Interleukin-2, its soluble receptor,and soluble T8 antigen in acute ischemic stroke

The treatment of neoplasia with interleukin-2 (IL-2) can be complicated by neurological deficits resembling transient Ischemic attack and stroke. We investigated whether interleukin-2 contributes to the natural course of cerebrovascular ischemia and particularly to the pathogenesis of infection-associated stroke. Plasma levels of interleukin-2 were below the level of detectability in almost all measurements. Patients with and without previous infection (n = 11, 805 ±445 U/ml vs n = 19, 824 ± 501 U/ml) did not have significantly higher levels of soluble interleukin-2 receptors than control subjects with (n = 14, 667 ± 229 U/ml) or without vascular risk factors (n = 17, 567 ± 176 U/ml). Receptor levels increased in patients during the first week after stroke (n = 15, 1157 ± 1013, p < 0.02). Levels of soluble T8 antigen (sT8) were higher in patients (n – 26, 320 ± 112 U/ml) than in healthy control subjects (n = 15, 246 ± 92 U/ml; p < 0.05) and sT8 levels increased during the first week after stroke (p < 0.05). These results reflect an immunological response to the cerebral infarct; they do not indicate a general role of the IL-2 system in the pathogenesis of ischemic stroke with or without previous infection.     

Residual Flow Signals Predict Complete Recanalization in Stroke Patients Treated With TPA

BACKGROUND: Residual blood flow around thrombus prior to treatment predicts success of coronary thrombolysis. The authors aimed to correlate the presence of residual flow signals in the middle cerebral artery (MCA) with completeness of recanalization after intravenous tissue plasminogen activator (TPA). METHODS: The authors studied consecutive patients treated with intravenous TPA therapy who had a proximal MCA occlusion on pretreatment transcranial Doppler (TCD). Patients were continuously monitored for 2 hours after TPA bolus. Absent residual flow signals correspond to the thrombolysis in brain ischemia (TIBI) 0 grade, and the presence of residual flow signals was determined as TIBI 1-3 flow grades. Complete recanalization was defined as flow improvement to TIBI grades 4-5. RESULTS: Seventy-five patients with a proximal MCA occlusion had median pre-bolus NIHSS 16 (85% with > or = 10 points). TPA bolus was given at 141 +/- 56 minutes (median 120 minutes). Complete recanalization was observed in 25 (33%), partial in 23 (31%), and no early recanalization was seen in 27 (36%) patients within 2 hours after TPA bolus. Only 19% with absent residual flow signals (TIBI grade 0, n = 26) on pretreatment TCD had complete early recanalization. If pretreatment TCD showed the presence of any residual flow (TIBI 1-3, n = 49), 41% had complete recanalization within 2 hours of TPA bolus (P = .03). CONCLUSIONS: Patients with detectable residual flow signals before IV TPA bolus are twice as likely to have early complete recanalization. Those with no detectable residual flow signals have less than 20% chance for complete early recanalization with intravenous TPA and may be candidates for intra-arterial therapies.     

The validity of a simple clinical classification of acute ischaemic stroke

The aim of the study reported here was to test the validity of a simple clinical classification of acute ischaemic stroke (Oxfordshire Community Stroke Project, OCSP) in predicting the site and size of cerebral infarction on computed tomography (CT). Consecutive patients admitted to hospital with acute ischaemic stroke were prospectively identified and classified into one of four clinical syndromes according to the OCSP classification, blind to the result of CT. The CT brain scans were classified blind to the clinical features into those demonstrating: small, medium or large cortical infarcts; small or large subcortical infarcts in the anterior circulation territory; and posterior cerebral circulation territory infarcts. A total of 108 patients were included. A recent infarct was seen. on the CT scan in 91 patients (84%), and the clinical classification correctly predicted the site and size of the cerebral infarct in 80 of these (88%; 95% confidence interval 77–92%). The positive predictive value was best for large cortical infarcts (0.94) and worst for small subcortical infarcts (0.63). The OCSP clinical classification is a reasonably valid way of predicting the site and size of cerebral infarction on CT and can, therefore, be used very early after stroke onset before the infarct appears on the scan.     

The management of arteriovenous malformations in children

Between January 1941 and June 1989, 46 children below the age of 18 with an arteriovenous malformation (AVM) were managed. There were 7 patients with AVM diagnosed before the age of 2; 10 patients were diagnosed between the ages of 3 and 10; and 29 patients were diagnosed between 11 and 18. There were equal numbers of male and female patients. Twenty-five of the AVMs were large (>5 cm longest diameter). All 7 AVMs diagnosed before the age of 2 were large. The usual clinical presentation was congestive heart failure, bruit and an enlarging head. Three patients underwent excision with 2 deaths and 1 excellent result. In 11 patients (aged 3–18) with AVM without history of hemorrhage, 3 had excision with 2 excellent and 1 fair result. Four remained stable. Four developed progressive deficits or hemorrhage. In 10 patients (aged 3–18) with AVM and hemorrhage who were treated medically, 7 (70%) had an episode of re-hemorrhage. Three patients had excision of AVM after re-hemorrhage, but before the age of 18 with an excellent result. Eighteen patients (aged 3–18) with AVM and a single episode of hemorrhage underwent excision with 17 excellent or good results and 1 fair result. The overall mortality was 7%. Eighty-five percent of the children with excision of AVM had an excellent or good result. The best treatment for AVM in children is surgical excision.Presented at the XVII Annual Meeting of the International Society for Pediatric Neurosurgery, Bombay 1989     

Kinetics of cardiorespiratory response to dynamic and rhythmic — static exercise in men

Summary Kinetics of cardiorespiratory response to dynamic (DE) and then to rhythmic-static exercise (RSE) was compared in nine male subjects exercising in an upright position on a cycle ergometer at an intensity of about 50 % O_2max and a mean pedalling frequency of 60 rpm over 5 min. Respiratory frequency (f _R), tidal volume (V _T), minute ventilation ( _E), heart rate (f _c), stroke volume (SV), and cardiac output (Q _t) were measured continuously. The RSE caused a greater increase in f _R than DE, whereas V _T increased more during DE. The effect of reciprocal changes in f _R and V _T was that _E and its kinetics, expressed as a time constant (), did not differ between experimental situations. The ventilatory equivalent for O₂ ( _E: O₂) was greater for RSE (31.3) than for DE (23.0, P<0.01). Elevation of f _c was similar for both types of exercise. The SV increased suddenly at the beginning of DE from 54 ml to 74 ml and then decreased to the end of exercise. At the onset of RSE only a moderate increase in SV was observed, from 56 ml to 62 ml, and then SV remained stable. The DE caused a greater and faster increase in Q _t (4.20 l · min^–1, for equal to 16.1s) than RSE (3.25 l · min^–1, for equal to 57.0s, P<0.05 and P<0.002, respectively). Total peripheral resistance was almost 40% greater for RSE than for DE. No relationship was found between Q _t and V_E at the first 15 s of both types of exercise. It is concluded that the kinetics of _E did not depend on to kinetics of Q _t in the exercising subjects. This finding contradicts the hypothesis of cardiodynamic hyperpnoea indicating an importance of neurogenic factors, mediated either centrally or peripherally, in fast cardiorespiratory responses to exercise.     

Cation-osmotic haemolysis in stroke patients

Erythrocyte microrheology changes were measured by cation-osmotic haemolysis (COH) in healthy donors, patients with ischameic stroke, and patients who died within four days after a stroke. COH in patients with stroke was significantly decreased in comparison with that from healthy donors. In patients who died, COH was significantly decreased compared to patients who survived. The relationship between cationosmotic haemolysis and erythrocyte deformability is discussed.     

Movement related potentials in acutely induced weakness and stroke

Weakness is a common symptom of neurological illness, and recovery may occur via restorative or compensatory mechanisms. Functional imaging studies have shown varied patterns of activity in motor areas following recovery from stroke. Movement related potentials (MRP) reflect the activity in primary and non-primary motor areas. We recorded MRPs in association with index finger abduction in six normal volunteers before and after induced weakness of a hand muscle and in six stroke patients with subcortical lesions and weakness affecting the arm. In both groups of subjects the greatest change was observed in the motor potential component of the MRP. On average, the motor potential had its greatest amplitude and duration at the time of the greatest weakness and became smaller with recovery. In artificially-induced weakness, the MRP had an earlier onset latency (P=0.042) and a greater early BP component (P=0.05) for the weakened finger. For the stroke subjects overall, the peak and NS amplitudes were largest for the initial study and declined thereafter. Similar but smaller changes were present for movements of the clinically unaffected side. The increased motor potential is therefore consistent with increased activity in the motor cortex, and this may occur as compensation for weakness in both normals and after stroke.     

Alcohol and obesity: A new look at high blood pressure and stroke

Summary An investigation of the staff of a car assembly plant (3,351 persons) revealed a similarity between the change in relative body weight and diastolic blood pressure with age. There is a good temporal correlation between the course of alcohol consumption during life and the change of the relative body weight. German women had significantly less blood pressure for the same relative body weight than German men, and foreign employees had lower blood pressure than Germans In both cases the main cause is the difference in alcohol consumption. Besides obesity and hereditary factors, alcohol is the main cause of essential hypertension today. Epidemiological and experimental data indicate that there are two ways from alcohol to high blood pressure, a more direct one and an indirect one via obesity. Alcohol causes obesity via a change in metabolism (hyperinsulinism) rather than by higher caloric intake. In both ways alcohol is an important cause of stroke. To reduce body weight and blood pressure, a reduction of alcohol consumption should be recommended in addition to reduced caloric intake and increased physical activity as means of preventive neurology.