Article

Research on the neural substrate of aphasia recovery has consistently increased
since the advent of functional neuroimaging. The evidence from therapy-induced
aphasia recovery studies shows that better recovery results from the reactivation
of left hemisphere function; still, the specific left hemisphere key areas that
sign successful outcome with a specific therapy approach remain to be identified.
Nine participants suffering from aphasia received brief and intensive therapy
with Semantic Feature Analysis (SFA). Behavioural and neuroimaging data during
overt picture naming were obtained prior to and after therapy. This paper reports
on a group of participants having benefited from SFA, and two distinct patterns
of improvement. Correlational analysis showed that differences in outcome were
not related to lesion size, but were negatively correlated with damage to Broca's
area (BA45). Moreover, a group analysis showed that therapy-induced recovery
following SFA was characterized by (a) a significant correlation between
improvement and activation in the left precentral gyrus (BA4/6) before therapy,
and (b) the recruitment of the left inferior parietal lobule, an area known for
its role in semantic integration, following therapy with SFA. Individual fMRI
analyses showed that although adaptive brain plasticity appeared to operate
differently in each patient, best responders to SFA therapy recruited less areas
after training compared to participants having shown less recovery who showed a
larger number of activated areas sustaining recovery. The results of the present
study suggest that a significant activation of BA4/6 could indicate the use of
SFA to achieve successful outcome. Also our results suggest that greater SFA
improvement in chronic aphasia is associated with recruitment of areas in the
left hemisphere.
CI - Copyright (c) 2012 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS