Basal ganglia and thalamic infarction in children. Cause and clinical features

Post-traumatic ischaemic stroke in a teenager after head trauma: A case report

Background

Lacunar strokes in the pediatric population are very uncommon, as well as trauma-induced strokes. It is extremely rare for a head trauma induced ischaemic stroke to occur in children and young adults.

Case report

We describe a case of a 13-year-old boy who reported acute ischaemic lesions, and in particular a right basal ganglia ischaemic stroke after falling from a height of 10 m, presumably secondary to the stretching-induced occlusion of the recurrent artery of Heubner, with a favorable outcome.

Conclusion

Ischaemic strokes can rarely be subsequent to head trauma in young adults, in relationship with the degree of maturity of the perforating vessels. Although very rare, it is important to avoid the lack of recognition of this condition, thus awareness is necessary.

Lyme Neuroborreliosis - The Mystifying Pitfall: "Neuropathology and Current Therapeutics"

Lyme's Disease (LD) is a severe, rapidly growing, broad spectrum chronic infection caused by the bacterium 'Borrelia (B.) burgdorferi', which can be easily transmitted through the bite of certain species of ticks. The prevalence of LD is swiftly mounting in the present scenario in many countries from species to species. Although Lyme's infection is now detectable via serologic examination of early and late Lyme neuroborreliosis (LNB), the management of persistent symptoms is still fraught with quora of doubt and debate. LD is a multisystem spirochete which results after the dissemination of B. burgdorferi from a dermal inoculation site after a tick bite. Lyme's infection can easily get transmitted to the central nervous system and develop various neurological symptoms due to inflammation and an autoimmune response from body may lead to life-threatening "Lyme Borreliosis". The neurological symptoms are well mixed in presentation, late and confusing to get differentiated easily from other diseases. The use of antibiotics in post Lyme infection with neurological complications is still a topic of debate. Babesiosisstates, and human ehrlichiosis' the two other diseases, are associated with the same ticks that spread the LD. However, the prevalence of diagnosed human cases is usually much lower than that of actual cases of LD due to misdiagnosis, late diagnosis or undiagnosis at y such lateral neuroinfection stage after the tick bite. The current review focuses on the molecular neuropathology and current advancements in LD. There are very few patents or discoveries made on borrelia infection, drawing attention towards more focused and targeted research for the cure.

Neurodevelopmental outcome after neonatal perforator stroke

AIM

To assess outcome after neonatal perforator stroke in the largest cohort to date.

METHOD

Survivors from a cohort of children diagnosed with neonatal perforator stroke using cranial ultrasound or magnetic resonance imaging were eligible for inclusion. Recovery and Recurrence Questionnaire score, presence of cerebral palsy (CP), and crude outcome were assessed, specifically (1) the ability to walk independently, (2) participation in regular education, and (3) the presence of epilepsy.

RESULTS

Thirty-seven patients (20 males, 17 females) aged 3 to 14 years (mean age 8y) were included in the study: 14 with isolated single perforator stroke, four with multiple isolated perforator strokes, and 19 with additional brain injury. Out of 18 children with isolated perforator stroke(s), four had CP, one could not walk independently, and one developed epilepsy. The posterior limb of the internal capsule was involved in four out of 18 patients; three of these patients had CP. Of 19 children with additional brain injury, 11 had CP and three were not able to walk independently. Three out of nine children with concomitant cortical middle cerebral artery stroke developed epilepsy.

INTERPRETATION

Perforator stroke patterns can be of use in predicting long-term outcome and for guiding counselling and surveillance. Motor outcome was favourable in children with isolated perforator stroke(s), except when the posterior limb of the internal capsule was involved.

Lacunar stroke in a teenager after minor head trauma: case report and literature review

Ischemic strokes in children and young adults are fortunately rare. Contrasted with adult ischemic strokes, pediatric stroke etiologies vary greatly and are often unknown. Childhood lacunar strokes and trauma-induced strokes represent particularly uncommon subsets and have been reported infrequently in the literature. It is unique to find a combination of the 2-a lacunar stroke induced by trauma. Underreporting of these trauma-induced ischemic strokes could be responsible for perpetuating the lack of recognition. Here we present a lacunar stroke in a young woman associated with a water sport accident and explore relevant literature encircling deep brain ischemia coinciding with trauma.

Chronic or late lyme neuroborreliosis: analysis of evidence compared to chronic or late neurosyphilis

Whether spirochetes persist in affected host tissues and cause the late/chronic manifestations of neurosyphilis was the subject of long-lasting debate. Detection of Treponema pallidum in the brains of patients with general paresis established a direct link between persisting infection and tertiary manifestations of neurosyphilis. Today, the same question is in the center of debate with respect to Lyme disease. The goal of this review was to compare the established pathological features of neurosyphilis with those available for Lyme neuroborreliosis. If the main tertiary forms of neurosyphilis also occur in Lyme neuroborreliosis and Borrelia burgdorferi can be detected in brain lesions would indicate that the spirochete is responsible for the neuropsychiatric manifestations of late/chronic Lyme neuroborreliosis. The substantial amounts of data available in the literature show that the major forms of late/chronic Lyme neuroborreliosis (meningovascular and meningoencephalitis) are clinically and pathologically confirmed. Borrelia burgdorferi was detected in association with tertiary brain lesions and cultivated from the affected brain or cerebrospinal fluid. The accumulated data also indicate that Borrelia burgdorferi is able to evade from destruction by the host immune reactions, persist in host tissues and sustain chronic infection and inflammation. These observations represent evidences that Borrelia burgdorferi in an analogous way to Treponema pallidum is responsible for the chronic/late manifestations of Lyme neuroborreliosis.Late Lyme neuroborreliosis is accepted by all existing guidelines in Europe, US and Canada. The terms chronic and late are synonymous and both define tertiary neurosyphilis or tertiary Lyme neuroborreliosis. The use of chronic and late Lyme neuroborreliosis as different entities is inaccurate and can be confusing. Further pathological investigations and the detection of spirochetes in infected tissues and body fluids are strongly needed.

Dystonia and tremor secondary to a pediatric thalamic stroke

A previously healthy 10-year-old girl developed a right hemiparesis with sensory loss secondary to a posterolateral thalamic infarct. Despite improvement in strength, three weeks later a 4 Hz kinetic tremor appeared in the right hand accompanied by dystonia in the right upper and lower limbs. Basal ganglia vascular lesions are rare in childhood and movement disorders secondary to such lesions even more so. A thorough work-up failed to disclose the etiology. Our patient illustrates that dystonia and tremor secondary to posterolateral thalamic infarctions are also apt to occur in children and, unlike the adult picture, abnormal movements may develop very soon after the insult.

Pathophysiological role of inflammatory molecules in paediatric ischaemic brain injury

Ischaemic stroke is one of the major causes of death and lifelong disability also in the paediatric population. Strong scientific effort has been put to clarify the pathophysiology of this disease in adults. However, only few studies have been performed in children. Preliminary results indicate that pathophysiological processes might differently affect the poststroke neuronal injury in neonates as compared to children. During the neural development, selective molecular mechanisms might be differently triggered by an ischaemic insult, thus potentially resulting in defined postischaemic clinical outcomes. Basic research studies in neonatal animal models of cerebral ischaemia have recently shown a potential role of soluble inflammatory molecules (such as cytokines, chemokines and oxidants) as pivotal players of neuronal injury in both perinatal and childhood ischaemic stroke. Although larger clinical trials are still needed to confirm these preliminary results, the potential benefits of selective treatments targeting inflammation in perinatal asphyxia encephalopathy might represent a promising investigation field in the near future. In this review, we will update evidence on the pathophysiological role of soluble inflammatory mediators in neonatal and childhood ischaemic stroke. Recent evidence on potential anti-inflammatory treatments to improve paediatric stroke prognosis will be discussed.

Unilateral Basal Ganglia Infarcts: a Red Flag for Ipsilateral Cranio-Cervical Arterial Occlusive Disease. A Report on Two Children with Moya-moya Disease

Steno-occlusive disease of the internal carotid arteries and/or the circle of Willis with development of collateral perforator vessels attempting to supply under-perfused parenchyma are the basis for moya-moya phenomenon with the classic "puff of smoke" appearance on cerebral angiogram. We describe two cases of moya-moya with unilateral macroangiopathy of the internal carotid artery and ipsilateral middle cerebral artery in two 11-year-old girls: a Down's syndrome patient, and a second idiopathic patient. The arteriopathy in our cases differs from typical or classically described moya-moya disease in that it was exclusively unilateral rather than symmetric and bilateral. The association of predominant deep grey matter (basal ganglia) strokes in children with coexisting ipsilateral parainsular infarcts, as in our cases, is potentially a red flag for ipsilateral macroangiopathy.

Thalamic infarct presenting as apparent life-threatening event in infants

Thalamic infarction with distinct manifestations is well-described in adults but less well-delineated in children. We report two infants who presented with an apparent life-threatening event (ALTE) with very early magnetic resonance imaging (MRI) demonstrating a unilateral thalamic infarction. Subsequent MRI demonstrated bilateral changes in the brain stem and basal ganglia, which were in keeping with profound hypoxic ischaemic injury. We propose the thalamic infarction to be the primary event precipitating a profound hypoxic ischaemic injury as an alternative explanation to the neuroimaging observation.

CONCLUSION

Thalamic infraction may have a causal role in ALTE. Early and appropriate neuroimaging is required to detect these changes.

Childhood stroke in Eastern Province, KSA: pattern, risk factors, diagnosis and outcome

BACKGROUND AND PURPOSE

Stroke has been increasingly recognized in children in recent years, but diagnosis and management can be difficult because of the diversity of underlying risk factors, atypical presentation and the absence of a uniform treatment approach. The aim of this study was to examine risk factors, clinical presentation, imaging findings and outcomes of paediatric stroke in Eastern Province, Kingdom of Saudi Arabia (KSA).

SUBJECTS AND METHODS

We evaluated 25 patients (11 boys and 14 girls) using computerized tomography scan of the brain, magnetic resonance (MR) imaging and MR angiography. Cardiac assessment, haematological tests, immunological tests, infection and metabolic screening were also performed in the patients. After discharge, the patients were monitored regularly in the neurology clinic to detect their outcomes.

RESULTS

A total of 76% of the patients presented with ischaemic stroke, while the remaining 24% had haemorrhagic stroke. Sickle cell disease (SCD) was the commonest risk factor for stroke (36%) followed by non determinate causes (20%). Seizure was the commonest clinical presentation (54%) followed by haemiplegia (31%) and decreased level of consciousness (30%). Recurrence occurred in SCD patients (80%) and patients with moyamoya disease (20%). Regarding the outcome, long-term deficit was the commonest (44%), while short-term deficit and death were equal (28% each).

CONCLUSION

Our study in Eastern Province, KSA, showed agreement with other studies regarding risk factors, clinical presentation, imaging features and outcomes of stroke in children, yet with some points of differences, which are as follows: (1) SCD is the commonest risk factor in our study population, while in Chinese study it was not, (2) The percentage of cardiac disorders as a risk factor in this study was less than that in the European and American studies, and (3) there was relative discrepancy regarding predictors of outcome.

Cerebral infarction and neurodevelopmental outcome in childhood tuberculous meningitis

INTRODUCTION

Cerebral infarction is an important cause of neurological sequelae in childhood tuberculous meningitis (TBM).

AIM

To investigate neurodevelopmental outcome and development of motor sequelae in TBM-related cerebral infarction.

METHODS

A group of 64 children with TBM and computerized tomographic (CT) evidence of infarction were compared with regard to motor sequelae and neurodevelopmental outcome, with 54 children with TBM but no radiological evidence of infarction. The association between infarct number, size, location and outcome was investigated in the infarct group. Selected covariates were entered into a multivariate model to better understand the independent contribution of each factor on neurodevelopmental outcome.

RESULTS

An association was found between the presence, number and size of hemispheric infarcts and motor handicap on follow-up. Location of single basal ganglia infarcts, however, did not correlate with motor outcome. The Griffiths general developmental quotient (GQ) was significantly lower in children with bilateral (p<0001) and unilateral multiple infarcts (p=0.0239) compared to those without infarcts. The GQ of children with unilateral single infarcts was not significantly lower than those without infarction (p=0.2282).

CONCLUSION

Infarct characteristics should be taken into account when neurodevelopmental outcome is prognosticated in TBM. Young age, unilateral multiple or bilateral infarction on CT at 1 month, advanced stage of TBM and the interaction term stage x Glasgow coma score are the best predictors of neurodevelopmental outcome at 6 months.

Basal ganglia and internal capsule stroke in childhood--risk factors, neuroimaging, and outcome in a series of 28 patients: a tertiary hospital experience

We present 28 patients with basal ganglia ischemic stroke and describe the main neurological manifestations, neuroimaging findings, risk factors, and outcome. In 23 cases, at least 1 risk factor was identified. A total of 7 cases (25%) had antecedent of varicella infection and 7 cases (25%) had preceding mild head trauma. Similar antecedents were present only in 2.6% and 5.3% of patients with nonbasal ganglia stroke, respectively (odds ratio: 12.2, 95% confidence interval: 2.04-124.65 and odds ratio: 5.92, 95% confidence interval: 1.32-29.7). The arterial abnormalities identified in 10 patients were narrowing (6) or occlusion (4) of the M1 segment. After a median follow-up of 24 months, 19 patients had a good outcome. Magnetic resonance angiography and catheter cerebral angiography played an important role in the identification of arterial disease. We propose that basal ganglia infarction is a different group of ischemic stroke with prevalent risk factors (varicella infection and mild head trauma) and good outcome.

Bilateral paramedian thalamic and mesencephalic infarcts in a newborn due to occlusion of the artery of Percheron

Bilateral paramedian thalamic and mesencephalic infarcts are infrequently reported in adults, and to our knowledge, has never been reported in a child. The presumed etiology is an occlusion of the artery of Percheron, an uncommon vascular variation, in which a single common trunk from one of the P1 segments of the posterior cerebral artery provides bilateral irrigation to the paramedian thalami and midbrain. Bilateral paramedian thalamic and mesencephalic infarcts in adults are associated with symptoms of decreased arousal, vertical gaze paresis, mood changes, and memory difficulties. Although some improvement of these symptoms does occur, complete recovery is rare. We present here a full-term male neonate, whose right-hand sided clonic seizures on day-of-life 2 prompted neuroimaging, which revealed bilateral paramedian thalamic and mesencephalic infarcts, suggestive of an occlusion of the artery of Percheron.

Unilateral venous thalamic infarction in a child mimicking a thalamic tumor

Unilateral thalamic infarction is a rare condition in adults. This is a case report of a young child presenting with left-sided hemiparesis of sudden onset due to an unilateral venous thalamic infarction. This was attributed to an asymmetric thrombosis of the cerebral internal veins, a partial thrombosis of the vein of Galen and straight sinus. Magnetic resonance imaging resulted primarily in the differential diagnosis of a cerebral tumor or an intracerebral abscess, leading to stereotactic puncture. Subsequent magnetic resonance venography facilitated the correct diagnosis. Heparin-induced thrombocytopenia necessitated anticoagulation treatment with hirudin and later, warfarin. The patient made a complete recovery. We conclude that unclear unilateral thalamic lesions might be symptomatic of a cerebral deep venous thrombosis and might mimic a thalamic tumor. In uncertain cases, we suggest rapid performance of magnetic resonance angiography.

Clinical features, topographic patterns on DWI and etiology of thalamic infarcts

Thalamic infarcts may lead to diverse neurological disturbances, which easily results in misdiagnosis. Diffusion-weighed magnetic resonance imaging (DWI) is sensitive for the early diagnosis of the infarct and identification of the territory involved. The aim of this study was to analyze the clinical features, topographic appearance on DWI and etiology of thalamic infarcts. We reviewed clinical data, vascular risk factors, topographic patterns and etiology of thalamic infarcts. The patients were divided into 2 groups according to DWI patterns: isolated thalamic infarcts (ISO-TH) and combined thalamic infarcts (COM-TH). The former were further subdivided into 2 subgroups: inferolateral isolated thalamic infarcts (INF-TH) and non-inferolateral isolated thalamic infarcts (NON-INF) according to the vascular territories. The Patients were also divided according to etiology based on TOAST classification. The association of clinical features, DWI patterns and etiology was analyzed. Twenty nine patients were included, among which, 23 (79.3%) were ISO-TH and 6 (20.7%) were COM-TH. The most common territory involved in the ISO-TH was inferolateral territory [n=17 (73.9%)], followed by tuberothalamic artery territory [n=3 (13.0%)], and posterior choroidal artery territory [n=2 (8.7%)]. In COM-TH, the most common territory also was the inferolateral territory (n=3), followed by posterior choroidal artery territory (n=1). In 2 patients, the lesions involved more than one vascular thalamic territory. Significant association between small-vessel occlusion (SVO) and ISO-TH (INF-TH+NON-IFN) infarcts were found. Our study suggested that SVO was more prevalent in ISO-TH, and COM-TH needed more etiological examination. DWI might provide meaningful clues about etiology of thalamic infarcts.

Lacunar stroke and masked hypertension in an adolescent male

Hypertension has not been strongly identified as a risk factor in childhood stroke. This report describes a case of a teenager with a lacunar stroke, the type often observed in adults with hypertensive-associated infarction, and masked hypertension. The patient had normal blood pressure on initial presentation, but on further investigation demonstrated ambulatory hypertension with evidence of hypertensive end-organ damage. This case suggests that hypertension may be a risk factor in children with stroke, especially in cases of lacunar infarct. Evaluation for possible hypertension should be undertaken thoroughly to identify children who may benefit from antihypertensive therapy and therefore, prevent recurrences.

Aphasia owing to subcortical brain infarcts in childhood

The aim of this study was to further define the clinical features of subcortical aphasia in children with deep brain infarcts and to define the sequelae associated with childhood strokes. We retrospectively studied nine children with left subcortical brain infarcts who presented with acquired language disorder and underwent language investigations based on standardized tests. Stroke in these patients involved the left internal capsule, lenticular or thalamic nuclei, or a combination of these. Early aphasic manifestations following the deep cerebral infarcts affected language expression. These included mutism, nonfluent speech, word finding difficulties, and phonemic and semantic paraphasia. Speech comprehension was generally more preserved. All patients subsequently improved, although variably; sequelae such as dysfluency, word finding difficulties, and written language learning impairment could be detected through standardized tests in six of them (all younger than 6 years at the time of the infarct). Two of the three remaining patients (both older than 6 years at the time of the infarct) had a full recovery. Our study confirms the concept of childhood subcortical aphasia, depicts the linguistic profile in these patients, and sustains the indication of systematic formal language assessment during the follow-up of all children with subcortical infarct involving the dominant hemisphere.

Magnetic resonance image correlates of hemiparesis after neonatal and childhood middle cerebral artery stroke

OBJECTIVE

Motor impairment after neonatal and childhood-onset ischemic stroke (IS) is common, although the prevalence and type of hemiparesis differs between the 2 age groups. Lesion topography is an important predictor of hemiparesis after neonatal IS, but it is not known if the same topographic predictors of adverse motor outcome apply to childhood-onset IS. We used a consistent approach to define lesion topography and evaluate motor outcome in both age groups to (1) investigate whether early topographic predictors of hemiparesis after unilateral middle cerebral artery-territory stroke are the same in neonates and older children and (2) compare the prevalence of dystonia and loss of independent finger movements between the 2 age groups.

DESIGN

Twenty-eight patients with neonatal-onset IS (Hammersmith Hospital, London, United Kingdom) were studied together with 43 patients with childhood-onset IS (Great Ormond Street Hospital, London, United Kingdom). All patients had exclusive unilateral middle cerebral artery-territory IS. Lesion topography was studied by using the first magnetic resonance image acquired after the onset of symptoms and was coded for involvement of cerebral cortex (CC), posterior limb of the internal capsule (PLIC), basal ganglia (BG), and white matter. The primary outcome was hemiparesis, and secondary outcomes were dystonia and loss of age-appropriate independent finger movements.

RESULTS

Hemiparesis was more common after childhood-onset IS (56%) than neonatal-onset IS (24%). In neonatal-onset IS, concomitant involvement of BG, CC, and PLIC predicts the development of hemiparesis (odds ratio: 99; 95% confidence interval: 5.2-1883.8), and no child with 1 or 2 of these structures involved developed hemiparesis. In contrast, in childhood-onset IS, concomitant BG, CC, and PLIC lesions tended to be associated with hemiparesis (9 of 11), but this adverse outcome was seen also among patients with 1- or 2-site involvement. However, hemiparesis was less likely if the infarction involved BG only (odds ratio: 0.162; 95% confidence interval: 0.036-0.729). Dystonia was present in 15 of 24 in the childhood-onset group with hemiparesis but was not seen after neonatal-onset IS. In both age groups upper-limb impairment was more severe than lower-limb impairment, with frequent loss of independent hand function among hemiparetic patients.

CONCLUSIONS

In neonatal and childhood-onset IS, early magnetic resonance imaging provides useful prognostic information about subsequent motor outcome. There are differences in the functional response of the neuromotor system to injury between the 2 age groups that cannot be attributed to methodological differences alone.

The clinical outcomes of neonatal and childhood stroke: review of the literature and implications for future research

A detailed assessment of clinical outcomes after ischemic stroke in childhood is necessary to evaluate prognostic factors. Previous studies are difficult to compare because of differences in test instruments, study design, heterogeneity of cohorts and number of included cases. Depending on neurodevelopmental assessment methods, major and subtle/minor disabilities, especially in infants, may not have been detected. Most outcome studies reveal only limited information about behavioral changes and quality of life in children with ischemic stroke. Thus the assumption that children make a better recovery from stroke than adults due to the immature brain's capacity to reorganize function is not evidence-based. We systematically review the current literature with regard to the neurological and psychosocial development of affected children as well as their quality of life. Implications for future research strategies follow the review to encourage further clinical study of the neurobehavioral trajectory of childhood stroke.

Radiological approach to disorders of arterial brain vessels associated with childhood arterial stroke-a comparison between MRA and contrast angiography

Recent studies of arterial ischaemic stroke in children have emphasised the higher frequency of cerebral arterial abnormalities than believed previously, explaining some of the strokes thought to have been idiopathic. Moreover, recurrent strokes are significantly more frequent in children with multiple risk factors, including those with demonstrable vascular abnormalities. Thus, cerebral arterial imaging is essential for the understanding and therapeutic approach to this pathology. Contrast angiography (CA) is the reference examination for the diagnosis of cerebral arterial abnormalities, but MR angiography (MRA) is a sensitive and non-invasive method to evaluate the vasculopathy of childhood stroke. In this article we highlight recent data concerning localisation and characterisation of arterial lesions and discuss the yield of MRA compared with CA.

Vascular syndromes of the thalamus

BACKGROUND

This article reviews the anatomy, connections, and functions of the thalamic nuclei, their vascular supply, and the clinical syndromes that result from thalamic infarction.

SUMMARY OF REVIEW

Thalamic nuclei are composed of 5 major functional classes: reticular and intralaminar nuclei that subserve arousal and nociception; sensory nuclei in all major domains; effector nuclei concerned with motor function and aspects of language; associative nuclei that participate in high-level cognitive functions; and limbic nuclei concerned with mood and motivation. Vascular lesions destroy these nuclei in different combinations and produce sensorimotor and behavioral syndromes depending on which nuclei are involved. Tuberothalamic territory strokes produce impairments of arousal and orientation, learning and memory, personality, and executive function; superimposition of temporally unrelated information; and emotional facial paresis. Paramedian infarcts cause decreased arousal, particularly if the lesion is bilateral, and impaired learning and memory. Autobiographical memory impairment and executive failure result from lesions in either of these vascular territories. Language deficits result from left paramedian lesions and from left tuberothalamic lesions that include the ventrolateral nucleus. Right thalamic lesions in both these vascular territories produce visual-spatial deficits, including hemispatial neglect. Inferolateral territory strokes produce contralateral hemisensory loss, hemiparesis and hemiataxia, and pain syndromes that are more common after right thalamic lesions. Posterior choroidal lesions result in visual field deficits, variable sensory loss, weakness, dystonia, tremors, and occasionally amnesia and language impairment.

CONCLUSIONS

These vascular syndromes reflect the reciprocal cerebral cortical-thalamic connections that have been interrupted and provide insights into the functional properties of the thalamus.

Cerebral infarctions in the fetus and neonate: maternal-placental-fetal considerations

Historical data, clinical examination findings, and laboratory information must be integrated along a variable timeline that includes antepartum, intrapartum, and postnatal time periods when cerebral infarction can occur, in the context of the neonates genetic endowment. Genetic susceptibility or prenatal acquired vulnerabilities regarding stroke syndromes may set in motion a cascade of molecular pathways that ultimately cause or exacerbate brain injury when the vulnerable child experiences adverse medical conditions. The clinician must consider maternal, placental, and fetal conditions on which a stroke syndrome may be superimposed, with or without additional brain injury from other pathogenic mechanisms. Evaluation of fetal and neonatal cerebral infarction requires knowledge of mechanisms of brain injury that cross medical disciplines and may involve consultation with maternal/fetal specialists, placental and pediatric pathologists, neonatologists, geneticists, and other pediatric subspecialties. Comprehensive evaluations of survivors of cerebral infarction are needed to better understand structural and functional plasticity of the developing brain after a cerebrovascular event in the fetal and neonatal periods.

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.

A 15-year-old boy with central nervous system vasculopathy presenting with dysarthria-clumsy hand syndrome

Dysarthria-clumsy hand stroke syndrome has been described frequently in adults but not in children. We report a 15-year-old right-handed boy with sudden onset of dysarthria, dysphagia, right facial weakness, and mild right-hand clumsiness. Computed tomographic scan and magnetic resonance imaging demonstrated infarction in the genu and posterior limb of the left internal capsule. Magnetic resonance angiography and conventional angiography demonstrated stenosis of the supraclinoid portion of the left internal carotid artery and the origin of the left ophthalmic artery. Lacunar infarction in an older adult is not the only mechanism leading to dysarthria-clumsy hand syndrome.

Chickenpox and stroke in childhood: a study of frequency and causation

BACKGROUND AND PURPOSE

The purpose of this study was to determine whether infection with varicella is causal for arterial ischemic stroke (AIS) in children.

METHODS

First, a prospective cohort study was conducted in young children (aged 6 months to 10 years) with AIS at 2 institutions (cohort study). The presence of varicella infection <12 months before AIS was determined and compared with the published frequency of varicella infection in the healthy pediatric population. The clinical and radiographic features of AIS were compared between the varicella and nonvaricella study cohorts. Second, a literature search of varicella-associated AIS was conducted, and the clinical and radiographic features were compared with the study nonvaricella cohort.

RESULTS

In the cohort study, 22 (31%) of 70 consecutive children with AIS had a varicella infection in the preceding year compared with 9% in the healthy population. Children in the varicella cohort were more likely to have basal ganglia infarcts (P<0.001), abnormal cerebral vascular imaging (P<0.05), and recurrent AIS or transient ischemic attacks (P<0.05) than those in the nonvaricella cohort. The pooled literature analysis of 51 cases of varicella-associated AIS showed similar findings to the varicella cohort.

CONCLUSION

In young children with AIS, there is a 3-fold increase in preceding varicella infection compared with published population rates, and varicella-associated AIS accounts for nearly one third of childhood AIS. Varicella-associated AIS has characteristic features, including a 2-fold increase in recurrent AIS and transient ischemic attacks. Varicella is an important risk factor for childhood AIS.

Etiology of stroke in children

Although the risk factors for stroke in children are numerous and differ greatly from the causes of stroke in adults, a thorough diagnostic evaluation can identify one or more risk factors in most patients. Cardiac disorders and hemoglobinopathy are the most common causes of ischemic infarction, whereas various congenital anomalies of the blood vessels or defects in coagulation or platelet function are often found in children with intraparenchymal hemorrhage. More than one risk factor is commonly identified, especially in children with dural venous thrombosis. Identification of the underlying risk factors for cerebrovascular disorders in children is important because many of the risk factors can be treated, reducing the risk of subsequent strokes.

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.

Primarily chronic and cerebrovascular course of Lyme neuroborreliosis: case reports and literature review

As part of an ongoing study aiming to define the clinical spectrum of neuroborreliosis in childhood, we have identified four patients with unusual clinical manifestations. Two patients suffered from a primarily chronic form of neuroborreliosis and displayed only non-specific symptoms. An 11 year old boy presented with long standing symptoms of severe weight loss and chronic headache, while the other patient had pre-existing mental and motor retardation and developed seizures and failure to thrive. Two further children who presented with acute hemiparesis as a result of cerebral ischaemic infarction had a cerebrovascular course of neuroborreliosis. One was a 15 year old girl; the other, a 5 year old boy, is to our knowledge the youngest patient described with this course of illness. Following adequate antibiotic treatment, all patients showed substantial improvement of their respective symptoms. Laboratory and magnetic resonance imaging findings as well as clinical course are discussed and the relevant literature is reviewed.

Stroke in Children

Identification and treatment of the underlying risk factors for stroke reduce the potential for additional strokes; therefore, a thorough search for treatable risk factors is justified. Because some risk factors can have a cumulative effect, even children with known risk factors for stroke sometimes need to be evaluated for other conditions. Cerebral angiography is often helpful; I recommend angiography in any child with an unexplained infarction or hemorrhage. Angiography is especially important in children with intraparenchymal hemorrhage because more than one third of such children will prove to have some type of potentially treatable congenital vascular anomaly such as an arteriovenous malformation (AVM) or aneurysm. The evidence that periodic blood transfusion effectively prevents cerebral infarction due to sickle cell disease is compelling. Transfusions apparently must be continued indefinitely to maintain the reduction of stroke risk, and without iron chelation, chronic transfusion eventually results in severe iron toxicity and, most likely, death, so the decision to begin transfusion is not an easy one. Measurement of the time-averaged mean flow velocity in the large cerebral vessels with transcranial Doppler (TCD) is highly predictive of stroke risk in these children, enough to justify its routine use in screening patients with sickle cell disease for stroke risk. I believe that patients with sickle cell disease should be offered chronic transfusion after an initial large-vessel stroke or when the TCD results suggest a high risk of stroke. The family must be made aware of the serious complications of chronic transfusion and the importance of complying with chelation once it is started. There are no controlled clinical trials to guide the use of anticoagulants, antiplatelet agents, or thrombolytic agents in children, although these drugs are being used more and more often in pediatric patients. For the most part, our approach has been adapted from our experience with adults. Heparin followed by warfarin is often used for sinovenous thrombosis and for arterial dissection. I also suggest long-term anticoagulation for children with coagulopathy or a high risk of embolism due to congenital or acquired cardiac disease. It is reasonable to use a thrombolytic agent in children with an acute infarction; because few children present soon enough after the onset of symptoms, however, thrombolysis is infrequently used. Aspirin is used more than other antiplatelet agents in children, largely because of years of experience with aspirin and the lack of evidence that other agents are more effective. Despite its frequent use, there are no unequivocal indications for the use of aspirin in children. Aspirin is often started empirically in children suspected to be at substantial risk for additional ischemic stroke but whose risk is ill defined, an approach not too dissimilar from that often used in adult patients. Although the risk of Reye's syndrome in a child taking daily aspirin for stroke prevention is a common concern, I know of no published examples of children who developed Reye's syndrome while taking prophylactic aspirin. This apparently low risk must be weighed against the often-considerable risk of ischemic stroke that could be reduced by the use of daily aspirin. In situations such as vasculopathy or infarction of unknown cause, the small risk of Reye's syndrome seems acceptable.

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.

Neurologic outcome in survivors of childhood arterial ischemic stroke and sinovenous thrombosis

Ischemic stroke during infancy and childhood has the potential for life-long morbidity. Information on the neurologic outcome of children who survive ischemic stroke is lacking. Children surviving ischemic stroke between January 1, 1995 and July 1, 1999 were prospectively followed. Neurologic deficit severity was based on the Pediatric Stroke Outcome Measure (PSOM) developed in this study and parental response to two recovery questions. Predictor variables for poor outcome were tested. One-hundred twenty-three children with arterial ischemic stroke and 38 with sinovenous thrombosis were followed for a mean of 2.1 years (range, 0.8 to 6.6 years). The primary outcome based on PSOM assessment was: normal, 37%; mild deficit, 20%; moderate deficit, 26%; and severe deficit, 16%. The secondary outcome was full recovery in 45% of patients, based on parental response. The primary and secondary outcome measures were moderately correlated (P < .001; K = 0.5). In bivariate analysis, arterial stroke type, male gender, age of at least 28 days, presence of associated neurologic disorders, and need for rehabilitation therapy after stroke were predictors of poor outcome (P < .05). Multivariate analysis showed that only arterial ischemic stroke, associated neurologic disorders, and presence of rehabilitation therapy were independent predictors of poor outcome (P < .02). Poor outcome in children after ischemic stroke is therefore frequent and more likely in the presence of arterial stroke, rehabilitation therapy, and associated neurologic disorders, which justifies clinical trials of treatment strategies in childhood ischemic stroke.

Clinical manifestations of cerebrovascular hypoplasias in childhood

The aim of the study was to analyze cerebrovascular hypoplasia in childhood and its clinical manifestations in a clinical population of 205 children aged 3 to 14 years. Cerebrovascular hypoplasias were diagnosed using angiography (n=63), magnetic resonance angiography, and transcranial Doppler ultrasonography. Hypoplasias were localized in the internal carotid artery in 41.9% of patients, in the middle cerebral artery in 54.1%, the anterior cerebral artery in 1.0%, and in the vertebro-basilar system in 3.0%. Clinical manifestations included transient ischemic attacks (21% of patients), cerebral infarcts (17%), progressive unilateral cerebral hemisphere atrophy (1.0%), focal and secondary generalized epileptic seizures (56.1%), and migraine-like headache (4.9%). Hypoplasias of the internal carotid artery and middle cerebral artery manifested as focal and secondary generalized epileptic seizures, transient ischemic attacks, cerebral infarcts, migraine-like headache, and progressive unilateral cerebral hemisphere atrophy, in descending order of frequency. Hypoplasias in the anterior cerebral artery or the basilar artery caused cerebral infarcts, and hypoplasias in the vertebral arteries caused transient ischemic attacks. This article discusses the pathophysiology of ischemia in the territory of the hypoplastic cerebral artery in childhood, as well as possibilities for noninvasive neuroimaging for diagnosis of cerebrovascular hypoplasias.

Case report of fibromuscular dysplasia presenting as stroke in a 16-year-old boy

Fibromuscular dysplasia of the carotid artery is uncommon, but not rare. Although the true incidence and prevalence of the disease are not known, reported figures in adults range between 0.6% by angiography and 1.1% at autopsy. Most case reports of stroke caused by carotid fibromuscular dysplasia describe findings in adult subjects, although there are a few reports of the disease in children. In the present case, we describe a 16-year-old boy with fibromuscular dysplasia confined to one internal carotid artery and its branches, and in whom the disease declared itself by stroke. This case serves as a basis for considering diagnostic methods, treatment options, and future research in pediatric patients with cerebrovascular disease caused by fibromuscular dysplasia.

Stroke in children under 16 years of age. Clinical and etiological difference with adults

OBJECTIVES

The aim of this study was to re-evaluate the clinical features of stroke in children, their outcome and the place of the different mechanisms, in the light of CT-scan and magnetic resonance imaging.

METHODS

A 10-year review of the Dijon Childhood Neurology Clinic experience (1985-1995) identified 54 patients with arterial stroke. Diagnosis was established by CT-scan and angiography and by magnetic resonance imaging from 1987. When an hemorrhagic stroke was identified, a cerebral arteriogram and an investigation of the coagulation factors were performed. When an ischemic stroke was identified, the following tests were performed: an ultrasound examination of the cervical arteries, a cerebral arteriogram, a lumbar puncture, an investigation of the coagulation factors and lipid status, a measurement of homocystine in the plasma and the urine, an electrocardiogram, a Holter procedure and a cardiac echography.

RESULTS

During the 11 full calendar years of this study, we observed 54 stroke patients. There were 31 cases of ischemic stroke, representing some 57% of the total, as well as 23 cases of hemorrhagic stroke, representing 43% of the total. Of the 31 cases with ischemic stroke, 4 had no known predisposing condition, 6 occurred in children with pre-existing heart disease, 2 had moya-moya disease, 2 had leukemia, 2 had a carotid dissection, 1 had an hemolytic-uremic syndrome, and 14 were observed in patients with other associated conditions, such as infections (7 cases) or slight cranial trauma (7 cases). On CT-scan, a basal ganglia infarction was identified in 14 cases. Among the 23 hemorrhagic strokes, 9 were due to arteriovenous malformations, 2 to arterial aneurysm and 5 to cavernomas. Two cases occurred in hemophilia, 2 in idiopathic thrombocytopenic purpura, and 2 after throat infections. One case had no etiologic factor. Clinical course was marked by a low mortality rate even in hemorrhagic stroke, long-lasting seizures, and hemidystonia.

CONCLUSION

This neuro-imaging survey focused on the real place of hemorrhage and basal ganglia infarctions in children under 16 years of age, compared to adulthood. Follow-up demonstrated good or complete resolution of neurological deficits despite the frequent late hemidystonia and late epilepsy.