Left Temporal Pole Research Articles

Functional Decoding and Meta-analytic Connectivity Modeling in Adult Attention-Deficit/Hyperactivity Disorder

BackgroundTask-based functional magnetic resonance imaging (fMRI) studies of adult attention-deficit/hyperactivity disorder (ADHD) have revealed various ADHD-related dysfunctional brain regions, with heterogeneous findings across studies. Here, we used novel meta-analytic data-driven approaches to characterize the function and connectivity profile of ADHD-related dysfunctional regions consistently detected across studies. MethodsWe first conducted an activation likelihood estimation meta-analysis of 24 task-based fMRI studies in adults with ADHD. Each ADHD-related dysfunctional region resulting from the activation likelihood estimation meta-analysis was then analyzed using functional decoding based on ~7500 fMRI experiments in the BrainMap database. This approach allows mapping brain regions to functions not necessarily tested in individual studies, thus suggesting possible novel functions for those regions. Additionally, ADHD-related dysfunctional regions were clustered based on their functional coactivation profiles across all the experiments stored in BrainMap (meta-analytic connectivity modeling). ResultsADHD-related hypoactivation was found in the left putamen, left inferior frontal gyrus (pars opercularis), left temporal pole, and right caudate. Functional decoding mapped the left putamen to cognitive aspects of music perception/reproduction and the left temporal lobe to language semantics; both these regions clustered together on the basis of their meta-analytic functional connectivity. Left inferior gyrus mapped to executive function tasks; right caudate mapped to both executive function tasks and music-related processes. ConclusionsOur study provides meta-analytic support to the hypothesis that, in addition to well-known deficits in typical executive functions, impairment in processes related to music perception/reproduction and language semantics may be involved in the pathophysiology of adult ADHD.

Oxytocin receptor polymorphism and childhood social experiences shape adult personality, brain structure and neural correlates of mentalizing

IntroductionThe oxytocin system is involved in human social behavior and social cognition such as attachment, emotion recognition and mentalizing (i.e. the ability to represent mental states of oneself and others). It is shaped by social experiences in early life, especially by parent–infant interactions. The single nucleotid polymorphism rs53576 in the oxytocin receptor (OXTR) gene has been linked to social behavioral phenotypes. MethodIn 195 adult healthy subjects we investigated the interaction of OXTR rs53576 and childhood attachment security (CAS) on the personality traits “adult attachment style” and “alexithymia” (i.e. emotional self-awareness), on brain structure (voxel-based morphometry) and neural activation (fMRI) during an interactive mentalizing paradigm (prisoner's dilemma game; subgroup: n=163). ResultsWe found that in GG-homozygotes, but not in A-allele carriers, insecure childhood attachment is - in adulthood - associated with a) higher attachment-related anxiety and alexithymia, b) higher brain gray matter volume of left amygdala and lower volumes in right superior parietal lobule (SPL), left temporal pole (TP), and bilateral frontal regions, and c) higher mentalizing-related neural activity in bilateral TP and precunei, and right middle and superior frontal gyri. Interaction effects of genotype and CAS on brain volume and/or function were associated with individual differences in alexithymia and attachment-related anxiety. Interactive effects were in part sexually dimorphic. ConclusionThe interaction of OXTR genotype and CAS modulates adult personality as well as brain structure and function of areas implicated in salience processing and mentalizing. Rs53576 GG-homozygotes are partially more susceptible to childhood attachment experiences than A-allele carriers.

Sharing self-related information is associated with intrinsic functional connectivity of cortical midline brain regions.

Human beings are social animals and they vary in the degree to which they share information about themselves with others. Although brain networks involved in self-related cognition have been identified, especially via the use of resting-state experiments, the neural circuitry underlying individual differences in the sharing of self-related information is currently unknown. Therefore, we investigated the intrinsic functional organization of the brain with respect to participants’ degree of self-related information sharing using resting state functional magnetic resonance imaging and self-reported social media use. We conducted seed-based correlation analyses in cortical midline regions previously shown in meta-analyses to be involved in self-referential cognition: the medial prefrontal cortex (MPFC), central precuneus (CP), and caudal anterior cingulate cortex (CACC). We examined whether and how functional connectivity between these regions and the rest of the brain was associated with participants’ degree of self-related information sharing. Analyses revealed associations between the MPFC and right dorsolateral prefrontal cortex (DLPFC), as well as the CP with the right DLPFC, the left lateral orbitofrontal cortex and left anterior temporal pole. These findings extend our present knowledge of functional brain connectivity, specifically demonstrating how the brain’s intrinsic functional organization relates to individual differences in the sharing of self-related information.

Langerhans' cell histiocytosis of the temporal fossa: A case report.

Langerhans' cell histiocytosis (LCH) is a rare disease with a wide spectrum of clinical manifestations, varying from an isolated lesion to systemic involvement. The etiology of this disease remains to be elucidated. The present study reports a case of LCH with temporal fossa localization in an 8-year-old male patient, who had exhibited left temporal pain and headache for 1 month. Physical examination revealed slight exophthalmos and conjunctival hemorrhage in the patient's left eye, and non-contrast computed tomography imaging of the head revealed a soft tissue mass with unclear margins located in the left temporal fossa, as well as a wide bony defect. Magnetic resonance imaging revealed a heterogeneously contrast-enhanced mass near the left temporal pole, which eroded into the patient's left orbit and maxillary sinus. The lesion was totally excised and confirmed to be LCH through biopsy.

Somatotopic Semantic Priming and Prediction in the Motor System.

The recognition of action-related sounds and words activates motor regions, reflecting the semantic grounding of these symbols in action information; in addition, motor cortex exerts causal influences on sound perception and language comprehension. However, proponents of classic symbolic theories still dispute the role of modality-preferential systems such as the motor cortex in the semantic processing of meaningful stimuli. To clarify whether the motor system carries semantic processes, we investigated neurophysiological indexes of semantic relationships between action-related sounds and words. Event-related potentials revealed that action-related words produced significantly larger stimulus-evoked (Mismatch Negativity-like) and predictive brain responses (Readiness Potentials) when presented in body-part-incongruent sound contexts (e.g., “kiss” in footstep sound context; “kick” in whistle context) than in body-part-congruent contexts, a pattern reminiscent of neurophysiological correlates of semantic priming. Cortical generators of the semantic relatedness effect were localized in areas traditionally associated with semantic memory, including left inferior frontal cortex and temporal pole, and, crucially, in motor areas, where body-part congruency of action sound–word relationships was indexed by a somatotopic pattern of activation. As our results show neurophysiological manifestations of action-semantic priming in the motor cortex, they prove semantic processing in the motor system and thus in a modality-preferential system of the human brain.

The Brain Network of Naming: A Lesson from Primary Progressive Aphasia.

ObjectiveWord finding depends on the processing of semantic and lexical information, and it involves an intermediate level for mapping semantic-to-lexical information which also subserves lexical-to-semantic mapping during word comprehension. However, the brain regions implementing these components are still controversial and have not been clarified via a comprehensive lesion model encompassing the whole range of language-related cortices. Primary progressive aphasia (PPA), for which anomia is thought to be the most common sign, provides such a model, but the exploration of cortical areas impacting naming in its three main variants and the underlying processing mechanisms is still lacking.MethodsWe addressed this double issue, related to language structure and PPA, with thirty patients (11 semantic, 12 logopenic, 7 agrammatic variant) using a picture-naming task and voxel-based morphometry for anatomo-functional correlation. First, we analyzed correlations for each of the three variants to identify the regions impacting naming in PPA and to disentangle the core regions of word finding. We then combined the three variants and correlation analyses for naming (semantic-to-lexical mapping) and single-word comprehension (lexical-to-semantic mapping), predicting an overlap zone corresponding to a bidirectional lexical-semantic hub.Results and ConclusionsOur results showed that superior portions of the left temporal pole and left posterior temporal cortices impact semantic and lexical naming mechanisms in semantic and logopenic PPA, respectively. In agrammatic PPA naming deficits were rare, and did not correlate with any cortical region. Combined analyses revealed a cortical overlap zone in superior/middle mid-temporal cortices, distinct from the two former regions, impacting bidirectional binding of lexical and semantic information. Altogether, our findings indicate that lexical/semantic word processing depends on an anterior-posterior axis within lateral-temporal cortices, including an anatomically intermediate hub dedicated to lexical-semantic integration. Within this axis our data reveal the underpinnings of anomia in the PPA variants, which is of relevance for both diagnosis and future therapy strategies.

Decreased sleep duration is associated with increased fMRI responses to emotional faces in children

In adults and children, sleep loss is associated with affective dysregulation and increased responsivity to negative stimuli. Adult functional neuroimaging (fMRI) studies have demonstrated associations between restricted sleep and neural alterations in the amygdala and reward circuitry when viewing emotional picture and face stimuli. Despite this, few studies have examined the associations between short sleep duration and emotional responsivity in typically developing children, and no studies have investigated this relationship using fMRI. The current study examined the relationship between sleep duration and fMRI activation to emotional facial expressions in 15 male children (ages 7–11 years). During fMRI scanning, subjects viewed and made perceptual judgments regarding negative, neutral, and positive emotional faces. Maternal reported child sleep duration was negatively associated with (a) activation in the bilateral amygdala, left insula, and left temporal pole activation when viewing negative (i.e., fearful, disgust) vs. neutral faces, (b) right orbitofrontal and bilateral prefrontal activation when viewing disgust vs. neutral faces, and (c) bilateral orbitofrontal, right anterior cingulate, and left amygdala activation when viewing happy vs. neutral faces. Consistent with our prediction, we also noted that emotion-dependent functional connectivity between the bilateral amygdala and prefrontal cortex, cingulate, fusiform, and occipital cortex was positively associated with sleep duration. Paralleling similar studies in adults, these findings collectively suggest that decreased sleep duration in school-aged children may contribute to enhanced reactivity of brain regions involved in emotion and reward processing, as well as decreased emotion-dependent functional connectivity between the amygdala and brain regions associated with emotion regulation.

Neural response during anticipation of monetary loss is elevated in adult attention deficit hyperactivity disorder

Objectives: Risky behaviour seriously impacts the life of adult patients with attention deficit hyperactivity disorder (ADHD). Such behaviours have often been attributed to their exaggerated reward seeking, but dysfunctional anticipation of negative outcomes might also play a role. Methods: The present study compared adult patients with ADHD (n = 28) with matched healthy controls (n = 28) during anticipation of monetary losses versus gains while undergoing functional magnetic resonance imaging (fMRI) and skin conductance recording. Results: Skin conductance was higher during anticipation of losses compared to gains in both groups. Affective ratings of predictive cues did not differ between groups. ADHD patients showed increased activity in bilateral amygdalae, left anterior insula (region of interest analysis) and left temporal pole (whole brain analysis) compared to healthy controls during loss versus gain anticipation. In the ADHD group higher insula and temporal pole activations went along with more negative affective ratings. Conclusions: Neural correlates of loss anticipation are not blunted but rather increased in ADHD, possibly due to a life history of repeated failures and the respective environmental sanctions. Behavioural adaptations to such losses, however, might differentiate them from controls: future research should study whether negative affect might drive more risk seeking than risk avoidance.

A brain-lesion pattern based algorithm for the diagnosis of posttraumatic olfactory loss

Brain areas processing olfactory information exhibit functionally relevant morphological dynamics. This suggests the exploitation of anatomical information in the diagnosis of an olfactory dysfunction. Following previous identifications of olfactory eloquent areas such as the olfactory bulbs and tracts, we focused at a brain-morphology based algorithm for establishing the diagnosis of olfactory loss following brain injury. Forty-one patients with a history of head trauma dated back 40 ± 39 months, and additional 23 patients without head trauma, were assessed for damages in 11 olfaction-relevant brain areas using magnetic resonance imaging (MRI). Olfactory function was derived from the use of a standardized, reliable and validated olfactory test. An olfactory diagnostic algorithm was derived following classification and regression tree analysis of the brain lesion pattern. Subjects were assigned to olfactory diagnoses of anosmia, hyposmia or normosmia. These diagnoses were predictable at an accuracy of 62.3 % from the degree of damage in the olfactory bulb and in the left temporal lobe pole. The main diagnosis algorithm addressed the presence of anosmia, which could be predicted from the degree of damage in these brain areas at an accuracy of 81.3 %. We independently reproduced previously identified brain regions in which morphological damage is associated with olfactory loss. Based on this reproduction, an algorithm was developed for the diagnosis of anosmia from central-nervous damage. Thus, we introduce a morphological component to the olfactory diagnosis that specifically addresses clinical cases of olfactory loss following head trauma.

A brain-lesion pattern based algorithm for the diagnosis of posttraumatic olfactory loss.

Brain areas processing olfactory information exhibit functionally relevant morphological dynamics. This suggests the exploitation of anatomical information in the diagnosis of an olfactory dysfunction. Following previous identifications of olfactory eloquent areas such as the olfactory bulbs and tracts, we focused at a brain-morphology based algorithm for establishing the diagnosis of olfactory loss following brain injury. Forty-one patients with a history of head trauma dated back 40 ± 39 months, and additional 23 patients without head trauma, were assessed for damages in 11 olfaction-relevant brain areas using magnetic resonance imaging (MRI). Olfactory function was derived from the use of a standardized, reliable and validated olfactory test. An olfactory diagnostic algorithm was derived following classification and regression tree analysis of the brain lesion pattern. Subjects were assigned to olfactory diagnoses of anosmia, hyposmia or normosmia. These diagnoses were predictable at an accuracy of 62.3 % from the degree of damage in the olfactory bulb and in the left temporal lobe pole. The main diagnosis algorithm addressed the presence of anosmia, which could be predicted from the degree of damage in these brain areas at an accuracy of 81.3 %. We independently reproduced previously identified brain regions in which morphological damage is associated with olfactory loss. Based on this reproduction, an algorithm was developed for the diagnosis of anosmia from central-nervous damage. Thus, we introduce a morphological component to the olfactory diagnosis that specifically addresses clinical cases of olfactory loss following head trauma.

Cortical abnormalities and association with symptom dimensions across the depressive spectrum

BackgroundFew studies have investigated the relationship between structural brain abnormalities and dimensions of depressive symptomatology. MethodsIn the current study, we examined the relationship between cortical structural abnormalities and specific behavioral dimensions relevant to depression in a sample of unmedicated patients with major depressive disorder (MDD, n=57) and demographically similar healthy control volunteers (HC, n=29). All subjects underwent diagnostic assessment with the SCID, MRI at 3T, and dimensional assessments using the visual analog scales (VAS). Cortical regions were extracted for each subject, and group comparisons of cortical volume (CV), surface area (SA), and cortical thickness (CT) were performed controlling for multiple comparisons using a bootstrapping technique. Regions demonstrating group differences were analyzed for correlation with specific dimensions assessments. ResultsAs compared with HC, MDD subjects exhibited reduced CV within the left supramarginal gyrus, right ventrolateral prefrontal cortex (VLPFC), entorhinal cortex, parahippocampal gyrus, fusiform gyrus and pericalcarine; reduced SA in the right VLPFC, cuneus, and left temporal pole; and reduced CT in the right rostral anterior cingulate cortex (rACC) (all p's<0.05, corrected). The largest effect occurred within the right VLPFC for CV and SA (MDD<HC; effect sizes: 0.60). CV in the right VLPFC inversely correlated with sadness, fatigue and worry; CT in the right rACC inversely correlated with irritability and fatigue. LimitationsFuture studies will be required to further map the anatomical changes in depression to behavioral dimensions. ConclusionsOur results indicate that specific cortical abnormalities are associated with specific behavioral components linked to depression.

Familial temporal lobe epilepsy due to focal cortical dysplasia type IIIa

PurposeFocal cortical dysplasia (FCD) represents a common cause of refractory epilepsy. It is considered a sporadic disorder, but its occasional familial occurrence suggests the involvement of genetic mechanisms. MethodsSiblings with intractable epilepsy were referred for epilepsy surgery evaluation. Both patients were examined using video-EEG monitoring, MRI examination and PET imaging. They underwent left anteromedial temporal lobe resection. ResultsElectroclinical features pointed to left temporal lobe epilepsy and MRI examination revealed typical signs of left-sided hippocampal sclerosis and increased white matter signal intensity in the left temporal pole. PET examination confirmed interictal hypometabolism in the left temporal lobe. Histopathological examination of resected tissue demonstrated the presence FCD type IIIa, i.e. hippocampal sclerosis and focal cortical dysplasia in the left temporal pole. ConclusionWe present a unique case of refractory mesial temporal lobe epilepsy in siblings, characterized by an identical clinical profile and histopathology of FCD type IIIa, who were successfully treated by epilepsy surgery. The presence of such a high concordance between the clinical and morphological data, together with the occurrence of epilepsy and febrile seizures in three generations of the family pedigree points towards a possible genetic nature of the observed FCD type IIIa.

Familiarity for famous faces and names is not equally subtended by the right and left temporal poles. Evidence from an rTMS study

The aims of the present experiment was to investigate: (a) if transient disruption of neural activity in the right (RTP) or left temporal pole (LTP) can interfere with the development of a familiarity feeling to the presentation of faces/written names of famous/unknown people; and (b) if this interference specifically affects the familiarity for faces after inhibition of the RTP and for names after inhibition of the LTP. Twenty healthy volunteers took part in the study. Repetitive transcranial magnetic stimulation (rTMS) was administered online; it disrupted the neural activity of the right or left TP in concomitance with the presentation of each face and name whose familiarity had to be assessed. Furthermore, in a control group, each participant was submitted to a single experimental session in which rTMS was delivered to the vertex in association with the presentation of faces and written names.Since previous rTMS studies have shown that the temporary inactivation of the right and left TP influences the response latencies, but not the number of correct responses, in this study we took into account both the number of correct responses obtained in different experimental conditions and the corresponding response latencies.A three-way factorial ANOVA carried out on the Response Scores showed only a general effect of the Type of Stimuli, due to better performances on names than on faces. This greater familiarity of names is consistent with previous data reported in the literature. In the three-way factorial ANOVA carried out on the Latency Scores, post-hoc analyses showed an increased latency of responses to faces after right stimulation in Latency Total, Latency on Correct responses and Latency on Unfamiliar faces. None of these results were obtained in the control group. These data suggest that rTMS at the level of the RTP preferentially affects the development of familiarity feelings to the presentation of faces of famous people.

The Wernicke conundrum and the anatomy of language comprehension in primary progressive aphasia

Wernicke's aphasia is characterized by severe word and sentence comprehension impairments. The location of the underlying lesion site, known as Wernicke's area, remains controversial. Questions related to this controversy were addressed in 72 patients with primary progressive aphasia who collectively displayed a wide spectrum of cortical atrophy sites and language impairment patterns. Clinico-anatomical correlations were explored at the individual and group levels. These analyses showed that neuronal loss in temporoparietal areas, traditionally included within Wernicke's area, leave single word comprehension intact and cause inconsistent impairments of sentence comprehension. The most severe sentence comprehension impairments were associated with a heterogeneous set of cortical atrophy sites variably encompassing temporoparietal components of Wernicke's area, Broca's area, and dorsal premotor cortex. Severe comprehension impairments for single words, on the other hand, were invariably associated with peak atrophy sites in the left temporal pole and adjacent anterior temporal cortex, a pattern of atrophy that left sentence comprehension intact. These results show that the neural substrates of word and sentence comprehension are dissociable and that a circumscribed cortical area equally critical for word and sentence comprehension is unlikely to exist anywhere in the cerebral cortex. Reports of combined word and sentence comprehension impairments in Wernicke's aphasia come almost exclusively from patients with cerebrovascular accidents where brain damage extends into subcortical white matter. The syndrome of Wernicke's aphasia is thus likely to reflect damage not only to the cerebral cortex but also to underlying axonal pathways, leading to strategic cortico-cortical disconnections within the language network. The results of this investigation further reinforce the conclusion that the left anterior temporal lobe, a region ignored by classic aphasiology, needs to be inserted into the language network with a critical role in the multisynaptic hierarchy underlying word comprehension and object naming.

Characteristics of the whole-brain white-matter structural network in 2 to 3-year-old children with autism spectrum disorder

Objective To investigate the topological property alterations of the whole-brain white-matter (WM) structural network between 2 to 3-year-old children with autism spectrum disorder (ASD) children. Methods This research used diffusion tensor imaging(DTI) tractography to construct the human brain WM networks of 45 ASD children ranging from 2 to 3-year-old and 45 age- and sex-matched DD controls, followed by a graph theoretical analysis to establish topological architecture of the cerebral anatomical network, so as to further show the relationship between topological properties and clinical symptoms of the ASD group. Results The ASD children exhibited abnormal global topological properties, as indicated by decreased global efficiency(P=0.006), and increased characteristic path length (P=0.010). There were 11 hub nodes of the ASD group, 9 of them were the same as the DD controls, while the other two were right middle temporal gyrus and right dorsolateral superior frontal gyrus.Compared with DD controls, regional efficiency in several brain areas of ASD was significantly reduced(P<0.001), including left inferior frontal gyrus(orbital part), left superior frontal gyrus(medial orbital), right posterior cingulate gyrus, left inferior occipital gyrus, right precuneus, left paracentral lobule, bilateral caudate nucleus, left temporal pole and superior temporal gyrus(TPOsup). However, it also exhibited increased regional efficiency (P<0.001)in a few brain regions of ASD such as left supramarginal gyrus, right angular gyrus, and left heschl gyrus.Furthermore, no significant relationship was found between topological properties of the whole-brain WM structural network and clinical symptoms in ASD children. Conclusions The ASD toddlers exhibitedsmall-worldcharacter of the whole-brain WM structural network; the whole brain information transfer and interactions between brain regions are slower and less efficient than DD controls; the ASD group exhibited the phenomenon of coexistence of decreased and increased structural connectivity between different regions. Key words: Autism spectrum disorder; Diffusion tensor imaging; Brain network; Graph theoretical

Erythema ab igne

A 25-year-old woman was found dead in bed. She had a past history of seizures, alcohol and substance abuse, pancreatitis, psoriasis, pelvic inflammatory disease, hypertension, and depression. Previous admissions to hospital had been for chronic abdominal pain which was eased by holding a hot water bottle to her abdomen and back. At autopsy the major findings were limited to the brain which was swollen with flattening of gyri. There was no extradural or subdural hemorrhage. Subarachnoid hemorrhage was noted over the left temporal pole, with extension over the left frontal region and inferior surface of the left occipital lobe. This was associated with a ruptured saccular aneurysm of the left middle cerebral artery and adjacent intracerebral hemorrhage. The aneurysm was confirmed microscopically with reactive changes around the site of rupture at the apex of the lesion and at the margins of the intracerebral hematoma anteriorly suggesting that there had been an element of sentinel hemorrhage a few days prior to death. The pancreas had been completely effaced by firm, white, fibrous tissue containing calcific debris. At the tail of the pancreas, there was a 5 cm cyst with a smooth wall that contained white fluid with no evidence of infection. No other underlying organic diseases were present which could have caused or contributed to death. There was no evidence of a connective tissue disorder. There were no significant injuries and toxicology revealed therapeutic levels of quetiapine and temazepam, with tetrahydrocannabinol, but no alcohol or other common drugs. The other finding of note was the presence of areas of variegated pigmented skin with an arborescent pattern on the abdomen (Fig. 1) and to a lesser extent on the back. Microscopically the overlying epidermis was undulating with a basket-weave pattern of surface keratinization that ranged from a normal thickness to slight atrophy. The latter appeared due to a lichenoid reaction with foci of basal vacuolar change resulting in small numbers of apoptotic keratinocytes and papillary dermal colloid bodies. The papillary dermis showed a loose architecture from increased deposition of acid mucopolysaccharides. There was also a low grade lymphocytic inflammatory infiltrate with basal layer melanin pigmentation and moderate numbers of melanophages (Fig. 2). There was no epidermal basement membrane thickening or deep dermal inflammatory cell component, nor was there sweat gland necrosis, vasculitis, deep vaso-occlusive lesions, or pancreatic fat necrosis. There were no skin changes suggestive of psoriasis (which had been noted on the extensor surface of larger joints). Death was due to intracerebral and subarachnoid hemorrhage arising from a ruptured aneurysm of left middle cerebral artery. The striking skin lesions of a pigmented reticulate erythema on the abdominal wall were due to erythema ab igne caused by the recurrent application of a hot water bottle to the skin surface because of pain from chronic pancreatitis. & Roger W. Byard roger.byard@sa.gov.au

Relationship between structural brainstem and brain plasticity and lower-limb training in spinal cord injury: a longitudinal pilot study.

Rehabilitative training has shown to improve significantly motor outcomes and functional walking capacity in patients with incomplete spinal cord injury (iSCI). However, whether performance improvements during rehabilitation relate to brain plasticity or whether it is based on functional adaptation of movement strategies remain uncertain. This study assessed training improvement-induced structural brain plasticity in chronic iSCI patients using longitudinal MRI. We used tensor-based morphometry (TBM) to analyze longitudinal brain volume changes associated with intensive virtual reality (VR)-augmented lower limb training in nine traumatic iSCI patients. The MRI data was acquired before and after a 4-week training period (16–20 training sessions). Before training, voxel-based morphometry (VBM) and voxel-based cortical thickness (VBCT) assessed baseline morphometric differences in nine iSCI patients compared to 14 healthy controls. The intense VR-augmented training of limb control improved significantly balance, walking speed, ambulation, and muscle strength in patients. Retention of clinical improvements was confirmed by the 3–4 months follow-up. In patients relative to controls, VBM revealed reductions of white matter volume within the brainstem and cerebellum and VBCT showed cortical thinning in the primary motor cortex. Over time, TBM revealed significant improvement-induced volume increases in the left middle temporal and occipital gyrus, left temporal pole and fusiform gyrus, both hippocampi, cerebellum, corpus callosum, and brainstem in iSCI patients. This study demonstrates structural plasticity at the cortical and brainstem level as a consequence of VR-augmented training in iSCI patients. These structural changes may serve as neuroimaging biomarkers of VR-augmented lower limb neurorehabilitation in addition to performance measures to detect improvements in rehabilitative training.

Reduced paralimbic system gray matter volume in schizophrenia: Correlations with clinical variables, symptomatology and cognitive function

BackgroundPsychopathy is associated with dysfunction in regions that compose the paralimbic system, such as the orbitofrontal cortex (OFC), insular cortex (IC), temporal pole (TP), parahippocampal gyrus (PHG) and cingulate cortex (CC). However, findings of structural alterations in these regions are inconsistent in schizophrenia, and correlations between paralimbic system measures and symptomatology and cognitive function have not been investigated. Method93 patients with schizophrenia and 99 healthy controls received structural magnetic resonance imaging and clinical and cognitive assessment. We compared gray matter volume (GMV) between the two groups using voxel-based morphometry, and evaluated correlations between abnormal GMVs and clinical variables, symptomatology and cognitive function. The assessment of cognition included measures of processing speed, verbal fluency and memory. ResultsPatients with schizophrenia demonstrated significant GMV decreases in the paralimbic system, including bilateral OFC, IC and TP (p < 0.05, FWE corrected). GMV decreases were also observed in bilateral superior temporal gyri (STG). The GMVs in bilateral OFC, left IC, left TP and bilateral STG were positively correlated with processing speed, and the GMVs in bilateral OFC were positively correlated with memory function in all participants. In our patient group, the GMV deficits were also associated with earlier age of onset, longer duration of illness, greater number of hospitalizations and more severe positive symptoms. ConclusionsGMVs in the paralimbic system were significantly reduced in schizophrenia, and these abnormalities were correlated with clinical variables, symptomatology and cognitive function. These results suggest the paralimbic system plays an important role in the pathophysiology of schizophrenia.

Reduced default mode network connectivity in schizophrenia patients

In the present study, we explored possible alterations in the default mode network (DMN) and its functional connectivity in 41 schizophrenia patients and 42 age-matched healthy controls. Schizophrenia patients displayed reduced activation in the ventromedial prefrontal cortex, left superior temporal gyrus including auditory cortex and temporal pole. Psychophysiological interaction analysis revealed reduced connectivity between left superior temporal gyrus including auditory cortex and the left temporal pole in schizophrenia patients compared to healthy subjects.

Alterations in cortical thickness development in preterm-born individuals: Implications for high-order cognitive functions

Very preterm birth (gestational age <33weeks) is associated with alterations in cortical thickness and with neuropsychological/behavioural impairments. Here we studied cortical thickness in very preterm born individuals and controls in mid-adolescence (mean age 15years) and beginning of adulthood (mean age 20years), as well as longitudinal changes between the two time points. Using univariate approaches, we showed both increases and decreases in cortical thickness in very preterm born individuals compared to controls. Specifically (1) very preterm born adolescents displayed extensive areas of greater cortical thickness, especially in occipitotemporal and prefrontal cortices, differences which decreased substantially by early adulthood; (2) at both time points, very preterm-born participants showed smaller cortical thickness, especially in parahippocampal and insular regions. We then employed a multivariate approach (support vector machine) to study spatially discriminating features between the two groups, which achieved a mean accuracy of 86.5%. The spatially distributed regions in which cortical thickness best discriminated between the groups (top 5%) included temporal, occipitotemporal, parietal and prefrontal cortices. Within these spatially distributed regions (top 1%), longitudinal changes in cortical thickness in left temporal pole, right occipitotemporal gyrus and left superior parietal lobe were significantly associated with scores on language-based tests of executive function. These results describe alterations in cortical thickness development in preterm-born individuals in their second decade of life, with implications for high-order cognitive processing.