[Prerequisites, indications and contraindications of IV-lysis of ischemic stroke with rt-PA]

BACKGROUND AND PURPOSE

To evaluate prerequisites, safety, and efficacy of i.v.-thrombolysis of ischemic stroke with rtPA in an academic medical center.

METHODS

Over a period of 2 years and 10 months all patients admitted with a diagnosis of stroke were recruited. Inclusion and exclusion criteria for i.v.-thrombolysis were combined from large scale randomized controlled trials, the time window, however, could be extended up to 4 hours in subjects with a negative CT-scan. Prespecified outcome parameters were the modified Rankin Scale (mRS) and the Barthel Index (BI) at 3 months, and symptomatic hemorrhagic complications. Additionally, time parameters, such as onset-admission-time, door-Ct-time, door-needle time, and onset-needle time were recorded.

RESULTS

During the reported period 103 patients underwent i.v.-thrombolysis, corresponding to 14.9% of all patients with ischemic stroke, and 47% of patients with ischemic stroke arriving in < 3 hours after symptom onset. The mean baseline NIHSS was 14, the mean mRS 13 (3-34), the mean age 70 (+/- 12) years. The following time intervals were observed: Onset-admission-time 64 min., door-CT-time 27 min., admission-needle-time 80 min., and onset-needle-time 142 min. There were 4 symptomatic intracerebral hemorrhagic transformations, including 3 parenchymal hemorrhages, 2 of them lethal, and one with almost full recovery. According to the mRS, 39% of patients had a good (mRS 0-1), 72% a good to moderate recovery (mRS 0-2). The corresponding figures for the BI were 60% BI 95-100 and 72% BI > 90. The mortality was 15%.

CONCLUSION

The i.v.-thrombolysis of ischemic stroke with rt-PA demands appropriate organisation of the pre- and in-hospital phase and can be performed safely and efficaciously in daily clinical routine if inclusion and exclusion criteria as well as all safety measures during the critical phase after therapy are strictly obeyed.

Scattered brain infarct pattern on diffusion-weighted magnetic resonance imaging in patients with acute ischemic stroke

BACKGROUND AND PURPOSE

Infarct patterns on brain imaging contribute to the etiologic classification of ischemic stroke. However, the association of specific subtypes of infarcts and etiologic mechanisms is often weak, and acute lesions are frequently missed on initial computed tomography (CT). Diffusion-weighted imaging (DWI) is superior in visualizing acute ischemic lesions as compared to CT and conventional magnetic resonance imaging (MRI). In our prospective study, we addressed the question whether a distinct pattern of infarction on DWI is associated with infarct etiology and clinical outcome.

METHODS

Sixty-two patients with clinical signs of acute ischemic stroke and negative acute CT upon admission underwent DWI within 10 days after the ictus. Neurological status was documented using the NIH stroke scale. A scattered lesion pattern was defined by at least 2 separate hyperintense DWI lesions within the territory of one of the major cerebral arteries. Ischemic lesions were defined as acute if the region was demarcated strongly hyperintense in all DW images, and if the apparent diffusion coefficient was below normal.

RESULTS

In 32 patients, DWI revealed a scattered lesion pattern, while in 30 patients a single acute lesion was detected. In patients with scattered lesions, potential arterial or cardiac embolic sources were detected in 26 patients (81.3%), as compared to 5 patients (16.6%) in the group with single lesions (chi(2) test, p < 0.0001). The neurological status of patients with scattered lesions improved significantly more than among patients with single lesions (Mann-Whitney test, p < 0.0003).

CONCLUSION

A scattered lesion pattern on DWI in patients with acute brain infarction and negative initial CT scan is associated with an embolic etiology and may indicate a favorable clinical outcome.

Intravenous tPA for ischemic stroke team performance over time, safety, and efficacy in a single-center, 2-year experience

BACKGROUND AND PURPOSE

Safety and efficacy concerns toward thrombolysis for ischemic stroke prevail among many neurologists because of the risks of hemorrhage and the small proportion of suitable patients. We therefore prospectively assessed feasibility, safety, efficacy, and team performance in a single center to prove whether thrombolytic treatment is practical in daily clinical routine.

METHODS

Patients were prospectively recruited over a 2-year period. Major inclusion and exclusion criteria from large, randomized controlled trials were combined. Prespecified outcome parameters were the modified Rankin scale (MRS) and the Barthel Index (BI) at 3 months and symptomatic hemorrhagic complications. In addition, certain time intervals during the diagnostic process preceding thrombolysis were prospectively recorded.

RESULTS

Within 2 years a total of 75 patients underwent intravenous thrombolysis, corresponding to 9.4% of all admitted patients with stroke and 14.9% of patients with ischemic stroke. Mean+/-SD age was 68+/-13 (range 34 to 90) years; median baseline National Institutes of Health Stroke Scale score was 13+/-6 (range 2 to 34). Thrombolysis was started at an average time of 144 minutes after symptom onset, and 13 patients (17.3%) were treated beyond 3 hours. Two cerebral hemorrhages (2.7%) occurred. Outcome according to the MRS was good (MRS 0 to 1) in 40%, moderate (MRS 2 to 3) in 32%, and poor (MRS 4 to 5) in 13%; the corresponding results, as measured by the BI, were 61% (BI 95 to 100, good), 16% (BI 55 to 90, moderate), and 8% (BI 0 to 50, poor). The mortality rate was 15%. Over 2 years the median door-to-CT time decreased from 30 to 22 minutes (27%), and the door-to-needle time was shortened from 96 to 73 minutes (14%). The mean number of patients treated per month increased from 2 to 4.

CONCLUSIONS

Thrombolytic therapy can be performed safely and efficaciously in daily clinical routine. More than a minority of acute stroke patients might be eligible for intravenous thrombolysis. The performance of a stroke team can be improved over time, subsequently increasing the proportion of eligible patients and thereby the efficiency of the method.

Volume-selective proton MR spectroscopy for in-vitro quantification of anticonvulsants

Administration of anticonvulsant drugs is clinically monitored by checking seizure frequency and by determining the serum concentration of the drug. In a few reports, drug concentrations in brain parenchyma have been determined using ex vivo techniques. Little is known about the in vivo concentration in the brain parenchyma. Our goals were to characterise the NMR spectra of the anticonvulsants at therapeutic concentrations, to determine the minimum detectable concentrations, and to quantify the drugs noninvasively. Volume-selective 1H-MR spectroscopy (MRS) was performed under standard clinical conditions using a single-voxel STEAM (stimulated-echo acquisition mode) sequence at 1.5 T. Spectra of the anticonvulsants carbamazepine, phenobarbital, phenytoin and valproate were acquired in vitro in hydrous solutions at increasing dilution. Phenytoin, phenobarbital and valproate were detectable below maximum therapeutic serum concentrations. Within therapeutic ranges, there was good agreement between concentrations determined by 1H-MRS and those by standard fluorescence polarisation immunoassay. Due to the absence of signals of brain metabolites, the aromatic protons of phenobarbital, phenytoin and carbamazepine, with resonance lines around 7.4 ppm, allow the drugs to be detected. Valproate, with two resonances around 1.2 ppm, should be differentiable from potential brain metabolites using nonlinear analysis of the brain spectrum. Volume-selective 1H-MRS is therefore expected to be able to monitor anticonvulsant therapy in vivo.

Transtentorial herniation after unilateral infarction of the anterior cerebral artery

BACKGROUND

Fatal cerebral herniation is a common complication of large ("malignant") middle cerebral artery infarcts but has not been reported in unilateral anterior cerebral artery (ACA) infarction.

CASE DESCRIPTION

We report a 47-year-old woman who developed an acute left hemiparesis during an attack of migraine. Cranial CT (CCT) was normal but demonstrated narrow external cerebrospinal fluid compartments. Transcranial Doppler sonography was compatible with occlusion of the right ACA. Systemic thrombolytic therapy with tissue plasminogen activator was initiated 105 minutes after symptom onset. Follow-up CCT 24 hours after treatment revealed subtotal ACA infarction with hemorrhagic conversion. Two days later, the patient suddenly deteriorated with clinical signs of cerebral herniation, as confirmed by CCT. An extended right hemicraniectomy was immediately performed. Within 6 months, the patient regained her ability to walk but remained moderately disabled.

CONCLUSIONS

This is the first reported case of unilateral ACA infarct leading to almost fatal cerebral herniation. Narrow external cerebrospinal fluid compartments in combination with early reperfusion, hemorrhagic transformation, and additional dysfunction of the blood-brain barrier promoted by tissue plasminogen activator and migraine may have contributed to this unusual course.

Magnetoneurography of evoked compound action currents in human cervical nerve roots

OBJECTIVE

A measurement protocol for magnetoneurography (MNG) is established which allows the non-invasive localization and tracing of evoked compound action currents propagating along cervical nerve roots in man.

METHODS

Inside a magnetically shielded room either both median or both ulnar nerves of healthy subjects were conventionally electrostimulated in alternation. Evoked magnetic responses were recorded using a multichannel SQUID-detector with a planar measuring area centered over the neck. Simultaneously, electric surface potentials were recorded using cervical bipolar electrode montages.

RESULTS

Upon median (ulnar) nerve stimulation somatosensory evoked magnetic fields up to 20 fT (10 fT) amplitude were detected propagating over the cervical transforaminal root entry zone, with corresponding electrical surface potentials of 1.5 microV (0.5 microV). Furthermore, the signal-to-noise ratio of the spatiotemporal magnetic field mappings in median nerve stimulation experiments allowed dipolar source reconstructions and tracing of the propagation of the compound action currents along nerve root fibers.

CONCLUSION

Magnetoneurography allows tracing of the propagation of evoked compound action currents along cervical roots in healthy subjects with millisecond temporal and high spatial resolution. Thus, MNG offers a sensitivity appropriate to serve as a clinical diagnostic tool for localizing focal neuropathies of cervical nerve roots.

Effects of continuous estrogen and estrogen-progestin replacement regimens on cardiovascular risk markers in postmenopausal women

OBJECTIVE

To evaluate the influence of 2 continuous combined estrogen-progestin replacement products, compared with unopposed estrogen and placebo, on cardiovascular risk markers in postmenopausal women in a randomized, double-blind, placebo-controlled trial.

METHODS

Two hundred seventy healthy postmenopausal women were randomly assigned to 1 of 4 treatment groups: placebo, unopposed 17-beta estradiol (1 mg), 1 mg of 17-beta estradiol with 0.25 mg of norethindrone acetate, or 1 mg of 17-beta estradiol with 0.5 mg of norethindrone acetate. The primary outcome variable was change from baseline in low-density lipoprotein cholesterol concentration. Additional outcome variables included changes in other serum lipid levels, hemostatic variables, and indicators of carbohydrate metabolism.

RESULTS

The low-density lipoprotein cholesterol level was reduced to a similar degree in all groups receiving active treatment (10%-14% from baseline; P =.001 for 17-beta estradiol with 0.5 mg of norethindrone acetate, P =.004 for 17-beta estradiol with 0.25 mg of norethindrone acetate, and P =. 001 for 1 mg of 17-beta estradiol vs placebo). Compared with unopposed 17-beta estradiol, 17-beta estradiol with 0.5 mg of norethindrone acetate enhanced the reductions in total cholesterol and apolipoprotein B levels (P<.01 vs 17-beta estradiol). 17-beta Estradiol plus norethindrone blunted or reversed the increases in levels of high-density lipoprotein cholesterol, apolipoprotein A-I, and triglycerides produced by 17-beta estradiol alone. Effects of 17-beta estradiol plus norethindrone on hemostatic variables were similar to those of 17-beta estradiol except for factor VII activity, which was significantly reduced with 17-beta estradiol combined with 0.25 mg (P<.01) and 0.5 mg (P<.05) of norethindrone acetate. 17-beta Estradiol plus norethindrone appeared to blunt reductions in C-peptide and insulin levels produced by unopposed 17-beta estradiol but did not elevate these values compared with placebo.

CONCLUSIONS

17-beta Estradiol plus norethindrone produced favorable changes in most cardiovascular risk markers evaluated and has a profile distinct from that of unopposed 17-beta estradiol. The impact of these differences on cardiovascular events warrants investigation. Arch Intern Med. 2000;160:3315-3325.

Acute bilateral arm paresis

OBJECTIVE

To study pure motor bilateral arm paresis of acute onset. This syndrome is as yet a barely described clinical feature attributed to ischemia in the territory of the anterior spinal artery (ASA).

CASES

We present 2 patients with acute onset of pure motor deficit in both upper extremities.

RESULTS

Magnetic resonance imaging of the cervical spinal cord revealed infarcts in the territory of the ASA. In 1 case, electrophysiology further suggested discrete gray matter involvement.

CONCLUSION

In patients with acute weakness of both arms without further neurological deficits, an incomplete ASA syndrome should be considered with the anterior horns predominantly being affected. Magnetic resonance imaging and electrophysiology are valuable tools to further confirm both location and extension of the spinal lesion.

Association between elevated plasma fibrinogen and the small, dense low-density lipoprotein phenotype among postmenopausal women

A predominance of small, dense low-density lipoprotein (LDL) particles (subclass pattern B) has been associated with a 2- to threefold increase in coronary heart disease risk. Recently, it has been reported that LDL subclass pattern B is associated with hyperfibrinogenemia, which is also a coronary heart disease risk factor. The present study examined the relation between hyperfibrinogenemia and LDL subclass pattern in 258 postmenopausal women. A significant univariate correlation was observed between the concentration of cholesterol carried in small, dense LDL particles and plasma fibrinogen concentration (r = 0.17, p = 0.01). The prevalence of LDL subclass pattern B was 41.9% in the highest fibrinogen tertile, compared with 27.9% and 24.4% in the first and second tertiles, respectively (global chi-square 6.8, p = 0.03). The crude odds ratio (OR) for LDL subclass pattern B among women in the highest fibrinogen tertile, compared with the lower tertiles, was 2.03 (95% confidence interval [CI] 1.18 to 3.51, p = 0.01). After adjustment for age and plasma lipids (log(e) triglycerides, LDL cholesterol, and high-density lipoprotein cholesterol), the OR was 2.14 (95% CI 1.17 to 3.96, p = 0.01). Further adjustment for hematocrit, indicators of carbohydrate homeostasis, body mass index, waist circumference, and several variables related to lifestyle did not attenuate this association (OR 2.56, 95% CI 1.27 to 5.27, p = 0.01). These data suggest that hyperfibrinogenemia and LDL subclass pattern B may be 2 components of a common syndrome and suggest that hyperfibrinogenemia may contribute to the increased coronary heart disease risk associated with LDL subclass pattern B.

Low-density lipoprotein subclass distribution pattern and adiposity-associated dyslipidemia in postmenopausal women

OBJECTIVE

A predominance of small, dense low-density lipoprotein (LDL) particles (subclass pattern B) is associated with increased risk for coronary heart disease and is characterized by elevated triglycerides and depressed high-density lipoprotein (HDL) cholesterol concentrations. The present analysis was undertaken to assess the impact of LDL subclass distribution pattern and adiposity on serum lipids in postmenopausal women.

METHODS

Anthropometric measurements and fasting lipid data were obtained from 254 postmenopausal women 70 years of age or younger, not receiving sex hormone replacement, who were participating in a clinical trial designed to assess the influence of hormone replacement regimens on coronary heart disease risk markers.

RESULTS

The prevalence of LDL subclass pattern B was 32%. Triglyceride levels were higher and HDL cholesterol lower (both p<0.001) in women with pattern B vs. pattern A, but total and LDL cholesterol levels did not differ. LDL subclass pattern contributed independently to the variance in HDL cholesterol (p<0.001) and log(e) triglyceride (p<0.001) concentrations explained by anthropometric variables (waist circumference or body mass index). Compared to women with LDL subclass pattern A and waist circumference below the median value of 83.0 centimeters, those with pattern B and waist > or =83.0 centimeters had markedly lower HDL cholesterol levels [44.0 (41.6-47.4) vs. 57.2 (54.1-60.3) mg/dL, mean (95% CI)] and increased triglyceride concentrations [geometric mean 147.8 (131.6-165.7) vs. 95.4 (88.2-102.5) mg/dL].

CONCLUSIONS

These data suggest that adiposity and LDL subclass distribution pattern are independent determinants of plasma triglyceride and HDL cholesterol concentrations in postmenopausal women.

Interrater agreement for high grade carotid artery stenosis measurement and treatment decision

OBJECTIVES

Randomized trials in North America (NASCET, ACAS) and Europe (ECST) have shown a beneficial effect of endarterectomy for patients with high grade carotid artery stenosis. The results of the NASCET and the ECST further suggest that the effect of endarterectomy differed by degree of stenosis, supporting the importance of stenosis measurement as a factor in the decision process regarding surgery. We investigated the interrater agreement for carotid artery stenosis measurements and treatment decision in a post hoc study on patients undergoing carotid surgery.

METHODS

In a one-year series, 45 consecutive patients underwent preoperative conventional cerebral angiography followed by endarterectomy. Using a magnifying eyepiece and applying the two different measurement criteria of the randomized trials, angiograms were re-evaluated post hoc by three masked raters. Intra-class correlation coefficients (ICCs) with one-sided 95% confidence intervals (CIs) were calculated for the estimation of interrater agreement for degree of stenosis. Conger s kappa (k) statistics were used for the estimation of interrater agreement for a dichotomized stenosis evaluation, i.e. therapeutic decision on surgery (cut-off point for symptomatic stenosis: 70%, cut-off point for asymptomatic stenosis: 60%).

RESULTS

ICCs were.74 (CI.63) for NASCET/ACAS criteria and.72 (CI. 59) for ECST criteria. k values were.55 (CI.42) for NASCET/ACAS criteria and.57 (CI.44) for ECST criteria. Disagreement for a therapeutic decision was seen in 6 of 23 symptomatic patients by NASCET criteria, in 2 of 23 symptomatic patients by ECST and in 4 of 22 asymptomatic patients by ACAS criteria.

CONCLUSIONS

Overall, the interrater agreement for stenosis measurements was good. Agreement for therapeutic decisions on carotid surgery, however, was less strong. These findings suggest that accurate stenosis measurement may not suffice for reliable treatment decisions in patients with high grade carotid artery stenosis.

Predictive value of clinical lacunar syndromes for lacunar infarcts on magnetic resonance brain imaging

OBJECTIVE

We prospectively investigated the predictive value of clinical and CT-supported lacunar syndromes for lacunar infarcts on magnetic resonance (MR) brain imaging.

PATIENTS AND METHODS

The 54 prospective, consecutive patients had clinical lacunar syndromes of acute onset and early computed tomography (CT; on admission day, i.e. < or =48 h after onset of symptoms) showing either a small deep infarct or no corresponding lesion. Taking MR (at day 2 to 4 after admission) as the gold standard, the positive predictive value of the CT-supported clinical syndrome for corresponding lacunar lesions was calculated.

RESULTS

In 27 (50%) patients, early CT showed a lacunar infarct corresponding to the clinical syndrome, a further 27 (50%) patients had no fresh ischemic lesion. In 51 patients (94%), MR showed a recent lacunar infarct (hyperintense lacune in T2-weighted scans, no demarcation on T1-weighted scans and/or positive gadolinium-enhancement) corresponding to the clinical syndrome (positive predictive value 0.94, 95%, CI: 0.88 to 0.98). In 3 (6%) patients MR was normal. Aside from old unrelated ischemic (macro- and/or microangiopathic) lesions, MR revealed no acute non-lacunar infarct. CT and MR sites of lacunar lesions were matching. Compared to gold standard MR, the sensitivity of early CT for suspected lacunar lesions was 0.53 (95% CI: 0.38 to 0.67).

CONCLUSION

Lacunar syndromes were highly predictive for small deep infarcts on MR. Magnetic resonance brain imaging may be redundant in the setting of a lacunar syndrome supported by a CT that excludes non-ischemic causes of stroke; it may therefore be abandoned in order to reduce costs in the health care system.

Presentation and prognosis of bilateral infarcts in the territory of the superior cerebellar artery

Unilateral cerebellar infarcts in the territory of the superior cerebellar artery (SCA) have been studied in recent years to delineate the clinical presentation and stroke mechanism, but most studies excluded bilateral infarctions. We have studied patients with bilateral SCA infarctions to provide data on clinical findings, stroke distribution and outcome. We collected data of 8 patients with bilateral SCA infarctions recognized by computed tomography and/or magnetic resonance imaging. The most common clinical presentation of patients with bilateral SCA infarctions were nausea, vomiting or vertigo (6 patients), often associated with ataxia and dysarthria (5 patients). Further symptoms were variable and depended on additional infarcts in other vascular territories. Infarcts were often partial or scattered with equal distribution between the medial and lateral branches of the SCA. Complete infarction within the SCA area occurred in less than half of the cases. Clinical outcome was either benign (full recovery in 3 patients) or fatal (5 patients). Predictors for a good clinical recovery were young age, few vascular risk factors, only partial involvement of the SCA territory without involvement of other vascular territories, and absent limb weakness on clinical presentation.

Non-invasive long-term recordings of cortical 'direct current' (DC-) activity in humans using magnetoencephalography

Recently, biomagnetic fields below 0.1 Hz arising from nerve or muscle injury currents have been measured non-invasively using superconducting quantum interference devices (SQUIDs). Here we report first long-term recordings of cortical direct current (DC) fields in humans based on a horizontal modulation (0.4 Hz) of the body and, respectively, head position beneath the sensor array: near-DC fields with amplitudes between 90 and 540 fT were detected in 5/5 subjects over the auditory cortex throughout prolonged stimulation periods (here: 30 s) during which subjects were listening to concert music. These results prove the feasibility to record non-invasively low amplitude near-DC magnetic fields of the human brain and open the perspective for studies on DC-phenomena in stroke, such as anoxic depolarization or periinfarct depolarization, and in migraine patients.

[The practice of medicine at the end of the Second Empire: according to a book, appearing in 1865, by Dr. Camille Delvaille, physician in Bayonne]

Dr Camille Delvaille (1835-1904) was a physician in Bayonne. He wrote many books about scientific problems and social medicine; he was one of the first to suggest medical control at school. In a book, written in 1865, he studied everyday practice in France. He complained against the "Officiers de Sante" who exercised medicine mainly in the countryside but were not doctors and had followed very short medical studies. Dr Delvaille deplored that it meant two kinds of cares: doctors for top people and Officiers de Sante for poor patients. In fact, the end of the Officiat de Sante occured only in 1892. Dr Delvaille studied also some problems related to medical demography; he purposed for our country a law cutting down foreign practice in France. Then, he put forward nomination of Professors or hospital's physicians through an examination instead of routine cooptation. Some of his minds are ahead and were applied later.

Heparin-mediated extracorporeal LDL/fibrinogen precipitation--H.E.L.P.--in coronary and cerebral ischemia

Cerebral and myocardial infarctions share common aspects of pathobiochemistry. The central problem is the oxygen supply of the infarcted region. To maintain this supply, H.E.L.P.-apheresis (Heparin-mediated Extracorporeal LDL/Fibrinogen Precipitation) has already proven beneficial in the prevention and therapy of myocardial infarction. Since H.E.L.P.-apheresis can lower significantly plasma viscosity and erythrocyte aggregation without reducing the oxygen transport capacity, patients with cerebral infarction (stroke) may also benefit from our experiences in myocardial ischemia. The system is designed to remove selectively plasma fibrinogen, LDL-cholesterol and lipoprotein(a) from blood circulation, simultaneously. The removal of the plasma compounds is achieved by extracorporeal precipitation with heparin at low pH. Excess heparin is completely removed by an adsorber before the plasma is given back to the patient. H.E.L.P.-apheresis has proved to be safe in patients with coronary heart disease and allows a controlled reduction of thrombogenic plasma compounds. It is therefore hoped to be effective also in patients with acute ischemic stroke.

Prospective study on the complication rate of carotid surgery

BACKGROUND

Randomized trials of carotid endarterectomy for high-grade stenosis have shown a benefit for surgery under the condition of low perioperative complication rates. Concerns have been expressed that the complication rates of carotid surgery are higher in everyday practice and may vary considerably between centers. We prospectively established the complication rate for carotid surgery in a single institution.

DESIGN

Prospective 2-year study. All patients received pre- and postoperative neurological evaluation. Laboratory tests included pre- and postoperative brain imaging, intracranial and neck vessel sonography, conventional angiography, magnetic resonance angiography, and intraoperative monitoring.

PARTICIPANTS

108 consecutive patients: 54 symptomatic patients fulfilling the inclusion criteria of the European Carotid Surgery Trial (ECST) and 54 asymptomatic patients fulfilling the inclusion criteria of the North American Trial on Asymptomatic Stenoses (ACAS).

SETTING

Single academic center with a high volume of carotid endarterectomies (>50 per year). Participating center in ECST.

MAIN OUTCOME MEASURES

Stroke or death as defined in the randomized trials.

RESULTS

The overall complication rate was 8.3% (95% CI 4.1-15.6%). Complications were more frequent in patients with symptomatic stenosis (11.1%, CI 4.6-23.3%) than in asymptomatic cases (5.6%, CI 1.5-16.4%). Three patients died (2 strokes, 1 myocardial infarction). Disabling strokes were found in 2 patients (Rankin scale scores 3 and 4). Nondisabling strokes (Rankin scale score 1 and 2) occurred in 4 patients. The complication rates for symptomatic and asymptomatic patients were higher than the ones reported in the randomized trials, but 95% confidence intervals showed that the differences were not statistically significant. The point estimates of complication rates still supported a benefit of surgery for patients with symptomatic stenosis, but denied a positive effect of endarterectomy for patients with asymptomatic stenosis.

CONCLUSION

In this center, a beneficial effect of carotid surgery for asymptomatic stenoses cannot be safely assumed.

Callosal disconnection syndrome in a left-handed patient due to infarction of the total length of the corpus callosum

We report on a left-handed patient with an ischemic infarction affecting exclusively the total length of the corpus callosum. This lesion clinically correlated with an almost complete callosal disconnection syndrome as described in callosotomy subjects, including unilateral verbal anosmia, hemialexia, unilateral ideomotor apraxia, unilateral agraphia, unilateral tactile anomia, unilateral constructional apraxia, lack of somesthetic transfer and dissociative phenomena. Despite the patient's left-handedness, his pattern of deficits was similar to the disconnection syndrome found in right-handers. Our report focusses on motor dominance and praxis. We followed-up the improvement in left apraxia and investigated the ability to initiate and learn a new visuo-motor skill. The results permit two tentative assumptions: (1) that the improvement in left apraxia was due to a compensatory increase in ipsilateral proximal muscle control, and (2) that motor dominance, i.e. the competence to initiate and learn a new movement pattern, was hemispherically dissociable from manual dominance in the sense of praxis control.

Comparison of restimulation methods to elicit SIV specific cytotoxic T-lymphocytes (CTL) in vitro: Staphylococcal enterotoxin B (SEB) provides a novel method for the quantification of SIV specific CTL precursors

Most investigators believe that an effective HIV-1 vaccine will have to induce high levels of HIV-1 specific cytotoxic T-cells (CTL). The macaque SIV challenge/protection model system has been used to test candidate vaccines, but quantitative immunogenicity measurements are difficult due to technical limitations of the assays available. The quantification of SIV specific CTLp is crucial to understanding correlates of immunity for these vaccines, but are difficult to measure. We have compared various methods to quantify SIV specific CTLp, and describe a novel method of SIV specific CTL in vitro stimulation using the superantigen Staphylococcal enterotoxin B (SEB). SEB can stimulate high levels of CTLp in vitro, and provides an alternative method to induce SIV specific CTL.