Electrical stimulation driving functional improvements and cortical changes in subjects with stroke

Experimental Brain Research - 2004-02-01Kimberley TJ, Lewis S, Auerbach EJ, Dorsey L, Lojovich JM, Carey JR10.1007/s00221-003-1695-y
It has been proposed that somatosensory stimulation in the form of electromyographically triggered neuromuscular electrical stimulation (NMES) to the peripheral nerve can influence functional measures of motor performance in subjects with stroke and can additionally produce changes in cortical excitability. Using a controlled, double-blind design, we studied the effects of intensive (60 h/3 weeks) treatment at home with NMES compared with a sham treatment, applied to the extensor muscles of the hemiplegic forearm to facilitate hand opening in 16 chronic stroke subjects. We investigated improvement in functional use of the hand and change in cortical activation as measured by
Functional Magnetic Resonance Imaging

Functional Magnetic Resonance Imaging (fMRI)

A functional neuroimaging procedure using MRI technology that measures brain activity by detecting changes associated with blood flow. This technique relies on the fact that cerebral blood flow and neuronal activation are coupled. When an area of the brain is in use, blood flow to that region also increases.[citation needed] The primary form of fMRI uses the blood-oxygen-level dependent (BOLD) contrast, discovered by Seiji Ogawa. This is a type of specialized brain and body scan used to map neural activity in the brain or spinal cord of humans or other animals by imaging the change in blood flow (hemodynamic response) related to energy use by brain cells. Since the early 1990s, fMRI has come to dominate brain mapping research because it does not require people to undergo shots, surgery, or to ingest substances, or be exposed to ionising radiation, etc.
. Following treatment, subjects improved on measures of grasp and release of objects (Box and Block Test and Jebsen Taylor Hand Function Test [JTHFT]: small objects, stacking, heavy cans), isometric finger extension strength, and self-rated Motor Activity Log (MAL): Amount of Use and How Well score. The sham subjects did not improve on any grasp and release measure or self-rated scale, but did improve on isometric finger extension strength. Importantly, however, following crossover, these subjects improved further in the measure of strength, grasp and release (Box and Block [JTHFT]: page turning), and self-rated MAL: Amount of Use score and How Well score. Using
fMRI

Functional Magnetic Resonance Imaging (fMRI)

A functional neuroimaging procedure using MRI technology that measures brain activity by detecting changes associated with blood flow. This technique relies on the fact that cerebral blood flow and neuronal activation are coupled. When an area of the brain is in use, blood flow to that region also increases.[citation needed] The primary form of fMRI uses the blood-oxygen-level dependent (BOLD) contrast, discovered by Seiji Ogawa. This is a type of specialized brain and body scan used to map neural activity in the brain or spinal cord of humans or other animals by imaging the change in blood flow (hemodynamic response) related to energy use by brain cells. Since the early 1990s, fMRI has come to dominate brain mapping research because it does not require people to undergo shots, surgery, or to ingest substances, or be exposed to ionising radiation, etc.
and a finger-tracking task, an index of cortical intensity in the ipsilateral somatosensory cortex increased significantly from pre-test to post-test following treatment. Cortical activation, as measured by voxel count, did not change. These findings suggest that NMES may have an important role in stimulating cortical sensory areas allowing for improved motor function.