Petrous Bone surgery
- Abstract
Object: Various lesions occur in deep locations or at the skull base in pediatric patients and require skull base approaches for resection. Skull base surgery confers the advantages of improved line of sight, a wider operative corridor, and reduced brain retraction. The posterior petrosal approach provides simultaneous access to lesions in the posterior middle fossa and posterior fossa from the top of the clivus to the level of the jugular foramen. It allows visualization of the ventrolateral brainstem and may be combined with various other supra- and infratentorial approaches, thus giving the surgeon a wide array of access routes to the lesion., Methods: The authors conducted a retrospective review of all cases involving pediatric patients undergoing a posterior petrosal approach, either alone or in combination with other cranial approaches. Preoperative and postoperative data were collected, including presentation, neurological examination, imaging findings, pathological condition, operative details, perioperative complications, and postoperative outcomes., Results: There were 13 patients (6 female, 7 male) with a mean age of 12.6 years (range 14 months-9 years). The posterior petrosal was the sole skull base cranial approach in 4 patients, whereas the posterior petrosal was combined with 1 or more other cranial approaches in 9. A gross-total resection was achieved in 7 patients, subtotal resection in 5, and a biopsy was performed in 1. Complications occurred in 9 patients, including 7 new or worsened cranial neuropathies. There was no perioperative mortality., Conclusions: Although infrequently used in pediatric neurosurgery, the posterior petrosal approach is a highly versatile approach that can access intra- and extraaxial pathology centered on the petrous bone. The authors believe that patient outcomes are directly related to the degree of experience using this approach. Therefore, if this approach is to be used, they recommend collaboration with a skull base neurosurgeon.
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- 2009
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14. Impact of cytogenetic abnormalities on the management of skull base chordomas.
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Almefty KK, Pravdenkova S, Sawyer J, and Al-Mefty O
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- Adult, Chordoma mortality, Chromosome Aberrations, Disease Progression, Female, Humans, Male, Neoplasm Recurrence, Local, Skull Base Neoplasms mortality, Chordoma genetics, Karyotyping, Skull Base Neoplasms genetics
- Abstract
Object: Cytogenetic studies of chordomas are scarce and show multiple changes involving different chromosomes. These abnormalities are implicated in the pathogenesis of chordoma, but the clinical significance of these changes is yet to be determined. In this study, the authors discuss the cytogenetic changes in a large series of skull base chordomas with long-term follow-up and focus on the impact of these changes on the prognosis, progression, and management of the disease., Methods: The karyotypes of chordomas in 64 patients (36 men and 28 women) were studied in relation to survival and recurrence or progression over a mean follow-up period of 48 +/- 37.5 months. The standard G-banding technique was used for karyotype analysis. Statistical analysis was performed with the Fisher exact test and ORs, and Kaplan-Meier curves were generated for survival and recurrence/progression of disease., Results: Seventy-four percent of de novo chordomas had normal karyotypes and a 3% recurrence rate; there was a 45% recurrence rate in de novo tumors with abnormal karyotypes (p < 0.01). Recurrent tumors were associated with a high incidence of abnormal karyotype (75%). The OR for recurrence in lesions with an abnormal versus a normal karyotype was 12. Aberrations in chromosomes 3, 4, 12, 13, and 14 were associated with frequent recurrence and decreased survival time. Ninety-five percent of cases with progression involved chromosome 3 and/or 13. The median survival time was 4 months when both of these chromosomes had aberrations (p = 0.02)., Conclusions: Chordomas with normal karyotypes were associated with a low rate of recurrence and a long patient survival, and recurrent chordomas were associated with an abnormal karyotype, disease progression, and poor survival. De novo chordomas with normal karyotypes may be amenable to radical resection and adjunctive proton beam therapy. Recurrent and de novo chordomas with abnormal karyotypes were associated with complex cytogenetic abnormalities and a poor prognosis, particularly in the presence of aberrations underlying tumor progression in chromosomes 3, 4, 12, 13, and 14.
- Published
- 2009
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15. Anterior clivectomy: surgical technique and clinical applications.
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Al-Mefty O, Kadri PA, Hasan DM, Isolan GR, and Pravdenkova S
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- Adolescent, Adult, Aged, Cerebrospinal Fluid, Child, Child, Preschool, Female, Humans, Male, Middle Aged, Neuronavigation methods, Retrospective Studies, Skull Base surgery, Skull Base Neoplasms surgery, Sphenoid Sinus surgery, Young Adult, Cranial Fossa, Posterior surgery, Minimally Invasive Surgical Procedures methods, Neurosurgical Procedures methods
- Abstract
Object: Midline clival lesions, whether involving the clivus or simply situated anterior to the brainstem, present a technical challenge for adequate exposure and safe resection. The authors describe, as a minimally invasive technique, an anterior clivectomy performed via an expanded transsphenoidal approach coupled with the use of a neuronavigation on mobile head and endoscopic-assisted technique. Wide and direct exposure, with the ability to resect extra- and intradural tumors, was achieved without mortality and with a low rate of complications., Methods: Cadaveric dissections were performed to outline the landmarks and measure the window that is created by resecting the clivus anteriorly. The technique was used in 43 patients to resect tumors located at or invading the clivus. The initial exposure of the clivus was obtained via the sublabial transsphenoidal approach. The wall of the anterior maxilla, often on 1 side, was removed to allow a wide side-to-side opening of the nasal speculum. Using neuronavigation, the authors made clivectomy windows by drilling the clivus between anatomical landmarks. Bilateral intraoperative neurophysiological monitoring was used (somatosensory evoked potentials, brainstem auditory evoked responses, and cranial nerves VI-XII)., Results: Of the 43 patients, 26 were female and 17 were male, and they ranged in age from 3.5 to 76 years (mean 41.5 years). Thirty-eight patients harbored a chordoma and 5 a giant invasive pituitary adenoma. Gross-total resection of the tumor was achieved in 34 cases (79%). Nine patients (21%) had residual tumor unreachable through the anterior clivectomy, and this required a second-stage resection. Four patients developed new transient extraocular movement deficits. One patient developed a permanent cranial nerve VI palsy. Twenty-seven patients with chordoma underwent postoperative proton-beam radiotherapy. Tumor recurred in 19% of these cases. In 3 patients a cerebrospinal fluid leak developed during hospitalization and was treated successfully. Two other patients presented with a delayed cerebrospinal fluid leak after radiotherapy. Only 1 patient, who had previously undergone Gamma Knife surgery, experienced postoperative hemiparesis., Conclusions: A complete anterior clivectomy via a simple extension of the transsphenoidal approach allows the surgeon access to different lesions involving the clivus or situated anterior to the brainstem. The exposure is similar to that provided by more extensive transfacial approaches. Instrument manipulation is easy. Neuronavigation, endoscopy, and intraoperative monitoring are easily incorporated and enhance the capability and safety of this approach.
- Published
- 2008
- Full Text
- View/download PDF
16. Chordoma and chondrosarcoma: similar, but quite different, skull base tumors.
- Author
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Almefty K, Pravdenkova S, Colli BO, Al-Mefty O, and Gokden M
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Child, Child, Preschool, Chondrosarcoma pathology, Chondrosarcoma radiotherapy, Chondrosarcoma surgery, Chordoma pathology, Chordoma radiotherapy, Chordoma surgery, Female, Humans, Infant, Male, Middle Aged, Neoplasm Recurrence, Local, Retrospective Studies, Skull Base Neoplasms pathology, Skull Base Neoplasms radiotherapy, Skull Base Neoplasms surgery, Treatment Outcome, Chondrosarcoma diagnosis, Chordoma diagnosis, Skull Base Neoplasms diagnosis
- Abstract
Background: Chordoma and chondrosarcoma of the skull base are frequently amalgamated because of similar anatomic location, clinical presentation, and radiologic findings. The chondroid chordoma variant has been reported to carry a better prognosis. The objective of the current study was to investigate the distinctions between these 3 entities., Methods: The data concerning 109 patients with chordoma, chondroid chordoma, and chondrosarcoma who were treated by a single surgeon with maximum surgical resection and frequently by adjunct proton beam radiotherapy between 1990 and 2006 were analyzed retrospectively. Pathologic distinction was established by cytokeratin and epithelial membrane antigen staining. Clinical, radiologic, pathologic, and cytogenetic studies were analyzed in relation to disease recurrence and death., Results: The average follow-up was 48+/-37.5 months (range, 1-191 months). There were no reliable distinguishing clinical or radiologic features noted between the groups. Chondrosarcoma patients had a significantly better outcome compared with chordoma patients with regard to survival and recurrence-free survival (P=.028 and P<.001, respectively), whereas patients with chondroid chordoma had a poor outcome similar to chordoma patients with regard to survival and recurrence-free survival (P=.337 and P=.906, respectively)., Conclusions: Chordoma and chondrosarcoma differ with regard to their origin and histology, and differ markedly with regard to outcome. Chondroid chordomas behave in a manner that is clinically similar to chordomas, with the same prognosis. Both chordoma types demonstrate an aggressive clinical course and poor outcome after disease recurrence. The optimal treatment for all groups of patients involves radical surgical resection followed by high-dose radiotherapy in patients with chordomas. Radiotherapy may not be necessary in patients with low-grade chondrosarcoma., (Copyright (c) 2007 American Cancer Society.)
- Published
- 2007
- Full Text
- View/download PDF
17. De novo versus transformed atypical and anaplastic meningiomas: comparisons of clinical course, cytogenetics, cytokinetics, and outcome.
- Author
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Krayenbühl N, Pravdenkova S, and Al-Mefty O
- Subjects
- Adolescent, Adult, Aged, Female, Humans, Male, Middle Aged, Retrospective Studies, Treatment Outcome, Brain Neoplasms genetics, Brain Neoplasms pathology, Cytogenetic Analysis methods, Meningioma genetics, Meningioma pathology
- Abstract
Objective: The clinical course of atypical and anaplastic meningiomas is heterogeneous. As malignant gliomas, aggressive meningiomas may arise de novo or transform from a benign tumor. This study aims to compare differences in clinical behavior, cytogenetics, cytokinetics, receptor status, and outcome between de novo malignant meningiomas and meningiomas that progressed to malignancy., Methods: Data from 36 patients with atypical or anaplastic meningiomas were selected for retrospective analysis and divided into two subgroups: 1) de novo atypical or anaplastic tumors and 2) tumors that progressed from a lower grade. We analyzed data concerning patients' sex, age, tumor location, number of operations, status of hormone receptors, proliferative indices, cytogenetic findings, additional therapy, and survival. For meningiomas with progression, we calculated the interval between initial diagnosis and tumor progression., Results: For atypical meningiomas, the subgroups had significant differences in status of progesterone receptors, proliferative indices, cytogenetics, and patients' outcome. The anaplastic group had similar differences, but they did not reach statistical significance because of the small numbers. There was a loss of part or monosomy of chromosome 10 and an increased monosomy or derivative chromosome 1 combined with monosomy of chromosome 14. These phenomena occurred mainly in patients with malignant transformation who had a worse outcome., Conclusion: De novo malignant meningiomas and meningiomas with malignant transformation may represent distinct subgroups of atypical and anaplastic meningiomas.
- Published
- 2007
- Full Text
- View/download PDF
18. Progesterone and estrogen receptors: opposing prognostic indicators in meningiomas.
- Author
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Pravdenkova S, Al-Mefty O, Sawyer J, and Husain M
- Subjects
- Adult, Aged, Cell Division genetics, Chromosomes, Human, Pair 14, Chromosomes, Human, Pair 22, Female, Gene Expression Regulation, Neoplastic, Humans, Male, Meningeal Neoplasms diagnosis, Meningeal Neoplasms genetics, Meningeal Neoplasms pathology, Meningioma diagnosis, Meningioma genetics, Meningioma pathology, Middle Aged, Neoplasm Invasiveness pathology, Neoplasm Recurrence, Local genetics, Neoplasm Recurrence, Local pathology, Prognosis, Skull Base pathology, Skull Base surgery, Meningeal Neoplasms surgery, Meningioma surgery, Receptors, Estrogen genetics, Receptors, Progesterone genetics
- Abstract
Object: The preponderance of progesterone receptors (PRs) and the scarcity of estrogen receptors (ERs) in meningiomas are well known. The expression of PRs may relate to tumor grade and recurrence. Cytogenetic abnormalities are associated with aggressive behavior, recurrence, and progression. In this study, the authors focus on the prognostic implications of hormone receptors in meningiomas to help determine the clinical and biological aggressiveness of tumors and their correlations with cytogenetic abnormalities., Methods: Two hundred thirty-nine patients with meningiomas were separated into three groups. Group 1 (PR-positive group) comprised patients whose meningiomas displayed expression of PRs alone. Group 2 (receptor-negative group) included patients whose lesions did not have receptors for either progesterone or estrogen. Group 3 (ER-positive group) included patients whose tumors displayed expression of ERs. Clinical and histological findings, proliferative indices, tumor recurrence, and cytogenetic findings were analyzed by performing the Fisher exact test. Compared with the receptor-negative (Group 2) and ER-positive (Group 3) groups, the PR-positive group (Group 1) had a statistically significant lower proliferative index and a smaller number of patients in whom there were aggressive histopathological findings or changes in karyotype. In Groups 1, 2, and 3, the percentages of cases with aggressive histopathological findings were 10, 31, and 33%, respectively; the percentages of cases with chromosomal abnormalities were 50, 84, and 86%, respectively; and the percentages of cases in which there initially was no residual tumor but recurrence was documented were 5, 30, and 27%, respectively. A statistically significant increase in the involvement of chromosomes 14 and 22 was identified in receptor-negative and ER-positive de novo meningiomas, when compared with the PR-positive group. Abnormalities on chromosome 19 were statistically significantly higher in receptor-negative meningiomas than in PR-positive tumors., Conclusions: The expression of the PR alone in meningiomas signals a favorable clinical and biological outcome. A lack of receptors or the presence of ERs in meningiomas correlates with an accumulation of qualitative and quantitative karyotype abnormalities, a higher proportional involvement of chromosomes 14 and 22 in de novo tumors, and an increasing potential for aggressive clinical behavior, progression, and recurrence of these lesions. Sex hormone receptor status should routinely be studied for its prognostic value, especially in female patients, and should be taken into account in tumor grading. The initial receptor status of a tumor may change in progression or recurrence of tumor.
- Published
- 2006
- Full Text
- View/download PDF
19. Surgical management of petroclival meningiomas: factors determining the choice of approach.
- Author
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Erkmen K, Pravdenkova S, and Al-Mefty O
- Subjects
- Disease Management, Humans, Meningeal Neoplasms pathology, Meningioma pathology, Petrous Bone pathology, Retrospective Studies, Skull Base Neoplasms pathology, Skull Base Neoplasms surgery, Meningeal Neoplasms surgery, Meningioma surgery, Neurosurgical Procedures methods, Petrous Bone surgery
- Abstract
Petroclival meningiomas remain one of the most challenging intracranial tumors to treat surgically. This is attributable to their location deep within the skull base and their association with multiple critical neural and vascular structures. Over the years, many skull base approaches have been described that are meant to improve resection and decrease patient morbidity. Appropriate selection of the surgical approach requires a thorough preoperative evaluation of clinical and radiological factors. In this paper the authors retrospectively reviewed 97 patients treated surgically for petroclival meningiomas by the senior author (O.A.M.) between 1995 and 2005 to assess the factors used to determine the choice of surgical approach, and to assess complication rates based on the approach selected. The skull base approaches used in these patients included the middle fossa anterior petrosal, posterior petrosal, and combined petrosal approaches, and complete petrosectomy. Factors found to be important in determining the selection of approach included the size, location, and extension of the tumor, preoperative hearing evaluation, and venous sinus anatomy.
- Published
- 2005
- Full Text
- View/download PDF
20. Malignant progression in meningioma: documentation of a series and analysis of cytogenetic findings.
- Author
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Al-Mefty O, Kadri PA, Pravdenkova S, Sawyer JR, Stangeby C, and Husain M
- Subjects
- Adult, Aged, Chromosomes, Human, Pair 1 genetics, Chromosomes, Human, Pair 14 genetics, Chromosomes, Human, Pair 22 genetics, Cytogenetics methods, Disease Progression, Documentation methods, Female, Gene Deletion, Humans, In Situ Hybridization, Fluorescence methods, Male, Meningeal Neoplasms surgery, Meningioma surgery, Middle Aged, Neoplasm Recurrence, Local, Neurosurgical Procedures instrumentation, Ki-67 Antigen genetics, Meningeal Neoplasms genetics, Meningeal Neoplasms pathology, Meningioma genetics, Meningioma pathology, Tumor Suppressor Protein p53 genetics
- Abstract
Object: The malignant progression of benign tumors is well documented in gliomas and other systemic lesions. It is also well known that some meningiomas become progressively aggressive despite their original benign status. The theory of clonal evolution is widely believed to explain malignant progression in meningioma; however, the data used to explain stepwise progression have typically been derived from the cytogenetic analysis of different types of tumors of different grades and in different patients. In this study, the authors examined the data obtained in a group of patients with meningiomas that showed clear histopathological progression toward a higher grade of malignancy and then analyzed the underlying cytogenetic findings., Methods: Among 175 patients with recurrent meningiomas, 11 tumors showed a histopathological progression toward a higher grade that was associated with an aggressive clinical course. Six tumors progressed to malignancy and five to the atypical category over a period averaging 112 months. Tests for MIB-1 and p53 and cytogenetic studies with the fluorescence in situ hybridization (FISH) method were performed in successive specimens obtained in four patients. The MIB-1 value increased in subsequent samples of tumors. Cytogenetic analysis with FISH showed deletions of 22, 1p, and 14q. In all but one case, these aberrations were also present in the previous specimen despite its lower hispathological grade., Conclusions: The authors documented the progression of meningiomas from benign to a higher histological grade. These tumors were associated with a complex karyotype that was present ab initio in a histologically lower-grade tumor, contradicting the stepwise clonal evolution model. Although it was limited to the tested probes, the FISH method appears to be more accurate than the standard cytogenetic one in detecting these alterations. Tumors that present with complex genetic alterations, even those with a benign histological grade, are potentially aggressive and require closer follow up.
- Published
- 2004
- Full Text
- View/download PDF
21. Radiation-induced meningiomas: clinical, pathological, cytokinetic, and cytogenetic characteristics.
- Author
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Al-Mefty O, Topsakal C, Pravdenkova S, Sawyer JR, and Harrison MJ
- Subjects
- Adolescent, Adult, Age of Onset, Aged, Child, Child, Preschool, Female, Humans, Infant, Male, Meningeal Neoplasms genetics, Meningioma genetics, Middle Aged, Neoplasms, Radiation-Induced genetics, Prognosis, Receptors, Progesterone analysis, Retrospective Studies, Time Factors, Chromosome Aberrations, Meningeal Neoplasms etiology, Meningeal Neoplasms pathology, Meningioma etiology, Meningioma pathology, Neoplasms, Radiation-Induced pathology
- Abstract
Object: Radiation-induced meningiomas are known to occur after high- and low-dose cranial radiation therapy. The goal of this study was to discern the distinguishing findings and characteristics of radiation-induced meningiomas., Methods: The records of 16 patients (seven men and nine women) who fulfilled the criteria for radiation-induced meningiomas were retrospectively reviewed. Clinical, histopathological, cytokinetic, and cytogenetic findings as well as the patients' outcome were analyzed. The mean age of the patients was 38.8 years and the mean tumor latency was 26.5 years. Five patients had multiple meningiomas in the irradiated field. The recurrence rate was 100% after the initial resection; 62% of patients had a second recurrence and 17% had a third recurrence. Thirty-eight percent of patients had atypical or malignant histopathological findings. The presence of progesterone receptors and low proliferation indices in these patients did not correlate with benign tumor behavior. Cytogenetic analysis showed multiple clonal aberrations in all tumors studied. The most frequent aberrations were found on chromosomes 1p, 6q, and 22. Derivative, lost, or additional chromosome 1p was found in 89% of cases and loss or deletion on chromosome 6 was found in 67%., Conclusions: The age of patients at presentation with meningioma and the latency period of radiation-induced meningiomas are dose related. These tumors are more aggressive and are certain to recur, have a higher histopathological grade, and are associated with complex cytogenetic aberrations particularly involving 1p and 6q.
- Published
- 2004
- Full Text
- View/download PDF
22. A role for telomeric and centromeric instability in the progression of chromosome aberrations in meningioma patients.
- Author
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Sawyer JR, Husain M, Pravdenkova S, Krisht A, and Al-Mefty O
- Subjects
- Adult, Aged, Brain Neoplasms pathology, Chromosomes, Human, Pair 12, Chromosomes, Human, Pair 22, Female, Humans, Karyotyping, Male, Meningioma pathology, Middle Aged, Brain Neoplasms genetics, Centromere genetics, Chromosome Aberrations genetics, Chromosome Breakage, Meningioma genetics, Telomere genetics
- Abstract
Background: The primary chromosome aberration in meningiomas is monosomy or deletion of chromosome 22. Common secondary aberrations include losses or deletions of chromosomes 1p, 14q, and 10q and unstable chromosome aberrations including rings, dicentrics, and telomeric associations. Despite the analysis of several hundred tumors by cytogenetic and molecular techniques, the mechanisms involved in the progression of chromosome aberrations in meningioma remain poorly understood., Methods: Sixty-seven meningiomas were cultured successfully using a short term in situ technique and harvested incorporating a high resolution G-banding technique with ethidium bromide., Results: Twenty-six tumors (39%) showed normal karyotypes, whereas 41 tumors (61%) showed clonal chromosome aberrations. The most frequently observed aberration was the loss of chromosome 22 or structural aberrations involving 22q12, which occurred in 30 tumors (45%). The second most common aberrations were whole arm translocations involving the centromeric breakpoint at 1q10, resulting in the loss of the entire 1p chromosome in 12 tumors (18%). Two tumors showed a new, recurring, unbalanced, whole arm translocation der(1;2)(q10;q10). A third aberration, telomeric associations, were observed in 16 tumors (24%), occurring transiently in 11 tumors and recurring clonally in 5 tumors. Dicentric chromosome 22 was found in 7 tumors (10%), with the progressive loss of chromosome 22q material being found in 2 tumors., Conclusions: The chromosome instability demonstrated in the current series of tumors suggests that the progression of chromosome aberrations in meningioma is mediated in some respects by both telomeric and centromeric instability. These two types of instability may be early events in the progression of chromosome aberrations in meningioma and each can account for at least some of the loss of heterozygosity of chromosomes 22q and 1p detected by molecular analysis., (Copyright 2000 American Cancer Society.)
- Published
- 2000
23. Alteration of opioid peptide concentrations in the rat pituitary following survivable closed head injury.
- Author
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Grigoriants OO, Pravdenkova SV, Andersen BJ, and Desiderio DM
- Subjects
- Animals, Chromatography, High Pressure Liquid methods, Enkephalin, Methionine analysis, Male, Rats, Rats, Sprague-Dawley, Reference Values, Time Factors, beta-Endorphin analysis, Enkephalin, Methionine metabolism, Head Injuries, Closed metabolism, Pituitary Gland metabolism, beta-Endorphin metabolism
- Abstract
Concentration changes of methionine enkephalin-like immunoreactivity (ME-li) and beta-endorphin-like immunoreactivity (BE-li) in the rat pituitary following diffuse brain injury were studied. Closed head injury was induced by a weight-drop trauma device (450 g x 2 m). The level of closed head injury used in this study altered the pituitary opioid peptide concentrations. The level of ME-li did not change in the experimental groups 3 hours, 10 hours, 24 hours, and 3 days after the trauma, but significantly increased by 34% 10 days after the trauma. BE-li remained constant 3 hours and 10 hours following the injury, increased by 48% at 24 hours, and remained at this level for 10 days after the trauma (44% at 3 days, and 40% at 10 days). The levels of ME-li and BE-li in the control sham-operated rats did not change during these times. The present measurements of BE-li and ME-li in the pituitary indicate that the opioid peptides that derive from two different neuropeptidergic systems, proopiomelanocortin (POMC) and preproenkephalin A, respectively, may participate in the pathophysiology of a closed head injury.
- Published
- 1995
- Full Text
- View/download PDF
24. [Effect of hyperbaric oxygenation on respiration in acute cerebral circulatory disorders].
- Author
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Isakov IuV, Pravdenkova SV, and Ioffe IuS
- Subjects
- Adult, Aged, Brain Ischemia physiopathology, Brain Ischemia surgery, Humans, Intracranial Aneurysm physiopathology, Intracranial Aneurysm surgery, Middle Aged, Oxygen Consumption, Postoperative Period, Brain Ischemia therapy, Hyperbaric Oxygenation, Intracranial Aneurysm therapy, Respiration
- Abstract
The OKA-MT pressure chambers were used. External respiration was studied by spirography by means of the SG-2M spirograph. From the results of examination of 53 patients with acute cerebral circulatory disorders it was established that hyperbaric oxygen normalizes the initially abnormal external respiration: corrects the periodical rhythms and reduces hyperventilation; the hyperbaric oxygenation sessions have no effect on initially normal respiration; the reaction of external respiration to hyperbaric oxygen changes during the course of treatment depending on the number of sessions; the appearance or intensification of the hyperventilation syndrome after one or three hyperbaric oxygenation sessions in the absence of negative neurological dynamics cannot be assessed as a contraindication for hyperbarotherapy.
- Published
- 1982
25. [Effect of hyperbaric oxygenation on the clinical course and complications of the acute period of ischemic strokes].
- Author
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Lebedev VV, Isakov IuV, and Pravdenkova SV
- Subjects
- Aphasia prevention & control, Brain Ischemia complications, Humans, Movement Disorders prevention & control, Pneumonia prevention & control, Pulmonary Edema prevention & control, Pulmonary Embolism prevention & control, Recurrence, Unconsciousness prevention & control, Brain Ischemia therapy, Hyperbaric Oxygenation
- Abstract
Hyperbaric oxygenation (HBO) was included in the therapeutic complex for 124 patients in the acute stage of ischemic stroke. The effect of HBO on the clinical course was appraised by comparing the dynamics of changes in the clinical symptoms and the frequency of complications in patients exposed to HBO with those in the control group (patients not exposed to HBO). It was established that the depth of unconsciousness and the motor and aphasic disorders decreased during a HBO session, but the effect was usually short-lived. Aggravation of the patients' condition in the first week of the disease, evidently caused by increase of cerebral edema, occurred much less frequently when HBO was included in the complex of therapeutic measures. The number of patients with regression of the neurological symptoms was practically the same with and without the use of HBO, but the regression of the neurological defects was most evident in patients exposed to HBO. HBO prevents the development of recurrent cerebral circulatory disorders in the acute stage of ischemic stroke and reduces the incidence of some complications in this period (pneumonia, pulmonary edema, thromboembolism of the pulmonary artery, etc.).
- Published
- 1983
26. [Hyperbaric oxygenation in ruptured cerebral aneurysms during the postoperative period].
- Author
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Isakov IuV, Pravdenkova SV, and Shchelkovskiĭ VN
- Subjects
- Adolescent, Adult, Female, Fever prevention & control, Follow-Up Studies, Headache prevention & control, Humans, Male, Meningism prevention & control, Middle Aged, Neurocognitive Disorders prevention & control, Postoperative Care, Postoperative Complications prevention & control, Hyperbaric Oxygenation, Intracranial Aneurysm surgery, Subarachnoid Hemorrhage surgery
- Abstract
The OKA-MT pressure chamber was used. The course consisted of 6-15 sessions at a pressure of 1.6-2.0 at. abs. Hyperbaric oxygenation (HBO) was included in the complex of therapeutic measures applied in the postoperative period in patients with ruptured aneurysms of the cerebral vessels. From comparison of the course of the disease in 47 patients treated by HBO with that in 30 patients not subjected to HBO (control group) the authors conclude that the inclusion of HBO in the complex of measures applied after operations on the cerebral vessels for ruptured aneurysms has a positive effect on the course of the disease: the grave condition is less prolonged; the duration of the meningeal syndrome, headache, and temperature reaction is shorter by 6 days than in the control group; the number of patients with a good result of treatment increases by 18%; mental disorders in the absence of hematoma of the frontal area are prevented; the frequency of suppurations of the postoperative wound diminishes.
- Published
- 1985
27. [Effect of hyperbaric oxygenation on patient hemodynamics and respiration in blood loss as a consequence of gastroduodenal hemorrhages].
- Author
-
Isakov IuV, Uteshev NS, Kusova NN, Pravdenkova SV, and Rasshchepkina NA
- Subjects
- Adolescent, Adult, Aged, Blood Volume, Duodenal Ulcer complications, Gastrointestinal Hemorrhage physiopathology, Humans, Middle Aged, Peptic Ulcer Hemorrhage physiopathology, Peptic Ulcer Hemorrhage therapy, Stomach Ulcer complications, Gastrointestinal Hemorrhage therapy, Hemodynamics, Hyperbaric Oxygenation, Respiration
- Abstract
Hyperbaric oxygenation (HBO) was used in the complex of treatment of 52 patients who had blood loss due to gastroduodenal hemorrhage. Barocameras were used with the maximum pressure of 1.6--2.0 atm for 40 min. 6--10 sessions for a course. The sessions of HBO while reducing hypoxia could eliminate the compensatory hyperfunction of the myocardium and decrease the extra-load on the heart. The external ventilation function was not substantially influenced by the sessions of HBO.
- Published
- 1981
28. [Respiratory and central hemodynamic responses during a session of hyperbaric oxygenation in patients with acute cerebral circulatory disorders].
- Author
-
Isakov IuV and Pravdenkova SV
- Subjects
- Acute Disease, Adult, Brain Ischemia physiopathology, Cardiac Output, Humans, Intracranial Aneurysm surgery, Middle Aged, Oxygen Consumption, Stroke Volume, Vascular Resistance, Cerebrovascular Disorders physiopathology, Hemodynamics, Hyperbaric Oxygenation, Respiration
- Abstract
On the basis of examining the changes of external respiration function and the central circulation in the course of treatment by hyperbaric oxygenation given to 64 patients with acute cerebral circulation disorders the authors have come to the following conclusions: a) patients with acute cerebral circulation disorders may show five types of the response to hyperbaric oxygenation; b) the type of the patient's response to each session may change during the treatment course; c) a prognosis of the response type is usually impossible; d) none of the response types leads to an aggravation of the disease clinical picture; e) the changed external respiration function and the central circulation return in 3 to 4 hours to their initial parameters.
- Published
- 1981
29. [Changes in central hemodynamics in patients with ischemic stroke and possibilities of hyperbaric oxygenation in their correction].
- Author
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Isakov IuV, Pravdenkova SV, and Shelkovskiĭ VN
- Subjects
- Brain Ischemia therapy, Humans, Brain Ischemia physiopathology, Hemodynamics, Hyperbaric Oxygenation
- Published
- 1986
30. [Therapeutic effect of hyperbaric oxygenation in the acute stage of an ischemic stroke].
- Author
-
Pravdenkova SV, Isakov IuV, and Ioffe IuS
- Subjects
- Acute Disease, Adult, Aged, Humans, Middle Aged, Brain Ischemia therapy, Hyperbaric Oxygenation
- Published
- 1983
31. [Hyperbaric oxygenation and prevention of recurrent cerebral circulatory disorders in the acute stage of a stroke].
- Author
-
Pravdenkova SV, Romasenko MV, and Shelkovskiĭ VN
- Subjects
- Acute Disease, Adult, Aged, Brain Ischemia physiopathology, Brain Ischemia prevention & control, Female, Humans, Male, Middle Aged, Myocardial Contraction, Recurrence, Stroke Volume, Brain Ischemia therapy, Hyperbaric Oxygenation
- Abstract
The course of the acute period of cerebral stroke was compared in two groups of patients matched by the major clinical criteria: the test group receiving hyperbaric oxygenation (HBO) and the control one given no such treatment. It was found that the patients of the test group developed no recurrent impairments of the cerebral circulation in the acute period whereas in the control group this complication occurred in ten patients. Possible mechanisms of action of hyperbaric oxygen in preventing recurrent cerebral strokes are discussed.
- Published
- 1984
32. [Effect of hyperbaric oxygenation on central hemodynamics in patients in the acute stage of ischemic stroke].
- Author
-
Isakov IuV and Pravdenkova SV
- Subjects
- Acute Disease, Adult, Aged, Blood Pressure, Cardiac Output, Heart Rate, Humans, Hyperbaric Oxygenation, Middle Aged, Stroke Volume, Vascular Resistance, Vasoconstriction, Brain Ischemia therapy, Hemodynamics
- Abstract
Thirty-two patients with ischemic stroke of various localization were examined. The method of tetropolar rheography was used; 300 tetrapolar rheograms were recorded. The patients were examined before, immediately after, and 2--3 hours after the hyperbaric oxygenation session; the haemodynamics were studied several times during the course. On the grounds of the study carried out, the authors conclude that in most patients the first HBO sessions cause a general vasoconstricting effect and lead to a decrease in the cardiac output; the next sessions normalize the initially abnormal hemodynamics; the HBO sessions hardly cause any changes in arterial pressure, in patients with vertebrobasilar pathology, however, a mild elevation of systolic and mean pressure was recorded after the sessions; hyperbaric oxygen reduces the rate of cardiac contractions by 9% irrespective of the initial pulse rate.
- Published
- 1980
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