Highlights Muscle weakness after COVID-19 can be caused by critical illness myopathy. Critical illness myopathy should be suspected in patients with long ICU stay. Health systems must plan access to rehabilitative facilities after COVID-19.

The default mode network (DMN) has been consistently activated across a wide variety of self-related tasks, leading to a proposal of the DMN’s role in self-related processing. Indeed, there is limited fMRI evidence that the functional connectivity within the DMN may underlie a phenomenon referred to as self-awareness. At the same time, none of the known studies have explicitly investigated neuronal functional interactions among brain areas that comprise the DMN as a function of self-consciousness loss. To fill this gap, EEG operational synchrony analysis [1, 2] was performed in patients with severe brain injuries in vegetative and minimally conscious states to study the strength of DMN operational synchrony as a function of self-consciousness expression. We demonstrated that the strength of DMN EEG operational synchrony was smallest or even absent in patients in vegetative state, intermediate in patients in minimally conscious state and highest in healthy fully self-conscious subjects. At the same time the process of ecoupling of operations performed by neuronal assemblies that comprise the DMN was highest in patients in vegetative state, intermediate in patients in minimally conscious state and minimal in healthy fully self-conscious subjects. The DMN’s frontal EEG operational module had the strongest decrease in operational synchrony strength as a function of selfconsciousness loss, when compared with the DMN’s posterior modules. Based on these results it is suggested that the strength of DMN functional connectivity could mediate the strength of self-consciousness expression. The observed alterations similarly occurred across EEG alpha, beta1 and beta2 frequency oscillations. Presented results suggest that the EEG operational synchrony within DMN may provide an objective and accurate measure for the assessment of signs of self-(un)consciousness in these challenging patient populations. This method therefore, may complement the current diagnostic procedures for patients with severe brain injuries and, hence, the planning of a rational rehabilitation intervention.

Although several studies propose that the integrity of neuronal assemblies may underlie a phenomenon referred to as awareness, none of the known studies have explicitly investigated dynamics and functional interactions among neuronal assemblies as a function of consciousness expression. In order to address this question, EEG operational architectonics analysis (Fingelkurts and Fingelkurts 2001, 2008) was conducted in patients in minimally conscious (MCS) and vegetative states (VS) to study the dynamics of neuronal assemblies and operational synchrony among them as a function of consciousness expression. We found that in minimally conscious patients and especially in vegetative patients neuronal assemblies got smaller, their life span shortened and they became highly unstable. Furthermore, we demonstrated that the extent/volume and strength of operational synchrony among neuronal assemblies was smallest or even absent in VS patients, intermediate in MCS patients, and highest in healthy fully conscious subjects. All findings were similarly observed in EEG alpha as well as beta1 and beta2 frequency oscillations. The presented results support the basic tenets of operational architectonics theory of brain-mind functioning and suggest that EEG operational architectonics analysis may provide an objective and accurate means of assessing signs of (un)consciousness in patients with severe brain injuries. Therefore, this methodological approach may complement the existing "gold standard" of behavioral assessment of this population of challenging patients and inform the diagnostic and treatment decision-making processes.

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The objective was to assess the changes in cortical excitability after sleep deprivation in normal subjects. Sleep deprivation activates EEG epileptiform activity in an unknown way. Transcranial magnetic stimulation (TMS) can inform on the excitability of the primary motor cortex. Eight healthy subjects (four men and four women) were studied. Transcranial magnetic stimulation (single and paired) was performed by a focal coil over the primary motor cortex, at the "hot spot" for the right first dorsal interosseous muscle. The following motor evoked potential features were measured: (a) active and resting threshold to stimulation; (b) duration of the silent period; (c) amount of intracortical inhibition on paired TMS at the interstimulus intervals of 2 and 3 ms and amount of facilitation at interstimulus intervals of 14 and 16 ms. The whole TMS session was repeated after a sleep deprivation of at least 24 hours. After the sleep deprivation, the threshold to stimulation (in the active and resting muscle), as well as the silent period, did not change significantly. By contrast, the paired stimulus study showed a significant (p<0.05) reduction in both intracortical inhibition and facilitation. Thus, TMS showed that sleep deprivation is associated with changes in inhibitionfacilitation balance in the primary motor cortex of normal subjects. These changes might have a link with the background factors of the "activating" eVects of sleep deprivation. (J Neurol Neurosurg Psychiatry 2001;71:809-812)