A modality-specific somatosensory evoked potential test protocol for clinical evaluation: A feasibility study. Issue 12 (December 2021)

• Record Type: Journal Article
• Authors: Fabig, Sophie-Charlotte; Kersebaum, Dilara; Lassen, Josephine; Sendel, Manon; Jendral, Swantje; Muntean, Alexandra; Baron, Ralf; Hüllemann, Philipp
• Is Part Of: Clinical neurophysiology. Volume 132:Issue 12(2021)
• Page Start: 3104
• Page End: 3115
• Publication Date: 2021-12
• Subjects: Modality-specific evoked potentials -- Sensory nervous system -- Neurophysiological test protocol -- Integrity of the sensory nervous system -- Sensory stratification; PNP polyneuropathy -- EFNS European Federation of Neurological Societies -- SEPs somatosensory-evoked potentials -- AMH II Aδ-fibers with type II mechanical heat-sensitive nociceptors (high mechanical, low heat threshold) -- AMH I Aδ-fibers with type I mechanical heat-sensitive nociceptors (low mechanical, high heat threshold) -- LEPs laser-evoked potentials -- CHEPs contact heat-evoked potentials -- CEPs cold-evoked potentials -- PEPs pinprick-evoked potentials -- TEPs touch-evoked potentials -- ViEPs vibration-evoked potentials -- QST quantitative sensory testing -- EPs evoked potentials -- WEPs warm-evoked potentials -- EEG electroencephalogram -- EOG electrooculography -- NRS numeric rating scale -- ISI inter-stimulus interval -- MOSFET metal oxide semiconductor field effect transistor -- DFNS German Research Network of Neuropathic Pain -- TCS thermal cutaneous stimulator -- DT detection threshold -- PT pain threshold -- ATR Achilles tendon reflex -- SACD subacute combined degeneration of the spinal cord -- TRPV1 transient receptor potential cation channel subfamily V member 1 -- HTMR high-threshold mechanoreceptors; Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2021.08.017
• Languages: English
• ISSNs: 1388-2457

Abstract

Highlights: We present a pilot neurophysiological test protocol for the somatosensory system. Specific fiber subtypes are assessed by their respective modality-specific test. The protocol's applicability is demonstrated in three polyneuropathy patients. Abstract: Objective: We aimed to establish an objective neurophysiological test protocol that can be used to assess the somatosensory nervous system. Methods: In order to assess most fiber subtypes of the somatosensory nervous system, repetitive stimuli of seven different modalities (touch, vibration, pinprick, cold, contact heat, laser, and warmth) were synchronized with the electroencephalogram (EEG) and applied on the cheek and dorsum of the hand and dorsum of the foot in 21 healthy subjects and three polyneuropathy (PNP) patients. Latencies and amplitudes of the modalities were assessed and compared. Patients received quantitative sensory testing (QST) as reference. Results: We found reproducible evoked potentials recordings for touch, vibration, pinprick, contact-heat, and laser stimuli. The recording of warm-evoked potentials was challenging in young healthy subjects and not applicable in patients. Latencies were shortest within Aβ-fiber-mediated signals and longest within C-fibers. The test protocol detected function loss within the Aβ-fiber and Aδ-fiber-range in PNP patients. This function loss corresponded with QST findings. Conclusion: In this pilot study, we developed a neurophysiological test protocol that can specifically assess most of the somatosensory modalities. Despite technical challenges, initial patient data appear promising regarding a possible future clinical application. Significance: Established and custom-made stimulators were combined to assess different fiber subtypes of the somatosensory nervous system using modality-specific evoked potentials.