Executive function and sleep problems in childhood epilepsy.

Pediatric epilepsy has been reported to be associated with both sleep problems and cognitive deficits. In turn, in healthy children, poorer sleep has been associated with deficits in cognitive functioning. We hypothesized that poor sleep in childhood epilepsy may contribute to cognitive deficits. Using actigraphy, we objectively measured the sleep of children with epilepsy alongside that of healthy controls. In contrast to previous reports, we did not find any differences in objectively measured sleep between children with epilepsy and healthy controls. However, significant deficits in cognitive functioning were demonstrated that were not explained by differences in sleep.

Nocturnal haemoglobin oxygen saturation variability is associated with vitamin C deficiency in Tanzanian children with sickle cell anaemia.

AIM: To compare pulse oximetry in children with sickle cell anaemia (SCA) and controls and test the hypothesis that vitamin C deficiency (VCD; <11.4 µmol/L) is associated with nocturnal haemoglobin oxygen desaturation in SCA. METHODS: We undertook nocturnal and daytime pulse oximetry in 23 children with SCA (median age 8 years) with known steady-state plasma vitamin C concentrations and 18 siblings (median 7 years). RESULTS: Median nocturnal delta 12 s index (delta12 s), a measure of haemoglobin oxygen saturation (SpO(2)) variability, was 0.38 (interquartile range 0.28-0.51) in SCA and 0.35 (0.23-0.48) in controls, with 9/23 and 6/18, respectively, having a delta12 s >0.4, compatible with obstructive sleep apnoea (OSA). Eleven of twenty-three with SCA had VCD; logged vitamin C concentrations showed a 66% decrease per 0.1 unit increase in delta12 s ([95% CI -86%, -15%]; p=0.023) and delta12 s >0.4 was associated with VCD (odds ratio 8.75 [1.24-61.7], p=0.029). Daytime and mean nocturnal SpO(2) were lower in SCA but there was no association with vitamin C. CONCLUSION: Obstructive sleep apnoea (OSA), detected from nocturnal haemoglobin oxygen saturation variability, is common in Tanzanian children and associated with vitamin C Deficiency in SCA. The direction of causality could be determined by comparing OSA treatment with vitamin C supplementation.

The course and outcome of unilateral intracranial arteriopathy in 79 children with ischaemic stroke.

Arteriopathies are the commonest cause of arterial ischaemic stroke (AIS) in children. Repeated vascular imaging in children with AIS demonstrated the existence of a 'transient cerebral arteriopathy' (TCA), characterized by lenticulostriate infarction due to non-progressive unilateral arterial disease affecting the supraclinoid internal carotid artery and its proximal branches. To further characterize the course of childhood arteriopathies, and to differentiate TCA from progressive arterial disease, we studied the long-term evolution of unilateral anterior circulation arteriopathy, and explored predictors of stroke outcome and recurrence. From three consecutive cohorts in London, Paris and Utrecht, we reviewed radiological studies and clinical charts of 79 previously healthy children with anterior circulation AIS and unilateral intracranial arteriopathy of the internal carotid bifurcation, who underwent repeated vascular imaging. The long-term evolution of arteriopathy was classified as progressive or TCA. Clinical and imaging characteristics were compared between both groups. Logistic regression modelling was used to determine possible predictors of the course of arteriopathy, functional outcome and recurrence. After a median follow-up of 1.4 years, 5 of 79 children (6%) had progressive arteriopathy, with increasing unilateral disease or bilateral involvement. In the others (94%), the course of arteriopathy was classified as TCA. In 23% of TCA patients, follow-up vascular imaging showed complete normalization, the remaining 77% had residual arterial abnormalities, with improvement in 45% and stabilization in 32%. Stroke was preceded by chickenpox in 44% of TCA patients, and in none of the patients with progressive arteriopathies. Most infarcts were localized in the basal ganglia. In 14 (19%) of TCA patients, transient worsening of the arterial lesion was demonstrated before the arteriopathy stabilized or improved. Thirteen TCA patients (18%) had a recurrent stroke or TIA. Thirty TCA patients (41%) had a good neurological outcome, compared with none of the five patients with progressive arteriopathy. Arterial occlusion, moyamoya vessels and ACA involvement were more frequent in progressive arteriopathies. Cortical infarct localization was significantly associated with poor neurological outcome (OR 6.14, 95% CI 1.29-29.22, P = 0.02), while there was a trend for occlusive arterial disease to predict poor outcome (OR 3.00, 95% CI 0.98-9.23, P = 0.06). Progressive arteriopathy was associated with recurrence (OR 18.77, 95%CI 1.94-181.97, P = 0.01). The majority of childhood unilateral intracranial anterior circulation arteriopathies (94%) have a course that is consistent with TCA, in which transient worsening is common. Although the arterial inflammation probably causing TCA is 'transient', most children are left with permanent arterial abnormalities and residual neurological deficits.

L-Glutamine in sickle cell disease.

L-Glutamine is a conditionally essential amino acid required for synthesis of the pyridines for nucleotides, including nicotinamide adenine dinucleotide (NAD) and glutathione, as well as glutamate, and becomes essential during oxidative stress exposure. The NADH:[NAD⁺ + NADH] (redox) ratio in sickle red blood cells (RBCs) is lower than in normal RBCs, consistent with oxidative stress, therefore glutamine availability is important in sickle cell disease (SCD). RBC glutamine levels vary between SCD studies but the ratio glutamine:glutamate was inversely related to tricuspid regurgitant jet velocity in one. Oral L-glutamine was associated with an increase in NADH and reduction in RBC endothelium adhesion in small studies of SCD patients. In a sickle mouse model, glutamine levels were directly related to cerebral blood flow. Phase II and III randomized, double-blind, controlled trials of L-glutamine 0.6 g/kg/day compared with placebo in children and adults with SCD and = 2 episodes of pain in the previous year provide evidence that L-glutamine is safe and associated with a reduction in painful episodes and in hospitalizations. However, L-glutamine was only tolerated in two-thirds of patients, anemia and hemolysis did not improve and there are few data on mortality and organ complications. Future studies should investigate the effect of other amino acids and total protein intake.

American Society of Hematology 2020 guidelines for sickle cell disease: prevention, diagnosis, and treatment of cerebrovascular disease in children and adults.

BACKGROUND: Central nervous system (CNS) complications are among the most common, devastating sequelae of sickle cell disease (SCD) occurring throughout the lifespan. OBJECTIVE: These evidence-based guidelines of the American Society of Hematology are intended to support the SCD community in decisions about prevention, diagnosis, and treatment of the most common neurological morbidities in SCD. METHODS: The Mayo Evidence-Based Practice Research Program supported the guideline development process, including updating or performing systematic evidence reviews. The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, including GRADE evidence-to-decision frameworks, to assess evidence and make recommendations. RESULTS: The panel placed a higher value on maintaining cognitive function than on being alive with significantly less than baseline cognitive function. The panel developed 19 recommendations with evidence-based strategies to prevent, diagnose, and treat CNS complications of SCD in low-middle- and high-income settings. CONCLUSIONS: Three of 19 recommendations immediately impact clinical care. These recommendations include: use of transcranial Doppler ultrasound screening and hydroxyurea for primary stroke prevention in children with hemoglobin SS (HbSS) and hemoglobin Sß0 (HbSß0) thalassemia living in low-middle-income settings; surveillance for developmental delay, cognitive impairments, and neurodevelopmental disorders in children; and use of magnetic resonance imaging of the brain without sedation to detect silent cerebral infarcts at least once in early-school-age children and once in adults with HbSS or HbSß0 thalassemia. Individuals with SCD, their family members, and clinicians should become aware of and implement these recommendations to reduce the burden of CNS complications in children and adults with SCD.

Cerebral venous sinus thrombosis in children: risk factors, presentation, diagnosis and outcome.

Neuroimaging and management advances require review of indications for excluding cerebral venous sinus (sinovenous) thrombosis (CSVT) in children. Our goals were to examine (i) clinical presentations of CSVT, (ii) prothrombotic risk factors and other predisposing events, (iii) clinical and radiological features of brain lesions in CSVT compared with arterial stroke, and (iv) predictors of outcome. We studied 42 children with CSVT from five European paediatric neurology stroke registries. Patients aged from 3 weeks to 13 (median 5.75) years (27 boys; 64%) presented with lethargy, anorexia, headache, vomiting, seizures, focal signs or coma and with CSVT on neuroimaging. Seventeen had prior chronic conditions; of the 25 previously well patients, 23 had recent infections, eight became dehydrated and six had both. Two children had a history compatible with prior CSVT. Anaemia and/or microcytosis (21 probable iron deficiency, five haemolytic, including two with sickle cell disease and one with beta-thalassaemia) was as common (62%) as prothrombotic disorder (13/21 screened). High factor VIII and homozygosity for the thermolabile methylene tetrahydrofolate reductase polymorphism were the commonest prothrombotic disorders. The superficial venous system was involved in 32 patients, the deep in six, and both in four. Data on the 13 children with bland infarction and the 12 with haemorrhage in the context of CSVT were compared with those from 88 children with ischaemic (AIS) and 24 with haemorrhagic (AHS) arterial stroke. In multiple logistic regression, iron deficiency, parietal infarction and lack of caudate involvement independently predicted CSVT rather than arterial disease. Five patients died, three acutely, one after recurrence and one after 6 months being quadriparetic and blind. Follow-up ranged from 0.5 to 10 (median 1) years. Twenty-six patients (62%) had sequelae: pseudotumour cerebri in 12 and cognitive and/or behavioural disabilities in 14, associated with epilepsy in three, hemiparesis in two and visual problems in two. Eighteen patients, including six with haemorrhage, were anticoagulated. Older age [odds ratio (OR) 1.54, 95% confidence limits (CI) 1.12, 2.13, P = 0.008], lack of parenchymal abnormality (OR 0.17, 95% CI 0.02, 1.56, P = 0.1), anticoagulation (OR 24.2, 95% CI 1.96, 299) and lateral and/or sigmoid sinus involvement (OR 16.2, 95% CI 1.62, 161, P = 0.02) were independent predictors of good cognitive outcome, although the last predicted pseudotumour cerebri. Death was associated with coma at presentation. Of 19 patients with follow-up magnetic resonance (MR) venography, three had persistent occlusion, associated with anaemia and longer prodrome. A low threshold for CT or MR venography in children with acute neurological symptoms is essential. Nutritional deficiencies may be modifiable risk factors. A paediatric anticoagulation trial may be required, after the natural history has been further established from registries of cases with and without treatment.

Nocturnal haemoglobin oxygen desaturation in urban and rural East African paediatric cohorts with and without sickle cell anaemia: a cross-sectional study.

Low haemoglobin oxygen saturation (SpO2) predicts complications in children with sickle cell anaemia (SCA) in the North but there are few data from Africa, where the majority of the patients reside. We measured daytime and overnight SpO2 in children with SCA in routine follow-up clinic, and controls without symptoms of SCA, comparing rural (Kilifi, Kenya) and urban (Dar-es-Salaam, Tanzania) cohorts. Daytime SpO2 was lower in 65 Tanzanian children with SCA (TS; median 97 (IQR 94-100)%); p<0.0001) than in 113 Kenyan children with SCA (KS; 99 (98-100)%) and 20 Tanzanian controls (TC; 100 (98-100)%). Compared with 95 Kenyan children with SCA, in 54 Tanzanian children with SCA and 19 TC who returned for overnight oximetry, mean (KS 99.0 (96.7-99.8)%; TS 97.9 (95.4-99.3)%; TC 98.4 (97.5-99.1)%; p=0.01) and minimum nocturnal SpO2 (92 (86-95)%; 87 (78.5-91)%; 90 (83.5-93)% p=0.0001) were lower. The difference between children with SCA persisted after adjustment for haemoglobin (p=0.004). Urban Tanzanian children, with and without SCA, experience greater exposure to low daytime and night-time SpO2 compared with rural Kenyan children with SCA. Possible explanations include differences in the prevalence of obstructive sleep apnoea or asthma, alterations in the oxyhaemoglobin desaturation curve or cardiovascular compromise, for example, to shunting at atrial or pulmonary level secondary to increased pulmonary artery pressure. The fact that non-SCA siblings in the urban area are also affected suggests that environmental exposures, for example, air pollution, nutrition or physical exercise, may play a role. Further studies should determine aetiology and clinical relevance for the SCA phenotype in children resident in Africa.

Paediatric cerebral sinovenous thrombosis: findings of the International Paediatric Stroke Study.

OBJECTIVES: We evaluated clinical features, treatment practices and early outcome in a multicentre cohort of children with cerebral sinovenous thrombosis (CSVT). METHODS: Children with CSVT from 10 countries were enrolled from January 2003 to July 2007 in the International Paediatric Stroke Study. We analysed clinical symptoms, underlying conditions, antithrombotic treatment and neurological outcome at hospital discharge in 170 children. RESULTS: Of 170 children enrolled, 60% were male; median age 7.2 years (IQR 2.9-12.4). Headache, altered consciousness, focal deficits and seizures were common presenting clinical features. Infarction affected 37% and intracranial haemorrhage 31%. Risk factors included chronic disease in 50%; acute systemic illness or head/neck disorders 41%; prothrombotic state 20% and other haematological abnormality 19%. Discharge neurological status was normal in 48%, abnormal in 43% and unknown in 5%. Antithrombotic therapy was common, most often low molecular weight heparin was common, with significant regional variation in treatment practices. Mortality was low (4%) and was associated with no anticoagulation but not underlying chronic disease, anatomic extent of thrombosis or intracranial haemorrhage. Abnormal neurological status at discharge or death was associated with decreased level of consciousness at presentation and the presence of an identified prothrombotic state. CONCLUSIONS: Our study extends the observations of previously published smaller studies in children with CSVT that this is a morbid disease with diverse underlying causes and risk factors. Divergent treatment practices among highly specialised centres as well as limited data on treatment efficacy and safety suggest that further study of this condition is warranted.

MR perfusion imaging in Moyamoya Syndrome: potential implications for clinical evaluation of occlusive cerebrovascular disease.

BACKGROUND AND PURPOSE: Ischemic symptoms in patients with moyamoya syndrome (MMS) are usually due to hemodynamically mediated perfusion failure, and identification of abnormal tissue perfusion in these patients is therefore clinically important. Although dynamic susceptibility contrast (DSC) MRI can be used to study tissue perfusion, there are potential technical problems in MMS. This study investigates the scope and limitations of perfusion MRI in the clinical evaluation of such patients. METHODS: Thirteen patients with bilateral MMS were studied with the use of structural, diffusion, and perfusion MRI. The DSC MRI data were analyzed both visually and by a quantitative regional analysis, and the relationship between perfusion status and clinical symptoms was investigated. RESULTS: Extensive bilateral DSC MRI abnormalities were observed in all the patients. There was a very heterogeneous distribution of bolus arrival time. The areas of abnormality included the major arterial border zones in all cases, although these usually appeared normal on structural and diffusion MRI. Only the most clinically unstable patients had peak width (defined as time to peak minus bolus arrival time) >5 seconds on the quantitative regional analysis. Several technical limitations of perfusion quantification in MMS are described, as well as the implications of these limitations in patients with other forms of occlusive large-vessel disease. CONCLUSIONS: The technical limitations of DSC MRI described in this study are important for the accurate interpretation of perfusion MRI in MMS. Despite these limitations, these preliminary findings suggest that the use of quantitative regional analysis of summary parameters may provide clinically useful information in patients with MMS.

1H magnetic resonance spectroscopy in the investigation of intractable epilepsy.

We have been using proton magnetic resonance spectroscopy (1H MRS) in the investigation of adults and children with intractable epilepsy. Spectra were obtained from 2 x 2 x 2 cm cubes in the medial region of the temporal lobe, and were analyzed on the basis of signals from N-acetylaspartate (NAA), creatine+phosphocreatine (Cr), and choline-containing compounds (Cho). In comparison with control subjects, the epilepsy patients as a group show significant reductions in the NAA signal and in the NAA/Cho+Cr ratio, with increases in the Cho and Cr signals. The reduction in NAA is interpreted in terms of neuronal loss or damage, while the increase in Cr and Cho signals may be a reflection of reactive astrocytosis.

Posterior circulation stroke in childhood: risk factors and recurrence.

OBJECTIVE: To ascertain whether posterior circulation stroke in children has distinctive clinical or radiologic features. METHODS: Patients were identified retrospectively from two pediatric neurology centers. Clinical details were ascertained by chart review, and radiologic data were reviewed by three neuroradiologists. RESULTS: Twenty-two cases were identified (17 boys). Twenty children had evidence of vertebrobasilar arterial abnormalities, which were multifocal in 12. The etiology of these was vertebral artery dissection in 10 cases and unclear in the remaining 10. Cardiac abnormalities were rare (n = 4). Other risk factors for stroke in childhood were hypertension (n = 9), the thermolabile methylene tetrahydrofolate reductase gene mutation (n = 4), and the factor V Leiden mutation (n = 2). Two children had subluxation of the upper cervical spine at the extreme of normal limits. In follow-up for 6 months to 11 years (median 4 years), five patients had further strokes and seven had TIA. Overall, 12 patients had no residual neurologic deficits. CONCLUSIONS: The male preponderance, frequency of arterial dissection, rarity of cardiac embolism, and >20% recurrence were notable. Cerebral angiography is usually indicated if a definitive diagnosis is not made on MRI. Additional investigations should include echocardiography and cervical spine radiography in flexion and extension.

Measurement of cerebral blood flow during cardiopulmonary bypass with near-infrared spectroscopy.

OBJECTIVE: A novel noninvasive method for repeatedly measuring cerebral blood flow during cardiopulmonary bypass by near-infrared spectroscopy is described. The reproducibility of the method is investigated and a comparison is made with an established technique. METHODS AND RESULTS: The method is derived from the Fick principle and uses indocyanine green dye, injected into the bypass circuit, as an intravascular tracer. Cerebral blood flow was measured in nine children undergoing cardiopulmonary bypass on a total of 49 occasions. Results from this study suggest that an integrating period of 4 seconds provided a consistent measurement of global cerebral blood flow. The values obtained ranged from 3.2 to 32.4 (median 15.9) ml.100 gm-1.min-1. In an additional 10 children in whom repeated measurements were made, the coefficient of variation was 11% +/- 7% (mean +/- standard deviation). In a further study, the method was compared with microsphere injection in five piglets undergoing cardiopulmonary bypass. The comparison within each animal with the linear least squares method gave values for R2 in the range 0.91 to 0.99. The gradients of the fits ranged from 0.5 to 1.8 (median 1.0). The mean difference between the two techniques was 5.7 ml.100 gm-1.min-1 or 7%. The coefficient of variation for the piglets was 14% +/- 9% (mean +/- standard deviation). CONCLUSIONS: Indocyanine green and near-infrared spectroscopy allow frequent and repeated measurements of cerebral blood flow during cardiopulmonary bypass. The measurements are reproducible and accurately reflect changes in cerebral blood flow. It may be widely applicable both in research and clinical practice.

The relation between pump flow rate and pulsatility on cerebral hemodynamics during pediatric cardiopulmonary bypass.

OBJECTIVES: Neurologic impairment, at least partly ischemic in origin, has been reported in up to 25% of infants undergoing cardiopulmonary bypass, with or without circulatory arrest. Controversy continues about the effect of pump flow, pulsatile or nonpulsatile, on the brain and in particular on cerebral blood flow. This study examines the relationship between pump flow rate and cerebral hemodynamics during pulsatile and nonpulsatile cardiopulmonary bypass. METHOD: Near-infrared spectroscopy was used to determine cerebral blood flow and cerebral blood volume (measured as concentration change) in a randomized crossover study. Pulsatile and nonpulsatile flow were used for six 5-minute intervals at each of three different pump flow rates (0.6, 1.2, and 2.4 L x m2 x min(-1)) in 40 patients, median age 2 months (range 2 weeks to 20 years 5 months). The relations between pulsatile flow, pump flow rate, cerebral blood flow, hemoglobin concentration change (cerebral blood volume), mean arterial pressure, arterial carbon dioxide tension, and hematocrit value were prospectively examined by means of multivariate analysis. RESULTS: Cerebral blood flow decreased 36% per L x m(-2) x min(-1) decrease in pump flow rate and was associated with changes in mean arterial pressure but did not differ according to pulsatility. Change in hemoglobin concentration was unrelated to changes in pulsatility of pump flow. CONCLUSION: Cerebral blood flow is related to pump flow rate. Pulsatile flow delivered with a Stöckert pump does not increase cerebral blood flow or alter hemoglobin concentration during cardiopulmonary bypass in children.

Cerebral hemodynamics during cardiopulmonary bypass in children using near-infrared spectroscopy.

We describe a new noninvasive method using near-infrared spectroscopy for monitoring cerebral hemodynamics during cardiopulmonary bypass in children. All patients were undergoing open heart operations for repair of congenital heart defects. Standardized anesthesia, an alpha-stat method of blood gas management, and nonpulsatile flow were used in all cases. All measurements during bypass were made after steady-state conditions had been reached. Cerebral blood flow was measured on 13 occasions in 4 children, aged between 4 and 10 months (median, 5 months). Values of 15.9 to 53.5 mL x 100 g-1 x min-1 were obtained. Cerebral blood volume was measured in 1 patient, aged 4 months. Volumes of 4.3 to 8.0 mL x 100 g-1 were obtained on bypass at full pump flow (2.4 L.min-1 x m-2). On bypass at half flow, the volume increased to 14.7 mL x 100 g-1. Change in cerebral blood volume with changing carbon dioxide tension (CBVR) was measured in 13 patients aged from 1 to 90 months (median, 13.5 months). Preoperatively, CBVR was 0.12 +/- 0.07 mL x 100 g-1 x kPa-1 and was independent of mean arterial pressure, which remained between 40 and 80 mm Hg in all cases. During hypothermic bypass (25 degrees C), CBVR was significantly reduced to 0.05 +/- 0.02 mL x 100 g-1 x kPa-1. In addition, there were three values at mean arterial pressure of lower than 40 mm Hg in which CBVR was negative (-0.04 +/- 0.01 mL x 100 g-1 x kPa-1). We conclude that near-infrared spectroscopy is useful for the noninvasive investigation of cerebral hemodynamics during cardiopulmonary bypass.

Coma scales for children with severe falciparum malaria.

The Blantyre coma scale (BCS) is used to assess children with severe falciparum malaria, particularly as a criterion for cerebral malaria, but it has not been formally validated. We compared the BCS to the Adelaide coma scale (ACS), for Kenyan children with severe malaria. We examined the inter-observer agreement between 3 observers in the assessment of coma scales on 17 children by measuring the proportion of agreement (PA), disagreement rate (DR) and fixed sample size kappa (kappa n). We assessed the sensitivity and specificity of the scales in detecting events (seizures and hypoglycaemia) in 240 children during admission and the usefulness of the scales in predicting outcome. There was considerable disagreement between observers in the assessment of both scales (BCS: PA = 0.55, DR = 0.09 and kappa n = 0.27; ACS: PA = 0.36, DR = 0.31, and kappa n = 0.31), particularly with the verbal component of the BCS (kappa n = 0.02). Compared to the ACS, the BCS was more specific (0.85 for BCS and 0.80 for ACS), but less sensitive (0.25-0.69 vs. 0.38-0.88 respectively) in detecting events and was a worse predictor of neurological sequelae. The BCS provided a better overall assessment of a child's incapacity from falciparum malaria, but the ACS was more useful in assessing neurological disturbances.

Risk factors for arterial ischemic stroke in children.

Since early recurrence occurs in at least 10% of patients presenting with their first stroke in childhood in the reported series, the search for modifiable risk factors should be a priority. Risk factors for stroke in adults include hypertension, diabetes, and smoking, as well as cardiac disease and sickle cell anemia; asymptomatic cerebrovascular disease and transient ischemic events may predict stroke in this age group. The investigation of a child with a stroke has traditionally focused on finding a single cause rather than looking for risk factors to which the patient may be exposed life long. Approximately half of children presenting with stroke have a known predisposing condition, but some have unexpected pathologies such as primary cerebrovascular disease associated with congenital heart anomalies, or may have modifiable risk factors such as hypertension associated with sickle cell disease. The literature on children presenting with initially unexplained (cryptogenic) stroke suggests that there is a daunting list of possible causes, but since the series have mainly been small, it has been difficult to evaluate the relative importance of the reported associations. This paper reviews the literature on congenital, genetic, and acquired risk factors for stroke in childhood, and includes data from the large series of patients seen at Great Ormond Street Hospital over the past 10 years. The majority have arteriographic abnormalities and there is little evidence for asymptomatic cardiac disease. Genetic predisposition, trauma, infection, and nutritional deficiencies appear to be important, although case-control studies will be required to prove causation. Appropriate screening for modifiable risk factors may lead to prevention of recurrence in some patients. In the long term, an understanding of the multiple etiologies of childhood cerebrovascular disease and ischemic stroke may lead to primary prevention in this age group, and perhaps in adults.

Intelligence after stroke in childhood: review of the literature and suggestions for future research.

Review of published clinical and neuropsychologic outcome studies reveals limited information about intellectual functioning after childhood stroke. The extant data are supplemented here by analysis of intelligence quotient (IQ) results obtained from 38 children in an ongoing study of unilateral middle cerebral artery ischemic stroke. Evidence so far indicates that, after stroke, mean IQ falls significantly below the population mean but remains within the average range. There is no significant difference between hemispheric side of injury; the Verbal and Performance IQ lateralization profile widely recognized in adults with unilateral injury is not apparent in younger children, and there is only a trend toward this profile in older children. The effects of a number of other variables, including sex, site of stroke, and longitudinal assessment, are also considered. Although the generally minor effect of stroke on IQ is encouraging, a number of children do require extra help on return to school. Some suggestions for future research are highlighted in order to encourage further consideration of the issues raised here.

Idiopathic "benign" intracranial hypertension: case series and review.

Idiopathic "benign" intracranial hypertension is an uncommon but important cause of headache that can lead to visual loss. This study was undertaken to review our experience in the diagnosis and management of idiopathic intracranial hypertension, giving special attention to treatments used. A retrospective chart review was conducted on 32 patients diagnosed with idiopathic intracranial hypertension between 1984 and 1995. Subjects included 23 females and ranged in age from 2 to 17.5 years. Headache was the most common symptom, followed by nausea and vomiting, double vision, and visual loss. Papilledema was the most common sign. Others were VIth cranial nerve palsy and compromised visual acuity at or within 3 months of presentation. Management included administration of acetazolamide or corticosteroids, lumboperitoneal shunt, optic nerve fenestration, and repeat lumbar puncture. Treatment combinations were used in 40% of cases. During follow-up, headache, papilledema, and decreased visual acuity persisted for longer than 10 months in a significant number of patients. We conclude that idiopathic intracranial hypertension causes significant short- and long-term morbidity with no proven effective treatment available. A prospective study is needed to establish the indications for treatment and the efficacy of the treatments used.

Diffusion and perfusion magnetic resonance imaging in childhood stroke.

Two magnetic resonance imaging techniques, diffusion and perfusion imaging, are being used increasingly for evaluation of pathophysiology of stroke. This article introduces these techniques and reports some initial studies using these approaches, together with conventional T2-weighted magnetic resonance imaging, for investigation of childhood stroke. It is shown that the combination of T2-weighted and diffusion images can provide information about the timing of stroke events in childhood, and perfusion imaging can detect abnormalities not visible by other magnetic resonance imaging techniques. These magnetic resonance methods therefore should play an important role in investigation of children with stroke and could be of particular value in studies of at-risk populations of children such as those with sickle cell disease.

Cerebral blood volume response to changes in carbon dioxide tension before and during cardiopulmonary bypass in children, investigated by near infrared spectroscopy.

Neurological impairment may occur following cardiopulmonary bypass (CPB) and the effect of CPB on cerebrovascular control may be important in the mechanism of cerebral injury. We have used near infrared spectroscopy (NIRS) to observe cerebral haemodynamics non-invasively before and during CPB. We measured the change in cerebral blood volume (CBV) associated with changing PaCO2 (CBVR). Patients (n = 19) were aged from 1 to 135 (median 14) months. The cerebral blood volume response was determined pre-operatively at normothermia under the influence of standardised anaesthesia employing isoflurane (up to ET conc 0.5%) and during steady-state hypothermic bypass (22-32 degrees C) at an arterial pump flow rate of 1.9-2.4 lm-2.min-1. Complete data was available for 10 patients. The relation between CBV, arterial carbon dioxide tension (PaCO2), mean arterial pressure (MAP) and central venous pressure (CVP) was examined using analysis of covariance (P < or = 0.05) was accepted as significant). The change in CBV associated with changing PaCO2 was corrected for the effects of MAP and CVP. Preoperatively the median CBVR was 0.130 (25th-75th percentile 0.079-0.243) ml.100 g-1.kPa-1 and during hypothermic bypass the median CBVR was 0.093 (25th-75th percentile 0.026-0.255) ml.100 g-1.kPa-1. These values were compared with our reference range derived for normal conscious children using the Kruskal-Wallis test. There was not statistically significant difference between the three groups (P = 0.35). These results, indicating preservation of CBVR during the conditions of anaesthesia and bypass used, are consistent with the observations of previous authors who measured cerebral blood flow response to carbon dioxide by a variety of other methods. Near infrared spectroscopy is proving to be a reliable, non-invasive technique for the investigation of cerebral haemodynamics during CPB.