A novel sensor design for accurate measurement of facial somatosensation in pre-term infants

Abstract

Facial somatosensory feedback is critical for breastfeeding in the first days of life. However, its development has never been investigated in humans. Here we develop a new interface to measure facial somatosensation in newborn infants. The novel system allows to measure neuronal responses to touching the face of the subject by synchronously recording scalp electroencephalography (EEG) and the force applied by the experimenter. This is based on a dedicated force transducer that can be worn on the finger underneath a clinical nitrile glove and linked to a commercial EEG acquisition system. The calibrated device measures the pressure applied by the investigator when tapping the skin concurrently with the resulting brain response. With this system, we were able to demonstrate that taps of 192 mN (mean) reliably elicited facial somatosensory responses in 7 pre-term infants. These responses had a time course similar to those following limbs stimulation, but more lateral topographical distribution consistent with body representations in primary somatosensory areas. The method introduced can therefore be used to reliably measure facial somatosensory responses in vulnerable infants.

The Emergence of Hierarchical Somatosensory Processing in Late Prematurity

“…N2 emerges over the last trimester of gestation and can be evoked with face, hand and foot stimulation from as early as 31–34 weeks CGA (Hrbek et al 1973; Karniski et al 1992; Taylor et al 1996; Pike et al 1997; Fabrizi et al 2011; Donadio et al 2018). At full-term, it is maximal at the vertex and thought to be generated from bilateral post-central gyrus (Karniski et al 1992).…”

“…P2 emerges over the last trimester of gestation, can be evoked with face, hand, and foot stimulation and, at full-term, is maximal at the vertex (Hrbek et al 1973; Fabrizi et al 2011; Nevalainen et al 2015; Donadio et al 2018). Here, we show that P2 is already established for the upper limbs at 34 weeks CGA, but is still emerging for the lower limbs at this age, providing the first evidence of a rostro-caudal developmental gradient of somatosensory functions in humans.…”

“…Much less is known about longer-latency potentials, which are considered to reflect higher-order processing levels further along the hierarchical tree (Nevalainen et al 2014; Saby et al 2016). At full-term, stimulation of the hands and feet elicits a second negative deflection (N2) at 150 ms following the early N1 and/or P1, and, less consistently reported, a second positive peak (P2) at 240 ms and a third negative peak (N3) at 450 ms (hands: Desmedt and Manil 1970; Hrbek et al 1973; Laget et al 1976; Karniski et al 1992; Taylor et al 1996; Pihko et al 2004; Nevalainen et al 2015; Maitre et al 2017; Donadio et al 2018); feet: (Cindro et al, 1985; Minami et al 1996; Pike et al 1997; Slater et al 2010; Fabrizi et al 2011; Donadio et al 2018). These potentials emerge over the equivalent of the last trimester of gestation (Hrbek et al 1973; Fabrizi et al 2011), but when each tier of the hierarchical chain is established is not known.…”

Event-related potentials following contraction of respiratory muscles in pre-term and full-term infants

“…The first two potentials recorded have comparable topography to potentials recorded in neonates up to 185 ms following bilateral myoclonus (Losito et al 2017) and mechanical somatosensory stimulation of limbs and face, which are somatotopically distributed in pre- and early-term infants (Desmedt and Manil, 1970, Hrbek et al, 1973, Laget et al, 1976, Karniski et al, 1992, Taylor et al, 1996, Pike et al, 1997, Pihko et al, 2004, Tombini et al, 2009, Fabrizi et al, 2011, Nevalainen et al, 2015, Donadio et al, 2018, Whitehead et al, 2019). In older children and adults, perception of respiratory muscle contraction, and other signals from the thoracic cavity, is associated with a sequence of scalp-recorded ERPs across the fronto‐central region lasting until 600 ms post stimulus (Macefield and Gandevia, 1992, Davenport et al, 2000, Frøkjær et al, 2011, Gentsch et al, 2019).…”

Long-range temporal organisation of limb movement kinematics in human neonates

“…2 ) ( Whitehead et al, 2018 ), which refine thalamo-cortical circuits in neonatal animals ( Khazipov et al, 2004 ). However, as infants’ unilateral cortical body maps near completion ( Dall’Orso et al, 2018 , Donadio et al, 2018 ), sensorimotor information associated with bilateral, high-density movements is also important, to strengthen inter- and intra-hemispheric connections ( Whitehead et al, 2019b ), ready for co-ordinated voluntary behaviours like reaching. Here we show for the first time that these distinct forms of sensorimotor information are cyclically organised at this critical juncture of development.…”