Rupture of an intracranial aneurysm (IA) causes a systemic response that involves an immune/inflammatory reaction. Our previous study revealed a downregulation of genes related to T lymphocytes and an upregulation of genes related to monocytes and neutrophils after IA rupture. It remains unknown whether that resulted from alterations in transcription or cell count. We sought to characterize the systemic response to IA rupture through analysis of transcript expression profiles in peripheral blood cells. We also investigated effects of IA rupture on the composition of mononuclear cells in peripheral blood. We included 19 patients in the acute phase of IA rupture (RAA, first 72 h), 20 patients in the chronic phase (RAC, 3–15 months), and 20 controls. Using deep transcriptome sequencing, we analyzed the expression of protein-coding and noncoding RNAs. Expression levels, transcript biotypes, alternative splicing and other features of the regulated transcripts were studied. A functional analysis was performed to determine overrepresented ontological groups among gene expression profiles. Flow cytometry was used to analyze alterations in the level of mononuclear leukocyte subpopulations. Comparing RAA and controls, we identified 491 differentially expressed transcripts (303 were downregulated, and 188 were upregulated in RAA). The results indicate that the molecular changes in response to IA rupture occur at the level of individual transcripts. Functional analysis revealed that the most impacted biological processes are related to regulation of lymphocyte activation and toll-like receptor signaling pathway. Differences between RAC and controls were less prominent. Analysis of leukocyte subsets revealed a significantly decreased number of CD4+ lymphocytes and increase of classical and intermediate monocytes in RAA patients compared to controls. IA rupture in the acute phase strongly influences the transcription profiles of peripheral blood cells as well as the composition of mononuclear cells. A specific pattern of gene expression alteration was found, suggesting a depression of lymphocyte response and enhancement of monocyte activity.

BACKGROUND The purpose of our research was to evaluate the relationships between blood viscosity and recanalization of coiled intracranial aneurysms. MATERIAL AND METHODS The study included consecutives patients treated endovascularly by a team of experienced neurosurgeons and neuroradiologists due to brain aneurysm. A total of 50 patients (the average age was 57.48 years, SD=13.71) were assigned to 2 groups: group A with recanalization (4 male and 8 female patients) and group B without recanalization (10 male and 28 female patients) were examined. All patients underwent a 6-month follow-up of the whole-blood viscosity test with a Brookfield DV III+pro cone-plate viscometer using the Rheocalc program. Differences between groups were assessed using the Statistica 12 computer program (StatSoft Inc., Tulsa, OK, USA). RESULTS Studies have shown no significant difference in the age range between group A and B (P=0.31). In group A, higher viscosity values were found for whole blood [median: 4.14 dyn×sec/cm² (mPa×sec) quartile range 0.42], compared to group B [median: 3.92 dyn×sec/cm² (mPa×sec); quartile range 0.40; (P=0.04)]. This difference was significant (P=0.04). Additionally, the level of hematocrit was positively related with recanalization, the higher the hematocrit, the more frequent recanalization. A very strong and statistically significant relationship occurred between the frequency of recanalization and smoking (P<0.001). CONCLUSIONS The occurrence of higher values of whole blood viscosity which increase turbulent flow through the vessels may be a risk for recanalization of the coiled intracranial aneurysm.

Intracranial aneurysm (IA) is a relatively common vascular malformation of an intracranial artery. In most cases, its presence is asymptomatic, but IA rupture causing subarachnoid hemorrhage is a life-threating condition with very high mortality and disability rates. Despite intensive studies, molecular mechanisms underlying the pathophysiology of IA formation, growth, and rupture remain poorly understood. There are no specific biomarkers of IA presence or rupture. Analysis of expression of mRNA and other RNA types offers a deeper insight into IA pathobiology. Here, we present results of published human studies on IA-focused transcriptomics.

Traumatic brain injury (TBI), particularly damage to the frontal lobes, often produces a specific configuration of behavioral and personality changes known as frontal syndrome. Recent data, however, indicate that patients, depending on whether the damage has occurred in the left or right hemisphere of the brain, manifest one of two profiles of this syndrome in which negative or positive behavioral disturbances predominate. The purpose of this study was to evaluate the differences in frontal syndrome profiles present in patients 20 years after injury to the frontal lobes of the right and left hemispheres.The study included a total of 360 patients with brain injury confirmed by neuroimaging studies, rehabilitated at the Reintegration and Training Center of the Polish Neuropsychological Society. The subjects were matched by age and gender into 2 experimental groups: Group A, included 180 patients (including 90 men and 90 women) with post-traumatic frontal lobe damage in the left hemisphere of the brain, and Group B, which included 180 patients (including 90 men and 90 women) with post-traumatic frontal lobe damage in the right hemisphere of the brain. The study employed documentation analysis, clinical interview and the Frontal Syndrome Behavior Questionnaire (FBInv). In accordance with the guidelines of this questionnaire, assessments were made based on an interview with the patient's caregiver in the absence of the patient. The study was conducted twice: two years (baseline) and about 20 years (follow up) after the brain injury.It was found that thepatients with left frontal lobe damage were characterised by significantly higher levels of so-called negative behavioural disorders overall and in the dimensions of apathy, passivity, indifference, concreteness, disorganisation, logopenia, apraxia of speech and perseveration, as well as significantly lower levels of loss of insight. While the patients with right frontal lobe damage were characterised by significantly higher levels of so-called positive conduct disorder overall and in the dimensions of hypersensitivity and irritability, excessive cheerfulness, unreasonable behaviour, inappropriateness and an absence of polite behaviour, aggressiveness, hyper-orality, hyper-sexuality, compulsivity, urinary and faecal incontinence and alien handedness. In addition, it should be noted that most of the recorded effects were found to be strong (η2> 0.14). The results indicated that 20 years after the brain injury, in terms of positive behavioural disorders overall, the group of patients with right frontal lobe damage showed a stronger decrease in disorders (η2= 0.64) over time when compared to patients with left frontal lobe damage (η2= 0.14).We found that in the patients 20 years after post-traumatic damage to the frontal lobes is still manifesting frontal syndrome, however its profile is dependent on whether the damage occurred in the left frontal lobe or the right frontal lobe. The Frontal Syndrome Behavior Questionnaire can be used in the differential diagnosis of frontal syndrome after damage to the frontal lobes of the right and left hemispheres of the brain.