Chronic post‐stroke oropharyngeal dysphagia is associated with impaired cortical activation to pharyngeal sensory inputs

Abstract

Chronic post-stroke oropharyngeal dysphagia is associated with stroke severity and degree of leukoaraoisis. Impaired conduction and cortical integration of pharyngeal sensory inputs at stroke site are key features of chronic PSD. These findings highlight the role of sensory pathways in the pathophysiology of post-stroke oropharyngeal dysphagia and offer a potential target for future treatments.

Effect of a gum‐based thickener on the safety of swallowing in patients with poststroke oropharyngeal dysphagia

“…Such a delay in time to LVC in PSOD associated with impaired safety of swallow was also observed in this study, almost doubling the time to LVC of healthy people, and was slightly above that previously described in comparable patients . Reduced pharyngeal sensitivity and impaired conduction and cortical integration of pharyngeal sensory inputs at the stroke site is a key feature of chronic PSOD and has been closely associated with impaired safety of swallow and delayed time to LVC . In fact, sensory feedback from the bolus is critical to tailor the motor component of the swallow response.…”

“…While some patients recover spontaneously, 50% assessed 6 months poststroke were found to have chronic OD . The pathophysiology of PSOD is characterized by several motor impairments in the kinematics of the swallow response including delayed laryngeal vestibule closure (LVC) and decreased bolus propulsion forces ; also, patients affected by unilateral stroke showed a disrupted pattern of sensory cortical activation after pharyngeal stimulation as a distinctive marker of abnormal sensory integration of swallowing pathways in PSOD …”

“…The primary objective was to assess the percentage of patients that could swallow safely at each of the three main viscosities (2000, 800 or 250 mPa s) compared with thin liquid. Secondary and exploratory objectives were to assess the effect of all viscosities on penetrations, aspirations, the Penetration‐Aspiration Scale (PAS) developed by Rosenbek, the presence and severity of oral and pharyngeal residue, and the effects on the biomechanics of the swallow response …”

Prevalence, risk factors and complications of oropharyngeal dysphagia in stroke patients: A cohort study

“…In a previous independent study, we found that chronic poststroke OD was associated with stroke severity and the degree of leukoaraiosis present. In that study, we found that impaired conduction and cortical integration of pharyngeal sensory inputs at the stroke site were key features of poststroke OD, We also found that impaired safety of swallow in chronic poststroke patients was caused by specific impairments in the motor swallow response, including delayed timing of airway protection mechanisms and weak tongue propulsion forces …”

Cold thermal oral stimulation produces immediate excitability in human pharyngeal motor cortex

“…It has been demonstrated that the application of sensory stimulation in oropharyngeal area modulates swallowing performance and involves facilitation of swallowing initiation Sensory impairments in pharyngeal area are associated with penetration or aspiration in dysphagic patients, and oropharyngeal anesthesia results in disruption of swallowing movement even in healthy humans . Furthermore, impaired pharyngeal sensitivity is associated with reduced cortical activation …”