NeuroImage. Clinical
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NeuroImage. Clinical · Jan 2019
Severe asymptomatic carotid stenosis is associated with robust reductions in homotopic functional connectivity.
Severe (>70% narrowing) asymptomatic carotid stenosis (SACS) is associated with cognitive impairment and future strokes, and connectivity basis for the remote brain consequences is poorly understood. Here we explored homotopic connectivity and parenchymal lesions measured by multimodal magnetic resonance imaging (MRI) parameters in patients with SACS. Twenty-four patients with SACS (19 males/5 females; 64.25 ± 7.18 years), 24 comorbidities-matched controls (19 males/5 females; 67.16 ± 6.10 years), and an independent sample of elderly healthy controls (39 females/45 males; 57.92 ± 4.94 years) were included. ⋯ Further association analyses suggest that the decreased homotopic FC in these brain regions is most closely associated with delayed memory recall, sensorimotor processing, and other simple cognitive functions. Together, these results suggest that SACS predominately affects the lower-order brain systems, while higher-order systems, especially the topographies of default mode network, are least impacted initially, but may serve as a hallmark precursor to vascular dementia. Thus, assessment of homotopic FC may provide a means of noninvasively tracking the progression of downstream brain damage following asymptomatic carotid stenosis.
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NeuroImage. Clinical · Jan 2019
Widespread subcortical grey matter degeneration in primary lateral sclerosis: a multimodal imaging study with genetic profiling.
Primary lateral sclerosis (PLS) is a low incidence motor neuron disease which carries a markedly better prognosis than amyotrophic lateral sclerosis (ALS). Despite sporadic reports of extra-motor symptoms, PLS is widely regarded as a pure upper motor neuron disorder. The post mortem literature of PLS is strikingly sparse and very little is known of subcortical grey matter pathology in this condition. ⋯ PLS is associated with considerable subcortical grey matter degeneration and due to the extensive extra-motor involvement, it should no longer be regarded a pure upper motor neuron disorder. Given its unique pathological features and a clinical course which differs considerably from ALS, dedicated research studies and disease-specific therapeutic strategies are urgently required in PLS.
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NeuroImage. Clinical · Jan 2019
Meta AnalysisAlterations in grey matter density and functional connectivity in trigeminal neuropathic pain and trigeminal neuralgia: A systematic review and meta-analysis.
Various studies reported changes in grey matter volumes and modifications in functional connectivity of cortical and subcortical structures in patients suffering from trigeminal neuralgia (TN) and trigeminal neuropathic pain (TNP). This study meta-analyzed the concordant structural and functional changes in foci and provide further understanding of the anatomy and biology of TN/TNP. ⋯ Structural and functional changes meta-analyzed in this paper may contribute to elucidating the central pathophysiological mechanisms involved in TN/TNP. These results may be used as biomarkers to predict the response to medication and, ideally, in the future to offer personalized treatments.
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NeuroImage. Clinical · Jan 2019
Randomized Controlled TrialEffects of high- and low-frequency repetitive transcranial magnetic stimulation on motor recovery in early stroke patients: Evidence from a randomized controlled trial with clinical, neurophysiological and functional imaging assessments.
Repetitive transcranial magnetic stimulation (rTMS) can modulate cortical excitability, and may be beneficial for motor recovery after stroke. However, the neuroplasticity effects of rTMS have not been thoroughly investigated in the early stage after stroke. ⋯ HF- and LF-rTMS can both improve motor function by modulating motor cortical activation in the early phase of stroke.
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NeuroImage. Clinical · Jan 2019
Brainstem pathology in amyotrophic lateral sclerosis and primary lateral sclerosis: A longitudinal neuroimaging study.
Brainstem pathology is a hallmark feature of ALS, yet most imaging studies focus on cortical grey matter alterations and internal capsule white matter pathology. Brainstem imaging in ALS provides a unique opportunity to appraise descending motor tract degeneration and bulbar lower motor neuron involvement. ⋯ ALS and PLS patients exhibit considerable brainstem atrophy compared to both disease- and healthy controls. Volume reductions in ALS and PLS are dominated by medulla oblongata pathology, but pontine atrophy can also be detected. In ALS, vertex analyses confirm the flattening of the medullary pyramids bilaterally in comparison to healthy controls and widespread pontine shape deformations in contrast to PLS. The ALS cohort exhibit bilateral density reductions in the mesencephalic crura in contrast to healthy controls, central pontine atrophy compared to disease controls, peri-aqueduct mesencephalic and posterior pontine changes in comparison to PLS patients. CONCLUS: ions: Computational brainstem imaging captures the degeneration of both white and grey matter components in ALS. Our longitudinal data indicate progressive brainstem atrophy over time, underlining the biomarker potential of quantitative brainstem measures in ALS. At a time when a multitude of clinical trials are underway worldwide, there is an unprecedented need for accurate biomarkers to monitor disease progression and detect response to therapy. Brainstem imaging is a promising addition to candidate biomarkers of ALS and PLS.