P Sampath

Johns Hopkins Medicine, Baltimore, MD, United States

Are you P Sampath?

Claim your profile

Publications (23)69.83 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Combined craniofacial resection has become the standard approach for malignant tumors involving the cribriform plate and anterior cranial fossa. Despite its widespread application, however, many surgeons agree that the procedure carries a risk of significant morbidity and even mortality. The purpose of this study was to analyze the experience at a single institution to determine the incidence of early postoperative complications encountered after combined craniofacial resection of tumors involving the cribriform plate and to provide information to improve management. Between 1987 and 1997, 168 patients underwent combined craniofacial resection at the National Cancer Institute of Milan for tumors involving the cribriform plate. Patient charts, operative notes, follow-up clinic notes, radiographic studies, and pathology reports were analyzed. Morbidity encountered in the first 30 cases was compared with that encountered in the subsequent 138 cases. The most frequently encountered pathological findings were adenocarcinoma (53.6%), squamous cell carcinoma (17%), and esthesioneuroblastoma (9.8%). Eight patients (4.7%) died, 6 of whom were among the first 30 patients to undergo resection. Among patients with fatal complications were three with meningoencephalitis, three with intracranial hemorrhage, and one with myocardial infarction. Fifty patients (29.7%) had nonfatal morbidity; 16 of these patients were among the first 30 patients operated. Transient cerebrospinal fluid leakage was the most frequent adverse effect (9.5%); 12 patients (7.1%) had pneumocephalus, 3 (1.8%) had meningitis, 4 (2.4%) had wound infections, 3 (1.8%) experienced transient impairment of mental status, 3 (1.8%) had transient diplopia, 2 (1.2%) had diabetes insipidus, and 1 (0.6%) had bone flap necrosis. We observed a dramatic decrease in mortality and morbidity in patients who underwent combined craniofacial resection after the first 30 cases in our series. Improvement of specific aspects of surgical technique, such as more refined reconstructive methods and improved prophylactic antibiotic therapy, is at least partly responsible for this favorable trend.
    Neurosurgery 01/2001; 47(6):1296-304; discussion 1304-5. · 2.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To determine the frequency and severity of neuropsychological impairments associated with aneurysmal subarachnoid haemorrhage, and associated with repair of intracerebral aneurysms. Two groups of patients who underwent repair of intracerebral aneurysms were studied: patients with unruptured aneurysms (n=20) and patients with ruptured aneurysms (n=27). All patients were administered a battery of standardised neuropsychological tests about 3 months after surgery. A subset of 12 patients with unruptured aneurysms were administered the battery both before and after elective repair of the aneurysm(s). A subset of six patients with ruptured aneurysms were given the test at both 3 months and 1 year after surgery. As previously reported for patients with ruptured aneurysms, patients with both ruptured and unruptured aneurysms performed, as a group, significantly below published norms on many of the neuropsychological tests after surgery. However, there were significant differences between preoperative and postoperative performance in the unruptured aneurysm group only on a few tests: measures of word fluency, verbal recall, and frontal lobe function. Performance of patients with ruptured aneurysms was significantly below that of patients with unruptured aneurysms only on a few tests of verbal and visual memory. In addition, group differences compared with published norms reflected severely impaired performance by a minority of patients, rather than moderately impaired performance in a majority of patients. Although patients who undergo repair of ruptured aneurysms perform, as a group, below published norms on many neuropsychological tests, significant impairments are seen in a minority of patients. Some of the impairments are associated with subarachnoid haemorrhage, whereas others (found in patients who underwent repair of unruptured aneurysms) are due to general effects of neurosurgery and perioperative management. Finally, some of the postoperative deficits are merely a reflection of premorbid weaknesses.
    Journal of Neurology Neurosurgery & Psychiatry 12/2000; 69(5):608-15. · 4.92 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Local delivery of carmustine (BCNU) via biodegradable polymers prolongs survival against experimental brain tumors and in human clinical trials. O6-benzylguanine (O6-BG), a potent inhibitor of the DNA repair protein, O6-alkylguanine-DNA alkyltransferase (AGT), has been shown to reduce nitrosourea resistance and, thus, enhance the efficacy of systemic BCNU therapy in a variety of tumor models. In this report, we demonstrate that O6-BG can potentiate the activity of BCNU delivered intracranially via polymers in rats challenged with a lethal brain tumor. Fischer 344 rats received a lethal intracranial challenge of 100,000 F98 glioma cells (F98 cells have significant AGT activity, 328 fmol/mg protein). Five days later, animals receiving an i.p. injection of O6-BG (50 mg/kg) 2 h prior to BCNU polymer (3.8% BCNU by weight) implantation had significantly improved survival (n = 7; median survival, 34 days) over animals receiving either O6-BG alone (n = 7; median survival, 22 days; P = 0.0002) or BCNU polymer alone (n = 8; median survival, 25 days; P = 0.0001). Median survival for the control group (n = 8) was 23.5 days. Moreover, there was no physical, behavioral, or pathological evidence of treatment-related toxicity. These findings suggest that O6-BG can potentiate the effects of interstitially delivered BCNU and, for tumors expressing significant AGT, may be necessary for the BCNU to provide a meaningful therapeutic benefit. Given the clinical use of BCNU polymers against malignant gliomas, concurrent treatment with O6-BG may provide an important addition to our therapeutic armamentarium.
    Cancer Research 12/2000; 60(22):6307-10. · 8.65 Impact Factor
  • American Journal of Ophthalmology 12/2000; 130(5):689. · 4.02 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To determine the long-term visual outcome in patients with parasellar and cavernous sinus meningiomas treated with nonradical surgery. Retrospective clinical review of 29 patients with parasellar or cavernous sinus meningiomas and visual sensory or ocular motor dysfunction at presentation, all of whom had at least 10 years of follow-up after initial diagnosis and treatment with nonradical surgery. Nineteen of 29 patients had a unilateral or bilateral optic neuropathy at presentation, and 7 patients developed a unilateral or bilateral optic neuropathy during a mean follow-up period of 13.6 years. However, 27 (93%) of 29 patients retained vision of 20/40 or better in at least one eye, and 14 patients (48%) retained vision of 20/40 or better in both eyes. New ocular motility deficits developed in 3 (10%) of 29 patients during the follow-up period. Radical surgery is not required to achieve long-term useful visual function for patients with parasellar or cavernous sinus meningiomas.
    Neurosurgery 08/2000; 47(1):24-31; discussion 31-2. · 2.53 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This Cervical Spine Research Society (CSRS) Study is a prospective, multicenter, nonrandomized investigation of patients with cervical spondylosis and disc disease. In this analysis, only patients with cervical myelopathy as the predominant syndrome were considered. To determine demographics, surgeon treatment practices, and outcomes in patients with symptomatic myelopathy. Current data on patient demographics and treatment practices of surgeons do not exist. There are no published prospective studies in which neurologic, functional, pain, and activities of daily living outcomes are systematically quantified. Patients were recruited by participating CSRS surgeons. Demographic information, patients' symptoms, and patients' functional data were compiled from patient and physician surveys completed at the time of initial examination, and outcomes were assessed from patient surveys completed after treatment. Data were compiled and statistically analyzed by a blinded third party. Sixty-two (12%) of the 503 patients enrolled by 41 CSRS surgeons had myelopathy. Patients (48.4% male; mean age, 48.7 +/- 12.03 years) had a mean duration of symptoms of 29.8 months (range, 8 weeks to 180 months). Surgery was recommended for 31 (50%) of these patients. Forty-three patients (69%) returned for follow-up and completed the questionnaire adequately for analysis. Twenty (46%) of the 43 patients on whom follow-up data are available underwent surgery, and 23 (54%) received medical treatment. Surgically treated patients had a significant improvement in functional status and overall pain, with improvement also observed in neurologic symptoms. Patients treated nonsurgically had a significant worsening of their ability to perform activities of daily living, with worsening of neurologic symptoms. When medical and surgical treatments are compared, surgically treated patients appear to have better outcomes, despite exhibiting a greater number of neurologic and nonneurologic symptoms and having greater functional disability before treatment. Randomized studies, if feasible, should be performed to address outcome in cervical myelopathy further.
    Spine 04/2000; 25(6):670-6. · 2.16 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Local delivery of cytokines has been shown to have a potent antitumor activity against a wide range of malignant brain tumors. In this study, the authors examined the efficacy of treating central nervous system (CNS) tumors by transfecting poorly immunogenic B16/F10 melanoma cells with interleukin (IL)-2, IL-4, or granulocytemacrophage-colony stimulating factor (GM-CSF) gene, and using these cells to deliver the cytokine locally at the site of the CNS tumor. The object was to determine which cytokine would possess the greatest antitumor activity and to further elucidate its mechanism of action. The transfected B16/F10 cells were irradiated to prevent replication and injected intracranially into C57BL/6 mice (10 mice per group) along with nonirradiated, nontransfected B16/F10 (wild-type) melanoma cells. Sixty percent of mice treated with IL-2 (p < 0.001 compared with control) and 10% treated with IL-4 (median survival = 31 days, p < 0.001 compared with control) were long term survivors (> 120 days). The median survival for animals treated with GM-CSF was 22 days with no long term survivors (p = 0.01 compared with control). Control animals that received only wild-type cells had a median survival of 18 days (range 15-20 days). Histopathological examination of brains from animals killed at different times showed minimal infiltration of tumor cells in the IL-2 group, moderate infiltration of tumor cells in the IL-4 group, and gross tumor invasion and tissue necrosis in the GM-CSF group. Animals treated with IL-2 showed a strong CD8 T cell-mediated response, whereas IL-4 evoked a prominent eosinophilic infiltrate in the area of the tumor. High levels of locally expressed IL-2 rather than IL-4 or GM-CSF stimulate a strong immunological cytotoxic antitumor response that leads to significant prolongation of survival in mice challenged with B16/F10 intracranial melanoma tumor cells. Consequently, IL-2 may be a superior candidate for use in paracrine immunotherapy.
    Neurosurgical FOCUS 02/2000; 9(6):e4. · 2.49 Impact Factor
  • P Sampath, D M Long, H Brem
    [Show abstract] [Hide abstract]
    ABSTRACT: Modern neurosurgery has long had a strong laboratory foundation, and much of this tradition can be traced to the Hunterian Neurosurgical Laboratory of the Johns Hopkins Hospital. Founded with the basic goals of investigating the causes and symptoms of disease and establishing the crucial role that surgeons may play in the treatment of disease, the Hunterian laboratory has adhered to these tenets, despite the dramatic changes in neurosurgery that have occurred in the last 100 years. Named for the famous English surgeon John Hunter (1728-1793), the Hunterian laboratory was conceived by William Welch and William Halsted as a special laboratory for experimental work in surgery and pathology. In 1904, Harvey Cushing was appointed by Halsted to direct the laboratory. With the three primary goals of student education, veterinary surgery that stressed surgical techniques, and meticulous surgical and laboratory record-keeping, the laboratory was quite productive, introducing the use of physiological saline solutions, describing the anatomic features and function of the pituitary gland, and establishing the field of endocrinology. In addition, the original development of hanging drop tissue culture, fundamental investigations into cerebrospinal fluid, and countless contributions to otolaryngology by Samuel Crowe all occurred during this "crucible" period. In 1912, Cushing was succeeded by Walter Dandy, whose work on experimental hydrocephalus and cerebrospinal fluid circulation led to the development of pneumoencephalography. The early days of neurosurgery evolved with close ties to general surgery, and so did the Hunterian laboratory. After Dandy began devoting his time to clinical work, general surgeons (first Jay McLean and then, in 1922, Ferdinand Lee) became the directors of the laboratory. Between 1928 and 1942, more than 150 original articles were issued from the Hunterian laboratory; these articles described significant advances in surgery, including pioneering research on calcium metabolism by William MacCallum and Carl Voegtlin and seminal preclinical work by Alfred Blalock and Vivian Thomas that led to the famous "blue baby" operation in 1944. With the introduction of the operating microscope in the 1950s, much of the focus in neurosurgical science shifted from the laboratory to the operating room. The old Hunterian building was demolished in 1956. The Hunterian laboratory for surgical and pathological research was rebuilt on its original site in 1987, and the Hunterian Neurosurgical Laboratory was reestablished in 1991, with a focus on novel treatments for brain tumors. The strong tradition of performing basic research with clinical relevance has continued.
    Neurosurgery 02/2000; 46(1):184-94; discussion 194-5. · 2.53 Impact Factor
  • P Sampath, D Rini, D M Long
    [Show abstract] [Hide abstract]
    ABSTRACT: Great advances in neuroimaging, intraoperative cranial nerve monitoring, and microsurgical technique have shifted the focus of acoustic neuroma surgery from prolonging life to preserving cranial nerve function in patients. An appreciation of the vascular and cranial nerve microanatomy and the intimate relationship between neurovascular structures and the tumor is essential to achieve optimum results. In this paper the authors analyze the microanatomical variations in location of the facial and cochlear nerves in the cerebellopontine angle (CPA) associated with acoustic neuromas and, additionally, describe the frequency of involvement of surrounding neural and vascular structures with acoustic tumors of varying size. The authors base these findings on their experience with 1006 consecutive patients who underwent surgery via a retrosigmoid or translabyrinthine approach. Between July 1969 and January 1998, the senior author (D.M.L.) performed surgery in 1022 patients for acoustic neuroma: 705 (69%) via the retrosigmoid (suboccipital); 301 (29%) via the translabyrinthine; and 16 (2%) via the middle fossa approach. Patients undergoing the middle fossa approach were excluded from the study. The remaining 1006 patients were subdivided into three groups based on tumor size: Group I tumors (609 patients [61%]) were smaller than 2.5 cm; Group II tumors (244 patients [24%]) were between 2.5 and 4 cm; and Group III tumors (153 patients [15%]) were larger than 4 cm. The senior author's operative notes were analyzed for each patient. Relevant cranial nerve and vascular "involvement" as well as anatomical location with respect to the tumor in the CPA were noted. "Involvement" was defined as adherence between neurovascular structure and tumor (or capsule), for which surgical dissection was required to free the structure. Seventh and eighth cranial nerve involvement was divided into anterior, posterior, and polar (around the upper or lower pole) locations. Anterior and posterior locations were further subdivided into upper, middle, or lower thirds of the tumor. The most common location of the seventh cranial nerve (facial) was the anterior middle third of the tumor for all groups, although a significant number were found on the anterior superior portion. The posterior location was exceedingly rare (< 1%). Interestingly, patients with smaller tumors (Group I) had an incidence (3.4%) of the seventh cranial nerve passing through the tumor itself, equal to that of patients with larger tumors. The most common location of the eighth cranial nerve complex was the anterior inferior portion of the tumor. Not surprisingly, larger tumors (Group III) had a higher incidence of involvement of fourth cranial nerve (41%), fifth cranial nerve (100%), ninth-11th cranial nerve complex (99%), and 12th cranial nerve (31%), as well as superior cerebellar artery (79%), anterior inferior cerebellar artery (AICA) trunk (91.5%), AICA branches (100%), posterior inferior cerebellar artery (PICA) trunk (59.5%), PICA branches (79%), and the vertebral artery (VA) (93.5%). A small number of patients in Group III also had AICA (3.3%), PICA (3.3%), or VA (1.3%) vessels within the tumor itself. In this study, the authors show the great variation in anatomical location and involvement of neurovascular structures in the CPA. With this knowledge, they present certain technical lessons that may be useful in preserving nerve function during surgery and, in doing so, hope to provide neurosurgeons and neurootologists with valuable information that may help to achieve optimum outcomes in patients.
    Journal of Neurosurgery 01/2000; 92(1):70-8. · 3.15 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Despite advances in neuroimaging and neurosurgical treatment, spinal epidural abscess remains a challenging problem; early diagnosis is often difficult and treatment is delayed. Optimal management is unclear, and morbidity and mortality are significant. To define contemporary trends in etiology and management, and establish diagnostic and therapeutic guidelines, we reviewed our 10-year experience with spinal epidural abscess. We examined medical records, laboratory data, radiological (CT and MRI) studies, and operative reports from 75 cases of spinal epidural abscess between 1983 and 1992. Demographic characteristics, frequency, clinical features, pathogens, risk factors, surgical and medical treatment, and outcome were analyzed. We found a significant increase in the frequency of spinal epidural abscess over the 10-year period (p-value = 0.0195). Intravenous drug abuse was present in 28 patients (33%), diabetes mellitus in 22 patients (27%), and prior spinal surgery in 11 patients (17%). Back pain, progressive neurologic deficit, and low grade fever remained the distinguishing diagnostic features. Erythrocyte sedimentation rate was elevated in 48 of 50 patients (95%); peripheral leukocyte count was elevated in 45 patients (60%). MRI was the most effective technique for diagnosing spinal epidural abscess, revealing or suggesting the diagnosis in all 59 patients (100%) studied. Sites of spinal epidural abscess were equally distributed along the spinal axis. Staphylococcus aureus was the predominant organism (67% of patients, with 15% having a methicillin-resistant strain); 8% of patients had Streptococcal species. Most patients had open surgical drainage followed by prolonged antibiotic treatment; 22 patients were managed with antibiotics alone; 50 patients (66%) had a good clinical outcome after treatment. Multiple medical problems, prior spinal surgery, and methicillin-resistant Staphylococci were correlated with a significantly worse outcome. The frequency of diagnosis of spinal epidural abscess is increasing. To prevent serious morbidity and mortality, early diagnosis is essential. Patients with localized back pain who are at risk for developing such abscesses or who have an increased erythrocyte sedimentation rate and/or neurologic deficit should have an immediate MRI scan with contrast enhancement. Surgical drainage and prolonged antibiotic use are the cornerstones of treatment, although selected patients may be treated conservatively.
    Surgical Neurology 09/1999; 52(2):189-96; discussion 197. · 1.67 Impact Factor
  • C Guerin, P Sampath, D M Long
    [Show abstract] [Hide abstract]
    ABSTRACT: The treatment of acoustic neuroma (vestibular schwannoma) has evolved greatly. In this report, we studied the history of acoustic tumour surgery, and documented the value of technical advances in benefiting patients. We also present our outcome of surgery for this benign tumour in support of its use as the treatment of choice. In 611 patients undergoing initial surgery at Johns Hopkins from 1973-1994, complete resection was obtained in all but one case (intentional), and permanent morbidity and mortality rate was 0.3%. Including temporary morbidity, the rate was 3.8%. Tumour recurrence was seen in only 0.8% of cases. The facial nerve was preserved in 97.6% and function at one-year was House-Brackmann grade 1 or 2 in 89.7%. Lastly, we present results of an anatomical study localizing the nerves and vessels, and the frequency of involvement by tumour, associated with acoustic neuromas in 1006 surgical cases. We continue to offer surgery as the best treatment option for the majority of our patients, and prefer the suboccipital route because of its unrestricted access to all posterior fossa structures, and ability to preserve hearing.
    Annals of the Academy of Medicine, Singapore 06/1999; 28(3):402-8. · 1.36 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Potent immune responses against malignant brain tumors can be elicited by paracrine intracranial (i.c.) immunotherapy with interleukin (IL)-2. Additionally, i.c. delivery of carmustine via biodegradable polymers has been shown to significantly prolong survival in both animal models and clinical trials. In this study, we show that the combination of paracrine immunotherapy, with nonreplicating genetically engineered tumor cells that produce IL-2, and local delivery of chemotherapy by biodegradable polymers prolongs survival in a synergistic manner in mice challenged intracranially with a lethal murine brain tumor. Animals receiving IL-2-transduced cells and polymers containing 10% 1,3-bis(2-chloroethyl)-1-nitrosourea had significantly improved survival compared with animals receiving IL-2-transduced cells or 10% 1,3-bis(2-chloroethyl)-1-nitrosourea alone. Median survival for the control group was 19 days. Survival in animals receiving IL-2-transduced cells and 1% carboplatin-containing polymers was also significantly improved compared with either therapy alone. Histopathological examination on day 14 of animals receiving combination treatment showed rare degenerating tumor cells. In addition to tissue necrosis surrounding the polymer, a marked inflammatory reaction was observed. In long-term survivors (all animals receiving combination treatment), no tumor was observed and the inflammatory reaction was completely resolved. The brains of animals receiving combination therapy showed both tissue necrosis due to local chemotherapy and strong inflammation due to paracrine immunotherapy. The demonstration of synergy between paracrine IL-2 and local i.c. delivery of antineoplastic drugs is novel and may provide a combined treatment strategy for use against both primary and metastatic i.c. tumors.
    Cancer Research 06/1999; 59(9):2107-14. · 8.65 Impact Factor
  • P Sampath, D Rigamonti
    [Show abstract] [Hide abstract]
    ABSTRACT: Despite advances in neuroimaging and neurosurgical treatment, spinal epidural abscess (SEA) remains a challenging problem for the practicing physician. Early diagnosis is often elusive, and treatment is delayed. The optimal management of SEA is not clearly defined, and morbidity and mortality remain significant. In this review article, we discuss contemporary issues surrounding SEA. In addition, we shed light on the epidemiology of this potentially devastating disease and outline current diagnostic and therapeutic guidelines. We find the frequency of diagnosis of SEA is increasing. To prevent serious morbidity and mortality, early diagnosis and prompt treatment are essential. Patients who are at high risk for developing such abscesses should have an immediate magnetic resonance scan with contrast enhancement. Surgical drainage and prolonged antibiotic use are the cornerstones of treatment, although selected patients may be treated nonsurgically with very vigilant medical follow-up.
    Journal of Spinal Disorders 05/1999; 12(2):89-93. · 1.21 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The Cervical Spine Research Society study is a prospective, nonrandomized, multicenter investigation of patients with cervical spondylosis and disc disease. In this analysis, only patients who had radiculopathy without myelopathy as the predominant symptom were considered. To determine demographics, surgeon treatment practices, and outcomes in patients with symptomatic radiculopathy. Current data on patient demographics and treatment practices of surgeons do not exist. There are no published prospective studies in which outcomes, including pain, function, neurologic symptoms, and ability to perform activities of daily living, are systematically quantified. Patients were recruited by participating Cervical Spine Research Society surgeons. Demographic, symptomologic, and functional patient data were compiled from surveys of patients and physicians completed at the time of initial examination, and outcomes were assessed from surveys of patients completed after treatment. Data were compiled and statistically analyzed by a blinded third party. Of the 503 patients enrolled by 41 CSRS surgeons, 246 (49%) had radiculopathy. Patients had a mean duration of symptoms of 26.7 months (range, 8 weeks to > 352 months) and a mean age of 48.1 +/- 12.42 years; 44.7% were female. Surgery was recommended for 86 (35%) of these patients. Of the 155 patients on whom there were follow-up data, 51 (33%) underwent surgery, whereas 104 (67%) received medical treatment. Surgically treated patients had a significant improvement in pain, neurologic symptoms, functional status, and ability to perform activities of daily living. A significant number of patients who underwent surgery reported persistent excruciating or horrible pain on follow-up (26%). Patients treated medically also had significant improvement in pain and overall functional status. In summary, this study represents the first in-depth, prospective outcome analysis of patients with cervical spondylotic and discogenic radiculopathy.
    Spine 04/1999; 24(6):591-7. · 2.16 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Despite improved systemic control of metastatic breast cancer, the incidence of brain metastases from breast carcinoma continues to rise, in part because most systemically administered agents have poor central nervous system penetration. Therefore, as a method of optimizing drug delivery into the central nervous system, we studied the safety and efficacy of chemotherapy delivered locally via biodegradable polymers in a mouse model of breast carcinoma metastases to the brain. The chemotherapeutic agents carmustine (BCNU), carboplatin, and camptothecin were incorporated into controlled release polymers and tested individually against intracranial challenges of EMT-6 breast tumor in BALB/c female mice. For each drug, four groups were tested: Group 1, empty polymer (no drug); Group 2, external beam radiotherapy (XRT) alone; Group 3, local chemotherapy from biodegradable polymer alone; and Group 4, local chemotherapy and XRT together. Polymers were implanted 5 days after intracranial tumor inoculation; XRT was administered on Days 7 through 9 (300 cGy/d). BCNU polymer alone (n = 10; median survival time, >200 d; P < 0.0001) and BCNU and XRT together (n = 10; median survival time, 41 d; P = 0.02) significantly improved survival in mice with intracranial EMT-6 breast cancer in comparison with control animals (n = 20; median survival time, 17 d). Carboplatin and camptothecin, either with or without XRT, and XRT alone did not have any significant effect on survival. Local delivery of BCNU with biodegradable polymers can significantly prolong survival in a murine model of intracranial metastatic breast cancer. Surgical resection and placement of BCNU polymers into the resection cavity may decrease the incidence of local recurrence of breast cancer metastases with minimal morbidity.
    Neurosurgery 11/1998; 43(5):1185-93. · 2.53 Impact Factor
  • D Chou, P Sampath, H Brem
    [Show abstract] [Hide abstract]
    ABSTRACT: Hemorrhagic vestibular schwannomas are rare entities, with only a few case reports in the literature during the last 25 years. The authors review the literature on vestibular schwannoma hemorrhage and the presenting symptoms of this entity, which include headache, nausea, vomiting, sudden cranial nerve dysfunction, and ataxia. A very unusual case is presented of a 36-year-old man, who unlike most of the patients reported in the literature, had clinically silent vestibular schwannoma hemorrhage. The authors also discuss the management issues involved in more than 1000 vestibular schwannomas treated at their institution during a 25-year period.
    Neurosurgical FOCUS 10/1998; 5(3):e9. · 2.49 Impact Factor
  • M J Holliday, P Sampath
    [Show abstract] [Hide abstract]
    ABSTRACT: Delayed facial nerve palsy, a condition characterized by spontaneous deterioration of facial nerve function in patients who had otherwise normal or near-normal facial function in the immediate postoperative period, has been reported in 15 to 29% of patients undergoing microsurgical resection of vestibular schwannomas. One putative mechanism for its occurrence suggests that edematous entrapment of the facial nerve in the meatal foramen (the narrowest segment of the internal auditory canal) may lead to nerve ischemia or necrosis and subsequent facial nerve dysfunction. To assess whether meatal decompression may help reduce the incidence of delayed facial nerve palsy during microsurgical resection of acoustic tumors, we compared 25 patients undergoing translabyrinthine removal of acoustic neuromas who received prophylactic decompression of the labyrinthine segment of the facial nerve (Group 1) with 40 patients who did not receive facial nerve decompression (Group 2). No patients in Group 1 had a delayed progressive facial paralysis with degeneration. In contrast, when Group 2 patients with larger, average-sized tumors were reviewed, eight patients (20%) developed delayed degeneration. These findings suggest that decompression of the labyrinthine segment may be of value in acoustic tumor surgery in reducing delayed facial nerve dysfunction. Further study is indicated in this important area.
    Neurosurgical FOCUS 10/1998; 5(3):e7. · 2.49 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Delayed facial nerve dysfunction after vestibular schwannoma surgery is a poorly understood phenomenon that has been reported to occur in 15 to 29% of patients undergoing microsurgery. It is a condition characterized by spontaneous deterioration of facial nerve function in a patient who has otherwise normal or near-normal facial function in the immediate postoperative period. This delayed paralysis is generally reported to occur in the first few days postsurgery, with the majority of patients eventually recovering their immediate postoperative facial function. However, infrequently, it can also occur more than 1 week after surgery (so-called late-onset facial nerve palsy). The authors reviewed facial nerve outcome in 611 patients who underwent microsurgery between 1973 and 1994. The facial nerve was anatomically preserved in 596 patients (97.5%), and 90% of patients had House-Brackmann[6] Grade 1 or 2 function 1 year after surgery. Late-onset facial dysfunction was seen in 13 patients (2.1%). All of these had significant deterioration in facial nerve function between 1 and 4 weeks postoperatively, and all showed improvement by 1 year. In this study, the focus on these patients who developed late-onset facial palsy. The incidence, treatment strategies, and outcomes will be discussed with emphasis on possible pathophysiological mechanisms that contribute to this relatively rare condition.
    Neurosurgical FOCUS 10/1998; 5(3):e6. · 2.49 Impact Factor
  • P Sampath, H Brem
    [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Despite significant advances in neurosurgery, radiation therapy, and chemotherapy, the prognosis for patients with malignant brain tumors remains dismal. In an effort to improve control of local disease, we have developed a biodegradable, controlled-release polymer that is implanted directly at the tumor site. METHODS: The preclinical and clinical development of the polymeric delivery of chemotherapeutic agents for treatment of patients with malignant gliomas is reviewed. RESULTS: Carmustine (BCNU)-impregnated biodegradable polymer is the first new therapy approved by the FDA for patients with gliomas in 23 years. This delivery system provides high local concentration of drug with minimal systemic toxicity and obviates the need for drug to cross the blood-brain barrier. Randomized, multi-institutional, double-blinded, placebo-controlled studies have shown improved survival in patients treated for gliomas both at initial presentation and at recurrence. Several clinical principles have emerged from the use of this polymer system, and further applications are currently being investigated. CONCLUSIONS: Local delivery of therapeutic agents via biodegradable polymers may play an increasing role in patients with brain tumors.
    Cancer control: journal of the Moffitt Cancer Center 04/1998; 5(2):130-137. · 3.59 Impact Factor
  • Prakash Sampath, David Rini, Donlin M. Long
    Neurosurgical Focus - NEUROSURG FOCUS. 01/1998; 5(3).

Publication Stats

684 Citations
69.83 Total Impact Points

Institutions

  • 1997–2000
    • Johns Hopkins Medicine
      • • Department of Neurosurgery
      • • Division of General Surgery and Surgical Oncology
      Baltimore, MD, United States
  • 1999
    • Johns Hopkins University
      • Department of Neurosurgery
      Baltimore, MD, United States
  • 1998
    • University of North Carolina at Chapel Hill
      North Carolina, United States