Diagnosis of the phenomenon of ‘covert cognition’ in patients with prolonged disorders of consciousness: clinical cases

In recent decades, our understanding of patients with prolonged disorders of consciousness (PDOC) has expanded significantly thanks to the description of the phenomenon of ‘covert cognition.’ An individual approach is important in its diagnosis, involving the comparison of behavioural and instrumental data for each patient. In our country, research into this phenomenon is only just beginning to develop, which makes it important to accumulate cases of successful detection of various ‘covert’ signs of consciousness. This article presents clinical observations of two patients with PDOC. According to clinical assessment using specialised scales, the first patient was in a vegetative state/had unresponsive wakefulness syndrome. Using functional magnetic resonance imaging (fMRI) with a specially designed set of paradigms, the phenomenon of ‘covert cognition’ was detected in her (cerebral activation, partially correlated with the norm, in response to passive somatosensory, auditory non-verbal and verbal stimuli). The second patient, according to the clinical assessment, corresponded to a minimally conscious state ‘minus’. As a result of fMRI examination, instrumental confirmation of the preservation of certain aspects of consciousness (cerebral activation in response to auditory non-verbal and auditory verbal paradigms) was obtained. The use of a comprehensive multimodal personalised approach to the diagnosis of the phenomenon of ‘covert cognition’ and the possibilities of neurorehabilitation of patients based on the data obtained with its help are discussed.

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