Biomedical subjects
E Alexander
Publications and source records attributed to E Alexander.
Impalement of the head.
Explore the source record for details and available documents.
Extracranial metastatic glioblastoma: appearance on thallium-201-chloride/technetium-99m-HMPAO SPECT images.
Sequential thallium-201-chloride and technetium-99m-hexamethylpropyleneamine oxime single-photon emission computed tomography (SPECT) images were obtained in a patient with extracranial metastatic glioblastoma multiforme. Thallium-201 uptake was high (three times the scalp background) in all pathologically confirmed extracranial metastases and moderate (1.6 times scalp background) intracranially, where most biopsy specimens showed gliosis with scattered atypical astrocytes. Technetium-99m-HMPAO uptake was decreased intracranially in the right frontal and parietal lobes which had been irradiated. It was also decreased in one well-encapsulated scalp lesion and high in another scalp mass with less defined borders. Possible mechanisms of tumor uptake of these agents are reviewed.
Computer-assisted superimposition of magnetic resonance and high-resolution technetium-99m-HMPAO and thallium-201 SPECT images of the brain.
A method for registering three-dimensional CT, MR, and PET data sets that require no special patient immobilization or other precise positioning measures was adapted to high-resolution SPECT and MRI and was applied in 14 subjects (five normal volunteers, four patients with dementia (Alzheimer's disease), two patients with recurrent glioblastoma, and three patients with focal lesions (stroke, arachnoid cyst and head trauma]. T2-weighted axial magnetic resonance images and transaxial 99mTc-HMPAO and 201Tl images acquired with an annular gamma camera were merged using an objective registration (translation, rotation and rescaling) program. In the normal subjects and patients with dementia and focal lesions, focal areas of high uptake corresponded to gray matter structures. Focal lesions observed on MRI corresponded to perfusion defects on SPECT. In the patients who had undergone surgical resection of glioblastoma followed by interstitial brachytherapy, increased 201Tl corresponding to recurrent tumor could be localized from the superimposed images. The method was evaluated by measuring the residuals in all subjects and translational errors due to superimposition of deep structures in the 12 subjects with normal thalamic anatomy and 99mTc-HMPAO uptake. This method for superimposing magnetic resonance and high-resolution SPECT images of the brain is a useful technique for correlating regional function with brain anatomy.
Nephropathic cystinosis: a case report.
Explore the source record for details and available documents.
Results of stereotactic brachytherapy used in the initial management of patients with glioblastoma.
Recent studies have shown a survival benefit for patients with recurrent glioblastomas treated with stereotactic brachytherapy. On the basis of these encouraging results, we began a prospective study in 1987 to evaluate the use of brachytherapy in patients with newly diagnosed glioblastoma. Patients were considered eligible for this study if they met the following criteria: Karnofsky performance status 70% or greater; tumor size not greater than 5 cm in any dimension; a radiographically well delineated, supratentorial lesion not involving the ependymal surfaces; and pathologically confirmed glioblastoma. We treated 35 such patients between 1987 and 1990 with stereotactic brachytherapy as part of their initial therapy. The treatment protocol involved surgery, partial brain external-beam radiotherapy (59.4 Gy in 33 fractions), and stereotactic brachytherapy with temporary high-activity iodine 125 sources giving an additional 50 Gy to the tumor bed. Chemotherapy was not used in the initial management of these 35 patients. To compare our results with those obtained in a matched control group, we identified 40 patients with glioblastoma treated with surgery and external radiotherapy, with or without chemotherapy, between 1977 and 1986 at our institution. These patients had clinical and radiographic characteristics that would have made them eligible for the brachytherapy protocol. Survival rates at 1 and 2 years after diagnosis were 87% and 57%, respectively, for patients receiving brachytherapy versus 40% and 12.5%, respectively, for the controls (P less than .001). We conclude that stereotactic brachytherapy improves the survival of patients with glioblastoma when it can be incorporated into the initial treatment approach. Unfortunately, only about one in four patients with glioblastoma are suitable candidates for brachytherapy at the time of initial presentation.
Ataxic sensory neuropathy and dorsal root ganglionitis associated with Sjögren's syndrome.
Thirteen patients, 11 women and 2 men, developed sensory and autonomic neuronopathies in association with features of primary Sjögren's syndrome. In 11, Sjögren's syndrome had not been previously diagnosed at the time of neurological presentation. All had prominent loss of kinesthesia and proprioception. Pain and thermal sensibility were less severely affected. Most had evidence of autonomic insufficiency. In some this was severe, with Adie's pupils, fixed tachycardia, and orthostatic hypotension. The course ranged from an abrupt, devastating onset to indolent progression over years. Stabilization or functional improvement occurred in 6 patients, 2 of whom received no drug therapy. Sensory nerve conduction studies and examination of nerve biopsy specimens demonstrated a wide spectrum in the severity of loss of large myelinated fibers. The cutaneous nerves of 6 patients had perivascular mononuclear infiltrates without necrotizing arteritis. Examination of biopsy specimens of dorsal root ganglia in 3 patients revealed lymphocytic (T-cell) infiltration in the dorsal roots and ganglia, with focal clusters around neurons. In the more mildly affected ganglia, individual sensory neurons were undergoing degeneration. In the most advanced case, very few neurons remained. The possibility of Sjögren's syndrome should be considered in patients, especially women, who develop acute, subacute, or chronic sensory and autonomic neuropathies, with ataxia and kinesthetic loss.
Sjögren's syndrome mimicking multiple sclerosis.
Explore the source record for details and available documents.
Arteriovenous malformation of the great vein of Galen associated with patent ductus arteriosus. Report of three cases and review of the literature.
The arteriovenous malformation of the vein of Galen (AVG), composed of a fistula between medium to large arteries and the vein of Galen, is frequently fatal in the neonatal period. We now report three cases of infants with AVG and associated patent ductus arteriosus (PDA), and review the literature for these associated findings. The presence of a PDA can result in severe vascular derangement in the postoperative period, and further complicate management of these infants. Analysis of this abnormal central circulation may contribute to a better understanding and therefore outcome for this unfortunate group of patients.
Historical vignette. The neurosurgeon's neurosurgeon: cushing operates on a Penfield.
In his autobiography, Dr. Wilder Penfield relates the medical history of his sister, Mrs. Ruth Inglis, who developed a right frontal oligodendroglioma. Penfield performed the initial craniotomy on her, and after her death, reported the case in a paper on frontal lobe function in humans. Although Penfield has provided more than adequate information on certain aspects of his sister's illness, little has been published concerning her subsequent operation performed by Dr. Harvey Cushing at the Peter Bent Brigham Hospital. We feel this case is significant for several reasons. First, it sheds some light on Penfield's personal relationship with Cushing and his sister; it also shows the deep interest that Dr. Cushing took in his patients. Second, this case nicely illustrates how Cushing used his postoperative drawings to make his operative notes more precise. Finally, we see a sample of the work done by Dr. Louise Eisenhardt as pathologist at the Peter Bent Brigham Hospital.
Don't drink and dive.
Explore the source record for details and available documents.
Neurosurgical travel club.
Explore the source record for details and available documents.
Stereotactic radiosurgery of the brain using a standard linear accelerator: a study of early and late effects.
Between February 1986 and December 1988, 44 patients were treated with stereotactic radiosurgery using a standard linear accelerator. Twenty one patients were treated for cerebrovascular abnormalities and 23 patients were treated for intracranial tumors. Fifteen of the 23 patients treated for intracranial tumors had received previous radiotherapy. The range of doses given by radiosurgery was 1000-2500 cGy. Nausea and vomiting occurred in seven patients within six hours of treatment. The incidence and symptoms were correlated with the dose of radiation to the vomiting center (area postrema) with the median dose to the postrema in symptomatic patients being 618 cGy compared to a range of less than 5 to 184 cGy in the remaining 36 asymptomatic patients. Temporary alopecia occurred in a single patient who received 400 cGy to the scalp. Alopecia did not occur in the remaining 43 patients who received from less than 5 to 175 cGy. Two patients treated for arteriovenous malformations developed an enhancing lesion on CT scanning (one with cerebral edema) on follow-up CT scanning six and twenty-eight months following radiosurgery. The location of these enhancing lesions corresponded to the volumes treated. In one patient, the enhancing pattern and edema disappeared within 18 months of treatment and no neurological deficits developed. Aphasia occurred in one patient treated for a recurrent glioma two hours following treatment to the left temporal lobe and cleared within 12 h of radiosurgery. One patient with an arteriovenous malformation of the pons developed weakness of the contralateral arm and leg six weeks following treatment and this has slowly resolved over the last 12 months. In conclusion, the complications to date have been self-limited and appear to be directly related to the dose and area of brain treated. Prior radiation therapy has not been associated with increased risk of complication in patients treated with radiosurgery for recurrent tumors to date.
Clinical patterns of failure following stereotactic interstitial irradiation for malignant gliomas.
The vast majority of patients treated for malignant gliomas with surgery, conventional radiation therapy, and systemic chemotherapy recur within 2 cm of their original disease site as documented by CT scanning. We have analyzed the clinical patterns of failure in patients treated with stereotactic interstitial irradiation (brachytherapy) for malignant gliomas in order to determine if this modality has altered the recurrence pattern in this disease. Between December 1985 and December 1989, 53 patients with malignant glioma were treated with stereotactic interstitial irradiation using temporary high activity iodine-125. Thirty-three patients were treated as part of a primary treatment protocol that included 5940 cGy external beam prior to implantation. Twenty patients were treated at time of recurrence. The median dose of radiation given at implantation was 5040 cGy for the primary lesions and 5450 cGy for the recurrent lesions. Twenty-two patients have suffered relapse as documented by clinical and radiographic studies. The predominant patterns of failure in these 22 patients were in the margins of the implant volume (8) and distant sites (10) within the CNS (distant ipsilateral or contralateral hemisphere, spinal axis) or extraneural. Thus, marginal and distant recurrences accounted for 82% of the relapses in our patients. We conclude stereotactic interstitial irradiation has changed the recurrence pattern in patients with malignant glioma with true local recurrence no longer being the predominant pattern of failure as is seen with conventional therapy.
The identification of adrenergic receptors in human pial membranes.
Recent experimental work has suggested that the adrenergic nervous system is important in regulating cerebral blood flow under conditions of hypoxia and systemic arterial hypertension. Although previous investigations have demonstrated the presence of adrenergic neurons adjacent to human cerebral vessels, the nature of adrenergic receptors on human cerebral blood vessels remains poorly defined. The present study was performed to characterize adrenergic reception on membranes prepared from human pia, a rich source of small blood vessels, using radioligand binding techniques. Adrenergic membrane receptors were characterized using the binding of [3H]dihydroalprenolol for the beta subtypes and [3H]prazosin and [3H]yohimbine for the alpha subtypes. Displaceable binding was demonstrated with each agent. A small series of adrenergic agents competed for the [3H]dihydroalprenolol, [3H]yohimbine, and [3H]praz binding sites in a fashion suggesting the presence of alpha 1-, alpha 2-, beta 1-, and beta 2-receptors on the vessels within human pia.
The treatment of recurrent brain metastases with stereotactic radiosurgery.
Between May 1986 and August 1989, we treated 18 patients with 21 recurrent or persistent brain metastases with stereotactic radiosurgery using a modified linear accelerator. To be eligible for radiosurgery, patients had to have a performance status of greater than or equal to 70% and have no evidence of (or stable) systemic disease. All but one patient had received prior radiotherapy, and were treated with stereotactic radiosurgery at the time of recurrence. Polar lesions were treated only if the patient had undergone and failed previous complete surgical resection (10 patients). Single doses of radiation (900 to 2,500 cGy) were delivered to limited volumes (less than 27 cm3) using a modified 6MV linear accelerator. The most common histology of the metastatic lesion was carcinoma of the lung (seven patients), followed by carcinoma of the breast (four patients), and melanoma (four patients). With median follow-up of 9 months (range, 1 to 39), all tumors have been controlled in the radiosurgery field. Two patients failed in the immediate margin of the treated volume and were subsequently treated with surgery and implantation of 125I to control the disease. Radiographic response was dramatic and rapid in the patients with adenocarcinoma, while slight reduction and stabilization occurred in those patients with melanoma, renal cell carcinoma, and sarcoma. The majority of patients improved neurologically following treatment, and were able to be withdrawn from corticosteroid therapy. Complications were limited and transient in nature and no cases of symptomatic radiation necrosis occurred in any patient despite previous exposure to radiotherapy. Stereotactic radiosurgery is an effective and relatively safe treatment for recurrent solitary metastases and is an appealing technique for the initial management of deep-seated lesions as a boost to whole brain radiotherapy.
The role of stereotactic radiosurgery in the management of intracranial tumors.
With the availability of gamma knife units and the development of modified linear accelerators, there is new interest in radiosurgery, especially as it applies to intracranial tumors. Among its advantages are the ability to precisely localize tumor and through small beam sizes deliver steep dose gradients at the field edges. This sharp dose gradient allows for the prescribed dose of radiation to be given to a tumor while avoiding vital structures only millimeters away. Radiosurgery has produced good results in the treatment of inoperable arteriovenous malformations and can be used as the sole curative therapy for small, radiographically distinct, benign noninvasive tumors. It is also used as salvage therapy in recurrent benign or malignant tumors that have previously been irradiated.
Role of stereotactic radiosurgery with a linear accelerator in treatment of intracranial arteriovenous malformations and tumors in children.
Between 1986 and 1988, 16 children were treated for 10 arteriovenous malformations and 6 recurrent intracranial tumors with stereotactic radiation therapy using a modified Clinac 6/100 linear accelerator. The median age of our patients was 10.5 years. For the group with arteriovenous malformation, follow-up ranged from 6 months to 37 months (median was 20 months). No patient bled during the follow-up period. Five of eight patients with follow-up longer than 12 months have achieved complete obliteration of their arteriovenous malformation by angiogram. The four remaining patients who have not achieved a complete obliteration are awaiting their 2-year posttreatment angiogram. The other patient has been treated within the year and have not yet been studied. Five of the six recurrent tumor patients are alive with a median follow-up of 8 months. The remaining patient was controlled locally, but he died of recurrent disease outside the area treated with radiosurgery. The radiographic responses of these patients have included three complete responses, two substantial reductions in tumor volume (greater than 50%) and one stabilization. Despite previous radiotherapy, there have been no significant complications in these patients. We conclude that stereotactic radiation therapy using a standard linear accelerator is an effective and safe technique in the treatment of selected intracranial arteriovenous malformations and tumors in children. In addition, stereotactic radiosurgery may have unique applications in the treatment of localized primary and recurrent pediatric brain tumors.