Detection and multichannel SVD-based filtering of trigeminal somatosensory evoked potentials

Abstract

Very weak and noisy trigeminal somatosensory evoked potentials (TSEPs) are considered, which are successfully evoked by electrical stimulation of the trigeminal nerve of 15 patients with endosseous oral implants. As TSEP analysis provides an objective means of assessing neuronal function, it is considered to be a promising tool for investigating tactile sensation through anchoring implants in bone. For this purpose, a study of TSEP signals acquired from patients with endosseous oral implants has been carried out. Since TSEPs are severely contaminated by background ongoing electrical activities of the brain, a methodology is developed for statistically detecting the transient signal (TSEP) in the biological noise (EEG). For nine out of 15 patients, transient signals are detected in the background EEG activity. The TSEPs of these nine patients are subjected to further analysis. A multichannel singular value decomposition (SVD)-based filtering method is applied which successfully separates out the most energetic TSEPs from the background EEG, thereby increasing significantly the SNR of the recorded signals and improving extraction of the characteristic components of the TSEPs. It is shown that the most prominent feature of the TSEP signals for patients with endosseous oral implants is a wave with peak latency between 9 and 15 ms, generally followed by a wave between 25 and 28 ms or 34 and 38 ms for the specific cortical response areas.

From osseoperception to implant‐mediated sensory‐motor interactions and related clinical implications*

“…By triggering sweeps in the electroencephalogram by means of an implant stimulation device and by cumulating and advanced analysis of the sweeps, one can finally note significant waves. The experiments indicate that it is indeed endosseous and/or periosteal receptors around the implants, which convey the sensation (8, 41).…”

“…Evidence can also be found by non‐invasive approaches for evaluation of oral tactile function. The first approach is the recording of the so‐called trigeminal somatosensory evoked potentials (TSEP) after stimulation of receptors in the oral cavity (7, 8). This set‐up has the advantage of obtaining information on the cortical response of the trigeminal afferent system upon non‐invasive stimulation of oral receptors.…”

“…First, Somatosensory Evoked Potentials (SEPs), which are routinely used to screen for neurological disorders, could assist localizing the origin of sensory phenomena observed upon implant stimulation. For trigeminal SEPs, thorough signal analyses are needed rather than visual inspection, to obtain reliable data on the SEP signals and enable further interpretation on the receptors activated upon implant stimulation (7, 8). A most promising approach is the use of functional Magnetic Resonance Imaging (fMRI), which has the advantage of being a static and/or dynamic imaging technique, without the drawback of exposure to ionizing radiation (9).…”

Vibrotactile evaluation: Osseointegrated versus socket-suspended transfemoral prostheses

“…This suggests that a neurophysiological peripheral feedback pathway can be partly restored [16,[19][20]. Such an assumption is supported by findings showing that two types of stimulation (pressure and strokes by a toothbrush) of an OI thumb prosthesis resulted in cortical activation on both sides of the somatosensory cortex, using functional magnetic resonance imaging of the brain [21].…”

Osseoperception in Dental Implants: A Systematic Review

“…The involvement of the bone innervation in mechanical perceptions is still a controversial subject . The function of bone innervation may be limited to vasoregulatory and bone remodeling processes, whereby most nerve fibers have free nerve endings in the bone connected to the endosteum with vessels or with connective tissue components and may also respond to pressure and pain stimuli . In animal experiments, it has been shown that implant materials are surrounded by nerve fibers in the area of the bone/implant interface .…”