P300 latency changes in patients with mild cognitive impairment after taking choline alphoscerate; A preliminary study

Solubility determination and thermodynamic model analysis of L-α-glyceryl phosphorylcholine in different organic solvents of 278.15 K to 323.15 K

L-α-glyceryl phosphorylcholine, also referred to as choline ethanol phosphate and phosphocholine glycerophosphate, is a naturally occurring metabolite of water-soluble phospholipids in animals. This molecular property is important for informing the crystallization and purification of drugs. The solubility of L-α-glyceryl phosphorylcholine was determined in ten pure solvents and three mixed solvents under atmospheric pressure. The experimental results indicate that L-α-glyceryl phosphorylcholine is most soluble in methanol and least soluble in acetone. Additionally, the solubility of L-α-glyceryl phosphorylcholine was found to increase with temperature within the experimental range. Furthermore, the solubility of L-α-glyceryl phosphorylcholine in binary solvents is dependent on the proportion of positive solvent and temperature. The solubility of L-α-glyceryl phosphorylcholine increases with the proportion of positive solvent. XRD and DSC results indicate that the crystal form of L-α-glyceryl phosphorylcholine remains unchanged before and after dissolution in the reagent, and its melting point temperature is 413.15 K. Various models, including the modified Apelblat model, λh model, Jouyban-Acree model, SUN model, and CNIBS/R-K model, were used to fit the solubility data of L-α-glyceryl phosphorylcholine in different solvents. The study found that the modified Apelblat model and CNIBS/R-K model were the most appropriate for fitting the data. The KAT-LSER model was used to analyze the molecular interactions between solvents and solutes, revealing that the solvent step method with non-specific polarity/polarization interaction had the greatest impact on solubility.

The Effects of Directional and Non-Directional Stimuli during a Visuomotor Task and Their Correlation with Reaction Time: An ERP Study

Different visual stimuli can capture and shift attention into different directions. Few studies have explored differences in brain response due to directional (DS) and non-directional visual stimuli (nDS). To explore the latter, event-related potentials (ERP) and contingent negative variation (CNV) during a visuomotor task were evaluated in 19 adults. To examine the relation between task performance and ERPs, the participants were divided into faster (F) and slower (S) groups based on their reaction times (RTs). Moreover, to reveal ERP modulation within the same subject, each recording from the single participants was subdivided into F and S trials based on the specific RT. ERP latencies were analysed between conditions ((DS, nDS); (F, S subjects); (F, S trials)). Correlation was analysed between CNV and RTs. Our results reveal that the ERPs' late components are modulated differently by DS and nDS conditions in terms of amplitude and location. Differences in ERP amplitude, location and latency, were also found according to subjects' performance, i.e., between F and S subjects and trials. In addition, results show that the CNV slope is modulated by the directionality of the stimulus and contributes to motor performance. A better understanding of brain dynamics through ERPs could be useful to explain brain states in healthy subjects and to support diagnoses and personalized rehabilitation in patients with neurological diseases.

Validated quantitative 31P NMR spectroscopy for positional isomeric impurity determination in L-α-glycerylphosphorylcholine (L-α-GPC)

In this study a quantitative ³¹P nuclear magnetic resonance (³¹P NMR) spectroscopy method was described to determine positional isomeric impurity β-GPC in commercial products of L-α-GPC. The samples were dissolved in D₂O and trimethyl phosphate (TMP) was selected as an internal calibrant. The measurements were performed on a Bruker 500 MHz spectrometer and the spectra were recorded under optimized process conditions. A good linear relationship was constructed for β-GPC in the range of 62.7-528.0 µg·mL^-1, i.e. 0.03-0.25 % (w/w %, in relative to L-α-GPC) with a correlative coefficient of 0.9996. The limit of quantification (LOQ) and limit of detection (LOD) were 62.7 µg·mL^-1 and 20.9 µg·mL^-1 with signal to noise of 3 and 10, respectively. The spiked recoveries were in the range of 98.17-99.78 % with the relative standard deviation (RSD %) less than 1.0 %. Therefore, it could be supposed that the ³¹P NMR was a promising alternative method for sensitive determination of β-GPC for strict quality control of L-α-GPC.

Quantitative electroencephalography changes in patients with mild cognitive impairment after choline alphoscerate administration

There is limited evidence on the effectiveness of choline alphoscerate for mild cognitive impairment (MCI) in studies using neuropsychological markers. The aim of this study was to evaluate the spectral change at a source level using quantitative electroencephalography (qEEG) as a biomarker for cognitive function after choline alphoscerate administration to patients with MCI. This study used the qEEG data of patients with MCI who visited the Department of Neurology of the Chung-Ang University Hospital between April 2017 and December 2018. Resting-state EEG studies were performed on 33 patients with MCI at baseline and compared with those of the 18 normal controls selected from the community. After baseline qEEG, choline alphoscerate 400 mg was administered twice daily for 2 months to the patients with MCI. Follow-up qEEG was performed in 20 subjects. Baseline qEEG of patients with MCI was compared to qEEG after choline alphoscerate administration. We found that the MCI group exhibited a decreased alpha power compared to that of the control group. Patients with MCI treated with choline alphoscerate exhibited a decrease in the theta and delta power of the parietal and temporal lobe and an increase in the alpha power spectrum of the occipital lobes. We also identified the trend of default mode network enhancement after choline alphoscerate administration. Our results suggest that choline alphoscerate may have a positive effect in patients with MCI and support the usefulness of qEEG for monitoring the therapeutic effect of nootropics.

Improvement of poststroke cognitive impairment by intermittent theta bursts: A double-blind randomized controlled trial

BACKGROUND

Intermittent theta burst stimulation (iTBS) is known to improve cognitive impairment caused by Alzheimer's disease and Parkinson's disease, but studies are lacking with respect to the efficacy of iTBS on poststroke cognitive impairment (PSCI).

OBJECTIVE

This study was conducted to investigate the effect of left dorsolateral prefrontal cortex (DLPFC) iTBS on improving cognitive function in stroke patients.

METHODS

Fifty-eight patients with PSCI are randomly divided into iTBS (n = 28) and sham stimulation groups (n = 30). Both groups receive routine cognitive-related rehabilitation. The iTBS group is treated with iTBS intervention of the left DLPFC, and the sham stimulation group is treated with the same parameters at the same site for 2 weeks. Outcome measures are assessed at baseline (T0) and immediately after the last intervention (T1) by mini-mental state examination (MMSE), Oxford cognitive screen, and event-related potential P300.

RESULTS

There are no differences in baseline clinical characteristics between the two groups. After intervention, the MMSE scores and P300 amplitude increase significantly for both groups, and the P300 incubation period reduces significantly. The change value of the iTBS group is significantly higher than that of sham stimulation group (p < .05). Compared with the sham stimulation group, the iTBS group has more significant changes in semantic comprehension and executive function (p < .05).

CONCLUSION

iTBS can effectively and safely improve overall cognitive impairment in stroke patients, including semantic understanding and executive function, and it also has a positive impact on memory function. Future randomized controlled studies with large samples and long-term follow-up should be conducted to further validate the results of the present study.

Application of the P300 potential in cognitive impairment assessments after transient ischemic attack or minor stroke

Background The aims of this study were to determine the relationships between changes inlatency and amplitude of the P300 event-related potential component and cognitive impairmentsin patients after a transient ischemic attack (TIA) or a minor stroke and to assess thesuitability of the P300 for screening for cognitive impairments.Material and Method Sixty-five TIA or minor stroke patients diagnosed at the NeurologyDepartment of Beijing Tiantan Hospital, Capital Medical University from June 2015 toDecember 2016 and 30 healthy people evaluated in the same period were included. Allpatients were examing neuropsychological scales and event-related potentials within7 ± 3 days of onset of the disease. The TIA/minor stroke group was divided into normal cognition group(NC) and cognitive impairment group. The cognitive impairment group was further divided into vascular cognitive impairment with no dementia(VCIND) group and vascular dementia (VD) group to analyze the relationship between P300 latency.Results The P300 latency at each recording electrode was longer in the NC and VCIND groups than healthy control group (P < 0.001), the P300 latency of VCIND group longer than NC group (P < 0.001). When the P300-Fz latency cut-off value was 358.6 ms,the sensitivity for diagnosing cognitive impairment in patients after TIA/minor stroke was 0.875 and the specificity was 0.765.Conclusions The P300 latency delay can be used to detect cognitive impairments in patients after TIA/minor stroke and the P300-Fz latency is more sensitive for diagnosing cognitiveimpairments in TIA/minor stroke patients.

Intrinsic stability study of L-α-glycerylphosphorylcholine with HPLC method development and validation

L-α-Glycerylphosphorylcholine (L-α-GPC) is effective to control the symptoms of cognitive decline for the patients of Alzheimer's disease. In this study, an HPLC method coupled with a refractive index detector was developed to evaluate the intrinsic stability of L-α-GPC. The separation of L-α-GPC and its major potential degradation products was achieved on a normal-phase silica gel column (4.6 mm × 250 mm) with the mobile phase consisting of methanol-20 mM ammonium formate aqueous solution (pH 3.2) (65:35, v/v) in isocratic mode. The HPLC method was validated satisfactorily with respect to precision, accuracy and robustness. It is found that L-α-GPC is stable under the photolytic, thermal, oxidative and acidic conditions, while relatively sensitive to alkaline condition due to the specific breakage of phosphate ester bond in the moiety of L-α-GPC. A preliminary kinetics study for the alkaline degradation was conducted with the corresponding kinetics parameters obtained. It can be concluded that the developed HPLC method is capable of distinguishing the stability difference between the two phosphate ester bonds characterized on the L-α-GPC chemical structure.