Systematic review and meta-analysis of the effect of pertussis vaccine in pregnancy on the risk of chorioamnionitis, non-pertussis infectious diseases and other adverse pregnancy outcomes

BACKGROUND

Several countries have introduced maternal immunisation with pertussis vaccine to provide protection against pertussis in early infancy. There is increasing interest in non-specific effects of vaccines including that non-live vaccines may enhance susceptibility to non-targeted infections in females. Some studies have shown increased risk of chorioamnionitis among women receiving pertussis vaccine during pregnancy. We aimed to conduct a systematic review and meta-analysis of the effect of maternal pertussis immunisation on the risk of chorioamnionitis, as well as the secondary outcomes of non-pertussis infections in women, non-pertussis infections in infants, spontaneous abortion or stillbirth, maternal death and infant death.

METHODS

We searched PubMed and Embase for articles published until January 14, 2021. We screened articles for eligibility and extracted data using Covidence. Quality was assessed using Cochrane RoB tool and Newcastle-Ottawa Scale. Data were imported into RevMan for pooling and conduction of a meta-analysis stratified by study type. Outcomes are presented as risk ratios.

RESULTS

We identified 13 observational studies and six randomized controlled trials eligible for inclusion. We pooled data on chorioamnionitis from six observational studies and found maternal pertussis vaccine (mostly compared with other maternal immunizations with non-live vaccines) to be associated with an increased risk among the pertussis vaccinated women, RR = 1.27 [CI 95%: 1.14-1.42]. We found no difference in the analysis of our secondary outcomes of non-pertussis infections, spontaneous abortion or stillbirth and death.

CONCLUSION

We found an increased risk of chorioamnionitis among women who received pertussis vaccine in pregnancy. The large number of women receiving pertussis vaccine during pregnancy, as well as the growing evidence of non-live vaccines causing increased susceptibility to infections, indicates a need for further randomised trials to assess potential adverse effects of maternal immunisation with pertussis-containing vaccines.

Home readings of blood pressure in assessment of hypertensive subjects

Out-patient clinic blood pressure (OPC-BP) was compared to home blood pressure (Home-BP) measured three times daily during a two week period in 122 consecutively referred hypertensive subjects. A semi-automatic device (TM-101) including a microphone for detection of Korotkoff-sounds, self-deflation of cuff pressure and digital display of blood pressure was used. Mean difference between OPC-BP and Home-BP was systolic +13 mm Hg (range -21 - +100 mg Hg) and diastolic +5 mm Hg (range -27 - +36 mm Hg). Although a significant correlation could be demonstrated between Home-BP and OPC-BP, the inter-individual scatter was pronounced and unpredictable from the hypertensive organ damages. It is argued, that home readings should be used to greater extent in the evaluation of patients with hypertension.

Smoking habits and prevalence of clinical diabetic microangiopathy in insulin-dependent diabetics

All patients having insulin-dependent diabetes with onset before 30 years of age and a duration of disease of 12-40 years who visited a diabetes centre within one year were registered. 97% (n = 668) answered a WHO questionnaire on cigarette smoking. The smoking habits were compared to the frequency of proliferative retinopathy and/or diabetic nephropathy (persistent proteinuria). The prevalence of diabetic nephropathy was significantly higher among heavy smokers (greater than 10 cigarettes a day for more than one year) than among non-heavy smokers, 19.2% versus 12.1% (p less than 0.02). An increasing frequency of nephropathy was found with increasing cigarette consumption (p less than 0.01). No difference in the prevalence of proliferative retinopathy was found between smokers and non-smokers. It is concluded that cigarette smoking is a risk factor for the development of nephropathy in insulin-dependent diabetics.

24-hour blood glucose profiles in insulin-dependent diabetics treated with intravenous insulin infusion systems. A comparison between closed- and open-loop systems

The aim of this study was to compare the 24-hour blood glucose profiles of insulin-dependent diabetics during treatment with preprogramed insulin delivery systems with those of patients on treatment with the artificial beta cell (Biostator). Mean blood glucose (MGB) was 4.4 +/- 0.5 mmol/l for 15 controls, 5.8 +/- 1.0 for 53 patients on open-loop and 6.0 +/- 0.6 for 20 patients on closed-loop treatment. MBG was significantly higher in diabetics than in non-diabetic, but the difference between the two diabetic populations was not significant. Mean amplitude of blood glucose excursion was 1.8 +/- 0.6, 4.3 +/- 1.3 and 3.5 +/- 0.8 mmol/l respectively, the difference between the diabetic groups being significant. No hypoglycemia was seen in patients during closed-loop treatment, whereas this was the case in 10 of 53 patients on treatment with open-loop systems. Physical exercise resulted in small but normal decreases in blood glucose without hypoglycemia. Plasma insulin was within the normal range during both regimes. It is concluded that blood glucose control during treatment with closed-loop system is superior to that during treatment with open-loop systems. However, under standard conditions i.v. insulin infusion with preprogramed pump devices resulted in blood glucose fluctuations comparable with those during Biostator treatment.

Prognosis for juvenile diabetics with nephropathy and failing renal function

A total of 157 consecutive patients with juvenile diabetes (onset before the 31st birthday), diabetic nephropathy, and impaired renal function were followed up until 1.1.1976. All the patients had been admitted to the Steno Memorial Hospital, Copenhagen, between 1934 and 1972. Independently of the patients' age at onset of diabetes, it was found that persistent proteinuria appeared after an average of 19 years, and that death ensued 5--6 years thereafter. Division of the patients into two groups, according to whether the diabetes had set in before or after 1940, showed no signs of an improved prognosis during the past few decades. Once the serum creatinine has started to rise, the prognosis is very grave. Only 50% were alive 21 months after serum creatinine levels of 2--5 mg/100 ml had been ascertained. Among patients whose serum creatinine exceeded 5 mg/100 ml, 50% succumbed in 9 months. It is concluded that renal transplantation, if it is to be done, should be instituted early.

Trends in symptoms of obstructive lung disease in Norway

SETTING

Evidence is accumulating that there has been an increase in the adult population burden of obstructive lung disease. Has this increased the burden of symptoms? It is possible that diagnostic efficiency has improved, so that milder asthma cases are being diagnosed.

OBJECTIVE

To investigate changes in symptom burden by asthma diagnosis, age and sex.

DESIGN

We performed two postal cross-sectional studies among adults aged 15-70 years in Oslo, Norway, in 1972 and again in 1998/1999 (total = 39998). Changes in 11 self-reported respiratory symptoms were investigated.

RESULTS

The prevalence of having at least one symptom increased from 50% to 60% (P < 0.001), and the distribution of symptoms showed an overall increase. Nine symptoms increased in prevalence. The increase was largest among the young and females, and was present in both those with and those without asthma. For any given number of reported symptoms, asthma prevalence was higher in 1998 than in 1972, suggesting increased case finding.

CONCLUSION

There has been an increase in the population burden of respiratory symptoms matching the observed increase in young adult asthma, together with a probable increase in the clinical willingness to give an asthma diagnosis.

[Clinical value of SPECT scanning in children with neurological disorders]

We retrospectively evaluated the clinical value of Tc-99-HMPAO brain single photon emission tomography (SPECT) in 21 children with neurological disorders of varied aetiology. All 21 patients were examined with electroencephalograms (EEGs), 17 with computed tomography (CT) and ten with magnetic resonance imaging (MR). New relevant information was obtained from SPECT in all 21 cases and in four of these cases the investigation directly led to a change in diagnosis and better assessment of the prognosis. It is concluded that SPECT is an important investigational method in children with neurological symptoms of partly or completely unknown aetiology.

Interictal SPECT of rCBF is of clinical utility in the preoperative evaluation of patients with partial epilepsy

Fifty-eight patients with drug-resistant partial epilepsy were studied preoperatively by interictal rCBF measurements using 99mTc-HMPAO and a dedicated brain SPECT camera (Tomomatic 64). Follow-up of seizure outcome, using the "Engel score", was at least 3 years. The data were analyzed in a blinded set-up, first visually and subsequently quantitatively by an automatic regional analysis. By visual analysis 95% of the patients were considered abnormal in one part of the brain, of whom 27% were abnormal on CT, 45% on MRI and 98% on scalp EEG. Using a quantitative regional analysis subdividing each hemisphere into 17 larger regions, 85% of the patients had an abnormal rCBF compared to an age-matched control population of healthy volunteers (using the Wilcoxon 2-sample test with Bonferroni's correction). The average number of abnormal regions of interest was 4.7. The percentage of patients with abnormal SPECT-CBF or the total number of abnormal regions of interest (ROIs) per patient showed no correlation to duration of epilepsy or seizure load (number of seizures per year x epilepsy duration) or seizure type. Neither were the rCBF changes prognostic for the outcome as measured by the Engel score. In 20 patients ictal SPECT of rCBF was additionally performed. In 2 cases it added further information to the patient evaluation.

Utility of interictal SPECT of rCBF for focal diagnosis of the epileptogenic zone(s)

With Single Photon Emission Computed Tomography (SPECT) of regional cerebral bloodflow (rCBF) ictally and interictally, regional changes of rCBF can be detected in many cases with medically intractable complex partial seizures. Interictal SPECT shows abnormal rCBF in the epileptogenic temporal lobe in 40% to 85% of the patients. A critical survey of the methodological problems considering isotopes, scanners, data analysis and patient population is presented here as well as a few semi-quantitative studies including our own. It is concluded, that SPECT of rCBF is a useful, non-invasive method of localizing the epileptogenic zone in patients with severe partial focal epilepsy. Ictal SPECT of rCBF has a higher predictive value and is more sensitive than interictal studies for localization of the seizure focus. Interictal SPECT using a high-resolution system obtains an almost as high frequency of localization of the focus. With low resolution scanners, a minor frequency is observed. Both interictal and ictal SPECT recordings should be obtained for localization of the epileptogenic focus in presurgical cases as interictal hypoperfusion and ictal hyperperfusion demonstrated in the same focal area are highly characteristic of a seizure focus.

[Preoperative EEG in medically intractable epilepsy]

The aim of the preoperative neurophysiological investigations is to identify the primary epileptogenic focus and its relation to functional cortical areas. The investigations include interictal and ictal extracranial (scalp) electroencephalography (EEG) and invasive methods (depth, subdural, foramen ovale electrodes and peroperative electrocorticography). If an epileptic focus is located in the anterior part of the temporal lobe by the use of scalp EEG, this is normally regarded as sufficient for an anterior lobectomy. However, because of poor spatial resolution by scalp EEG, it is difficult to separate mesial from lateral foci, identify the exact extent of posterior temporal or extra-temporal foci, identify the primary focus in patients with bilateral abnormalities and identify cases with minor scalp EEG-changes. As invasive EEG shows higher spatial resolution and gives an opportunity to evaluate functional areas, invasive EEG has significant advantages in these patients. Use of invasive EEG bears a slightly increased risk and discomfort to the patient, but is necessary in the presurgical evaluation of some patients suffering from medically intractable epilepsy.

Brain extraction and distribution of 99mTc-bicisate in humans and in rats

Blood-brain barrier (BBB) passage of the flow tracer ethylenediylbis-L-cystein diethylester (bicisate, ECD) was measured repeatedly in five patients by means of the intravenous (i.v.) double-indicator technique using 24Na+ as an intravascular cotracer. After i.v. injection, the arterial concentration curve of 99mTc-bicisate was delayed and dispersed compared with that of the intravascular cotracer, presumably due to lung retention of the flow tracer. The corrected cerebral venous output curves were fitted using a three-compartment model with four parameters. At resting cerebral blood flow (CBF) values, the unidirectional brain extraction was 0.57 +/- 0.05, the permeability-surface area product for passage from blood to brain (PS1) was 0.48 +/- 0.07 ml/g/min, and the distribution volume for bicisate was 0.74 +/- 0.20 (mean +/- SD). In a single patient, BBB transport after i.v. injection of bicisate was compared with that of a similar flow tracer, d,l-hexamethylpropyleneamine oxime (HM-PAO), and similar values were found for the two tracers. In 19 rats, the brain extraction of bicisate was measured by means of the intracarotid double-indicator technique. The brain extraction was measured at resting, decreased, and increased CBF values. Low CBF values were obtained by hyperventilation and high values by hypercapnia. The degree of backflux of tracer from brain to blood was evaluated by means of the three-compartment model and was found to be negligible in these experiments. The brain extraction was 0.70 +/- 0.1 and PS1 was 0.94 +/- 0.27 ml/g/min. During hypercapnia, CBF increased from 0.77 to 1.09 ml/g/min, leading to a significant decrease in brain extraction, from 0.70 to 0.56.(ABSTRACT TRUNCATED AT 250 WORDS)

99mTc-bicisate (neurolite) SPECT brain imaging and cognitive impairment in dementia of the Alzheimer type: a blinded read of image sets from a multicenter SPECT trial

A blinded read of images obtained with 99mTc-bicisate and single photon emission computed tomography (SPECT) was conducted to determine if a relationship exists between the severity of abnormalities on SPECT brain images and the severity of cognitive impairment in patients with dementia of the Alzheimer type (DAT) and to examine the interreader agreement for visual reading of images in a multicenter SPECT study. Images for a total of 86 subjects were available for the blinded read. The images for 28 subjects were rated as noninterpretable due to technical inadequacies. Images for 58 subjects (45 DAT patients and 13 normal volunteers) from 10 SPECT centers were selected for further analyses. The severity of abnormality was rated as mild, moderate, or severe by three readers. In DAT patients, a significant negative correlation (p < 0.05) of Mini-Mental State Examination (MMSE) score with global severity of abnormality was noted for two of the three readers. A significant correlation (p < 0.05) between MMSE score and severity of abnormality was observed for all three readers for the posterior temporoparietal region. The blinded readers rated a median of 92.3% of normal volunteers' images as normal and a median of 82.2% of DAT patients' images as abnormal. For the regional severity of abnormality, the median percentage interrater agreement across all regions ranged from 95 to 100% in normal volunteers and from 81 to 98% in DAT patients. These results suggest that SPECT brain imaging with 99mTc-bicisate provides functional information about the severity of cognitive impairment in DAT patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Retention of 99mTc-bicisate in the human brain after intracarotid injection

99mTc-bicisate (ECD) was injected as a bolus into the internal carotid artery, and cerebral uptake and retention were recorded with fast-rotating single photon emission computed tomography (SPECT) equipment in four patients suffering from temporal lobe epilepsy. Quantitative regional cerebral blood flow (rCBF) was measured tomographically with the 133Xe inhalation technique. We applied a three-compartment kinetic model and algorithms modified from a previous analysis of 99mTc d,l-hexamethylpropyleneamine oxide (HM-PAO) kinetics. The bicisate brain uptake and retention curve was very similar to that of HM-PAO, and it can be described by a triexponential function including an initial steep component representing the vascular transmitted spike, a second less steep component representing back-diffusion from brain tissue to blood, and a third, very slow component, representing the very slow loss due to incomplete retention of the deesterified hydrophilic metabolites. Computerized curve-fitting on data from three patients gave average kinetic values for the first-passage (unilateral) extraction of E = 0.60 (range, 0.59-0.61); the overall retained fraction of the tracer supplied was R = 0.44 (0.43-0.45), and the conversion/clearance ratio was alpha = k3/k2 = 2.59 (2.38-2.77). This alpha is higher than that for HM-PAO, and therefore bicisate uptake as a function of blood flow is more linear than in HM-PAO. Less correction for backdiffusion is therefore needed. From 1 to 24 h there was an average loss of hydrophilic tracer of 3.5%/h, but the late distribution images were essentially unchanged over time, pointing to practically the same rate of loss in all regions.

High resolution SPECT with [99mTc]-d,l-HMPAO in normal pressure hydrocephalus before and after shunt operation

Cranial CT and high resolution measurements of regional cerebral blood flow (rCBF) with brain dedicated single photon emission computer tomography (SPECT) and [99mTc]-d,l-hexamethylpropyleneamine oxime ([99mTc]-d,l-HMPAO) were performed before and after shunt operation in 14 consecutive patients with dementia and normal pressure hydrocephalus (NPH). When compared with a control group of 14 age matched healthy volunteers, the group of NPH patients was characterised by an enlarged subcortical low-flow region, significantly reduced rCBF and enhanced side-to-side asymmetry of rCBF in the central white matter, and enhanced side-to-side asymmetry in the inferior and mid-temporal cortex. Global CBF was normal. Shunt operation reduced the mean area of the ventricles on CT and of the subcortical low-flow region on SPECT. Global CBF was unchanged. All 14 patients had an abnormal pre-shunt rCBF pattern with enlargement of the subcortical low flow region, focal cortical blood flow deficits, or both. Shunt operation improved the clinical status in 11 patients, and the area of the subcortical low flow region correctly classified 3/3 unimproved and 10/11 improved patients. Shunt operation normalised or reduced the area of the subcortical low flow region in nine of 10 patients. It is concluded that SPECT with [99mTc]-d,l-HMPAO is a useful supplement in the diagnosis of NPH versus normal ageing, and that SPECT may help to identify patients not likely to benefit clinically from surgery.

Regional cerebral blood-flow measured by HMPAO and SPECT in a 5-year-old boy with Landau-Kleffner syndrome

We present a 5-year-old boy with Landau-Kleffner syndrome, whose clinical manifestations were very similar to cases previously reported in the literature. CT and MRI scan failed to document any morphological abnormalities of his brain. However, high resolution rCBF imaging by HMPAO and SPECT demonstrated relatively low-flow areas in the left middle frontal gyrus and the right mesiotemporal/hippocampal region corresponding to the localization of EEG changes.

Ischaemia-induced (symptomatic) migraine attacks may be more frequent than migraine-induced ischaemic insults

Fifteen consecutive patients with a diagnostic problem of ischaemia-induced migraine with aura (symptomatic migraine) or migraine-associated ischaemia (migrainous infarction) were studied in order to elucidate the mechanisms. Three had a 1 month flurry of daily attacks of migraine auras with or without headache. A severe internal carotid stenosis/occlusion and reduced regional cerebral blood flow (rCBF) was demonstrated. Borderline ischaemia may thus prime the brain for developing migrainous aura with or without migraine (symptomatic migraine). Four patients had a combination of permanent deficits after the very first migraine attack, severe atherosclerosis, risk factors for stroke, high age and no family history of migraine. In these cases the evidence indicates that thromboembolic ischaemia had triggered an attack of migraine with aura (likely symptomatic migraine). Three young females presented long-lasting typical and severe idiopathic migraine with aura. Attack-associated rCBF reduction was likely to have caused permanent, mild, visual or somatosensory deficits (migrainous infarction). In five patients the relationship between migraine and stroke remained unresolved. It seems that ischaemia-induced migraine attacks may be more frequent than migraine-induced ischaemic insults. Therefore, migraine is not as strong a risk factor for stroke as indicated by the mere coincidence of the two disorders.

Reduced regional cerebral blood flow in Huntington's disease studied by SPECT

Regional cerebral blood flow (rCBF) was studied in 18 patients with Huntington's disease (HD) and 19 age- and sex-matched controls with high resolution single photon emission computerised tomography (SPECT), using Tc-99m-HMPAO. Significant reductions in tracer uptake were found in the caudate and lentiform nuclei (20 and 8%) and in the cerebral cortex, especially in the frontal and parietal areas (11-13%). No significant reductions were found in the thalamus, mesial temporal cortex, and occipital cortex. Fourteen patients had neuropsychological testing. Relationship between rCBF and cognitive function was tested by regression analysis. A linear relationship was found between test scores of Wisconsin Card Sorting Test, Picture Arrangement Test and blood flow in the caudate nucleus. Other tests of cognitive function (Block Design Test, Face and Word Recognition Test, Street Fragmented Pictures Test, and Similarities Test) correlated better with flow in the cortical regions believed to be involved in solving those particular tests. These findings indicate, that blood flow is reduced in both cortical and subcortical structures in symptomatic HD, and that both reductions in cortical and subcortical blood flow may be related to cognitive function in HD.

[Psychosocial consequences and surgical treatment of epilepsy. A review]

Epilepsy is one the commonest neurological diseases. In 25% of the cases, particularly in patients with temporal foci, the seizures prove to be resistant to medicinal treatment. Several investigations have stressed that these patients have pronounced psychosocial problems which may be more important to the patient than the actual seizures. Taking into consideration the WHO definition of health as complete physical, mental and social well-being, patients with epilepsy have problems in all of these dimensions. The major problems are social isolation and employment. Surgical treatment of epilepsy has a pronounced effect on the seizures in 90% of the operations in the best series but it is still uncertain whether reduction in the number of seizures also implies better quality of life. The present data suggest improvement in the psychosocial conditions of the patients who functioned best preoperatively and who became seizure-free after operation. The importance of further longitudinal studies emphasizing the psychosocial aspects is stressed.

[3-year experiences with surgical treatment of epilepsy at the Hvidovre hospital]

The results of a retrospective survey of 48 patients submitted to neurosurgery for medically intractable epilepsy are presented. Twenty-eight patients were treated with selective amygdalohippocampectomy, one with temporal lobe resection, 12 with anterior callosotomy and seven with a total callosotomy. Of the amygdalohippocampectomized patients and the one with temporal lobe resection (n = 29), 52% were seizure free, 17% experienced rare seizures, 7% had a worthwhile improvement while 24% observed no worthwhile improvement (follow-up time 6 to 36 months). Of the callosotomized patients, 11% were free from generalized seizures, 69% had a significant seizure reduction and 18% experienced no worthwhile improvement. The observed neurological complications were: one patient had hemianopia, one had superior quadrant anopia, four developed unilateral anosmia and one complete anosmia. The callosotomized patients, with two exceptions, were all mentally and physically handicapped. In the callosotomy group, two patients died, one from a intracerebral hematoma three months after the operation and another patient seven months postoperatively from unknown causes.

[Surgical treatment of epilepsy resistant to drug therapy. A review]

The prevalence of epilepsy is 7-9 cases per 1,000 population, corresponding to 440,000 individuals in Denmark. Approximately 1/4 of these individuals have seizures refractory to anticonvulsant medications and most of them have an epileptic focus in the temporal lobe. Epilepsy refractory to anticonvulsant medication is an incapacitating disease with high costs for the person and the society. The main problems are polypharmacy with side effects, suspicion of neurodegenerative consequences and a higher mortality. The modern era of epilepsy surgery began more than 100 years ago and since then, the developments in neurophysiology and neuroimaging have made it possible to demonstrate the epileptic focus with relatively high precision. As a consequence of this, the volume of the resected tissue has diminished and the operative complications become less frequent. The somatic and neuropsychological effects of a cortical resection are discrete and compensated by a general improvement in performance. Surgical treatment of epilepsy should no longer be considered as a last resort, but as a realistic treatment in cases of medication failure.

99mTc-d,l-HMPAO and SPECT of the brain in normal aging

Single photon emission computed tomography (SPECT) with 99mTc-d,l-hexamethylpropyleneamine oxime (99mTc-d,l-HMPAO) was used to determine global and regional CBF in 53 healthy subjects aged 21-83 years. For the whole group, global CBF normalized to the cerebellum was 86.4% +/- 8.4 (SD). The contribution of age, sex, and atrophy to variations in global CBF was studied using stepwise multiple regression analysis. There was a significant negative correlation of global CBF with subjective ratings of cortical atrophy, but not with ratings of ventricular size, Evans ratio, sex, or age. In a subgroup of 33 subjects, in whom volumetric measurements of atrophy were performed, cortical atrophy was the only significant determinant for global CBF, accounting for 27% of its variance. Mean global CBF as measured with the 133Xe inhalation technique and SPECT was 54 +/- 9 ml/100 g/min and did not correlate significantly with age. There was a preferential decline of CBF in the frontal cortex with advancing age. The side-to-side asymmetry of several regions of interest increased with age. A method was described for estimation of subcortical CBF, which decreased with advancing cortical atrophy. The relative area of the subcortical low-flow region increased with age. These results are useful in distinguishing the effects of age and simple atrophy from disease effects, when the 99mTc-d,l-HMPAO method is used.

Adolescent addiction. Assessment and identification

Adolescents who are addicted to drugs present unique assessment and diagnostic problems. The primary drugs used by adolescents are alcohol, marijuana, and cocaine, respectively. The adolescent who uses drugs in a regular and frequent manner is affected more rapidly than is the adult who uses in the same way and for the same length of time. The social and emotional skills usually acquired during this period of rapid growth often are not learned when the adolescent is abusing drugs, and this results in psychosocial stunting of development. Drugs and alcohol have been implicated in teenage traffic accidents, school drop out rates, promiscuity, crime, and suicide. Assessing adolescent drug use and potential addiction is not difficult once good history and examination techniques are acquired. This article presents techniques for assessing and identifying addicted adolescents.

Timing and topography of cerebral blood flow, aura, and headache during migraine attacks

Ten years of study has resulted in considerable but fragmented knowledge about regional cerebral blood flow in migraine with aura (classic migraine). In the present study, the number of repeatedly studied patients (n = 63) was large enough to determine statistically significant sequences of events and statistically significant spatial relations. The first observable event was a decrease of regional cerebral blood flow posteriorly in one cerebral hemisphere. Further development of this pathological process was accompanied by the aura symptoms. Thereafter headache occurred while regional cerebral blood flow remained decreased. During the headache phase, regional cerebral blood flow gradually changed from abnormally low to abnormally high without apparent change in headache. In some patients headache disappeared while regional cerebral blood flow remained increased. Although regional cerebral blood flow reduction and aura symptoms in the great majority of patients were unilateral, one-third had bilateral headache. Unilateral headache usually localized to the side on which regional cerebral blood flow was reduced and from which the aura symptoms originated (i.e., aura symptoms were perceived to occur contralaterally but presumably originated in the hypoperfused hemisphere). Our results suggest a simple model for migraine attacks: A pathological disturbance in one cerebral hemisphere causes the aura symptoms and after a time delay, it also causes the headache by stimulating local vascular nociceptors. Bilateral headache caused by a unilateral cerebral disturbance may be explained by recent neuroanatomical and neurophysiological findings.

The effect of the benzodiazepine antagonist flumazenil on regional cerebral blood flow in human volunteers

The influence of the benzodiazepine antagonist flumazenil on regional cerebral blood flow (rCBF) was investigated in ten healthy, alert volunteers. The design was a randomized, placebo-controlled, double-blind, cross-over study. rCBF was measured by 133-Xe inhalation and single photon emission computerized tomography, SPECT, immediately before, and 5 and 35 min after intravenous injection of flumazenil 1.0 mg or placebo. In addition, mean arterial blood pressures or PaCO2, rCBF were analysed for changes in various regions of interest (RoI). No alterations were found either in the global CBF or in rCBF in RoI after flumazenil injection. The results showed that a clinically active dose of flumazenil did not directly affect the cerebral circulation in the normal brain and indicated absence of significant intrinsic activity of the drug.

Cerebral blood flow in progressive aphasia without dementia. Case report, using 133xenon inhalation, technetium 99m hexamethylpropyleneamine oxime and single photon emission computerized tomography

We report a case of progressive aphasia without clinical signs of intellectual or behavioral impairment, satisfying Mesulam's clinical criteria of primary progressive aphasia, as 4 yrs of extensive psychometric testing and radiological imaging, comprising CT and MRI, failed to detect evidence of relevant involvement outside the left perisylvian regions. Cranial CT was normal but MRI showed multiple bilateral lesions in the deep white matter. Cerebral blood flow (CBF) studies by single photon emission computerized tomography, however, showed an initial frontotemporal focus of hypoperfusion that progressively extended to include most of the ipsilateral hemisphere and the contralateral frontal lobe. This suggests that CBF imaging may yet be the most sensitive technique in revealing subclinical injury in the degenerative brain diseases of focal onset.

Computerized analysis of cerebral blood flow autoregulation in humans: validation of a method for pharmacologic studies

Cerebral blood flow (CBF) autoregulation in the supine position without tilting using systemic ganglion-blockade (trimetaphane camphosulfonas) combined with lower body vacuum is evaluated. Automatic computerized curve-fitting analysis for assessment of the lower limit (LL) of autoregulation is introduced. Global CBF was evaluated using the arteriovenous-O2-difference method in 12 volunteers and in seven patients with chronic arterial hypertension. Classic autoregulatory curves were found in all cases. The LL of CBF autoregulation was 85 +/- 5 mm Hg in the volunteers and 113 +/- 7 mm Hg in the hypertensive patients. In seven of the volunteers, the autoregulatory study was performed twice in 1 day; a small but significant shift of LL toward higher blood pressure (BP) values was observed in the second test (3 mm Hg). In five of the hypertensive patients, regional CBF (rCBF) was measured by single-photon emission computed tomography (SPECT) of inhaled xenon-133. The median global CBF decreased from 62 to 45 ml/100 g/min during the mean arterial BP (MABP) decrease from 110 to 68 mm Hg. The regional distribution of CBF was normal at baseline as well as during hypotension. The method is suitable for pharmacologic studies of cerebral autoregulation.

The effect of fosinopril sodium on cerebral blood flow in moderate essential hypertension

The effect of the angiotensin converting enzyme (ACE) inhibitor fosinopril sodium on regional cerebral blood flow (rCBF) was investigated in 8 patients with moderate essential hypertension. A constant dose of chlorthalidone (25 mg/day) was given to stimulate the renin angiotensin system, and fosinopril sodium was given in incremental doses (10 to 40 mg/day) with the aim of obtaining a diastolic blood pressure at or below 90 mm Hg. Regional CBF was measured with xenon-133 inhalation tomography. Repetitive measurements were made at the start of treatment and again after 4 to 12 weeks treatment in the resting supine position, and during lower body negative pressure (LBNP) as a substitute for the upright position. Four hours after the first 10 mg dose of fosinopril the mean arterial pressure (MAP) had been reduced from 127 +/- 13 mm Hg to 105 +/- 9 mm Hg (P less than .01) without any significant change in mean CBF (55 +/- 9 mL/(100 g X min) at baseline versus 52 +/- 9 mL/(100 g X min) after fosinopril). After prolonged treatment with chlorthalidone and fosinopril, mean CBF was still unchanged from baseline levels, when measured 4 and 24 h after a single dose of fosinopril, despite a 10% reduction in MAP (P less than .01). LBNP did not lead to any significant change in rCBF. The regional distribution of CBF was normal in all patients throughout the study. We conclude that treatment with fosinopril sodium causes a moderate fall in blood pressure without any adverse effects on rCBF.

Angiotensin converting enzyme inhibition, CBF autoregulation, and ICP in patients with normal-pressure hydrocephalus

Fourteen patients with normal pressure hydrocephalus had the autoregulation of cerebral blood flow (CBF) and intracranial pressure (ICP) investigated. In 8 of the patients the effect of Captopril on ICP and CBF was also investigated. The mean arterial blood pressure (MABP) was 109 mmHg (intra-arterially), and ICP was 11 mmHg (intraventricularly). Changes in global CBF were estimated by the arterio-venous oxygen difference method. The autoregulation of CBF was present in 13 of the patients (p less than 0.01). The lower limit of CBF autoregulation was 86% of the baseline perfusion pressure. One hour after 50 mg of captopril perorally, MABP was reduced 16 mmHg, and ICP and CBF were unchanged. The autoregulation was maintained and the lower limit was decreased 19 mmHg. Thus patients would be expected to benefit from captopril treatment in hypotensive anaesthesia.

SPECT in the presurgical evaluation of patients with temporal lobe epilepsy--a preliminary report

Twenty-eight patients with drug resistant temporal lobe epilepsy (DRTLE) were studied using single photon emission computed tomography (SPECT) using xenon-133 inhalation and Tc99m-d, 1-HMPAO with TOMOMATIC 64 as part of a presurgical evaluation programme. The visually evaluated flow-images were studied after blinding and the results subsequently compared to the EEG, MRI and CT scanning studies. In 24 patients a significant low flow region was seen in one temporal lobe. The SPECT result corresponded to the EEG findings in all but 6 patients. In 2 of these patients no side localization was indicated by EEG, while in four patients the EEG suggested that the opposite side was epileptogenic. Ictal SPECT and MRI/CT agreed with the resting SPECT study in three patients, while one patient has remained undiagnosed with respect to side-localization. In 14 patients discordance between SPECT and the CT scan was observed, but in 11 of these patients the SPECT study correlated with the other focal diagnostic tools. In 11 of the 21 patients studied by MRI, the results corresponded to SPECT; in 7 of the 10 which did not correspond, ictal studies of EEG and SPECT defined the side, in four of these 7 patients. Using the neuroimaging tools in concert 16 patients have been selected for surgery. All patients have benefited from surgery. These preliminary results correspond favourably with earlier studies comparing SPECT and PET with CT, MR and EEG.

Angiotensin-converting enzyme inhibition and regional cerebral blood flow in acute stroke

The effect of the angiotensin-converting enzyme (ACE) inhibitor captopril on regional cerebral blood flow (rCBF) was studied in 12 patients within 5 days after their first acute stroke. rCBF was studied by xenon-133 inhalation and single-photon emission computed tomography (SPECT) scan before and 1 h after oral administration of 25 mg captopril. No increase in rCBF was observed in any of the 12 patients included in the study. In only one patient was there a slight redistribution of blood flow in favor of the low-flow area, but the absolute flow value did not increase. Captopril did not cause any significant change in mean hemispheric blood flow, mean arterial blood pressure (MAP), or end-expiratory CO2 fraction (FECO2). The assumption that ACE inhibition might increase cerebral blood flow in the periinfarct zone and preserve some still viable brain tissue could not be verified in the present study.

Angiotensin converting enzyme inhibition and cerebral blood flow autoregulation in normotensive and hypertensive man

The acute effect on the lower limit of cerebral blood flow (CBF) autoregulation of an angiotensin converting enzyme (ACE) inhibitor, captopril, was studied in normotensive volunteers and in hypertensive patients. Baseline CBF was measured using xenon-133 inhalation tomography, and changes in CBF were measured using the arterio-venous oxygen difference method. Cerebral blood flow autoregulation was studied in two separate normotensive groups, one group of 12 volunteers serving as a control, and one group of 12 volunteers studied after the administration of captopril 50 mg. In a group of seven hypertensive patients CBF autoregulation was studied before and 1 h after the administration of captopril 25 mg. In the normotensive volunteers the median lower limit of CBF autoregulation was 83 and 74 mmHg in the untreated and the captopril-treated group, respectively, with no significant difference between the two groups. In five of the hypertensive patients the lower limit of CBF autoregulation was lowered by captopril, in median by 22 mmHg. However, in two patients it was increased, by 3 and 13 mmHg, respectively. It is proposed that the shift in the lower limit of CBF autoregulation seen in some of our cases, and which has previously been documented in experimental studies, may be dependent on the activity of the sympathetic nervous system.

Assessment of the arterial input curve for [99mTc]-d,l-HM-PAO by rapid octanol extraction

The in vitro conversion of the lipophilic molecule [99mTc]-d,l-hexamethylpropyleneamine oxime [( 99mTc]-d,l-HM-PAO) to a hydrophilic form was studied in saline, plasma, and blood at 37 degrees C by paper chromatography and by octanol extraction. The octanol:saline ratio was 79.9. From this value and the corresponding octanol: plasma and octanol:blood partitioning values, an estimate of the transport of the lipophilic compound by various components of blood was made: 20% is carried in hemoglobin, 53% by the plasma proteins and 27% by the water phases of the red blood cell and plasma. Octanol extraction provided a rapid method for measuring the radiochemical purity (RCP) of lipophilic [99mTc]-d,l-HM-PAO. In saline, the RCP declined with a half-life of more than 1 h. In human plasma and whole blood, the conversion of [99mTc]-d,l-HM-PAO was biexponential due to the differences in the conversion rates of the d and l isomeric forms. The initial half-life representing the conversion rate of the l form was 1.7 min in blood and 1.4 min in plasma, while the conversion half-life of the d form was 7.4 and 24.4 min, respectively. In vivo, the RCP of arterial blood sampled after an i.v. bolus injection showed an initial peak value of 75% (68-79%) during the initial, first passage of the bolus. It declined to approximately 35% (29-40%) after 1.5 min and reached very low levels (about 1%) at 6 to 10 min. Quantitative measurements of cerebral blood flow using [99mTc]-d,l-HM-PAO necessitates a rapid method for RCP determination in arterial blood such as the one described here.

SPECT with [99mTc]-d,l-hexamethyl-propylene amine oxime (HM-PAO) compared with regional cerebral blood flow measured by PET: effects of linearization

In order to validate the use of technetium-99m-d,l-hexamethylpropyleneamine oxime (HM-PAO) as a flow tracer, a total of 21 cases were studied with single photon emission computerized tomography (SPECT), and compared to regional cerebral blood flow (rCBF) measured by position emission tomography (PET) using the oxygen-15 CO2 inhalation technique. Although HM-PAO SPECT and rCBF PET images showed a similar distribution pattern the HM-PAO SPECT image showed less contrast between high and low activity flow regions than the rCBF image and a nonlinear relationship between HM-PAO activity and rCBF was shown. Based on the assumption of flow-dependent backdiffusion of HM-PAO from the brain, we applied a "linearization algorithm" to correct the HM-PAO SPECT images. The corrected HM-PAO SPECT images revealed a good linear correlation with rCBF (r = 0.901, p less than 0.001). The results indicated HM-PAO can be used as a flow tracer with SPECT after proper correction.

The retention of [99mTc]-d,l-HM-PAO in the human brain after intracarotid bolus injection: a kinetic analysis

[99mTc]-d,l-HM-PAO (HM-PAO) was injected rapidly into the internal carotid artery and its retention in the brain was recorded by external scintillation cameras in eight human subjects. A model is described based on three compartments: the lipophilic tracer in the blood pool of the brain, the lipophilic tracer inside the brain, and the hydrophilic form retained in the brain. The retention curve initially drops abruptly, corresponding to the nonextracted fraction of the injectate leaving the brain; it then falls exponentially towards the asymptotic level of the fractional steady-state retention R. Cerebral blood flow (F) was measured using the xenon-133 intracarotid injection method. The first-pass extraction E of HM-PAO was calculated from F using an empiric regression equation. The residue curves for the whole brain after intracarotid HM-PAO injection were analyzed to yield a retention fraction (R') and the brain clearance backflux constant of lipophilic HM-PAO (k). From the kinetic model and the measured values of R', k, and F, the following parameter values could be calculated: the average retained fraction of all tracer supplied to the brain, R = 0.38 +/- 0.05 (mean +/- SD), the conversion rate constant (lipophilic to hydrophilic tracer) in the brain k3 = 0.80 +/- 0.12 min-1, the efflux rate constant (brain to blood) k2 = 0.69 +/- 0.11 min-1, the conversion/clearance ratio alpha = k3/k2 = 1.18 +/- 0.25, the influx (blood clearance) constant K1 = 0.45 +/- 0.11 ml/g/min, and the brain/blood partition ratio lambda = K1/k2 = 0.67 +/- 0.23 ml/g. Using the kinetic model and assuming constancy of alpha, an algorithm was developed that corrects for the blood flow dependent backflux of HM-PAO and results in a more linear relation between regional cerebral blood flow (rCBF) and HM-PAO distribution.

Quantitative measurements of cerebral blood flow using SPECT and [99mTc]-d,l-HM-PAO compared to xenon-133

The uptake and retention in a 2 cm thick brain section was recorded serially by SPECT after i.v. injection of [99mTc]-d,l-HM-PAO (HM-PAO). In 16 patients, the fraction of the administered dose retained by the brain was 5.2 +/- 1%, showing a peak after 40-50s, then decreasing by 10% within the first 10 min and then by only 0.4% per hour. The image contrast was measured in each patient as the regional hemispheric asymmetry difference in percent of the highest value of the two regions. It decreased from 31% at 30-40 s to 25% at 10 min. At 24 h, a value of 19% was reached. Using the images obtained at 10 min after injection, a region to region comparison of the original and corrected HM-PAO images to the xenon-133 regional cerebral blood flow (rCBF) images was performed. Forty-four patients with stroke, epilepsy, dementia, basal ganglia disease, and tumors and control subjects were included in this comparison. The algorithm proposed by Lassen et al. was used to correct the original images for back diffusion of tracer (brain to blood); a good correlation very close to the line of identity between the corrected HM-PAO and xenon-133 data was obtained when using a conversion/clearance ratio of 1.5 and when the noninvolved hemisphere was used as a reference region (r = 0.86, p less than 0.0001). Serial arterial and cerebral venous blood sampling was performed over 10 min following i.v. injection of HM-PAO in six patients. An overall brain retention fraction of 0.37 +/- 0.03 (mean +/- SEM) was calculated from the data. An average CBF of 0.62 +/- 0.12 ml/g/min was determined on the basis of the Fick principle; this compared to a value of 0.59 +/- 0.09 ml/g/min (mean +/- SEM) measured by the xenon-133 inhalation method. The two sets of CBF values correlated linearly with a correlation coefficient of 0.97 (p less than 0.01). Inserting the average CBF value for the hemisphere as measured by the Fick principle into the algorithm described by Lassen et al. yields absolute rCBF values (ml/g/min) directly from the corrected HM-PAO images.(ABSTRACT TRUNCATED AT 400 WORDS)

The retention mechanism of technetium-99m-HM-PAO: intracellular reaction with glutathione

Preparations of d,l- and meso-hexamethylpropyleneamine oxime (HM-PAO) labeled with technetium-99m were added to rat brain homogenates diluted with phosphate buffer (1:10). The conversion of d,l-HM-PAO to hydrophilic forms took place with an initial rate constant of 0.12 min-1. Incubation of the brain homogenate with 2% diethyl maleate for 5 h decreased the homogenate's measured glutathione (GSH) concentration from 160 to 16 microM and decreased the conversion rate to 0.012 min-1. Buffered aqueous solutions of glutathione rapidly converted the HM-PAO tracers to hydrophilic forms having the same chromatographic characteristics as found in the brain homogenates. The rate constant for the conversion reaction of d,l-HM-PAO in GSH aqueous solution was 208 and 317 L/mol/min in two different assay systems and for meso-HM-PAO the values were 14.7 and 23.2 L/mol/min, respectively. Rat brain has a GSH concentration of about 2.3 mM and the conversion of the d,l-HM-PAO due to GSH alone should proceed with a rate constant of 0.48 to 0.73 min-1 and be correspondingly 14-fold slower for meso-HM-PAO. In human brain, the in vivo data of Lassen et al. show a conversion rate constant of 0.80 min-1. This correspondence of values supports the notion that GSH may be important for the in vivo conversion of 99mTc-labeled HM-PAO to hydrophilic forms and may be the mechanism of trapping in brain and other cells. A kinetic model for the trapping of d,l- and meso-HM-PAO in tissue is developed that is based on data of GSH concentration in various organs.(ABSTRACT TRUNCATED AT 250 WORDS)

Extraction of [99mTc]-d,l-HM-PAO across the blood-brain barrier

The initial extraction (E) across the blood-brain barrier (BBB) of [99mTc]-d,l-HM-PAO after intracarotid injection was measured in 14 Wistar rats and 6 patients using the double indicator, single injection method with Na-24 as the cotracer. In both series, cerebral blood flow (CBF) was measured using the initial slope of the xenon-133 washout curve after intracarotid bolus injection. In rats, bolus size (20 or 120 microliters), bolus type (saline or 10% albumin), or CBF were changed. First-pass extraction was dependent on CBF (p less than 0.001): With a small bolus of saline and at resting CBF (0.75 ml/g/min), E was 0.81, decreasing to 0.56 at a high CBF (1.5 ml/g/min). The calculated permeability surface area product (PS) increased linearly from 1.2 to 1.5 ml/g/min when CBF increased from 0.8 to 1.5 ml/g/min (p less than 0.01). E was found to increase when the bolus volume of saline was increased from 20 to 120 microliters, while using a 120 microliters bolus containing 10% albumin resulted in a decrease in E. This suggests that HM-PAO binding to albumin is not totally and rapidly reversible during a single passage through brain capillaries and that binding to blood elements may reduce the apparent extraction across brain capillaries. In patients using a bolus of 1 ml saline, E decreased linearly with increasing CBF (r = -0.81, p less than 0.001). For a CBF of 0.59 ml/g/min and an average apparent E of 0.72, an apparent PS product of 0.76 ml/g/min was calculated.(ABSTRACT TRUNCATED AT 250 WORDS)

Symptoms of classic migraine attacks: modifications brought about by metoprolol

There is little information available concerning whether, and to what extent, migraine-prophylactic agents interfere with the symptoms of migraine attacks. The present study is a placebo-controlled, double-blind study concerning metoprolol in classic migraine. The data refer to the symptoms of single migraine attacks. During metoprolol treatment more attacks were characterized as mild (p = 0.002), and mean global rating (an integrated estimate of headache intensity and of other discomfort) was lower (4.2 versus 5.2, p = 0.003). The mean headache intensity per attack (1.97 versus 2.15) and the mean duration (5.5 versus 6.8 h) were not significantly different. Consumption of analgesics per attack was lower during metoprolol treatment (0.6 versus 1.1; p = 0.02). Attacks with associated symptoms accompanying the headache were fewer during metoprolol treatment (p = 0.014). Total visual and non-visual aura symptoms occurred with similar frequency, but scintillations and paraesthesia were more frequent during metoprolol treatment, whereas speech disturbances were less frequent. In spite of lower consumption of analgesics, the symptoms appeared milder during metoprolol than during placebo. The pattern of changes indicates that metoprolol exerts its action via the sympathetic nervous system; peripheral vasoconstriction is hardly the underlying mechanism of action.

Danish very-low-dose aspirin after carotid endarterectomy trial

The effect of very-low-dose aspirin as an antithrombotic agent was evaluated blindly in 301 patients who had recently undergone carotid endarterectomy. After randomization, 150 patients received aspirin and 151 received placebo. The two groups were comparable with regard to age, sex, blood pressure, previous cerebrovascular events, and smoking habits. The effect of the study medication on platelet aggregation was measured twice in each patient during the first 2 months and at each follow-up visit; the dose was individually adjusted. In 76% of the patients receiving aspirin, 50 mg/day gave satisfactory platelet inhibition, 13% needed 60 mg/day, 8% needed 70 mg/day, and 3% needed 100 mg/day. Platelet aggregation was found to be inhibited in only 1.2% of the measurements in the patients receiving placebo. Observation during treatment averaged 21 months; total intention-to-treat follow-up averaged 25 months. For the combined outcome events of transient ischemic attack, stroke, acute myocardial infarction, and vascular death, aspirin reduced risk by 11% (95% confidence limits: -38% to 48%, p greater than 0.1). Thus, there was no significant effect of very-low-dose aspirin in our trial.

Role of angiotensin in autoregulation of cerebral blood flow

The presence of the renin-angiotensin system (RAS) in extrarenal tissues, namely the vascular wall and brain tissue, is well established. The availability of effective blocking agents, converting-enzyme inhibitors, has made it possible to further elucidate important functions of the extrarenal RAS. We have found that the angiotensin converting-enzyme inhibitor captopril shifts the limits of cerebral blood flow autoregulation to lower blood pressure levels in normotensive and in spontaneously hypertensive rats. This effect may explain our finding of a remarkable preservation of cerebral blood flow, despite significant blood pressure reduction, in patients with chronic heart failure. We suggest that the effect of angiotensin converting-enzyme inhibition on autoregulation of cerebral blood flow is mediated by a dilatation of larger cerebral arteries, which results from inhibition of the vascular tone normally maintained by locally produced angiotensin II.

Delayed hyperemia following hypoperfusion in classic migraine. Single photon emission computed tomographic demonstration

Regional cerebral blood flow (rCBF) was measured in seven patients during classic migraine attacks. Single photon emission computed tomography was performed soon after hospital admission, and three to eight hours, 20 to 24 hours, and one week later after the onset of symptoms. Initially reduced rCBF persisting up to three hours was observed in the hemisphere appropriate to the focal neurologic deficit; hyperperfusion was noted later in the same region in these patients. At 24 hours rCBF was normal in four patients, hyperemia persisted in two patients, and one patient was not restudied. The area of interest demonstrated a mean decrease of 19% +/- 7% in side-to-side asymmetry when compared with the contralateral region. In three to eight hours this reversed to a mean increase of 19% +/- 4% (delayed hyperemia). No asymmetries were observed after one week. The late hyperemic asymmetry often persisted beyond the duration of the clinical headache. It is postulated that this tardive regional hyperperfusion is a consequence of previous focal arteriolar vasoconstriction. This vascular sequence of events further delineates the diagnostic merit of studying rCBF by noninvasive single photon emission computed tomography in migraine.

Classic migraine: effective prophylaxis with metoprolol

Metoprolol slow-release tablets (Durules), 200 mg, given once daily in the morning were compared with placebo in the prophylaxis of classic migraine. The trial comprised eight Scandinavian neurologic centres and was designed as a double-blind cross-over study with 4 weeks' run-in, four weeks washout, and 8 weeks of either treatment. Seventy-seven patients with two to eight migraine attacks per month were entered in the trial, and 73 completed it. A total of 1119 attacks with aura symptoms and 374 without were recorded. Metoprolol was significantly better than placebo with regard to the total frequency of attacks (1.8 versus 2.5 attacks/4 weeks), mean duration of attacks (6.0 versus 8.0 h/attack), mean global rating, and consumption of analgesics per attack. Similar differences could be shown for attacks with aura symptoms alone, except for the duration of attacks. Metoprolol is the first drug for which a prophylactic effect in classic migraine has been convincingly demonstrated.