Article

The brain may reorganize to optimize stroke recovery. Yet relatively
little is known about neural correlates of training-facilitated recovery,
particularly after loss of body sensations.
OBJECTIVE: Our aim was to
characterize changes in brain activation following clinically effective touch
discrimination training in stroke patients with somatosensory loss after lesions
of primary/secondary somatosensory cortices or thalamic/capsular somatosensory
regions using functional magnetic resonance imaging (fMRI). METHODS: Eleven
stroke patients with somatosensory loss, 7 with lesions involving primary (S1)
and/or secondary (S2) somatosensory cortex (4 male, 58.7 +/- 13.3 years) and 4
with lesions primarily involving somatosensory thalamus and/or capsular/white
matter regions (2 male, 58 +/- 8.6 years) were studied. Clinical and MRI testing
occurred at 6 months poststroke (preintervention), and following 15 sessions of
clinically effective touch discrimination training (postintervention). RESULTS:
Improved touch discrimination of a magnitude similar to previous clinical studies
and approaching normal range was found. Patients with thalamic/capsular
somatosensory lesions activated preintervention in left ipsilesional
supramarginal gyrus, and postintervention in ipsilesional insula and
supramarginal gyrus. In contrast, those with S1/S2 lesions did not show common
activation preintervention, only deactivation in contralesional superior parietal
lobe, including S1, and cingulate cortex postintervention. The S1/S2 group did,
however, show significant change over time involving ipsilesional precuneus. This
change was greater than for the thalamic/capsular group (P = .012; d = -2.43; CI
= -0.67 to -3.76). CONCLUSION: Different patterns of change in activation are
evident following touch discrimination training with thalamic/capsular lesions
compared with S1/S2 cortical somatosensory lesions, despite common training and
similar improvement.
CI - (c) The Author(s) 2016.

Langue : ANGLAIS