Abnormal muscle activation patterns are associated with chronic gait deficits following traumatic brain injury.

Background: Gait and balance disorders are common among individuals who have experienced a mild to moderate traumatic brain injury (TBI). However, little is known about how the neuromuscular control of gait is altered following a TBI.

Research Question: Investigate the relationship between lower limb muscle activation patterns and chronic gait deficits in individuals who previously experienced a mild to moderate TBI.

Non-invasive neuromodulation to improve gait in chronic multiple sclerosis: a randomized double blind controlled pilot trial.

Background: This study sought to examine the effect of targeted physical therapy with and without cranial nerve non-invasive neuromodulation (CN-NINM), on the walking ability of people with MS who exhibited a dysfunctional gait. We hypothesized that subjects who received electrical stimulation would have greater improvement than those who had a control device after a 14-week intervention. Gait disturbance is a common problem for people with multiple sclerosis (MS).

Altered connectivity of the balance processing network after tongue stimulation in balance-impaired individuals.

Some individuals with balance impairment have hypersensitivity of the motion-sensitive visual cortices (hMT+) compared to healthy controls. Previous work showed that electrical tongue stimulation can reduce the exaggerated postural sway induced by optic flow in this subject population and decrease the hypersensitive response of hMT+. Additionally, a region within the brainstem (BS), likely containing the vestibular and trigeminal nuclei, showed increased optic flow-induced activity after tongue stimulation.

High-resolution fMRI detects neuromodulation of individual brainstem nuclei by electrical tongue stimulation in balance-impaired individuals.

High-resolution functional magnetic resonance imaging (fMRI) can be used to precisely identify blood oxygen level dependent (BOLD) activation of small structures within the brainstem not accessible with standard fMRI. A previous study identified a region within the pons exhibiting sustained neuromodulation due to electrical tongue stimulation, but was unable to precisely identify the neuronal structure involved. For this study, high-resolution images of neural activity induced by optic flow were acquired in nine healthy controls and nine individuals with balance dysfunction before and after information-free tongue stimulation.

Electrical tongue stimulation normalizes activity within the motion-sensitive brain network in balance-impaired subjects as revealed by group independent component analysis.

Multivariate analysis of functional magnetic resonance imaging (fMRI) data allows investigations into network behavior beyond simple activations of individual regions. We apply group independent component analysis to fMRI data collected in a previous study looking at the sustained neuromodulatory effects of electrical tongue stimulation in balance-impaired individuals. Twelve subjects with balance disorders viewed optic flow in an fMRI scanner before and after 5 days of electrical tongue stimulation.

Sustained cortical and subcortical neuromodulation induced by electrical tongue stimulation.

This pilot study aimed to show that information-free stimulation of the tongue can improve behavioral measures and induce sustained neuromodulation of the balance-processing network in individuals with balance dysfunction. Twelve balance-impaired subjects received one week of cranial nerve non-invasive neuromodulation (CN-NINM). Before and after the week of stimulation, postural sway and fMRI activation were measured to monitor susceptibility to optic flow.

Spatial mapping of electrotactile sensation threshold and intensity range on the human tongue: initial results.

We have developed a novel, tongue-based electrotactile brain-machine interface. Variability of the tactile sensation intensity across the stimulated area, however, limits the amount of reliable information transmission. We have conducted an experiment to characterize local sensitivity across the region stimulated by the array.