The difficulties of behavioral evaluation of prolonged disorders of consciousness (DOC) motivate the development of brain-based diagnostic approaches. The perturbational complexity index (PCI), which measures the complexity of electroencephalographic (EEG) responses to transcranial magnetic stimulation (TMS), showed a remarkable sensitivity in detecting minimal signs of consciousness in previous studies. Here, we tested the reliability of PCI in an independently collected sample of 24 severely brain-injured patients, including 11 unresponsive wakefulness syndrome (UWS), 12 minimally conscious state (MCS) patients, and 1 emergence from MCS patient. We found that the individual maximum PCI value across stimulation sites fell within the consciousness range (i.e., was higher than PCI*, which is an empirical cutoff previously validated on a benchmark population) in 11 MCS patients, yielding a sensitivity of 92% that surpassed qualitative evaluation of resting EEG. Most UWS patients (n = 7, 64%) showed a slow and stereotypical TMS-EEG response, associated with low-complexity PCI values (i.e., ≤PCI*). Four UWS patients (36%) provided high-complexity PCI values, which might suggest a covert capacity for consciousness. In conclusion, this study successfully replicated the performance of PCI in discriminating between UWS and MCS patients, further motivating the application of TMS-EEG in the workflow of DOC evaluation.

The diagnostic value of white matter hyperintensities (WMH) in different types of migraineare unknown. To evaluate the WMH pattern of different subtypes in migraine patients with no vascular risk factors. 92 migraine patients (73 females, mean age 34.6 ± 8.9; 61 episodic migraine, 31 chronic migraine, 36 migraine with aura, 56 migraine without aura) without vascular risk factors underwent brain MRI (3 T). We also included a matched healthy control group with no migraine (n = 24). The prevalence of WMH in different types of migraine was similar and ranged from 38.7 to 44.4%; the control group showed no WMH at all. Lesions were located within frontal, parietal and temporal lobes (in order of decreasing incidence) in juxtacortical and/or deep white matter. WMH appeared as round or slightly elongated foci with a median size of 2.5 mm [1.5; 3]. Total number, size and prevalence of WMH by lobes and white matter regions were similar between groups, and no interaction with age or sex was found. The number of lesions within the frontal lobe juxtacortical white matter correlated with the age of patients (r = 0.331, p = 0.001) and the duration since migraine onset (r = 0.264, p = 0.012). Patients with different migraine subtypes and without vascular risk factors are characterized by a similar pattern of WMH in the absence of subclinical infarctions or microbleedings. Therefore, WMH have no relevant prognostic value regarding the course of migraine and vascular complications. WMH pattern may be used to differentiate migraine as a primary disorder and other disorders with migraine-like headache and WMH.

Cerebral small vessel disease (SVD) is a major cause of cognitive impairment in elderly people. While most research focuses on the role of the classical vascular risk factors in SVD, a description of the psychophysiological mechanisms leading to the age-related brain damage may open new possibilities for prophylaxis. In the current study, we evaluated the associations between emotional abilities, interoception, and age-related vascular white matter degeneration. The work was influenced, first, by multiple studies recognizing alexithymia as a cardiovascular risk factor; second, by theories of emotions linking body's allostasis and emotional regulation; and third, by neuroimaging data highlighting the shared role of the insular cortex in interoceptive and emotional processing. In a sample of older female adults (N = 30), we performed the Mayer-Salovey-Caruso Emotional Intelligence Test, functional MRI using the heartbeat detection task, and evaluation of white matter microstructural integrity using diffusion weighted imaging. The ability to understand and analyze emotions-one of the four components of emotional intelligence-was found to be associated with higher interoception-related activation of the right anterior insula and preserved white matter microstructure. We interpret these results in light of the concept of Embodied Predictive Interoception Coding, which proposes that emotional processing, interoception, and allostasis (antecedent top-down regulation of the body's internal milieu) may rely on the shared neural mechanisms of predictive coding. The study demonstrates feasibility of the investigation of cerebrovascular diseases form a psychophysiological perspective and calls for future research.

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Introduction. White matter hyperintensity (WMH) is a neuroimaging age-related phenomenon associated with an increased cardiovascular risk in people with arterial hypertension (AH). The prevalence of WMH and its relationship with risk factors for cerebrovascular disease (CVD) in middle-age population requires clarification. Aim: to assess the prevalence of the WMH phenomenon in people of working age (40–59 years) and to establish cerebrovascular risk factors associated with its development. Material and methods. Study cohort (n = 376; 156 (41.5%) men and 220 (58.5%) women; mean age 49.7 ± 5.0 years) was formed by screening an open population (40–59 years of age). Using a questionnaire and clinical, laboratory and instrumental findings, including brain MRI (1T), the prevalence of cardiovascular and cerebrovascular risk factors was analyzed. The odds ratio (OR) of the event occurring and a 95% confidence interval were calculated. Results. High prevalence of risk factors was revealed in the age group of 40–59 years, including AH in 46.7%, increased body mass index (BMI) in 60.6%, dyslipidemia (up to 39%), metabolic syndrome in 21.5%, thickening of the intima-media complex in 57.2%, atherosclerotic plaques in 49.7% of all cases. WMH was identified in 32% (120/376) of the subjects examined. An association between presence, severity of WMH and age, presence and severity of AH, as well as total burden of vascular risk factors was established. The most significant factors associated with the development of WMH in people aged 40–59 were found to be AH (OR 3.35), atherosclerosis of the brachiocephalic arteries (OR 1.79), and hyperglycemia (OR 1.36). Conclusion. Thus, there is a high prevalence of risk factors for cardiovascular and cerebrovascular diseases in the working-age population of the megalopolis (Moscow) at the age of 40–59 years, which is associated with accelerated WMH formation. Significant factors that are associated with WMH are AH, atherosclerosis of the brachiocephalic arteries, hyperglycemia, as well as dyslipidemia and metabolic syndrome. Early detection and management of the listed modifiable risk factors are necessary to prevent the development and progression of cerebral injury.

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Introduction. Rapid advances in critical care medicine have led to an increased survival rate of patients with severe brain damage and, consequently, to an increased prevalence of chronic disorders of consciousness (CDC). The lack of or fluctuations in signs of consciousness, which accompany the restoration of alertness after recovery from coma, indicate whether the type of CDC is a vegetative state or minimally conscious state. Correct diagnosis determines not only the rehabilitation outcome but also the economic outlook for a particular patient. However, the subjective nature of signs of consciousness, which are identified during clinical examination using neurological scales, is a common cause of diagnostic errors. The study of spontaneous activity using resting-state functional magnetic resonance imaging (fMRI) has helped to identify resting state networks. The default mode network (DMN) is one of the most studied brain networks. Its signal can change or be absent in patients with various types of CDC. Purpose. To study the signal of residual spontaneous brain activity in patients with CDC at rest. Materials and methods. Twenty-two patients with permanent CDC underwent resting state fMRI as an additional tool in the differential diagnosis between vegetative state and minimally conscious state at the Research Centre of Neurology. Results. It was found that the nature of the signal coming from anatomical regions that are part of the DMN changes when signs of consciousness emerge. Conclusion. These changes confirm that resting state fMRI is an important additional tool for differential diagnosis of CDC types. Accumulating knowledge about the brain's functional state helps us to expand our overall understanding of the nature of consciousness.