The prognostic significance of visible infarction on computed tomography following lacunar stroke: results of a long-term follow-up study.

BACKGROUND AND PURPOSE: Substantial variability in functional outcome and relatively few factors predictive of death or degree of recovery have been observed in patients with lacunar stroke. Such indicators are of great use in the selection of optimal rehabilitation strategies after stroke. Although computed tomography (CT) of patients with a clinical diagnosis of lacunar stroke performed within the first 10 days shows evidence of cerebral infarction in 50% to 60%, the prognostic significance of a visible ischemic lesion on CT is unclear. METHODS: 633 patients who presented with symptoms consistent with lacunar stroke between June 1990 and February 1998 were studied. One hundred fourteen patients imaged with magnetic resonance, 41 patients with nonischemic diagnoses (hemorrhage or tumor), 57 patients imaged within 12 hours of ictus, and 17 patients with incomplete follow-up were excluded from the analysis. The remaining 404 patients were divided into 2 groups, depending on the appearance of the CT scan. Patients with a low-attenuation area on the CT scan consistent with an ischemic lesion in an appropriate region of the brain to explain the presenting symptoms were classified as "CT positive." Patients with either a normal CT scan of the brain or a scan that showed a lesion in an area inconsistent with the presenting symptoms were classified as "CT negative." A series of known or suspected prognostic factors were recorded for each patient: blood pressure, age, smoking, plasma glucose level, serum cholesterol level, and serum triglyceride level. Delay from stroke onset to scanning was also noted. The authors considered 3 outcome measures: survival time, outcome at 6 months after the stroke, and total length of hospital stay for the stroke admission. Six-month outcome was categorized as good (alive at home) or poor (alive in care or dead). RESULTS: There was no difference in survival between the 2 groups (P= .29, log-rank test). After adjusting for other significant prognostic factors (age; relative hazard per additional decade 1.67, P< .0001: plasma glucose level; relative hazard per additional mmol/l 1.08, P= .03) in a proportional hazards model, presence of visible infarction remained nonsignificant (relative hazard 0.84, P= .40). After adjustment for the other significant factor (age, P= .0001), there was no significant difference in 6-month outcome between CT positive and CT negative patients (P= .61). Median total length of hospital stay was not significantly different between the 2 groups (CT positive, 9 days; CT negative, 8 days; Mann-Whitney test, P= .29). CONCLUSION: The authors conclude that in their cohort of patients, having corrected for other prognostic variables, the presence of visible infarction on CT brain scan performed between 12 hours and 30 days of onset of lacunar symptoms is not predictive of duration of hospital stay or of longer term outcome.

Ramipril for hypertension secondary to renal artery stenosis. Changes in blood pressure, the renin-angiotensin system and total and divided renal function.

The converting enzyme inhibitor, ramipril, 20 mg once daily, was given to 3 hypertensive patients with unilateral renovascular disease. At 1 month, 24 hours after the last dose of ramipril, blood pressure, plasma angiotensin II and converting enzyme activity remained low, and active renin and angiotensin I high. There was no tendency for converting enzyme inhibition to be overcome during 1 month of ramipril therapy. Ramipril caused slight increases in serum potassium and urea, no change in serum creatinine and no consistent changes in the renal vein renin ratio. Ramipril caused little change in renal plasma flow on the stenotic side, but filtration fraction was reduced in 2 patients. There was no serious deterioration in total or individual glomerular filtration rate during ramipril therapy. The drug was well tolerated and there were no serious side effects. Ramipril, given once daily, is likely to be effective in controlling hypertension with renal artery stenosis.

A pilot study of streptokinase for acute cerebral infarction.

We evaluated intravenous streptokinase in the treatment of cerebral infarction. Following neurological assessment and cerebral computed tomography (CT), patients aged 40-80 years with symptoms of anterior circulation acute ischaemic stroke were given 1.5 M units streptokinase or saline placebo in a double-blind randomized study. Twenty patients (10 streptokinase, 10 placebo), 11 males, 9 females, aged 57-79 years, were treated out of 512 consecutive admissions to the acute stroke unit over a 2-year period. Initial CT was normal in 11 (6 placebo, 5 streptokinase) and showed early signs of cerebral infarction in nine (4 placebo, 5 streptokinase). Median times from symptom onset to treatment were 5.2 h (placebo) and 5.8 h (streptokinase). Streptokinase treatment was associated with symptomatic hypotension in one patient. Repeat CT at 72 h demonstrated intracerebral haematoma in two patients and haemorrhagic infarction in one patient in the streptokinase group; the two cases of haematoma formation were associated with neurological deterioration and death. One patient in the placebo group had evidence of haemorrhagic infarction at 72 h. There were three deaths in each treatment group, all within the first 14 days. Patients with acute stroke can be evaluated with CT and treated with streptokinase within 6 h, but the opportunity for treatment is currently limited to few patients. Streptokinase treatment is not without risk, but potential clinical benefit justifies ongoing multicentre randomized trials.

Interictal HM-PAO SPECT: a routine investigation in patients with medically intractable complex partial seizures?

Single photon emission computed tomography (SPECT) is increasingly being used as an adjunctive technique in the localisation of epileptogenic foci prior to surgery. As yet, few studies have been undertaken to establish the clinical associations of areas of reduced cerebral perfusion. Sixty-three consecutive patients (15 male, 48 female; median age 30 years, range 14-57 years) with medically intractable complex partial seizures (median/month 8, range 1-36) were investigated as outpatients. All had normal high resolution computerised X-ray tomography (CT) of brain. Twenty-seven (47%) exhibited significant perfusion defects on SPECT scanning with a rotating gamma camera system using Tc-99 HM-PAO. There were no significant differences between patients with normal and abnormal scans in terms of age at scanning or at onset of epilepsy or number of seizures. Patients with perfusion defects did, however, have longer median histories of epilepsy than those with normal scans (normal: 10 years, abnormal: 22 years; P = 0.01). Patients with abnormal scans were no more likely to have suffered febrile convulsions in early childhood. The correlation of abnormal SPECT scans with routine surface EEG recordings was poor with only 41% of cases showing clear agreement between the site of hypoperfusion and focal epileptic activity. It is not yet possible to predict clinically those patients who will exhibit perfusion defects on interictal TC-99 HM-PAO SPECT scanning.

Rectilinear bone scanning: differentiation between metastases and degenerative spinal disease.

Criteria have been developed for radioisotope scanning of bone with an eight-colour-display rectilinear scanner, to differentiate metastases from degenerative spinal disease. If the area of increased uptake is two or more colours "hotter" than normal, this is probably due to metastases even if degenerative spinal disease coexists. The positivity of a scan due to degenerative spinal disease is a function of the degree of sclerosis adjacent to the intervertebral discs and apophyseal joints; it is not related to the degree of osteophyte formation.

The role of spiral computed tomography and D-dimer in pulmonary embolism.

The first part of this study retrospectively compared the discriminatory power of spiral CT versus clinical findings in 112 consecutive patients referred with chest pain or dyspnoea. Spiral CT exhibited a sensitivity 91.9%; specificity 98.7%; PPV 97.1%; NPV 96.1%; accuracy 96.4%. No other test or clinical parameter had acceptable accuracy. The SimpliRED test is a latex method of estimating the level of D-dimer. The second part of this study determined that, in a similar consecutive series of patients referred for lung scintigrams, although SimpliRED tests had a NPV 95.5%, 59/126 (46.8%) consecutive were positive. However on the basis of clinical effectiveness and cost, imaging for suspected pulmonary embolism should be based on a combination of D-dimer estimation and spiral CT.

Vertebral artery dissection diagnosed by non-invasive magnetic resonance imaging.

A forty-year-old man developed right-sided neck discomfort whilst cycling to work. On admission to hospital he was found to have signs of bilateral cerebellar dysfunction. Magnetic resonance imaging of the brain demonstrated bilateral areas of cerebellar infarction. Doppler ultrasound of the vertebral arteries was abnormal and non-invasive gradient echo time of flight magnetic resonance angiography confirmed the clinical diagnosis of vertebral artery dissection. The patient was anticoagulated for a period of three months and made a full recovery.

A simplified approach to the reporting of intensive therapy unit chest radiographs.

The rationale for a simplified approach to the reporting of intensive therapy unit chest radiographs is presented. Pulmonary shadowing should be reported simply as pulmonary shadowing; histological predictions are unreliable and potentially misleading. One should concentrate on the detection of pneumothorax and the differentiation between pulmonary shadowing, pleural effusion and pulmonary collapse.

The radiological diagnosis of analgesic nephropathy.

A study was made of the radiological findings in 57 patients with a clinical diagnosis of analgesic nephropathy. The ages of the patients ranged from 27 to 72 years, and females predominated over males in the ratio 4-7 to 1. Renal failure varied from mild to very severe and the patients showed the usual high incidence of analgesic-induced gastro-intestinal, haematological and neurological disorders. In 82% of cases, kidneys were of normal size, but there was radiological evidence of reduced renal function in 85%. Thus, a small kidney with good renal function was unlikely to be due to analgesic nephropathy. Medullar necrosis was observed in 65%, and papillary atrophy and papillary necrosis each in 46%. Although usually gradual, acute massive sloughing of necrotic papillae could occur and occasionally led to ureteric obstruction. Papillary cavitation was seen in 39% but fistulae and ring shadows were observed in only 11% and 14% respectively, while renal calcification occurred in 26%. With the use of high dose techniques and retrograde pyelography, it is almost always possible to make a positive radiological diagnosis of analgesic nephropathy, even in patients with markedly reduced renal function.

Factors influencing bone scan quality.

A reliable subjective method of assessing bone scan quality is described. A large number of variables which theoretically could influence scan quality were submitted to regression and factor analysis. Obesity, age, sex and abnormality of scan were found to be significant but weak variables.

The pulmonary manifestations of septic shock.

Septic shock carries a high mortality. It is manifest haematologically by thromobocytopaenia and other coagulation disturbances. The radiological manifestations are various degrees of pulmonary oedema, usually affecting the lower zones, without evidence of pulmonary hypertension. Radiological signs are always preceded on accompanied by thrombocytopaenia.

Glue-sniffing as a cause of a positive radio-isotope brain scan.

Convulsions are a known complication of the acute intoxicant effects of solvent abuse. A radio-isotope brain scan done 9 months following status epilepticus secondary to toluene inhalation, in a previously normal school-boy, demonstrated several wedge-shaped areas of increased uptake, in both cerebral hemispheres, consistent with infarcts. It is worth remembering that a positive brain scan in a young person, with recent onset of epilepsy, may be due to glue-sniffing.

The influence of the lordotic projection on the interpretation of the chest radiograph.

The advantages of the lordotic projection, particularly in elucidating suspected pathology at the lung apex, are well known. However, the distortion and artefact of the images of thoracic structures produced by this projection can lead to diagnostic errors. In order to determine the differences in the images produced we compared 14 pairs of lordotic and standard chest radiographs, taken within 24 h of each other, in the same patients. The main artefacts seen in the lordotic views were apparent elevation of the diaphragm, poor visualisation of the lung bases, loss of definition of the aortic knuckle, and apparent widening of the superior mediastinum. These artefacts were greatly exaggerated when lordosis coexisted with pathology, or technical factors such as patient rotation or inadequate respiration. Caution should be exercised to avoid misinterpretation of lordotic films.

The radiology of local complications of haemodialysis access devices.

Of the three types of haemodialysis access devices, radiology is of value in demonstrating local vascular complications only in the arteriovenous graft. The local complications are classified as inflow obstruction, false aneurysm and outflow obstruction. A rational angiographic technique is described and the local complications likely to be encountered are illustrated.

Clinical comparison of three liver scanning agents.

The biological distributions of 99mTc-sulphur colloid, 99mTc-tin colloid and 99mTc phytate colloid were quantitatively compared in a randomised trial. All three radiopharmaceuticals gave satisfactory liver images. There is evidence to suggest that the phytate colloid significantly underestimates splenic uptake. The tin colloid was easier to dispense than the sulphur colloid and was found to be the most suitable radiopharmaceutical.