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Abstract Body

BACKGROUND AND AIMS

The brain’s functional organization is dynamic and reconfigures across time implying the capability of brain regions to propagate neural activity (ignition events) and to switch between brain states (metastability). This ensures brain functioning. We aim to investigate how extreme prematurity disturbs the functional organization of the brain by adopting an intrinsic ignition and metastability framework using resting state MRI.

METHODS

Sample: 33 extremely preterm (EPT) children (23.5–26.6 weeks of gestation) and 28 term controls (37.3–41.5 weeks of gestation) scanned at 10 years of age and assessed with WISC-V at 12 years. Intrinsic-ignition and metastability were calculated in seven networks (default-DMN, limbic, motor, visual, dorsal attention-DAN, salience and fronto-parietal). Differences were tested between EPT and term using Monte-Carlo permutations corrected for multiple comparisons. Spearman’s correlation between brain data and developmental scores were performed.

RESULTS

Compared to the term group, EPT children showed reduced mean ignition and metastability in the DMN (p= 0.002 and p=0.00001 respectively) and DAN (p= 0.011 and p=0.00001 respectively). Metastability was also reduced in the salience network (p=0.02). Significant correlations between brain data and developmental scores were found only in the term group. Metastability in the DAN was positively correlated with processing speed (r_s=0.53, p=0.02), visuospatial (r_s=0.50, p=0.02) , and IQ (r_s 0.56, p=0.008).

CONCLUSIONS

EPT birth disturbs the signatures of functional brain organization at rest involving mainly higher-order networks. This may have a key role in related cognitive impairments described in this population.

Abstract Body

Background and aims

Language is a complex system and magnetic resonance imaging (MRI) has made it possible to further understand which parts of the brain are important for language processing (1,2). There are studies indicating that brain volumes correlate with language outcome (3,4). We aimed to investigate language-related brain volumes of extremely preterm children (EPT) vs full-term controls and see if they correlate with language outcome.

Methods

We included 50 EPT children and 37 controls, scanned with MRI at 10y and developmentally assessed at 12y. Atlas based segmentation identified language-related areas: the frontal gyrus, superior, middle and inferior temporal gyrus, angular and supramarginal region, supplementary motor areas, Heschl’s gyrus (1,2). The volumes were analyzed separately and added together as a network. Pearson’s correlations were performed between brain data and WISC V language-related scores as well as Clinical evaluation of language fundamentals (CELF-4) - repetition of sentences. Covariates were used as appropriate.

Results

All examined regions were significantly smaller for the EPT group vs the full-term controls, except for Heschl’s gyrus when controlled for sex, handedness, age at scan and intracranial volume. In the EPT group the volume of the language network significantly correlated positively with vocabulary within the WISC V (r=0.33) test and repetition of sentences score within the CELF 4 test (r=0.39).

Conclusions:

These findings demonstrate abnormal development of language-related brain regions in EPT children with an impact on their functional outcome.

(1) Sakai 2005

(2) Friedrichi 2011

(3) Monson 2016

(4) Stipdonk 2018