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Biomedical subjects

G R Nugent

Publications and source records attributed to G R Nugent.

At least 19 recordsLinked to original sources

Granulocytic sarcoma presenting as an epidural mass with acute paraparesis in an aleukemic patient.

Granulocytic sarcomas are rare tumors composed of granulocytic precursor cells. They are most commonly encountered in patients with acute myelogenous leukemias and myeloproliferative disorders in blast crisis. Rarely, patients presenting with granulocytic sarcoma show no evidence of acute leukemia. The authors report an aleukemic patient with acute paraparesis from an epidural granulocytic sarcoma. Only five such cases have been reported previously. Immunoperoxidase stain for lysozyme and chloroacetate esterase stain were used to prove the myeloid origin of the tumor cells.

Aged

Pressure changes within a chronic subdural hematoma during hemodialysis.

Spontaneous intracranial hemorrhage is not an infrequent complication of systemic anticoagulation, as occurs in hemodialysis. The neurological symptoms of subdural hematoma may be similar to those of dialysis disequilibrium. The pressure within a subdural fluid collection was monitored in a patient undergoing hemodialysis. The patient was known to become unresponsive during previous dialysis treatments. The initial pressure within the subdural cavity was measured to be -10.0 cm H2O prior to dialysis. The pressure within the collection decreased to a minimum value of -19.4 cm H2O during dialysis and stabilized at -16.4 cm H2O at the termination of dialysis. The neurological status changed subjectively during the procedure, with the patient becoming unresponsive to verbal stimuli as the intracranial pressure reached a minimum. These findings represent a syndrome similar to aliquorrhea, or low cerebrospinal fluid pressure within an otherwise asymptomatic subdural hematoma. Previously only increased intracranial pressure has been reported with hemodialysis.

Chronic Disease

Technique of stereotactic biopsy of two cranial target employing spherical coordinates to define a single trajectory.

A 'spherical coordinate system' has been developed to allow either stereotactic biopsy of two intracranial lesions using a single predetermined trajectory or biopsy of a single lesion through an existing burr hole. By means of the Gildenberg technique, the CT coordinates of the targets (or target and burr hole) are obtained. These are employed in three simple trigonometric equations to give three coordinates-two angles for the probe carrier (theta and alpha) and the radius (T) of a sphere, defined by one target as the center and the other target on the surface. These can be utilized in the Todd-Wells stereotactic frame. This system was evaluated using hollow skulls and crossed 30-gauge wire for phantom targets. The system was tried on ten different target combinations, and eight successful trajectories were obtained to within 3 mm. Two target combinations were inaccessible because of technical limitations of the Todd-Wells frame. This 'spherical coordinate system' can decrease the time to localize multiple targets as well as minimize the number of passes.

Biopsy

Transient ischemic attacks due to increased platelet aggregation and adhesiveness. Ultrastructural and functional correlation.

The authors report 22 cases of transient ischemic attacks (TIA's) manifested by amaurosis fugax or hemiparesis or paresthesia of less than 24 hours' duration. None of the patients demonstrated 1) evidence of atherosclerotic cerebral vascular disease on angiography, 2) evidence of intracranial lesion on brain scan, 3) cardiac source of emboli, 4) arteritis or collagen disease, or 5) history of migraine. The only abnormalities found to explain the TIA's were abnormally increased platelet adhesiveness and/or aggregation. All of these patients were followed from 1 to 5 years, and had repeated coagulation studies. Treatment with antiplatelet drugs showed an excellent clinical response with associated decrease in platelet adhesiveness and aggregation. Discontinuance of the antiplatelet drug resulted in a recurrence of the TIA's which coincided with an increase in aggregation and adhesiveness. In two cases the platelet morphology was studied by transmission and scanning electron microscopy. It appears that there is a specific group of patients with TIA's in whom the sole cause of the attack is an abnormality of platelet function. For these people there is a specific therapy and a method monitoring the treatment.

Adolescent

Communicating hydrocephalus as a cause of aqueductal stenosis.

Eleven cases of presumed aqueductal stenosis with onset of symptoms after the first decade were reviewed. Ten patients had complete occlusion and one a high-grade stenosis. In 10, the dilated lateral ventricles caused a marked inferior displacement of the third ventricle. Postshunting diagnostic studies on six of these patients revealed ascent of the third ventricle, and in three of these the aqueduct was shown to be patent. It appears that in some cases of advanced communicating hydrocephalus the descending third ventricle kinks or pinches shut the aqueduct, adding an obstructive component which accelerates the clinical picture. The mechanism and clinical features of this process are discussed.

Adolescent

Carpal tunnel syndrome: report of 430 operations.

Analyzed are data on 430 operations in 326 patients for median nerve compression at the wrist. Follow-up data from a patient self-evaluation questionnaire were available for 71% of patients. Incidence was highest in the fifth and sixth decades of life, and 65% of patients were female. For most patients, symptoms were worse at night or with excessive hand use or both. Self-evaluation questionnaires showed total relief of symptoms after operation in 51% of cases, 75% or greater improvement in 31%, and 50% or greater improvement in 10%. The dominant hand was more severely involved in two thirds of the patients and 78% of patients had occupations involving considerable use of their hands, suggesting that an occupational factor might be involved in the genesis or aggravation of median nerve compression.

Adolescent

Unusual presentation of a choroid plexus papilloma.

An unusual case of a choroid plexus papilloma which completely isolated the right temporal and occipital horns from the remainder of the ventricular system is presented. The tumor secreted large quantities of cerebrospinal fluid and also bled into this obstructed cavity. A gross total removal was accomplished.

Cerebral Ventricle Neoplasms

Ependymal cyst of the thoracic spinal cord.

A unique case of an ependymal cyst on the anterior aspect of the thoracic spinal cord in a woman aged 68 years is described. Clinical signs were precipitated by trauma. Recovery of function, while incomplete, was remarkably good after extirpation of the cyst.

Aged