Biomedical subjects
Publications and source records attributed to B Tress.
Lymphocytic hypophysitis is a primary inflammatory disorder of the pituitary gland, which may cause panhypopituitarism. The majority of cases occur in women during the peripartum period and it is rare in men. We present a case, initially presenting with recurrent hypoglycaemic episodes, in a man with previously well-controlled type 2 diabetes mellitus.
BACKGROUND AND PURPOSE: The Echoplanar Imaging Thrombolysis Evaluation Trial (EPITHET) tests the hypothesis that perfusion-weighted imaging (PWI)-diffusion-weighted imaging (DWI) mismatch predicts the response to thrombolysis. There is no accepted standardized definition of PWI-DWI mismatch. We compared common mismatch definitions in the initial 40 EPITHET patients. METHODS: Raw perfusion images were used to generate maps of time to peak (TTP), mean transit time (MTT), time to peak of the impulse response (Tmax) and first moment transit time (FMT). DWI, apparent diffusion coefficient (ADC), and PWI volumes were measured with planimetric and thresholding techniques. Correlations between mismatch volume (PWIvol-DWIvol) and DWI expansion (T2(Day 90-vol)-DWI(Acute-vol)) were also assessed. RESULTS: Mean age was 68+/-11, time to MRI 4.5+/-0.7 hours, and median National Institutes of Health Stroke Scale (NIHSS) score 11 (range 4 to 23). Tmax and MTT hypoperfusion volumes were significantly lower than those calculated with TTP and FMT maps (P<0.001). Mismatch > or =20% was observed in 89% (Tmax) to 92% (TTP/FMT/MTT) of patients. Application of a +4s (relative to the contralateral hemisphere) PWI threshold reduced the frequency of positive mismatch volumes (TTP 73%/FMT 68%/Tmax 54%/MTT 43%). Mismatch was not significantly different when assessed with ADC maps. Mismatch volume, calculated with all parameters and thresholds, was not significantly correlated with DWI expansion. In contrast, reperfusion was correlated inversely with infarct growth (R=-0.51; P=0.009). CONCLUSIONS: Deconvolution and application of PWI thresholds provide more conservative estimates of tissue at risk and decrease the frequency of mismatch accordingly. The precise definition may not be critical; however, because reperfusion alters tissue fate irrespective of mismatch.
Thyrotoxicosis due to Graves disease is a relatively common endocrine disorder. The occurrence of a prolactinoma with co-secretion of growth hormone (GH) is on the other hand, rare. We report the rare co-existence of Graves' disease in a patient with macroprolactinoma and GH hypersecretion and describe the successful response to medical therapy with dopamine agonist and antithyroid therapy. We hypothesize that hyperprolactinaemia played a role in promoting autoimmune thyroid disease in our patient and that treatment of hyperprolactinaemia may have been important in suppressing autoimmune disease activity in Graves' disease. This case also reflects on the close and complex interactions between thyroid hormones, prolactin (PRL), GH and testosterone (T).
BACKGROUND AND PURPOSE: Perfusion-weighted MRI has been shown to be useful in the early identification of cerebral tissue at risk of infarction during acute ischemia. Identification of threshold perfusion measures that predict infarction may assist in the selection of patients for thrombolysis. METHODS: Mean transit time (MTT), regional cerebral blood flow (rCBF), and regional cerebral blood volume (rCBV) maps were generated in 35 acute stroke patients (17 treated with tissue plasminogen activator and 18 control patients) imaged within 6 hours from symptom onset. Day 90 outcome infarcts (T2-weighted MRI) were superimposed on acute MTT, rCBF, and rCBV maps. Perfusion-weighted MRI measures were then calculated for 2 regions: infarcted and salvaged tissue. RESULTS: MTT was prolonged by 22% in infarcted regions relative to salvaged tissue (P<0.001). rCBF was 10% lower in infarcted tissue than in salvaged regions (P<0.01). rCBV did not differ significantly between infarcted and salvaged regions. When reperfusion occurred, tissue with more severely prolonged MTT was salvaged from infarction relative to patients with persistent hypoperfusion (P<0.05). In contrast, rCBF in salvaged regions did not differ between patients with and without reperfusion. In reperfused patients, an inverse correlation (R=0.93, P<0.001) was found between time of initial MRI scan and MTT delay in salvaged tissue. CONCLUSIONS: Both increases in MTT and decreases in rCBF predict infarction. Differences in MTT also predict salvage in more severely hypoperfused tissue after reperfusion, suggesting that it is the most clinically useful quantitative perfusion measure. Perfusion thresholds for infarction need to be assessed in the context of symptom duration.
OBJECTIVE: To investigate whether patients with first-episode psychosis or chronic schizophrenia have an increased incidence of magnetic resonance imaging (MRI) brain abnormalities compared with control subjects. METHOD: Totally 340 clinical MRI reports [Controls (n=98), first-episode psychoses (n=152), chronic schizophrenia (n=90)] were reported by a neuroradiologist blind to diagnosis and subsequently categorized using referral criteria (immediate, urgent, routine or no referral). RESULTS: Thirty percent of all scans were reported by a neuroradiologist as abnormal, but the majority required no referral. Patients with chronic schizophrenia were more likely to have clinically significant abnormal scans than patients with first episode psychosis or control subjects. In four patients the MRI findings led to the discovery of previously unsuspected pathology. CONCLUSION: Patients with chronic schizophrenia have an increased prevalence of incidental brain abnormalities. A small proportion of patients with chronic schizophrenia and first-episode psychosis benefitted directly from MRI scanning.
OBJECTIVE: To compare the utility of temporal lobe magnetic resonance imaging (MRI) and single-photon emission tomography (SPET) scanning in discriminating between subjects with Alzheimer's disease (AD) and age-matched controls. METHODS: Thirty subjects with NINCDS-ADRDA AD (23 probable AD, 5 possible AD, 2 definite AD) and 22 age- and sex-matched controls underwent T1-weighted coronal MRI scanning (0.3 T) and technetium 99m-HMPAO SPET scanning. MRI scans were analyzed using a digitizer system with volumes of hippocampus, amygdala, entorhinal cortex, parahippocampal gyrus, and whole cerebral cortex calculated. From SPET scans, regional cerebral blood flow (rCBF) was assessed in anterior and posterior frontal, parietal, occipital, and mesial temporal cortex using a region of interest analysis with the cerebellum as a reference area. RESULTS: Using MRI, the areas that best separated groups were left hippocampal and left amygdala volume, resulting in correct classification (patient vs. control) in 79% of cases (sensitivity 77%, specificity 82%). Exactly the same proportion of subjects were correctly classified by SPET, with the most discriminating rCBF changes being left parietal and right posterior frontal. Combining information from both scans improved the proportion of correctly classified subjects in a discriminant function to 90% (sensitivity 93%, specificity 86%; only 2 AD and 3 controls misclassified). All AD subjects had abnormalities on MRI and/or SPET (sensitivity for combined examinations 100%), while abnormalities on both MRI and SPET had a positive predictive value of 100% for dementia (including the detection of one control subject who later had dementia). Significant correlations between MRI and SPET measures were seen in control subjects but not in patients. CONCLUSION: Both 0.3 T MRI and single rotating gamma camera SPET were equally useful in separating AD subjects from age-matched controls, although the combination of both significantly enhanced discrimination. In particular, all AD subjects had abnormalities on either MRI or SPET and both techniques may have an important role in assisting with clinical diagnosis, though replication in other centers and examination of differentiation of AD from other causes of dementia need to be examined.
Sphenoid sinus mucocoeles represent 1% of all paranasal sinus mucocoeles. We describe a case of a sinus mucocoele with an atypical presentation comprising the sudden onset of a complete ophthalmoplegia. There was good recovery following drainage of the mucocoele.
Echoplanar magnetic resonance imaging (EPI) enables rapid, non-invasive imaging and analysis of cerebral pathophysiology in acute stroke. It represents an important clinical advance over computed tomography (CT) and conventional magnetic resonance (MR) scanning. It can rapidly delineate infarcted cerebral tissue and distinguish acute from chronic stroke. In addition, EPI has the potential to quickly determine the presence and degree of potentially viable brain tissue in the ischaemic penumbra. Thrombolysis is thought to reperfuse the penumbra and hence reduce infarct size. The thrombolytic agent tissue plasminogen activator (t-PA) improves outcome in ischaemic stroke when administered within the first 3 hours of onset. However, there is a significant risk of haemorrhage, and the time window for benefit may well exceed 3 hours in some patients. Hence, by facilitating diagnosis of 'at-risk' tissue in the ischaemic penumbra, a major clinical role of EPI may well become the rational selection of patients for acute interventional stroke therapy.
OBJECTIVE: To determine the difference in outcome among elderly people with major depression who do and do not have severe white matter lesions on magnetic resonance imaging. DESIGN: Follow up study. SETTING: Two psychiatric and two general hospitals in Melbourne, Australia. SUBJECTS: 60 depressed subjects aged over 55 referred to hospital psychiatric services with major depressive disorder meeting American Psychiatric Association (DSM-IIIR) criteria. MAIN OUTCOME MEASURE: Proportion with good outcome as determined by full recovery from initial illness and no evidence of depressive relapse or cognitive decline during follow up among those with and without lesions. RESULTS: Mean (SD) follow up was 31.9 (9.9) months. Survival analysis showed a significant effect of severe lesions on time to poor outcome (P=0.04), with median survival 136 days in those with severe lesions compared with 315 days in those without. CONCLUSION: Severe white matter change on magnetic resonance imaging is associated with poor outcome in elderly depressed subjects.
OBJECTIVE: To investigate neuroradiological, endocrinological and clinical differences between delusional and non-delusional depression. DESIGN: A cross-sectional study of depressed subjects. SETTING: Melbourne, Australia. PARTICIPANTS: Sixty-one subjects (inpatients) over the age of 55 meeting DSM-III-R criteria for major depression of whom 22 had delusional subtype of depression. MEASURES: Clinical assessment, including documentation of vascular risk factors. Cognitive assessment by the Cambridge Cognitive Examination (CAMCOG). Magnetic resonance imaging (MRI) scans were performed on a 0.3 Tesla scanner with temporal lobe atrophy, periventricular lesions (PVL) and deep white matter lesions (DWML) rated visually on 4-point scales. A standard 1 mg dexamethasone suppression test (DST) was performed. RESULTS: Subjects with delusional depression had significantly more vascular risk factors than those without delusions. There were no differences in measures of temporal lobe atrophy, PVL, DST results or cognitive test scores, though there was a non-significant trend for DWML to be more prevalent in those with delusions. Delusional depression was associated with a shorter duration of history and more frequent treatment with ECT. CONCLUSIONS: The increase in vascular risk factors and trend towards greater DWML on MRI suggests an organic contribution to delusional depression in the elderly. In contrast to some previous reports, we found no differences in cortical MRI appearance or neuroendocrine measures between groups.
BACKGROUND: Previous work suggests that temporal lobe magnetic resonance imaging (MRI) can distinguish those with dementia of the Alzheimer type (DAT) from healthy age-matched controls. However, its specificity with regard to conditions such as vascular dementia, depression and other disorders associated with cognitive impairment has not been determined. METHODS: We studied 222 subjects using T1 weighted MRI with 5.1 mm coronal slices throughout the temporal lobe. Subjects included: healthy controls (N = 40); DSM-III-R major depression (N = 61); NINCDS/ADRDA DAT (N = 77) and OTHER (N = 44, comprising subjects with vascular dementia, Huntington's disease, schizophrenia, alcohol related cognitive impairment and a group of 'memory complainers'). Hippocampus, amygdala, entorhinal cortex, parahippocampal gyrus and cerebral cortex were rated visually on a 0-3 scale by two experienced neuroradiologists blind to clinical diagnosis. RESULTS: Ratings of temporal lobe atrophy provided good separation between those with AD and all other groups. For example, anterior hippocampal atrophy had a sensitivity of 83% for detecting DAT, a specificity of 80% for controls, 87% for depressed subjects and 89% for OTHER. Other regions were less sensitive, but more specific for the diagnosis of DAT. In particular parahippocampal gyrus and entorhinal cortex had high specificity (97% for depressed subjects and 98% for OTHER). Because of an age-related increase in atrophy, sensitivity was highest for those over the age of 75, while specificity was highest for younger subjects. Significant correlations were observed between atrophy ratings of hippocampus, amygdala, entorhinal cortex and parahippocampal gyrus and CAMCOG memory score and length of history. CONCLUSIONS: Temporal lobe MRI may have an important role in assisting with the clinical diagnosis of DAT, particularly its differentiation from depression and other disorders that may cause diagnostic difficulties in clinical practice.
BACKGROUND: Carotid cavernous fistulae are treatable by various means, one of which is embolization via the superior ophthalmic vein (SOV). The use of this technique over the past 12 years at the Royal Melbourne Hospital, Victoria, Australia, is reviewed. METHODS: Five patients with carotid cavernous fistulas were treated with embolization of the fistula via the surgically isolated SOV. RESULTS: Each patient had successful endovascular closure of the fistula using embolization via the SOV approach. CONCLUSIONS: Treatment of certain types of carotid cavernous fistulas that cannot be closed by the conventional endovascular (arterial and venous) approaches can be successfully closed by using a transvenous approach through the SOV.
OBJECTIVE: To investigate the neuroradiological correlates of age-related cognitive decline in the elderly. DESIGN: A sample of healthy control subjects underwent magnetic resonance imaging (MRI) scanning and cognitive testing. SETTING: Melbourne, Australia. PARTICIPANTS: 40 volunteers over the age of 55 who were spouses of subjects seen in a hospital memory clinic, subjects from a register of normal volunteer subjects (not staff) kept for research purposes or residents of a retirement hostel. MEASURES: Hippocampal and amygdala (HA) atrophy, periventricular lesions (PVL) and deep white matter lesions (DWML) were rated by two radiologists blind to cognitive test score results. Cognitive assessment was by the Cambridge Cognitive Examination (CAMCOG). RESULTS: After controlling for age and education, lower scores on the memory subscale of the CAMCOG were associated with the presence of HA atrophy, but not with DWML or PVL. CONCLUSIONS: HA atrophy on MRI is associated with impaired memory performance in the healthy elderly, while PVL and DWML are not. Further study should determine whether HA atrophy is a risk factor for developing dementia.
OBJECTIVES: To investigate whether the presence of hippocampal atrophy (HCA) on MRI in Alzheimer's disease (AD) leads to a more rapid decline in cognitive function. To investigate whether cognitively unimpaired controls and depressed subjects with HCA are at higher risk than those without HCA of developing dementia. DESIGN: A prospective follow-up of subjects from a previously reported MRI study. SETTING: Melbourne, Australia. PARTICIPANTS: Five controls with HCA and five age-matched controls without HCA, seven depressed subjects with HCA and seven without HCA, and 12 subjects with clinically diagnosed probable AD with HCA and 12 without HCA were studied. They were followed up at approximately 2 years with repeat cognitive testing, blind to initial diagnosis and MRI result. MEASURES: HCA was rated by two radiologists blind to cognitive test score results. Cognitive assessment was by the Cambridge Cognitive Examination (CAMCOG). RESULTS: No significant differences in rate of cognitive decline, mortality or progression to dementia were found between subjects with or without HCA. CONCLUSIONS: HCA was not found to be a predictor of subsequent cognitive decline in this series.
The neuropsychological performance and Magnetic Resonance Imaging (MRI) brain appearance of a consecutive series of 46 in-patients with anorexia nervosa (AN) was compared with that of 41 normal-weight controls. The groups were matched for sex, age, estimated pre-morbid intelligence and education. AN patients who had gained at least 10% of their body weight were retested and rescanned. Controls were retested after a similar interval. The AN group performed significantly worse than the controls on tasks measuring attention, visuospatial ability and memory. On tasks assessing flexibility and learning, no group differences were evident although an examination of deficits in individuals revealed that more anorexics were impaired on both. Following treatment, the AN group improved relative to the control group only on those tasks assessing attention. Comparison of MRI measures showed a significant proportion of anorexics had enlarged lateral ventricles and dilated sulci on both cortical and cerebellar surfaces, but no dilatation was evident for the third and fourth ventricular measures. Improvements were found after treatment on some of the radiological measures but many differences remained. Relationships between morphological brain changes and cognitive impairments were weak. Lower weight, but not duration of illness, was associated with poorer performance on tasks assessing flexibility/inhibition and memory, and with greater MRI ventricular size.
BACKGROUND: White matter changes, as revealed by magnetic resonance imaging (MRI), may occur in depression and Alzheimer's disease. METHOD: T2-weighted MRI scans were performed in 39 control subjects, 61 subjects with NINCDS/ADRDA Alzheimer's disease and 60 subjects with DSM-III-R major depression. Deep white matter lesions (DWML) and periventricular lesions (PVL) were rated on a standard 0-3 scale by two radiologists blind to clinical diagnosis. RESULTS: After controlling for differences in vascular risk factors and current blood pressure, DWML were significantly more common in depressed subjects and PVL in Alzheimer's disease subjects compared to controls. DWML were most common in those presenting in late life with their first ever depression and 50% of such subjects had severe (grade 3) DWML. CONCLUSION: An association between DWML and depression and PVL and Alzheimer's disease is supported. The increase with DWML that occurs with ageing may predispose some elderly subjects to depression.
BACKGROUND: An age-related dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is well recognised in animals, but still remains controversial in humans. There is increasing interest that raised corticosteroid levels, due to activation of the HPA axis, may cause both depressive symptoms and cognitive impairments. Steroid effects on cognition may be via the hippocampus, a major site of corticosteroid action and an important structure involved in learning and memory. METHOD: To investigate this further, we examined the relationship between the dexamethasone suppression test, cognitive function, depressive symptoms and hippocampal atrophy on magnetic resonance imaging (MRI) in 32 normal controls, 49 subjects with NINCDS/ADRDA Alzheimer's disease and 51 patients with DSM-III-R Major Depression. RESULTS: Controlling for differences in dexamethasone concentrations, post-dexamethasone cortisol levels were related to advancing age in controls and depressed subjects. However, among subjects with Alzheimer's disease, post-dexamethasone cortisol levels were independently associated with both minor depressive symptoms and hippocampal atrophy on MRI. CONCLUSION: An association between advancing age and increased HPA axis dysregulation is supported for controls and depressed subjects. In Alzheimer's disease, HPA axis changes were associated with depressive symptoms and hippocampal atrophy. Longitudinal studies are now needed to determine the causal direction of these associations.
We present a case of uncontrolled temporal lobe epilepsy due to a focal left temporal neuronal heterotopia associated with the nevoid-basal-cell carcinoma syndrome. This is the first pathologically described lesion associated with temporal lobe epilepsy in this syndrome. Because the patient's seizures resolved after a modified left anterior temporal lobectomy, this case illustrates that epilepsy in patients with the nevoid basal-cell carcinoma syndrome is potentially curable and should be investigated appropriately.