Changes in Resting-State Connectivity following Melody-Based Therapy in a Patient with Aphasia

Abstract

Melody-based treatments for patients with aphasia rely on the notion of preserved musical abilities in the RH, following left hemisphere damage. However, despite evidence for their effectiveness, the role of the RH is still an open question. We measured changes in resting-state functional connectivity following melody-based intervention, to identify lateralization of treatment-related changes. A patient with aphasia due to left frontal and temporal hemorrhages following traumatic brain injuries (TBI) more than three years earlier received 48 sessions of melody-based intervention. Behavioral measures improved and were maintained at the 8-week posttreatment follow-up. Resting-state fMRI data collected before and after treatment showed an increase in connectivity between motor speech control areas (bilateral supplementary motor areas and insulae) and RH language areas (inferior frontal gyrus pars triangularis and pars opercularis). This change, which was specific for the RH, was greater than changes in a baseline interval measured before treatment. No changes in RH connectivity were found in a matched control TBI patient scanned at the same intervals. These results are compatible with a compensatory role for RH language areas following melody-based intervention. They further suggest that this therapy intervenes at the level of the interface between language areas and speech motor control areas necessary for language production.

Simultaneous Normalization and Compensatory Changes in Right Hemisphere Connectivity during Aphasia Therapy

“…This hypothesis is supported by findings from brain stimulation studies, wherein the suppression of specific regions in the right hemisphere in non-fluent aphasia resulted in improved language performances [15][16][17][18]. In contrast, other studies suggest that the increased involvement of the right hemisphere (RH) in language processing following left hemisphere damage reflects compensatory supportive processes [8,[19][20][21][22][23][24][25]. Recent work by Kiran et al [26] suggests that although spared tissue within the left hemisphere is critically engaged in language recovery, right hemisphere regions are also involved in this process.…”

“…It is widely accepted that analysis of brain connectivity is of significant importance to the understanding of brain plasticity [3,43,44]. Changes in functional connectivity among PWA have been reported in several studies [45][46][47][48], and specific changes in the language network have been detected following language therapy [21,49,50]. Effective connectivity, which refers to the causal influence that neural populations exert on each other and can be inferred from fMRI data, has been analyzed in several language studies in healthy individuals [42,[51][52][53][54][55][56][57].…”

Music Therapy in Global Aphasia: A Case Report

“…In aphasia, melody-based treatments rely on the notion that they can induce structural white matter neuroplasticity and that right hemisphere (with preserved musical abilities) can have compensatory role. Bitan et al [ 11 ] show how the use of melody-based treatment results in increased connectivity between motor speech control areas (bilateral supplementary motor areas and insulae) and right hemisphere language areas (inferior frontal gyrus pars triangularis and pars opercularis). Sihvonen et al [ 12 ] found that a 3-month neurological music therapy treatment resulted in increased quantitative anisotropy (QA) in the right dorsal pathways (arcuate fasciculus and superior longitudinal fasciculus) and in the corpus callosum and the right frontal aslant tract, thalamic radiation and corticostriatal tracts.…”

Adaptation of Melodic Intonation Therapy to a Tone Language: A Pilot Study of Tone-Rhythmic Therapy in Mandarin Chinese

“…Recent fMRI investigations have also shown that the right hemisphere plays a key role in MIT treatment. For example, Bitan et al [18] analyzed resting-state fMRI data gathered before and after MIT therapy and found that the connection between bilateral motor speech control areas and right-hemispheric “language center” (inferior frontal gyrus, pars triangularis, and pars opercularis) had improved.…”