Deep Brain Stimulation for Stroke: Continuous Stimulation of the Pedunculopontine Tegmental Nucleus has no Impact on Skilled Walking in Rats After Photothrombotic Stroke

Abstract

Background: Gait impairment after stroke is considered as a loss of cerebral function but is also the result of dysfunctional cerebral signals travelling to the spinal motor centres. A therapeutic option to restore disturbed cerebral network activity is deep brain stimulation (DBS).

Methods: A promising target for neuromodulation might be the pedunculopontine tegmental nucleus (PPTg), which contributes to the initiation and control of gait. To test this hypothesis, we trained eighteen rats to cross a horizontal ladder and a wooden beam before inflicting a photothrombosis in the right sensorimotor cortex and implanting a stimulating electrode in the ipsilateral PPTg.

Results: Continuous high-frequency DBS (130 Hz; amplitude 55 ± 5 μA) of rats for 10 days yielded no significant improvement of skilled walking when examined with the ladder rung walking test and beam walking test compared to sham-stimulation.

Conclusion: In contrast to DBS of the cuneiform nucleus, PPTg-stimulation improves neither control of gait nor balance after stroke.

Keywords: Beam-Walking-Test; Deep brain stimulation; Ladder-Rung-Walking-Test; gait restoration; mesencephalic locomotor region; pedunculopontine tegmental nucleus; photothrombotic stroke.