Effect of Treatment of the Cholinergic Precursor Choline Alphoscerate in Mild Cognitive Dysfunction: A Randomized Controlled Trial.

Background and Objectives: The focus on mild cognitive dysfunction in adults is of great interest, given the risk of worsening and conversion to dementia. Cognitive dysfunctions are characterized by a decrease in the weight and volume of the brain, due to cortical atrophy, with a widening of the grooves and flattening of the convolutions. Brain atrophy that mainly involves the hippocampus is related to the progression of cognitive impairment and the conversion from mild cognitive dysfunction to dementia. Currently, there is no treatment for MCI. Results from a trial on Alzheimer's disease (ASCOMALVA trial) suggest that a sustained cholinergic challenge can slow the progression of brain atrophy typical of Alzheimer's disease associated with vascular damage. This study intends to evaluate the efficacy of choline alphoscerate in patients with mild cognitive impairment (MCI) and associated vascular damage, in stabilizing and/or slowing brain atrophy typical of adult-onset cognitive dysfunction, and in improving and/or slowing the progression of cognitive and behavioral symptoms associated with MCI. Materials and Methods: This randomized controlled trial will recruit 60 patients that will be evaluated and randomized in a 1:1 ratio to receive choline alphoscerate (1200 mg/day) or placebo, for 12 months. Analyses will be carried out using SPSS vesion No 26 the Statistician in charge of this study, with the statistical significance level chosen as 0.05. Discussion: This trial may provide evidence about the efficacy of treatment with the cholinergic precursor choline alphoscerate in patients with mild cognitive dysfunction. The results of this study will be published in peer-reviewed journals. Registration: EudraCT number: 2020-000576-38.

Pharmacological enhancement of cholinergic neurotransmission alleviates neuroinflammation and improves functional outcomes in a triple transgenic mouse model of Alzheimer's disease.

Introduction: Alzheimer's disease (AD) is the most common neurodegenerative disorder affecting the elderly population worldwide. Due to the multifactorial nature of the disease, involving impairment of cholinergic neurotransmission and immune system, previous attempts to find effective treatments have faced challenges. Methods: In such scenario, we attempted to investigate the effects of alpha-glyceryl-phosphoryl-choline (α-GPC), a cholinomimetic molecule, on neuroinflammation and memory outcome in the triple transgenic mouse model of AD (3xTg-AD). Mice were enrolled at 4 months of age, treated orally with α-GPC dissolved in drinking water at a concentration resulting in an average daily dose of 100 mg/kg for 8 months and sacrificed at 12 months of age. Thereafter, inflammatory markers, as well as cognitive parameters, were measured. Results: Chronic α-GPC treatment reduced accumulation of amyloid deposits and led to a substantial re-balance of the inflammatory response of resident innate immune cells, astrocytes and microglia. Specifically, fluorescent immunohistochemistry and Western blot analysis showed that α-GPC contributed to reduction of cortical and hippocampal reactive astrocytes and pro-inflammatory microglia, concurrently increasing the expression of anti-inflammatory molecules. Whereas α-GPC beneficially affect the synaptic marker synaptophysin in the hippocampus. Furthermore, we observed that α-GPC was effective in restoring cognitive dysfunction, as measured by the Novel Object Recognition test, wherein 3xTg-AD mice treated with α-GPC significantly spent more time exploring the novel object compared to 3xTg-AD untreated mice. Discussion: In conclusion, chronic treatment with α-GPC exhibited a significant anti-inflammatory activity and sustained the key function of hippocampal synapses, crucial for the maintenance of a regular cognitive status. In light of our results, we suggest that α-GPC could be exploited as a promising therapeutic approach in early phases of AD.

Choline-Containing Phospholipids in Stroke Treatment: A Systematic Review and Meta-Analysis.

BACKGROUND: Globally, stroke is the second leading cause of death and disability. In different studies conducted previously, the choline-containing phospholipids citicoline and choline alphoscerate have been proposed as adjuvants in the treatment of acute strokes. A systematic review was conducted to provide updated information on the effects of citicoline and choline alphoscerate in patients with acute and hemorrhagic strokes. METHODS: PubMed/Medline, Scopus, and Web of Science were searched to identify relevant materials. Data were pooled, and odds ratios (OR) were reported for binary outcomes. Using mean differences (MD), we evaluated continuous outcomes. RESULTS: A total of 1460 studies were reviewed; 15 studies with 8357 subjects met the eligibility criteria and were included in the analysis. In our study, citicoline treatment did not result in improved neurological function (NIHSS < 1, OR = 1.05; 95% confidence interval (CI): 0.87-1.27) or functional recovery (mRS < 1, OR = 1.36; 95% CI: 0.99-1.87) in patients with acute stroke. Choline alphoscerate improved neurological function and functional recovery in stroke patients based on the Mathew's scale and the Mini-Mental State Examination (MMSE). CONCLUSION: Citicoline did not improve the neurological or functional outcomes in acute stroke patients. In contrast, choline alphoscerate improved neurological function and functional recovery and reduced dependency in stroke patients.

Activity of Choline Alphoscerate on Adult-Onset Cognitive Dysfunctions: A Systematic Review and Meta-Analysis.

BACKGROUND: Choline alphoscerate (alpha glyceryl phosphorylcholine, α-GPC) is a choline-containing phospholipid used as a medicine or nutraceutical to improve cognitive function impairment occurring in neurological conditions including adult-onset dementia disorders. Despite its 1985 marketing authorization, there are still discrepancies between countries regarding its approval as a prescription medicine and discussions about its effectiveness. OBJECTIVE: This study aimed to evaluate the efficacy of the α-GPC compound for treating cognitive impairment in patients with adult-onset neurological disorders. METHODS: Relevant studies were identified by searching PubMed, Web of Science, and Embase. Studies that evaluated the effects of α-GPC alone or in combination with other compounds on adult-onset cognitive impairment reporting cognition, function, and behavior were considered. We assessed the risk of bias of selected studies using the Cochrane risk of bias tool. RESULTS: A total of 1,326 studies and 300 full-text articles were screened. We included seven randomized controlled trials (RCTs) and one prospective cohort study that met our eligibility criteria. We found significant effects of α-GPC in combination with donepezil on cognition [4 RCTs, mean difference (MD):1.72, 95% confidence interval (CI): 0.20 to 3.25], functional outcomes [3 RCTs, MD:0.79, 95% CI: 0.34 to 1.23], and behavioral outcomes [4 RCTs; MD: -7.61, 95% CI: -10.31 to -4.91]. We also observed that patients who received α-GPC had significantly better cognition than those who received either placebo or other medications [MD: 3.50, 95% CI: 0.36 to 6.63]. CONCLUSION: α-GPC alone or in combination with donepezil improved cognition, behavior, and functional outcomes among patients with neurological conditions associated with cerebrovascular injury.

Effects of choline containing phospholipids on the neurovascular unit: A review.

The roles of choline and of choline-containing phospholipids (CCPLs) on the maintenance and progress of neurovascular unit (NVU) integrity are analyzed. NVU is composed of neurons, glial and vascular cells ensuring the correct homeostasis of the blood-brain barrier (BBB) and indirectly the function of the central nervous system. The CCPLs phosphatidylcholine (lecithin), cytidine 5'-diphosphocholine (CDP-choline), choline alphoscerate or α-glyceryl-phosphorylcholine (α-GPC) contribute to the modulation of the physiology of the NVU cells. A loss of CCPLs contributes to the development of neurodegenerative diseases such as Alzheimer's disease, multiple sclerosis, Parkinson's disease. Our study has characterized the cellular components of the NVU and has reviewed the effect of lecithin, of CDP-choline and α-GPC documented in preclinical studies and in limited clinical trials on these compounds. The interesting results obtained with some CCPLs, in particular with α-GPC, probably would justify reconsideration of the most promising molecules in larger attentively controlled studies. This can also contribute to better define the role of the NVU in the pathophysiology of brain disorders characterized by vascular impairment.

Effect of Choline Alphoscerate on the Survival of Glioblastoma Patients: A Retrospective, Single-Center Study.

Cognitive impairment often occurs in glioblastoma (GBM) patients due to the tumor itself and treatment side effects. Choline alphoscerate (L-alpha-glycerylphosphorylcholine, GPC) is frequently used to compensate for cognitive impairment in GBM patients. This study was conducted to determine whether GPC affects the overall survival (OS) and progression-free survival (PFS) of GBM patients. From 2011 to 2020, 187 isocitrate dehydrongenase (IDH)-wild-type GBM patients were analyzed. The patients were classified based on whether GPC was continuously used for at least 3 or 12 months (mos) after GBM diagnosis. Although GPC usage (≥3 mos) did not make significant differences in survival extension, median OS in the long-term GPC group (≥12 mos) was longer with statistical significance, compared to the control group (<12 mos) (38.3 vs. 24.0 mos, p = 0.004). In addition to younger age, supratentorial location, complete resection, and MGMT promoter methylation, long-term use of GPC (≥12 mos) was significantly associated with longer OS in multivariate analysis (p = 0.019, hazard ratio [HR] 0.532, 95% confidence interval [CI] 0.314−0.900). Despite the limitations of this study, long-term GPC use was possibly associated with prolonged survival in GBM patients. Multi-center prospective randomized studies with a large number of patients are needed to validate these findings.

Association Between the Cholinesterase Inhibitor Donepezil and the Cholinergic Precursor Choline Alphoscerate in the Treatment of Depression in Patients with Alzheimer's Disease.

Background: Depressive symptoms are common in Alzheimer's disease (AD) patients and are associated with an increased functional decline. Selective serotonin reuptake inhibitor antidepressants showed a limited efficacy. Objective: The purpose of this work was to evaluate if a higher brain cholinergic stimulation induced by the association between the acetylcholinesterase inhibitor donepezil and the cholinergic precursor choline alphoscerate has any effect on depression in AD patients. Methods: Patients were selected among those recruited in the ASCOMALVA (association between the cholinesterase inhibitor donepezil and the cholinergic precursor choline alphoscerate in AD) trial. Depressive symptoms were investigated in 90 AD patients through the neuropsychiatric inventory at baseline and after 3, 6, 9, 12, 18, and 24 months of treatment. Patients were randomized in a group association therapy (45 subjects) receiving donepezil 10 mg plus choline alphoscerate 1,200 mg/day, and a group monotherapy (45 subjects) receiving donepezil 10 mg/day plus placebo. Based on the results of the MMSE at the recruitment patients were divided into 3 groups: severely impaired (score < 15); moderately impaired (score 19-16); mild-moderately impaired (score 24-20). Results: Depression symptoms were significantly lower (p < 0.05) in patients treated with donepezil plus choline alphoscerate compared to patients treated with donepezil alone. Subjects of the group having mild to moderate cognitive impairment were those more sensitive to the association treatment. Conclusion: Depression symptoms of AD patients in the mild to moderate stage probably could to benefit of a stronger cholinergic stimulation induced by associating donepezil with the cholinergic precursor choline alphoscerate.

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.

The effect of choline alphoscerate on non spatial memory and neuronal differentiation in a rat model of dual stress.

Choline alphoscerate (α-GPC) is a choline-based compound and acetylcholine precursor commonly found in the brain; it has been known to be effective in treating neuronal injury and increasing the levels of acetylcholine (Ach) and brain-derived neurotrophic factor (BDNF) which in turn enhances memory and cognitive function. This study was designed to establish rat models of dual stress using noise and restraint in order to investigate the effect of α-GPC on cognitive function and neuronal differentiation after dual stress. The rats were randomly divided into four groups as follows: a control group (CG), a control with α-GPC group (CDG), a noise-restraint stress group (NRSG), and a noise-restraint stress with α-GPC group (NRSDG). Experimental groups were exposed to a 110 dB sound pressure level (SPL) white band noise and restraint at the same time for 3 h/day for 7 days. Alpha-GPC (400 mg/kg) was administered orally after stress exposure for 7 days. NRSG showed decreased memory function, increased stress hormone, hearing loss, and neuronal damage of the brain. In the hippocampus of NRSG, significantly increased expression of IL-1ß and decreased expression of both choline acetyltransferase (ChAT) and BDNF were observed. On the contrary, NRSDG showed better memory function compared to NRSG, which indicates the neuroprotective effect of α-GPC. In addition, NRSDG showed decreased immune response and increased ChAT and BDNF expression as well as neuroblast expression in the hippocampus, which suggests that α-GPC enhances BDNF expression and protects the activity of immature cells in the hippocampus. To the best of our knowledge, this is the first study to show the protective effect of α-GPC on cognitive dysfunction by promotion of neuronal differentiation in an animal model of stress.

Volume Analysis of Brain Cognitive Areas in Alzheimer's Disease: Interim 3-Year Results from the ASCOMALVA Trial.

BACKGROUND: Cerebral atrophy is a common feature of several neurodegenerative disorders, including Alzheimer's disease (AD). In AD, brain atrophy is associated with loss of gyri and sulci in the temporal and parietal lobes, and in parts of the frontal cortex and cingulate gyrus. OBJECTIVE: The ASCOMALVA trial has assessed, in addition to neuropsychological analysis, whether the addition of the cholinergic precursor choline alphoscerate to treatment with donepezil has an effect on brain volume loss in patients affected by AD associated with cerebrovascular injury. METHODS: 56 participants to the randomized, placebo-controlled, double-blind ASCOMALVA trial were assigned to donepezil + placebo (D + P) or donepezil + choline alphoscerate (D + CA) treatments and underwent brain magnetic resonance imaging and neuropsychological tests every year for 4 years. An interim analysis of 3-year MRI data was performed by voxel morphometry techniques. RESULTS: The D + P group (n = 27) developed atrophy of the gray and white matter with concomitant increase in ventricular space volume. In the D + CA group (n = 29) the gray matter atrophy was less pronounced compared to the D + P group in frontal and temporal lobes, hippocampus, and amygdala. These morphological data are consistent with the results of the neuropsychological tests. CONCLUSION: Our findings indicate that the addition of choline alphoscerate to standard treatment with the cholinesterase inhibitor donepezil counters to some extent the loss in volume occurring in some brain areas of AD patients. The observation of parallel less pronounced decrease in cognitive and functional tests in patients with the same treatment suggests that the morphological changes observed may have functional relevance.

Association of nimodipine and choline alphoscerate in the treatment of cognitive impairment in patients with cerebral small vessel disease: study protocol for a randomized placebo-controlled trial-the CONIVaD trial.

BACKGROUND: Vascular cognitive impairment (VCI) is an extremely disabling condition that includes post-stroke dementia and VCI caused by cerebral small vessel disease (SVD). Currently, there is no approved treatment for this condition. Drugs active on the cholinergic pathway have been tested in VCI patients showing positive but limited efficacy. The calcium-antagonist nimodipine also showed some moderate positive effects in VCI patients. AIMS: CONIVaD (choline alphoscerate and nimodipine in vascular dementia) is a pilot, single-center, double-blinded, randomized trial aimed to assess whether the association of choline alphoscerate and nimodipine is more effective than nimodipine alone in reducing cognitive decline in patients with SVD and mild-to-moderate cognitive impairment. METHODS: All patients are evaluated at baseline and after 12 months with: (1) clinical, daily functions, quality of life, and mood assessment and (2) extensive neuropsychological evaluation. After the baseline evaluation, patients are randomly assigned to one of the two arms of treatment: (1) nimodipine 90 mg/die t.i.d plus placebo b.i.d and (2) nimodipine 90 mg t.i.d plus choline alphoscerate 1200 mg/die b.i.d. for a total of 12 months. The primary endpoint is cognitive decline, expressed as the loss of at least two points on the Montreal Cognitive Assessment at 12 months. Secondary endpoints include safety and tolerability, functional, quality of life, and neuropsychological measures. DISCUSSION: CONIVaD study is the first randomized controlled trial to examine the cognitive efficacy of combined choline alphoscerate-nimodipine treatment in VCI patients. Results of this pilot study will serve as a methodological basis for other clinical controlled, multicentric, double-blinded, and randomized trials. TRIAL REGISTRATION: Clinical Trial NCT03228498. Registered 25 July 2017.

[Clinical efficacy and safety of choline alfoscerate in the treatment of late-onset cognitive impairment]. / Klinicheskaia éffektivnost' i bezopasnost' primeneniia kholina al'fostserata v lechenii dodementnykh kognitivnykh narushenii v pozdnem vozraste.

AIM: To study the efficacy and safety of cereton (choline alfoscerate) in the treatment of elderly patients with amnestic type of mild cognitive impairment (aMCI), which often represents a pre-dementia (symptomatic) stage of Alzheimer's disease (AD). MATERIAL AND METHODS: Fifty patients (40 women and 10 men; mean age 68,8 years) received three-month therapy with cereton in a dose of 1200 mg/day in 3 divided doses. Fifteen patients received the same treatment again within 1 year. Immediate and delayed (7-9 months after treatment) effects of therapy, including those dependent on the ApoE genotype were assessed with a neuropsychological test battery. RESULTS: Psychometric measures showed a significant improvement after treatment with cereton. ApoE4 allele noncarriers performed better on tests of immediate and delayed reproduction of 10 words. Although, most indicators achieved in the end of therapy course decreased 7-9 months after treatment, the level of patients cognitive functioning remained at a higher level than before treatment. A repeated course of cereton treatment prevents cognitive deficit increasing during the follow-up period (10-12 months). CONCLUSION: The drug is well-tolerated and safe and can be recommended for preventive treatment of dementia in patients with high AD risk, in particular in elderly patients with aMCI syndrome.

Choline and Choline alphoscerate Do Not Modulate Inflammatory Processes in the Rat Brain.

Choline is involved in relevant neurochemical processes. In particular, it is the precursor and metabolite of acetylcholine (ACh). Choline is an essential component of different membrane phospholipids that are involved in intraneuronal signal transduction. On the other hand, cholinergic precursors are involved in ACh release and carry out a neuroprotective effect based on an anti-inflammatory action. Based on these findings, the present study was designed to evaluate the effects of choline and choline precursor (Choline alphoscerate, GPC) in the modulation of inflammatory processes in the rat brain. Male Wistar rats were intraperitoneally treated with 87 mg of choline chloride/kg/day (65 mg/kg/day of choline), and at choline-equivalent doses of GPC (150 mg/kg/day) and vehicle for two weeks. The brains were dissected and used for immunochemical and immunohistochemical analysis. Inflammatory cytokines (Interleukin-1ß, IL-1ß; Interleukin-6 , IL-6 and Tumor Necrosis Factor-α, TNF-α) and endothelial adhesion molecules (Intercellular Adhesion Molecule, ICAM-1 and Vascular cell Adhesion Molecule, VCAM-1) were studied in the frontal cortex, hippocampus, and cerebellum. The results clearly demonstrated that treatment with choline or GPC did not affect the expression of the inflammatory markers in the different cerebral areas evaluated. Therefore, choline and GPC did not stimulate the inflammatory processes that we assessed in this study.

The Effect of the Association between Donepezil and Choline Alphoscerate on Behavioral Disturbances in Alzheimer's Disease: Interim Results of the ASCOMALVA Trial.

BACKGROUND: Behavioral and psychological symptoms of dementia (BPSD) are a group of psychological reactions, psychiatric symptoms, and behaviors commonly found in Alzheimer's disease (AD). Four clusters of BPSD have been described: mood disorders (depression, anxiety, and apathy), psychotic symptoms (delusions and hallucinations), aberrant motor behaviors (pacing, wandering, and other purposeless behaviors), and inappropriate behaviors (agitation, disinhibition, and euphoria). Most of them are attributed to acetylcholine deficiency. OBJECTIVE: To evaluate if a higher amount of acetylcholine obtained by associating donepezil and choline alphoscerate might have a favorable effect on BPSD. METHODS: BPSD were measured at baseline and after 24 months in 113 mild/moderate AD patients, included in the double-blind randomized trial ASCOMALVA, by the Neuropsychiatric Inventory (NPI). Two matched groups were compared: group A treated with donepezil (10 mg/day) plus choline alphoscerate (1200 mg/day), and group B treated with donepezil (10 mg/day) plus placebo. RESULTS: Data of NPI revealed a significant decrease of BPSD severity and distress of the caregiver in patients of group A compared with group B. Mood disorders (depression, anxiety and apathy) were significantly decreased in subjects treated with donepezil and choline alphoscerate, while their severity and frequency was increased in the other group. CONCLUSIONS: Patients treated with donepezil plus choline alphoscerate showed a lower level of behavioral disturbances than subjects treated with donepezil only, suggesting that the association can have beneficial effects.

Apathy Treatment in Alzheimer's Disease: Interim Results of the ASCOMALVA Trial.

BACKGROUND: Apathy is a common symptom in Alzheimer's disease (AD), but no treatment has proven to be effective, although administration of cholinesterase inhibitors has been associated with moderate improvements in the short term. OBJECTIVE: This study has compared apathy scores of patients included in "ASCOMALVA" trial treated for two years with donepezil plus a cholinergic precursor (choline alphoscerate), to those of patients receiving donepezil alone with the purpose of assessing if the availability of a higher amount of acetylcholine by combining precursor loading and inhibition of neurotransmitter breakdown would counter apathy in AD. METHODS: Apathy was measured at baseline and 3, 6, 9, 12, 18, and 24 months using the apathy subtest of the Neuropsychiatric Inventory in 113 mild-moderate AD patients. Two matched groups were compared: group 1 (56 subjects) treated with donepezil plus choline alphoscerate and group 2 (57 subjects) treated with donepezil alone. Frontal functions were explored by the Frontal Assessment Battery (FAB) at baseline. RESULTS: Group 1 subjects showed, as a whole, a lower apathy score after 12 to 24 months. The caregiver distress was descreased after 6 to 24 months. Results were unrelated with cognitive scores measured by the MMSE and ADAS-cog test. Subjects with FAB in the normal range had significantly lower scores. CONCLUSIONS: The combination of donepezil with choline alphoscerate is more effective than donepezil alone in countering symptoms of apathy in AD. This suggests that the availability in brain of a higher amount of acetylcholine could affect apathy in AD subjects with spared executive functions.

The ASCOMALVA (Association between the Cholinesterase Inhibitor Donepezil and the Cholinergic Precursor Choline Alphoscerate in Alzheimer's Disease) Trial: interim results after two years of treatment.

Cholinesterase inhibitors (ChE-Is) are used for symptomatic treatment of mild-to-moderate Alzheimer's disease (AD), but long-term effects of these compounds are mild and not always obvious. Preclinical studies have shown that combination of ChE-Is and the cholinergic precursor choline alphoscerate increases brain acetylcholine levels more effectively than single compounds alone. ASCOMALVA (Effect of association between a ChE-I and choline alphoscerate on cognitive deficits in AD associated with cerebrovascular injury) is a double-blind trial investigating if the ChE-I donepezil and choline alphoscerate in combination are more effective that donepezil alone. The trial has recruited AD patients suffering from ischemic brain damage documented by neuroimaging and has completed 2 years of observation in 113 patients of the 210 planned. Patients were randomly allotted to an active treatment group (donepezil + choline alphoscerate) or to a reference group (donepezil + placebo). Cognitive functions were assessed by the Mini-Mental State Evaluation and Alzheimer's Disease Assessment Scale Cognitive subscale. Daily activity was evaluated by the basic and instrumental activities of daily living tests. Behavioral symptoms were assessed by the Neuropsychiatric Inventory. Over the 24-month observation period, patients of the reference group showed a moderate time-dependent worsening in all the parameters investigated. Treatment with donepezil plus choline alphoscerate significantly slowed changes of the different items analyzed. These findings suggest that the combination of choline alphoscerate with a ChE-I may prolong/increase the effectiveness of cholinergic therapies in AD with concomitant ischemic cerebrovascular injury.