Safety and efficacy of simple training protocol in patients after mild traumatic brain injury.

AIMS: Mild Traumatic Brain Injury (mTBI) is the most common type of craniocerebral injury. Proper management appears to be a key factor in preventing post-concussion syndrome. The aim of this prospective study was to evaluate the effect and safety of selected training protocol in patients after mTBI. METHODS: This was a prospective study that included 25 patients with mTBI and 25 matched healthy controls. Assessments were performed in two sessions and included a post-concussion symptoms questionnaire, battery of neurocognitive tests, and magnetic resonance with tractography. Participants were divided into two groups: a passive subgroup with no specific recommendations and an active subgroup with simple physical and cognitive training. RESULTS: The training program with slightly higher initial physical and cognitive loads was well tolerated and was harmless according to the noninferiority test. The tractography showed overall temporal posttraumatic changes in the brain. The predictive model was able to distinguish between patients and controls in the first (AUC=0.807) and second (AUC=0.652) sessions. In general, tractography had an overall predictive dominance of measures. CONCLUSION: The results from our study objectively point to the safety of our chosen training protocol, simultaneously with the signs of slight benefits in specific cognitive domains. The study also showed the capability of machine learning and predictive models in mTBI patient recognition.

A high-throughput liquid chromatography-tandem mass spectrometry method for simultaneous determination of direct oral anticoagulants in human plasma.

Direct oral anticoagulants are widely used in many indications to prevent thromboembolic events. Routine therapeutic monitoring is not required; however, there is increasing evidence suggesting the benefit of plasma level measurement in some situations. In addition, laboratory monitoring might help improve patient and drug non-compliance and thus individualize therapy. In the present study, we developed a sensitive and high throughput ultra-high-performance liquid chromatography-tandem mass spectrometry method for simultaneous quantification of apixaban, dabigatran, edoxaban, and rivaroxaban in human plasma. A one-step extraction procedure in 96-well formate for phospholipid and protein removal was used for sample pre-treatment, and analytes were separated using gradient elution over 4.2 min. Analytes were detected on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring mode. The method was validated according to the European Medicine Agency guideline for the selectivity, linearity, and lower limit of detection, precision and accuracy, matrix effects, extraction recovery, carryover, dilution integrity, and stability over a concentration range of 3.0-1000 ng/ml for all analytes. The validated method was applied to real clinical samples of patients treated with one of the drugs. Therefore, we can conclude that our method is suitable for therapeutic drug monitoring of direct oral anticoagulants.

Information-processing speed in mildly disabled relapsing-remitting multiple sclerosis patients correlates with volumetry of optic chiasma and subcortical grey matter nuclei.

INTRODUCTION: Multiple sclerosis (MS) is an inflammatory demyelinating disease leading not only to physical disability but also to cognitive dysfunction. The aim of our study was to test cognitive functions of MS patients with mild relapsing-remitting form and to find out the relationship between cognitive functions and brain volumetry. METHODS: 52 patients (RRMSp) and 23 age-related healthy participants (CON) were enrolled. Mild disability was defined by mean EDSS 2.4 (≤ 4.0), and by median of disease duration 5.2 years. Cognitive status was tested using Single Digit Modality Test (SDMT). Brain volumetry was processed in FreeSurfer 2.0.0. RESULTS: RRMSp patients showed significantly lower SDMT score than CON. SDMT results correlated positively with volume of thalamus, putamen and nc. caudate, and negatively with optic chiasma volume. Compared with CON, RRMSp presented with significantly lower volume in left and right nc. accumbent, cuneus and insular GM, right putamen, total brain cortical grey matter (GM), white matters hypointensities, and 3rd ventricular widths. CONCLUSION: To our best knowledge, this is the first study that presents results showing a correlation of lower SDMT with higher optic chiasma volume, due to its subclinical chronic demyelination. We confirmed that GM atrophy is involved in cognitive functions in MS (Tab. 3, Fig. 2, Ref. 73).

Modeling and simulation of vagal afferent input of the cough reflex.

We employed computational modeling to investigate previously conducted experiments of the effect of vagal afferent modulation on the cough reflex in an anesthetized cat animal model. Specifically, we simulated unilateral cooling of the vagus nerve and analyzed characteristics of coughs produced by a computational model of brainstem cough/respiratory neuronal network. Unilateral vagal cooling was simulated by a reduction of cough afferent input (corresponding to unilateral vagal cooling) to the cough network. All these attempts resulted in only mild decreases in investigated cough characteristics such as cough number, amplitudes of inspiratory and expiratory cough efforts in comparison with experimental data. Multifactorial alterations of model characteristics during cough simulations were required to approximate cough motor patterns that were observed during unilateral vagal cooling in vivo. The results support the plausibility of a more complex NTS processing system for cough afferent information than has been proposed.

Plasma levels of direct oral anticoagulants in atrial fibrillation patients at the time of embolic stroke: a pilot prospective multicenter study.

BACKGROUND: Patients with atrial fibrillation (AF) who are on long-term direct oral anticoagulants (DOAC) with low anti-Xa or anti-IIa levels may be at higher risk of recurrent stroke. However, no prospective post-marketing study has investigated these DOAC plasma levels at the time of embolic stroke. The aim of this study was to assess the anti-Xa (rivaroxaban, apixaban) and anti-IIa (dabigatran) plasma levels in DOAC-treated AF patients at the time of acute embolic stroke. PATIENTS AND METHODS: We prospectively identified 43 patients with AF on long-term DOAC who experienced embolic strokes. We compared the DOAC plasma levels of these patients with a control sample of 57 patients who tolerated long-term therapeutic dose DOAC therapy without any adverse event. DOAC levels were assessed with drug-specific anti-Xa chromogenic analysis (rivaroxaban, apixaban) and with Hemoclot Thrombin Inhibitor assay (dabigatran). RESULTS: Dabigatran-treated patients with stroke had significantly lower anti-IIa levels when compared with the trough (40.7 ± 36.9 vs. 85.4 ± 57.2 ng/mL, p < 0.05) and peak samples of the controls (40.7 ± 36.9 vs. 138.8 ± 78.7 ng/mL, p < 0.001). Similarly, there were significantly lower anti-Xa levels in apixaban-treated patients with stroke compared to the trough control samples (72.4 ± 46.7 vs. 119.9 ± 81.7 ng/mL, p < 0.05), and in rivaroxaban- and apixaban-treated patients when compared to peak control samples (rivaroxaban: 42.7 ± 31.9 vs. 177.6 ± 38.6 ng/mL, p < 0.001; apixaban: 72.4 ± 46.7 vs. 210.9 ± 88.7 ng/mL, p < 0.001). CONCLUSION: This observational study showed significantly lower anti-IIa and anti-Xa plasma levels in AF patients with embolic stroke compared to those who tolerated long-term therapeutic dose DOAC therapy.

Volume feedback during cough in anesthetized cats, effects of occlusions and modulation summary.

The study investigates the effects of 6 occlusion conditions on the mechanically induced cough reflex in 15 anesthetized (pentobarbital) spontaneously breathing cats (14♂, 1♀). Esophageal pressure and integrated EMG activities of inspiratory (I) diaphragm and expiratory (E) abdominal muscles were recorded and analyzed. Occlusions: inspiratory (Io), continual I (cIo), during I and active E (I+Eo) cough phase, during I and then E phase with short releasing of airflow before each phase (I-Eo), and E occlusion (Eo) had little influence on cough number. Only continual E occlusion (cEo) reduced the number of coughs by 19 % (to 81 %, p < 0.05). Cough I esophageal pressure reached higher amplitudes under all conditions, but only Eo caused increased I diaphragm motor drive (p < 0.05). Cough E efforts (abdominal motor drive and E amplitudes of esophageal pressure) increased during Eo, decreased during I+Eo (p < 0.05), and did not change significantly under other conditions (p > 0.05). All I blocks resulted in prolonged I cough characteristics (p < 0.05) mainly cough I phase (incrementing part of the diaphragm activity). Shorter I phase occurred with cEo (p < 0.05). Cough cycle time and active E phase (from the I maximum to the end of cough E motor drive) prolonged (p < 0.05) during all occlusions (E phase duration statistically non-significantly for I+Eo). Airflow block during cough (occlusions) results in secondary changes in the cough response due to markedly altered function of cough central pattern generator and cough motor pattern produced. Cough compensatory effects during airflow resistances are more favorable compared to occlusions. Volume feedback represents significant factor of cough modulation under various pathological obstruction and/or restriction conditions of the respiratory system.

Changes in vagal afferent drive alter tracheobronchial coughing in anesthetized cats.

Unilateral cooling of the vagus nerve (<5°C, blocking mainly conductivity of myelinated fibers) and unilateral vagotomy were employed to reduce cough afferent drive in order to evaluate the effects of these interventions on the temporal features of the cough reflex. Twenty pentobarbitone anesthetized, spontaneously breathing cats were used. Cough was induced by mechanical stimulation of the tracheobronchial airways. The number of coughs during vagal cooling was significantly decreased (p<0.001). Inspiratory cough efforts were reduced by approximately 30% (p<0.001) and expiratory motor drive by more than 80% (p<0.001). Temporal analysis showed prolonged inspiratory and expiratory phases, the total cycle duration, its active portion, and the interval between maxima of the diaphragm and the abdominal activity during coughing (p<0.001). There was no significant difference in the average effects on the cough reflex between cooling of the left or the right vagus nerve. Compared to control, vagal cooling produced no significant difference in heart rate and mean arterial blood pressure (p>0.05), however, cold block of vagal conduction reduced respiratory rate (p<0.001). Unilateral vagotomy significantly reduced cough number, cough-related diaphragmatic activity, and relative values of maximum expiratory esophageal pressure (all p<0.05). Our results indicate that reduced cough afferent drive (lower responsiveness) markedly attenuates the motor drive to respiratory pump muscles during coughing and alters cough temporal features. Differences in the effects of unilateral vagal cooling and vagotomy on coughing support an inhibitory role of sensory afferents that are relatively unaffected by cooling of the vagus nerve to 5°C on mechanically induced cough.