Functional and Structural Neural Plasticity Following sEMG Control of a Virtual Prosthetic Hand in an Individual with Bilateral Upper-Limb Congenital Amputation

Abstract

Here we document cortical neural connectivity changes associated with several weeks of prosthetic use in an individual with bilateral upper-limb congenital amputation. Secondly, we explore how those changes relate to prosthetic performance over time. Previous research in unilateral aplasia has shown that functional brain connectivity and activations can be disrupted in the missing hand area, and that prosthetic use can normalize those abnormalities. Functional connectivity and prosthetic use related brain changes in individuals with bilateral congenital upper limb amputations have not been defined. Here, we describe functional and structural connectivity changes measured with MRI after 10-weeks' unilateral use of an sEMG-controlled virtual prosthetic in an individual with aplasia born without either arm. We find that both functional connectivity and structural connectivity change with sEMG prosthetic use. Specifically, functional connectivity of motor regions tends to lateralize and become more hemisphere specific. Additionally, structural connectivity of motor cortico-spinal white matter projections and interhemispheric commissural projections increase after sEMG prosthetic use. These functional connectivity changes are different from those previously reported for one-handed congenital amputees, where prosthetic use normalized, not lateralized, imbalanced interhemispheric motor connectivity. Alongside these neural changes, sEMG virtual prosthetic performance both increased and decreased over time, depending on the action performed. Our results suggest that neural representations of bilateral congenital amputation and subsequent neural adaptions with unilateral prosthetic use may be distinct from those of unilateral congenital and traumatic upper-limb amputees. Consideration of condition-specific neurobiology may be critical in developing effective neuro-prostheses.Clinical Relevance- This describes the neural changes induced by sEMG prosthetic control in a congenital bilateral amputee.