China
Africa
Explore chapters and articles related to this topic
Neurology
Published in Kaji Sritharan, Jonathan Rohrer, Alexandra C Rankin, Sachi Sivananthan, Essential Notes for Medical and Surgical Finals, 2021
Kaji Sritharan, Jonathan Rohrer, Alexandra C Rankin, Sachi Sivananthan
Initial symptoms are usually that of memory impairment, which is epi sodic (‘forgetting events’) and/or topographical (‘getting lost’). ApoE4 is a risk factor. Biochemically, acetylcholine is deficient. On MRI, there is typically bilateral hippocampal atrophy. As the disease progresses, global cognitive impairment and global atrophy are seen. Amyloid plaques and tau-positive neurofibrillary tangles are present on post-mortem. Treatment: cholinesterase inhibitors (donepezil, rivastigmine, galan ta mine) do not affect the underlying disease, but roughly about ¹⁄³ of patients will remain at the same (or slightly higher) level of function for 1–2 years.
Degenerative Diseases of the Nervous System
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
James A. Mastrianni, Elizabeth A. Harris
Cholinesterase inhibitors may be effective for cognitive, neuropsychiatric, and motor symptoms. Rivastigmine has been shown to improve attention and hallucinations, delusions, and anxiety.31 Donepezil has been shown to improve cognition as well.32 Patients initiating cholinesterase inhibitors should be monitored for GI distress, weight loss, and other adverse effects. Drugs with anticholinergic properties should be avoided. Memantine has also been tried in the treatment of DLB, however, data are conflicting.
Heterocyclic Drug Design and Development
Published in Rohit Dutt, Anil K. Sharma, Raj K. Keservani, Vandana Garg, Promising Drug Molecules of Natural Origin, 2020
Garima Verma, Mohammad Shaquiquzzaman, Mohammad Mumtaz Alam
Acetylcholinesterase agents are those which prevent the breakdown of acetylcholine, a neurotransmitter. These inhibitors inhibit the enzyme cholinesterase which is actually responsible for the lysis of acetylcholine. They are used for the treatment of dementia encountered in the patients suffering from Alzheimer’s disease (Ogbru, 2017). Some frequently used cholinesterase inhibitors are tacrine, donepezil, galantamine, rivastigmine, and memantine. Inhibitors obtained from plants are given in Table 9.14.
Neuroprotective properties of solanum leaves in transgenic Drosophila melanogaster model of Alzheimer's disease
Published in Biomarkers, 2022
Opeyemi B. Ogunsuyi, Tosin A. Olasehinde, Ganiyu Oboh
Oxidative stress is considered a risk factor for the onset of AD (Cosín-Tomàs et al. 2019). Studies have shown that in AD patients, the brain is marked by oxidative stress associated with accumulation of Aβ and the deposition of neurofibrillary tangles (Christen 2000, Huang et al. 2016). Antioxidant therapy has also been globally accepted as therapeutic intervention for AD. Due to the established link between oxidative stress and pathogenesis and progression of AD, the use of antioxidants as preventive and management therapies have been well explored. Studies have shown that intake of antioxidants is linked with lower risk of dementia, AD and cognitive impairment in aged population (Grundman and Delaney 2002, Frank and Gupta 2005, Noguchi-Shinohara et al. 2018, Yeh et al. 2021). Therefore, several antioxidants and antioxidant-rich plant extracts have been reported promising for AD and cognitive impairments. Cholinergic system dysfunction is another important risk factor for AD. Cholinergic neurons utilise the neurotransmitter acetylcholine (ACh); these neurons have been shown to be involved in essential neurophysiological processes such attention, learning, memory, stress response, wakefulness and sleep, and sensory information (Picciotto et al. 2012 ). Damage to cholinergic neurons is believed to be involved in the etiology of AD and has been linked to cognitive impairment (Du et al. 2018). Hence, cholinesterase inhibitors were produced as a result, and they are still one of the most commonly used therapeutic medications to treat mild to moderate AD.
Phytol loaded PLGA nanoparticles ameliorate scopolamine-induced cognitive dysfunction by attenuating cholinesterase activity, oxidative stress and apoptosis in Wistar rat
Published in Nutritional Neuroscience, 2022
Sethuraman Sathya, Boovaragamoorthy Gowri Manogari, Kaliannan Thamaraiselvi, Sethuraman Vaidevi, Kandasamy Ruckmani, Kasi Pandima Devi
Alzheimer’s disease is an age-related disastrous neurodegenerative disorder characterized by impaired memory function, disorientation, and behavioral changes. During the progression of the disease, AD patients gradually lose their ability to think, communicate, make judgments, and take care of themselves. Epidemiological studies show that about 26.6 million people worldwide are affected by AD, which will quadruple to 106.8 million by 2050 [1,2]. In spite of the great advancement in the clinical research field, AD treatment remains a formidable task because of the intricacy of the targets and cross signaling between several pathways involved. The major neuropathological hallmarks of are the accumulation of neuritic plaques, neurofibrillary tangles, oxidative stress, metabolic disturbances, neurotransmitter dependency, glutamatergic toxicity, neuroinflammation and disruption of calcium homeostasis, which leads to neuronal cell death[3]. Moreover, the correct pathomechanism of cognitive impairment and neuronal deterioration in AD is still ambiguous. Currently, the cholinesterase inhibitors are used for the symptomatic treatment of AD. The use of cholinesterase inhibitors overcomes the depletion of the neurotransmitter acetylcholine in the cerebral cortex and hippocampus region of the brain. However, these drugs have limitations in clinical use due to their short half-lives and severe side effects. Moreover, it is only effective against mild to moderate forms of AD[4].
Frontal and subcortical contribution to visual hallucinations in dementia with Lewy bodies and Parkinson’s disease
Published in Postgraduate Medicine, 2019
Stefania Pezzoli, Annachiara Cagnin, Angelo Antonini, Annalena Venneri
Clinical diagnosis of DLB was based on the consensus criteria proposed by the DLB consortium [3]. DLB patients were included in the study if they presented mild to moderate cognitive decline, as assessed using a Mini-Mental State Examination (MMSE) test score cutoff of 18 or above. None of the patients presented severe cerebrovascular disease, assessed by brain CT or MRI scan, history of psychiatric disorders, and severe eye pathology impairing visual acuity (cataract, glaucoma, macular degeneration). Specifically, a neuro-ophthalmologic assessment was carried out including external inspection of the eyes, pupil reactions, penlight reflex, measure of near vision acuity, ocular movements and estimation of the visual field by confrontation test. Visual acuity and visual field were normal (or corrected to normal for visual acuity) in all patients. Medications used included: cholinesterase inhibitors, benzodiazepines, antidepressants. Neuroleptic drugs were taken by 45% of patients with VH and by one without VH. Only patients on a stable dose of cholinesterase inhibitors and/or levodopa for at least 3 months were included in the analyses.