Possibilities of endoscopic evaluation of swallowing function in patients with chronic disorders of consciousness

BACKGROUND: The period of coma in some patients after severe brain damage ends with a transition to one of the forms of chronic disorders of consciousness ― a vegetative state/unresponsive wakefulness syndrome or a minimally conscious state. Almost all patients with chronic disorders of consciousness have dysphagia of varying severity, and therefore nutrition of this category of patients is carried out initially through a nasogastric tube, and then through a gastrostomy. Early tracheostomy cannula removal may lead to the development of aspiration and pneumonia. Dysphagia is often not diagnosed in chronic disorders of consciousness patients. AIMS: Analysis of the results of fibrooptic endoscopic assessment of swallowing in chronic disorders of consciousness patients to identify the relationship between the presence and severity of dysphagia with the level of consciousness, data on the coma recovery scale, as well as the duration of consciousness disorders and dynamics of recovery of consciousness. MATERIALS AND METHODS: The study was of a prospective type, conducted in the period from 2019 to 2021. 39 chronic disorders of consciousness patients (18 ― vegetative state/unresponsive wakefulness syndrome, 18 ― minimally conscious state "minus" and minimally conscious state "plus" and 3 patients with a level of consciousness corresponding to the emergence from the minimally conscious state). The average duration of chronic disorders of consciousness was 7.79.4 months. All patients underwent a neurological examination using the CRS-R upon admission to the hospital and a month later, an endoscopic examination of the swallowing function was performed with scores calculated according to the Federal Endoscopic Dysphagia Severity Assessment Scale (FEDSS) and aspiration assessment scale in accordance with the Rosenbek criteria. RESULTS: Dysphagia of varying severity was detected in 36 patients (92.3%). The correlation of the total CRS-R score with the degree of dysphagia (Ro=-0.481, p=0.002) was found. The degree of dysphagia did not depend on the chronic disorders of consciousness duration. CONCLUSION: Regardless of the chronic disorders of consciousness severity (vegetative state/unresponsive wakefulness syndrome, minimally conscious state "minus", minimally conscious state "plus") before tracheostomy removing and switching to the oral feeding, it is necessary to perform fibrooptic endoscopic studies of swallowing to detect dysphagia, determine its degree, which is a method of preventing complications of the decanulation consequences.