Long-range fibre damage in small vessel brain disease affects aphasia severity
| Autor: | Alexandra Basilakos, Julius Fridriksson, Argye E. Hillis, Janina Wilmskoetter, Brielle C. Stark, Leonardo Bonilha, Chris Rorden, Gregory Hickok, Lisa Johnson, Barbara K. Marebwa |
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| Rok vydání: | 2019 |
| Předmět: |
Male
Aging Medical and Health Sciences Cerebral Ventricles 0302 clinical medicine Nerve Fibers Leukoencephalopathies Medicine magnetic resonance imaging 2.1 Biological and endogenous factors Aetiology Stroke Brain Diseases medicine.diagnostic_test 05 social sciences Leukoaraiosis Brain Middle Aged Magnetic Resonance Imaging White Matter stroke Brain disease medicine.anatomical_structure Cardiology Connectome Female medicine.symptom Adult medicine.medical_specialty 050105 experimental psychology White matter 03 medical and health sciences Internal medicine Aphasia Humans 0501 psychology and cognitive sciences brain connectomics Aged Neurology & Neurosurgery business.industry Psychology and Cognitive Sciences Neurosciences Magnetic resonance imaging Original Articles medicine.disease Hyperintensity Brain Disorders Neurology (clinical) Small vessel business 030217 neurology & neurosurgery |
| Zdroj: | Brain : a journal of neurology, vol 142, iss 10 Brain |
| Popis: | We sought to determine the underlying pathophysiology relating white matter hyperintensities to chronic aphasia severity. We hypothesized that: (i) white matter hyperintensities are associated with damage to fibres of any length, but to a higher percentage of long-range compared to mid- and short-range intracerebral white matter fibres; and (ii) the number of long-range fibres mediates the relationship between white matter hyperintensities and chronic post-stroke aphasia severity. We measured the severity of periventricular and deep white matter hyperintensities and calculated the number and percentages of short-, mid- and long-range white matter fibres in 48 individuals with chronic post-stroke aphasia. Correlation and mediation analyses were performed to assess the relationship between white matter hyperintensities, connectome fibre-length measures and aphasia severity as measured with the aphasia quotient of the Western Aphasia Battery-Revised (WAB-AQ). We found that more severe periventricular and deep white matter hyperintensities correlated with a lower proportion of long-range fibres (r = −0.423, P = 0.003 and r = −0.315, P = 0.029, respectively), counterbalanced by a higher proportion of short-range fibres (r = 0.427, P = 0.002 and r = 0.285, P = 0.050, respectively). More severe periventricular white matter hyperintensities also correlated with a lower proportion of mid-range fibres (r = −0.334, P = 0.020), while deep white matter hyperintensities did not correlate with mid-range fibres (r = −0.169, P = 0.250). Mediation analyses revealed: (i) a significant total effect of periventricular white matter hyperintensities on WAB-AQ (standardized beta = −0.348, P = 0.008); (ii) a non-significant direct effect of periventricular white matter hyperintensities on WAB-AQ (P > 0.05); (iii) significant indirect effects of more severe periventricular white matter hyperintensities on worse aphasia severity mediated in parallel by fewer long-range fibres (effect = −6.23, bootstrapping: standard error = 2.64, 95%CI: −11.82 to −1.56) and more short-range fibres (effect = 4.50, bootstrapping: standard error = 2.59, 95%CI: 0.16 to 10.29). We conclude that small vessel brain disease seems to affect chronic aphasia severity through a change of the proportions of long- and short-range fibres. This observation provides insight into the pathophysiology of small vessel brain disease, and its relationship with brain health and chronic aphasia severity. |
| Databáze: | OpenAIRE |
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