Magnetic resonance angiography in 140 neuropediatric patients

Perinatal arterial ischemic stroke: presentation, risk factors, evaluation, and outcome

BACKGROUND

Perinatal arterial ischemic stroke is as common as large vessel arterial ischemic stroke in adults and leads to significant morbidity. Perinatal arterial ischemic stroke is the most common identifiable cause of cerebral palsy and can lead to cognitive and behavioral difficulties that are amortized over a lifetime.

METHODS

The literature on perinatal arterial ischemic stroke was reviewed and analyzed.

RESULTS

Risk factors for perinatal arterial ischemic stroke include those that are maternal, neonatal, and placental. The most common clinical signs at presentation are seizures and hemiparesis. Evaluation should begin with thorough history acquisition and physical examination followed by magnetic resonance imaging of the brain, with consideration of magnetic resonance angiography of the head and neck, echocardiogram, and thrombophilia evaluation. Treatment beginning early to include physical, speech, and occupational therapies including constraint-induced movement therapy and close cognitive and developmental follow-up may be beneficial. Future treatments may include transcranial magnetic stimulation, hypothermia, and erythropoietin.

CONCLUSIONS

Perinatal arterial ischemic stroke comprises a group of arterial ischemic injuries that can occur in the prenatal, perinatal, and postnatal periods in term and preterm infants with different types of perinatal arterial ischemic stroke having different clinical presentations, risk factors, and long-term outcomes.

Circle of Willis abnormalities in children with neurofibromatosis type 1

BACKGROUND AND PURPOSE

The aim of the study was to assess anatomical variants and abnormalities in cerebral arteries on magnetic resonance angiography in 67 children with neurofibromatosis type 1 (NF1).

MATERIALS AND METHODS

The study included 67 children aged 9 months to 18 years (mean 6.6 years). Control group comprised 90 children aged 2-18 years (mean: 11.8 years). All patients were examined at 1.5T scanner.

RESULTS

We found cerebral arteriopathy (moyamoya disease) in one child (1.5%) in the study group. No aneurysms were found. Twenty-nine NF1 children (43.3%) had arterial anatomical variants. In 13 of them, more than one variant was diagnosed (44.8% of group with variants, 19.4% of study group). In control group, 19 children (21.1%) had variants, including four children with more than one variant (21% of group with variants, 4.4% of control group). Arterial variants were more common in NF1 patients compared with control group (p=0.026, binomial test for two proportions). Percentage of multiple variants was higher in study group than in control group, but this difference was not significant. Variants were more frequent on left side than on the right one (significant difference in control group; p=0.022, McNemara test). In study group, the number of left-sided anomalies (25) was similar to that of right-sided ones (22). There was no correlation between gender and variants, unidentified bright objects and variants or between optic gliomas and variants.

CONCLUSIONS

Occurrence of arterial variants in NF1 patients was twofold higher than in control group. Multiple variants were more frequent in the study group although the difference did not reach statistical significance. Features of cerebral arteriopathy were found in one child with NF1.

Anatomic changes and imaging in assessing brain injury in the term infant

Encephalopathy from hypoxic-ischemic injury is a major cause of morbidity and mortality in term infants. MRI is the gold standard in evaluating the nature and extent of injury. Although imaging this population is challenging, important information can be obtained safely. Patterns of injury and the likely mechanisms that cause them are reviewed. Conventional images combined with additional techniques provide clues to cause, timing, and long-term prognosis. As altering acute neurologic damage with interventions in the acute period becomes a reality, MRI will play a crucial role in delineating which infants have the most to gain and act as a biomarker to gauge response.

[Arterial stroke after birth trauma]

Perinatal arterial stroke is a significant cause of neurological deficit, including mental retardation, delayed motor development, epilepsy, and severe cognitive impairment. Most strokes occur in term neonates, due to thromboembolism from an intracranial or extracranial vessel associated with a risk factor such as asphyxia at birth and heart, hematological or infectious diseases. An association with instrumental delivery has not been clearly demonstrated, although several cases have been described in the literature. The incidence of stroke in the perinatal period is estimated to be 1/4000 term neonates per year. We describe three new cases of stroke in term neonates with instrumental delivery and describe the etiopathogenesis, diagnosis and outcome of this entity.

Magnetic resonance studies of brain lesions in patients with Kawasaki disease

We evaluated brain lesions in patients with coronary arterial lesions (CAL) as a complication of Kawasaki disease (KD) by magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA). Among 47 patients who underwent coronary angiography for the evaluation of CAL due to KD at Kyushu University Hospital from April 1996 to September 2004, 24 patients were evaluated prospectively by brain MRI and MRA 0.1-21.2 years after the onset of KD. Although most patients had irritability or lethargy, none of them had significant neurological symptoms or signs during the acute phase, except one who showed neck stiffness. In one patient with no apparent neurological symptoms out of the 24 patients, brain MRI and MRA revealed right cerebellar infarction and obliteration of the right posterior inferior cerebellar artery, respectively. These results revealed the presence of cerebrovascular lesion in one of the 24 KD patients with CAL and suggested the need to consider the possibility of brain lesions in severe cases of KD with or without neurological symptoms.

Epilepsy and destructive brain insults in early life: a topographical classification on the basis of MRI findings

Destructive insults of early development can lead to a wide variety of lesional patterns and are a well known cause of epilepsy. The aim of this study is to present a topographic magnetic resonance imaging (MRI) classification of these lesions in adult patients with epilepsy. Thirty-three consecutive patients were divided in three groups according to the topographic distribution of their lesion on MRI: hemispheric (H, n = 7); main arterial territory (AT, n = 18); arterial borderzone (Bdz, n = 8). We analyzed clinical, MRI and magnetic resonance angiography (MRA) data. Status epilepticus (SE) during childhood was more common in group H (7/7) than in the groups AT (1/18) and Bdz (0/8) (P < 0.001). MRA pattern of impaired flow signal in the distal segments of all three major arteries in the affected hemisphere was present in 85.7% of group H patients, and was exclusive to this group. 88.8% (16/18) of patients from group AT presented congenital motor deficit, in contrast to 37.5% (3/8) of group Bdz, and in none of group H (P < 0.001). All patients with Bdz lesions had antecedent of fetal distress, in contrast to 1/7 from group H and 5/18 of group AT (P = 0.001). The MRAs of patients with Bdz lesions were often normal except in those with larger lesions. Our data suggest that in adult patients with epilepsy due to precocious destructive brain insults, a MRI topographical classification distributes them in relatively homogenous clinical groups.

Stroke in newborn infants

The few days before and after birth are a time of special risk for stroke in both mother and infant, probably related to activation of coagulation mechanisms in this critical period. Arterial ischaemic stroke around the time of birth is recognised in about one in 4000 full-term infants, and may present with neurological and systemic signs in the newborn. Neonatal seizures are most commonly the clinical finding that triggers assessment. In other children, perinatal stroke is recognised only retrospectively, with emerging hemiparesis or seizures after the early months of life. Risk factors for perinatal stroke include hereditary or acquired thrombophilias and environmental factors. Perinatal stroke underlies an important share of congenital hemiplegic cerebral palsy, and probably some spastic quadriplegic cerebral palsy and seizure disorders. There is much to be learned about the natural history of perinatal stroke, and there are as yet no evidence-based strategies for prevention or treatment.

Cerebrovascular disorders in children

Cerebrovascular disorders are an important cause of mortality and chronic morbidity in children. International incidence rates for childhood stroke (ie, from 30 days to 18 years of age) have ranged from 1.3 to 13 per 100,000 children. Ischemic stroke is probably more common than hemorrhagic stroke in children. The clinical presentation of stroke in children varies according to age and location of the stroke. Over 100 risk factors for stroke in children have been reported, but in up to one third of cases no cause is identified. The management and prevention of stroke in children is not well studied and current recommendations are based on adult studies, nonrandomized trials, or expert opinion. Over half of children with stroke will develop lifelong cognitive or motor disability and up to one third will have a recurrent stroke. This review briefly describes the epidemiology, risk factors, evaluation, treatment, and outcome of stroke in children.

Magnetic resonance angiography in childhood arterial brain infarcts: a comparative study with contrast angiography

BACKGROUND AND PURPOSE

Contrast angiography (CA) is the reference examination for the diagnosis of cerebral arterial abnormality, but this procedure is invasive. In childhood, ischemic strokes are being increasingly investigated by means of MRI, including MR angiography (MRA). Very few data are available about the accuracy of MRA compared with CA in the specific context of acute pediatric stroke. We sought to compare the results of MRA with those of CA for the study of cerebral arteries in children with arterial infarction in an arterial distribution.

METHODS

Twenty-four children presenting with 26 infarcts were studied. All were examined with cerebral MRI and MRA and with CA. The interval between CA and MRA was <3 days for most of the patients.

RESULTS

Arterial lesions were detected in all but 2 children. They were located in the major cerebral arteries, predominantly in the anterior circulation (85% of cases). All lesions shown by CA were present on MRA (19 cases). Patients with no lesion on MRA had normal CA (2 cases). Associated distal vascular lesions and degree of arterial stenosis were more accurately detected with CA.

CONCLUSIONS

MRA is sensitive enough to provide an adequate initial evaluation of arterial brain disease in childhood.

Stroke in children: recognition, treatment, and future directions

Childhood stoke is increasingly recognized, but studies remain largely descriptive. Important differences from adult stroke include the following: (1) frequently delayed or missed diagnosis, (2) heterogenous and overlapping risk factors, and (3) developmental differences in the cerebrovascular, neurologic, and coagulation systems. These aspects limit the extrapolation of the results of adult stroke research and present challenges in caring for children with stroke. The incidence of childhood ischemic stroke exceeds 3.3 in 100,000 children per year, more than double the estimates from past decades. The increased incidence reflects, in part, increased survival in previously fatal conditions predisposing to stroke, including congenital heart disease, sickle cell anemia, and leukemia. Risk factors for stroke are recognized in more than 75% of children. Common risk factors include congenital heart disease and sickle cell disease. Progressive arteriopathies, including vasculitis and moyamoya syndrome, are rare in children with stroke; however, transient arteriopathies including post-varicella angiopathy are increasingly recognized. Prothrombotic abnormalities are frequently present but of unclear significance. Adverse outcomes after childhood stroke, including death in 10%, recurrence in 20%, and neurologic deficits in two thirds of survivors could be reduced with available stroke treatments. Aggressive prehospital emergency care and transfer could improve access to hyperacute stroke therapies including tPA. Currently, the diagnosis is delayed by more than 24 hours from onset in most children. As in adults, tPA will likely produce unacceptable rates of intracerebral hemmorrhage unless given within 3 hours of stroke symptom onset. The appropriate choices for in hospital treatment and secondary preventative strategies, including aspirin and anticoagulants, are controversial. Empiric recommendations are published; however, age-appropriate clinical trials are urgently needed. The large multinational networks of investigators necessary for designing and conducting these future trials are now being formed.

Comparison of MRI and MRA findings in children with a variety of neurologic conditions

The role of MRA in the evaluation of children is evolving. We compared MRA and MRI in children with a variety of neurologic conditions to determine when MRA provides positive, cost-beneficial information. A total of 114 patients were retrospectively studied. MRA and MRI were performed and compared. MRA was abnormal in 34 (30%) of 114 patients: five (83%) of six with Menkes' disease, four (33%) of 12 with sickle cell disease, 12 (38%) of 32 with vascular malformations, one (6%) of 17 with headaches, seven (24%) of 24 with new focal deficits, one (10%) of 10 with seizures, and four (31%) of 13 with miscellaneous diagnoses. MRA and MRI were concordant in 73 (64%) of 114. Maximum concordance was in patients with Menkes' disease (100%) and minimum in those with new focal deficits (50%). The best MRA cost/benefit ratios were obtained in patients with Menkes' disease, vascular malformations, and sickle cell disease. A normal MRI usually forecasted a normal MRA. However, abnormal MRI findings did not always predict MRA abnormalities. Positive, cost-beneficial information is provided by MRA mostly in conditions known to involve the cerebral vasculature. Indications to perform MRA should be based on the neurologic diagnosis and MRI findings.

Perinatal cortical infarction within middle cerebral artery trunks

AIM

To define neonatal pial middle cerebral artery infarction.

METHODS

A retrospective study was made of neonates in whom focal arterial infarction had been detected ultrasonographically. A detailed study was made of cortical middle cerebral artery infarction subtypes.

RESULTS

Forty infarctions, with the exception of those in a posterior cerebral artery, were detected ultrasonographically over a period of 10 years. Most were confirmed by computed tomography or magnetic resonance imaging. Factor V Leiden heterozygosity was documented in three. The onset was probably antepartum in three, and associated with fetal distress before labour in one. There were 19 cases of cortical middle cerebral artery stroke. The truncal type (n=13) was more common than complete (n = 5) middle cerebral artery infarction. Of six infarcts in the anterior trunk, four were in term infants and five affected the right hemisphere. Clinical seizures were part of the anterior truncal presentation in three. One of these infants, with involvement of the primary motor area, developed a severe motor hemisyndrome. The Bayley Mental Developmental Index was above 80 in all of three infants tested with anterior truncal infarction. Of seven patients with posterior truncal infarction, six were at or near term. Six of these lesions were left sided. Clinical seizures were observed in three. A mild motor hemisyndrome developed in at least three of these infants due to involvement of parieto-temporal non-primary cortex.

CONCLUSIONS

Inability to differentiate between truncal and complete middle cerebral artery stroke is one of the explanations for the reported different outcomes. Severe motor hemisyndrome can be predicted from neonatal ultrasonography on the basis of primary motor cortex involvement. Clinical seizures were recognised in less than half of the patients with truncal infarction; left sided presentation was present in the posterior, but not the anterior truncal type of infarction. Asphyxia is a rare cause of focal arterial infarction.

Neonatal brain tumors: a review

This article presents two cases of infants with brain tumors and reviews the literature pertinent to congenital and neonatal brain tumors. Information regarding epidemiology, presentation, prognosis, and clinical management are also addressed with specific regard to differences between neonatal and childhood brain tumors. An appeal is made to consider (1) coordination of the care of these children through pediatric multidisciplinary neuro-oncology programs; (2) enrollment, whenever possible, in clinical trials; and (3) submission of available tumor tissue to pediatric tumor banks to assure its availability to interested researchers.

Ischemic strokes in children

Ischemic stroke is an uncommon, but significant cause of disability in childhood. Children with strokes present with predictable deficits as adults do; however, fever and seizures at stroke onset are more common in children than in adults. Strokes in children have diverse etiologies and require extensive evaluation. Etiology remains obscure in up to half of the patients. Prognosis in childhood stroke is not benign and up to 50% of pediatric stroke patients have chronic sequelae. Emerging therapies may alter prognosis in certain populations of children at risk for stroke, but more research is necessary.

Ischemic cerebrovascular disease in children: retrospective study of 35 patients

A 10-year review of a neuropediatric department experience with childhood ischemic cerebrovascular disease identified 35 patients with arterial ischemic stroke. The ability to diagnose stroke in children has improved with the development of imaging techniques in the past few years. Children have a wide array of risk factors for ischemic strokes, since some are acquired and others are congenital. Twenty-eight associated conditions (80%) were found in our patients and we identified 17 specific causes (48.5%) among them. The cause of stroke in children is important to recognize because stroke is likely to recur depending on the etiology.