The Neurocognitive effects of Lacprodan(Registered Trademark) PL-20 in elderly participants with age-associated memory impairment.

INTERVENTION: Lacprodan(Registered Trademark) PL‐20 is a fat‐reduced cream powder manufactured by Arla Foods Ingredients P/S, Denmark. In comparison to regular cream powder Lacprodan(Registered Trademark) PL‐20 is enriched in protein and phospholipids, while its triglyceride and lactose content is reduced. Lacprodan(Registered Trademark) PL‐20 will be administered orally at a maximum dose of 16g/day, providing minimum daily dosages of 2.7g total phospholipids and 300mg phosphatidylserine (PS). Lacprodan will be administered as a powder dissolved in <=250mL water and drunk once per day with breakfast for 180 days (6 moinths). The Phospholipid composition of Lacprodan(Registered Trademark) PL‐20 is as follows: (Percentages(%) and minimum dosages per 16g) Shingomyelin 4.3% 688 mg Phosphatidyl choline (PC) 4.3% 688 mg Phosphatidyl serine (PS) 1.9% 304 mg Phosphatidyl ethanolamine (PE) 3.5% 560 mg Phosphatidyl inositol (PI) 1.3% 208 mg Gangliosides and others 0.7% 112 mg Treatment compliance will be monitored by the use of a compliance log which participants will take home with them and record the time at which they consume the drinks every day. If for some reason they miss a dose, they will be instructed to make a note of this in the log. In addition to the compliance log, participants will also be required to return all unused sachets at the completion of the study so that the experimenter can confirm that the number of sachets they have taken is in agreement with their log. CONDITION: Age‐associated Memory Impairment (AAMI) PRIMARY OUTCOME: Mini‐Mental State Examination (MMSE) ; ; The MMSE is brief test commonly used in assessment of cognitive impairment and dementia that takes approximately 5 to 10 minutes to complete. The test comprises of 11 questions used to measure orientation time and place, immediate recall, short term verbal memory, calculation, language and construct ability. A score out of 30 is calculated at the end of the test. ; Rey’s Verbal Learning Test (RVLT) ; ; The Prospective and Retrospective Memory Questionnaire (PRMQ) ; ; The PRMQ (Crawford, Smith, Maylor, Della Sala, & Logie, 2003) was developed in order to provide a self‐report measure of prospective and retrospective memory omissions in everyday life. The PRMQ consists of 16 items, with 8 items enquiring about prospective memory failures and 8 items enquiring about retrospective memory failures. Each item is scored on a 5‐part Likert scale from 1 (never) to 5 (very often). The total score range for the PRMQ is from 16 – 80, with higher scores indicating greater number of prospective and retrospective memory ommissions. An example of a retrospective item is: “do you fail to recognise a place you have visited before?” An example of a prospective item is: “do you fail to mention or give something to a visitor that you were asked to pass on?” ; SECONDARY OUTCOME: Biochemical Assessments ; ; Haematological testing will be conducted at training, baseline, 90 and 180 days. Blood samples will be used to measure HbA1c (glycated haemoglobin ‐ an index of blood glucose levels over the previous few weeks). Glucose control is well documented to decrease with age (Fink et al 1983), and this effect is suggested to contribute to age‐related cognitive decline (Messier et al 2003; Riby et al 2004). Therefore, we will measure glucoregulatory efficiency in our dataset of elderly individuals to ensure that differences in cognitive performance are not due to differences in glucoregulatory control. ; ; ; Improved HCy levels have been found to result from increased intake of phosphatidylcholine and choline. For these reasons serum choline will also be monitored throughout the study. ; The RVLT (Rey, 1958) is a test of verbal learning and memory that has a long history of use both in the assessment of clinical memory disturbances as well as cognitive decline associated with normal ageing (van der Elst, van Boxtel, van Breukelen, & Jolles, 2005). The RVLT consists of 15 monosyllabic words that are presented to participants in a fixed sequence at the rate of one word every two seconds. After the presentation of words participants are required to free‐recall as many words as they can. The encoding‐recall procedure is repeated five times. In the last trial a 20‐minute interval is imposed before participants repeat as many words as they can recall from the original list. The maximum and total number of correctly repeated words are recorded, together with the number of words recalled in the delayed‐recall condition (Rey, 1958). ; On the other assessment days (i.e. baseline, 90 and 180 days) blood samples will be taken in order to measure biochemical markers of oxidative stress (glutathione and F2 isoprostanes) and inflammation (cytokines TNF‐a, interleukins 1ß/6 and C‐reactive protein) together with blood levels of B‐Vitamins (B6,B9,B12) and homocysteine (HCy) levels. ; Cardiovascular measures ; ; Cardiovascular measures will be assessed using standard blood pressure assessment, SphygmoCor applanation tonometry, Transcranial Doppler as well as Flow Mediated Dilation. The SphygmoCor is a non‐invasive tool that measures aortic blood pressure and vascular elasticity (arterial stiffness). Transcranial Doppler, also a non‐invasive device, will be used to measure blood velocity in both the Middle Cerebral and Common Carotid arteries. Flow Mediated Dilation will be used to assess endothelial dependent vasodilation of the brachial artery. Such cardiovascular equipment adheres to the necessary Australian safety standards and is commonly used to assess and manage cardiovascular health. ; ; 1. Blood pressure ; Brachial blood pressure will be calculated with the participant seated and following a five minute rest period. Measurements will be calculated using a sphygmomanometer and an appropriately sized cuff. To ensure the accuracy of the assessment, blood pressure will be taken three times and averaged. ; ; 2. SphygmoCor ; Aortic blood pressure, pulse pressure and pulse wave velocity (all aspects of arterial stiffness and cardiovascular pressures) will be measured non‐invasively using the SphygmoCor. The researcher will place 3 recording electrode stickers on the participant’s chest in a lead II configuration. This will capture the participant’s heart rhythm. Using a pencil‐like sensor, the researchers will record the participants pulse allowing the SphygmoCor device to automatically derive all parameters of interest. ; ; 3. Transcranial Doppler ; This non‐invasive system will be used to record Middle Cerebral Artery (MCA) blood velocity by placing a sensor close to the participant’s ear whilst Common Carotid Artery (CCA) blood velocity will be recorded by gently placing a hand held sensor at the base of the participant’s neck. ; ; Hick's Reaction Time paradigm (Jensen box task) ; ; ; This will be identical to the serial threes task with the exception that it will involve serial subtraction of sevens. ; ; ; Rapid Visual Information Processing task (RVIP – 5 min): ; ; INCLUSION CRITERIA: ‐Male or female. ‐Aged >55 years. ; The Jensen box is an apparatus that distinguishes decision time and movement time from total reaction time. This apparatus has eight lights which are arranged in a semi‐circular configuration. A response button is located adjacent to each light. A "home" button is situated in the centre of the panel. Subjects are required to press the home button until they see a target light and then to release the home button as quickly as possible and to press the response button adjacent to the stimulus light. Decision time (DT) is defined as the time from stimulus onset to the release of the home button, and movement time (MT) as the time from release of the home button to the depression of the stimulus button. ; ; Choice is manipulated by varying the number of stimulus alternatives, from 0 (i.e. one light at one possible location) to multiple (i.e. the stimulus may appear in any one of the eight light positions). Participants will be given several practice trials in the eight stimulus (i.e. eight lights) condition so that they can familiarise themselves with the task. DTs of less than 150 ms are discarded as outliers, as it has been argued that physiological limits prevent shorter DTs (Jensen, 1987). DTs over 999 ms will also be discarded and replaced with an additional trial. In addition, all DTs exceeding three SDs above the subject's mean DT are also discarded (Jensen, 1987). The outcome measures are the median, mean and intra‐individual variability (*i ‐ average standard deviation) of both DT and MT for all choice, intercept of the DT function across choice and the slope of this function. ; Mood measures ; ; Beck Depression Inventory (BDI‐II) ; ; The Beck Depression Inventory (BDI‐II) is a 21‐item; self‐report inventory designed to measure the severity of depressive symptoms. The BDI‐II is one of the most widely used depression inventories in both clinical and research settings. The BDI‐II asks participants to rate how they have felt over the past 2 weeks on a scale of 0 (no symptoms) to 3 (severe symptoms). Higher scores on the BDI‐II indicates more severe depressive symptoms. The BDI‐II has adequate test‐retest reliability and high internal consistency. Furthermore, the BDI has been shown to be effective in measuring depressive symptoms in older populations (Gallagher, Nies, & Thompson, 1982). In the current study a cut off of 20 and higher will be used as evidence of severe depression. ; ; The Depression, Anxiety and Stress Scale (DASS) ; ; This short questionnaire has three sub‐factors: depression, anxiety and stress. The DASS is relevant for both clinical and non‐clinical populations and has adequate reliability and validity. The 21 items comprise affect related symptoms, pertaining to possible dysfunction or disorder, on a 4‐point scale from 0 to 3, thus yielding a possible range from 0 to 63. Higher scores indicate a higher degree of dysfunction and less desirable affect experience. A score of zero does not indicate positive mood, but rather the lack of presence of symptoms pertaining to dysphoric mood. Nevertheless the DASS is considered suitable for normal populations as some experience of such symptoms is considered normal in day‐to‐day life. ; ; Profile of Mood States (POMS) ; ; ; ; Bond‐Lader Visual Analogue Mood Scales ; Neuroimaging ; ; ; APOE Genotyping ; ; ; ; The following steps will be taken to manage this information: ; ; ; MTHFR Genotyping ; ; Swinburne University Computerized Cognitive Ageing Battery (SUCCAB) ; ; Spatial Working Memory ; Contextual Memory ; The Cognitive Demand Battery ; Serial threes subtraction task (2 min): ; ; ; Serial sevens subtraction task (2 min): ; The POMS (McNair, Lorr, & Droppleman, 1992) is a self‐report questionnaire designed to measure six dimensions of mood: tension‐anxiety; depression‐dejection; anger‐hostility; vigour‐activity; fatigue‐inertia; and confusion‐bewilderment. The POMS consists of 65 adjectives describing feeling and mood which is answered on a five‐point Likert‐type scale ranging from not at all to extremely. Respondents are asked to indicate mood reactions for the "past week including today". ; The Bond‐ Lader Visual Analogue Mood Scales (Bond & Lader, 1974) were originally designed for assessing the mood effects of anxiolytics and have been subsequently utilized in numerous pharmacological, psychopharmacological, and medical trials. As with other mood visual analogue scales, high reliability and validity have been demonstrated (Ahearn, 1997). The Bond and Lader scales comprise a total of 16 100‐mm lines anchored at either end by antonyms. Participants mark their current subjective state between the antonyms on the line. Each line is scored as millimeters to the mark from the negative antonym. From the resultant scores, three measures derived by factor analysis can be isolated. These have been described by Bond and Lader as representing the following: "alertness" (represented by lines anchored by alert–drowsy, attentive–dreamy, lethargic–energetic, muzzy–clearheaded, well‐coordinated–clumsy, mentally slow–quick witted, strong–feeble, interested–bored, incompetent–proficient); "calmness" (calm–excited, tense–relaxed); and "contentedness" (contented–discontented, troubled–tranquil, happy–sad, antagonistic–friendly, withdrawn–sociable). Scores for each factor represent the unweighted average number of millimeters (maximum 100 mm) from the negative antonym for the individual scales contributing to the factor. ; In a subset of 40 participants neuroimaging with functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) will be conducted in order to further explore the in vivo mechanisms of action of Lacprodan(Registered Trademark) PL‐20 in the brain. Previous neuroimaging studies using phosphatidylserine (PS) supplementation in AD have been conducted using electroencephalography (EEG) as well as positron emission tomography (PET). PET results revealed that for the PS group there was increased glucose metabolism during a visual recognition task across a number of brain regions, most notably the temperoparietal regions [120]. However, to‐date no further neuroimaging studies have been conducted using phospholipid interventions, and to the best of our knowledge none have been conducted using MRI or MEG. ; Blood samples obtained from haematological testing will also be used for the purpose of genetic assessment. Specifically, bloods will be analysed to determine the presence or absence of the APOE e4 allele as well as for polymorphisms in the MTHFR gene. Blood sampling for genetic analysis will be conducted once at the baseline study visit (V1). ; Genotyping for the APOE e4 allele will be used to investigate whether participants with and without the APOE e4 allele respond to the treatments differently and show differential relationships with the cognitive and biological variables. ; In the current study structural and functional MRI scans will be acquired using a Siemens 3 Telas tin trio MRI scanner, located at the Centre for Human Psychopharmacology, Swinburne University of Technology. During the initial scan, a structural image will be obtained for each participant and used as a reference point for further functional scans. Scanning for diffusion tensor imaging (DTI) analysis, a measure of white matter integrity, will also be conducted. Following DTI there will be scanning in a resting state in order to assess activity in the default mode network (DMN, approx. 6 minutes). Additional analysis of cell membrane fluidity will also be conducted by using the T2 signal timing information (relaxometry) while in a resting state. Changes in the blood oxygenation‐level dependent (BOLD) signal will also be analysed while participants complete in‐scanner versions of verbal episodic memory (approx. 20 minutes) and N‐Back working memory tasks (approx. 20 mintues). ; MEG scanning will be conducted using an Elekta Neuromag TRIUX MEG system, also located at the Centre for Human Psychopharmacology, Swinburne University of Technology. Initial scanning while in a resting state will be conducted in order to collect information as to activity in the default mode network (DMN). Following this scanning will be conducted whilst participants complete the same in‐scanner tasks as used in the fMRI task: verbal episodic memory and N‐Back working memory. The two tasks are kept the same across both fMRI and MEG in order for information from the two imaging modalities to be combined into a single comprehensive analysis. MEG scanning provides important complementary information which is additional to that provided by fMRI. The temporal resolution of MEG is far superior to fMRI; MEG is capable of recording neural oscillations from delta right through to the gamma range (>40Hz). Whilst the spatial resolution of MEG is less than that of fMRI, the high number of sensors (approx. 300) together with modern source reconstruction algorithms (e.g. beam forming) means that the spatial resolution of MEG is far superior to conventional scalp‐recorded EEG. The combination of the two imaging modalities is state‐of‐the‐art and will provide an unparalleled level of analysis regarding the effects of Lacprodan(Registered Trademark) PL‐20 on memory function. Pharmacogenetic measures ; The results of the APOE testing may indicate an individual is at a higher risk of developing late onset Alzheimer’s disease. However, it is not possible to determine whether an individual will eventually develop Alzheimer’s disease based on the presence of the APOE e4 allele. ; Information about the APOE testing will be included in the Form of Disclosure. Participants will also be provided with an Alzheimer’s Disease Genetic fact sheet (see attached) to read prior to signing the consent form. The researchers will not disclose the results of the APOE testing to the participants. Release of genetic data will be done in consultation with the participants GP. ; In the situation that a participant requests access to their results, the release of genetic data will be done in consultation with the participants GP. The GP will be provided with the Alzheimer’s Disease Genetic fact sheet and some information regarding the APOE status test in relation to the research project to read prior to consultation with the participant. The GP will also be provided with the contact details of a qualified genetic counselor to refer participants to make an appointment to discuss their results if they experience any further concerns about the meaning of these results. ; The methyltetrahydrofolate reductase (MTHFR) gene has been found to influence the way in which B‐Vitamins are metabolised, as well as the accumulation of Homocysteine. Genotyping for the MTHFR gene will be used to investigate whether polymorphisms in the MTHFR gene influence the effects of Lacprodan(Registered Trademark) PL‐20 on cognition and mood. MTHFR status has not been found to be a risk factor for dementia, although it may indicate the extent to which homocysteine is accumulated in the body. ; The SUCCAB is a computerized test battery of tasks designed to capture a range of cognitive functions that decline with age. In the current study two tasks from the SUCCAB test battery will be used: Contextual Memory and Spatial Working Memory. ; In each trial participants are presented with a 4x4 white grid on a black background, with six grid positions containing white squares. Participants are given 3 seconds to remember where the white squares are located. The grid became blank and a series of four white squares were sequentially displayed in various grid positions for 2‐seconds each. Participants responded with a yes/no response to indicate whether each square matched a position that was originally filled. In total, participants complete 14 trials, each of which are separated by a blank screen displayed for 2‐seconds. Each trial was set such that two out of the four locations in the response series corresponded to the original grid locations, and two did not. The task requires participants to hold spatial information in working memory. ; A series of 20 everyday images are presented at the top/bottom/left/right of the screen for 3‐seconds each with no ISI. On completion of the series the same images are displayed again in randomized order in the centre of the screen for 2‐seconds each with no ISI. Participants respond with a top/bottom/left/right button press to indicate the original location of each image. The task requires participants to recall the spatial context of the original presentation and was used as a measure of episodic memory. ; The objective of these tasks is to assess the impact of treatment on continuous cognitive demand. The overall cognitive load in the session increases as participants complete these tests repeatedly for a period of approximately 30‐minutes. These tasks assess the interaction between a given intervention and 'mental demand'. The Cognitive Demand Battery comprised of two computerised serial subtraction tasks (Serial Threes and Serial Sevens) the Bakan Rapid Visual Information Processing task (RVIP) and a paper‐and‐pencil measure of mental fatigue. ; Participants will be required to count backwards in threes from a given number as quickly and as accurately as possible using the computer keyboard number keys to enter each response. A random starting number between 800 and 999 will be presented on the computer screen, which will then be cleared by the entry of the first response. The task will be scored for number of correct responses and number of errors. ; The participant will be required to monitor a continuous series of digits for targets of three consecutive odd or three consecutive even digits. The digits will be presented at the rate of 100 per minute and the participant will be required to responded to the detection of a target string by pressing the ‘space bar’ as quickly as possible. The task will be continuous and last for 5 minutes, with 8 correct target strings being presented in each minute. RVIP will be scored for percentage of target strings correctly detected, average reaction time for correct detections, and number of false alarms. ‐Meets diagnostic criteria for age‐associated memory impairment: AAMI is defined on the basis of criteria first outlined by Crook et al: (i) A score >25 on the Memory Complaint Questionnaire (MAC‐Q) and (ii) a score at =1 standard deviation below the mean for healthy young adults on the Paired Associates Test from the Wechsler Memory Scale ‐ Revised (WMS‐R) ‐Willing and able to provide written informed consent. ‐Understands and is willing and able to comply with all study procedures. ‐English speaking. ‐Normal or corrected vision. ‐Must be right‐handed (applies only to the neuroimaging sub‐study).