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Biomedical subjects

D Hadley

Publications and source records attributed to D Hadley.

At least 55 records · Page 3Linked to original sources
PubMed1991

A comparison of imaging techniques with surgical experience in orbital injuries. A prospective study.

The aim of the study is to compare the effectiveness of computerised tomography (CT) and magnetic resonance (MR) imaging in diagnosing herniation and entrapment of orbital soft tissues in orbital fractures. 15 consecutive patients with clinical signs and symptoms of medial orbital wall injury were examined with CT and MR. The data were subsequently compared with the findings of the surgical exploration with regard to the extent of the wall fractures, the presence of soft tissue herniation and its entrapment. CT and MR were equally accurate in demonstrating or excluding orbital wall fractures but both modalities slightly underestimated their incidence. CT and MR underestimated the actual incidence of soft tissue herniation and entrapment when compared with the surgical findings but the extent of soft tissue herniation and entrapment were demonstrated more clearly by MR than by CT scanning. MR imaging when available should therefore be used as the initial imaging modality and CT held in reserve for confirmation as positioning in the MR unit is easier and more comfortable for recently injured patients who may well have other injuries.

Adipose Tissue↗
PubMed1990

The time course of vasogenic oedema after focal human head injury--evidence from SPECT mapping of blood brain barrier defects.

We have tomographically mapped changes in the blood brain barrier (BBB) (99 mTc Pertechnetate) in 20 patients with acute contusions, and four with acute subdural haematomas in situ. The changes were related to regional CBF, (99 mTc HMPAO SPECT) T2 weighted MRI scans, CT abnormalities and the clinical features. Seventy-five percent of contusions were accompanied by a BBB abnormality, usually a "halo" around the lesion, which was more common in scans made after the second day. All contusions demonstrated "oedema" as a zone of "T2" signal on MRI or a zone of lucency on CT, and all were accompanied by a focal zone of low CBF on SPECT. Early contusional oedema appears to be cytotoxic but in certain cases, delayed blood brain barrier lesions develop, suggesting a vasogenic component.

Acute Disease↗
PubMed1990

Double giant fusiform aneurysms of the posterior cerebral artery.

Subarachnoid hemorrhage in a patient with two giant fusiform aneurysms arising from the posterior cerebral artery was treated by clipping the P2 segment of the artery, proximal to the first aneurysm. This combination of aneurysms has not previously been reported.

Cerebral Angiography↗
PubMed1989

Transverse myelitis occurring during pregnancy in a patient with systemic lupus erythematosus.

Myelopathy is a well recognised but infrequent neurological manifestation of systemic lupus erythematosus (SLE). The case of a 27 year old woman with SLE of seven years' duration who developed a spastic paraparesis during her second pregnancy is reported. Magnetic resonance imaging did not show any intrinsic abnormality of the spinal cord. Anticardiolipin antibody was weakly positive and C4 was low. The patient responded dramatically to steroids.

Adult↗
PubMed1989

Blindness in eclampsia: CT and MR imaging.

Three cases of cortical blindness complicating eclampsia are described, with magnetic resonance imaging (MRI) and X-ray computed tomography (CT). The correspondence of MRI lesions (hyperintense on T2 weighted, and hypointense on T1 weighted sections) and low attenuation lesions on CT scan indicated ischaemia rather than haemorrhage as the pathological mechanism.

Adult↗
PubMed1988

Temporal physiochemical changes during in vitro relaxation time measurements: the cerebrospinal fluid.

Documented relaxation time measurements of body fluids such as cerebrospinal fluid (CSF) vary considerably. This may be largely due to lack of an appropriate method of maintaining the in vivo physiological and biochemical characteristics of the fluid. We have developed an in vitro technique that maintains the in vivo characteristics of body fluid samples for a sufficiently long period to establish the true relaxation times. To illustrate this we studied changes in CSF pH, pO2, and pCO2, first as it equilibrated with air and then under anaerobic conditions as found in vivo. Relaxation times of CSF were then studied under aerobic and anaerobic conditions. Under the particular aerobic conditions used the pH and pO2 of CSF increased quickly and pCO2 fell within the first 30 min. By 3-4 h equilibration with air was complete. The T1 and T2 relaxation times of CSF decreased by 14 and 16%, respectively, as a result of these physicochemical changes. It is important that such changes be considered when relaxation measurements of any body fluid are performed in vitro and efforts to maintain the in vivo milieu should not be neglected.

Aerobiosis↗
PubMed1988

Brain and intracranial cavity volumes: in vivo determination by MRI.

Brain volume is altered by pathological processes such as swelling or atrophy yet until now this is a parameter which could only be determined at post mortem. This paper describes a non-invasive technique using MRI which permits the in vivo determination of brain volume (BV), intracranial cavity volume (ICV), ventricular, cortical sulcal and total intracranial CSF volumes. The technique was applied to 40 normal volunteers (20 males, 20 females) to investigate the variation of these parameters with age and sex after normalisation with respect to ICV. There was found to be a significant decrease in normalised brain volume between the ages of 20 and 60 years in males by 1.6% per decade. In females the decrease was less (0.5%) but was not statistically significant. This technique will make it possible, for the first time, to investigate prospectively the correlation between mental function and brain volume in illness and ageing.

Adult↗
PubMed1986

Use of magnetic resonance imaging to measure intracranial cerebrospinal fluid volume.

Magnetic resonance imaging was used to measure intracranial extraventricular and ventricular cerebrospinal fluid (CSF) volume. In 10 normal subjects lateral ventricular and extraventricular intracranial CSF volumes were 25.3 +/- 4.6 ml (mean +/- SD) and 97.6 +/- 6.6 ml, respectively (total 122.8 +/- 38.7). These volumes were measured in 4 patients and the results were: 11.0 ml ventricular volume, 68.7 ml total cranial CSF in the patient with benign intracranial hypertension; 606.6 ml ventricular, 174.1 ml total in the patient with hydrocephalus due to a blocked ventriculo-peritoneal (V-P) shunt; 83.4 ml ventricular, 108.5 ml total in the patient with normal pressure hydrocephalus; and 52.7 ml ventricular, 181.0 ml total in the patient with cerebral atrophy due to Alzheimer's disease. The technique gave highly reproducible results (SD less than 5.7% of mean value). It may be useful in differential diagnosis and as an objective means of monitoring therapy or progress in conditions such as cerebral atrophy, hydrocephalus, and benign intracranial hypertension.

Adolescent↗
PubMed1984

Orchiectomy does not selectively increase adrenal androgen concentrations.

Prostatic carcinoma is androgen dependent and, therefore, treated by orchiectomy. However, adrenal androgen secretion remains intact after orchiectomy, and several investigators even reported an increase in serum adrenal androgen concentrations after orchiectomy. Such an increase in androgen secretion theoretically could promote tumor recurrence. To investigate this question, we obtained multiple blood samples from 10 men before, within 1 week after, and up to 6 months after orchiectomy for prostatic carcinoma. Serum testosterone concentrations became unmeasurable (less than 40 ng/dl) after orchiectomy. Three of the 10 patients had transient increases of at least 50% in both serum dehydroepiandrosterone (DHA) and cortisol after orchiectomy, presumably due to surgical stress, but mean serum DHA and DHA sulfate (DHAS) did not increase in the group as a whole. Subsequently, serum DHA and DHAS concentrations were similar to preoperative values in all patients. Therefore, we find no evidence to support the hypothesis that adrenal androgen concentrations increase after orchiectomy.

Adrenal Glands↗
PubMed1979

Peripheral neuropathy associated with cis-dichlorodiammineplatinum (II) treatment.

Peripheral neuropathy developed in two cases of recurrent bladder carcinoma treated with Cis-dichlorodiammineplatinum (II) (DDP) at a dose of 75 mg/m2 IV every 3 weeks. The neuropathy appeared in both patients while they were achieving a subjective and objective response to DDP. The neuropathy was reversible in one patient. In the other patient, a disabling sensory neuropathy progressed despite cessation of therapy. The temporal relationship between the neurological symptoms and the administration of DDP implicate this drug as the possible causative agent in the peripheral neuropathy.

Aged↗
PubMedDate not supplied

MR relaxation times of cerebrospinal fluid.

A review of 15 recent publications purporting to provide the relaxation times of CSF reveals a considerable disparity in the quoted results, by a factor of five in terms of T1 (range 1,000 to 5,500 ms) and by a factor of 16 for T2 (range 166 to 2,640 ms). In this article measurements are performed independently on both a spectrometer and an imager. The results indicate that for CSF T1 is greater than 3,000 ms and T2 is approximately 2,000 ms at 6 MHz. The vast differences in relaxation behaviour between CSF and other body tissues have considerable clinical implications and present profound diagnostic opportunities. The application of this knowledge to ventriculography, myelography, and image contrast methodology is discussed.

Cerebrospinal Fluid↗
PubMedDate not supplied

Manic-depression and the norepinephrine transporter gene.

Six multigenerational pedigrees containing multiple cases of manic-depression were genotyped with a DNA polymorphism for the norepinephrine transporter (NET) gene. Using both parametric and nonparametric methods, no evidence of linkage between manic-depression and the NET gene was found.

Adolescent↗
PubMedDate not supplied

Acquired bilateral superior oblique palsy: a localising sign in the dorsal midbrain.

Bilateral superior oblique palsy is an uncommon ocular motility problem, the commonest cause being closed head trauma. Two cases, both adults, are presented in whom bilateral superior oblique palsy occurred as a result of neoplastic infiltration of the dorsal midbrain in the region of the anterior medullary velum. In the absence of a history of head trauma, the presence of an acquired bilateral superior oblique palsy is a definite sign of a single lesion in the region of the decussation of the trochlear nerves and appropriate imaging is indicated.

Adolescent↗