Background Increasing somatosensory input can enhance functionally relevant brain reorganisation after stroke and is a potential mechanism of action of functional electrical stimulation (FES). The site of sensorimotor integration (SMI) is not yet clear, but may be different in controls and patients because of post-stroke brain reorganisation. Here we used fMRI to investigate SMI in the brain during FES. Methods Subjects were scanned during four conditions in a 2x2 factorial design: (1 & 2) repetitive unilateral active (moved by the subject) ankle dorsiflexion with and without concurrent electrical stimulation, (3 & 4) repetitive passive (moved by the experimenter) ankle dorsiflexion with and without concurrent electrical stimulation. Movements were performed with the affected ankle. FES was superficially applied to peroneal nerve; current was set subject by subject. Analysis was performed with SPM8. Here, we define SMI as the interaction between volitional movement and augmented proprioception. Results 10 chronic stroke patients and 16 age-matched healthy controls took part (range 28-72 yrs). In controls, all conditions elicited activity in S1 and M1. FES led to relative overactivity in SII. FES had an additional effect in M1 and S1 during active compared to passive movement. In patients, all conditions elicited activity in a more widely distributed network that included S1 and M1 (Fig. 1). In particular, FES had a greater effect during active compared to passive movement in ipsilesional postcentral and angular gyrus (Fig. 1). Conclusion In healthy subjects, SMI was seen in primary sensorimotor areas, whereas in patients it was seen in secondary areas (i.e. postcentral gyrus; angular gyrus). Angular gyrus is a recipient of proprioceptive information encoded in the postcentral gyrus. These results suggest that SMI takes place in a more widely distributed network of brain areas after stroke, and that patients may take advantage of secondary areas to support motor learning.
Functional anatomy of sensorimotor integration in chronic stroke patients
GANDOLLA, MARTA;FERRANTE, SIMONA;FERRIGNO, GIANCARLO;PEDROCCHI, ALESSANDRA LAURA GIULIA;
2013-01-01
Abstract
Background Increasing somatosensory input can enhance functionally relevant brain reorganisation after stroke and is a potential mechanism of action of functional electrical stimulation (FES). The site of sensorimotor integration (SMI) is not yet clear, but may be different in controls and patients because of post-stroke brain reorganisation. Here we used fMRI to investigate SMI in the brain during FES. Methods Subjects were scanned during four conditions in a 2x2 factorial design: (1 & 2) repetitive unilateral active (moved by the subject) ankle dorsiflexion with and without concurrent electrical stimulation, (3 & 4) repetitive passive (moved by the experimenter) ankle dorsiflexion with and without concurrent electrical stimulation. Movements were performed with the affected ankle. FES was superficially applied to peroneal nerve; current was set subject by subject. Analysis was performed with SPM8. Here, we define SMI as the interaction between volitional movement and augmented proprioception. Results 10 chronic stroke patients and 16 age-matched healthy controls took part (range 28-72 yrs). In controls, all conditions elicited activity in S1 and M1. FES led to relative overactivity in SII. FES had an additional effect in M1 and S1 during active compared to passive movement. In patients, all conditions elicited activity in a more widely distributed network that included S1 and M1 (Fig. 1). In particular, FES had a greater effect during active compared to passive movement in ipsilesional postcentral and angular gyrus (Fig. 1). Conclusion In healthy subjects, SMI was seen in primary sensorimotor areas, whereas in patients it was seen in secondary areas (i.e. postcentral gyrus; angular gyrus). Angular gyrus is a recipient of proprioceptive information encoded in the postcentral gyrus. These results suggest that SMI takes place in a more widely distributed network of brain areas after stroke, and that patients may take advantage of secondary areas to support motor learning.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
