Leftward asymmetry in relative fiber density of the arcuate fasciculus

Left hemispheric language dominance is well established, but the structural substrate for this functional asymmetry is uncertain. We report a strong asymmetry in the relative fiber density of the arcuate fasciculus, a white matter pathway associated with language that connects the frontal, temporal, and parietal lobes. Measured with diffusion tensor tractography, nearly all study participants demonstrated greater relative fiber density in the left arcuate fasciculus than in the right arcuate fasciculus. In comparison, we found no asymmetry in the corticospinal tract, an important white matter pathway with no known role in language. Combined with data on volumetric and activation asymmetry, greater connectivity may provide the elements of a neural system model for language lateralization.     

Extent of altered white matter in unilateral and bilateral periventricular white matter lesions in children with unilateral cerebral palsy

AimsTo investigate the extent of white matter damage in children with unilateral cerebral palsy (UCP) caused by periventricular white matter lesions comparing between unilateral and bilateral lesions; and to investigate a relationship between white matter microstructure and hand function.Methods and proceduresDiffusion MRI images from 46 children with UCP and 18 children with typical development (CTD) were included. Subjects were grouped by side of hemiparesis and unilateral or bilateral lesions. A voxel-wise white matter analysis was performed to identify regions where fractional anisotropy (FA) was significantly different between UCP groups and CTD; and where FA correlated with either dominant or impaired hand function (using Jebsen Taylor Hand Function Test).Outcomes and resultsChildren with unilateral lesions had reduced FA in the corticospinal tract of the affected hemisphere. Children with bilateral lesions had widespread reduced FA extending into all lobes. In children with left hemiparesis, impaired hand function correlated with FA in the contralateral corticospinal tract. Dominant hand function correlated with FA in the posterior thalamic radiations as well as multiple other regions in both left and right hemiparesis groups.Conclusions and implicationsPeriventricular white matter lesions consist of focal and diffuse components. Focal lesions may cause direct motor fibre insult resulting in motor impairment. Diffuse white matter injury is heterogeneous, and may contribute to more global dysfunction.What this paper adds

• ⿢Focal white matter alterations are observed in the corticospinal tract in UCP with unilateral white matter lesions
• ⿢Diffuse white matter alterations throughout all cerebral lobes are observed in UCP with bilateral white matter lesions
• ⿢Fractional anisotropy in the posterior thalamic radiations correlates with dominant hand function

     

Language outcomes subsequent to treatment of brainstem tumour in childhood

While the occurrence and management of brainstem tumours in children would not traditionally indicate potential direct structural impact on classical language centres, recent theories have implicated some involvement of the brainstem in a functional language and cognitive neural loop between the cerebellum and the cerebral hemispheres. Thus, the present paper explored the impact of treatment for brainstem tumour on the general and high-level language abilities of six children treated for brainstem tumour, in addition to phonological awareness skills. Group analysis revealed that children treated for brainstem tumour demonstrated intact language and phonological awareness abilities in comparison to an age- and gender-matched control group. Individual analysis revealed only one of six children treated for brainstem tumour revealed evidence of language disturbances, with an additional child demonstrating an isolated mildly reduced score on one phonological awareness task. Language deficits identified in a child treated with a combination of both radiotherapy and chemotherapy were noted in the high-level language area of lexical generation. Findings highlighted that no overt language disturbances were evident in children treated for brainstem tumour. However, further analysis into higher-level language skills in the present study indicated that both general and high-level language abilities require long-term monitoring in this population.     

Language exposure during infancy is negatively associated with white matter microstructure in the arcuate fasciculus

Decades of research have established that the home language environment, especially quality of caregiver speech, supports language acquisition during infancy. However, the neural mechanisms behind this phenomenon remain under studied. In the current study, we examined associations between the home language environment and structural coherence of white matter tracts in 52 typically developing infants from English speaking homes in a western society. Infants participated in at least one MRI brain scan when they were 3, 6, 12, and/or 24 months old. Home language recordings were collected when infants were 9 and/or 15 months old. General linear regression models indicated that infants who heard the most adult words and participated in the most conversational turns at 9 months of age also had the lowest fractional anisotropy in the left posterior parieto-temporal arcuate fasciculus at 24 months. Similarly, infants who vocalized the most at 9 months also had the lowest fractional anisotropy in the same tract at 6 months of age. This is one of the first studies to report significant associations between caregiver speech collected in the home and white matter structural coherence in the infant brain. The results are in line with prior work showing that protracted white matter development during infancy confers a cognitive advantage.     

Repeating through the insula: evidence from two consecutive strokes

Mixed transcortical aphasia is a very rare syndrome characterized by intact repetition, despite severe impairment in all other language modalities. In some cases, however, preservation of repetition is accompanied by intact reading. We report the case of a left-handed man who, after a subcortical stroke in the left hemisphere, showed the typical features of mixed transcortical aphasia with spared repetition and reading. After 10 days, a second stroke, involving the anterior insula and adjacent white matter bundles, markedly deteriorated repetition while his reading abilities recovered. By comparing features of repetition and reading before and after the second stroke, we provide evidence for the existence of a modular organization of language abilities, pointing to the primary role of the insula and surrounding white matter in phonological processing.     

Kallmann's syndrome: mirror movements associated with bilateral corticospinal tract hypertrophy

OBJECTIVE: To investigate the etiology of mirror movements in patients with X-linked Kallmann's syndrome (xKS) through statistical analysis of pooled white matter data from structural MR images. BACKGROUND: Mirror movements occur in 85% of xKS patients. Previous electrophysiologic studies have suggested an abnormal ipsilateral corticospinal tract projection in xKS patients exhibiting mirror movements. However, an alternative hypothesis has proposed a functional lack of transcallosal inhibitory fibers. METHODS: T1-weighted brain scans were normalized into stereotaxic space with segregation of gray and white matter to allow comparison of pooled white matter data on a voxel-by-voxel basis using SPM-96 software. Nine xKS patients were compared with two age-matched groups of nonmirroring individuals: nine patients with autosomal Kallmann's syndrome (aKS) and nine age-matched normal (healthy) men. RESULTS: Hypertrophy of the corpus callosum was found in both Kallmann's syndrome groups: the anterior and midsection in xKS, and the genu and posterior section in aKS. Bilateral hypertrophy of the corticospinal tract was found only in the group of xKS patients exhibiting mirror movements. SPM analysis was validated by an independent region of interest analysis of corpus callosum size. CONCLUSION: Although morphometry on its own cannot determine the cause of mirror movements, the specific finding of a hypertrophied corticospinal tract in xKS is consistent with electrophysiologic evidence suggesting that mirror movements in xKS result from abnormal development of the ipsilateral corticospinal tract fibers.     

Disentangling the relation between left temporoparietal white matter and reading: A spherical deconvolution tractography study

Diffusion tensor imaging (DTI) studies have shown that left temporoparietal white matter is related to phonological aspects of reading. However, DTI lacks the sensitivity to disentangle whether phonological processing is sustained by intrahemispheric connections, interhemispheric connections, or projection tracts. Spherical deconvolution (SD) is a nontensor model which enables a more accurate estimation of multiple fiber directions in crossing fiber regions. Hence, this study is the first to investigate whether the observed relation with reading aspects in left temporoparietal white matter is sustained by a particular pathway by applying a nontensor model. Second, measures of degree of diffusion anisotropy, which indirectly informs about white matter organization, were compared between DTI and SD tractography. In this study, 71 children (5–6 years old) participated. Intrahemispheric, interhemispheric, and projection pathways were delineated using DTI and SD tractography. Anisotropy indices were extracted, that is, fractional anisotropy (FA) in DTI and quantitative hindrance modulated orientational anisotropy (HMOA) in SD. DTI results show that diffusion anisotropy in both the intrahemispheric and projection tracts was positively correlated to phonological awareness; however, the effect was confounded by subjects’ motion. In SD, the relation was restricted to the left intrahemispheric connections. A model comparison suggested that FA was, relatively to HMOA, more confounded by fiber crossings; however, anisotropy indices were highly related. In sum, this study shows the potential of SD to quantify white matter microstructure in regions containing crossing fibers. More specifically, SD analyses show that phonological awareness is sustained by left intrahemispheric connections and not interhemispheric or projection tracts. Hum Brain Mapp 36:3273–3287, 2015. © 2015 Wiley Periodicals, Inc.     

Drawing connections between white matter and numerical and mathematical cognition: A literature review

In this review we examine white matter tracts that may support numerical and mathematical abilities and whether abnormalities in these pathways are associated with deficits in numerical and mathematical abilities. Diffusion tensor imaging (DTI) yields indices of white matter integrity and can provide information about the axonal organization of the brain. A growing body of research is using DTI to investigate how individual differences in brain microstructures relate to different numerical and mathematical abilities. Several tracts have been associated with numerical and mathematical abilities such as the superior longitudinal fasciculus, the posterior segment of the corpus callosum, inferior longitudinal fasciculus, corona radiata, and the corticospinal tract. Impairments in mathematics tend to be associated with atypical white matter structures within similar regions, especially in inferior parietal and temporal tracts. This systematic review summarizes and critically examines the current literature on white matter correlates of numerical and mathematical abilities, and provides directions for future research.     

Developmental differences in white matter architecture between boys and girls

Previous studies have found developmental differences between males and females in brain structure. During childhood and adolescence, relative white matter volume increases faster in boys than in girls. Sex differences in the development of white matter microstructure were investigated in a cohort of normal children ages 5-18 in a cross-sectional diffusion tensor imaging (DTI) study. Greater fractional anisotropy (FA) in boys was shown in associative white matter regions (including the frontal lobes), while greater FA in girls was shown in the splenium of the corpus callosum. Greater mean diffusivity (MD) in boys was shown in the corticospinal tract and in frontal white matter in the right hemisphere; greater MD in girls was shown in occipito-parietal regions and the most superior aspect of the corticospinal tract in the right hemisphere. Significant sex-age interactions on FA and MD were also shown. Girls displayed a greater rate of fiber density increase with age when compared with boys in associative regions (reflected in MD values). However, girls displayed a trend toward increased organization with age (reflected in FA values) only in the right hemisphere, while boys displayed this trend only in the left hemisphere. These results indicate differing developmental trajectories in white matter for boys and girls and the importance of taking sex into account in developmental DTI studies. The results also may have implications for the study of the relationship of brain architecture with intelligence.     

Reading impairment in a patient with missing arcuate fasciculus

We describe the case of a child (“S”) who was treated with radiation therapy at age 5 for a recurrent malignant brain tumor. Radiation successfully abolished the tumor but caused radiation-induced tissue necrosis, primarily affecting cerebral white matter. S was introduced to us at age 15 because of her profound dyslexia. We assessed cognitive abilities and performed diffusion tensor imaging (DTI) to measure cerebral white matter pathways. Diffuse white matter differences were evident in T1-weighted, T2-weighted, diffusion anisotropy, and mean diffusivity measures in S compared to a group of 28 normal female controls. In addition, we found specific white matter pathway deficits by comparing tensor-orientation directions in S's brain with those of the control brains. While her principal diffusion direction maps appeared consistent with those of controls over most of the brain, there were tensor-orientation abnormalities in the fiber tracts that form the superior longitudinal fasciculus (SLF) in both hemispheres. Tractography analysis indicated that the left and right arcuate fasciculus (AF), as well as other tracts within the SLF, were missing in S. Other major white matter tracts, such as the corticospinal and inferior occipitofrontal pathways, were intact. Functional MRI measurements indicated left-hemisphere dominanance for language with a normal activation pattern. Despite the left AF abnormality, S had preserved oral language with average sentence repetition skills. In addition to profound dyslexia, S exhibited visuospatial, calculation, and rapid naming deficits and was impaired in both auditory and spatial working memory. We propose that the reading and visuospatial deficits were due to the abnormal left and right SLF pathways, respectively. These results advance our understanding of the functional significance of the SLF and are the first to link radiation necrosis with selective damage to a specific set of fiber tracts.     

Magnetic resonance imaging correlates of first-episode psychosis in young adult male patients: combined analysis of grey and white matter

Background: Several patterns of grey and white matter changes have been separately described in young adults with first-episode psychosis. Concomitant investigation of grey and white matter densities in patients with first-episode psychosis without other psychiatric comorbidities that include all relevant imaging markers could provide clues to the neurodevelopmental hypothesis in schizophrenia. Methods: We recruited patients with first-episode psychosis diagnosed according to the DSM-IV-TR and matched controls. All participants underwent magnetic resonance imaging (MRI). Voxel-based morphometry (VBM) analysis and mean diffusivity voxel-based analysis (VBA) were used for grey matter data. Fractional anisotropy and axial, radial and mean diffusivity were analyzed using tract-based spatial statistics (TBSS) for white matter data. Results: We included 15 patients and 16 controls. The mean diffusivity VBA showed significantly greater mean diffusivity in the first-episode psychosis than in the control group in the lingual gyrus bilaterally, the occipital fusiform gyrus bilaterally, the right lateral occipital gyrus and the right inferior temporal gyrus. Moreover, the TBSS analysis revealed a lower fractional anisotropy in the first-episode psychosis than in the control group in the genu of the corpus callosum, minor forceps, corticospinal tract, right superior longitudinal fasciculus, left middle cerebellar peduncle, left inferior longitudinal fasciculus and the posterior part of the fronto-occipital fasciculus. This analysis also revealed greater radial diffusivity in the first-episode psychosis than in the control group in the right corticospinal tract, right superior longitudinal fasciculus and left middle cerebellar peduncle. Limitations: The modest sample size and the absence of women in our series could limit the impact of our results. Conclusion: Our results highlight the structural vulnerability of grey matter in posterior areas of the brain among young adult male patients with first-episode psychosis. Moreover, the concomitant greater radial diffusivity within several regions already revealed by the fractional anisotropy analysis supports the idea of a late myelination in patients with first-episode psychosis.     

Surgical treatment of paraventricular cavernous angioma: Fibre tracking for visualizing the corticospinal tract and determining surgical approach

Surgical treatment of deep-seated lesions involving the corticospinal tract is one of the most challenging areas of contemporary neurosurgery, even given the recent development of radiological methods including three-dimensional anisotropy contrast magnetic resonance imaging (MRI) axonography. Fibre tracking using diffusion tensor imaging is another MRI technique that can be used to visualize anisotropy and the orientation of white matter tracts in the brain. We report herein a patient with a paraventricular cavernous angioma manifesting as hemiparesis caused by haemorrhage. Preoperative conventional MRI failed to determine the anatomical relationship between the paraventricular lesion and the corticospinal tract, whereas fibre tracking using free software (dTV for MR-DTI analysis) indicated that the corticospinal tract was displaced anterolaterally from the medial side. The paraventricular lesion was completely removed without damaging the corticospinal tract using a transcortical transventricular approach. Preoperative fibre tracking is useful in surgical planning for procedures involving deep-seated lesions adjacent to the corticospinal tract, and may avoid postoperative morbidity due to corticospinal tract injury.     

Brain bases of morphological processing in young children

How does the developing brain support the transition from spoken language to print? Two spoken language abilities form the initial base of child literacy across languages: knowledge of language sounds (phonology) and knowledge of the smallest units that carry meaning (morphology). While phonology has received much attention from the field, the brain mechanisms that support morphological competence for learning to read remain largely unknown. In the present study, young English‐speaking children completed an auditory morphological awareness task behaviorally (n = 69, ages 6–12) and in fMRI (n = 16). The data revealed two findings: First, children with better morphological abilities showed greater activation in left temporoparietal regions previously thought to be important for supporting phonological reading skills, suggesting that this region supports multiple language abilities for successful reading acquisition. Second, children showed activation in left frontal regions previously found active in young Chinese readers, suggesting morphological processes for reading acquisition might be similar across languages. These findings offer new insights for developing a comprehensive model of how spoken language abilities support children's reading acquisition across languages. Hum Brain Mapp 36:2890–2900, 2015. © 2015 Wiley Periodicals, Inc.     

磁共振弥散张量成像在基底节区高血压脑出血致皮质脊髓束损伤中的应用研究

目的 探讨磁共振弥散张量成像(DTI)技术评价基底节区高血压脑出血(HICH)患者皮质脊髓束(CST)受损程度的意义及其与肌力恢复的关系.方法 徐州医学院附属医院神经外科自2006年11月至2009年5月行小骨窗开颅血肿清除术治疗单侧基底节区HICH患者35例,术后10 d应用3.0T磁共振DTI技术检测患者和10例健康志愿者CST,应用Functool软件进行图像分析观察CST损伤程度,HICH患者康复治疗2月后采用Brunnstrom标准进行肢体肌力检查,分析CST损伤程度与肢体肌力的相关性.结果 10例健康志愿者CST显示清晰.35例HICH患者CST受损的模式有3种:纤维束显示达正常侧的2/3或相仿(11例),患者肢体肌力恢复最好;纤维束显示小于正常侧的2/3(18例),患者肢体肌力恢复较好;纤维柬显示小于正常侧的1/3(6例),患者肢体肌力恢复最差.CST受损患者患侧的FA值均较健侧降低,差异有统计学意义(P<0.05).3种模式CST损伤患者患侧的FA值、肢体肌力不同,差异均有统计学意义(P=0.000).患者CST损伤程度与肌力恢复水平存在负相关关系(r=0.931,P=0.000).结论 应用磁共振DTI技术可显示脑内白质纤维束的走形及分布,能够早期检测HICH患者CST的损伤程度,对患者肢体运动功能损伤的评估、判断预后有重要的临床意义.     

Lateralization of the arcuate fasciculus from childhood to adulthood and its relation to cognitive abilities in children

The arcuate fasciculus is a major white matter tract involved in language processing that has also been repeatedly implicated in intelligence and reasoning tasks. Language in the human brain is lateralized in terms of both function and structure, and while the arcuate fasciculus reflects this asymmetry, its pattern of lateralization is poorly understood in children and adolescents. We used diffusion tensor imaging (DTI) and tractography to examine arcuate fasciculus lateralization in a large (n = 183) group of healthy right‐handed volunteers aged 5–30 years; a subset of 68 children aged 5–13 years also underwent cognitive assessments. Fractional anisotropy and number of streamlines of the arcuate fasciculus were both significantly higher in the left hemisphere than the right hemisphere in most subjects, although some subjects (10%) were right lateralized. Age and gender effects on lateralization were not significant. Children receiving cognitive assessments were divided into three groups: a “left‐only” group in whom only the left side of the arcuate fasciculus could be tracked, a left‐lateralized group, and a right‐lateralized group. Scores on the Peabody Picture Vocabulary Test (PPVT) and NEPSY Phonological Processing task differed significantly among groups, with left‐only subjects outperforming the right‐lateralized group on the PPVT, and the left‐lateralized children scoring significantly better than the right‐lateralized group on phonological processing. In summary, DTI tractography demonstrates leftward arcuate fasciculus lateralization in children, adolescents, and young adults, and reveals a relationship between structural white matter lateralization and specific cognitive abilities in children. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.     

Dynamic processing in the human language system: synergy between the arcuate fascicle and extreme capsule

The production and comprehension of human language is thought to involve a network of frontal, parietal, and temporal cortical loci interconnected by two dominant white matter pathways. These two white matter bundles, often referred to as the dorsal and ventral processing tracts, are hypothesized to have markedly different language functions. The dorsal tract is thought to process phonological processing, while the ventral tract is considered to abet semantics. This proposed functional differentiation of tracts is similar to the ventral and dorsal dichotomy proposed for the visual and auditory systems. The present study evaluated this characterization of the language system in the context of various components involved in its function. Twenty-four chronic stroke patients completed a battery of 10 language tests designed to measure performance on the comprehension and production of phonology, morphology, semantics, and syntax. The patients also completed diffusion MRI scanning. Lesions were confined to the left hemisphere, but the size and location of the insult varied so that patients had damage to a single tract, both tracts, or neither tract. Individual FA maps were generated, and focal areas of hypointensity served as markers of white matter damage. Whole-brain voxel-by-voxel correlations revealed that only phonological and semantic tasks fit into the dual-stream model, while syntax and morphology involved both pathways. ROI analyses of the arcuate fascicle and extreme capsule supported this finding. These data suggest that natural language function is more likely to reflect a synergistic system rather than a segregated dual-stream system.     

White matter development and early cognition in babies and toddlers

The normal myelination of neuronal axons is essential to neurodevelopment, allowing fast inter‐neuronal communication. The most dynamic period of myelination occurs in the first few years of life, in concert with a dramatic increase in cognitive abilities. How these processes relate, however, is still unclear. Here we aimed to use a data‐driven technique to parcellate developing white matter into regions with consistent white matter growth trajectories and investigate how these regions related to cognitive development. In a large sample of 183 children aged 3 months to 4 years, we calculated whole brain myelin volume fraction (VF_M) maps using quantitative multicomponent relaxometry. We used spatial independent component analysis (ICA) to blindly segment these quantitative VF_M images into anatomically meaningful parcels with distinct developmental trajectories. We further investigated the relationship of these trajectories with standardized cognitive scores in the same children. The resulting components represented a mix of unilateral and bilateral white matter regions (e.g., cortico‐spinal tract, genu and splenium of the corpus callosum, white matter underlying the inferior frontal gyrus) as well as structured noise (misregistration, image artifact). The trajectories of these regions were associated with individual differences in cognitive abilities. Specifically, components in white matter underlying frontal and temporal cortices showed significant relationships to expressive and receptive language abilities. Many of these relationships had a significant interaction with age, with VF_M becoming more strongly associated with language skills with age. These data provide evidence for a changing coupling between developing myelin and cognitive development. Hum Brain Mapp 35:4475–4487, 2014. © 2014 The Authors. Human Brain Mapping Published by Wiley Periodicals, Inc.     

Reorganization of the corticospinal tract following neonatal unilateral cortical ablation in rats

The corticospinal tract in the rat after neonatal ablation of the unilateral cerebral cortex was studied morphologically and histochemically using the retrograde and antegrade horseradish peroxidase (HRP) tracing methods. The normal corticospinal tract in the lumbar cord was composed of a number of small and some large axons. In the atrophic corticospinal tract related to the ablated cerebral cortex, the small axons were decreased in number two weeks after the operation. However, new myelinated small axons appeared around day 28 and their diameters increased gradually from after day 56 to day 84. The original large axon in the atrophic corticospinal tract was much more increased in size than that in the corticospinal tract of the non-operated-on control. When HRP was injected into the left cervical cord of the adult rat whose right cerebral cortex had been ablated during the neonatal period, a considerable number of HRP-labeled neurons was seen in the healthy left cerebral cortex. When the corticospinal tract was traced antegradely by injecting HRP into the healthy left cerebral cortex, an aberrant corticospinal tract reaching into the ipsilateral dorsal funiculus was observed. These results give a morphological basis for the well known fact that children who have had brain damage during the neonatal period and early infancy have the capacity for recovery of motor function.     

Diffusion tensor imaging and tractography of central pontine myelinolysis

OBJECTIVES: To illustrate the value of diffusion tensor imaging and tractography in the diagnosis and follow-up of central pontine myelinolysis. CASE REPORT: We report a case of central pontine myelinolysis in a 29 year old woman, also anorexic, studied using MR Diffusion Tensor Imaging (DTI) and Fibre Tracking (FT) focused on the pons, and compared with the studies of 5 normal volunteers. Tractography showed a swollen aspect of the right corticospinal fiber tract correlating with mild left lower extremity deficit at clinical evaluation. The pontine fibers were posteriorly displaced but intact. The sensory tracts were also intact. Apparent Diffusion Coefficient values were increased and Fractional Anisotropy was decreased in the lesions. Follow up imaging showed persistent abnormal ADC and FA values in the pons although the left cortico-spinal tract returned to normal, consistent with the clinical outcome. CONCLUSION: Diffusion Tensor Imaging MR and Fiber tractography are a new method to analyse white matter tracts. It can be used to prospectively evaluate the location of white matter tract lesions at the acute phase of central pontine myelinolysis and follow up.     

Alterations of structural and functional connectivity in profound sensorineural hearing loss infants within an early sensitive period: A combined DTI and fMRI study

Due to heightened level of neuroplasticity, there is a sensitive period (2–4 years after birth) that exists for optimal central auditory development. Using diffusion tensor imaging combined with resting-state functional connectivity (rsFC) analysis, this study directly investigates the structural connectivity alterations of the whole brain white matter (WM) and the functional reorganization of the auditory network in infants with sensorineural hearing loss (SNHL) during the early sensitive period. 46 bilateral profound SNHL infants prior to cochlear implantation (mean age, 17.59 months) and 33 healthy controls (mean age, 18.55 months) were included in the analysis. Compared with controls, SNHL infants showed widespread WM alterations, including bilateral superior longitudinal fasciculus, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, right corticospinal tract, posterior thalamic radiation and left uncinate fasciculus. Moreover, SNHL infants demonstrated increased rsFC between left/right primary auditory cortex seeds and right insula and superior temporal gyrus. In conclusion, this study suggests that SNHL in the early sensitive period is associated with diffuse WM alterations that mainly affect the auditory and language pathways. Furthermore, increased rsFC in areas mainly associated with auditory and language networks may potentially reflect reorganization and compensatory activation in response to auditory deprivation during the early sensitive period.