[The cholinergic deficiency syndrome in patients with depressed consciousness after severe brain injury]. / Sindrom kholinergicheskoi nedostatochnosti pri dlitel'nom ugnetenii soznaniya posle tyazheloi cherepno-mozgovoi travmy.

AIM: To determine the clinical and electrophysiological (EEG) signs of cholinergic deficiency in the process of recovery of consciousness in patients with severe brain injury. MATERIAL AND METHODS: Thirty-seven people (24 men and 13 women, mean age 32±14 years) were studied. A comprehensive study included assessment of neurological status, mental activity, and EEG. RESULTS AND CONCLUSION: A set of neurological symptoms, including reduced muscle tone, autonomic disorders (dry mucous membranes and skin, tachycardia, hypotension, gastrointestinal tract), eye movement disorders, that were,in accordance with the literature, characteristicof the cholinergic deficiency syndrome was found. This syndrome was detected against the background of a comatose state, akinetic mutism and mutism with understanding of speech, disintegration of speech, disorientation and amnestic decline. EEG revealed stable over time (months) characteristic changes: slowing and asymmetric alpha activity, equivalent dipole sources of hippocampal and stem localization, persistent strengthening of intra-hemispheric coherent connections, especially on the left side. The regression of the cholinergic deficiency syndrome was accompanied by an increase of regularity, capacity and frequency of alpha-activity (from 7-8 to 9-10 Hz), prevalence of equivalent dipole sources in the hippocampus with their appearance in the occipital cortex, normalization of connections with right-brain coherence with the preservation of their pathologically high values on the left side.

[Clinical/encephalographic syndrome of dopamine deficiency in patients with depressed consciousness after severe brain injury].

OBJECTIVE: To determine electroencephalographic signs of dopamine deficiency syndrome during the recovery after severe brain injury (SBI). MATERIAL AND METHODS: We studied 35 patients with SBI (23 men and 12 women, mean age 29 ± 13 years). RESULTS AND CONCLUSION: We identified a set of neurological symptoms (increased muscular tone of extrapyramidal type, rest tremor, autonomic disorders, which were most characteristic of the autonomic state, and some forms of mutism associated, according to current conceptions, with the dopaminergic system deficiency syndrome. This clinical picture was accompanied by stable EEG changes: an increase in the severity of beta activity of 13-14 Hz, enhanced in the frontal and anterior temporal areas, synchronized with equivalent dipole source localization in subcortical and frontal/basal areas. Dopamine deficiency regression syndrome was accompanied by an increase in beta EEG activity (from 13 to 16 Hz), but with the persistent abnormal enhancement of coherent hemispheric relations, especially in the occipital-temporal areas.

[EEG-correlates of consciousness recovery after traumatic brain injury].

The aim of studies of patients in long-term posttraumatic unconscious state (PUS) was to outline prognostically significant EEG-markers of consciousness condition and an assessment of its dynamics orientation. We analysed outcomes of dynamic (from days to 16 years after trauma) EEG studies in 196 patients in TBI-caused PUS and different degrees of mental recovery: from chronic unconscious state up to clear consciousness. These results were compared to clinical protocols and data of MRI. It is revealed that dynamic features of EEC pattern (with the analysis of equivalent dipolar sources of separate components) allow to characterize the severity of patient's current state, to reveal the brain structures with the most expressed dysfunction, to define a zone of local cortical damage, and also the general direction of development of a traumatic illness (as though dynamics of a homeostasis of a brain). Frequency characteristics of EEG power spectrum (average frequency--an effective frequency strip) in a background and at reactions find the greatest predictive importance, especially at their assessment in 2-3 months after a trauma. The background interhemispheric EEG coherence (first of all, frontal) as the integrative characteristic of system brain activity, and its change at reactions to external incentives most reflect degree of consciousness oppression, dynamics and potential of its restoration. It was shown the high informational of the researches EEG changes to indifferent and functionally significant signs for an assessment of CNS functionality, and also of PUS pathogenesis.