White matter microstructure predicts cognitive training-induced improvements in attention and executive functioning in schizophrenia

Abstract

We examined the relationship between white matter microstructure in schizophrenia using diffusion tensor imaging (DTI) and cognitive improvements induced by 70h (~16weeks) of cognitive training. We measured anatomical connectivity in 48 patients with schizophrenia (SZ) and 28 healthy control participants (HC) at baseline, and then examined the relationship between anatomical connectivity at baseline and training-induced cognitive gains in 30 SZ who performed diffusion imaging after completing 70h of training. Compared with healthy control participants, individuals with schizophrenia showed reduced white matter integrity at baseline, as indexed by fractional anisotropy metrics, in bilateral posterior corona radiata, bilateral retrolenticular internal capsules, bilateral posterior thalamic radiation, left anterior corona radiata, left superior longitudinal fasciculus, left sagittal stratum, right cerebral peduncle and the genu and splenium of the corpus callosum. After training, schizophrenia participants showed significant gains in attention/vigilance, speed of processing, verbal learning, visual learning and executive functioning. White matter integrity within the right fronto-occipital fasciculus predicted training-induced improvements in attention/vigilance, while white matter integrity within the right corticospinal tract and bilateral medial lemnisci predicted cognitive training-induced improvements in executive functioning, areas that did not show white matter tract deficits at baseline. These findings suggest that preserved white matter integrity connecting long-range prefrontal-thalamic-sensorimotor areas may be an important determinant for training-induced neurocognitive plasticity.

Cognitive deficits and white matter abnormalities in never-treated first-episode schizophrenia

“…WM fiber tracts are the neural architectures supporting high-speed interactions between different regions of the brain, and thus clinical and cognitive symptoms related to SCZ could be attributed to the alterations of WM pathways 38 . Previous studies have revealed the association between WM connections and cognitive performance in SCZ patients 39 – 43 . For example, executive and motor functioning deficits are linked to reduced WM integrity in the temporal and frontal connectivity in first-episode SCZ patients 32 .…”

A Study of the Characteristics of the White Matter in Schizophrenic Patients with Defective or Non-defective Symptoms by Diffuse Tensor Imaging

“…The radio-crown refers to the radial white matter bers from the inner capsule to the cerebral cortex, and the spatial arrangement of various projection bers with different functions is currently not completely clear [11] . Many studies have found varying degrees of damage to the right or bilateral radio-crown in patients with schizophrenia [12][13] . In this paper, the FA values in the right anterior radio-coronal region in patients with DS were lower compared with NDS patients, suggesting that the integrity of white matter bers in the radio-crown is more seriously damaged.…”

Multivariate pattern analysis of brain structure predicts functional outcome after auditory-based cognitive training interventions

“…We have previously shown at a group level, that the intact structure of thalamicprefrontal regions was also an important determinant of successful responsivity to cognitive training interventions in SCZ (14). Additionally, Ramsay et al showed that cognitive training was associated with increased thalamic-prefrontal activity and connectivity such that improved recruitment after cognitive training became correlated with overall improved cognitive functions (33).…”

“…Although these findings are promising at the group level, it is clear that there is a large amount of inter-individual variability in neural system and functional response to various forms of CT. Previous group-based studies have shown that baseline structural anatomical integrity (12)(13)(14) is associated with greater responsiveness to CT, suggesting that certain individual neurobiological characteristics might determine who will benefit the most from this intervention, but individual-level predictions have not yet been demonstrated. In particular, prior research indicates that patients with schizophrenia (SCZ) show most prominent deficits in auditory processing, that contributed to higher-level cognitive impairments and poor functioning (15)(16)(17) Promisingly, we have also found that the most prominent gains in auditory/verbal functions were induced after auditory-based CT (ABCT) interventions (18)(19)(20)(21)(22) This work prompted us to investigate multivariate pattern analyses (MVPA) to identify baseline patterns in grey matter (GM) volume in patients with schizophrenia (SCZ) that predicted improved functioning after an auditory-based CT (ABCT) intervention, operating at the single subject level.…”

“…Group-based studies have shown that increased GM volume has been predictive of improved functioning in SCZ patients and also associated with stronger resilience to functional deterioration (1,12). Informed by these prior group-based studies and meta-analyses (1,12,13), we hypothesized that patients who had increased GM volumes at baseline, particularly in prefrontal, thalamic and temporal regions (1,(12)(13)(14) would show improved functioning at the single subject level in response to 40 hours of ABCT. We further explored the relationship between the decision values of the functioning classifier generated in SCZ patients and their clinical characteristics at baseline and at follow-up to test whether clinical symptom severity or medication dose were associated with individual level of functioning after 40 hours of CT.…”