Article

Nearly 15 million people suffer from stroke every year worldwide,
with about 20% of the survivors retaining chronic aphasic symptoms. Spontaneous
recovery is limited to 3 to 6 months. Cortical stimulation techniques have been
proposed to enhance the recovery process. OBJECTIVE: The goal of this study was
to evaluate the benefit of epidural cortical stimulation for the treatment of
poststroke aphasia, based on a systematic review of the literature. METHODS: An
extensive PubMed search was performed for English language articles published
from 1990 to 2014 with the keywords (cortical OR epidural) AND stimulation AND
stroke AND (aphasia OR language OR speech). The criteria analyzed included the
type of study, epidemiology of patients, stroke, aphasia, stimulation protocol,
concurrent rehabilitation therapies, language evaluations, results observed, and
follow-up. RESULTS: Seven cases were reported to date
(3 case reports, 1
randomized controlled trial). All patients experienced nonfluent aphasia
following an ischemic stroke.
All four studies reported encouraging effects of
the stimulation with improved lexical access and fluency for all patients. The
effects were specific, independent of the motor recovery or of the pain reported
by the patients, and they were linked to the stimulation parameters. CONCLUSIONS:
Due to the small number of existing cases in the literature, the strength of the
evidence is still low. Two main hypotheses of neurobiological mechanisms have
been explored: either using continuous stimulation to modify cortical
perilesional inhibition or using intermittent stimulation during the speech and
language therapy sessions to explore synaptic plasticity and long-term
potentiation or depression.
To establish the role of epidural stimulation and the
relevant stimulation protocols and parameters, large randomized controlled trials
are mandatory. We suggest avenues of investigation.
CI - (c) The Author(s) 2015.

Langue : ANGLAIS