Aberrant Sensory Gating of the Primary Somatosensory Cortex Contributes to the Motor Circuit Dysfunction in Paroxysmal Kinesigenic Dyskinesia

Abstract

Paroxysmal kinesigenic dyskinesia (PKD) is conventionally regarded as a movement disorder (MD) and characterized by episodic hyperkinesia by sudden movements. However, patients of PKD often have sensory aura and respond excellently to antiepileptic agents. PRRT2 mutations, the most common genetic etiology of PKD, could cause epilepsy syndromes as well. Standing in the twilight zone between MDs and epilepsy, the pathogenesis of PKD is unclear. Gamma oscillations arise from the inhibitory interneurons which are crucial in the thalamocortical circuits. The role of synchronized gamma oscillations in sensory gating is an important mechanism of automatic cortical inhibition. The patterns of gamma oscillations have been used to characterize neurophysiological features of many neurological diseases, including epilepsy and MDs. This study was aimed to investigate the features of gamma synchronizations in PKD. In the paired-pulse electrical-stimulation task, we recorded the magnetoencephalographic data with distributed source modeling and time-frequency analysis in 19 patients of newly-diagnosed PKD without receiving pharmacotherapy and 18 healthy controls. In combination with the magnetic resonance imaging, the source of gamma oscillations was localized in the primary somatosensory cortex. Somatosensory evoked fields of PKD patients had a reduced peak frequency (p < 0.001 for the first and the second response) and a prolonged peak latency (the first response p = 0.02, the second response p = 0.002), indicating the synchronization of gamma oscillation is significantly attenuated. The power ratio between two responses was much higher in the PKD group (p = 0.013), indicating the incompetence of activity suppression. Aberrant gamma synchronizations revealed the defective sensory gating of the somatosensory area contributes the pathogenesis of PKD. Our findings documented disinhibited cortical function is a pathomechanism common to PKD and epilepsy, thus rationalized the clinical overlaps of these two diseases and the therapeutic effect of antiepileptic agents for PKD. There is a greater reduction of the peak gamma frequency in PRRT2-related PKD than the non-PRRT PKD group (p = 0.028 for the first response, p = 0.004 for the second response). Loss-of-function PRRT2 mutations could lead to synaptic dysfunction. The disinhibiton change on neurophysiology reflected the impacts of PRRT2 mutations on human neurophysiology.

Cross‐modal relationships of neural gating with the subjective perception of respiratory and somatosensory sensations

“…However, the direction of those relationships was opposite to our expectations, with stronger neural gating of somatosensory sensations (more suppression) relating to higher subjective unpleasantness and intensity. This finding does not easily lend itself to explanation, as it stands in opposition to the theoretical account arrived at from the studies in schizophrenia and other pathologies, where reduced suppression is commonly found to relate to stronger symptom perception (Bak et al, 2017;Chan et al, 2012;Liu et al, 2018;Smucny et al, 2013). One possible explanation for this surprising finding is that our sample consisted of healthy young adults with no reported somatic or psychological complaints.…”

Disruption of gray matter morphological networks in patients with paroxysmal kinesigenic dyskinesia

“…Previous studies have revealed a complex pattern of abnormalities affecting diverse subcortical regions including the basal ganglia and thalamus (Joo et al, 2005; Kim, Kim, Kim, Suh, & Koh, 2015; Shirane, Sasaki, Kogure, Matsuda, & Hashimoto, 2001; Zhou, Chen, Gong et al, 2010; Zhou, Chen, Zhang, et al, 2010), as well as cortical regions including the motor cortex, somatosensory cortex, presupplementary motor area and right inferior frontal gyrus (Hsu, Kwan, et al, 2013; Hsu, Liao, et al, 2013; H. F. Li et al, 2019; Liu et al, 2018) in PKD. However, the pathophysiological mechanisms in PKD are not fully understood.…”

Error-related negativity relates to the neural processing of brief aversive bodily sensations

“…However, literature is lacking in exploring this aspect of the ERN in terms of relationships with the neural signatures of other events fitting this description, such as brief aversive bodily sensations. Instances of such EEG markers of bodily sensations include respiratory-related evoked potentials (RREP; Chan & Davenport, 2010), and somatosensory evoked potentials (SEP; Liu et al, 2018), both constituting stable and consistent evoked potentials that, like the ERN, are known to be affected by anxious states and trait negative affect (Chan, von Leupoldt, Bradley, Lang, & Davenport, 2012;Cheng et al, 2016;Chenivesse et al, 2014;Goffaux et al, 2011). Therefore, we examined potential links between the ERN and the neural correlates of brief, aversive respiratory and somatosensory events in healthy young adults.…”