Showing papers by "Patrick J. Kelly published in 1993"

Resection, biopsy, and survival in malignant glial neoplasms. A retrospective study of clinical parameters, therapy, and outcome.

Abstract: ✓ Between July, 1984, and October, 1988, 263 patients (163 male, 100 female), aged from 4 to 83 years (mean 52 years), with malignant brain gliomas underwent surgical procedures: stereotactic biopsy in 160 and resection in 103 patients. There were 170 grade IV astrocytomas, 17 grade IV mixed oligoastrocytomas, 44 grade III astrocytomas, 22 grade III mixed oligoastrocytomas, and 10 malignant oligodendrogliomas. Overall median survival time was 30.1 weeks for grade IV gliomas, 87.7 weeks for grade III gliomas, and 171.3 weeks for malignant oligodendrogliomas. Multivariate analysis in 218 newly diagnosed cases revealed that the variables most strongly correlated with survival time were: tumor grade, patient age, seizures as a first symptom, a Karnofsky Performance Scale score of less than 70%, tumor resection, and a radiation therapy dose greater than 50 Gy. The proportions of patients receiving tumor resection versus biopsy in each of these prognosis factor groups were similar. Since most of the 22 patients...

MRI hippocampal volumes and memory function before and after temporal lobectomy

Abstract: We investigated the relationship between preoperative MRI hippocampal volumes and clinical neuropsychological memory test data obtained before and after temporal lobectomy and amygdalohippocampectomy for intractable epilepsy in 44 left (LTL) and 36 right (RTL) temporal lobectomy patients. In LTL patients, the difference (right minus left hippocampal volume) between hippocampal volumes (DHF) was significantly ( p r = 0.61) with postoperative verbal memory change as measured by a delayed memory percent retention score from the Wechsler Memory Scale-Revised, Logical Memory subtest. DHF was also positively associated with postoperative memory for abstract geometric designs in LTL patients ( r = 0.49, p

Gelastic seizures and hypothalamic hamartomas Evaluation of patients undergoing chronic intracranial EEG monitoring and outcome of surgical treatment

Abstract: We retrospectively studied 12 consecutive patients with gelastic seizures and hypothalamic hamartomas who, because of intractable epilepsy, underwent chronic intracranial EEG monitoring or epilepsy surgery. All patients had medically refractory seizures that included laughter as an ictal behavior (gelastic seizures). The hypothalamic hamartomas were identified with neuroimaging studies (12 of 12) and by pathologic verification (four of 12). Associated clinical features included behavioral disorders (n = 5), developmental delay (n = 4), and precocious puberty (n = 2). Interictal extracranial EEG predominantly showed bi-hemispheric epileptiform changes suggesting a secondary generalized epileptic disorder. Intracranial EEG recordings, performed in eight patients, indicated the apparent focal onset of seizure activity (anterior temporal lobe [n = 7] and frontal lobe [n = 1]). None of the seven patients who underwent a focal cortical resection, however, experienced a significant reduction in seizure tendency. An anterior corpus callosotomy, performed in two patients with symptomatic generalized epilepsy, resulted in a worthwhile reduction in drop attacks. Results of this study may modify the surgical strategies in patients with gelastic seizures and hypothalamic hamartomas.

Surgical Treatment for Epilepsy in Cerebral Tuberous Sclerosis

Abstract: Tuberous sclerosis (TS) is an autosomal dominant hamartiosis and hamartomatosis with variable expression that is commonly associated with medically intractable seizures. Patients with TS complex (TSC) frequently have multiple brain lesions that can give rise to seizure activity. We report 9 patients with TSC who underwent epilepsy surgery at the Mayo Clinic between 1986 and 1990. Surgical procedures performed included cortical resection (n = 2) and stereotaxic lesionectomy (n = 7). Neuropathologic diagnoses were cortical tubers (n = 7) and glioneural hamartomas (n = 2). Three of 9 patients had multifocal interictal scalp epileptiform EEG activity; however, ictal recordings identified the focus of seizure activity, which in all cases corresponded to a prominent neuroimaging abnormality. Our patients have been followed for 10-72 months (mean 35 months). Four patients are seizure-free with medication, 2 are seizure-free without medication, 2 had > 80% reduction in seizure frequency, and 1 experienced only an initial temporary reduction in seizure frequency. Postoperative EEG recordings showed absence of epileptiform abnormalities in the 5 patients who are seizure-free; the other 4 patients continue to have multifocal abnormalities. These data suggest that epilepsy surgery may be beneficial in selected patients with TSC despite multifocal EEG and neuroimaging abnormalities.

Oligodendrocyte Injury Is an Early Event in Lesions of Multiple Sclerosis

Abstract: The ultrastructural features of 11 stereotaxic brain biopsy specimens that demonstrated inflammatory primary demyelination consistent with acute multiple sclerosis were examined Uniform widening of inner myelin lamellae (biphasic myelinopathy) and degeneration of inner glial loops ("dying-back" oligodendrogliopathy) were early pathologic abnormalities that antedated complete destruction of myelin sheaths Perivascular inflammatory cells (lymphocytes, macrophages, and occasional plasma cells) were in intimate contact with degenerating myelin sheaths The response of astrocytes was prominent, even in areas of minimal demyelination Oligodendrocytes were morphologically preserved in early lesions but proliferated at the periphery of active lesions Thinly myelinated axons indicative of central nervous system-type remyelination by oligodendrocytes were observed primarily at the edge of plaques Disturbances of the myelinating function of oligodendrocytes—unaccompanied by death of these cells—may be among the earliest pathologic features in multiple sclerosis

Intracranial parenchymal schwannoma. A clinicopathological and neuroimaging study of nine cases.

Abstract: The clinical, radiological, and pathological features of nine cases of intracranial parenchymal schwannoma are described. The clinical course in four patients 23 years of age or younger mirrored the indolent nature of this neoplasm. Imaging studies included computerized tomography in eight patients and magnetic resonance imaging in three. The lesions were well demarcated with only mild surrounding edema. Five tumors were deep within the temporoparieto-occipital region, three were in the cerebellum, and one lay peripherally in the parietal lobe. Over two-thirds of the nine tumors were either cystic (five) or contained areas of cystic degeneration (two). One lesion was frankly hemorrhagic. A variety of imaging characteristics and contrast enhancement patterns were observed, including those of a cyst with a mural nodule and peripheral enhancement. Of the four solid neoplasms, two enhanced homogeneously while the other two demonstrated heterogeneous enhancement. Six tumors were resected totally. The follow-up period ranging from 2 months to 2 years has shown no recurrences. Microscopically, immunohistochemically, and ultrastructurally, the tumors were indistinguishable from peripheral schwannomas. A possible mechanism underlying the histogenesis of these rare lesions is discussed. The importance of recognizing this tumor is stressed, particularly in younger patients, given its benign nature, radiological resemblance to other tumors such as pilocytic astrocytoma, and favorable response to resection.

Resection of intraventricular tumors via a computer-assisted volumetric stereotactic approach.

Abstract: Intraventricular tumors present a major challenge for neurosurgeons because of their depth and the important structures around them. Between 1984 and 1991, we performed 60 computer-assisted volumetric stereotactic resection procedures in 58 patients with intraventricular tumors (30 patients with third ventricular tumors and 28 patients with lateral ventricular tumors). The pathological findings of the tumors were as follows: colloid cyst in 27, giant cell astrocytoma in 5, central neurocytoma in 4, pilocytic astrocytoma in 4, meningioma in 3, subependymoma in 3, metastatic tumor in 3, oligodendroglioma in 2, ependymoma in 2, and miscellaneous tumors in 5 patients. Most presenting symptoms were nonlocalized--headache or cognitive dysfunction. All third ventricular tumors were approached via a frontal trajectory, and lateral ventricular tumors were approached according to the site and shape of the lesion. Total resection was achieved in 55 procedures. Overall outcome was excellent in 45 cases, good (some deficit but independent) in 5, and poor (dependent) in 3 (memory impairment, 2 patients; visual field cut, 1 patient). Two patients (3.4%) died postoperatively (one had a postoperative thalamic hemorrhage and pulmonary embolus; one had a subdural hygroma). In follow-up, three patients died from the extension of a malignant tumor or from primary cancer. Permanent morbidity was seen in three cases (5%). The authors believe computer-assisted volumetric stereotaxis is useful in removing intraventricular tumors. This technique allows us to find a safe trajectory and to locate and separate the tumor margin from the surrounding vital structures.

Parietal Lobe Lesional Epilepsy: Electroclinical Correlation and Operative Outcome

Abstract: We retrospectively studied ictal behavior, extracranial EEG, and operative outcome in 10 consecutive patients with intractable partial epilepsy of presumed parietal lobe origin who received a lesionectomy, i.e., resection of the neuroimaging-identified abnormality, at the Mayo Clinic. Nine patients had a pathologically verified foreign-tissue lesion, e.g., tumor or vascular malformation, and 1 patient had gliosis. All patients with foreign-tissue lesions were rendered seizure-free. The patient with gliosis experienced a reduction in seizure tendency. There were no operative complications. The most common seizure type was a simple partial seizure with visual, motor, or sensory symptoms (n = 8). Complex partial seizures (n = 5) and secondarily generalized tonic-clonic seizures (GTC, n = 2) were also observed. The ictal behavior was often nonspecific although useful in identifying lateralization of the epileptogenic zone. Extracranial interictal and ictal EEG changes were unreliable markers of the parietal lobe origin of seizure activity. Lesionectomy without chronic intracranial monitoring or functional mapping may be an effective and safe alternative surgical procedure in patients with partial epilepsy related to parietal lobe lesions.

Stereotactic Procedures for Lesions of the Pineal Region

Abstract: During the 7-year period between June 1985 and May 1992, 34 patients with pineal lesions underwent 66 stereotactic procedures (37 biopsies, 19 third ventriculostomies, 6 cyst aspirations, 3 instillations of 32P into cysts, and 1 insertion of an Ommaya reservoir into a cyst) at the Mayo Clinic. Nine patients subsequently also underwent 10 open resections of lesions of the pineal region. In the 34 study patients, the pathologic entities were 9 gliomas (5 astrocytomas, 2 ependymomas, and 2 oligodendrogliomas), 9 germ cell tumors (7 germinomas, 1 entodermal sinus tumor, and 1 malignant teratoma), 8 pineal parenchymal tumors (3 pinealomas, 3 pinealoblastomas, 1 mixed pinealoma-pinealoblastoma, and 1 intermediate differentiation pineal tumor), 4 other malignant tumors (2 undifferentiated carcinomas, 1 malignant melanoma, and 1 non-Hodgkin's lymphoma), 2 meningiomas, and 2 nonneoplastic lesions (1 glial cyst and 1 inflammatory lesion). No mortality or permanent morbidity was associated with the 66 stereotactic procedures; 2 patients had temporary complications—1 neurologic (transient diplopia) and 1 nonneurologic (pulmonary embolism). Diagnostic tissue was obtained in 33 of the 34 patients. An algorithm for the diagnosis and management of patients with lesions of the pineal region is presented. We conclude that stereotactic biopsy of pineal lesions can be performed safely, has a high diagnostic yield, and facilitates rational planning of treatment.

MRI assessments of hippocampal pathology in extratemporal lesional epilepsy

Abstract: We performed a prospective study in 18 patients to determine the extent of MRI-identified hippocampal pathology in patients with intractable partial epilepsy of extratemporal origin. A mesial temporal signal-intensity alteration or hippocampal formation (HF) atrophy, or both, have been shown to be reliable markers of the temporal lobe of seizure origin in patients with mesial temporal sclerosis. All patients subsequently received surgical ablative therapy between 1988 and 1992. During shortterm follow-up, 14 of the 18 patients experienced a significant reduction in seizure tendency, and 12 patients were rendered seizure-free. Qualitative and quantitative (HF volumetry) assessments of HF pathology were performed retrospectively by a blinded investigator. No hippocampal imaging alteration was present in 17 patients. Left HF atrophy was confirmed in one patient with post-traumatic epilepsy who underwent a successful right frontal lobectomy. Morphometric MRI studies rarely identify hippocampal pathology in patients with extratemporal epilepsy.

A new concept in fracture immobilization. The application of a pressurized brace.

Abstract: Sixteen dogs and 14 anatomic tibiae were studied to determine the effect of a pressurized brace on a canine tibial fracture model. Bilateral tibial fractures were treated with an external fixator for 48 days. At 48 days, the pressurized brace was applied to one tibia, and a conventional cast was applied to the opposite tibia. The dogs were allowed unrestricted weight bearing until 88 days. Postmortem biomechanical studies indicated that tibiae were stronger on the side treated by the pressurized brace. This was reflected in torque values, energy, and degrees of rotation. The histomorphometry of the periosteal bone of the fracture sites disclosed a more dense periosteal callus on the side treated with a pressurized brace. In vitro mechanical studies in cadaveric tibias at 30 degrees rotation indicated that the pressurized brace provided significantly more stability.

Changes in Proliferating Cell Nuclear Antigen Expression in Glioblastoma Multiforme Cells Along a Stereotactic Biopsy Trajectory

Abstract: Proliferating cell nuclear antigen, an auxiliary protein of deoxyribonucleic acid polymerase-delta, has been shown to be a reliable marker of nuclear deoxyribonucleic acid synthetic activity We applied a monoclonal antibody to proliferating cell nuclear antigen to a series of serial stereotactic biopsies from patients with glioblastoma multiforme and found the proliferative activity to vary relative to biopsy location within or surrounding the solid tissue component of the tumor Twenty-seven trajectories in 26 patients were analyzed, each consisting of two to five sequential 10 x 15 mm core biopsies (mean = 3) The proliferative index (PI) was greatest in those cells located at the solid tumor-infiltrated parenchyma interface PI values were significantly lower in those biopsy cores located proximal (within infiltrated parenchyma) and distal (within solid tumor tissue) to the solid tumor-infiltrated parenchyma interface (median PI values, proximal to distal: 038, 066, 545 solid tumor-infiltrated parenchyma interface], 039, 009%) The mean PI values were significantly lower in neoplastic cells samples from regions of peripheral hypodensity on computed tomographic scans compared with those sampled from contrast-enhancing regions (09 and 391%, respectively) There was no significant difference in the mean PI values of neoplastic cells sampled from regions of contrast enhancement or central hypodensity (391 and 431%, respectively)

Perturbations of Vascularization and Circulation Due to Osteosynthetic Methods

Abstract: It is axiomatic to say that an adequate blood supply is necessary for initiation of the healing response (Trueta, 1963). The fracture in itself will alter blood flow and flow will be changed if treated by osteosynthetic methods. The surgeon treating fractures finds tibial fractures the most worrisome for two reasons: the tibia is so commonly a site of infection following trauma (Kelly et al., 1990) and it is a frequent site of compartment syndrome (Blick, 1986). Fixation of fractures leads to changes in bone structure. This has been principly emphasized in the tibia and in response to plate fixation. It has been postulated that this change in bone mass is secondary to alterations of fracture stability by various forms of fixation. Stated more clearly, changes in stability lead to decreased formation of bone and to increased resorption of existing bone, perhaps by decreasing the feedback mechanism of strain related potentials that may control bone remodeling, or alternatively, it may decrease transcapillary fluid flow to osteoblasts which contain necessary substrates for cell nutrition (Kelly and Bronk, 1990). Studies have shown that plates interfere with cortical remodeling (Akeson et al., 1976; Jacobs et al., 1981; Uhtoff et al., 1983). Effects of fixation on fracture healing have been recently reviewed (O’Sullivan et al., 1989). While there have been studies on the effects of intramedullary fixation on diaphyseal bone circulation (Dankwardt, 1969), no studies have systematically examined the effect of the three common forms of fracture fixation, external fixation (EF), intramedullary rod (IMR), and plate (PL), on bone remodeling and blood flow in a single study.