Two of the most prevalent neurodegenerative disorders (NDDs), Alzheimer’s disease (AD) and Parkinson’s disease (PD), present significant challenges to healthcare systems worldwide. While the etiologies of AD and PD differ, both diseases share commonalities in synaptic dysfunction, thereby focusing attention on the role of neurotransmitters. The possible functions that platelets may play in neurodegenerative illnesses including PD and AD are becoming more acknowledged. In AD, platelets have been investigated for their ability to generate amyloid-ß (Aß) peptides, contributing to the formation of neurotoxic plaques. Moreover, platelets are considered biomarkers for early AD diagnosis. In PD, platelets have been studied for their involvement in oxidative stress and mitochondrial dysfunction, which are key factors in the disease’s pathogenesis. Emerging research shows that platelets, which release glutamate upon activation, also play a role in these disorders. Decreased glutamate uptake in platelets has been observed in Alzheimer’s and Parkinson’s patients, pointing to a systemic dysfunction in glutamate handling. This paper aims to elucidate the critical role that glutamate receptors play in the pathophysiology of both AD and PD. Utilizing data from clinical trials, animal models, and cellular studies, we reviewed how glutamate receptors dysfunction contributes to neurodegenerative (ND) processes such as excitotoxicity, synaptic loss, and cognitive impairment. The paper also reviews all current medications including glutamate receptor antagonists for AD and PD, highlighting their mode of action and limitations. A deeper understanding of glutamate receptor involvement including its systemic regulation by platelets could open new avenues for more effective treatments, potentially slowing disease progression and improving patient outcomes.

Increasing stroke burden in India demands a long-term stroke surveillance framework. Earlier studies in India were urban-based, short term and provided limited data on stroke incidence and its outcomes. This gap is addressed by the establishment of five population-based stroke registries (PBSRs) of the National Stroke Registry Programme, India. This paper describes stroke incidence, mortality and age, sex, and subtypes distribution in the five PBSRs with urban and rural populations. First-ever incident stroke patients in age group ≥18 years, resident for at least one year in the defined geographic area, identified from health facilities were registered. Death records with stroke as the cause of death from the Civil Registration System (CRS) were included. Transient ischemic attack (TIA) was excluded. Three PBSRs (Cuttack, Tirunelveli, Cachar) included urban and rural populations. PBSRs in Kota and Varanasi were urban areas. The crude and age-standardized incidence rate (ASR) by age, sex, and residence (urban and rural), rate ratios of ASR, case fatality proportions and rates at day 28 after onset of stroke were calculated for years 2018-2019. A total of 13,820 registered first-ever stroke cases that included 985 death certificate-only cases (DCOs) were analysed. The pooled crude incidence rate was 138.1 per 100,000 population with an age-standardized incidence rate (ASR) of 103.4 (both sexes), 125.7 (males) and 80.8 (females). The risk of stroke among rural residents was one in seven (Cuttack), one in nine (Tirunelveli), and one in 15 (Cachar). Ischemic stroke was the most common type in all PBSRs. Age-standardized case fatality rates (ASCFR) per 100,000 population for pooled PBSRs was 30.0 (males) and 18.8 (females), and the rate ratio (M/F) ranged from 1.2 (Cuttack) to 2.0 (Cachar). Population-based registries have provided a comprehensive stroke surveillance platform to measure stroke burden and outcomes by age, sex, residence and subtype across India. The rural-urban pattern of stroke incidence and mortality shall guide health policy and programme planning to strengthen stroke prevention and treatment measures in India. The National Stroke Registry Programme is funded through the intramural funding of the Indian Council of Medical Research, Department of Health Research, Ministry of Health and Family Welfare, India.

Objectives Poststroke cognitive decline (PSCD) is a serious disabling consequence of stroke. The purpose of this study is to find the prevalence of PSCD and sociodemographic and clinical determinants of risk factors of PSCD. Materials and Methods This study was a prospective, hospital-based study conducted on 200 stroke patients from stroke registry during October 2015 to April 2017. Detailed clinical evaluation was done. Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) scores were used to determine PSCD after 3 and 6 months as per the Diagnostic and Statistical Manual of Mental Disorders V. Chi-squared test was used to find the association between two variables. The Wilcoxon signed-rank test was used to compare the difference in cognitive impairment between two follow-ups at 3 and 6 months, respectively. A p-value < 0.05 was considered statistically significant. Results The prevalence of PSCD measured by MoCA scale at 3 and 6 months was 67 and 31.6%, respectively. By MMSE scale, cognitive decline prevalence at 3 months was found to be 87 (46.3%), which reduced to 22 (17.1%) at 6 months. The association between MMSE scale and type of stroke was significant at 3 months. Conclusion One-third of the stroke patients developed PSCD within 3 months of onset of stroke, with different levels of severity. The major predictors of new-onset poststroke cognitive impairment were diabetes and hypertension. The prevalence of PSCD reduced significantly at 6 months of stroke on follow-up.

Platelets are highly sensitive blood cells, which play central role in hemostasis and thrombosis. Platelet dense granules carry considerable amount of neurotransmitter glutamate that is exocytosed upon cell activation. As platelets also express glutamate receptors on their surface, it is pertinent to ask whether exposure to glutamate would affect their signalling within a growing thrombus. In this study we demonstrate that, glutamate per se induced synthesis of thrombogenic peptides, plasminogen activator inhibitor-1 and hypoxia-inducible factor-2α, from pre-existing mRNAs in enucleate platelets, stimulated cytosolic calcium entry, upregulated RhoA-ROCK-myosin light chain/myosin light chain phosphatase axis, and elicited extensive shedding of extracellular vesicles from platelets. Glutamate, too, incited platelet spreading and adhesion on to immobilized matrix under arterial shear, raised mitochondrial transmembrane potential associated with generation of reactive oxygen species and induced activation of AMP-activated protein kinase in platelets. Taken together, glutamate switches human platelets to pro-activation phenotype mediated mostly through AMPA receptors and thus targeting glutamate receptors may be a promising anti-platelet strategy.