•The thalamus has extensive functional connectivity to nine cortical resting state networks.•Thalamo-cortical connectivity strength decreases from childhood to early adulthood (5–25 ...y/o).•Thalamo-cortical connectivity strength is associated with cognitive abilities.
The thalamus has complex connections with the cortex and is involved in various cognitive processes. However, little is known about the age-related changes of thalamo-cortical connections and their relation to cognitive abilities. The present study analyzed resting-state functional connectivity between the thalamus and nine cortical functional networks (default mode network (DMN), posterior DMN, left/right executive, dorsal attention, salience, motor, visual and auditory network) in a healthy human sample (N = 95, aged 5–25 years). Cognitive abilities, including processing speed, selective attention, and cognitive flexibility were assessed using neuropsychological tests. All nine cortical resting-state networks showed functional connections to the thalamus at rest, with no effect for sex (p > 0.05). For the motor, visual, auditory, DMN, posterior DMN, salience and dorsal attention network, we found mainly bilateral thalamic projections in the mediodorsal nucleus, pulvinar and in nuclei of the lateral group. For the right and left lateralized executive network, corresponding lateralized thalamic projections were found. Thalamo-cortical connectivity strength showed significant age-related changes from distinct sub-nuclei of the thalamus to different cortical networks including the visual, DMN, salience and dorsal attention network. Further, connectivity strength of thalamo-cortical networks was associated with cognitive abilities, including processing speed, selective attention and cognitive flexibility. Better cognitive abilities were associated with increased thalamo-cortical connectivity in the pulvinar, mediodorsal nucleus, intralaminar nucleus, and nuclei from the lateral group. Alterations in the integrity of the thalamo-cortical system seem to be crucial for the development of cognitive abilities during brain maturation.
Over the last decade, increasing evidence of cognitive functions of the cerebellum during development and learning processes could be ascertained. Posterior fossa malformations such as cerebellar ...hypoplasia or Joubert syndrome are known to be related to developmental problems in a marked to moderate extent. More detailed analyses reveal special deficits in attention, processing speed, visuospatial functions and language. A study about Dandy Walker syndrome states a relationship of abnormalities in vermis lobulation with developmental problems. Further lobulation or volume abnormalities of the cerebellum and/or vermis can be detected in disorders as fragile X syndrome, Downs's syndrome or William's syndrome. Neuropsychological studies reveal a relation of dyslexia and attention deficit disorder with cerebellar functions. These functional studies are supported by structural abnormalities in neuroimaging in these disorders. Acquired cerebellar or vermis atrophy was found in groups of children with developmental problems such as prenatal alcohol exposure or extreme prematurity. Also focal lesions during childhood or adolescence such as cerebellar tumour or stroke are related with neuropsychological abnormalities, which are most pronounced in visuo-spatial, language and memory functions. In addition, cerebellar atrophy was shown to be a bad prognostic factor considering cognitive outcome in children after brain trauma and leukaemia. In ataxia teleangiectasia, a neurodegenerative disorder affecting primarily the cerebellar cortex, a reduced verbal IQ and problems of judgment of duration are a hint of the importance of the cerebellum in cognition. In conclusion, the cerebellum seems to play an important role in many higher cognitive functions especially in learning. There is a suggestion that the earlier the incorrect influence the more pronounced the problems.
Adaptive recovery of cerebral perfusion after pediatric arterial ischemic stroke (AIS) is sought to be crucial for sustainable rehabilitation of cognitive functions. We therefore examined cerebral ...blood flow (CBF) in the chronic stage after stroke and its association with cognitive outcome in patients after pediatric AIS. This cross-sectional study investigated CBF and cognitive functions in 14 patients (age 13.5 ± 4.4 years) after pediatric AIS in the middle cerebral artery (time since AIS was at least 2 years prior to assessment) when compared with 36 healthy controls (aged 13.8 ± 4.3 years). Cognitive functions were assessed with neuropsychological tests, CBF was measured with arterial spin labeled imaging in the anterior, middle, and posterior cerebral artery (ACA, MCA, PCA). Patients had significantly lower IQ scores and poorer cognitive functions compared to healthy controls (p < 0.026) but mean performance was within the normal range in all cognitive domains. Arterial spin labeled imaging revealed significantly lower CBF in the ipsilesional MCA and PCA in patients compared to healthy controls. Further, we found significantly higher interhemispheric perfusion imbalance in the MCA in patients compared to controls. Higher interhemispheric perfusion imbalance in the MCA was significantly associated with lower working memory performance. Our findings revealed that even years after a pediatric stroke in the MCA, reduced ipsilesional cerebral blood flow occurs in the MCA and PCA and that interhemispheric imbalance is associated with cognitive performance. Thus, our data suggest that cerebral hypoperfusion might underlie some of the variability observed in long-term outcome after pediatric stroke.
OBJECTIVETo test the hypothesis that the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is useful in determining outcomes after neonatal arterial ischemic stroke (NAIS), we assessed ...accuracy of the modified pediatric ASPECTS (pedASPECTS) to predict cerebral palsy (CP), neurologic impairment, and epilepsy.
METHODSCross-sectional study included newborns with acute NAIS whose outcomes were assessed at ≥18 months after stroke. PedASPECTS accuracy to predict outcomes was determined by sensitivity, specificity, and receiver operator characteristic (ROC) curves, and correlation between pedASPECTS and infarct volume was determined by the Spearman correlation coefficient.
RESULTSNinety-six children met the inclusion criteria. Median percentage infarct to supratentorial brain volume was 6.8% (interquartile range IQR 3.0%–14.3%). Median pedASPECTS was 7 (IQR 4–10). At a median age of 2.1 years, 35% developed CP, 43% had neurologic impairment, and 7% had epilepsy. Median pedASPECTS predicted outcomes of interestCP (10, IQR 8–12) vs no CP (5, IQR 4–8) (p < 0.0001), poor (9, IQR 7–12) vs good (6, IQR 4–8) neurologic outcomes (p < 0.0001), and epilepsy (10, IQR 8–12) vs no epilepsy (7, IQR 4–10) (p = 0.033). PedASPECTS accuracy was good for CP (ROC 0.811) and fair for neurologic impairment (ROC 0.760) and epilepsy (ROC 0.761). A pedASPECTS ≥8 had ≥69% sensitivity and ≥54% specificity for clinical outcomes. PedASPECTS correlated with infarct volume (Spearman rank 0.701, p < 0.0001).
CONCLUSIONSThis study provides Class II evidence that pedASPECTS has fair to good accuracy for predicting CP, neurologic impairment, and epilepsy after NAIS and correlates with infarct volume. PedASPECTS may assist with early identification of babies requiring close developmental surveillance.
OBJECTIVE:To compare long-term outcome of children and young adults with arterial ischemic stroke (AIS) from 2 large registries.
METHODS:Prospective cohort study comparing functional and psychosocial ...long-term outcome (≥2 years after AIS) in patients who had AIS during childhood (1 month–16 years) or young adulthood (16.1–45 years) between January 2000 and December 2008, who consented to follow-up. Data of children were collected prospectively in the Swiss Neuropediatric Stroke Registry, young adults in the Bernese stroke database.
RESULTS:Follow-up information was available in 95/116 children and 154/187 young adults. Median follow-up of survivors was 6.9 years (interquartile range 4.7–9.4) and did not differ between the groups (p = 0.122). Long-term functional outcome was similar (p = 0.896)53 (56%) children and 84 (55%) young adults had a favorable outcome (modified Rankin Scale 0–1). Mortality in children was 14% (13/95) and in young adults 7% (11/154) (p = 0.121) and recurrence rate did not differ (p = 0.759). Overall psychosocial impairment and quality of life did not differ, except for more behavioral problems among children (13% vs 5%, p = 0.040) and more frequent reports of an impact of AIS on everyday life among adults (27% vs 64%, p < 0.001). In a multivariate regression analysis, low Pediatric NIH Stroke Scale/NIH Stroke Scale score was the most important predictor of favorable outcome (p < 0.001).
CONCLUSION:There were no major differences in long-term outcome after AIS in children and young adults for mortality, disability, quality of life, psychological, or social variables.
Neonatal arterial ischemic stroke (NAIS) is associated with considerable lifetime burdens such as cerebral palsy, epilepsy, and cognitive impairment. Prospective epidemiologic studies that include ...outcome assessments are scarce. This study aimed to provide information on the epidemiology, clinical manifestations, infarct characteristics, associated clinical variables, treatment strategies, and outcomes of NAIS in a prospective, population-based cohort of Swiss children.
This prospective study evaluated the epidemiology, clinical manifestations, vascular territories, associated clinical variables, and treatment of all full-term neonates diagnosed with NAIS and born in Switzerland between 2000 and 2010. Follow-up was performed 2 years (mean 23.3 months, SD 4.3 months) after birth.
One hundred neonates (67 boys) had a diagnosis of NAIS. The NAIS incidence in Switzerland during this time was 13 (95% confidence interval CI, 11-17) per 100,000 live births. Seizures were the most common symptom (95%). Eighty-one percent had unilateral (80% left-sided) and 19% had bilateral lesions. Risk factors included maternal risk conditions (32%), birth complications (68%), and neonatal comorbidities (54%). Antithrombotic and antiplatelet therapy use was low (17%). No serious side effects were reported. Two years after birth, 39% were diagnosed with cerebral palsy and 31% had delayed mental performance.
NAIS in Switzerland shows a similar incidence as other population-based studies. About one-third of patients developed cerebral palsy or showed delayed mental performance 2 years after birth, and children with normal mental performance may still develop deficits later in life.
To develop individualized motor rehabilitation, knowledge of the relationship between neuroplastic reorganization and motor recovery after pediatric arterial ischemic stroke (AIS) is crucial. Thus, ...we investigated functional connectivity in patients after AIS with good motor outcome and in patients with hemiparesis compared with typically developing peers. We included 18 patients (n = 9 with hemiparesis, n = 9 with good motor outcome) with pediatric AIS in the chronic phase (≥ 2 years after diagnosis, diagnosed > 16 years) and 18 peers matched by age and gender. Participants underwent a standardized motor assessment, single-pulse transcranial magnetic stimulation to determine the type of corticospinal tract wiring, and resting-state functional magnetic resonance imaging to examine motor network connectivity. Corticospinal tract wiring was contralateral in all participants. Patients with hemiparesis had lower interhemispheric connectivity strength compared with patients with good clinical outcome and peers. Patients with good clinical outcome had higher intrahemispheric connectivity strength compared with peers. Further, higher intrahemispheric connectivity was related to better motor outcome in patients. Our findings suggest that better motor outcome after pediatric AIS is related to higher motor network connectivity strength. Thus, resting-state functional connectivity might be predictive for motor recovery after pediatric AIS.
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