Noninvasive tongue stimulation combined with intensive cognitive and physical rehabilitation induces neuroplastic changes in patients with multiple sclerosis: A multimodal neuroimaging study

Abstract

Background Multiple sclerosis (MS) patients have central nervous system (CNS) lesions that may impede cognitive and sensorimotor function. Few rehabilitative therapies are available. Objectives The objective of this paper is to study effects of noninvasive tongue stimulation using the Portable Neuromodulation Stimulator (PoNS™) combined with intensive cognitive and physical rehabilitation on working memory, gait, balance and concomitant changes in the brain. Methods Fourteen MS patients, seven each in an active and a sham stimulation group, participated. Participants received intensive physical therapy and working memory training for 14 weeks. Functional magnetic resonance imaging (fMRI) using motor imagery and working-memory tasks were completed prior to and following therapy, as were sensory organization tests (SOT), motor performance measures, and neuropsychological assessment. Results On the SOT, the active group showed significant improvement from baseline. fMRI revealed significant blood oxygen level-dependent signal changes in the left primary motor cortex for the Active Group, while the sham group had increased activity in bilateral premotor cortices. All individuals improved on working-memory tasks, but only the active group showed increased dorsolateral prefrontal cortex activity. Conclusions In this cohort of MS patients, the results suggest that PoNS stimulation can enhance motor performance and working memory while also driving neuroplasticity. Further studies are warranted to explore these findings.