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Biomedical subjects

E Teasdale

Publications and source records attributed to E Teasdale.

At least 19 recordsLinked to original sources
PubMed2005

Visual evaluation of perfusion computed tomography in acute stroke accurately estimates infarct volume and tissue viability.

OBJECTIVE: To establish the validity of visual interpretation of immediately processed perfusion computed tomography (CT) maps in acute stroke for prediction of final infarction. METHODS: Perfusion CT studies acquired prospectively were reprocessed within six hours of stroke onset using standard CT console software. Four contiguous 5 mm thick images were obtained and maps of time to peak (TTP) and cerebral blood volume (CBV) generated. Volumes of lesions identified only by visual inspection were measured from manually drawn regions of interest. Volumes of tissue with prolonged TTP or reduced CBV were compared with independently calculated volume of infarction on non-contrast CT (NCCT) at 24-48 hours, and with clinical severity using the NIHSS score. Arterial patency at 24-48 h was included in analyses. RESULTS: Studies were analysed from 17 patients 150 minutes (median) after stroke onset. Volume of tissue with prolonged TTP correlated with initial NIHSS (r = 0.62, p = 0.009), and with NCCT final infarct volume when arterial occlusion persisted (r = 0.953, p = 0.012). Volume of tissue with reduced CBV correlated with final infarct volume if recanalisation occurred (r = 0.835, p = 0.001). Recanalisation was associated with lower 24 h NIHSS score (6 (IQR, 5 to 9.5) v 19 (18 to 26), p = 0.027), and in 10 patients given rtPA for MCA M1 occlusion, with lower infarct volume (73 v 431 ml, p = 0.002). CONCLUSIONS: Visual evaluation of TTP and CBV maps generated by standard perfusion CT software correlated with 24-48 hour CT infarct volumes. Comparison of TTP and CBV maps yields information on tissue viability. Perfusion CT represents a practical technique to aid acute clinical decision making. Recanalisation was a crucial determinant of clinical and radiological outcome.

Adult↗
PubMed2002

Myelopathy from intracranial dural arteriovenous fistula.

Dural arteriovenous fistulas arising intracranially are an uncommon cause of progressive myelopathy. This report is of a patient in whom the diagnosis of the condition was confounded by coexisting small vessel cerebrovascular disease.

Aged↗
PubMed2002

Primary medical therapy for acromegaly: an open, prospective, multicenter study of the effects of subcutaneous and intramuscular slow-release octreotide on growth hormone, insulin-like growth factor-I, and tumor size.

Conventional surgery and radiotherapy for acromegaly have limitations. There are few data on the use of the somatostatin analog octreotide (Oct) as primary medical therapy. An open prospective study of 27 patients with newly diagnosed acromegaly was conducted in nine endocrine centers in the United Kingdom. Twenty patients had macroadenomas, and 7 had microadenomas. For the first 24 wk (phase 1), patients received sc Oct in an initial dose of 100 microg, 3 times daily, increased to 200 micro g three times daily after 4 wk in the 13 patients whose mean serum GH remained greater than 5 mU/liter (2 microg/liter). Five-point GH profiles were performed at 0, 4, 12, and 24 wk, and high resolution pituitary imaging using a standard protocol was performed at 0, 12, and 24 wk (magnetic resonance imaging in 25 patients and computed tomography in 2). Tumor dimensions and volumes were calculated by a central, reporting neuroradiologist, and the results were audited by a second, independent neuroradiologist. After 24 wk, 15 patients proceeded to phase 2 of the study with a direct switch to monthly injections of the depot formulation of Oct, Sandostatin long-acting release (Oct-LAR). Further GH profiles were performed at 36 and 48 wk, and pituitary imaging was performed at 48 wk. The median pretreatment serum GH concentration was 30.7 mU/liter (range, 6.7-141.4). During sc Oct, serum GH fell to less than 5 mU/liter in 9 patients (38%), and IGF-I fell to normal in 8 patients (33%). All 27 tumors shrank during sc Oct; for microadenomas the median tumor volume reduction was 49% (range, 12-73), and for macroadenomas it was 43% (range, 6-92). After 24 wk of Oct-LAR (end of phase 2), the GH level was less than 5 mU/liter in 11 of 14 patients (79%), and IGF-I was normal in 8 of 15 patients (53%). In the 15 patients given Oct-LAR (10 macroadenomas), wk 48 scans showed a further overall median tumor volume reduction of 24%. At the end of the study 79% of patients had mean serum GH levels below 5 mU/liter, 53% had normal IGF-I levels, and 73% showed greater than 30% tumor shrinkage. Twenty-nine percent of patients achieved all 3 targets, but no patient with pretreatment GH levels above 50 mU/liter did so at any stage of the study. Primary medical therapy with Oct offers the prospect of normalization of GH/IGF-I levels together with substantial tumor shrinkage in a significant subset of acromegalic patients. This is most likely to occur in patients with pretreatment GH levels less than 50 mU/liter (20 microg/liter).

Acromegaly↗
PubMed2001

Power transcranial Doppler ultrasound in the detection of intracranial aneurysms.

BACKGROUND AND PURPOSE: We sought to perform a large, prospective, multicenter, blinded study comparing power transcranial color duplex sonography (power TCDS) with intra-arterial digital subtraction angiography (IADSA) in the detection of intracranial aneurysms. METHODS: Contemporaneous TCDS and IADSA examinations were performed in 171 subjects with suspected intracranial aneurysm. Via the temporal bone window, a 2-dimensional hand-held noncontrast transcranial duplex ultrasound imaging system was used operating in power and spectral modes. Sonographers were blinded to clinical history and results of brain CT and IADSA. RESULTS: We found that 157 subjects (92%) had an adequate bone window. Sensitivity per patient was 0.78 (95% CI, 0.66 to 0.87) and 0.46 (95% CI, 0.36 to 0.56) for any anterior circulation aneurysms. Sensitivity was 0.35 (95% CI, 0.24 to 0.46) for aneurysms </=5 mm and 0.81 (95% CI, 0.62 to 0.94) for aneurysms >5 mm. Accuracy was lower for aneurysms on the cavernous and terminal internal carotid arteries, including posterior communicating artery origin (0.71; 95% CI, 0.63 to 0.79), than for those on the anterior (0.82; 95% CI, 0.74 to 0.89) or the middle cerebral arteries (0.79; 95% CI, 0.71 to 0.86). CONCLUSIONS: Power TCDS is a promising, inexpensive, noninvasive test for anterior circulation intracranial aneurysms but is less sensitive per aneurysm than alternatives such as CT angiography or MR angiography. Sensitivity is poor for aneurysms </=5 mm in diameter. The internal carotid artery is the most difficult segment to interpret.

Adult↗
PubMed2000

Torticollis due to atlanto-axial rotatory fixation following general anaesthesia.

Atlanto-axial rotatory fixation is uncommon, but should be suspected in any patient developing a torticollis during the recovery period of an operation performed on the head and neck under general anaesthesia. The present case report shows that the condition can occur in adults as well as children. A high degree of suspicion is required to instigate appropriate imaging. CT provides unequivocal proof and will lead to early successful treatment.

Adult↗
PubMed1993

Deficits in iodine-labelled 3-quinuclidinyl benzilate binding in relation to cerebral blood flow in patients with Alzheimer's disease.

A loss of acetylcholine is one of the most consistent neurochemical findings in Alzheimer's disease (AD) post-mortem, but the debate concerning receptor abnormalities is unresolved. The aim of this investigation was to measure the density of acetylcholine muscarinic receptors in AD patients at various stages in the disease (N = 8) by synthesising a radio-iodinated version of quinuclidinyl benzilate QNB, a potent muscarinic antagonist. Deficits were identified by comparison with a control data set obtained from four elderly volunteers and then compared to the deficit in total functional activity in the same brain regions measured using the cerebral perfusion tracer technetium-99m hexamethylpropylene amine oxime. Iodine-123 (R,R)quinuclidinyl benzilate (QNB) was synthesised using a CuI assisted nucleophilic aromatic exchange reaction. 160 MBq of the radioligand (specific activity 400 Ci/mmol: dose 90 ng/kg) was administered to each subject. Diagnosis of AD was made using the CAMDEX and DSMIIIR criteria with a physical examination, full blood screen, CT and chest X-ray. All subjects were scanned at 21 h post injection on an SME810 emission tomograph. 123I(R,R)QNB activity in the controls was found to be consistent with the known distribution of muscarinic receptors with no activity in the cerebellum and low activity in the thalamus. In the AD patients deficits in 123I-QNB binding which exceeded the corresponding total functional regional perfusion deficit were not found in six of the patients and were observed only in the two most severely affected patients, both of whom were untestable on the cognitive battery.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Improving imaging contributions to trauma and tumor management.

The assessment of patients with injuries and tumors is a major proportion of a neuroradiologist's workload. Reviewing advances in these important topics together in such a short space is a challenge--perhaps even inappropriate. Exciting data emerging from Doppler and xenon computed tomography on head injury, and magnetic resonance gives new insights into spinal trauma, with significant implications for management. Magnetic resonance protagonists pursue their goal of proving greater specificity and sensitivity of diagnosis than computed tomography, with some justification in the case of benign extra-axial tumors. In malignant tumors, data from positron emission tomography emphasize the difficulties of defining tumor extent and hence assessing, let alone achieving, cure.

Brain Damage, Chronic↗
PubMed1993

Abnormalities in rCBF and computed tomography in patients with Alzheimer's disease and in controls.

The pattern of abnormal distribution of the single photon emission computed tomography (SPECT) cerebral blood flow tracer 99m-technetium-hexamethylpropyleneamine oxime (99Tcm-HMPAO) was investigated in 14 patients with clinically diagnosed Alzheimer's disease (AD) who subsequently had post-mortem confirmation of the disease and also in 14 elderly control subjects. These abnormalities were compared with computed tomography (CT) scans to investigate the degree to which the focal SPECT deficits were due to atrophy. The results show that SPECT imaging with 99Tcm-HMPAO and CT scanning both have a higher incidence of abnormality in AD patients than in controls and that the difference between patients and controls is greater with SPECT than with CT. Frontal SPECT and CT abnormalities in moderate/severe Alzheimer's disease occur as frequently as temporal/occipital abnormalities but the latter are rare in control subjects. Around 50% of the SPECT deficits occur in CT normal brain regions, showing that atrophy is not the sole cause of SPECT deficits.

Aged↗
PubMed1992

Neuro-ophthalmic features of carotid cavernous fistulas and their treatment by endoarterial balloon embolisation.

The neuro-ophthalmic features of 11 traumatic carotid cavernous fistulas and their successful occlusion by endoarterial balloon embolisation is reported. Significant improvement in all neuro-ophthalmic signs and symptoms occurred following treatment, however, ocular motility deficits persisted in 7 patients. All 11 fistulas were occluded and the patency of the internal carotid artery was preserved in 9 patients. Though the internal carotid artery was sacrificed in 2 patients there were no permanent sequelae. Transient complications of the procedure occurred in 2 patients.

Adolescent↗
PubMed1992

The prognostic importance of CT features in primary intracranial lymphoma.

The correlation of computerized tomography (CT) features with survival of 28 patients with primary intracranial lymphoma was analysed retrospectively. Severe perifocal oedema, periventricular tumours and lesions which were non-homogenously enhancing or non-enhancing were found to be associated with a poor prognosis. The prognosis when multiple lesions were present was almost the same as that of a solitary lesion (p = 0.95). Ring enhancing lesions had considerably longer survival. Lesions in the frontal region and those close to the meninges, enhancing homogeneously, had a better prognosis.

Adult↗
PubMed1992

Computed tomographic and magnetic resonance imaging classification of head injury.

Neuroimaging with CT and MRI is a basis for decision making in individual head-injured patients and also provides a classification of patients according to severity of damage, patterns of injury, pathophysiologic mechanisms and prognosis. Such classifications can be based on the intracranial lesions identified: subdural, extradural, and intracerebral hematomas, contusions, and shearing lesions, or indirect indications of raised intracranial pressure and brain swelling: shift, obliteration of the third ventricle and basal cisterns, and signs of ischemia. The appropriate classification for early diagnosis and acute decision making may differ from the assessment of severity of damage, prognosis and late sequelae. Parallel systems of classification, suitable for these purposes, are proposed.

Brain Edema↗